105 files changed, 106277 insertions, 0 deletions

diff --git a/third_party/sqlite/src/alter.c b/third_party/sqlite/src/alter.c
new file mode 100755
index 0000000..ba929be
--- /dev/null
+++ b/third_party/sqlite/src/alter.c
@@ -0,0 +1,621 @@
+/*
+** 2005 February 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains C code routines that used to generate VDBE code
+** that implements the ALTER TABLE command.
+**
+** $Id: alter.c,v 1.47 2008/07/28 19:34:53 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+
+/*
+** The code in this file only exists if we are not omitting the
+** ALTER TABLE logic from the build.
+*/
+#ifndef SQLITE_OMIT_ALTERTABLE
+
+
+/*
+** This function is used by SQL generated to implement the 
+** ALTER TABLE command. The first argument is the text of a CREATE TABLE or
+** CREATE INDEX command. The second is a table name. The table name in 
+** the CREATE TABLE or CREATE INDEX statement is replaced with the third
+** argument and the result returned. Examples:
+**
+** sqlite_rename_table('CREATE TABLE abc(a, b, c)', 'def')
+**     -> 'CREATE TABLE def(a, b, c)'
+**
+** sqlite_rename_table('CREATE INDEX i ON abc(a)', 'def')
+**     -> 'CREATE INDEX i ON def(a, b, c)'
+*/
+static void renameTableFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  unsigned char const *zSql = sqlite3_value_text(argv[0]);
+  unsigned char const *zTableName = sqlite3_value_text(argv[1]);
+
+  int token;
+  Token tname;
+  unsigned char const *zCsr = zSql;
+  int len = 0;
+  char *zRet;
+
+  sqlite3 *db = sqlite3_context_db_handle(context);
+
+  /* The principle used to locate the table name in the CREATE TABLE 
+  ** statement is that the table name is the first non-space token that
+  ** is immediately followed by a TK_LP or TK_USING token.
+  */
+  if( zSql ){
+    do {
+      if( !*zCsr ){
+        /* Ran out of input before finding an opening bracket. Return NULL. */
+        return;
+      }
+
+      /* Store the token that zCsr points to in tname. */
+      tname.z = zCsr;
+      tname.n = len;
+
+      /* Advance zCsr to the next token. Store that token type in 'token',
+      ** and its length in 'len' (to be used next iteration of this loop).
+      */
+      do {
+        zCsr += len;
+        len = sqlite3GetToken(zCsr, &token);
+      } while( token==TK_SPACE || token==TK_COMMENT );
+      assert( len>0 );
+    } while( token!=TK_LP && token!=TK_USING );
+
+    zRet = sqlite3MPrintf(db, "%.*s\"%w\"%s", tname.z - zSql, zSql, 
+       zTableName, tname.z+tname.n);
+    sqlite3_result_text(context, zRet, -1, SQLITE_DYNAMIC);
+  }
+}
+
+#ifndef SQLITE_OMIT_TRIGGER
+/* This function is used by SQL generated to implement the
+** ALTER TABLE command. The first argument is the text of a CREATE TRIGGER 
+** statement. The second is a table name. The table name in the CREATE 
+** TRIGGER statement is replaced with the third argument and the result 
+** returned. This is analagous to renameTableFunc() above, except for CREATE
+** TRIGGER, not CREATE INDEX and CREATE TABLE.
+*/
+static void renameTriggerFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  unsigned char const *zSql = sqlite3_value_text(argv[0]);
+  unsigned char const *zTableName = sqlite3_value_text(argv[1]);
+
+  int token;
+  Token tname;
+  int dist = 3;
+  unsigned char const *zCsr = zSql;
+  int len = 0;
+  char *zRet;
+
+  sqlite3 *db = sqlite3_context_db_handle(context);
+
+  /* The principle used to locate the table name in the CREATE TRIGGER 
+  ** statement is that the table name is the first token that is immediatedly
+  ** preceded by either TK_ON or TK_DOT and immediatedly followed by one
+  ** of TK_WHEN, TK_BEGIN or TK_FOR.
+  */
+  if( zSql ){
+    do {
+
+      if( !*zCsr ){
+        /* Ran out of input before finding the table name. Return NULL. */
+        return;
+      }
+
+      /* Store the token that zCsr points to in tname. */
+      tname.z = zCsr;
+      tname.n = len;
+
+      /* Advance zCsr to the next token. Store that token type in 'token',
+      ** and its length in 'len' (to be used next iteration of this loop).
+      */
+      do {
+        zCsr += len;
+        len = sqlite3GetToken(zCsr, &token);
+      }while( token==TK_SPACE );
+      assert( len>0 );
+
+      /* Variable 'dist' stores the number of tokens read since the most
+      ** recent TK_DOT or TK_ON. This means that when a WHEN, FOR or BEGIN 
+      ** token is read and 'dist' equals 2, the condition stated above
+      ** to be met.
+      **
+      ** Note that ON cannot be a database, table or column name, so
+      ** there is no need to worry about syntax like 
+      ** "CREATE TRIGGER ... ON ON.ON BEGIN ..." etc.
+      */
+      dist++;
+      if( token==TK_DOT || token==TK_ON ){
+        dist = 0;
+      }
+    } while( dist!=2 || (token!=TK_WHEN && token!=TK_FOR && token!=TK_BEGIN) );
+
+    /* Variable tname now contains the token that is the old table-name
+    ** in the CREATE TRIGGER statement.
+    */
+    zRet = sqlite3MPrintf(db, "%.*s\"%w\"%s", tname.z - zSql, zSql, 
+       zTableName, tname.z+tname.n);
+    sqlite3_result_text(context, zRet, -1, SQLITE_DYNAMIC);
+  }
+}
+#endif   /* !SQLITE_OMIT_TRIGGER */
+
+/*
+** Register built-in functions used to help implement ALTER TABLE
+*/
+void sqlite3AlterFunctions(sqlite3 *db){
+  sqlite3CreateFunc(db, "sqlite_rename_table", 2, SQLITE_UTF8, 0,
+                         renameTableFunc, 0, 0);
+#ifndef SQLITE_OMIT_TRIGGER
+  sqlite3CreateFunc(db, "sqlite_rename_trigger", 2, SQLITE_UTF8, 0,
+                         renameTriggerFunc, 0, 0);
+#endif
+}
+
+/*
+** Generate the text of a WHERE expression which can be used to select all
+** temporary triggers on table pTab from the sqlite_temp_master table. If
+** table pTab has no temporary triggers, or is itself stored in the 
+** temporary database, NULL is returned.
+*/
+static char *whereTempTriggers(Parse *pParse, Table *pTab){
+  Trigger *pTrig;
+  char *zWhere = 0;
+  char *tmp = 0;
+  const Schema *pTempSchema = pParse->db->aDb[1].pSchema; /* Temp db schema */
+
+  /* If the table is not located in the temp-db (in which case NULL is 
+  ** returned, loop through the tables list of triggers. For each trigger
+  ** that is not part of the temp-db schema, add a clause to the WHERE 
+  ** expression being built up in zWhere.
+  */
+  if( pTab->pSchema!=pTempSchema ){
+    sqlite3 *db = pParse->db;
+    for( pTrig=pTab->pTrigger; pTrig; pTrig=pTrig->pNext ){
+      if( pTrig->pSchema==pTempSchema ){
+        if( !zWhere ){
+          zWhere = sqlite3MPrintf(db, "name=%Q", pTrig->name);
+        }else{
+          tmp = zWhere;
+          zWhere = sqlite3MPrintf(db, "%s OR name=%Q", zWhere, pTrig->name);
+          sqlite3DbFree(db, tmp);
+        }
+      }
+    }
+  }
+  return zWhere;
+}
+
+/*
+** Generate code to drop and reload the internal representation of table
+** pTab from the database, including triggers and temporary triggers.
+** Argument zName is the name of the table in the database schema at
+** the time the generated code is executed. This can be different from
+** pTab->zName if this function is being called to code part of an 
+** "ALTER TABLE RENAME TO" statement.
+*/
+static void reloadTableSchema(Parse *pParse, Table *pTab, const char *zName){
+  Vdbe *v;
+  char *zWhere;
+  int iDb;                   /* Index of database containing pTab */
+#ifndef SQLITE_OMIT_TRIGGER
+  Trigger *pTrig;
+#endif
+
+  v = sqlite3GetVdbe(pParse);
+  if( !v ) return;
+  assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
+  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+  assert( iDb>=0 );
+
+#ifndef SQLITE_OMIT_TRIGGER
+  /* Drop any table triggers from the internal schema. */
+  for(pTrig=pTab->pTrigger; pTrig; pTrig=pTrig->pNext){
+    int iTrigDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
+    assert( iTrigDb==iDb || iTrigDb==1 );
+    sqlite3VdbeAddOp4(v, OP_DropTrigger, iTrigDb, 0, 0, pTrig->name, 0);
+  }
+#endif
+
+  /* Drop the table and index from the internal schema */
+  sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0);
+
+  /* Reload the table, index and permanent trigger schemas. */
+  zWhere = sqlite3MPrintf(pParse->db, "tbl_name=%Q", zName);
+  if( !zWhere ) return;
+  sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0, zWhere, P4_DYNAMIC);
+
+#ifndef SQLITE_OMIT_TRIGGER
+  /* Now, if the table is not stored in the temp database, reload any temp 
+  ** triggers. Don't use IN(...) in case SQLITE_OMIT_SUBQUERY is defined. 
+  */
+  if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
+    sqlite3VdbeAddOp4(v, OP_ParseSchema, 1, 0, 0, zWhere, P4_DYNAMIC);
+  }
+#endif
+}
+
+/*
+** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy" 
+** command. 
+*/
+void sqlite3AlterRenameTable(
+  Parse *pParse,            /* Parser context. */
+  SrcList *pSrc,            /* The table to rename. */
+  Token *pName              /* The new table name. */
+){
+  int iDb;                  /* Database that contains the table */
+  char *zDb;                /* Name of database iDb */
+  Table *pTab;              /* Table being renamed */
+  char *zName = 0;          /* NULL-terminated version of pName */ 
+  sqlite3 *db = pParse->db; /* Database connection */
+  int nTabName;             /* Number of UTF-8 characters in zTabName */
+  const char *zTabName;     /* Original name of the table */
+  Vdbe *v;
+#ifndef SQLITE_OMIT_TRIGGER
+  char *zWhere = 0;         /* Where clause to locate temp triggers */
+#endif
+  int isVirtualRename = 0;  /* True if this is a v-table with an xRename() */
+  
+  if( db->mallocFailed ) goto exit_rename_table;
+  assert( pSrc->nSrc==1 );
+  assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
+
+  pTab = sqlite3LocateTable(pParse, 0, pSrc->a[0].zName, pSrc->a[0].zDatabase);
+  if( !pTab ) goto exit_rename_table;
+  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+  zDb = db->aDb[iDb].zName;
+
+  /* Get a NULL terminated version of the new table name. */
+  zName = sqlite3NameFromToken(db, pName);
+  if( !zName ) goto exit_rename_table;
+
+  /* Check that a table or index named 'zName' does not already exist
+  ** in database iDb. If so, this is an error.
+  */
+  if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){
+    sqlite3ErrorMsg(pParse, 
+        "there is already another table or index with this name: %s", zName);
+    goto exit_rename_table;
+  }
+
+  /* Make sure it is not a system table being altered, or a reserved name
+  ** that the table is being renamed to.
+  */
+  if( strlen(pTab->zName)>6 && 0==sqlite3StrNICmp(pTab->zName, "sqlite_", 7) ){
+    sqlite3ErrorMsg(pParse, "table %s may not be altered", pTab->zName);
+    goto exit_rename_table;
+  }
+  if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
+    goto exit_rename_table;
+  }
+
+#ifndef SQLITE_OMIT_VIEW
+  if( pTab->pSelect ){
+    sqlite3ErrorMsg(pParse, "view %s may not be altered", pTab->zName);
+    goto exit_rename_table;
+  }
+#endif
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  /* Invoke the authorization callback. */
+  if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
+    goto exit_rename_table;
+  }
+#endif
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
+    goto exit_rename_table;
+  }
+  if( IsVirtual(pTab) && pTab->pMod->pModule->xRename ){
+    isVirtualRename = 1;
+  }
+#endif
+
+  /* Begin a transaction and code the VerifyCookie for database iDb. 
+  ** Then modify the schema cookie (since the ALTER TABLE modifies the
+  ** schema). Open a statement transaction if the table is a virtual
+  ** table.
+  */
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 ){
+    goto exit_rename_table;
+  }
+  sqlite3BeginWriteOperation(pParse, isVirtualRename, iDb);
+  sqlite3ChangeCookie(pParse, iDb);
+
+  /* If this is a virtual table, invoke the xRename() function if
+  ** one is defined. The xRename() callback will modify the names
+  ** of any resources used by the v-table implementation (including other
+  ** SQLite tables) that are identified by the name of the virtual table.
+  */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if( isVirtualRename ){
+    int i = ++pParse->nMem;
+    sqlite3VdbeAddOp4(v, OP_String8, 0, i, 0, zName, 0);
+    sqlite3VdbeAddOp4(v, OP_VRename, i, 0, 0,(const char*)pTab->pVtab, P4_VTAB);
+  }
+#endif
+
+  /* figure out how many UTF-8 characters are in zName */
+  zTabName = pTab->zName;
+  nTabName = sqlite3Utf8CharLen(zTabName, -1);
+
+  /* Modify the sqlite_master table to use the new table name. */
+  sqlite3NestedParse(pParse,
+      "UPDATE %Q.%s SET "
+#ifdef SQLITE_OMIT_TRIGGER
+          "sql = sqlite_rename_table(sql, %Q), "
+#else
+          "sql = CASE "
+            "WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
+            "ELSE sqlite_rename_table(sql, %Q) END, "
+#endif
+          "tbl_name = %Q, "
+          "name = CASE "
+            "WHEN type='table' THEN %Q "
+            "WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
+             "'sqlite_autoindex_' || %Q || substr(name,%d+18) "
+            "ELSE name END "
+      "WHERE tbl_name=%Q AND "
+          "(type='table' OR type='index' OR type='trigger');", 
+      zDb, SCHEMA_TABLE(iDb), zName, zName, zName, 
+#ifndef SQLITE_OMIT_TRIGGER
+      zName,
+#endif
+      zName, nTabName, zTabName
+  );
+
+#ifndef SQLITE_OMIT_AUTOINCREMENT
+  /* If the sqlite_sequence table exists in this database, then update 
+  ** it with the new table name.
+  */
+  if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){
+    sqlite3NestedParse(pParse,
+        "UPDATE \"%w\".sqlite_sequence set name = %Q WHERE name = %Q",
+        zDb, zName, pTab->zName);
+  }
+#endif
+
+#ifndef SQLITE_OMIT_TRIGGER
+  /* If there are TEMP triggers on this table, modify the sqlite_temp_master
+  ** table. Don't do this if the table being ALTERed is itself located in
+  ** the temp database.
+  */
+  if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
+    sqlite3NestedParse(pParse, 
+        "UPDATE sqlite_temp_master SET "
+            "sql = sqlite_rename_trigger(sql, %Q), "
+            "tbl_name = %Q "
+            "WHERE %s;", zName, zName, zWhere);
+    sqlite3DbFree(db, zWhere);
+  }
+#endif
+
+  /* Drop and reload the internal table schema. */
+  reloadTableSchema(pParse, pTab, zName);
+
+exit_rename_table:
+  sqlite3SrcListDelete(db, pSrc);
+  sqlite3DbFree(db, zName);
+}
+
+
+/*
+** This function is called after an "ALTER TABLE ... ADD" statement
+** has been parsed. Argument pColDef contains the text of the new
+** column definition.
+**
+** The Table structure pParse->pNewTable was extended to include
+** the new column during parsing.
+*/
+void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
+  Table *pNew;              /* Copy of pParse->pNewTable */
+  Table *pTab;              /* Table being altered */
+  int iDb;                  /* Database number */
+  const char *zDb;          /* Database name */
+  const char *zTab;         /* Table name */
+  char *zCol;               /* Null-terminated column definition */
+  Column *pCol;             /* The new column */
+  Expr *pDflt;              /* Default value for the new column */
+  sqlite3 *db;              /* The database connection; */
+
+  if( pParse->nErr ) return;
+  pNew = pParse->pNewTable;
+  assert( pNew );
+
+  db = pParse->db;
+  assert( sqlite3BtreeHoldsAllMutexes(db) );
+  iDb = sqlite3SchemaToIndex(db, pNew->pSchema);
+  zDb = db->aDb[iDb].zName;
+  zTab = pNew->zName;
+  pCol = &pNew->aCol[pNew->nCol-1];
+  pDflt = pCol->pDflt;
+  pTab = sqlite3FindTable(db, zTab, zDb);
+  assert( pTab );
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  /* Invoke the authorization callback. */
+  if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
+    return;
+  }
+#endif
+
+  /* If the default value for the new column was specified with a 
+  ** literal NULL, then set pDflt to 0. This simplifies checking
+  ** for an SQL NULL default below.
+  */
+  if( pDflt && pDflt->op==TK_NULL ){
+    pDflt = 0;
+  }
+
+  /* Check that the new column is not specified as PRIMARY KEY or UNIQUE.
+  ** If there is a NOT NULL constraint, then the default value for the
+  ** column must not be NULL.
+  */
+  if( pCol->isPrimKey ){
+    sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");
+    return;
+  }
+  if( pNew->pIndex ){
+    sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column");
+    return;
+  }
+  if( pCol->notNull && !pDflt ){
+    sqlite3ErrorMsg(pParse, 
+        "Cannot add a NOT NULL column with default value NULL");
+    return;
+  }
+
+  /* Ensure the default expression is something that sqlite3ValueFromExpr()
+  ** can handle (i.e. not CURRENT_TIME etc.)
+  */
+  if( pDflt ){
+    sqlite3_value *pVal;
+    if( sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_NONE, &pVal) ){
+      db->mallocFailed = 1;
+      return;
+    }
+    if( !pVal ){
+      sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default");
+      return;
+    }
+    sqlite3ValueFree(pVal);
+  }
+
+  /* Modify the CREATE TABLE statement. */
+  zCol = sqlite3DbStrNDup(db, (char*)pColDef->z, pColDef->n);
+  if( zCol ){
+    char *zEnd = &zCol[pColDef->n-1];
+    while( (zEnd>zCol && *zEnd==';') || isspace(*(unsigned char *)zEnd) ){
+      *zEnd-- = '\0';
+    }
+    sqlite3NestedParse(pParse, 
+        "UPDATE \"%w\".%s SET "
+          "sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "
+        "WHERE type = 'table' AND name = %Q", 
+      zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1,
+      zTab
+    );
+    sqlite3DbFree(db, zCol);
+  }
+
+  /* If the default value of the new column is NULL, then set the file
+  ** format to 2. If the default value of the new column is not NULL,
+  ** the file format becomes 3.
+  */
+  sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2);
+
+  /* Reload the schema of the modified table. */
+  reloadTableSchema(pParse, pTab, pTab->zName);
+}
+
+/*
+** This function is called by the parser after the table-name in
+** an "ALTER TABLE <table-name> ADD" statement is parsed. Argument 
+** pSrc is the full-name of the table being altered.
+**
+** This routine makes a (partial) copy of the Table structure
+** for the table being altered and sets Parse.pNewTable to point
+** to it. Routines called by the parser as the column definition
+** is parsed (i.e. sqlite3AddColumn()) add the new Column data to 
+** the copy. The copy of the Table structure is deleted by tokenize.c 
+** after parsing is finished.
+**
+** Routine sqlite3AlterFinishAddColumn() will be called to complete
+** coding the "ALTER TABLE ... ADD" statement.
+*/
+void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
+  Table *pNew;
+  Table *pTab;
+  Vdbe *v;
+  int iDb;
+  int i;
+  int nAlloc;
+  sqlite3 *db = pParse->db;
+
+  /* Look up the table being altered. */
+  assert( pParse->pNewTable==0 );
+  assert( sqlite3BtreeHoldsAllMutexes(db) );
+  if( db->mallocFailed ) goto exit_begin_add_column;
+  pTab = sqlite3LocateTable(pParse, 0, pSrc->a[0].zName, pSrc->a[0].zDatabase);
+  if( !pTab ) goto exit_begin_add_column;
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if( IsVirtual(pTab) ){
+    sqlite3ErrorMsg(pParse, "virtual tables may not be altered");
+    goto exit_begin_add_column;
+  }
+#endif
+
+  /* Make sure this is not an attempt to ALTER a view. */
+  if( pTab->pSelect ){
+    sqlite3ErrorMsg(pParse, "Cannot add a column to a view");
+    goto exit_begin_add_column;
+  }
+
+  assert( pTab->addColOffset>0 );
+  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+
+  /* Put a copy of the Table struct in Parse.pNewTable for the
+  ** sqlite3AddColumn() function and friends to modify.
+  */
+  pNew = (Table*)sqlite3DbMallocZero(db, sizeof(Table));
+  if( !pNew ) goto exit_begin_add_column;
+  pParse->pNewTable = pNew;
+  pNew->nRef = 1;
+  pNew->db = db;
+  pNew->nCol = pTab->nCol;
+  assert( pNew->nCol>0 );
+  nAlloc = (((pNew->nCol-1)/8)*8)+8;
+  assert( nAlloc>=pNew->nCol && nAlloc%8==0 && nAlloc-pNew->nCol<8 );
+  pNew->aCol = (Column*)sqlite3DbMallocZero(db, sizeof(Column)*nAlloc);
+  pNew->zName = sqlite3DbStrDup(db, pTab->zName);
+  if( !pNew->aCol || !pNew->zName ){
+    db->mallocFailed = 1;
+    goto exit_begin_add_column;
+  }
+  memcpy(pNew->aCol, pTab->aCol, sizeof(Column)*pNew->nCol);
+  for(i=0; i<pNew->nCol; i++){
+    Column *pCol = &pNew->aCol[i];
+    pCol->zName = sqlite3DbStrDup(db, pCol->zName);
+    pCol->zColl = 0;
+    pCol->zType = 0;
+    pCol->pDflt = 0;
+  }
+  pNew->pSchema = db->aDb[iDb].pSchema;
+  pNew->addColOffset = pTab->addColOffset;
+  pNew->nRef = 1;
+
+  /* Begin a transaction and increment the schema cookie.  */
+  sqlite3BeginWriteOperation(pParse, 0, iDb);
+  v = sqlite3GetVdbe(pParse);
+  if( !v ) goto exit_begin_add_column;
+  sqlite3ChangeCookie(pParse, iDb);
+
+exit_begin_add_column:
+  sqlite3SrcListDelete(db, pSrc);
+  return;
+}
+#endif  /* SQLITE_ALTER_TABLE */
diff --git a/third_party/sqlite/src/analyze.c b/third_party/sqlite/src/analyze.c
new file mode 100755
index 0000000..2c57d7f
--- /dev/null
+++ b/third_party/sqlite/src/analyze.c
@@ -0,0 +1,425 @@
+/*
+** 2005 July 8
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code associated with the ANALYZE command.
+**
+** @(#) $Id: analyze.c,v 1.43 2008/07/28 19:34:53 drh Exp $
+*/
+#ifndef SQLITE_OMIT_ANALYZE
+#include "sqliteInt.h"
+
+/*
+** This routine generates code that opens the sqlite_stat1 table on cursor
+** iStatCur.
+**
+** If the sqlite_stat1 tables does not previously exist, it is created.
+** If it does previously exist, all entires associated with table zWhere
+** are removed.  If zWhere==0 then all entries are removed.
+*/
+static void openStatTable(
+  Parse *pParse,          /* Parsing context */
+  int iDb,                /* The database we are looking in */
+  int iStatCur,           /* Open the sqlite_stat1 table on this cursor */
+  const char *zWhere      /* Delete entries associated with this table */
+){
+  sqlite3 *db = pParse->db;
+  Db *pDb;
+  int iRootPage;
+  int createStat1 = 0;
+  Table *pStat;
+  Vdbe *v = sqlite3GetVdbe(pParse);
+
+  if( v==0 ) return;
+  assert( sqlite3BtreeHoldsAllMutexes(db) );
+  assert( sqlite3VdbeDb(v)==db );
+  pDb = &db->aDb[iDb];
+  if( (pStat = sqlite3FindTable(db, "sqlite_stat1", pDb->zName))==0 ){
+    /* The sqlite_stat1 tables does not exist.  Create it.  
+    ** Note that a side-effect of the CREATE TABLE statement is to leave
+    ** the rootpage of the new table in register pParse->regRoot.  This is
+    ** important because the OpenWrite opcode below will be needing it. */
+    sqlite3NestedParse(pParse,
+      "CREATE TABLE %Q.sqlite_stat1(tbl,idx,stat)",
+      pDb->zName
+    );
+    iRootPage = pParse->regRoot;
+    createStat1 = 1;  /* Cause rootpage to be taken from top of stack */
+  }else if( zWhere ){
+    /* The sqlite_stat1 table exists.  Delete all entries associated with
+    ** the table zWhere. */
+    sqlite3NestedParse(pParse,
+       "DELETE FROM %Q.sqlite_stat1 WHERE tbl=%Q",
+       pDb->zName, zWhere
+    );
+    iRootPage = pStat->tnum;
+  }else{
+    /* The sqlite_stat1 table already exists.  Delete all rows. */
+    iRootPage = pStat->tnum;
+    sqlite3VdbeAddOp2(v, OP_Clear, pStat->tnum, iDb);
+  }
+
+  /* Open the sqlite_stat1 table for writing. Unless it was created
+  ** by this vdbe program, lock it for writing at the shared-cache level. 
+  ** If this vdbe did create the sqlite_stat1 table, then it must have 
+  ** already obtained a schema-lock, making the write-lock redundant.
+  */
+  if( !createStat1 ){
+    sqlite3TableLock(pParse, iDb, iRootPage, 1, "sqlite_stat1");
+  }
+  sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, 3);
+  sqlite3VdbeAddOp3(v, OP_OpenWrite, iStatCur, iRootPage, iDb);
+  sqlite3VdbeChangeP5(v, createStat1);
+}
+
+/*
+** Generate code to do an analysis of all indices associated with
+** a single table.
+*/
+static void analyzeOneTable(
+  Parse *pParse,   /* Parser context */
+  Table *pTab,     /* Table whose indices are to be analyzed */
+  int iStatCur,    /* Cursor that writes to the sqlite_stat1 table */
+  int iMem         /* Available memory locations begin here */
+){
+  Index *pIdx;     /* An index to being analyzed */
+  int iIdxCur;     /* Cursor number for index being analyzed */
+  int nCol;        /* Number of columns in the index */
+  Vdbe *v;         /* The virtual machine being built up */
+  int i;           /* Loop counter */
+  int topOfLoop;   /* The top of the loop */
+  int endOfLoop;   /* The end of the loop */
+  int addr;        /* The address of an instruction */
+  int iDb;         /* Index of database containing pTab */
+
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 || pTab==0 || pTab->pIndex==0 ){
+    /* Do no analysis for tables that have no indices */
+    return;
+  }
+  assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
+  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+  assert( iDb>=0 );
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0,
+      pParse->db->aDb[iDb].zName ) ){
+    return;
+  }
+#endif
+
+  /* Establish a read-lock on the table at the shared-cache level. */
+  sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
+
+  iIdxCur = pParse->nTab;
+  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
+    int regFields;    /* Register block for building records */
+    int regRec;       /* Register holding completed record */
+    int regTemp;      /* Temporary use register */
+    int regCol;       /* Content of a column from the table being analyzed */
+    int regRowid;     /* Rowid for the inserted record */
+    int regF2;
+
+    /* Open a cursor to the index to be analyzed
+    */
+    assert( iDb==sqlite3SchemaToIndex(pParse->db, pIdx->pSchema) );
+    nCol = pIdx->nColumn;
+    sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, nCol+1);
+    sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb,
+        (char *)pKey, P4_KEYINFO_HANDOFF);
+    VdbeComment((v, "%s", pIdx->zName));
+    regFields = iMem+nCol*2;
+    regTemp = regRowid = regCol = regFields+3;
+    regRec = regCol+1;
+    if( regRec>pParse->nMem ){
+      pParse->nMem = regRec;
+    }
+
+    /* Memory cells are used as follows:
+    **
+    **    mem[iMem]:             The total number of rows in the table.
+    **    mem[iMem+1]:           Number of distinct values in column 1
+    **    ...
+    **    mem[iMem+nCol]:        Number of distinct values in column N
+    **    mem[iMem+nCol+1]       Last observed value of column 1
+    **    ...
+    **    mem[iMem+nCol+nCol]:   Last observed value of column N
+    **
+    ** Cells iMem through iMem+nCol are initialized to 0.  The others
+    ** are initialized to NULL.
+    */
+    for(i=0; i<=nCol; i++){
+      sqlite3VdbeAddOp2(v, OP_Integer, 0, iMem+i);
+    }
+    for(i=0; i<nCol; i++){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, iMem+nCol+i+1);
+    }
+
+    /* Do the analysis.
+    */
+    endOfLoop = sqlite3VdbeMakeLabel(v);
+    sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop);
+    topOfLoop = sqlite3VdbeCurrentAddr(v);
+    sqlite3VdbeAddOp2(v, OP_AddImm, iMem, 1);
+    for(i=0; i<nCol; i++){
+      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regCol);
+      sqlite3VdbeAddOp3(v, OP_Ne, regCol, 0, iMem+nCol+i+1);
+      /**** TODO:  add collating sequence *****/
+      sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
+    }
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, endOfLoop);
+    for(i=0; i<nCol; i++){
+      sqlite3VdbeJumpHere(v, topOfLoop + 2*(i + 1));
+      sqlite3VdbeAddOp2(v, OP_AddImm, iMem+i+1, 1);
+      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, iMem+nCol+i+1);
+    }
+    sqlite3VdbeResolveLabel(v, endOfLoop);
+    sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop);
+    sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);
+
+    /* Store the results.  
+    **
+    ** The result is a single row of the sqlite_stat1 table.  The first
+    ** two columns are the names of the table and index.  The third column
+    ** is a string composed of a list of integer statistics about the
+    ** index.  The first integer in the list is the total number of entires
+    ** in the index.  There is one additional integer in the list for each
+    ** column of the table.  This additional integer is a guess of how many
+    ** rows of the table the index will select.  If D is the count of distinct
+    ** values and K is the total number of rows, then the integer is computed
+    ** as:
+    **
+    **        I = (K+D-1)/D
+    **
+    ** If K==0 then no entry is made into the sqlite_stat1 table.  
+    ** If K>0 then it is always the case the D>0 so division by zero
+    ** is never possible.
+    */
+    addr = sqlite3VdbeAddOp1(v, OP_IfNot, iMem);
+    sqlite3VdbeAddOp4(v, OP_String8, 0, regFields, 0, pTab->zName, 0);
+    sqlite3VdbeAddOp4(v, OP_String8, 0, regFields+1, 0, pIdx->zName, 0);
+    regF2 = regFields+2;
+    sqlite3VdbeAddOp2(v, OP_SCopy, iMem, regF2);
+    for(i=0; i<nCol; i++){
+      sqlite3VdbeAddOp4(v, OP_String8, 0, regTemp, 0, " ", 0);
+      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regF2, regF2);
+      sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp);
+      sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1);
+      sqlite3VdbeAddOp3(v, OP_Divide, iMem+i+1, regTemp, regTemp);
+      sqlite3VdbeAddOp1(v, OP_ToInt, regTemp);
+      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regF2, regF2);
+    }
+    sqlite3VdbeAddOp4(v, OP_MakeRecord, regFields, 3, regRec, "aaa", 0);
+    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid);
+    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid);
+    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
+    sqlite3VdbeJumpHere(v, addr);
+  }
+}
+
+/*
+** Generate code that will cause the most recent index analysis to
+** be laoded into internal hash tables where is can be used.
+*/
+static void loadAnalysis(Parse *pParse, int iDb){
+  Vdbe *v = sqlite3GetVdbe(pParse);
+  if( v ){
+    sqlite3VdbeAddOp1(v, OP_LoadAnalysis, iDb);
+  }
+}
+
+/*
+** Generate code that will do an analysis of an entire database
+*/
+static void analyzeDatabase(Parse *pParse, int iDb){
+  sqlite3 *db = pParse->db;
+  Schema *pSchema = db->aDb[iDb].pSchema;    /* Schema of database iDb */
+  HashElem *k;
+  int iStatCur;
+  int iMem;
+
+  sqlite3BeginWriteOperation(pParse, 0, iDb);
+  iStatCur = pParse->nTab++;
+  openStatTable(pParse, iDb, iStatCur, 0);
+  iMem = pParse->nMem+1;
+  for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
+    Table *pTab = (Table*)sqliteHashData(k);
+    analyzeOneTable(pParse, pTab, iStatCur, iMem);
+  }
+  loadAnalysis(pParse, iDb);
+}
+
+/*
+** Generate code that will do an analysis of a single table in
+** a database.
+*/
+static void analyzeTable(Parse *pParse, Table *pTab){
+  int iDb;
+  int iStatCur;
+
+  assert( pTab!=0 );
+  assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
+  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+  sqlite3BeginWriteOperation(pParse, 0, iDb);
+  iStatCur = pParse->nTab++;
+  openStatTable(pParse, iDb, iStatCur, pTab->zName);
+  analyzeOneTable(pParse, pTab, iStatCur, pParse->nMem+1);
+  loadAnalysis(pParse, iDb);
+}
+
+/*
+** Generate code for the ANALYZE command.  The parser calls this routine
+** when it recognizes an ANALYZE command.
+**
+**        ANALYZE                            -- 1
+**        ANALYZE  <database>                -- 2
+**        ANALYZE  ?<database>.?<tablename>  -- 3
+**
+** Form 1 causes all indices in all attached databases to be analyzed.
+** Form 2 analyzes all indices the single database named.
+** Form 3 analyzes all indices associated with the named table.
+*/
+void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){
+  sqlite3 *db = pParse->db;
+  int iDb;
+  int i;
+  char *z, *zDb;
+  Table *pTab;
+  Token *pTableName;
+
+  /* Read the database schema. If an error occurs, leave an error message
+  ** and code in pParse and return NULL. */
+  assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
+  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
+    return;
+  }
+
+  if( pName1==0 ){
+    /* Form 1:  Analyze everything */
+    for(i=0; i<db->nDb; i++){
+      if( i==1 ) continue;  /* Do not analyze the TEMP database */
+      analyzeDatabase(pParse, i);
+    }
+  }else if( pName2==0 || pName2->n==0 ){
+    /* Form 2:  Analyze the database or table named */
+    iDb = sqlite3FindDb(db, pName1);
+    if( iDb>=0 ){
+      analyzeDatabase(pParse, iDb);
+    }else{
+      z = sqlite3NameFromToken(db, pName1);
+      if( z ){
+        pTab = sqlite3LocateTable(pParse, 0, z, 0);
+        sqlite3DbFree(db, z);
+        if( pTab ){
+          analyzeTable(pParse, pTab);
+        }
+      }
+    }
+  }else{
+    /* Form 3: Analyze the fully qualified table name */
+    iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pTableName);
+    if( iDb>=0 ){
+      zDb = db->aDb[iDb].zName;
+      z = sqlite3NameFromToken(db, pTableName);
+      if( z ){
+        pTab = sqlite3LocateTable(pParse, 0, z, zDb);
+        sqlite3DbFree(db, z);
+        if( pTab ){
+          analyzeTable(pParse, pTab);
+        }
+      }
+    }   
+  }
+}
+
+/*
+** Used to pass information from the analyzer reader through to the
+** callback routine.
+*/
+typedef struct analysisInfo analysisInfo;
+struct analysisInfo {
+  sqlite3 *db;
+  const char *zDatabase;
+};
+
+/*
+** This callback is invoked once for each index when reading the
+** sqlite_stat1 table.  
+**
+**     argv[0] = name of the index
+**     argv[1] = results of analysis - on integer for each column
+*/
+static int analysisLoader(void *pData, int argc, char **argv, char **azNotUsed){
+  analysisInfo *pInfo = (analysisInfo*)pData;
+  Index *pIndex;
+  int i, c;
+  unsigned int v;
+  const char *z;
+
+  assert( argc==2 );
+  if( argv==0 || argv[0]==0 || argv[1]==0 ){
+    return 0;
+  }
+  pIndex = sqlite3FindIndex(pInfo->db, argv[0], pInfo->zDatabase);
+  if( pIndex==0 ){
+    return 0;
+  }
+  z = argv[1];
+  for(i=0; *z && i<=pIndex->nColumn; i++){
+    v = 0;
+    while( (c=z[0])>='0' && c<='9' ){
+      v = v*10 + c - '0';
+      z++;
+    }
+    pIndex->aiRowEst[i] = v;
+    if( *z==' ' ) z++;
+  }
+  return 0;
+}
+
+/*
+** Load the content of the sqlite_stat1 table into the index hash tables.
+*/
+int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
+  analysisInfo sInfo;
+  HashElem *i;
+  char *zSql;
+  int rc;
+
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( db->aDb[iDb].pBt!=0 );
+  assert( sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
+
+  /* Clear any prior statistics */
+  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
+    Index *pIdx = sqliteHashData(i);
+    sqlite3DefaultRowEst(pIdx);
+  }
+
+  /* Check to make sure the sqlite_stat1 table existss */
+  sInfo.db = db;
+  sInfo.zDatabase = db->aDb[iDb].zName;
+  if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)==0 ){
+     return SQLITE_ERROR;
+  }
+
+
+  /* Load new statistics out of the sqlite_stat1 table */
+  zSql = sqlite3MPrintf(db, "SELECT idx, stat FROM %Q.sqlite_stat1",
+                        sInfo.zDatabase);
+  (void)sqlite3SafetyOff(db);
+  rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);
+  (void)sqlite3SafetyOn(db);
+  sqlite3DbFree(db, zSql);
+  return rc;
+}
+
+
+#endif /* SQLITE_OMIT_ANALYZE */
diff --git a/third_party/sqlite/src/attach.c b/third_party/sqlite/src/attach.c
new file mode 100755
index 0000000..b8668f5
--- /dev/null
+++ b/third_party/sqlite/src/attach.c
@@ -0,0 +1,524 @@
+/*
+** 2003 April 6
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code used to implement the ATTACH and DETACH commands.
+**
+** $Id: attach.c,v 1.77 2008/07/28 19:34:53 drh Exp $
+*/
+#include "sqliteInt.h"
+
+#ifndef SQLITE_OMIT_ATTACH
+/*
+** Resolve an expression that was part of an ATTACH or DETACH statement. This
+** is slightly different from resolving a normal SQL expression, because simple
+** identifiers are treated as strings, not possible column names or aliases.
+**
+** i.e. if the parser sees:
+**
+**     ATTACH DATABASE abc AS def
+**
+** it treats the two expressions as literal strings 'abc' and 'def' instead of
+** looking for columns of the same name.
+**
+** This only applies to the root node of pExpr, so the statement:
+**
+**     ATTACH DATABASE abc||def AS 'db2'
+**
+** will fail because neither abc or def can be resolved.
+*/
+static int resolveAttachExpr(NameContext *pName, Expr *pExpr)
+{
+  int rc = SQLITE_OK;
+  if( pExpr ){
+    if( pExpr->op!=TK_ID ){
+      rc = sqlite3ExprResolveNames(pName, pExpr);
+      if( rc==SQLITE_OK && !sqlite3ExprIsConstant(pExpr) ){
+        sqlite3ErrorMsg(pName->pParse, "invalid name: \"%T\"", &pExpr->span);
+        return SQLITE_ERROR;
+      }
+    }else{
+      pExpr->op = TK_STRING;
+    }
+  }
+  return rc;
+}
+
+/*
+** An SQL user-function registered to do the work of an ATTACH statement. The
+** three arguments to the function come directly from an attach statement:
+**
+**     ATTACH DATABASE x AS y KEY z
+**
+**     SELECT sqlite_attach(x, y, z)
+**
+** If the optional "KEY z" syntax is omitted, an SQL NULL is passed as the
+** third argument.
+*/
+static void attachFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int i;
+  int rc = 0;
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  const char *zName;
+  const char *zFile;
+  Db *aNew;
+  char *zErrDyn = 0;
+  char zErr[128];
+
+  zFile = (const char *)sqlite3_value_text(argv[0]);
+  zName = (const char *)sqlite3_value_text(argv[1]);
+  if( zFile==0 ) zFile = "";
+  if( zName==0 ) zName = "";
+
+  /* Check for the following errors:
+  **
+  **     * Too many attached databases,
+  **     * Transaction currently open
+  **     * Specified database name already being used.
+  */
+  if( db->nDb>=db->aLimit[SQLITE_LIMIT_ATTACHED]+2 ){
+    sqlite3_snprintf(
+      sizeof(zErr), zErr, "too many attached databases - max %d", 
+      db->aLimit[SQLITE_LIMIT_ATTACHED]
+    );
+    goto attach_error;
+  }
+  if( !db->autoCommit ){
+    sqlite3_snprintf(sizeof(zErr), zErr,
+                     "cannot ATTACH database within transaction");
+    goto attach_error;
+  }
+  for(i=0; i<db->nDb; i++){
+    char *z = db->aDb[i].zName;
+    if( z && zName && sqlite3StrICmp(z, zName)==0 ){
+      sqlite3_snprintf(sizeof(zErr), zErr, 
+                       "database %s is already in use", zName);
+      goto attach_error;
+    }
+  }
+
+  /* Allocate the new entry in the db->aDb[] array and initialise the schema
+  ** hash tables.
+  */
+  if( db->aDb==db->aDbStatic ){
+    aNew = sqlite3DbMallocRaw(db, sizeof(db->aDb[0])*3 );
+    if( aNew==0 ) return;
+    memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
+  }else{
+    aNew = sqlite3DbRealloc(db, db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );
+    if( aNew==0 ) return;
+  }
+  db->aDb = aNew;
+  aNew = &db->aDb[db->nDb++];
+  memset(aNew, 0, sizeof(*aNew));
+
+  /* Open the database file. If the btree is successfully opened, use
+  ** it to obtain the database schema. At this point the schema may
+  ** or may not be initialised.
+  */
+  rc = sqlite3BtreeFactory(db, zFile, 0, SQLITE_DEFAULT_CACHE_SIZE,
+                           db->openFlags | SQLITE_OPEN_MAIN_DB,
+                           &aNew->pBt);
+  if( rc==SQLITE_OK ){
+    Pager *pPager;
+    aNew->pSchema = sqlite3SchemaGet(db, aNew->pBt);
+    if( !aNew->pSchema ){
+      rc = SQLITE_NOMEM;
+    }else if( aNew->pSchema->file_format && aNew->pSchema->enc!=ENC(db) ){
+      sqlite3_snprintf(sizeof(zErr), zErr, 
+        "attached databases must use the same text encoding as main database");
+      goto attach_error;
+    }
+    pPager = sqlite3BtreePager(aNew->pBt);
+    sqlite3PagerLockingMode(pPager, db->dfltLockMode);
+    sqlite3PagerJournalMode(pPager, db->dfltJournalMode);
+  }
+  aNew->zName = sqlite3DbStrDup(db, zName);
+  aNew->safety_level = 3;
+
+#if SQLITE_HAS_CODEC
+  {
+    extern int sqlite3CodecAttach(sqlite3*, int, const void*, int);
+    extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
+    int nKey;
+    char *zKey;
+    int t = sqlite3_value_type(argv[2]);
+    switch( t ){
+      case SQLITE_INTEGER:
+      case SQLITE_FLOAT:
+        zErrDyn = sqlite3DbStrDup(db, "Invalid key value");
+        rc = SQLITE_ERROR;
+        break;
+        
+      case SQLITE_TEXT:
+      case SQLITE_BLOB:
+        nKey = sqlite3_value_bytes(argv[2]);
+        zKey = (char *)sqlite3_value_blob(argv[2]);
+        sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
+        break;
+
+      case SQLITE_NULL:
+        /* No key specified.  Use the key from the main database */
+        sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
+        sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
+        break;
+    }
+  }
+#endif
+
+  /* If the file was opened successfully, read the schema for the new database.
+  ** If this fails, or if opening the file failed, then close the file and 
+  ** remove the entry from the db->aDb[] array. i.e. put everything back the way
+  ** we found it.
+  */
+  if( rc==SQLITE_OK ){
+    (void)sqlite3SafetyOn(db);
+    sqlite3BtreeEnterAll(db);
+    rc = sqlite3Init(db, &zErrDyn);
+    sqlite3BtreeLeaveAll(db);
+    (void)sqlite3SafetyOff(db);
+  }
+  if( rc ){
+    int iDb = db->nDb - 1;
+    assert( iDb>=2 );
+    if( db->aDb[iDb].pBt ){
+      sqlite3BtreeClose(db->aDb[iDb].pBt);
+      db->aDb[iDb].pBt = 0;
+      db->aDb[iDb].pSchema = 0;
+    }
+    sqlite3ResetInternalSchema(db, 0);
+    db->nDb = iDb;
+    if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
+      db->mallocFailed = 1;
+      sqlite3_snprintf(sizeof(zErr),zErr, "out of memory");
+    }else{
+      sqlite3_snprintf(sizeof(zErr),zErr, "unable to open database: %s", zFile);
+    }
+    goto attach_error;
+  }
+  
+  return;
+
+attach_error:
+  /* Return an error if we get here */
+  if( zErrDyn ){
+    sqlite3_result_error(context, zErrDyn, -1);
+    sqlite3DbFree(db, zErrDyn);
+  }else{
+    zErr[sizeof(zErr)-1] = 0;
+    sqlite3_result_error(context, zErr, -1);
+  }
+  if( rc ) sqlite3_result_error_code(context, rc);
+}
+
+/*
+** An SQL user-function registered to do the work of an DETACH statement. The
+** three arguments to the function come directly from a detach statement:
+**
+**     DETACH DATABASE x
+**
+**     SELECT sqlite_detach(x)
+*/
+static void detachFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const char *zName = (const char *)sqlite3_value_text(argv[0]);
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  int i;
+  Db *pDb = 0;
+  char zErr[128];
+
+  if( zName==0 ) zName = "";
+  for(i=0; i<db->nDb; i++){
+    pDb = &db->aDb[i];
+    if( pDb->pBt==0 ) continue;
+    if( sqlite3StrICmp(pDb->zName, zName)==0 ) break;
+  }
+
+  if( i>=db->nDb ){
+    sqlite3_snprintf(sizeof(zErr),zErr, "no such database: %s", zName);
+    goto detach_error;
+  }
+  if( i<2 ){
+    sqlite3_snprintf(sizeof(zErr),zErr, "cannot detach database %s", zName);
+    goto detach_error;
+  }
+  if( !db->autoCommit ){
+    sqlite3_snprintf(sizeof(zErr), zErr,
+                     "cannot DETACH database within transaction");
+    goto detach_error;
+  }
+  if( sqlite3BtreeIsInReadTrans(pDb->pBt) ){
+    sqlite3_snprintf(sizeof(zErr),zErr, "database %s is locked", zName);
+    goto detach_error;
+  }
+
+  sqlite3BtreeClose(pDb->pBt);
+  pDb->pBt = 0;
+  pDb->pSchema = 0;
+  sqlite3ResetInternalSchema(db, 0);
+  return;
+
+detach_error:
+  sqlite3_result_error(context, zErr, -1);
+}
+
+/*
+** This procedure generates VDBE code for a single invocation of either the
+** sqlite_detach() or sqlite_attach() SQL user functions.
+*/
+static void codeAttach(
+  Parse *pParse,       /* The parser context */
+  int type,            /* Either SQLITE_ATTACH or SQLITE_DETACH */
+  const char *zFunc,   /* Either "sqlite_attach" or "sqlite_detach */
+  int nFunc,           /* Number of args to pass to zFunc */
+  Expr *pAuthArg,      /* Expression to pass to authorization callback */
+  Expr *pFilename,     /* Name of database file */
+  Expr *pDbname,       /* Name of the database to use internally */
+  Expr *pKey           /* Database key for encryption extension */
+){
+  int rc;
+  NameContext sName;
+  Vdbe *v;
+  FuncDef *pFunc;
+  sqlite3* db = pParse->db;
+  int regArgs;
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  assert( db->mallocFailed || pAuthArg );
+  if( pAuthArg ){
+    char *zAuthArg = sqlite3NameFromToken(db, &pAuthArg->span);
+    if( !zAuthArg ){
+      goto attach_end;
+    }
+    rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0);
+    sqlite3DbFree(db, zAuthArg);
+    if(rc!=SQLITE_OK ){
+      goto attach_end;
+    }
+  }
+#endif /* SQLITE_OMIT_AUTHORIZATION */
+
+  memset(&sName, 0, sizeof(NameContext));
+  sName.pParse = pParse;
+
+  if( 
+      SQLITE_OK!=(rc = resolveAttachExpr(&sName, pFilename)) ||
+      SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) ||
+      SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey))
+  ){
+    pParse->nErr++;
+    goto attach_end;
+  }
+
+  v = sqlite3GetVdbe(pParse);
+  regArgs = sqlite3GetTempRange(pParse, 4);
+  sqlite3ExprCode(pParse, pFilename, regArgs);
+  sqlite3ExprCode(pParse, pDbname, regArgs+1);
+  sqlite3ExprCode(pParse, pKey, regArgs+2);
+
+  assert( v || db->mallocFailed );
+  if( v ){
+    sqlite3VdbeAddOp3(v, OP_Function, 0, regArgs+3-nFunc, regArgs+3);
+    sqlite3VdbeChangeP5(v, nFunc);
+    pFunc = sqlite3FindFunction(db, zFunc, strlen(zFunc), nFunc, SQLITE_UTF8,0);
+    sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF);
+
+    /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
+    ** statement only). For DETACH, set it to false (expire all existing
+    ** statements).
+    */
+    sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH));
+  }
+  
+attach_end:
+  sqlite3ExprDelete(db, pFilename);
+  sqlite3ExprDelete(db, pDbname);
+  sqlite3ExprDelete(db, pKey);
+}
+
+/*
+** Called by the parser to compile a DETACH statement.
+**
+**     DETACH pDbname
+*/
+void sqlite3Detach(Parse *pParse, Expr *pDbname){
+  codeAttach(pParse, SQLITE_DETACH, "sqlite_detach", 1, pDbname, 0, 0, pDbname);
+}
+
+/*
+** Called by the parser to compile an ATTACH statement.
+**
+**     ATTACH p AS pDbname KEY pKey
+*/
+void sqlite3Attach(Parse *pParse, Expr *p, Expr *pDbname, Expr *pKey){
+  codeAttach(pParse, SQLITE_ATTACH, "sqlite_attach", 3, p, p, pDbname, pKey);
+}
+#endif /* SQLITE_OMIT_ATTACH */
+
+/*
+** Register the functions sqlite_attach and sqlite_detach.
+*/
+void sqlite3AttachFunctions(sqlite3 *db){
+#ifndef SQLITE_OMIT_ATTACH
+  static const int enc = SQLITE_UTF8;
+  sqlite3CreateFunc(db, "sqlite_attach", 3, enc, 0, attachFunc, 0, 0);
+  sqlite3CreateFunc(db, "sqlite_detach", 1, enc, 0, detachFunc, 0, 0);
+#endif
+}
+
+/*
+** Initialize a DbFixer structure.  This routine must be called prior
+** to passing the structure to one of the sqliteFixAAAA() routines below.
+**
+** The return value indicates whether or not fixation is required.  TRUE
+** means we do need to fix the database references, FALSE means we do not.
+*/
+int sqlite3FixInit(
+  DbFixer *pFix,      /* The fixer to be initialized */
+  Parse *pParse,      /* Error messages will be written here */
+  int iDb,            /* This is the database that must be used */
+  const char *zType,  /* "view", "trigger", or "index" */
+  const Token *pName  /* Name of the view, trigger, or index */
+){
+  sqlite3 *db;
+
+  if( iDb<0 || iDb==1 ) return 0;
+  db = pParse->db;
+  assert( db->nDb>iDb );
+  pFix->pParse = pParse;
+  pFix->zDb = db->aDb[iDb].zName;
+  pFix->zType = zType;
+  pFix->pName = pName;
+  return 1;
+}
+
+/*
+** The following set of routines walk through the parse tree and assign
+** a specific database to all table references where the database name
+** was left unspecified in the original SQL statement.  The pFix structure
+** must have been initialized by a prior call to sqlite3FixInit().
+**
+** These routines are used to make sure that an index, trigger, or
+** view in one database does not refer to objects in a different database.
+** (Exception: indices, triggers, and views in the TEMP database are
+** allowed to refer to anything.)  If a reference is explicitly made
+** to an object in a different database, an error message is added to
+** pParse->zErrMsg and these routines return non-zero.  If everything
+** checks out, these routines return 0.
+*/
+int sqlite3FixSrcList(
+  DbFixer *pFix,       /* Context of the fixation */
+  SrcList *pList       /* The Source list to check and modify */
+){
+  int i;
+  const char *zDb;
+  struct SrcList_item *pItem;
+
+  if( pList==0 ) return 0;
+  zDb = pFix->zDb;
+  for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
+    if( pItem->zDatabase==0 ){
+      pItem->zDatabase = sqlite3DbStrDup(pFix->pParse->db, zDb);
+    }else if( sqlite3StrICmp(pItem->zDatabase,zDb)!=0 ){
+      sqlite3ErrorMsg(pFix->pParse,
+         "%s %T cannot reference objects in database %s",
+         pFix->zType, pFix->pName, pItem->zDatabase);
+      return 1;
+    }
+#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
+    if( sqlite3FixSelect(pFix, pItem->pSelect) ) return 1;
+    if( sqlite3FixExpr(pFix, pItem->pOn) ) return 1;
+#endif
+  }
+  return 0;
+}
+#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
+int sqlite3FixSelect(
+  DbFixer *pFix,       /* Context of the fixation */
+  Select *pSelect      /* The SELECT statement to be fixed to one database */
+){
+  while( pSelect ){
+    if( sqlite3FixExprList(pFix, pSelect->pEList) ){
+      return 1;
+    }
+    if( sqlite3FixSrcList(pFix, pSelect->pSrc) ){
+      return 1;
+    }
+    if( sqlite3FixExpr(pFix, pSelect->pWhere) ){
+      return 1;
+    }
+    if( sqlite3FixExpr(pFix, pSelect->pHaving) ){
+      return 1;
+    }
+    pSelect = pSelect->pPrior;
+  }
+  return 0;
+}
+int sqlite3FixExpr(
+  DbFixer *pFix,     /* Context of the fixation */
+  Expr *pExpr        /* The expression to be fixed to one database */
+){
+  while( pExpr ){
+    if( sqlite3FixSelect(pFix, pExpr->pSelect) ){
+      return 1;
+    }
+    if( sqlite3FixExprList(pFix, pExpr->pList) ){
+      return 1;
+    }
+    if( sqlite3FixExpr(pFix, pExpr->pRight) ){
+      return 1;
+    }
+    pExpr = pExpr->pLeft;
+  }
+  return 0;
+}
+int sqlite3FixExprList(
+  DbFixer *pFix,     /* Context of the fixation */
+  ExprList *pList    /* The expression to be fixed to one database */
+){
+  int i;
+  struct ExprList_item *pItem;
+  if( pList==0 ) return 0;
+  for(i=0, pItem=pList->a; i<pList->nExpr; i++, pItem++){
+    if( sqlite3FixExpr(pFix, pItem->pExpr) ){
+      return 1;
+    }
+  }
+  return 0;
+}
+#endif
+
+#ifndef SQLITE_OMIT_TRIGGER
+int sqlite3FixTriggerStep(
+  DbFixer *pFix,     /* Context of the fixation */
+  TriggerStep *pStep /* The trigger step be fixed to one database */
+){
+  while( pStep ){
+    if( sqlite3FixSelect(pFix, pStep->pSelect) ){
+      return 1;
+    }
+    if( sqlite3FixExpr(pFix, pStep->pWhere) ){
+      return 1;
+    }
+    if( sqlite3FixExprList(pFix, pStep->pExprList) ){
+      return 1;
+    }
+    pStep = pStep->pNext;
+  }
+  return 0;
+}
+#endif
diff --git a/third_party/sqlite/src/auth.c b/third_party/sqlite/src/auth.c
new file mode 100755
index 0000000..5630c23
--- /dev/null
+++ b/third_party/sqlite/src/auth.c
@@ -0,0 +1,234 @@
+/*
+** 2003 January 11
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code used to implement the sqlite3_set_authorizer()
+** API.  This facility is an optional feature of the library.  Embedded
+** systems that do not need this facility may omit it by recompiling
+** the library with -DSQLITE_OMIT_AUTHORIZATION=1
+**
+** $Id: auth.c,v 1.29 2007/09/18 15:55:07 drh Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** All of the code in this file may be omitted by defining a single
+** macro.
+*/
+#ifndef SQLITE_OMIT_AUTHORIZATION
+
+/*
+** Set or clear the access authorization function.
+**
+** The access authorization function is be called during the compilation
+** phase to verify that the user has read and/or write access permission on
+** various fields of the database.  The first argument to the auth function
+** is a copy of the 3rd argument to this routine.  The second argument
+** to the auth function is one of these constants:
+**
+**       SQLITE_CREATE_INDEX
+**       SQLITE_CREATE_TABLE
+**       SQLITE_CREATE_TEMP_INDEX
+**       SQLITE_CREATE_TEMP_TABLE
+**       SQLITE_CREATE_TEMP_TRIGGER
+**       SQLITE_CREATE_TEMP_VIEW
+**       SQLITE_CREATE_TRIGGER
+**       SQLITE_CREATE_VIEW
+**       SQLITE_DELETE
+**       SQLITE_DROP_INDEX
+**       SQLITE_DROP_TABLE
+**       SQLITE_DROP_TEMP_INDEX
+**       SQLITE_DROP_TEMP_TABLE
+**       SQLITE_DROP_TEMP_TRIGGER
+**       SQLITE_DROP_TEMP_VIEW
+**       SQLITE_DROP_TRIGGER
+**       SQLITE_DROP_VIEW
+**       SQLITE_INSERT
+**       SQLITE_PRAGMA
+**       SQLITE_READ
+**       SQLITE_SELECT
+**       SQLITE_TRANSACTION
+**       SQLITE_UPDATE
+**
+** The third and fourth arguments to the auth function are the name of
+** the table and the column that are being accessed.  The auth function
+** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE.  If
+** SQLITE_OK is returned, it means that access is allowed.  SQLITE_DENY
+** means that the SQL statement will never-run - the sqlite3_exec() call
+** will return with an error.  SQLITE_IGNORE means that the SQL statement
+** should run but attempts to read the specified column will return NULL
+** and attempts to write the column will be ignored.
+**
+** Setting the auth function to NULL disables this hook.  The default
+** setting of the auth function is NULL.
+*/
+int sqlite3_set_authorizer(
+  sqlite3 *db,
+  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
+  void *pArg
+){
+  sqlite3_mutex_enter(db->mutex);
+  db->xAuth = xAuth;
+  db->pAuthArg = pArg;
+  sqlite3ExpirePreparedStatements(db);
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+/*
+** Write an error message into pParse->zErrMsg that explains that the
+** user-supplied authorization function returned an illegal value.
+*/
+static void sqliteAuthBadReturnCode(Parse *pParse, int rc){
+  sqlite3ErrorMsg(pParse, "illegal return value (%d) from the "
+    "authorization function - should be SQLITE_OK, SQLITE_IGNORE, "
+    "or SQLITE_DENY", rc);
+  pParse->rc = SQLITE_ERROR;
+}
+
+/*
+** The pExpr should be a TK_COLUMN expression.  The table referred to
+** is in pTabList or else it is the NEW or OLD table of a trigger.  
+** Check to see if it is OK to read this particular column.
+**
+** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 
+** instruction into a TK_NULL.  If the auth function returns SQLITE_DENY,
+** then generate an error.
+*/
+void sqlite3AuthRead(
+  Parse *pParse,        /* The parser context */
+  Expr *pExpr,          /* The expression to check authorization on */
+  Schema *pSchema,      /* The schema of the expression */
+  SrcList *pTabList     /* All table that pExpr might refer to */
+){
+  sqlite3 *db = pParse->db;
+  int rc;
+  Table *pTab = 0;      /* The table being read */
+  const char *zCol;     /* Name of the column of the table */
+  int iSrc;             /* Index in pTabList->a[] of table being read */
+  const char *zDBase;   /* Name of database being accessed */
+  TriggerStack *pStack; /* The stack of current triggers */
+  int iDb;              /* The index of the database the expression refers to */
+
+  if( db->xAuth==0 ) return;
+  if( pExpr->op!=TK_COLUMN ) return;
+  iDb = sqlite3SchemaToIndex(pParse->db, pSchema);
+  if( iDb<0 ){
+    /* An attempt to read a column out of a subquery or other
+    ** temporary table. */
+    return;
+  }
+  for(iSrc=0; pTabList && iSrc<pTabList->nSrc; iSrc++){
+    if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break;
+  }
+  if( iSrc>=0 && pTabList && iSrc<pTabList->nSrc ){
+    pTab = pTabList->a[iSrc].pTab;
+  }else if( (pStack = pParse->trigStack)!=0 ){
+    /* This must be an attempt to read the NEW or OLD pseudo-tables
+    ** of a trigger.
+    */
+    assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx );
+    pTab = pStack->pTab;
+  }
+  if( pTab==0 ) return;
+  if( pExpr->iColumn>=0 ){
+    assert( pExpr->iColumn<pTab->nCol );
+    zCol = pTab->aCol[pExpr->iColumn].zName;
+  }else if( pTab->iPKey>=0 ){
+    assert( pTab->iPKey<pTab->nCol );
+    zCol = pTab->aCol[pTab->iPKey].zName;
+  }else{
+    zCol = "ROWID";
+  }
+  assert( iDb>=0 && iDb<db->nDb );
+  zDBase = db->aDb[iDb].zName;
+  rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase, 
+                 pParse->zAuthContext);
+  if( rc==SQLITE_IGNORE ){
+    pExpr->op = TK_NULL;
+  }else if( rc==SQLITE_DENY ){
+    if( db->nDb>2 || iDb!=0 ){
+      sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited", 
+         zDBase, pTab->zName, zCol);
+    }else{
+      sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited",pTab->zName,zCol);
+    }
+    pParse->rc = SQLITE_AUTH;
+  }else if( rc!=SQLITE_OK ){
+    sqliteAuthBadReturnCode(pParse, rc);
+  }
+}
+
+/*
+** Do an authorization check using the code and arguments given.  Return
+** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY.  If SQLITE_DENY
+** is returned, then the error count and error message in pParse are
+** modified appropriately.
+*/
+int sqlite3AuthCheck(
+  Parse *pParse,
+  int code,
+  const char *zArg1,
+  const char *zArg2,
+  const char *zArg3
+){
+  sqlite3 *db = pParse->db;
+  int rc;
+
+  /* Don't do any authorization checks if the database is initialising
+  ** or if the parser is being invoked from within sqlite3_declare_vtab.
+  */
+  if( db->init.busy || IN_DECLARE_VTAB ){
+    return SQLITE_OK;
+  }
+
+  if( db->xAuth==0 ){
+    return SQLITE_OK;
+  }
+  rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext);
+  if( rc==SQLITE_DENY ){
+    sqlite3ErrorMsg(pParse, "not authorized");
+    pParse->rc = SQLITE_AUTH;
+  }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
+    rc = SQLITE_DENY;
+    sqliteAuthBadReturnCode(pParse, rc);
+  }
+  return rc;
+}
+
+/*
+** Push an authorization context.  After this routine is called, the
+** zArg3 argument to authorization callbacks will be zContext until
+** popped.  Or if pParse==0, this routine is a no-op.
+*/
+void sqlite3AuthContextPush(
+  Parse *pParse,
+  AuthContext *pContext, 
+  const char *zContext
+){
+  pContext->pParse = pParse;
+  if( pParse ){
+    pContext->zAuthContext = pParse->zAuthContext;
+    pParse->zAuthContext = zContext;
+  }
+}
+
+/*
+** Pop an authorization context that was previously pushed
+** by sqlite3AuthContextPush
+*/
+void sqlite3AuthContextPop(AuthContext *pContext){
+  if( pContext->pParse ){
+    pContext->pParse->zAuthContext = pContext->zAuthContext;
+    pContext->pParse = 0;
+  }
+}
+
+#endif /* SQLITE_OMIT_AUTHORIZATION */
diff --git a/third_party/sqlite/src/bitvec.c b/third_party/sqlite/src/bitvec.c
new file mode 100755
index 0000000..e911315
--- /dev/null
+++ b/third_party/sqlite/src/bitvec.c
@@ -0,0 +1,325 @@
+/*
+** 2008 February 16
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file implements an object that represents a fixed-length
+** bitmap.  Bits are numbered starting with 1.
+**
+** A bitmap is used to record what pages a database file have been
+** journalled during a transaction.  Usually only a few pages are
+** journalled.  So the bitmap is usually sparse and has low cardinality.
+** But sometimes (for example when during a DROP of a large table) most
+** or all of the pages get journalled.  In those cases, the bitmap becomes
+** dense.  The algorithm needs to handle both cases well.
+**
+** The size of the bitmap is fixed when the object is created.
+**
+** All bits are clear when the bitmap is created.  Individual bits
+** may be set or cleared one at a time.
+**
+** Test operations are about 100 times more common that set operations.
+** Clear operations are exceedingly rare.  There are usually between
+** 5 and 500 set operations per Bitvec object, though the number of sets can
+** sometimes grow into tens of thousands or larger.  The size of the
+** Bitvec object is the number of pages in the database file at the
+** start of a transaction, and is thus usually less than a few thousand,
+** but can be as large as 2 billion for a really big database.
+**
+** @(#) $Id: bitvec.c,v 1.6 2008/06/20 14:59:51 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+
+#define BITVEC_SZ        512
+/* Round the union size down to the nearest pointer boundary, since that's how 
+** it will be aligned within the Bitvec struct. */
+#define BITVEC_USIZE     (((BITVEC_SZ-12)/sizeof(Bitvec*))*sizeof(Bitvec*))
+#define BITVEC_NCHAR     BITVEC_USIZE
+#define BITVEC_NBIT      (BITVEC_NCHAR*8)
+#define BITVEC_NINT      (BITVEC_USIZE/4)
+#define BITVEC_MXHASH    (BITVEC_NINT/2)
+#define BITVEC_NPTR      (BITVEC_USIZE/sizeof(Bitvec *))
+
+#define BITVEC_HASH(X)   (((X)*37)%BITVEC_NINT)
+
+/*
+** A bitmap is an instance of the following structure.
+**
+** This bitmap records the existance of zero or more bits
+** with values between 1 and iSize, inclusive.
+**
+** There are three possible representations of the bitmap.
+** If iSize<=BITVEC_NBIT, then Bitvec.u.aBitmap[] is a straight
+** bitmap.  The least significant bit is bit 1.
+**
+** If iSize>BITVEC_NBIT and iDivisor==0 then Bitvec.u.aHash[] is
+** a hash table that will hold up to BITVEC_MXHASH distinct values.
+**
+** Otherwise, the value i is redirected into one of BITVEC_NPTR
+** sub-bitmaps pointed to by Bitvec.u.apSub[].  Each subbitmap
+** handles up to iDivisor separate values of i.  apSub[0] holds
+** values between 1 and iDivisor.  apSub[1] holds values between
+** iDivisor+1 and 2*iDivisor.  apSub[N] holds values between
+** N*iDivisor+1 and (N+1)*iDivisor.  Each subbitmap is normalized
+** to hold deal with values between 1 and iDivisor.
+*/
+struct Bitvec {
+  u32 iSize;      /* Maximum bit index */
+  u32 nSet;       /* Number of bits that are set */
+  u32 iDivisor;   /* Number of bits handled by each apSub[] entry */
+  union {
+    u8 aBitmap[BITVEC_NCHAR];    /* Bitmap representation */
+    u32 aHash[BITVEC_NINT];      /* Hash table representation */
+    Bitvec *apSub[BITVEC_NPTR];  /* Recursive representation */
+  } u;
+};
+
+/*
+** Create a new bitmap object able to handle bits between 0 and iSize,
+** inclusive.  Return a pointer to the new object.  Return NULL if 
+** malloc fails.
+*/
+Bitvec *sqlite3BitvecCreate(u32 iSize){
+  Bitvec *p;
+  assert( sizeof(*p)==BITVEC_SZ );
+  p = sqlite3MallocZero( sizeof(*p) );
+  if( p ){
+    p->iSize = iSize;
+  }
+  return p;
+}
+
+/*
+** Check to see if the i-th bit is set.  Return true or false.
+** If p is NULL (if the bitmap has not been created) or if
+** i is out of range, then return false.
+*/
+int sqlite3BitvecTest(Bitvec *p, u32 i){
+  if( p==0 ) return 0;
+  if( i>p->iSize || i==0 ) return 0;
+  if( p->iSize<=BITVEC_NBIT ){
+    i--;
+    return (p->u.aBitmap[i/8] & (1<<(i&7)))!=0;
+  }
+  if( p->iDivisor>0 ){
+    u32 bin = (i-1)/p->iDivisor;
+    i = (i-1)%p->iDivisor + 1;
+    return sqlite3BitvecTest(p->u.apSub[bin], i);
+  }else{
+    u32 h = BITVEC_HASH(i);
+    while( p->u.aHash[h] ){
+      if( p->u.aHash[h]==i ) return 1;
+      h++;
+      if( h>=BITVEC_NINT ) h = 0;
+    }
+    return 0;
+  }
+}
+
+/*
+** Set the i-th bit.  Return 0 on success and an error code if
+** anything goes wrong.
+*/
+int sqlite3BitvecSet(Bitvec *p, u32 i){
+  u32 h;
+  assert( p!=0 );
+  assert( i>0 );
+  assert( i<=p->iSize );
+  if( p->iSize<=BITVEC_NBIT ){
+    i--;
+    p->u.aBitmap[i/8] |= 1 << (i&7);
+    return SQLITE_OK;
+  }
+  if( p->iDivisor ){
+    u32 bin = (i-1)/p->iDivisor;
+    i = (i-1)%p->iDivisor + 1;
+    if( p->u.apSub[bin]==0 ){
+      sqlite3BeginBenignMalloc();
+      p->u.apSub[bin] = sqlite3BitvecCreate( p->iDivisor );
+      sqlite3EndBenignMalloc();
+      if( p->u.apSub[bin]==0 ) return SQLITE_NOMEM;
+    }
+    return sqlite3BitvecSet(p->u.apSub[bin], i);
+  }
+  h = BITVEC_HASH(i);
+  while( p->u.aHash[h] ){
+    if( p->u.aHash[h]==i ) return SQLITE_OK;
+    h++;
+    if( h==BITVEC_NINT ) h = 0;
+  }
+  p->nSet++;
+  if( p->nSet>=BITVEC_MXHASH ){
+    int j, rc;
+    u32 aiValues[BITVEC_NINT];
+    memcpy(aiValues, p->u.aHash, sizeof(aiValues));
+    memset(p->u.apSub, 0, sizeof(p->u.apSub[0])*BITVEC_NPTR);
+    p->iDivisor = (p->iSize + BITVEC_NPTR - 1)/BITVEC_NPTR;
+    rc = sqlite3BitvecSet(p, i);
+    for(j=0; j<BITVEC_NINT; j++){
+      if( aiValues[j] ) rc |= sqlite3BitvecSet(p, aiValues[j]);
+    }
+    return rc;
+  }
+  p->u.aHash[h] = i;
+  return SQLITE_OK;
+}
+
+/*
+** Clear the i-th bit.  Return 0 on success and an error code if
+** anything goes wrong.
+*/
+void sqlite3BitvecClear(Bitvec *p, u32 i){
+  assert( p!=0 );
+  assert( i>0 );
+  if( p->iSize<=BITVEC_NBIT ){
+    i--;
+    p->u.aBitmap[i/8] &= ~(1 << (i&7));
+  }else if( p->iDivisor ){
+    u32 bin = (i-1)/p->iDivisor;
+    i = (i-1)%p->iDivisor + 1;
+    if( p->u.apSub[bin] ){
+      sqlite3BitvecClear(p->u.apSub[bin], i);
+    }
+  }else{
+    int j;
+    u32 aiValues[BITVEC_NINT];
+    memcpy(aiValues, p->u.aHash, sizeof(aiValues));
+    memset(p->u.aHash, 0, sizeof(p->u.aHash[0])*BITVEC_NINT);
+    p->nSet = 0;
+    for(j=0; j<BITVEC_NINT; j++){
+      if( aiValues[j] && aiValues[j]!=i ){
+        sqlite3BitvecSet(p, aiValues[j]);
+      }
+    }
+  }
+}
+
+/*
+** Destroy a bitmap object.  Reclaim all memory used.
+*/
+void sqlite3BitvecDestroy(Bitvec *p){
+  if( p==0 ) return;
+  if( p->iDivisor ){
+    int i;
+    for(i=0; i<BITVEC_NPTR; i++){
+      sqlite3BitvecDestroy(p->u.apSub[i]);
+    }
+  }
+  sqlite3_free(p);
+}
+
+#ifndef SQLITE_OMIT_BUILTIN_TEST
+/*
+** Let V[] be an array of unsigned characters sufficient to hold
+** up to N bits.  Let I be an integer between 0 and N.  0<=I<N.
+** Then the following macros can be used to set, clear, or test
+** individual bits within V.
+*/
+#define SETBIT(V,I)      V[I>>3] |= (1<<(I&7))
+#define CLEARBIT(V,I)    V[I>>3] &= ~(1<<(I&7))
+#define TESTBIT(V,I)     (V[I>>3]&(1<<(I&7)))!=0
+
+/*
+** This routine runs an extensive test of the Bitvec code.
+**
+** The input is an array of integers that acts as a program
+** to test the Bitvec.  The integers are opcodes followed
+** by 0, 1, or 3 operands, depending on the opcode.  Another
+** opcode follows immediately after the last operand.
+**
+** There are 6 opcodes numbered from 0 through 5.  0 is the
+** "halt" opcode and causes the test to end.
+**
+**    0          Halt and return the number of errors
+**    1 N S X    Set N bits beginning with S and incrementing by X
+**    2 N S X    Clear N bits beginning with S and incrementing by X
+**    3 N        Set N randomly chosen bits
+**    4 N        Clear N randomly chosen bits
+**    5 N S X    Set N bits from S increment X in array only, not in bitvec
+**
+** The opcodes 1 through 4 perform set and clear operations are performed
+** on both a Bitvec object and on a linear array of bits obtained from malloc.
+** Opcode 5 works on the linear array only, not on the Bitvec.
+** Opcode 5 is used to deliberately induce a fault in order to
+** confirm that error detection works.
+**
+** At the conclusion of the test the linear array is compared
+** against the Bitvec object.  If there are any differences,
+** an error is returned.  If they are the same, zero is returned.
+**
+** If a memory allocation error occurs, return -1.
+*/
+int sqlite3BitvecBuiltinTest(int sz, int *aOp){
+  Bitvec *pBitvec = 0;
+  unsigned char *pV = 0;
+  int rc = -1;
+  int i, nx, pc, op;
+
+  /* Allocate the Bitvec to be tested and a linear array of
+  ** bits to act as the reference */
+  pBitvec = sqlite3BitvecCreate( sz );
+  pV = sqlite3_malloc( (sz+7)/8 + 1 );
+  if( pBitvec==0 || pV==0 ) goto bitvec_end;
+  memset(pV, 0, (sz+7)/8 + 1);
+
+  /* Run the program */
+  pc = 0;
+  while( (op = aOp[pc])!=0 ){
+    switch( op ){
+      case 1:
+      case 2:
+      case 5: {
+        nx = 4;
+        i = aOp[pc+2] - 1;
+        aOp[pc+2] += aOp[pc+3];
+        break;
+      }
+      case 3:
+      case 4: 
+      default: {
+        nx = 2;
+        sqlite3_randomness(sizeof(i), &i);
+        break;
+      }
+    }
+    if( (--aOp[pc+1]) > 0 ) nx = 0;
+    pc += nx;
+    i = (i & 0x7fffffff)%sz;
+    if( (op & 1)!=0 ){
+      SETBIT(pV, (i+1));
+      if( op!=5 ){
+        if( sqlite3BitvecSet(pBitvec, i+1) ) goto bitvec_end;
+      }
+    }else{
+      CLEARBIT(pV, (i+1));
+      sqlite3BitvecClear(pBitvec, i+1);
+    }
+  }
+
+  /* Test to make sure the linear array exactly matches the
+  ** Bitvec object.  Start with the assumption that they do
+  ** match (rc==0).  Change rc to non-zero if a discrepancy
+  ** is found.
+  */
+  rc = sqlite3BitvecTest(0,0) + sqlite3BitvecTest(pBitvec, sz+1)
+          + sqlite3BitvecTest(pBitvec, 0);
+  for(i=1; i<=sz; i++){
+    if(  (TESTBIT(pV,i))!=sqlite3BitvecTest(pBitvec,i) ){
+      rc = i;
+      break;
+    }
+  }
+
+  /* Free allocated structure */
+bitvec_end:
+  sqlite3_free(pV);
+  sqlite3BitvecDestroy(pBitvec);
+  return rc;
+}
+#endif /* SQLITE_OMIT_BUILTIN_TEST */
diff --git a/third_party/sqlite/src/btmutex.c b/third_party/sqlite/src/btmutex.c
new file mode 100755
index 0000000..bf63617
--- /dev/null
+++ b/third_party/sqlite/src/btmutex.c
@@ -0,0 +1,317 @@
+/*
+** 2007 August 27
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** $Id: btmutex.c,v 1.10 2008/07/14 19:39:17 drh Exp $
+**
+** This file contains code used to implement mutexes on Btree objects.
+** This code really belongs in btree.c.  But btree.c is getting too
+** big and we want to break it down some.  This packaged seemed like
+** a good breakout.
+*/
+#include "btreeInt.h"
+#if SQLITE_THREADSAFE && !defined(SQLITE_OMIT_SHARED_CACHE)
+
+
+/*
+** Enter a mutex on the given BTree object.
+**
+** If the object is not sharable, then no mutex is ever required
+** and this routine is a no-op.  The underlying mutex is non-recursive.
+** But we keep a reference count in Btree.wantToLock so the behavior
+** of this interface is recursive.
+**
+** To avoid deadlocks, multiple Btrees are locked in the same order
+** by all database connections.  The p->pNext is a list of other
+** Btrees belonging to the same database connection as the p Btree
+** which need to be locked after p.  If we cannot get a lock on
+** p, then first unlock all of the others on p->pNext, then wait
+** for the lock to become available on p, then relock all of the
+** subsequent Btrees that desire a lock.
+*/
+void sqlite3BtreeEnter(Btree *p){
+  Btree *pLater;
+
+  /* Some basic sanity checking on the Btree.  The list of Btrees
+  ** connected by pNext and pPrev should be in sorted order by
+  ** Btree.pBt value. All elements of the list should belong to
+  ** the same connection. Only shared Btrees are on the list. */
+  assert( p->pNext==0 || p->pNext->pBt>p->pBt );
+  assert( p->pPrev==0 || p->pPrev->pBt<p->pBt );
+  assert( p->pNext==0 || p->pNext->db==p->db );
+  assert( p->pPrev==0 || p->pPrev->db==p->db );
+  assert( p->sharable || (p->pNext==0 && p->pPrev==0) );
+
+  /* Check for locking consistency */
+  assert( !p->locked || p->wantToLock>0 );
+  assert( p->sharable || p->wantToLock==0 );
+
+  /* We should already hold a lock on the database connection */
+  assert( sqlite3_mutex_held(p->db->mutex) );
+
+  if( !p->sharable ) return;
+  p->wantToLock++;
+  if( p->locked ) return;
+
+#ifndef SQLITE_MUTEX_NOOP
+  /* In most cases, we should be able to acquire the lock we
+  ** want without having to go throught the ascending lock
+  ** procedure that follows.  Just be sure not to block.
+  */
+  if( sqlite3_mutex_try(p->pBt->mutex)==SQLITE_OK ){
+    p->locked = 1;
+    return;
+  }
+
+  /* To avoid deadlock, first release all locks with a larger
+  ** BtShared address.  Then acquire our lock.  Then reacquire
+  ** the other BtShared locks that we used to hold in ascending
+  ** order.
+  */
+  for(pLater=p->pNext; pLater; pLater=pLater->pNext){
+    assert( pLater->sharable );
+    assert( pLater->pNext==0 || pLater->pNext->pBt>pLater->pBt );
+    assert( !pLater->locked || pLater->wantToLock>0 );
+    if( pLater->locked ){
+      sqlite3_mutex_leave(pLater->pBt->mutex);
+      pLater->locked = 0;
+    }
+  }
+  sqlite3_mutex_enter(p->pBt->mutex);
+  p->locked = 1;
+  for(pLater=p->pNext; pLater; pLater=pLater->pNext){
+    if( pLater->wantToLock ){
+      sqlite3_mutex_enter(pLater->pBt->mutex);
+      pLater->locked = 1;
+    }
+  }
+#endif /* SQLITE_MUTEX_NOOP */
+}
+
+/*
+** Exit the recursive mutex on a Btree.
+*/
+void sqlite3BtreeLeave(Btree *p){
+  if( p->sharable ){
+    assert( p->wantToLock>0 );
+    p->wantToLock--;
+    if( p->wantToLock==0 ){
+      assert( p->locked );
+      sqlite3_mutex_leave(p->pBt->mutex);
+      p->locked = 0;
+    }
+  }
+}
+
+#ifndef NDEBUG
+/*
+** Return true if the BtShared mutex is held on the btree.  
+**
+** This routine makes no determination one why or another if the
+** database connection mutex is held.
+**
+** This routine is used only from within assert() statements.
+*/
+int sqlite3BtreeHoldsMutex(Btree *p){
+  return (p->sharable==0 ||
+             (p->locked && p->wantToLock && sqlite3_mutex_held(p->pBt->mutex)));
+}
+#endif
+
+
+#ifndef SQLITE_OMIT_INCRBLOB
+/*
+** Enter and leave a mutex on a Btree given a cursor owned by that
+** Btree.  These entry points are used by incremental I/O and can be
+** omitted if that module is not used.
+*/
+void sqlite3BtreeEnterCursor(BtCursor *pCur){
+  sqlite3BtreeEnter(pCur->pBtree);
+}
+void sqlite3BtreeLeaveCursor(BtCursor *pCur){
+  sqlite3BtreeLeave(pCur->pBtree);
+}
+#endif /* SQLITE_OMIT_INCRBLOB */
+
+
+/*
+** Enter the mutex on every Btree associated with a database
+** connection.  This is needed (for example) prior to parsing
+** a statement since we will be comparing table and column names
+** against all schemas and we do not want those schemas being
+** reset out from under us.
+**
+** There is a corresponding leave-all procedures.
+**
+** Enter the mutexes in accending order by BtShared pointer address
+** to avoid the possibility of deadlock when two threads with
+** two or more btrees in common both try to lock all their btrees
+** at the same instant.
+*/
+void sqlite3BtreeEnterAll(sqlite3 *db){
+  int i;
+  Btree *p, *pLater;
+  assert( sqlite3_mutex_held(db->mutex) );
+  for(i=0; i<db->nDb; i++){
+    p = db->aDb[i].pBt;
+    if( p && p->sharable ){
+      p->wantToLock++;
+      if( !p->locked ){
+        assert( p->wantToLock==1 );
+        while( p->pPrev ) p = p->pPrev;
+        while( p->locked && p->pNext ) p = p->pNext;
+        for(pLater = p->pNext; pLater; pLater=pLater->pNext){
+          if( pLater->locked ){
+            sqlite3_mutex_leave(pLater->pBt->mutex);
+            pLater->locked = 0;
+          }
+        }
+        while( p ){
+          sqlite3_mutex_enter(p->pBt->mutex);
+          p->locked++;
+          p = p->pNext;
+        }
+      }
+    }
+  }
+}
+void sqlite3BtreeLeaveAll(sqlite3 *db){
+  int i;
+  Btree *p;
+  assert( sqlite3_mutex_held(db->mutex) );
+  for(i=0; i<db->nDb; i++){
+    p = db->aDb[i].pBt;
+    if( p && p->sharable ){
+      assert( p->wantToLock>0 );
+      p->wantToLock--;
+      if( p->wantToLock==0 ){
+        assert( p->locked );
+        sqlite3_mutex_leave(p->pBt->mutex);
+        p->locked = 0;
+      }
+    }
+  }
+}
+
+#ifndef NDEBUG
+/*
+** Return true if the current thread holds the database connection
+** mutex and all required BtShared mutexes.
+**
+** This routine is used inside assert() statements only.
+*/
+int sqlite3BtreeHoldsAllMutexes(sqlite3 *db){
+  int i;
+  if( !sqlite3_mutex_held(db->mutex) ){
+    return 0;
+  }
+  for(i=0; i<db->nDb; i++){
+    Btree *p;
+    p = db->aDb[i].pBt;
+    if( p && p->sharable &&
+         (p->wantToLock==0 || !sqlite3_mutex_held(p->pBt->mutex)) ){
+      return 0;
+    }
+  }
+  return 1;
+}
+#endif /* NDEBUG */
+
+/*
+** Add a new Btree pointer to a BtreeMutexArray. 
+** if the pointer can possibly be shared with
+** another database connection.
+**
+** The pointers are kept in sorted order by pBtree->pBt.  That
+** way when we go to enter all the mutexes, we can enter them
+** in order without every having to backup and retry and without
+** worrying about deadlock.
+**
+** The number of shared btrees will always be small (usually 0 or 1)
+** so an insertion sort is an adequate algorithm here.
+*/
+void sqlite3BtreeMutexArrayInsert(BtreeMutexArray *pArray, Btree *pBtree){
+  int i, j;
+  BtShared *pBt;
+  if( pBtree==0 || pBtree->sharable==0 ) return;
+#ifndef NDEBUG
+  {
+    for(i=0; i<pArray->nMutex; i++){
+      assert( pArray->aBtree[i]!=pBtree );
+    }
+  }
+#endif
+  assert( pArray->nMutex>=0 );
+  assert( pArray->nMutex<sizeof(pArray->aBtree)/sizeof(pArray->aBtree[0])-1 );
+  pBt = pBtree->pBt;
+  for(i=0; i<pArray->nMutex; i++){
+    assert( pArray->aBtree[i]!=pBtree );
+    if( pArray->aBtree[i]->pBt>pBt ){
+      for(j=pArray->nMutex; j>i; j--){
+        pArray->aBtree[j] = pArray->aBtree[j-1];
+      }
+      pArray->aBtree[i] = pBtree;
+      pArray->nMutex++;
+      return;
+    }
+  }
+  pArray->aBtree[pArray->nMutex++] = pBtree;
+}
+
+/*
+** Enter the mutex of every btree in the array.  This routine is
+** called at the beginning of sqlite3VdbeExec().  The mutexes are
+** exited at the end of the same function.
+*/
+void sqlite3BtreeMutexArrayEnter(BtreeMutexArray *pArray){
+  int i;
+  for(i=0; i<pArray->nMutex; i++){
+    Btree *p = pArray->aBtree[i];
+    /* Some basic sanity checking */
+    assert( i==0 || pArray->aBtree[i-1]->pBt<p->pBt );
+    assert( !p->locked || p->wantToLock>0 );
+
+    /* We should already hold a lock on the database connection */
+    assert( sqlite3_mutex_held(p->db->mutex) );
+
+    p->wantToLock++;
+    if( !p->locked && p->sharable ){
+      sqlite3_mutex_enter(p->pBt->mutex);
+      p->locked = 1;
+    }
+  }
+}
+
+/*
+** Leave the mutex of every btree in the group.
+*/
+void sqlite3BtreeMutexArrayLeave(BtreeMutexArray *pArray){
+  int i;
+  for(i=0; i<pArray->nMutex; i++){
+    Btree *p = pArray->aBtree[i];
+    /* Some basic sanity checking */
+    assert( i==0 || pArray->aBtree[i-1]->pBt<p->pBt );
+    assert( p->locked || !p->sharable );
+    assert( p->wantToLock>0 );
+
+    /* We should already hold a lock on the database connection */
+    assert( sqlite3_mutex_held(p->db->mutex) );
+
+    p->wantToLock--;
+    if( p->wantToLock==0 && p->locked ){
+      sqlite3_mutex_leave(p->pBt->mutex);
+      p->locked = 0;
+    }
+  }
+}
+
+
+#endif  /* SQLITE_THREADSAFE && !SQLITE_OMIT_SHARED_CACHE */
diff --git a/third_party/sqlite/src/btree.c b/third_party/sqlite/src/btree.c
new file mode 100755
index 0000000..dc71523
--- /dev/null
+++ b/third_party/sqlite/src/btree.c
@@ -0,0 +1,7401 @@
+/*
+** 2004 April 6
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** $Id: btree.c,v 1.495 2008/08/02 17:36:46 danielk1977 Exp $
+**
+** This file implements a external (disk-based) database using BTrees.
+** See the header comment on "btreeInt.h" for additional information.
+** Including a description of file format and an overview of operation.
+*/
+#include "btreeInt.h"
+
+/*
+** The header string that appears at the beginning of every
+** SQLite database.
+*/
+static const char zMagicHeader[] = SQLITE_FILE_HEADER;
+
+/*
+** The header string that appears at the beginning of a SQLite
+** database which has been poisoned.
+*/
+static const char zPoisonHeader[] = "SQLite poison 3";
+
+/*
+** Set this global variable to 1 to enable tracing using the TRACE
+** macro.
+*/
+#if 0
+int sqlite3BtreeTrace=0;  /* True to enable tracing */
+# define TRACE(X)  if(sqlite3BtreeTrace){printf X;fflush(stdout);}
+#else
+# define TRACE(X)
+#endif
+
+
+
+#ifndef SQLITE_OMIT_SHARED_CACHE
+/*
+** A flag to indicate whether or not shared cache is enabled.  Also,
+** a list of BtShared objects that are eligible for participation
+** in shared cache.  The variables have file scope during normal builds,
+** but the test harness needs to access these variables so we make them
+** global for test builds.
+*/
+#ifdef SQLITE_TEST
+BtShared *sqlite3SharedCacheList = 0;
+int sqlite3SharedCacheEnabled = 0;
+#else
+static BtShared *sqlite3SharedCacheList = 0;
+static int sqlite3SharedCacheEnabled = 0;
+#endif
+#endif /* SQLITE_OMIT_SHARED_CACHE */
+
+#ifndef SQLITE_OMIT_SHARED_CACHE
+/*
+** Enable or disable the shared pager and schema features.
+**
+** This routine has no effect on existing database connections.
+** The shared cache setting effects only future calls to
+** sqlite3_open(), sqlite3_open16(), or sqlite3_open_v2().
+*/
+int sqlite3_enable_shared_cache(int enable){
+  sqlite3SharedCacheEnabled = enable;
+  return SQLITE_OK;
+}
+#endif
+
+
+/*
+** Forward declaration
+*/
+static int checkReadLocks(Btree*, Pgno, BtCursor*, i64);
+
+
+#ifdef SQLITE_OMIT_SHARED_CACHE
+  /*
+  ** The functions queryTableLock(), lockTable() and unlockAllTables()
+  ** manipulate entries in the BtShared.pLock linked list used to store
+  ** shared-cache table level locks. If the library is compiled with the
+  ** shared-cache feature disabled, then there is only ever one user
+  ** of each BtShared structure and so this locking is not necessary. 
+  ** So define the lock related functions as no-ops.
+  */
+  #define queryTableLock(a,b,c) SQLITE_OK
+  #define lockTable(a,b,c) SQLITE_OK
+  #define unlockAllTables(a)
+#endif
+
+#ifndef SQLITE_OMIT_SHARED_CACHE
+/*
+** Query to see if btree handle p may obtain a lock of type eLock 
+** (READ_LOCK or WRITE_LOCK) on the table with root-page iTab. Return
+** SQLITE_OK if the lock may be obtained (by calling lockTable()), or
+** SQLITE_LOCKED if not.
+*/
+static int queryTableLock(Btree *p, Pgno iTab, u8 eLock){
+  BtShared *pBt = p->pBt;
+  BtLock *pIter;
+
+  assert( sqlite3BtreeHoldsMutex(p) );
+  assert( eLock==READ_LOCK || eLock==WRITE_LOCK );
+  assert( p->db!=0 );
+  
+  /* This is a no-op if the shared-cache is not enabled */
+  if( !p->sharable ){
+    return SQLITE_OK;
+  }
+
+  /* If some other connection is holding an exclusive lock, the
+  ** requested lock may not be obtained.
+  */
+  if( pBt->pExclusive && pBt->pExclusive!=p ){
+    return SQLITE_LOCKED;
+  }
+
+  /* This (along with lockTable()) is where the ReadUncommitted flag is
+  ** dealt with. If the caller is querying for a read-lock and the flag is
+  ** set, it is unconditionally granted - even if there are write-locks
+  ** on the table. If a write-lock is requested, the ReadUncommitted flag
+  ** is not considered.
+  **
+  ** In function lockTable(), if a read-lock is demanded and the 
+  ** ReadUncommitted flag is set, no entry is added to the locks list 
+  ** (BtShared.pLock).
+  **
+  ** To summarize: If the ReadUncommitted flag is set, then read cursors do
+  ** not create or respect table locks. The locking procedure for a 
+  ** write-cursor does not change.
+  */
+  if( 
+    0==(p->db->flags&SQLITE_ReadUncommitted) || 
+    eLock==WRITE_LOCK ||
+    iTab==MASTER_ROOT
+  ){
+    for(pIter=pBt->pLock; pIter; pIter=pIter->pNext){
+      if( pIter->pBtree!=p && pIter->iTable==iTab && 
+          (pIter->eLock!=eLock || eLock!=READ_LOCK) ){
+        return SQLITE_LOCKED;
+      }
+    }
+  }
+  return SQLITE_OK;
+}
+#endif /* !SQLITE_OMIT_SHARED_CACHE */
+
+#ifndef SQLITE_OMIT_SHARED_CACHE
+/*
+** Add a lock on the table with root-page iTable to the shared-btree used
+** by Btree handle p. Parameter eLock must be either READ_LOCK or 
+** WRITE_LOCK.
+**
+** SQLITE_OK is returned if the lock is added successfully. SQLITE_BUSY and
+** SQLITE_NOMEM may also be returned.
+*/
+static int lockTable(Btree *p, Pgno iTable, u8 eLock){
+  BtShared *pBt = p->pBt;
+  BtLock *pLock = 0;
+  BtLock *pIter;
+
+  assert( sqlite3BtreeHoldsMutex(p) );
+  assert( eLock==READ_LOCK || eLock==WRITE_LOCK );
+  assert( p->db!=0 );
+
+  /* This is a no-op if the shared-cache is not enabled */
+  if( !p->sharable ){
+    return SQLITE_OK;
+  }
+
+  assert( SQLITE_OK==queryTableLock(p, iTable, eLock) );
+
+  /* If the read-uncommitted flag is set and a read-lock is requested,
+  ** return early without adding an entry to the BtShared.pLock list. See
+  ** comment in function queryTableLock() for more info on handling 
+  ** the ReadUncommitted flag.
+  */
+  if( 
+    (p->db->flags&SQLITE_ReadUncommitted) && 
+    (eLock==READ_LOCK) &&
+    iTable!=MASTER_ROOT
+  ){
+    return SQLITE_OK;
+  }
+
+  /* First search the list for an existing lock on this table. */
+  for(pIter=pBt->pLock; pIter; pIter=pIter->pNext){
+    if( pIter->iTable==iTable && pIter->pBtree==p ){
+      pLock = pIter;
+      break;
+    }
+  }
+
+  /* If the above search did not find a BtLock struct associating Btree p
+  ** with table iTable, allocate one and link it into the list.
+  */
+  if( !pLock ){
+    pLock = (BtLock *)sqlite3MallocZero(sizeof(BtLock));
+    if( !pLock ){
+      return SQLITE_NOMEM;
+    }
+    pLock->iTable = iTable;
+    pLock->pBtree = p;
+    pLock->pNext = pBt->pLock;
+    pBt->pLock = pLock;
+  }
+
+  /* Set the BtLock.eLock variable to the maximum of the current lock
+  ** and the requested lock. This means if a write-lock was already held
+  ** and a read-lock requested, we don't incorrectly downgrade the lock.
+  */
+  assert( WRITE_LOCK>READ_LOCK );
+  if( eLock>pLock->eLock ){
+    pLock->eLock = eLock;
+  }
+
+  return SQLITE_OK;
+}
+#endif /* !SQLITE_OMIT_SHARED_CACHE */
+
+#ifndef SQLITE_OMIT_SHARED_CACHE
+/*
+** Release all the table locks (locks obtained via calls to the lockTable()
+** procedure) held by Btree handle p.
+*/
+static void unlockAllTables(Btree *p){
+  BtShared *pBt = p->pBt;
+  BtLock **ppIter = &pBt->pLock;
+
+  assert( sqlite3BtreeHoldsMutex(p) );
+  assert( p->sharable || 0==*ppIter );
+
+  while( *ppIter ){
+    BtLock *pLock = *ppIter;
+    assert( pBt->pExclusive==0 || pBt->pExclusive==pLock->pBtree );
+    if( pLock->pBtree==p ){
+      *ppIter = pLock->pNext;
+      sqlite3_free(pLock);
+    }else{
+      ppIter = &pLock->pNext;
+    }
+  }
+
+  if( pBt->pExclusive==p ){
+    pBt->pExclusive = 0;
+  }
+}
+#endif /* SQLITE_OMIT_SHARED_CACHE */
+
+static void releasePage(MemPage *pPage);  /* Forward reference */
+
+/*
+** Verify that the cursor holds a mutex on the BtShared
+*/
+#ifndef NDEBUG
+static int cursorHoldsMutex(BtCursor *p){
+  return sqlite3_mutex_held(p->pBt->mutex);
+}
+#endif
+
+
+#ifndef SQLITE_OMIT_INCRBLOB
+/*
+** Invalidate the overflow page-list cache for cursor pCur, if any.
+*/
+static void invalidateOverflowCache(BtCursor *pCur){
+  assert( cursorHoldsMutex(pCur) );
+  sqlite3_free(pCur->aOverflow);
+  pCur->aOverflow = 0;
+}
+
+/*
+** Invalidate the overflow page-list cache for all cursors opened
+** on the shared btree structure pBt.
+*/
+static void invalidateAllOverflowCache(BtShared *pBt){
+  BtCursor *p;
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  for(p=pBt->pCursor; p; p=p->pNext){
+    invalidateOverflowCache(p);
+  }
+}
+#else
+  #define invalidateOverflowCache(x)
+  #define invalidateAllOverflowCache(x)
+#endif
+
+/*
+** Save the current cursor position in the variables BtCursor.nKey 
+** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
+*/
+static int saveCursorPosition(BtCursor *pCur){
+  int rc;
+
+  assert( CURSOR_VALID==pCur->eState );
+  assert( 0==pCur->pKey );
+  assert( cursorHoldsMutex(pCur) );
+
+  rc = sqlite3BtreeKeySize(pCur, &pCur->nKey);
+
+  /* If this is an intKey table, then the above call to BtreeKeySize()
+  ** stores the integer key in pCur->nKey. In this case this value is
+  ** all that is required. Otherwise, if pCur is not open on an intKey
+  ** table, then malloc space for and store the pCur->nKey bytes of key 
+  ** data.
+  */
+  if( rc==SQLITE_OK && 0==pCur->pPage->intKey){
+    void *pKey = sqlite3Malloc(pCur->nKey);
+    if( pKey ){
+      rc = sqlite3BtreeKey(pCur, 0, pCur->nKey, pKey);
+      if( rc==SQLITE_OK ){
+        pCur->pKey = pKey;
+      }else{
+        sqlite3_free(pKey);
+      }
+    }else{
+      rc = SQLITE_NOMEM;
+    }
+  }
+  assert( !pCur->pPage->intKey || !pCur->pKey );
+
+  if( rc==SQLITE_OK ){
+    releasePage(pCur->pPage);
+    pCur->pPage = 0;
+    pCur->eState = CURSOR_REQUIRESEEK;
+  }
+
+  invalidateOverflowCache(pCur);
+  return rc;
+}
+
+/*
+** Save the positions of all cursors except pExcept open on the table 
+** with root-page iRoot. Usually, this is called just before cursor
+** pExcept is used to modify the table (BtreeDelete() or BtreeInsert()).
+*/
+static int saveAllCursors(BtShared *pBt, Pgno iRoot, BtCursor *pExcept){
+  BtCursor *p;
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  assert( pExcept==0 || pExcept->pBt==pBt );
+  for(p=pBt->pCursor; p; p=p->pNext){
+    if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) && 
+        p->eState==CURSOR_VALID ){
+      int rc = saveCursorPosition(p);
+      if( SQLITE_OK!=rc ){
+        return rc;
+      }
+    }
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Clear the current cursor position.
+*/
+static void clearCursorPosition(BtCursor *pCur){
+  assert( cursorHoldsMutex(pCur) );
+  sqlite3_free(pCur->pKey);
+  pCur->pKey = 0;
+  pCur->eState = CURSOR_INVALID;
+}
+
+/*
+** Restore the cursor to the position it was in (or as close to as possible)
+** when saveCursorPosition() was called. Note that this call deletes the 
+** saved position info stored by saveCursorPosition(), so there can be
+** at most one effective restoreCursorPosition() call after each 
+** saveCursorPosition().
+*/
+int sqlite3BtreeRestoreCursorPosition(BtCursor *pCur){
+  int rc;
+  assert( cursorHoldsMutex(pCur) );
+  assert( pCur->eState>=CURSOR_REQUIRESEEK );
+  if( pCur->eState==CURSOR_FAULT ){
+    return pCur->skip;
+  }
+  pCur->eState = CURSOR_INVALID;
+  rc = sqlite3BtreeMoveto(pCur, pCur->pKey, 0, pCur->nKey, 0, &pCur->skip);
+  if( rc==SQLITE_OK ){
+    sqlite3_free(pCur->pKey);
+    pCur->pKey = 0;
+    assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_INVALID );
+  }
+  return rc;
+}
+
+#define restoreCursorPosition(p) \
+  (p->eState>=CURSOR_REQUIRESEEK ? \
+         sqlite3BtreeRestoreCursorPosition(p) : \
+         SQLITE_OK)
+
+/*
+** Determine whether or not a cursor has moved from the position it
+** was last placed at.  Cursor can move when the row they are pointing
+** at is deleted out from under them.
+**
+** This routine returns an error code if something goes wrong.  The
+** integer *pHasMoved is set to one if the cursor has moved and 0 if not.
+*/
+int sqlite3BtreeCursorHasMoved(BtCursor *pCur, int *pHasMoved){
+  int rc;
+
+  rc = restoreCursorPosition(pCur);
+  if( rc ){
+    *pHasMoved = 1;
+    return rc;
+  }
+  if( pCur->eState!=CURSOR_VALID || pCur->skip!=0 ){
+    *pHasMoved = 1;
+  }else{
+    *pHasMoved = 0;
+  }
+  return SQLITE_OK;
+}
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+/*
+** Given a page number of a regular database page, return the page
+** number for the pointer-map page that contains the entry for the
+** input page number.
+*/
+static Pgno ptrmapPageno(BtShared *pBt, Pgno pgno){
+  int nPagesPerMapPage, iPtrMap, ret;
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  nPagesPerMapPage = (pBt->usableSize/5)+1;
+  iPtrMap = (pgno-2)/nPagesPerMapPage;
+  ret = (iPtrMap*nPagesPerMapPage) + 2; 
+  if( ret==PENDING_BYTE_PAGE(pBt) ){
+    ret++;
+  }
+  return ret;
+}
+
+/*
+** Write an entry into the pointer map.
+**
+** This routine updates the pointer map entry for page number 'key'
+** so that it maps to type 'eType' and parent page number 'pgno'.
+** An error code is returned if something goes wrong, otherwise SQLITE_OK.
+*/
+static int ptrmapPut(BtShared *pBt, Pgno key, u8 eType, Pgno parent){
+  DbPage *pDbPage;  /* The pointer map page */
+  u8 *pPtrmap;      /* The pointer map data */
+  Pgno iPtrmap;     /* The pointer map page number */
+  int offset;       /* Offset in pointer map page */
+  int rc;
+
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  /* The master-journal page number must never be used as a pointer map page */
+  assert( 0==PTRMAP_ISPAGE(pBt, PENDING_BYTE_PAGE(pBt)) );
+
+  assert( pBt->autoVacuum );
+  if( key==0 ){
+    return SQLITE_CORRUPT_BKPT;
+  }
+  iPtrmap = PTRMAP_PAGENO(pBt, key);
+  rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+  offset = PTRMAP_PTROFFSET(iPtrmap, key);
+  pPtrmap = (u8 *)sqlite3PagerGetData(pDbPage);
+
+  if( eType!=pPtrmap[offset] || get4byte(&pPtrmap[offset+1])!=parent ){
+    TRACE(("PTRMAP_UPDATE: %d->(%d,%d)\n", key, eType, parent));
+    rc = sqlite3PagerWrite(pDbPage);
+    if( rc==SQLITE_OK ){
+      pPtrmap[offset] = eType;
+      put4byte(&pPtrmap[offset+1], parent);
+    }
+  }
+
+  sqlite3PagerUnref(pDbPage);
+  return rc;
+}
+
+/*
+** Read an entry from the pointer map.
+**
+** This routine retrieves the pointer map entry for page 'key', writing
+** the type and parent page number to *pEType and *pPgno respectively.
+** An error code is returned if something goes wrong, otherwise SQLITE_OK.
+*/
+static int ptrmapGet(BtShared *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
+  DbPage *pDbPage;   /* The pointer map page */
+  int iPtrmap;       /* Pointer map page index */
+  u8 *pPtrmap;       /* Pointer map page data */
+  int offset;        /* Offset of entry in pointer map */
+  int rc;
+
+  assert( sqlite3_mutex_held(pBt->mutex) );
+
+  iPtrmap = PTRMAP_PAGENO(pBt, key);
+  rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage);
+  if( rc!=0 ){
+    return rc;
+  }
+  pPtrmap = (u8 *)sqlite3PagerGetData(pDbPage);
+
+  offset = PTRMAP_PTROFFSET(iPtrmap, key);
+  assert( pEType!=0 );
+  *pEType = pPtrmap[offset];
+  if( pPgno ) *pPgno = get4byte(&pPtrmap[offset+1]);
+
+  sqlite3PagerUnref(pDbPage);
+  if( *pEType<1 || *pEType>5 ) return SQLITE_CORRUPT_BKPT;
+  return SQLITE_OK;
+}
+
+#else /* if defined SQLITE_OMIT_AUTOVACUUM */
+  #define ptrmapPut(w,x,y,z) SQLITE_OK
+  #define ptrmapGet(w,x,y,z) SQLITE_OK
+  #define ptrmapPutOvfl(y,z) SQLITE_OK
+#endif
+
+/*
+** Given a btree page and a cell index (0 means the first cell on
+** the page, 1 means the second cell, and so forth) return a pointer
+** to the cell content.
+**
+** This routine works only for pages that do not contain overflow cells.
+*/
+#define findCell(P,I) \
+  ((P)->aData + ((P)->maskPage & get2byte(&(P)->aData[(P)->cellOffset+2*(I)])))
+
+/*
+** This a more complex version of findCell() that works for
+** pages that do contain overflow cells.  See insert
+*/
+static u8 *findOverflowCell(MemPage *pPage, int iCell){
+  int i;
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  for(i=pPage->nOverflow-1; i>=0; i--){
+    int k;
+    struct _OvflCell *pOvfl;
+    pOvfl = &pPage->aOvfl[i];
+    k = pOvfl->idx;
+    if( k<=iCell ){
+      if( k==iCell ){
+        return pOvfl->pCell;
+      }
+      iCell--;
+    }
+  }
+  return findCell(pPage, iCell);
+}
+
+/*
+** Parse a cell content block and fill in the CellInfo structure.  There
+** are two versions of this function.  sqlite3BtreeParseCell() takes a 
+** cell index as the second argument and sqlite3BtreeParseCellPtr() 
+** takes a pointer to the body of the cell as its second argument.
+**
+** Within this file, the parseCell() macro can be called instead of
+** sqlite3BtreeParseCellPtr(). Using some compilers, this will be faster.
+*/
+void sqlite3BtreeParseCellPtr(
+  MemPage *pPage,         /* Page containing the cell */
+  u8 *pCell,              /* Pointer to the cell text. */
+  CellInfo *pInfo         /* Fill in this structure */
+){
+  int n;                  /* Number bytes in cell content header */
+  u32 nPayload;           /* Number of bytes of cell payload */
+
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+
+  pInfo->pCell = pCell;
+  assert( pPage->leaf==0 || pPage->leaf==1 );
+  n = pPage->childPtrSize;
+  assert( n==4-4*pPage->leaf );
+  if( pPage->intKey ){
+    if( pPage->hasData ){
+      n += getVarint32(&pCell[n], nPayload);
+    }else{
+      nPayload = 0;
+    }
+    n += getVarint(&pCell[n], (u64*)&pInfo->nKey);
+    pInfo->nData = nPayload;
+  }else{
+    pInfo->nData = 0;
+    n += getVarint32(&pCell[n], nPayload);
+    pInfo->nKey = nPayload;
+  }
+  pInfo->nPayload = nPayload;
+  pInfo->nHeader = n;
+  if( likely(nPayload<=pPage->maxLocal) ){
+    /* This is the (easy) common case where the entire payload fits
+    ** on the local page.  No overflow is required.
+    */
+    int nSize;          /* Total size of cell content in bytes */
+    nSize = nPayload + n;
+    pInfo->nLocal = nPayload;
+    pInfo->iOverflow = 0;
+    if( (nSize & ~3)==0 ){
+      nSize = 4;        /* Minimum cell size is 4 */
+    }
+    pInfo->nSize = nSize;
+  }else{
+    /* If the payload will not fit completely on the local page, we have
+    ** to decide how much to store locally and how much to spill onto
+    ** overflow pages.  The strategy is to minimize the amount of unused
+    ** space on overflow pages while keeping the amount of local storage
+    ** in between minLocal and maxLocal.
+    **
+    ** Warning:  changing the way overflow payload is distributed in any
+    ** way will result in an incompatible file format.
+    */
+    int minLocal;  /* Minimum amount of payload held locally */
+    int maxLocal;  /* Maximum amount of payload held locally */
+    int surplus;   /* Overflow payload available for local storage */
+
+    minLocal = pPage->minLocal;
+    maxLocal = pPage->maxLocal;
+    surplus = minLocal + (nPayload - minLocal)%(pPage->pBt->usableSize - 4);
+    if( surplus <= maxLocal ){
+      pInfo->nLocal = surplus;
+    }else{
+      pInfo->nLocal = minLocal;
+    }
+    pInfo->iOverflow = pInfo->nLocal + n;
+    pInfo->nSize = pInfo->iOverflow + 4;
+  }
+}
+#define parseCell(pPage, iCell, pInfo) \
+  sqlite3BtreeParseCellPtr((pPage), findCell((pPage), (iCell)), (pInfo))
+void sqlite3BtreeParseCell(
+  MemPage *pPage,         /* Page containing the cell */
+  int iCell,              /* The cell index.  First cell is 0 */
+  CellInfo *pInfo         /* Fill in this structure */
+){
+  parseCell(pPage, iCell, pInfo);
+}
+
+/*
+** Compute the total number of bytes that a Cell needs in the cell
+** data area of the btree-page.  The return number includes the cell
+** data header and the local payload, but not any overflow page or
+** the space used by the cell pointer.
+*/
+#ifndef NDEBUG
+static u16 cellSize(MemPage *pPage, int iCell){
+  CellInfo info;
+  sqlite3BtreeParseCell(pPage, iCell, &info);
+  return info.nSize;
+}
+#endif
+static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
+  CellInfo info;
+  sqlite3BtreeParseCellPtr(pPage, pCell, &info);
+  return info.nSize;
+}
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+/*
+** If the cell pCell, part of page pPage contains a pointer
+** to an overflow page, insert an entry into the pointer-map
+** for the overflow page.
+*/
+static int ptrmapPutOvflPtr(MemPage *pPage, u8 *pCell){
+  CellInfo info;
+  assert( pCell!=0 );
+  sqlite3BtreeParseCellPtr(pPage, pCell, &info);
+  assert( (info.nData+(pPage->intKey?0:info.nKey))==info.nPayload );
+  if( (info.nData+(pPage->intKey?0:info.nKey))>info.nLocal ){
+    Pgno ovfl = get4byte(&pCell[info.iOverflow]);
+    return ptrmapPut(pPage->pBt, ovfl, PTRMAP_OVERFLOW1, pPage->pgno);
+  }
+  return SQLITE_OK;
+}
+/*
+** If the cell with index iCell on page pPage contains a pointer
+** to an overflow page, insert an entry into the pointer-map
+** for the overflow page.
+*/
+static int ptrmapPutOvfl(MemPage *pPage, int iCell){
+  u8 *pCell;
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  pCell = findOverflowCell(pPage, iCell);
+  return ptrmapPutOvflPtr(pPage, pCell);
+}
+#endif
+
+
+/*
+** Defragment the page given.  All Cells are moved to the
+** end of the page and all free space is collected into one
+** big FreeBlk that occurs in between the header and cell
+** pointer array and the cell content area.
+*/
+static void defragmentPage(MemPage *pPage){
+  int i;                     /* Loop counter */
+  int pc;                    /* Address of a i-th cell */
+  int addr;                  /* Offset of first byte after cell pointer array */
+  int hdr;                   /* Offset to the page header */
+  int size;                  /* Size of a cell */
+  int usableSize;            /* Number of usable bytes on a page */
+  int cellOffset;            /* Offset to the cell pointer array */
+  int brk;                   /* Offset to the cell content area */
+  int nCell;                 /* Number of cells on the page */
+  unsigned char *data;       /* The page data */
+  unsigned char *temp;       /* Temp area for cell content */
+
+  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
+  assert( pPage->pBt!=0 );
+  assert( pPage->pBt->usableSize <= SQLITE_MAX_PAGE_SIZE );
+  assert( pPage->nOverflow==0 );
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  temp = sqlite3PagerTempSpace(pPage->pBt->pPager);
+  data = pPage->aData;
+  hdr = pPage->hdrOffset;
+  cellOffset = pPage->cellOffset;
+  nCell = pPage->nCell;
+  assert( nCell==get2byte(&data[hdr+3]) );
+  usableSize = pPage->pBt->usableSize;
+  brk = get2byte(&data[hdr+5]);
+  memcpy(&temp[brk], &data[brk], usableSize - brk);
+  brk = usableSize;
+  for(i=0; i<nCell; i++){
+    u8 *pAddr;     /* The i-th cell pointer */
+    pAddr = &data[cellOffset + i*2];
+    pc = get2byte(pAddr);
+    assert( pc<pPage->pBt->usableSize );
+    size = cellSizePtr(pPage, &temp[pc]);
+    brk -= size;
+    memcpy(&data[brk], &temp[pc], size);
+    put2byte(pAddr, brk);
+  }
+  assert( brk>=cellOffset+2*nCell );
+  put2byte(&data[hdr+5], brk);
+  data[hdr+1] = 0;
+  data[hdr+2] = 0;
+  data[hdr+7] = 0;
+  addr = cellOffset+2*nCell;
+  memset(&data[addr], 0, brk-addr);
+}
+
+/*
+** Allocate nByte bytes of space on a page.
+**
+** Return the index into pPage->aData[] of the first byte of
+** the new allocation.  The caller guarantees that there is enough
+** space.  This routine will never fail.
+**
+** If the page contains nBytes of free space but does not contain
+** nBytes of contiguous free space, then this routine automatically
+** calls defragementPage() to consolidate all free space before 
+** allocating the new chunk.
+*/
+static int allocateSpace(MemPage *pPage, int nByte){
+  int addr, pc, hdr;
+  int size;
+  int nFrag;
+  int top;
+  int nCell;
+  int cellOffset;
+  unsigned char *data;
+  
+  data = pPage->aData;
+  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
+  assert( pPage->pBt );
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  assert( nByte>=0 );  /* Minimum cell size is 4 */
+  assert( pPage->nFree>=nByte );
+  assert( pPage->nOverflow==0 );
+  pPage->nFree -= nByte;
+  hdr = pPage->hdrOffset;
+
+  nFrag = data[hdr+7];
+  if( nFrag<60 ){
+    /* Search the freelist looking for a slot big enough to satisfy the
+    ** space request. */
+    addr = hdr+1;
+    while( (pc = get2byte(&data[addr]))>0 ){
+      size = get2byte(&data[pc+2]);
+      if( size>=nByte ){
+        if( size<nByte+4 ){
+          memcpy(&data[addr], &data[pc], 2);
+          data[hdr+7] = nFrag + size - nByte;
+          return pc;
+        }else{
+          put2byte(&data[pc+2], size-nByte);
+          return pc + size - nByte;
+        }
+      }
+      addr = pc;
+    }
+  }
+
+  /* Allocate memory from the gap in between the cell pointer array
+  ** and the cell content area.
+  */
+  top = get2byte(&data[hdr+5]);
+  nCell = get2byte(&data[hdr+3]);
+  cellOffset = pPage->cellOffset;
+  if( nFrag>=60 || cellOffset + 2*nCell > top - nByte ){
+    defragmentPage(pPage);
+    top = get2byte(&data[hdr+5]);
+  }
+  top -= nByte;
+  assert( cellOffset + 2*nCell <= top );
+  put2byte(&data[hdr+5], top);
+  return top;
+}
+
+/*
+** Return a section of the pPage->aData to the freelist.
+** The first byte of the new free block is pPage->aDisk[start]
+** and the size of the block is "size" bytes.
+**
+** Most of the effort here is involved in coalesing adjacent
+** free blocks into a single big free block.
+*/
+static void freeSpace(MemPage *pPage, int start, int size){
+  int addr, pbegin, hdr;
+  unsigned char *data = pPage->aData;
+
+  assert( pPage->pBt!=0 );
+  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
+  assert( start>=pPage->hdrOffset+6+(pPage->leaf?0:4) );
+  assert( (start + size)<=pPage->pBt->usableSize );
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  assert( size>=0 );   /* Minimum cell size is 4 */
+
+#ifdef SQLITE_SECURE_DELETE
+  /* Overwrite deleted information with zeros when the SECURE_DELETE 
+  ** option is enabled at compile-time */
+  memset(&data[start], 0, size);
+#endif
+
+  /* Add the space back into the linked list of freeblocks */
+  hdr = pPage->hdrOffset;
+  addr = hdr + 1;
+  while( (pbegin = get2byte(&data[addr]))<start && pbegin>0 ){
+    assert( pbegin<=pPage->pBt->usableSize-4 );
+    assert( pbegin>addr );
+    addr = pbegin;
+  }
+  assert( pbegin<=pPage->pBt->usableSize-4 );
+  assert( pbegin>addr || pbegin==0 );
+  put2byte(&data[addr], start);
+  put2byte(&data[start], pbegin);
+  put2byte(&data[start+2], size);
+  pPage->nFree += size;
+
+  /* Coalesce adjacent free blocks */
+  addr = pPage->hdrOffset + 1;
+  while( (pbegin = get2byte(&data[addr]))>0 ){
+    int pnext, psize;
+    assert( pbegin>addr );
+    assert( pbegin<=pPage->pBt->usableSize-4 );
+    pnext = get2byte(&data[pbegin]);
+    psize = get2byte(&data[pbegin+2]);
+    if( pbegin + psize + 3 >= pnext && pnext>0 ){
+      int frag = pnext - (pbegin+psize);
+      assert( frag<=data[pPage->hdrOffset+7] );
+      data[pPage->hdrOffset+7] -= frag;
+      put2byte(&data[pbegin], get2byte(&data[pnext]));
+      put2byte(&data[pbegin+2], pnext+get2byte(&data[pnext+2])-pbegin);
+    }else{
+      addr = pbegin;
+    }
+  }
+
+  /* If the cell content area begins with a freeblock, remove it. */
+  if( data[hdr+1]==data[hdr+5] && data[hdr+2]==data[hdr+6] ){
+    int top;
+    pbegin = get2byte(&data[hdr+1]);
+    memcpy(&data[hdr+1], &data[pbegin], 2);
+    top = get2byte(&data[hdr+5]);
+    put2byte(&data[hdr+5], top + get2byte(&data[pbegin+2]));
+  }
+}
+
+/*
+** Decode the flags byte (the first byte of the header) for a page
+** and initialize fields of the MemPage structure accordingly.
+**
+** Only the following combinations are supported.  Anything different
+** indicates a corrupt database files:
+**
+**         PTF_ZERODATA
+**         PTF_ZERODATA | PTF_LEAF
+**         PTF_LEAFDATA | PTF_INTKEY
+**         PTF_LEAFDATA | PTF_INTKEY | PTF_LEAF
+*/
+static int decodeFlags(MemPage *pPage, int flagByte){
+  BtShared *pBt;     /* A copy of pPage->pBt */
+
+  assert( pPage->hdrOffset==(pPage->pgno==1 ? 100 : 0) );
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  pPage->leaf = flagByte>>3;  assert( PTF_LEAF == 1<<3 );
+  flagByte &= ~PTF_LEAF;
+  pPage->childPtrSize = 4-4*pPage->leaf;
+  pBt = pPage->pBt;
+  if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){
+    pPage->intKey = 1;
+    pPage->hasData = pPage->leaf;
+    pPage->maxLocal = pBt->maxLeaf;
+    pPage->minLocal = pBt->minLeaf;
+  }else if( flagByte==PTF_ZERODATA ){
+    pPage->intKey = 0;
+    pPage->hasData = 0;
+    pPage->maxLocal = pBt->maxLocal;
+    pPage->minLocal = pBt->minLocal;
+  }else{
+    return SQLITE_CORRUPT_BKPT;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Initialize the auxiliary information for a disk block.
+**
+** The pParent parameter must be a pointer to the MemPage which
+** is the parent of the page being initialized.  The root of a
+** BTree has no parent and so for that page, pParent==NULL.
+**
+** Return SQLITE_OK on success.  If we see that the page does
+** not contain a well-formed database page, then return 
+** SQLITE_CORRUPT.  Note that a return of SQLITE_OK does not
+** guarantee that the page is well-formed.  It only shows that
+** we failed to detect any corruption.
+*/
+int sqlite3BtreeInitPage(
+  MemPage *pPage,        /* The page to be initialized */
+  MemPage *pParent       /* The parent.  Might be NULL */
+){
+  int pc;            /* Address of a freeblock within pPage->aData[] */
+  int hdr;           /* Offset to beginning of page header */
+  u8 *data;          /* Equal to pPage->aData */
+  BtShared *pBt;        /* The main btree structure */
+  int usableSize;    /* Amount of usable space on each page */
+  int cellOffset;    /* Offset from start of page to first cell pointer */
+  int nFree;         /* Number of unused bytes on the page */
+  int top;           /* First byte of the cell content area */
+
+  pBt = pPage->pBt;
+  assert( pBt!=0 );
+  assert( pParent==0 || pParent->pBt==pBt );
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  assert( pPage->pgno==sqlite3PagerPagenumber(pPage->pDbPage) );
+  assert( pPage == sqlite3PagerGetExtra(pPage->pDbPage) );
+  assert( pPage->aData == sqlite3PagerGetData(pPage->pDbPage) );
+  if( pPage->pParent!=pParent && (pPage->pParent!=0 || pPage->isInit) ){
+    /* The parent page should never change unless the file is corrupt */
+    return SQLITE_CORRUPT_BKPT;
+  }
+  if( pPage->isInit ) return SQLITE_OK;
+  if( pPage->pParent==0 && pParent!=0 ){
+    pPage->pParent = pParent;
+    sqlite3PagerRef(pParent->pDbPage);
+  }
+  hdr = pPage->hdrOffset;
+  data = pPage->aData;
+  if( decodeFlags(pPage, data[hdr]) ) return SQLITE_CORRUPT_BKPT;
+  assert( pBt->pageSize>=512 && pBt->pageSize<=32768 );
+  pPage->maskPage = pBt->pageSize - 1;
+  pPage->nOverflow = 0;
+  pPage->idxShift = 0;
+  usableSize = pBt->usableSize;
+  pPage->cellOffset = cellOffset = hdr + 12 - 4*pPage->leaf;
+  top = get2byte(&data[hdr+5]);
+  pPage->nCell = get2byte(&data[hdr+3]);
+  if( pPage->nCell>MX_CELL(pBt) ){
+    /* To many cells for a single page.  The page must be corrupt */
+    return SQLITE_CORRUPT_BKPT;
+  }
+  if( pPage->nCell==0 && pParent!=0 && pParent->pgno!=1 ){
+    /* All pages must have at least one cell, except for root pages */
+    return SQLITE_CORRUPT_BKPT;
+  }
+
+  /* Compute the total free space on the page */
+  pc = get2byte(&data[hdr+1]);
+  nFree = data[hdr+7] + top - (cellOffset + 2*pPage->nCell);
+  while( pc>0 ){
+    int next, size;
+    if( pc>usableSize-4 ){
+      /* Free block is off the page */
+      return SQLITE_CORRUPT_BKPT; 
+    }
+    next = get2byte(&data[pc]);
+    size = get2byte(&data[pc+2]);
+    if( next>0 && next<=pc+size+3 ){
+      /* Free blocks must be in accending order */
+      return SQLITE_CORRUPT_BKPT; 
+    }
+    nFree += size;
+    pc = next;
+  }
+  pPage->nFree = nFree;
+  if( nFree>=usableSize ){
+    /* Free space cannot exceed total page size */
+    return SQLITE_CORRUPT_BKPT; 
+  }
+
+#if 0
+  /* Check that all the offsets in the cell offset array are within range. 
+  ** 
+  ** Omitting this consistency check and using the pPage->maskPage mask
+  ** to prevent overrunning the page buffer in findCell() results in a
+  ** 2.5% performance gain.
+  */
+  {
+    u8 *pOff;        /* Iterator used to check all cell offsets are in range */
+    u8 *pEnd;        /* Pointer to end of cell offset array */
+    u8 mask;         /* Mask of bits that must be zero in MSB of cell offsets */
+    mask = ~(((u8)(pBt->pageSize>>8))-1);
+    pEnd = &data[cellOffset + pPage->nCell*2];
+    for(pOff=&data[cellOffset]; pOff!=pEnd && !((*pOff)&mask); pOff+=2);
+    if( pOff!=pEnd ){
+      return SQLITE_CORRUPT_BKPT;
+    }
+  }
+#endif
+
+  pPage->isInit = 1;
+  return SQLITE_OK;
+}
+
+/*
+** Set up a raw page so that it looks like a database page holding
+** no entries.
+*/
+static void zeroPage(MemPage *pPage, int flags){
+  unsigned char *data = pPage->aData;
+  BtShared *pBt = pPage->pBt;
+  int hdr = pPage->hdrOffset;
+  int first;
+
+  assert( sqlite3PagerPagenumber(pPage->pDbPage)==pPage->pgno );
+  assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
+  assert( sqlite3PagerGetData(pPage->pDbPage) == data );
+  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  /*memset(&data[hdr], 0, pBt->usableSize - hdr);*/
+  data[hdr] = flags;
+  first = hdr + 8 + 4*((flags&PTF_LEAF)==0);
+  memset(&data[hdr+1], 0, 4);
+  data[hdr+7] = 0;
+  put2byte(&data[hdr+5], pBt->usableSize);
+  pPage->nFree = pBt->usableSize - first;
+  decodeFlags(pPage, flags);
+  pPage->hdrOffset = hdr;
+  pPage->cellOffset = first;
+  pPage->nOverflow = 0;
+  assert( pBt->pageSize>=512 && pBt->pageSize<=32768 );
+  pPage->maskPage = pBt->pageSize - 1;
+  pPage->idxShift = 0;
+  pPage->nCell = 0;
+  pPage->isInit = 1;
+}
+
+/*
+** Get a page from the pager.  Initialize the MemPage.pBt and
+** MemPage.aData elements if needed.
+**
+** If the noContent flag is set, it means that we do not care about
+** the content of the page at this time.  So do not go to the disk
+** to fetch the content.  Just fill in the content with zeros for now.
+** If in the future we call sqlite3PagerWrite() on this page, that
+** means we have started to be concerned about content and the disk
+** read should occur at that point.
+*/
+int sqlite3BtreeGetPage(
+  BtShared *pBt,       /* The btree */
+  Pgno pgno,           /* Number of the page to fetch */
+  MemPage **ppPage,    /* Return the page in this parameter */
+  int noContent        /* Do not load page content if true */
+){
+  int rc;
+  MemPage *pPage;
+  DbPage *pDbPage;
+
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  rc = sqlite3PagerAcquire(pBt->pPager, pgno, (DbPage**)&pDbPage, noContent);
+  if( rc ) return rc;
+  pPage = (MemPage *)sqlite3PagerGetExtra(pDbPage);
+  pPage->aData = sqlite3PagerGetData(pDbPage);
+  pPage->pDbPage = pDbPage;
+  pPage->pBt = pBt;
+  pPage->pgno = pgno;
+  pPage->hdrOffset = pPage->pgno==1 ? 100 : 0;
+  *ppPage = pPage;
+  return SQLITE_OK;
+}
+
+/*
+** Get a page from the pager and initialize it.  This routine
+** is just a convenience wrapper around separate calls to
+** sqlite3BtreeGetPage() and sqlite3BtreeInitPage().
+*/
+static int getAndInitPage(
+  BtShared *pBt,          /* The database file */
+  Pgno pgno,           /* Number of the page to get */
+  MemPage **ppPage,    /* Write the page pointer here */
+  MemPage *pParent     /* Parent of the page */
+){
+  int rc;
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  if( pgno==0 ){
+    return SQLITE_CORRUPT_BKPT; 
+  }
+  rc = sqlite3BtreeGetPage(pBt, pgno, ppPage, 0);
+  if( rc==SQLITE_OK && (*ppPage)->isInit==0 ){
+    rc = sqlite3BtreeInitPage(*ppPage, pParent);
+    if( rc!=SQLITE_OK ){
+      releasePage(*ppPage);
+      *ppPage = 0;
+    }
+  }
+  return rc;
+}
+
+/*
+** Release a MemPage.  This should be called once for each prior
+** call to sqlite3BtreeGetPage.
+*/
+static void releasePage(MemPage *pPage){
+  if( pPage ){
+    assert( pPage->aData );
+    assert( pPage->pBt );
+    assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
+    assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
+    assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+    sqlite3PagerUnref(pPage->pDbPage);
+  }
+}
+
+/*
+** This routine is called when the reference count for a page
+** reaches zero.  We need to unref the pParent pointer when that
+** happens.
+*/
+static void pageDestructor(DbPage *pData, int pageSize){
+  MemPage *pPage;
+  assert( (pageSize & 7)==0 );
+  pPage = (MemPage *)sqlite3PagerGetExtra(pData);
+  assert( pPage->isInit==0 || sqlite3_mutex_held(pPage->pBt->mutex) );
+  if( pPage->pParent ){
+    MemPage *pParent = pPage->pParent;
+    assert( pParent->pBt==pPage->pBt );
+    pPage->pParent = 0;
+    releasePage(pParent);
+  }
+  pPage->isInit = 0;
+}
+
+/*
+** During a rollback, when the pager reloads information into the cache
+** so that the cache is restored to its original state at the start of
+** the transaction, for each page restored this routine is called.
+**
+** This routine needs to reset the extra data section at the end of the
+** page to agree with the restored data.
+*/
+static void pageReinit(DbPage *pData, int pageSize){
+  MemPage *pPage;
+  assert( (pageSize & 7)==0 );
+  pPage = (MemPage *)sqlite3PagerGetExtra(pData);
+  if( pPage->isInit ){
+    assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+    pPage->isInit = 0;
+    sqlite3BtreeInitPage(pPage, pPage->pParent);
+  }
+}
+
+/*
+** Invoke the busy handler for a btree.
+*/
+static int sqlite3BtreeInvokeBusyHandler(void *pArg, int n){
+  BtShared *pBt = (BtShared*)pArg;
+  assert( pBt->db );
+  assert( sqlite3_mutex_held(pBt->db->mutex) );
+  return sqlite3InvokeBusyHandler(&pBt->db->busyHandler);
+}
+
+/*
+** Open a database file.
+** 
+** zFilename is the name of the database file.  If zFilename is NULL
+** a new database with a random name is created.  This randomly named
+** database file will be deleted when sqlite3BtreeClose() is called.
+** If zFilename is ":memory:" then an in-memory database is created
+** that is automatically destroyed when it is closed.
+*/
+int sqlite3BtreeOpen(
+  const char *zFilename,  /* Name of the file containing the BTree database */
+  sqlite3 *db,            /* Associated database handle */
+  Btree **ppBtree,        /* Pointer to new Btree object written here */
+  int flags,              /* Options */
+  int vfsFlags            /* Flags passed through to sqlite3_vfs.xOpen() */
+){
+  sqlite3_vfs *pVfs;      /* The VFS to use for this btree */
+  BtShared *pBt = 0;      /* Shared part of btree structure */
+  Btree *p;               /* Handle to return */
+  int rc = SQLITE_OK;
+  int nReserve;
+  unsigned char zDbHeader[100];
+
+  /* Set the variable isMemdb to true for an in-memory database, or 
+  ** false for a file-based database. This symbol is only required if
+  ** either of the shared-data or autovacuum features are compiled 
+  ** into the library.
+  */
+#if !defined(SQLITE_OMIT_SHARED_CACHE) || !defined(SQLITE_OMIT_AUTOVACUUM)
+  #ifdef SQLITE_OMIT_MEMORYDB
+    const int isMemdb = 0;
+  #else
+    const int isMemdb = zFilename && !strcmp(zFilename, ":memory:");
+  #endif
+#endif
+
+  assert( db!=0 );
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  pVfs = db->pVfs;
+  p = sqlite3MallocZero(sizeof(Btree));
+  if( !p ){
+    return SQLITE_NOMEM;
+  }
+  p->inTrans = TRANS_NONE;
+  p->db = db;
+
+#if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)
+  /*
+  ** If this Btree is a candidate for shared cache, try to find an
+  ** existing BtShared object that we can share with
+  */
+  if( isMemdb==0
+   && (db->flags & SQLITE_Vtab)==0
+   && zFilename && zFilename[0]
+  ){
+    if( sqlite3SharedCacheEnabled ){
+      int nFullPathname = pVfs->mxPathname+1;
+      char *zFullPathname = sqlite3Malloc(nFullPathname);
+      sqlite3_mutex *mutexShared;
+      p->sharable = 1;
+      db->flags |= SQLITE_SharedCache;
+      if( !zFullPathname ){
+        sqlite3_free(p);
+        return SQLITE_NOMEM;
+      }
+      sqlite3OsFullPathname(pVfs, zFilename, nFullPathname, zFullPathname);
+      mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+      sqlite3_mutex_enter(mutexShared);
+      for(pBt=sqlite3SharedCacheList; pBt; pBt=pBt->pNext){
+        assert( pBt->nRef>0 );
+        if( 0==strcmp(zFullPathname, sqlite3PagerFilename(pBt->pPager))
+                 && sqlite3PagerVfs(pBt->pPager)==pVfs ){
+          p->pBt = pBt;
+          pBt->nRef++;
+          break;
+        }
+      }
+      sqlite3_mutex_leave(mutexShared);
+      sqlite3_free(zFullPathname);
+    }
+#ifdef SQLITE_DEBUG
+    else{
+      /* In debug mode, we mark all persistent databases as sharable
+      ** even when they are not.  This exercises the locking code and
+      ** gives more opportunity for asserts(sqlite3_mutex_held())
+      ** statements to find locking problems.
+      */
+      p->sharable = 1;
+    }
+#endif
+  }
+#endif
+  if( pBt==0 ){
+    /*
+    ** The following asserts make sure that structures used by the btree are
+    ** the right size.  This is to guard against size changes that result
+    ** when compiling on a different architecture.
+    */
+    assert( sizeof(i64)==8 || sizeof(i64)==4 );
+    assert( sizeof(u64)==8 || sizeof(u64)==4 );
+    assert( sizeof(u32)==4 );
+    assert( sizeof(u16)==2 );
+    assert( sizeof(Pgno)==4 );
+  
+    pBt = sqlite3MallocZero( sizeof(*pBt) );
+    if( pBt==0 ){
+      rc = SQLITE_NOMEM;
+      goto btree_open_out;
+    }
+    pBt->busyHdr.xFunc = sqlite3BtreeInvokeBusyHandler;
+    pBt->busyHdr.pArg = pBt;
+    rc = sqlite3PagerOpen(pVfs, &pBt->pPager, zFilename,
+                          EXTRA_SIZE, flags, vfsFlags);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3PagerReadFileheader(pBt->pPager,sizeof(zDbHeader),zDbHeader);
+    }
+    if( rc!=SQLITE_OK ){
+      goto btree_open_out;
+    }
+    sqlite3PagerSetBusyhandler(pBt->pPager, &pBt->busyHdr);
+    p->pBt = pBt;
+  
+    sqlite3PagerSetDestructor(pBt->pPager, pageDestructor);
+    sqlite3PagerSetReiniter(pBt->pPager, pageReinit);
+    pBt->pCursor = 0;
+    pBt->pPage1 = 0;
+    pBt->readOnly = sqlite3PagerIsreadonly(pBt->pPager);
+    pBt->pageSize = get2byte(&zDbHeader[16]);
+    if( pBt->pageSize<512 || pBt->pageSize>SQLITE_MAX_PAGE_SIZE
+         || ((pBt->pageSize-1)&pBt->pageSize)!=0 ){
+      pBt->pageSize = 0;
+      sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+      /* If the magic name ":memory:" will create an in-memory database, then
+      ** leave the autoVacuum mode at 0 (do not auto-vacuum), even if
+      ** SQLITE_DEFAULT_AUTOVACUUM is true. On the other hand, if
+      ** SQLITE_OMIT_MEMORYDB has been defined, then ":memory:" is just a
+      ** regular file-name. In this case the auto-vacuum applies as per normal.
+      */
+      if( zFilename && !isMemdb ){
+        pBt->autoVacuum = (SQLITE_DEFAULT_AUTOVACUUM ? 1 : 0);
+        pBt->incrVacuum = (SQLITE_DEFAULT_AUTOVACUUM==2 ? 1 : 0);
+      }
+#endif
+      nReserve = 0;
+    }else{
+      nReserve = zDbHeader[20];
+      pBt->pageSizeFixed = 1;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+      pBt->autoVacuum = (get4byte(&zDbHeader[36 + 4*4])?1:0);
+      pBt->incrVacuum = (get4byte(&zDbHeader[36 + 7*4])?1:0);
+#endif
+    }
+    pBt->usableSize = pBt->pageSize - nReserve;
+    assert( (pBt->pageSize & 7)==0 );  /* 8-byte alignment of pageSize */
+    sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize);
+   
+#if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)
+    /* Add the new BtShared object to the linked list sharable BtShareds.
+    */
+    if( p->sharable ){
+      sqlite3_mutex *mutexShared;
+      pBt->nRef = 1;
+      mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+      if( SQLITE_THREADSAFE && sqlite3Config.bCoreMutex ){
+        pBt->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_FAST);
+        if( pBt->mutex==0 ){
+          rc = SQLITE_NOMEM;
+          db->mallocFailed = 0;
+          goto btree_open_out;
+        }
+      }
+      sqlite3_mutex_enter(mutexShared);
+      pBt->pNext = sqlite3SharedCacheList;
+      sqlite3SharedCacheList = pBt;
+      sqlite3_mutex_leave(mutexShared);
+    }
+#endif
+  }
+
+#if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)
+  /* If the new Btree uses a sharable pBtShared, then link the new
+  ** Btree into the list of all sharable Btrees for the same connection.
+  ** The list is kept in ascending order by pBt address.
+  */
+  if( p->sharable ){
+    int i;
+    Btree *pSib;
+    for(i=0; i<db->nDb; i++){
+      if( (pSib = db->aDb[i].pBt)!=0 && pSib->sharable ){
+        while( pSib->pPrev ){ pSib = pSib->pPrev; }
+        if( p->pBt<pSib->pBt ){
+          p->pNext = pSib;
+          p->pPrev = 0;
+          pSib->pPrev = p;
+        }else{
+          while( pSib->pNext && pSib->pNext->pBt<p->pBt ){
+            pSib = pSib->pNext;
+          }
+          p->pNext = pSib->pNext;
+          p->pPrev = pSib;
+          if( p->pNext ){
+            p->pNext->pPrev = p;
+          }
+          pSib->pNext = p;
+        }
+        break;
+      }
+    }
+  }
+#endif
+  *ppBtree = p;
+
+btree_open_out:
+  if( rc!=SQLITE_OK ){
+    if( pBt && pBt->pPager ){
+      sqlite3PagerClose(pBt->pPager);
+    }
+    sqlite3_free(pBt);
+    sqlite3_free(p);
+    *ppBtree = 0;
+  }
+  return rc;
+}
+
+/*
+** Decrement the BtShared.nRef counter.  When it reaches zero,
+** remove the BtShared structure from the sharing list.  Return
+** true if the BtShared.nRef counter reaches zero and return
+** false if it is still positive.
+*/
+static int removeFromSharingList(BtShared *pBt){
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  sqlite3_mutex *pMaster;
+  BtShared *pList;
+  int removed = 0;
+
+  assert( sqlite3_mutex_notheld(pBt->mutex) );
+  pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+  sqlite3_mutex_enter(pMaster);
+  pBt->nRef--;
+  if( pBt->nRef<=0 ){
+    if( sqlite3SharedCacheList==pBt ){
+      sqlite3SharedCacheList = pBt->pNext;
+    }else{
+      pList = sqlite3SharedCacheList;
+      while( ALWAYS(pList) && pList->pNext!=pBt ){
+        pList=pList->pNext;
+      }
+      if( ALWAYS(pList) ){
+        pList->pNext = pBt->pNext;
+      }
+    }
+    if( SQLITE_THREADSAFE ){
+      sqlite3_mutex_free(pBt->mutex);
+    }
+    removed = 1;
+  }
+  sqlite3_mutex_leave(pMaster);
+  return removed;
+#else
+  return 1;
+#endif
+}
+
+/*
+** Make sure pBt->pTmpSpace points to an allocation of 
+** MX_CELL_SIZE(pBt) bytes.
+*/
+static void allocateTempSpace(BtShared *pBt){
+  if( !pBt->pTmpSpace ){
+    pBt->pTmpSpace = sqlite3PageMalloc( pBt->pageSize );
+  }
+}
+
+/*
+** Free the pBt->pTmpSpace allocation
+*/
+static void freeTempSpace(BtShared *pBt){
+  sqlite3PageFree( pBt->pTmpSpace);
+  pBt->pTmpSpace = 0;
+}
+
+/*
+** Close an open database and invalidate all cursors.
+*/
+int sqlite3BtreeClose(Btree *p){
+  BtShared *pBt = p->pBt;
+  BtCursor *pCur;
+
+  /* Close all cursors opened via this handle.  */
+  assert( sqlite3_mutex_held(p->db->mutex) );
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+  pCur = pBt->pCursor;
+  while( pCur ){
+    BtCursor *pTmp = pCur;
+    pCur = pCur->pNext;
+    if( pTmp->pBtree==p ){
+      sqlite3BtreeCloseCursor(pTmp);
+    }
+  }
+
+  /* Rollback any active transaction and free the handle structure.
+  ** The call to sqlite3BtreeRollback() drops any table-locks held by
+  ** this handle.
+  */
+  sqlite3BtreeRollback(p);
+  sqlite3BtreeLeave(p);
+
+  /* If there are still other outstanding references to the shared-btree
+  ** structure, return now. The remainder of this procedure cleans 
+  ** up the shared-btree.
+  */
+  assert( p->wantToLock==0 && p->locked==0 );
+  if( !p->sharable || removeFromSharingList(pBt) ){
+    /* The pBt is no longer on the sharing list, so we can access
+    ** it without having to hold the mutex.
+    **
+    ** Clean out and delete the BtShared object.
+    */
+    assert( !pBt->pCursor );
+    sqlite3PagerClose(pBt->pPager);
+    if( pBt->xFreeSchema && pBt->pSchema ){
+      pBt->xFreeSchema(pBt->pSchema);
+    }
+    sqlite3_free(pBt->pSchema);
+    freeTempSpace(pBt);
+    sqlite3_free(pBt);
+  }
+
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  assert( p->wantToLock==0 );
+  assert( p->locked==0 );
+  if( p->pPrev ) p->pPrev->pNext = p->pNext;
+  if( p->pNext ) p->pNext->pPrev = p->pPrev;
+#endif
+
+  sqlite3_free(p);
+  return SQLITE_OK;
+}
+
+/*
+** Change the limit on the number of pages allowed in the cache.
+**
+** The maximum number of cache pages is set to the absolute
+** value of mxPage.  If mxPage is negative, the pager will
+** operate asynchronously - it will not stop to do fsync()s
+** to insure data is written to the disk surface before
+** continuing.  Transactions still work if synchronous is off,
+** and the database cannot be corrupted if this program
+** crashes.  But if the operating system crashes or there is
+** an abrupt power failure when synchronous is off, the database
+** could be left in an inconsistent and unrecoverable state.
+** Synchronous is on by default so database corruption is not
+** normally a worry.
+*/
+int sqlite3BtreeSetCacheSize(Btree *p, int mxPage){
+  BtShared *pBt = p->pBt;
+  assert( sqlite3_mutex_held(p->db->mutex) );
+  sqlite3BtreeEnter(p);
+  sqlite3PagerSetCachesize(pBt->pPager, mxPage);
+  sqlite3BtreeLeave(p);
+  return SQLITE_OK;
+}
+
+/*
+** Change the way data is synced to disk in order to increase or decrease
+** how well the database resists damage due to OS crashes and power
+** failures.  Level 1 is the same as asynchronous (no syncs() occur and
+** there is a high probability of damage)  Level 2 is the default.  There
+** is a very low but non-zero probability of damage.  Level 3 reduces the
+** probability of damage to near zero but with a write performance reduction.
+*/
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+int sqlite3BtreeSetSafetyLevel(Btree *p, int level, int fullSync){
+  BtShared *pBt = p->pBt;
+  assert( sqlite3_mutex_held(p->db->mutex) );
+  sqlite3BtreeEnter(p);
+  sqlite3PagerSetSafetyLevel(pBt->pPager, level, fullSync);
+  sqlite3BtreeLeave(p);
+  return SQLITE_OK;
+}
+#endif
+
+/*
+** Return TRUE if the given btree is set to safety level 1.  In other
+** words, return TRUE if no sync() occurs on the disk files.
+*/
+int sqlite3BtreeSyncDisabled(Btree *p){
+  BtShared *pBt = p->pBt;
+  int rc;
+  assert( sqlite3_mutex_held(p->db->mutex) );  
+  sqlite3BtreeEnter(p);
+  assert( pBt && pBt->pPager );
+  rc = sqlite3PagerNosync(pBt->pPager);
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM)
+/*
+** Change the default pages size and the number of reserved bytes per page.
+**
+** The page size must be a power of 2 between 512 and 65536.  If the page
+** size supplied does not meet this constraint then the page size is not
+** changed.
+**
+** Page sizes are constrained to be a power of two so that the region
+** of the database file used for locking (beginning at PENDING_BYTE,
+** the first byte past the 1GB boundary, 0x40000000) needs to occur
+** at the beginning of a page.
+**
+** If parameter nReserve is less than zero, then the number of reserved
+** bytes per page is left unchanged.
+*/
+int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve){
+  int rc = SQLITE_OK;
+  BtShared *pBt = p->pBt;
+  sqlite3BtreeEnter(p);
+  if( pBt->pageSizeFixed ){
+    sqlite3BtreeLeave(p);
+    return SQLITE_READONLY;
+  }
+  if( nReserve<0 ){
+    nReserve = pBt->pageSize - pBt->usableSize;
+  }
+  if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE &&
+        ((pageSize-1)&pageSize)==0 ){
+    assert( (pageSize & 7)==0 );
+    assert( !pBt->pPage1 && !pBt->pCursor );
+    pBt->pageSize = pageSize;
+    freeTempSpace(pBt);
+    rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize);
+  }
+  pBt->usableSize = pBt->pageSize - nReserve;
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+/*
+** Return the currently defined page size
+*/
+int sqlite3BtreeGetPageSize(Btree *p){
+  return p->pBt->pageSize;
+}
+int sqlite3BtreeGetReserve(Btree *p){
+  int n;
+  sqlite3BtreeEnter(p);
+  n = p->pBt->pageSize - p->pBt->usableSize;
+  sqlite3BtreeLeave(p);
+  return n;
+}
+
+/*
+** Set the maximum page count for a database if mxPage is positive.
+** No changes are made if mxPage is 0 or negative.
+** Regardless of the value of mxPage, return the maximum page count.
+*/
+int sqlite3BtreeMaxPageCount(Btree *p, int mxPage){
+  int n;
+  sqlite3BtreeEnter(p);
+  n = sqlite3PagerMaxPageCount(p->pBt->pPager, mxPage);
+  sqlite3BtreeLeave(p);
+  return n;
+}
+#endif /* !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM) */
+
+/*
+** Change the 'auto-vacuum' property of the database. If the 'autoVacuum'
+** parameter is non-zero, then auto-vacuum mode is enabled. If zero, it
+** is disabled. The default value for the auto-vacuum property is 
+** determined by the SQLITE_DEFAULT_AUTOVACUUM macro.
+*/
+int sqlite3BtreeSetAutoVacuum(Btree *p, int autoVacuum){
+#ifdef SQLITE_OMIT_AUTOVACUUM
+  return SQLITE_READONLY;
+#else
+  BtShared *pBt = p->pBt;
+  int rc = SQLITE_OK;
+  int av = (autoVacuum?1:0);
+
+  sqlite3BtreeEnter(p);
+  if( pBt->pageSizeFixed && av!=pBt->autoVacuum ){
+    rc = SQLITE_READONLY;
+  }else{
+    pBt->autoVacuum = av;
+  }
+  sqlite3BtreeLeave(p);
+  return rc;
+#endif
+}
+
+/*
+** Return the value of the 'auto-vacuum' property. If auto-vacuum is 
+** enabled 1 is returned. Otherwise 0.
+*/
+int sqlite3BtreeGetAutoVacuum(Btree *p){
+#ifdef SQLITE_OMIT_AUTOVACUUM
+  return BTREE_AUTOVACUUM_NONE;
+#else
+  int rc;
+  sqlite3BtreeEnter(p);
+  rc = (
+    (!p->pBt->autoVacuum)?BTREE_AUTOVACUUM_NONE:
+    (!p->pBt->incrVacuum)?BTREE_AUTOVACUUM_FULL:
+    BTREE_AUTOVACUUM_INCR
+  );
+  sqlite3BtreeLeave(p);
+  return rc;
+#endif
+}
+
+
+/*
+** Get a reference to pPage1 of the database file.  This will
+** also acquire a readlock on that file.
+**
+** SQLITE_OK is returned on success.  If the file is not a
+** well-formed database file, then SQLITE_CORRUPT is returned.
+** SQLITE_BUSY is returned if the database is locked.  SQLITE_NOMEM
+** is returned if we run out of memory. 
+*/
+static int lockBtree(BtShared *pBt){
+  int rc;
+  MemPage *pPage1;
+  int nPage;
+
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  if( pBt->pPage1 ) return SQLITE_OK;
+  rc = sqlite3BtreeGetPage(pBt, 1, &pPage1, 0);
+  if( rc!=SQLITE_OK ) return rc;
+
+  /* Do some checking to help insure the file we opened really is
+  ** a valid database file. 
+  */
+  rc = sqlite3PagerPagecount(pBt->pPager, &nPage);
+  if( rc!=SQLITE_OK ){
+    goto page1_init_failed;
+  }else if( nPage>0 ){
+    int pageSize;
+    int usableSize;
+    u8 *page1 = pPage1->aData;
+    rc = SQLITE_NOTADB;
+    if( memcmp(page1, zMagicHeader, 16)!=0 ){
+      goto page1_init_failed;
+    }
+    if( page1[18]>1 ){
+      pBt->readOnly = 1;
+    }
+    if( page1[19]>1 ){
+      goto page1_init_failed;
+    }
+
+    /* The maximum embedded fraction must be exactly 25%.  And the minimum
+    ** embedded fraction must be 12.5% for both leaf-data and non-leaf-data.
+    ** The original design allowed these amounts to vary, but as of
+    ** version 3.6.0, we require them to be fixed.
+    */
+    if( memcmp(&page1[21], "\100\040\040",3)!=0 ){
+      goto page1_init_failed;
+    }
+    pageSize = get2byte(&page1[16]);
+    if( ((pageSize-1)&pageSize)!=0 || pageSize<512 ||
+        (SQLITE_MAX_PAGE_SIZE<32768 && pageSize>SQLITE_MAX_PAGE_SIZE)
+    ){
+      goto page1_init_failed;
+    }
+    assert( (pageSize & 7)==0 );
+    usableSize = pageSize - page1[20];
+    if( pageSize!=pBt->pageSize ){
+      /* After reading the first page of the database assuming a page size
+      ** of BtShared.pageSize, we have discovered that the page-size is
+      ** actually pageSize. Unlock the database, leave pBt->pPage1 at
+      ** zero and return SQLITE_OK. The caller will call this function
+      ** again with the correct page-size.
+      */
+      releasePage(pPage1);
+      pBt->usableSize = usableSize;
+      pBt->pageSize = pageSize;
+      freeTempSpace(pBt);
+      sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize);
+      return SQLITE_OK;
+    }
+    if( usableSize<500 ){
+      goto page1_init_failed;
+    }
+    pBt->pageSize = pageSize;
+    pBt->usableSize = usableSize;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    pBt->autoVacuum = (get4byte(&page1[36 + 4*4])?1:0);
+    pBt->incrVacuum = (get4byte(&page1[36 + 7*4])?1:0);
+#endif
+  }
+
+  /* maxLocal is the maximum amount of payload to store locally for
+  ** a cell.  Make sure it is small enough so that at least minFanout
+  ** cells can will fit on one page.  We assume a 10-byte page header.
+  ** Besides the payload, the cell must store:
+  **     2-byte pointer to the cell
+  **     4-byte child pointer
+  **     9-byte nKey value
+  **     4-byte nData value
+  **     4-byte overflow page pointer
+  ** So a cell consists of a 2-byte poiner, a header which is as much as
+  ** 17 bytes long, 0 to N bytes of payload, and an optional 4 byte overflow
+  ** page pointer.
+  */
+  pBt->maxLocal = (pBt->usableSize-12)*64/255 - 23;
+  pBt->minLocal = (pBt->usableSize-12)*32/255 - 23;
+  pBt->maxLeaf = pBt->usableSize - 35;
+  pBt->minLeaf = (pBt->usableSize-12)*32/255 - 23;
+  assert( pBt->maxLeaf + 23 <= MX_CELL_SIZE(pBt) );
+  pBt->pPage1 = pPage1;
+  return SQLITE_OK;
+
+page1_init_failed:
+  releasePage(pPage1);
+  pBt->pPage1 = 0;
+  return rc;
+}
+
+/*
+** This routine works like lockBtree() except that it also invokes the
+** busy callback if there is lock contention.
+*/
+static int lockBtreeWithRetry(Btree *pRef){
+  int rc = SQLITE_OK;
+
+  assert( sqlite3BtreeHoldsMutex(pRef) );
+  if( pRef->inTrans==TRANS_NONE ){
+    u8 inTransaction = pRef->pBt->inTransaction;
+    btreeIntegrity(pRef);
+    rc = sqlite3BtreeBeginTrans(pRef, 0);
+    pRef->pBt->inTransaction = inTransaction;
+    pRef->inTrans = TRANS_NONE;
+    if( rc==SQLITE_OK ){
+      pRef->pBt->nTransaction--;
+    }
+    btreeIntegrity(pRef);
+  }
+  return rc;
+}
+       
+
+/*
+** If there are no outstanding cursors and we are not in the middle
+** of a transaction but there is a read lock on the database, then
+** this routine unrefs the first page of the database file which 
+** has the effect of releasing the read lock.
+**
+** If there are any outstanding cursors, this routine is a no-op.
+**
+** If there is a transaction in progress, this routine is a no-op.
+*/
+static void unlockBtreeIfUnused(BtShared *pBt){
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  if( pBt->inTransaction==TRANS_NONE && pBt->pCursor==0 && pBt->pPage1!=0 ){
+    if( sqlite3PagerRefcount(pBt->pPager)>=1 ){
+      assert( pBt->pPage1->aData );
+#if 0
+      if( pBt->pPage1->aData==0 ){
+        MemPage *pPage = pBt->pPage1;
+        pPage->aData = sqlite3PagerGetData(pPage->pDbPage);
+        pPage->pBt = pBt;
+        pPage->pgno = 1;
+      }
+#endif
+      releasePage(pBt->pPage1);
+    }
+    pBt->pPage1 = 0;
+    pBt->inStmt = 0;
+  }
+}
+
+/*
+** Create a new database by initializing the first page of the
+** file.
+*/
+static int newDatabase(BtShared *pBt){
+  MemPage *pP1;
+  unsigned char *data;
+  int rc;
+  int nPage;
+
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  rc = sqlite3PagerPagecount(pBt->pPager, &nPage);
+  if( rc!=SQLITE_OK || nPage>0 ){
+    return rc;
+  }
+  pP1 = pBt->pPage1;
+  assert( pP1!=0 );
+  data = pP1->aData;
+  rc = sqlite3PagerWrite(pP1->pDbPage);
+  if( rc ) return rc;
+  memcpy(data, zMagicHeader, sizeof(zMagicHeader));
+  assert( sizeof(zMagicHeader)==16 );
+  assert( sizeof(zMagicHeader)==sizeof(zPoisonHeader) );
+  put2byte(&data[16], pBt->pageSize);
+  data[18] = 1;
+  data[19] = 1;
+  data[20] = pBt->pageSize - pBt->usableSize;
+  data[21] = 64;
+  data[22] = 32;
+  data[23] = 32;
+  memset(&data[24], 0, 100-24);
+  zeroPage(pP1, PTF_INTKEY|PTF_LEAF|PTF_LEAFDATA );
+  pBt->pageSizeFixed = 1;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+  assert( pBt->autoVacuum==1 || pBt->autoVacuum==0 );
+  assert( pBt->incrVacuum==1 || pBt->incrVacuum==0 );
+  put4byte(&data[36 + 4*4], pBt->autoVacuum);
+  put4byte(&data[36 + 7*4], pBt->incrVacuum);
+#endif
+  return SQLITE_OK;
+}
+
+/*
+** Attempt to start a new transaction. A write-transaction
+** is started if the second argument is nonzero, otherwise a read-
+** transaction.  If the second argument is 2 or more and exclusive
+** transaction is started, meaning that no other process is allowed
+** to access the database.  A preexisting transaction may not be
+** upgraded to exclusive by calling this routine a second time - the
+** exclusivity flag only works for a new transaction.
+**
+** A write-transaction must be started before attempting any 
+** changes to the database.  None of the following routines 
+** will work unless a transaction is started first:
+**
+**      sqlite3BtreeCreateTable()
+**      sqlite3BtreeCreateIndex()
+**      sqlite3BtreeClearTable()
+**      sqlite3BtreeDropTable()
+**      sqlite3BtreeInsert()
+**      sqlite3BtreeDelete()
+**      sqlite3BtreeUpdateMeta()
+**
+** If an initial attempt to acquire the lock fails because of lock contention
+** and the database was previously unlocked, then invoke the busy handler
+** if there is one.  But if there was previously a read-lock, do not
+** invoke the busy handler - just return SQLITE_BUSY.  SQLITE_BUSY is 
+** returned when there is already a read-lock in order to avoid a deadlock.
+**
+** Suppose there are two processes A and B.  A has a read lock and B has
+** a reserved lock.  B tries to promote to exclusive but is blocked because
+** of A's read lock.  A tries to promote to reserved but is blocked by B.
+** One or the other of the two processes must give way or there can be
+** no progress.  By returning SQLITE_BUSY and not invoking the busy callback
+** when A already has a read lock, we encourage A to give up and let B
+** proceed.
+*/
+int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
+  BtShared *pBt = p->pBt;
+  int rc = SQLITE_OK;
+
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+  btreeIntegrity(p);
+
+  /* If the btree is already in a write-transaction, or it
+  ** is already in a read-transaction and a read-transaction
+  ** is requested, this is a no-op.
+  */
+  if( p->inTrans==TRANS_WRITE || (p->inTrans==TRANS_READ && !wrflag) ){
+    goto trans_begun;
+  }
+
+  /* Write transactions are not possible on a read-only database */
+  if( pBt->readOnly && wrflag ){
+    rc = SQLITE_READONLY;
+    goto trans_begun;
+  }
+
+  /* If another database handle has already opened a write transaction 
+  ** on this shared-btree structure and a second write transaction is
+  ** requested, return SQLITE_BUSY.
+  */
+  if( pBt->inTransaction==TRANS_WRITE && wrflag ){
+    rc = SQLITE_BUSY;
+    goto trans_begun;
+  }
+
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  if( wrflag>1 ){
+    BtLock *pIter;
+    for(pIter=pBt->pLock; pIter; pIter=pIter->pNext){
+      if( pIter->pBtree!=p ){
+        rc = SQLITE_BUSY;
+        goto trans_begun;
+      }
+    }
+  }
+#endif
+
+  do {
+    if( pBt->pPage1==0 ){
+      do{
+        rc = lockBtree(pBt);
+      }while( pBt->pPage1==0 && rc==SQLITE_OK );
+    }
+
+    if( rc==SQLITE_OK && wrflag ){
+      if( pBt->readOnly ){
+        rc = SQLITE_READONLY;
+      }else{
+        rc = sqlite3PagerBegin(pBt->pPage1->pDbPage, wrflag>1);
+        if( rc==SQLITE_OK ){
+          rc = newDatabase(pBt);
+        }
+      }
+    }
+  
+    if( rc==SQLITE_OK ){
+      if( wrflag ) pBt->inStmt = 0;
+    }else{
+      unlockBtreeIfUnused(pBt);
+    }
+  }while( rc==SQLITE_BUSY && pBt->inTransaction==TRANS_NONE &&
+          sqlite3BtreeInvokeBusyHandler(pBt, 0) );
+
+  if( rc==SQLITE_OK ){
+    if( p->inTrans==TRANS_NONE ){
+      pBt->nTransaction++;
+    }
+    p->inTrans = (wrflag?TRANS_WRITE:TRANS_READ);
+    if( p->inTrans>pBt->inTransaction ){
+      pBt->inTransaction = p->inTrans;
+    }
+#ifndef SQLITE_OMIT_SHARED_CACHE
+    if( wrflag>1 ){
+      assert( !pBt->pExclusive );
+      pBt->pExclusive = p;
+    }
+#endif
+  }
+
+
+trans_begun:
+  btreeIntegrity(p);
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+/*
+** Return the size of the database file in pages.  Or return -1 if
+** there is any kind of error.
+*/
+static int pagerPagecount(Pager *pPager){
+  int rc;
+  int nPage;
+  rc = sqlite3PagerPagecount(pPager, &nPage);
+  return (rc==SQLITE_OK?nPage:-1);
+}
+
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+
+/*
+** Set the pointer-map entries for all children of page pPage. Also, if
+** pPage contains cells that point to overflow pages, set the pointer
+** map entries for the overflow pages as well.
+*/
+static int setChildPtrmaps(MemPage *pPage){
+  int i;                             /* Counter variable */
+  int nCell;                         /* Number of cells in page pPage */
+  int rc;                            /* Return code */
+  BtShared *pBt = pPage->pBt;
+  int isInitOrig = pPage->isInit;
+  Pgno pgno = pPage->pgno;
+
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  rc = sqlite3BtreeInitPage(pPage, pPage->pParent);
+  if( rc!=SQLITE_OK ){
+    goto set_child_ptrmaps_out;
+  }
+  nCell = pPage->nCell;
+
+  for(i=0; i<nCell; i++){
+    u8 *pCell = findCell(pPage, i);
+
+    rc = ptrmapPutOvflPtr(pPage, pCell);
+    if( rc!=SQLITE_OK ){
+      goto set_child_ptrmaps_out;
+    }
+
+    if( !pPage->leaf ){
+      Pgno childPgno = get4byte(pCell);
+      rc = ptrmapPut(pBt, childPgno, PTRMAP_BTREE, pgno);
+       if( rc!=SQLITE_OK ) goto set_child_ptrmaps_out;
+    }
+  }
+
+  if( !pPage->leaf ){
+    Pgno childPgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
+    rc = ptrmapPut(pBt, childPgno, PTRMAP_BTREE, pgno);
+  }
+
+set_child_ptrmaps_out:
+  pPage->isInit = isInitOrig;
+  return rc;
+}
+
+/*
+** Somewhere on pPage, which is guarenteed to be a btree page, not an overflow
+** page, is a pointer to page iFrom. Modify this pointer so that it points to
+** iTo. Parameter eType describes the type of pointer to be modified, as 
+** follows:
+**
+** PTRMAP_BTREE:     pPage is a btree-page. The pointer points at a child 
+**                   page of pPage.
+**
+** PTRMAP_OVERFLOW1: pPage is a btree-page. The pointer points at an overflow
+**                   page pointed to by one of the cells on pPage.
+**
+** PTRMAP_OVERFLOW2: pPage is an overflow-page. The pointer points at the next
+**                   overflow page in the list.
+*/
+static int modifyPagePointer(MemPage *pPage, Pgno iFrom, Pgno iTo, u8 eType){
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  if( eType==PTRMAP_OVERFLOW2 ){
+    /* The pointer is always the first 4 bytes of the page in this case.  */
+    if( get4byte(pPage->aData)!=iFrom ){
+      return SQLITE_CORRUPT_BKPT;
+    }
+    put4byte(pPage->aData, iTo);
+  }else{
+    int isInitOrig = pPage->isInit;
+    int i;
+    int nCell;
+
+    sqlite3BtreeInitPage(pPage, 0);
+    nCell = pPage->nCell;
+
+    for(i=0; i<nCell; i++){
+      u8 *pCell = findCell(pPage, i);
+      if( eType==PTRMAP_OVERFLOW1 ){
+        CellInfo info;
+        sqlite3BtreeParseCellPtr(pPage, pCell, &info);
+        if( info.iOverflow ){
+          if( iFrom==get4byte(&pCell[info.iOverflow]) ){
+            put4byte(&pCell[info.iOverflow], iTo);
+            break;
+          }
+        }
+      }else{
+        if( get4byte(pCell)==iFrom ){
+          put4byte(pCell, iTo);
+          break;
+        }
+      }
+    }
+  
+    if( i==nCell ){
+      if( eType!=PTRMAP_BTREE || 
+          get4byte(&pPage->aData[pPage->hdrOffset+8])!=iFrom ){
+        return SQLITE_CORRUPT_BKPT;
+      }
+      put4byte(&pPage->aData[pPage->hdrOffset+8], iTo);
+    }
+
+    pPage->isInit = isInitOrig;
+  }
+  return SQLITE_OK;
+}
+
+
+/*
+** Move the open database page pDbPage to location iFreePage in the 
+** database. The pDbPage reference remains valid.
+*/
+static int relocatePage(
+  BtShared *pBt,           /* Btree */
+  MemPage *pDbPage,        /* Open page to move */
+  u8 eType,                /* Pointer map 'type' entry for pDbPage */
+  Pgno iPtrPage,           /* Pointer map 'page-no' entry for pDbPage */
+  Pgno iFreePage,          /* The location to move pDbPage to */
+  int isCommit
+){
+  MemPage *pPtrPage;   /* The page that contains a pointer to pDbPage */
+  Pgno iDbPage = pDbPage->pgno;
+  Pager *pPager = pBt->pPager;
+  int rc;
+
+  assert( eType==PTRMAP_OVERFLOW2 || eType==PTRMAP_OVERFLOW1 || 
+      eType==PTRMAP_BTREE || eType==PTRMAP_ROOTPAGE );
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  assert( pDbPage->pBt==pBt );
+
+  /* Move page iDbPage from its current location to page number iFreePage */
+  TRACE(("AUTOVACUUM: Moving %d to free page %d (ptr page %d type %d)\n", 
+      iDbPage, iFreePage, iPtrPage, eType));
+  rc = sqlite3PagerMovepage(pPager, pDbPage->pDbPage, iFreePage, isCommit);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+  pDbPage->pgno = iFreePage;
+
+  /* If pDbPage was a btree-page, then it may have child pages and/or cells
+  ** that point to overflow pages. The pointer map entries for all these
+  ** pages need to be changed.
+  **
+  ** If pDbPage is an overflow page, then the first 4 bytes may store a
+  ** pointer to a subsequent overflow page. If this is the case, then
+  ** the pointer map needs to be updated for the subsequent overflow page.
+  */
+  if( eType==PTRMAP_BTREE || eType==PTRMAP_ROOTPAGE ){
+    rc = setChildPtrmaps(pDbPage);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+  }else{
+    Pgno nextOvfl = get4byte(pDbPage->aData);
+    if( nextOvfl!=0 ){
+      rc = ptrmapPut(pBt, nextOvfl, PTRMAP_OVERFLOW2, iFreePage);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+    }
+  }
+
+  /* Fix the database pointer on page iPtrPage that pointed at iDbPage so
+  ** that it points at iFreePage. Also fix the pointer map entry for
+  ** iPtrPage.
+  */
+  if( eType!=PTRMAP_ROOTPAGE ){
+    rc = sqlite3BtreeGetPage(pBt, iPtrPage, &pPtrPage, 0);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    rc = sqlite3PagerWrite(pPtrPage->pDbPage);
+    if( rc!=SQLITE_OK ){
+      releasePage(pPtrPage);
+      return rc;
+    }
+    rc = modifyPagePointer(pPtrPage, iDbPage, iFreePage, eType);
+    releasePage(pPtrPage);
+    if( rc==SQLITE_OK ){
+      rc = ptrmapPut(pBt, iFreePage, eType, iPtrPage);
+    }
+  }
+  return rc;
+}
+
+/* Forward declaration required by incrVacuumStep(). */
+static int allocateBtreePage(BtShared *, MemPage **, Pgno *, Pgno, u8);
+
+/*
+** Perform a single step of an incremental-vacuum. If successful,
+** return SQLITE_OK. If there is no work to do (and therefore no
+** point in calling this function again), return SQLITE_DONE.
+**
+** More specificly, this function attempts to re-organize the 
+** database so that the last page of the file currently in use
+** is no longer in use.
+**
+** If the nFin parameter is non-zero, the implementation assumes
+** that the caller will keep calling incrVacuumStep() until
+** it returns SQLITE_DONE or an error, and that nFin is the
+** number of pages the database file will contain after this 
+** process is complete.
+*/
+static int incrVacuumStep(BtShared *pBt, Pgno nFin){
+  Pgno iLastPg;             /* Last page in the database */
+  Pgno nFreeList;           /* Number of pages still on the free-list */
+
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  iLastPg = pBt->nTrunc;
+  if( iLastPg==0 ){
+    iLastPg = pagerPagecount(pBt->pPager);
+  }
+
+  if( !PTRMAP_ISPAGE(pBt, iLastPg) && iLastPg!=PENDING_BYTE_PAGE(pBt) ){
+    int rc;
+    u8 eType;
+    Pgno iPtrPage;
+
+    nFreeList = get4byte(&pBt->pPage1->aData[36]);
+    if( nFreeList==0 || nFin==iLastPg ){
+      return SQLITE_DONE;
+    }
+
+    rc = ptrmapGet(pBt, iLastPg, &eType, &iPtrPage);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    if( eType==PTRMAP_ROOTPAGE ){
+      return SQLITE_CORRUPT_BKPT;
+    }
+
+    if( eType==PTRMAP_FREEPAGE ){
+      if( nFin==0 ){
+        /* Remove the page from the files free-list. This is not required
+        ** if nFin is non-zero. In that case, the free-list will be
+        ** truncated to zero after this function returns, so it doesn't 
+        ** matter if it still contains some garbage entries.
+        */
+        Pgno iFreePg;
+        MemPage *pFreePg;
+        rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, iLastPg, 1);
+        if( rc!=SQLITE_OK ){
+          return rc;
+        }
+        assert( iFreePg==iLastPg );
+        releasePage(pFreePg);
+      }
+    } else {
+      Pgno iFreePg;             /* Index of free page to move pLastPg to */
+      MemPage *pLastPg;
+
+      rc = sqlite3BtreeGetPage(pBt, iLastPg, &pLastPg, 0);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+
+      /* If nFin is zero, this loop runs exactly once and page pLastPg
+      ** is swapped with the first free page pulled off the free list.
+      **
+      ** On the other hand, if nFin is greater than zero, then keep
+      ** looping until a free-page located within the first nFin pages
+      ** of the file is found.
+      */
+      do {
+        MemPage *pFreePg;
+        rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, 0, 0);
+        if( rc!=SQLITE_OK ){
+          releasePage(pLastPg);
+          return rc;
+        }
+        releasePage(pFreePg);
+      }while( nFin!=0 && iFreePg>nFin );
+      assert( iFreePg<iLastPg );
+      
+      rc = sqlite3PagerWrite(pLastPg->pDbPage);
+      if( rc==SQLITE_OK ){
+        rc = relocatePage(pBt, pLastPg, eType, iPtrPage, iFreePg, nFin!=0);
+      }
+      releasePage(pLastPg);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+    }
+  }
+
+  pBt->nTrunc = iLastPg - 1;
+  while( pBt->nTrunc==PENDING_BYTE_PAGE(pBt)||PTRMAP_ISPAGE(pBt, pBt->nTrunc) ){
+    pBt->nTrunc--;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** A write-transaction must be opened before calling this function.
+** It performs a single unit of work towards an incremental vacuum.
+**
+** If the incremental vacuum is finished after this function has run,
+** SQLITE_DONE is returned. If it is not finished, but no error occured,
+** SQLITE_OK is returned. Otherwise an SQLite error code. 
+*/
+int sqlite3BtreeIncrVacuum(Btree *p){
+  int rc;
+  BtShared *pBt = p->pBt;
+
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+  assert( pBt->inTransaction==TRANS_WRITE && p->inTrans==TRANS_WRITE );
+  if( !pBt->autoVacuum ){
+    rc = SQLITE_DONE;
+  }else{
+    invalidateAllOverflowCache(pBt);
+    rc = incrVacuumStep(pBt, 0);
+  }
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+/*
+** This routine is called prior to sqlite3PagerCommit when a transaction
+** is commited for an auto-vacuum database.
+**
+** If SQLITE_OK is returned, then *pnTrunc is set to the number of pages
+** the database file should be truncated to during the commit process. 
+** i.e. the database has been reorganized so that only the first *pnTrunc
+** pages are in use.
+*/
+static int autoVacuumCommit(BtShared *pBt, Pgno *pnTrunc){
+  int rc = SQLITE_OK;
+  Pager *pPager = pBt->pPager;
+#ifndef NDEBUG
+  int nRef = sqlite3PagerRefcount(pPager);
+#endif
+
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  invalidateAllOverflowCache(pBt);
+  assert(pBt->autoVacuum);
+  if( !pBt->incrVacuum ){
+    Pgno nFin = 0;
+
+    if( pBt->nTrunc==0 ){
+      Pgno nFree;
+      Pgno nPtrmap;
+      const int pgsz = pBt->pageSize;
+      int nOrig = pagerPagecount(pBt->pPager);
+
+      if( PTRMAP_ISPAGE(pBt, nOrig) ){
+        return SQLITE_CORRUPT_BKPT;
+      }
+      if( nOrig==PENDING_BYTE_PAGE(pBt) ){
+        nOrig--;
+      }
+      nFree = get4byte(&pBt->pPage1->aData[36]);
+      nPtrmap = (nFree-nOrig+PTRMAP_PAGENO(pBt, nOrig)+pgsz/5)/(pgsz/5);
+      nFin = nOrig - nFree - nPtrmap;
+      if( nOrig>PENDING_BYTE_PAGE(pBt) && nFin<=PENDING_BYTE_PAGE(pBt) ){
+        nFin--;
+      }
+      while( PTRMAP_ISPAGE(pBt, nFin) || nFin==PENDING_BYTE_PAGE(pBt) ){
+        nFin--;
+      }
+    }
+
+    while( rc==SQLITE_OK ){
+      rc = incrVacuumStep(pBt, nFin);
+    }
+    if( rc==SQLITE_DONE ){
+      assert(nFin==0 || pBt->nTrunc==0 || nFin<=pBt->nTrunc);
+      rc = SQLITE_OK;
+      if( pBt->nTrunc && nFin ){
+        rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
+        put4byte(&pBt->pPage1->aData[32], 0);
+        put4byte(&pBt->pPage1->aData[36], 0);
+        pBt->nTrunc = nFin;
+      }
+    }
+    if( rc!=SQLITE_OK ){
+      sqlite3PagerRollback(pPager);
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    *pnTrunc = pBt->nTrunc;
+    pBt->nTrunc = 0;
+  }
+  assert( nRef==sqlite3PagerRefcount(pPager) );
+  return rc;
+}
+
+#endif
+
+/*
+** This routine does the first phase of a two-phase commit.  This routine
+** causes a rollback journal to be created (if it does not already exist)
+** and populated with enough information so that if a power loss occurs
+** the database can be restored to its original state by playing back
+** the journal.  Then the contents of the journal are flushed out to
+** the disk.  After the journal is safely on oxide, the changes to the
+** database are written into the database file and flushed to oxide.
+** At the end of this call, the rollback journal still exists on the
+** disk and we are still holding all locks, so the transaction has not
+** committed.  See sqlite3BtreeCommit() for the second phase of the
+** commit process.
+**
+** This call is a no-op if no write-transaction is currently active on pBt.
+**
+** Otherwise, sync the database file for the btree pBt. zMaster points to
+** the name of a master journal file that should be written into the
+** individual journal file, or is NULL, indicating no master journal file 
+** (single database transaction).
+**
+** When this is called, the master journal should already have been
+** created, populated with this journal pointer and synced to disk.
+**
+** Once this is routine has returned, the only thing required to commit
+** the write-transaction for this database file is to delete the journal.
+*/
+int sqlite3BtreeCommitPhaseOne(Btree *p, const char *zMaster){
+  int rc = SQLITE_OK;
+  if( p->inTrans==TRANS_WRITE ){
+    BtShared *pBt = p->pBt;
+    Pgno nTrunc = 0;
+    sqlite3BtreeEnter(p);
+    pBt->db = p->db;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    if( pBt->autoVacuum ){
+      rc = autoVacuumCommit(pBt, &nTrunc); 
+      if( rc!=SQLITE_OK ){
+        sqlite3BtreeLeave(p);
+        return rc;
+      }
+    }
+#endif
+    rc = sqlite3PagerCommitPhaseOne(pBt->pPager, zMaster, nTrunc, 0);
+    sqlite3BtreeLeave(p);
+  }
+  return rc;
+}
+
+/*
+** Commit the transaction currently in progress.
+**
+** This routine implements the second phase of a 2-phase commit.  The
+** sqlite3BtreeSync() routine does the first phase and should be invoked
+** prior to calling this routine.  The sqlite3BtreeSync() routine did
+** all the work of writing information out to disk and flushing the
+** contents so that they are written onto the disk platter.  All this
+** routine has to do is delete or truncate the rollback journal
+** (which causes the transaction to commit) and drop locks.
+**
+** This will release the write lock on the database file.  If there
+** are no active cursors, it also releases the read lock.
+*/
+int sqlite3BtreeCommitPhaseTwo(Btree *p){
+  BtShared *pBt = p->pBt;
+
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+  btreeIntegrity(p);
+
+  /* If the handle has a write-transaction open, commit the shared-btrees 
+  ** transaction and set the shared state to TRANS_READ.
+  */
+  if( p->inTrans==TRANS_WRITE ){
+    int rc;
+    assert( pBt->inTransaction==TRANS_WRITE );
+    assert( pBt->nTransaction>0 );
+    rc = sqlite3PagerCommitPhaseTwo(pBt->pPager);
+    if( rc!=SQLITE_OK ){
+      sqlite3BtreeLeave(p);
+      return rc;
+    }
+    pBt->inTransaction = TRANS_READ;
+    pBt->inStmt = 0;
+  }
+  unlockAllTables(p);
+
+  /* If the handle has any kind of transaction open, decrement the transaction
+  ** count of the shared btree. If the transaction count reaches 0, set
+  ** the shared state to TRANS_NONE. The unlockBtreeIfUnused() call below
+  ** will unlock the pager.
+  */
+  if( p->inTrans!=TRANS_NONE ){
+    pBt->nTransaction--;
+    if( 0==pBt->nTransaction ){
+      pBt->inTransaction = TRANS_NONE;
+    }
+  }
+
+  /* Set the handles current transaction state to TRANS_NONE and unlock
+  ** the pager if this call closed the only read or write transaction.
+  */
+  p->inTrans = TRANS_NONE;
+  unlockBtreeIfUnused(pBt);
+
+  btreeIntegrity(p);
+  sqlite3BtreeLeave(p);
+  return SQLITE_OK;
+}
+
+/*
+** Do both phases of a commit.
+*/
+int sqlite3BtreeCommit(Btree *p){
+  int rc;
+  sqlite3BtreeEnter(p);
+  rc = sqlite3BtreeCommitPhaseOne(p, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3BtreeCommitPhaseTwo(p);
+  }
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+#ifndef NDEBUG
+/*
+** Return the number of write-cursors open on this handle. This is for use
+** in assert() expressions, so it is only compiled if NDEBUG is not
+** defined.
+**
+** For the purposes of this routine, a write-cursor is any cursor that
+** is capable of writing to the databse.  That means the cursor was
+** originally opened for writing and the cursor has not be disabled
+** by having its state changed to CURSOR_FAULT.
+*/
+static int countWriteCursors(BtShared *pBt){
+  BtCursor *pCur;
+  int r = 0;
+  for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
+    if( pCur->wrFlag && pCur->eState!=CURSOR_FAULT ) r++; 
+  }
+  return r;
+}
+#endif
+
+/*
+** This routine sets the state to CURSOR_FAULT and the error
+** code to errCode for every cursor on BtShared that pBtree
+** references.
+**
+** Every cursor is tripped, including cursors that belong
+** to other database connections that happen to be sharing
+** the cache with pBtree.
+**
+** This routine gets called when a rollback occurs.
+** All cursors using the same cache must be tripped
+** to prevent them from trying to use the btree after
+** the rollback.  The rollback may have deleted tables
+** or moved root pages, so it is not sufficient to
+** save the state of the cursor.  The cursor must be
+** invalidated.
+*/
+void sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode){
+  BtCursor *p;
+  sqlite3BtreeEnter(pBtree);
+  for(p=pBtree->pBt->pCursor; p; p=p->pNext){
+    clearCursorPosition(p);
+    p->eState = CURSOR_FAULT;
+    p->skip = errCode;
+  }
+  sqlite3BtreeLeave(pBtree);
+}
+
+/*
+** Rollback the transaction in progress.  All cursors will be
+** invalided by this operation.  Any attempt to use a cursor
+** that was open at the beginning of this operation will result
+** in an error.
+**
+** This will release the write lock on the database file.  If there
+** are no active cursors, it also releases the read lock.
+*/
+int sqlite3BtreeRollback(Btree *p){
+  int rc;
+  BtShared *pBt = p->pBt;
+  MemPage *pPage1;
+
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+  rc = saveAllCursors(pBt, 0, 0);
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  if( rc!=SQLITE_OK ){
+    /* This is a horrible situation. An IO or malloc() error occured whilst
+    ** trying to save cursor positions. If this is an automatic rollback (as
+    ** the result of a constraint, malloc() failure or IO error) then 
+    ** the cache may be internally inconsistent (not contain valid trees) so
+    ** we cannot simply return the error to the caller. Instead, abort 
+    ** all queries that may be using any of the cursors that failed to save.
+    */
+    sqlite3BtreeTripAllCursors(p, rc);
+  }
+#endif
+  btreeIntegrity(p);
+  unlockAllTables(p);
+
+  if( p->inTrans==TRANS_WRITE ){
+    int rc2;
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    pBt->nTrunc = 0;
+#endif
+
+    assert( TRANS_WRITE==pBt->inTransaction );
+    rc2 = sqlite3PagerRollback(pBt->pPager);
+    if( rc2!=SQLITE_OK ){
+      rc = rc2;
+    }
+
+    /* The rollback may have destroyed the pPage1->aData value.  So
+    ** call sqlite3BtreeGetPage() on page 1 again to make
+    ** sure pPage1->aData is set correctly. */
+    if( sqlite3BtreeGetPage(pBt, 1, &pPage1, 0)==SQLITE_OK ){
+      releasePage(pPage1);
+    }
+    assert( countWriteCursors(pBt)==0 );
+    pBt->inTransaction = TRANS_READ;
+  }
+
+  if( p->inTrans!=TRANS_NONE ){
+    assert( pBt->nTransaction>0 );
+    pBt->nTransaction--;
+    if( 0==pBt->nTransaction ){
+      pBt->inTransaction = TRANS_NONE;
+    }
+  }
+
+  p->inTrans = TRANS_NONE;
+  pBt->inStmt = 0;
+  unlockBtreeIfUnused(pBt);
+
+  btreeIntegrity(p);
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+/*
+** Start a statement subtransaction.  The subtransaction can
+** can be rolled back independently of the main transaction.
+** You must start a transaction before starting a subtransaction.
+** The subtransaction is ended automatically if the main transaction
+** commits or rolls back.
+**
+** Only one subtransaction may be active at a time.  It is an error to try
+** to start a new subtransaction if another subtransaction is already active.
+**
+** Statement subtransactions are used around individual SQL statements
+** that are contained within a BEGIN...COMMIT block.  If a constraint
+** error occurs within the statement, the effect of that one statement
+** can be rolled back without having to rollback the entire transaction.
+*/
+int sqlite3BtreeBeginStmt(Btree *p){
+  int rc;
+  BtShared *pBt = p->pBt;
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+  if( (p->inTrans!=TRANS_WRITE) || pBt->inStmt ){
+    rc = pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
+  }else{
+    assert( pBt->inTransaction==TRANS_WRITE );
+    rc = pBt->readOnly ? SQLITE_OK : sqlite3PagerStmtBegin(pBt->pPager);
+    pBt->inStmt = 1;
+  }
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+
+/*
+** Commit the statment subtransaction currently in progress.  If no
+** subtransaction is active, this is a no-op.
+*/
+int sqlite3BtreeCommitStmt(Btree *p){
+  int rc;
+  BtShared *pBt = p->pBt;
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+  if( pBt->inStmt && !pBt->readOnly ){
+    rc = sqlite3PagerStmtCommit(pBt->pPager);
+  }else{
+    rc = SQLITE_OK;
+  }
+  pBt->inStmt = 0;
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+/*
+** Rollback the active statement subtransaction.  If no subtransaction
+** is active this routine is a no-op.
+**
+** All cursors will be invalidated by this operation.  Any attempt
+** to use a cursor that was open at the beginning of this operation
+** will result in an error.
+*/
+int sqlite3BtreeRollbackStmt(Btree *p){
+  int rc = SQLITE_OK;
+  BtShared *pBt = p->pBt;
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+  if( pBt->inStmt && !pBt->readOnly ){
+    rc = sqlite3PagerStmtRollback(pBt->pPager);
+    pBt->inStmt = 0;
+  }
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+/*
+** Create a new cursor for the BTree whose root is on the page
+** iTable.  The act of acquiring a cursor gets a read lock on 
+** the database file.
+**
+** If wrFlag==0, then the cursor can only be used for reading.
+** If wrFlag==1, then the cursor can be used for reading or for
+** writing if other conditions for writing are also met.  These
+** are the conditions that must be met in order for writing to
+** be allowed:
+**
+** 1:  The cursor must have been opened with wrFlag==1
+**
+** 2:  Other database connections that share the same pager cache
+**     but which are not in the READ_UNCOMMITTED state may not have
+**     cursors open with wrFlag==0 on the same table.  Otherwise
+**     the changes made by this write cursor would be visible to
+**     the read cursors in the other database connection.
+**
+** 3:  The database must be writable (not on read-only media)
+**
+** 4:  There must be an active transaction.
+**
+** No checking is done to make sure that page iTable really is the
+** root page of a b-tree.  If it is not, then the cursor acquired
+** will not work correctly.
+*/
+static int btreeCursor(
+  Btree *p,                              /* The btree */
+  int iTable,                            /* Root page of table to open */
+  int wrFlag,                            /* 1 to write. 0 read-only */
+  struct KeyInfo *pKeyInfo,              /* First arg to comparison function */
+  BtCursor *pCur                         /* Space for new cursor */
+){
+  int rc;
+  BtShared *pBt = p->pBt;
+
+  assert( sqlite3BtreeHoldsMutex(p) );
+  if( wrFlag ){
+    if( pBt->readOnly ){
+      return SQLITE_READONLY;
+    }
+    if( checkReadLocks(p, iTable, 0, 0) ){
+      return SQLITE_LOCKED;
+    }
+  }
+
+  if( pBt->pPage1==0 ){
+    rc = lockBtreeWithRetry(p);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    if( pBt->readOnly && wrFlag ){
+      return SQLITE_READONLY;
+    }
+  }
+  pCur->pgnoRoot = (Pgno)iTable;
+  if( iTable==1 && pagerPagecount(pBt->pPager)==0 ){
+    rc = SQLITE_EMPTY;
+    goto create_cursor_exception;
+  }
+  rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->pPage, 0);
+  if( rc!=SQLITE_OK ){
+    goto create_cursor_exception;
+  }
+
+  /* Now that no other errors can occur, finish filling in the BtCursor
+  ** variables, link the cursor into the BtShared list and set *ppCur (the
+  ** output argument to this function).
+  */
+  pCur->pKeyInfo = pKeyInfo;
+  pCur->pBtree = p;
+  pCur->pBt = pBt;
+  pCur->wrFlag = wrFlag;
+  pCur->pNext = pBt->pCursor;
+  if( pCur->pNext ){
+    pCur->pNext->pPrev = pCur;
+  }
+  pBt->pCursor = pCur;
+  pCur->eState = CURSOR_INVALID;
+
+  return SQLITE_OK;
+
+create_cursor_exception:
+  releasePage(pCur->pPage);
+  unlockBtreeIfUnused(pBt);
+  return rc;
+}
+int sqlite3BtreeCursor(
+  Btree *p,                                   /* The btree */
+  int iTable,                                 /* Root page of table to open */
+  int wrFlag,                                 /* 1 to write. 0 read-only */
+  struct KeyInfo *pKeyInfo,                   /* First arg to xCompare() */
+  BtCursor *pCur                              /* Write new cursor here */
+){
+  int rc;
+  sqlite3BtreeEnter(p);
+  p->pBt->db = p->db;
+  rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, pCur);
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+int sqlite3BtreeCursorSize(){
+  return sizeof(BtCursor);
+}
+
+
+
+/*
+** Close a cursor.  The read lock on the database file is released
+** when the last cursor is closed.
+*/
+int sqlite3BtreeCloseCursor(BtCursor *pCur){
+  Btree *pBtree = pCur->pBtree;
+  if( pBtree ){
+    BtShared *pBt = pCur->pBt;
+    sqlite3BtreeEnter(pBtree);
+    pBt->db = pBtree->db;
+    clearCursorPosition(pCur);
+    if( pCur->pPrev ){
+      pCur->pPrev->pNext = pCur->pNext;
+    }else{
+      pBt->pCursor = pCur->pNext;
+    }
+    if( pCur->pNext ){
+      pCur->pNext->pPrev = pCur->pPrev;
+    }
+    releasePage(pCur->pPage);
+    unlockBtreeIfUnused(pBt);
+    invalidateOverflowCache(pCur);
+    /* sqlite3_free(pCur); */
+    sqlite3BtreeLeave(pBtree);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Make a temporary cursor by filling in the fields of pTempCur.
+** The temporary cursor is not on the cursor list for the Btree.
+*/
+void sqlite3BtreeGetTempCursor(BtCursor *pCur, BtCursor *pTempCur){
+  assert( cursorHoldsMutex(pCur) );
+  memcpy(pTempCur, pCur, sizeof(*pCur));
+  pTempCur->pNext = 0;
+  pTempCur->pPrev = 0;
+  if( pTempCur->pPage ){
+    sqlite3PagerRef(pTempCur->pPage->pDbPage);
+  }
+}
+
+/*
+** Delete a temporary cursor such as was made by the CreateTemporaryCursor()
+** function above.
+*/
+void sqlite3BtreeReleaseTempCursor(BtCursor *pCur){
+  assert( cursorHoldsMutex(pCur) );
+  if( pCur->pPage ){
+    sqlite3PagerUnref(pCur->pPage->pDbPage);
+  }
+}
+
+/*
+** Make sure the BtCursor* given in the argument has a valid
+** BtCursor.info structure.  If it is not already valid, call
+** sqlite3BtreeParseCell() to fill it in.
+**
+** BtCursor.info is a cache of the information in the current cell.
+** Using this cache reduces the number of calls to sqlite3BtreeParseCell().
+**
+** 2007-06-25:  There is a bug in some versions of MSVC that cause the
+** compiler to crash when getCellInfo() is implemented as a macro.
+** But there is a measureable speed advantage to using the macro on gcc
+** (when less compiler optimizations like -Os or -O0 are used and the
+** compiler is not doing agressive inlining.)  So we use a real function
+** for MSVC and a macro for everything else.  Ticket #2457.
+*/
+#ifndef NDEBUG
+  static void assertCellInfo(BtCursor *pCur){
+    CellInfo info;
+    memset(&info, 0, sizeof(info));
+    sqlite3BtreeParseCell(pCur->pPage, pCur->idx, &info);
+    assert( memcmp(&info, &pCur->info, sizeof(info))==0 );
+  }
+#else
+  #define assertCellInfo(x)
+#endif
+#ifdef _MSC_VER
+  /* Use a real function in MSVC to work around bugs in that compiler. */
+  static void getCellInfo(BtCursor *pCur){
+    if( pCur->info.nSize==0 ){
+      sqlite3BtreeParseCell(pCur->pPage, pCur->idx, &pCur->info);
+      pCur->validNKey = 1;
+    }else{
+      assertCellInfo(pCur);
+    }
+  }
+#else /* if not _MSC_VER */
+  /* Use a macro in all other compilers so that the function is inlined */
+#define getCellInfo(pCur)                                               \
+  if( pCur->info.nSize==0 ){                                            \
+    sqlite3BtreeParseCell(pCur->pPage, pCur->idx, &pCur->info);         \
+    pCur->validNKey = 1;                                                \
+  }else{                                                                \
+    assertCellInfo(pCur);                                               \
+  }
+#endif /* _MSC_VER */
+
+/*
+** Set *pSize to the size of the buffer needed to hold the value of
+** the key for the current entry.  If the cursor is not pointing
+** to a valid entry, *pSize is set to 0. 
+**
+** For a table with the INTKEY flag set, this routine returns the key
+** itself, not the number of bytes in the key.
+*/
+int sqlite3BtreeKeySize(BtCursor *pCur, i64 *pSize){
+  int rc;
+
+  assert( cursorHoldsMutex(pCur) );
+  rc = restoreCursorPosition(pCur);
+  if( rc==SQLITE_OK ){
+    assert( pCur->eState==CURSOR_INVALID || pCur->eState==CURSOR_VALID );
+    if( pCur->eState==CURSOR_INVALID ){
+      *pSize = 0;
+    }else{
+      getCellInfo(pCur);
+      *pSize = pCur->info.nKey;
+    }
+  }
+  return rc;
+}
+
+/*
+** Set *pSize to the number of bytes of data in the entry the
+** cursor currently points to.  Always return SQLITE_OK.
+** Failure is not possible.  If the cursor is not currently
+** pointing to an entry (which can happen, for example, if
+** the database is empty) then *pSize is set to 0.
+*/
+int sqlite3BtreeDataSize(BtCursor *pCur, u32 *pSize){
+  int rc;
+
+  assert( cursorHoldsMutex(pCur) );
+  rc = restoreCursorPosition(pCur);
+  if( rc==SQLITE_OK ){
+    assert( pCur->eState==CURSOR_INVALID || pCur->eState==CURSOR_VALID );
+    if( pCur->eState==CURSOR_INVALID ){
+      /* Not pointing at a valid entry - set *pSize to 0. */
+      *pSize = 0;
+    }else{
+      getCellInfo(pCur);
+      *pSize = pCur->info.nData;
+    }
+  }
+  return rc;
+}
+
+/*
+** Given the page number of an overflow page in the database (parameter
+** ovfl), this function finds the page number of the next page in the 
+** linked list of overflow pages. If possible, it uses the auto-vacuum
+** pointer-map data instead of reading the content of page ovfl to do so. 
+**
+** If an error occurs an SQLite error code is returned. Otherwise:
+**
+** Unless pPgnoNext is NULL, the page number of the next overflow 
+** page in the linked list is written to *pPgnoNext. If page ovfl
+** is the last page in its linked list, *pPgnoNext is set to zero. 
+**
+** If ppPage is not NULL, *ppPage is set to the MemPage* handle
+** for page ovfl. The underlying pager page may have been requested
+** with the noContent flag set, so the page data accessable via
+** this handle may not be trusted.
+*/
+static int getOverflowPage(
+  BtShared *pBt, 
+  Pgno ovfl,                   /* Overflow page */
+  MemPage **ppPage,            /* OUT: MemPage handle */
+  Pgno *pPgnoNext              /* OUT: Next overflow page number */
+){
+  Pgno next = 0;
+  int rc;
+
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  /* One of these must not be NULL. Otherwise, why call this function? */
+  assert(ppPage || pPgnoNext);
+
+  /* If pPgnoNext is NULL, then this function is being called to obtain
+  ** a MemPage* reference only. No page-data is required in this case.
+  */
+  if( !pPgnoNext ){
+    return sqlite3BtreeGetPage(pBt, ovfl, ppPage, 1);
+  }
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+  /* Try to find the next page in the overflow list using the
+  ** autovacuum pointer-map pages. Guess that the next page in 
+  ** the overflow list is page number (ovfl+1). If that guess turns 
+  ** out to be wrong, fall back to loading the data of page 
+  ** number ovfl to determine the next page number.
+  */
+  if( pBt->autoVacuum ){
+    Pgno pgno;
+    Pgno iGuess = ovfl+1;
+    u8 eType;
+
+    while( PTRMAP_ISPAGE(pBt, iGuess) || iGuess==PENDING_BYTE_PAGE(pBt) ){
+      iGuess++;
+    }
+
+    if( iGuess<=pagerPagecount(pBt->pPager) ){
+      rc = ptrmapGet(pBt, iGuess, &eType, &pgno);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      if( eType==PTRMAP_OVERFLOW2 && pgno==ovfl ){
+        next = iGuess;
+      }
+    }
+  }
+#endif
+
+  if( next==0 || ppPage ){
+    MemPage *pPage = 0;
+
+    rc = sqlite3BtreeGetPage(pBt, ovfl, &pPage, next!=0);
+    assert(rc==SQLITE_OK || pPage==0);
+    if( next==0 && rc==SQLITE_OK ){
+      next = get4byte(pPage->aData);
+    }
+
+    if( ppPage ){
+      *ppPage = pPage;
+    }else{
+      releasePage(pPage);
+    }
+  }
+  *pPgnoNext = next;
+
+  return rc;
+}
+
+/*
+** Copy data from a buffer to a page, or from a page to a buffer.
+**
+** pPayload is a pointer to data stored on database page pDbPage.
+** If argument eOp is false, then nByte bytes of data are copied
+** from pPayload to the buffer pointed at by pBuf. If eOp is true,
+** then sqlite3PagerWrite() is called on pDbPage and nByte bytes
+** of data are copied from the buffer pBuf to pPayload.
+**
+** SQLITE_OK is returned on success, otherwise an error code.
+*/
+static int copyPayload(
+  void *pPayload,           /* Pointer to page data */
+  void *pBuf,               /* Pointer to buffer */
+  int nByte,                /* Number of bytes to copy */
+  int eOp,                  /* 0 -> copy from page, 1 -> copy to page */
+  DbPage *pDbPage           /* Page containing pPayload */
+){
+  if( eOp ){
+    /* Copy data from buffer to page (a write operation) */
+    int rc = sqlite3PagerWrite(pDbPage);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    memcpy(pPayload, pBuf, nByte);
+  }else{
+    /* Copy data from page to buffer (a read operation) */
+    memcpy(pBuf, pPayload, nByte);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** This function is used to read or overwrite payload information
+** for the entry that the pCur cursor is pointing to. If the eOp
+** parameter is 0, this is a read operation (data copied into
+** buffer pBuf). If it is non-zero, a write (data copied from
+** buffer pBuf).
+**
+** A total of "amt" bytes are read or written beginning at "offset".
+** Data is read to or from the buffer pBuf.
+**
+** This routine does not make a distinction between key and data.
+** It just reads or writes bytes from the payload area.  Data might 
+** appear on the main page or be scattered out on multiple overflow 
+** pages.
+**
+** If the BtCursor.isIncrblobHandle flag is set, and the current
+** cursor entry uses one or more overflow pages, this function
+** allocates space for and lazily popluates the overflow page-list 
+** cache array (BtCursor.aOverflow). Subsequent calls use this
+** cache to make seeking to the supplied offset more efficient.
+**
+** Once an overflow page-list cache has been allocated, it may be
+** invalidated if some other cursor writes to the same table, or if
+** the cursor is moved to a different row. Additionally, in auto-vacuum
+** mode, the following events may invalidate an overflow page-list cache.
+**
+**   * An incremental vacuum,
+**   * A commit in auto_vacuum="full" mode,
+**   * Creating a table (may require moving an overflow page).
+*/
+static int accessPayload(
+  BtCursor *pCur,      /* Cursor pointing to entry to read from */
+  int offset,          /* Begin reading this far into payload */
+  int amt,             /* Read this many bytes */
+  unsigned char *pBuf, /* Write the bytes into this buffer */ 
+  int skipKey,         /* offset begins at data if this is true */
+  int eOp              /* zero to read. non-zero to write. */
+){
+  unsigned char *aPayload;
+  int rc = SQLITE_OK;
+  u32 nKey;
+  int iIdx = 0;
+  MemPage *pPage = pCur->pPage;     /* Btree page of current cursor entry */
+  BtShared *pBt;                   /* Btree this cursor belongs to */
+
+  assert( pPage );
+  assert( pCur->eState==CURSOR_VALID );
+  assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
+  assert( offset>=0 );
+  assert( cursorHoldsMutex(pCur) );
+
+  getCellInfo(pCur);
+  aPayload = pCur->info.pCell + pCur->info.nHeader;
+  nKey = (pPage->intKey ? 0 : pCur->info.nKey);
+
+  if( skipKey ){
+    offset += nKey;
+  }
+  if( offset+amt > nKey+pCur->info.nData ){
+    /* Trying to read or write past the end of the data is an error */
+    return SQLITE_ERROR;
+  }
+
+  /* Check if data must be read/written to/from the btree page itself. */
+  if( offset<pCur->info.nLocal ){
+    int a = amt;
+    if( a+offset>pCur->info.nLocal ){
+      a = pCur->info.nLocal - offset;
+    }
+    rc = copyPayload(&aPayload[offset], pBuf, a, eOp, pPage->pDbPage);
+    offset = 0;
+    pBuf += a;
+    amt -= a;
+  }else{
+    offset -= pCur->info.nLocal;
+  }
+
+  pBt = pCur->pBt;
+  if( rc==SQLITE_OK && amt>0 ){
+    const int ovflSize = pBt->usableSize - 4;  /* Bytes content per ovfl page */
+    Pgno nextPage;
+
+    nextPage = get4byte(&aPayload[pCur->info.nLocal]);
+
+#ifndef SQLITE_OMIT_INCRBLOB
+    /* If the isIncrblobHandle flag is set and the BtCursor.aOverflow[]
+    ** has not been allocated, allocate it now. The array is sized at
+    ** one entry for each overflow page in the overflow chain. The
+    ** page number of the first overflow page is stored in aOverflow[0],
+    ** etc. A value of 0 in the aOverflow[] array means "not yet known"
+    ** (the cache is lazily populated).
+    */
+    if( pCur->isIncrblobHandle && !pCur->aOverflow ){
+      int nOvfl = (pCur->info.nPayload-pCur->info.nLocal+ovflSize-1)/ovflSize;
+      pCur->aOverflow = (Pgno *)sqlite3MallocZero(sizeof(Pgno)*nOvfl);
+      if( nOvfl && !pCur->aOverflow ){
+        rc = SQLITE_NOMEM;
+      }
+    }
+
+    /* If the overflow page-list cache has been allocated and the
+    ** entry for the first required overflow page is valid, skip
+    ** directly to it.
+    */
+    if( pCur->aOverflow && pCur->aOverflow[offset/ovflSize] ){
+      iIdx = (offset/ovflSize);
+      nextPage = pCur->aOverflow[iIdx];
+      offset = (offset%ovflSize);
+    }
+#endif
+
+    for( ; rc==SQLITE_OK && amt>0 && nextPage; iIdx++){
+
+#ifndef SQLITE_OMIT_INCRBLOB
+      /* If required, populate the overflow page-list cache. */
+      if( pCur->aOverflow ){
+        assert(!pCur->aOverflow[iIdx] || pCur->aOverflow[iIdx]==nextPage);
+        pCur->aOverflow[iIdx] = nextPage;
+      }
+#endif
+
+      if( offset>=ovflSize ){
+        /* The only reason to read this page is to obtain the page
+        ** number for the next page in the overflow chain. The page
+        ** data is not required. So first try to lookup the overflow
+        ** page-list cache, if any, then fall back to the getOverflowPage()
+        ** function.
+        */
+#ifndef SQLITE_OMIT_INCRBLOB
+        if( pCur->aOverflow && pCur->aOverflow[iIdx+1] ){
+          nextPage = pCur->aOverflow[iIdx+1];
+        } else 
+#endif
+          rc = getOverflowPage(pBt, nextPage, 0, &nextPage);
+        offset -= ovflSize;
+      }else{
+        /* Need to read this page properly. It contains some of the
+        ** range of data that is being read (eOp==0) or written (eOp!=0).
+        */
+        DbPage *pDbPage;
+        int a = amt;
+        rc = sqlite3PagerGet(pBt->pPager, nextPage, &pDbPage);
+        if( rc==SQLITE_OK ){
+          aPayload = sqlite3PagerGetData(pDbPage);
+          nextPage = get4byte(aPayload);
+          if( a + offset > ovflSize ){
+            a = ovflSize - offset;
+          }
+          rc = copyPayload(&aPayload[offset+4], pBuf, a, eOp, pDbPage);
+          sqlite3PagerUnref(pDbPage);
+          offset = 0;
+          amt -= a;
+          pBuf += a;
+        }
+      }
+    }
+  }
+
+  if( rc==SQLITE_OK && amt>0 ){
+    return SQLITE_CORRUPT_BKPT;
+  }
+  return rc;
+}
+
+/*
+** Read part of the key associated with cursor pCur.  Exactly
+** "amt" bytes will be transfered into pBuf[].  The transfer
+** begins at "offset".
+**
+** Return SQLITE_OK on success or an error code if anything goes
+** wrong.  An error is returned if "offset+amt" is larger than
+** the available payload.
+*/
+int sqlite3BtreeKey(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
+  int rc;
+
+  assert( cursorHoldsMutex(pCur) );
+  rc = restoreCursorPosition(pCur);
+  if( rc==SQLITE_OK ){
+    assert( pCur->eState==CURSOR_VALID );
+    assert( pCur->pPage!=0 );
+    if( pCur->pPage->intKey ){
+      return SQLITE_CORRUPT_BKPT;
+    }
+    assert( pCur->pPage->intKey==0 );
+    assert( pCur->idx>=0 && pCur->idx<pCur->pPage->nCell );
+    rc = accessPayload(pCur, offset, amt, (unsigned char*)pBuf, 0, 0);
+  }
+  return rc;
+}
+
+/*
+** Read part of the data associated with cursor pCur.  Exactly
+** "amt" bytes will be transfered into pBuf[].  The transfer
+** begins at "offset".
+**
+** Return SQLITE_OK on success or an error code if anything goes
+** wrong.  An error is returned if "offset+amt" is larger than
+** the available payload.
+*/
+int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
+  int rc;
+
+#ifndef SQLITE_OMIT_INCRBLOB
+  if ( pCur->eState==CURSOR_INVALID ){
+    return SQLITE_ABORT;
+  }
+#endif
+
+  assert( cursorHoldsMutex(pCur) );
+  rc = restoreCursorPosition(pCur);
+  if( rc==SQLITE_OK ){
+    assert( pCur->eState==CURSOR_VALID );
+    assert( pCur->pPage!=0 );
+    assert( pCur->idx>=0 && pCur->idx<pCur->pPage->nCell );
+    rc = accessPayload(pCur, offset, amt, pBuf, 1, 0);
+  }
+  return rc;
+}
+
+/*
+** Return a pointer to payload information from the entry that the 
+** pCur cursor is pointing to.  The pointer is to the beginning of
+** the key if skipKey==0 and it points to the beginning of data if
+** skipKey==1.  The number of bytes of available key/data is written
+** into *pAmt.  If *pAmt==0, then the value returned will not be
+** a valid pointer.
+**
+** This routine is an optimization.  It is common for the entire key
+** and data to fit on the local page and for there to be no overflow
+** pages.  When that is so, this routine can be used to access the
+** key and data without making a copy.  If the key and/or data spills
+** onto overflow pages, then accessPayload() must be used to reassembly
+** the key/data and copy it into a preallocated buffer.
+**
+** The pointer returned by this routine looks directly into the cached
+** page of the database.  The data might change or move the next time
+** any btree routine is called.
+*/
+static const unsigned char *fetchPayload(
+  BtCursor *pCur,      /* Cursor pointing to entry to read from */
+  int *pAmt,           /* Write the number of available bytes here */
+  int skipKey          /* read beginning at data if this is true */
+){
+  unsigned char *aPayload;
+  MemPage *pPage;
+  u32 nKey;
+  int nLocal;
+
+  assert( pCur!=0 && pCur->pPage!=0 );
+  assert( pCur->eState==CURSOR_VALID );
+  assert( cursorHoldsMutex(pCur) );
+  pPage = pCur->pPage;
+  assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
+  getCellInfo(pCur);
+  aPayload = pCur->info.pCell;
+  aPayload += pCur->info.nHeader;
+  if( pPage->intKey ){
+    nKey = 0;
+  }else{
+    nKey = pCur->info.nKey;
+  }
+  if( skipKey ){
+    aPayload += nKey;
+    nLocal = pCur->info.nLocal - nKey;
+  }else{
+    nLocal = pCur->info.nLocal;
+    if( nLocal>nKey ){
+      nLocal = nKey;
+    }
+  }
+  *pAmt = nLocal;
+  return aPayload;
+}
+
+
+/*
+** For the entry that cursor pCur is point to, return as
+** many bytes of the key or data as are available on the local
+** b-tree page.  Write the number of available bytes into *pAmt.
+**
+** The pointer returned is ephemeral.  The key/data may move
+** or be destroyed on the next call to any Btree routine,
+** including calls from other threads against the same cache.
+** Hence, a mutex on the BtShared should be held prior to calling
+** this routine.
+**
+** These routines is used to get quick access to key and data
+** in the common case where no overflow pages are used.
+*/
+const void *sqlite3BtreeKeyFetch(BtCursor *pCur, int *pAmt){
+  assert( cursorHoldsMutex(pCur) );
+  if( pCur->eState==CURSOR_VALID ){
+    return (const void*)fetchPayload(pCur, pAmt, 0);
+  }
+  return 0;
+}
+const void *sqlite3BtreeDataFetch(BtCursor *pCur, int *pAmt){
+  assert( cursorHoldsMutex(pCur) );
+  if( pCur->eState==CURSOR_VALID ){
+    return (const void*)fetchPayload(pCur, pAmt, 1);
+  }
+  return 0;
+}
+
+
+/*
+** Move the cursor down to a new child page.  The newPgno argument is the
+** page number of the child page to move to.
+*/
+static int moveToChild(BtCursor *pCur, u32 newPgno){
+  int rc;
+  MemPage *pNewPage;
+  MemPage *pOldPage;
+  BtShared *pBt = pCur->pBt;
+
+  assert( cursorHoldsMutex(pCur) );
+  assert( pCur->eState==CURSOR_VALID );
+  rc = getAndInitPage(pBt, newPgno, &pNewPage, pCur->pPage);
+  if( rc ) return rc;
+  pNewPage->idxParent = pCur->idx;
+  pOldPage = pCur->pPage;
+  pOldPage->idxShift = 0;
+  releasePage(pOldPage);
+  pCur->pPage = pNewPage;
+  pCur->idx = 0;
+  pCur->info.nSize = 0;
+  pCur->validNKey = 0;
+  if( pNewPage->nCell<1 ){
+    return SQLITE_CORRUPT_BKPT;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Return true if the page is the virtual root of its table.
+**
+** The virtual root page is the root page for most tables.  But
+** for the table rooted on page 1, sometime the real root page
+** is empty except for the right-pointer.  In such cases the
+** virtual root page is the page that the right-pointer of page
+** 1 is pointing to.
+*/
+int sqlite3BtreeIsRootPage(MemPage *pPage){
+  MemPage *pParent;
+
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  pParent = pPage->pParent;
+  if( pParent==0 ) return 1;
+  if( pParent->pgno>1 ) return 0;
+  if( get2byte(&pParent->aData[pParent->hdrOffset+3])==0 ) return 1;
+  return 0;
+}
+
+/*
+** Move the cursor up to the parent page.
+**
+** pCur->idx is set to the cell index that contains the pointer
+** to the page we are coming from.  If we are coming from the
+** right-most child page then pCur->idx is set to one more than
+** the largest cell index.
+*/
+void sqlite3BtreeMoveToParent(BtCursor *pCur){
+  MemPage *pParent;
+  MemPage *pPage;
+  int idxParent;
+
+  assert( cursorHoldsMutex(pCur) );
+  assert( pCur->eState==CURSOR_VALID );
+  pPage = pCur->pPage;
+  assert( pPage!=0 );
+  assert( !sqlite3BtreeIsRootPage(pPage) );
+  pParent = pPage->pParent;
+  assert( pParent!=0 );
+  idxParent = pPage->idxParent;
+  sqlite3PagerRef(pParent->pDbPage);
+  releasePage(pPage);
+  pCur->pPage = pParent;
+  pCur->info.nSize = 0;
+  pCur->validNKey = 0;
+  assert( pParent->idxShift==0 );
+  pCur->idx = idxParent;
+}
+
+/*
+** Move the cursor to the root page
+*/
+static int moveToRoot(BtCursor *pCur){
+  MemPage *pRoot;
+  int rc = SQLITE_OK;
+  Btree *p = pCur->pBtree;
+  BtShared *pBt = p->pBt;
+
+  assert( cursorHoldsMutex(pCur) );
+  assert( CURSOR_INVALID < CURSOR_REQUIRESEEK );
+  assert( CURSOR_VALID   < CURSOR_REQUIRESEEK );
+  assert( CURSOR_FAULT   > CURSOR_REQUIRESEEK );
+  if( pCur->eState>=CURSOR_REQUIRESEEK ){
+    if( pCur->eState==CURSOR_FAULT ){
+      return pCur->skip;
+    }
+    clearCursorPosition(pCur);
+  }
+  pRoot = pCur->pPage;
+  if( pRoot && pRoot->pgno==pCur->pgnoRoot ){
+    assert( pRoot->isInit );
+  }else{
+    if( 
+      SQLITE_OK!=(rc = getAndInitPage(pBt, pCur->pgnoRoot, &pRoot, 0))
+    ){
+      pCur->eState = CURSOR_INVALID;
+      return rc;
+    }
+    releasePage(pCur->pPage);
+    pCur->pPage = pRoot;
+  }
+  pCur->idx = 0;
+  pCur->info.nSize = 0;
+  pCur->atLast = 0;
+  pCur->validNKey = 0;
+  if( pRoot->nCell==0 && !pRoot->leaf ){
+    Pgno subpage;
+    assert( pRoot->pgno==1 );
+    subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]);
+    assert( subpage>0 );
+    pCur->eState = CURSOR_VALID;
+    rc = moveToChild(pCur, subpage);
+  }
+  pCur->eState = ((pCur->pPage->nCell>0)?CURSOR_VALID:CURSOR_INVALID);
+  return rc;
+}
+
+/*
+** Move the cursor down to the left-most leaf entry beneath the
+** entry to which it is currently pointing.
+**
+** The left-most leaf is the one with the smallest key - the first
+** in ascending order.
+*/
+static int moveToLeftmost(BtCursor *pCur){
+  Pgno pgno;
+  int rc = SQLITE_OK;
+  MemPage *pPage;
+
+  assert( cursorHoldsMutex(pCur) );
+  assert( pCur->eState==CURSOR_VALID );
+  while( rc==SQLITE_OK && !(pPage = pCur->pPage)->leaf ){
+    assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
+    pgno = get4byte(findCell(pPage, pCur->idx));
+    rc = moveToChild(pCur, pgno);
+  }
+  return rc;
+}
+
+/*
+** Move the cursor down to the right-most leaf entry beneath the
+** page to which it is currently pointing.  Notice the difference
+** between moveToLeftmost() and moveToRightmost().  moveToLeftmost()
+** finds the left-most entry beneath the *entry* whereas moveToRightmost()
+** finds the right-most entry beneath the *page*.
+**
+** The right-most entry is the one with the largest key - the last
+** key in ascending order.
+*/
+static int moveToRightmost(BtCursor *pCur){
+  Pgno pgno;
+  int rc = SQLITE_OK;
+  MemPage *pPage;
+
+  assert( cursorHoldsMutex(pCur) );
+  assert( pCur->eState==CURSOR_VALID );
+  while( rc==SQLITE_OK && !(pPage = pCur->pPage)->leaf ){
+    pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
+    pCur->idx = pPage->nCell;
+    rc = moveToChild(pCur, pgno);
+  }
+  if( rc==SQLITE_OK ){
+    pCur->idx = pPage->nCell - 1;
+    pCur->info.nSize = 0;
+    pCur->validNKey = 0;
+  }
+  return SQLITE_OK;
+}
+
+/* Move the cursor to the first entry in the table.  Return SQLITE_OK
+** on success.  Set *pRes to 0 if the cursor actually points to something
+** or set *pRes to 1 if the table is empty.
+*/
+int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){
+  int rc;
+
+  assert( cursorHoldsMutex(pCur) );
+  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
+  rc = moveToRoot(pCur);
+  if( rc==SQLITE_OK ){
+    if( pCur->eState==CURSOR_INVALID ){
+      assert( pCur->pPage->nCell==0 );
+      *pRes = 1;
+      rc = SQLITE_OK;
+    }else{
+      assert( pCur->pPage->nCell>0 );
+      *pRes = 0;
+      rc = moveToLeftmost(pCur);
+    }
+  }
+  return rc;
+}
+
+/* Move the cursor to the last entry in the table.  Return SQLITE_OK
+** on success.  Set *pRes to 0 if the cursor actually points to something
+** or set *pRes to 1 if the table is empty.
+*/
+int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
+  int rc;
+ 
+  assert( cursorHoldsMutex(pCur) );
+  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
+  rc = moveToRoot(pCur);
+  if( rc==SQLITE_OK ){
+    if( CURSOR_INVALID==pCur->eState ){
+      assert( pCur->pPage->nCell==0 );
+      *pRes = 1;
+    }else{
+      assert( pCur->eState==CURSOR_VALID );
+      *pRes = 0;
+      rc = moveToRightmost(pCur);
+      getCellInfo(pCur);
+      pCur->atLast = rc==SQLITE_OK;
+    }
+  }
+  return rc;
+}
+
+/* Move the cursor so that it points to an entry near the key 
+** specified by pKey/nKey/pUnKey. Return a success code.
+**
+** For INTKEY tables, only the nKey parameter is used.  pKey 
+** and pUnKey must be NULL.  For index tables, either pUnKey
+** must point to a key that has already been unpacked, or else
+** pKey/nKey describes a blob containing the key.
+**
+** If an exact match is not found, then the cursor is always
+** left pointing at a leaf page which would hold the entry if it
+** were present.  The cursor might point to an entry that comes
+** before or after the key.
+**
+** The result of comparing the key with the entry to which the
+** cursor is written to *pRes if pRes!=NULL.  The meaning of
+** this value is as follows:
+**
+**     *pRes<0      The cursor is left pointing at an entry that
+**                  is smaller than pKey or if the table is empty
+**                  and the cursor is therefore left point to nothing.
+**
+**     *pRes==0     The cursor is left pointing at an entry that
+**                  exactly matches pKey.
+**
+**     *pRes>0      The cursor is left pointing at an entry that
+**                  is larger than pKey.
+**
+*/
+int sqlite3BtreeMoveto(
+  BtCursor *pCur,        /* The cursor to be moved */
+  const void *pKey,      /* The key content for indices.  Not used by tables */
+  UnpackedRecord *pUnKey,/* Unpacked version of pKey */
+  i64 nKey,              /* Size of pKey.  Or the key for tables */
+  int biasRight,         /* If true, bias the search to the high end */
+  int *pRes              /* Search result flag */
+){
+  int rc;
+  char aSpace[200];
+
+  assert( cursorHoldsMutex(pCur) );
+  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
+
+  /* If the cursor is already positioned at the point we are trying
+  ** to move to, then just return without doing any work */
+  if( pCur->eState==CURSOR_VALID && pCur->validNKey && pCur->pPage->intKey ){
+    if( pCur->info.nKey==nKey ){
+      *pRes = 0;
+      return SQLITE_OK;
+    }
+    if( pCur->atLast && pCur->info.nKey<nKey ){
+      *pRes = -1;
+      return SQLITE_OK;
+    }
+  }
+
+
+  rc = moveToRoot(pCur);
+  if( rc ){
+    return rc;
+  }
+  assert( pCur->pPage );
+  assert( pCur->pPage->isInit );
+  if( pCur->eState==CURSOR_INVALID ){
+    *pRes = -1;
+    assert( pCur->pPage->nCell==0 );
+    return SQLITE_OK;
+  }
+  if( pCur->pPage->intKey ){
+    /* We are given an SQL table to search.  The key is the integer
+    ** rowid contained in nKey.  pKey and pUnKey should both be NULL */
+    assert( pUnKey==0 );
+    assert( pKey==0 );
+  }else if( pUnKey==0 ){
+    /* We are to search an SQL index using a key encoded as a blob.
+    ** The blob is found at pKey and is nKey bytes in length.  Unpack
+    ** this key so that we can use it. */
+    assert( pKey!=0 );
+    pUnKey = sqlite3VdbeRecordUnpack(pCur->pKeyInfo, nKey, pKey,
+                                   aSpace, sizeof(aSpace));
+    if( pUnKey==0 ) return SQLITE_NOMEM;
+  }else{
+    /* We are to search an SQL index using a key that is already unpacked
+    ** and handed to us in pUnKey. */
+    assert( pKey==0 );
+  }
+  for(;;){
+    int lwr, upr;
+    Pgno chldPg;
+    MemPage *pPage = pCur->pPage;
+    int c = -1;  /* pRes return if table is empty must be -1 */
+    lwr = 0;
+    upr = pPage->nCell-1;
+    if( !pPage->intKey && pUnKey==0 ){
+      rc = SQLITE_CORRUPT_BKPT;
+      goto moveto_finish;
+    }
+    if( biasRight ){
+      pCur->idx = upr;
+    }else{
+      pCur->idx = (upr+lwr)/2;
+    }
+    if( lwr<=upr ) for(;;){
+      void *pCellKey;
+      i64 nCellKey;
+      pCur->info.nSize = 0;
+      pCur->validNKey = 1;
+      if( pPage->intKey ){
+        u8 *pCell;
+        pCell = findCell(pPage, pCur->idx) + pPage->childPtrSize;
+        if( pPage->hasData ){
+          u32 dummy;
+          pCell += getVarint32(pCell, dummy);
+        }
+        getVarint(pCell, (u64*)&nCellKey);
+        if( nCellKey==nKey ){
+          c = 0;
+        }else if( nCellKey<nKey ){
+          c = -1;
+        }else{
+          assert( nCellKey>nKey );
+          c = +1;
+        }
+      }else{
+        int available;
+        pCellKey = (void *)fetchPayload(pCur, &available, 0);
+        nCellKey = pCur->info.nKey;
+        if( available>=nCellKey ){
+          c = sqlite3VdbeRecordCompare(nCellKey, pCellKey, pUnKey);
+        }else{
+          pCellKey = sqlite3Malloc( nCellKey );
+          if( pCellKey==0 ){
+            rc = SQLITE_NOMEM;
+            goto moveto_finish;
+          }
+          rc = sqlite3BtreeKey(pCur, 0, nCellKey, (void *)pCellKey);
+          c = sqlite3VdbeRecordCompare(nCellKey, pCellKey, pUnKey);
+          sqlite3_free(pCellKey);
+          if( rc ) goto moveto_finish;
+        }
+      }
+      if( c==0 ){
+        pCur->info.nKey = nCellKey;
+        if( pPage->intKey && !pPage->leaf ){
+          lwr = pCur->idx;
+          upr = lwr - 1;
+          break;
+        }else{
+          if( pRes ) *pRes = 0;
+          rc = SQLITE_OK;
+          goto moveto_finish;
+        }
+      }
+      if( c<0 ){
+        lwr = pCur->idx+1;
+      }else{
+        upr = pCur->idx-1;
+      }
+      if( lwr>upr ){
+        pCur->info.nKey = nCellKey;
+        break;
+      }
+      pCur->idx = (lwr+upr)/2;
+    }
+    assert( lwr==upr+1 );
+    assert( pPage->isInit );
+    if( pPage->leaf ){
+      chldPg = 0;
+    }else if( lwr>=pPage->nCell ){
+      chldPg = get4byte(&pPage->aData[pPage->hdrOffset+8]);
+    }else{
+      chldPg = get4byte(findCell(pPage, lwr));
+    }
+    if( chldPg==0 ){
+      assert( pCur->idx>=0 && pCur->idx<pCur->pPage->nCell );
+      if( pRes ) *pRes = c;
+      rc = SQLITE_OK;
+      goto moveto_finish;
+    }
+    pCur->idx = lwr;
+    pCur->info.nSize = 0;
+    pCur->validNKey = 0;
+    rc = moveToChild(pCur, chldPg);
+    if( rc ) goto moveto_finish;
+  }
+moveto_finish:
+  if( pKey ){
+    /* If we created our own unpacked key at the top of this
+    ** procedure, then destroy that key before returning. */
+    sqlite3VdbeDeleteUnpackedRecord(pUnKey);
+  }
+  return rc;
+}
+
+
+/*
+** Return TRUE if the cursor is not pointing at an entry of the table.
+**
+** TRUE will be returned after a call to sqlite3BtreeNext() moves
+** past the last entry in the table or sqlite3BtreePrev() moves past
+** the first entry.  TRUE is also returned if the table is empty.
+*/
+int sqlite3BtreeEof(BtCursor *pCur){
+  /* TODO: What if the cursor is in CURSOR_REQUIRESEEK but all table entries
+  ** have been deleted? This API will need to change to return an error code
+  ** as well as the boolean result value.
+  */
+  return (CURSOR_VALID!=pCur->eState);
+}
+
+/*
+** Return the database connection handle for a cursor.
+*/
+sqlite3 *sqlite3BtreeCursorDb(const BtCursor *pCur){
+  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
+  return pCur->pBtree->db;
+}
+
+/*
+** Advance the cursor to the next entry in the database.  If
+** successful then set *pRes=0.  If the cursor
+** was already pointing to the last entry in the database before
+** this routine was called, then set *pRes=1.
+*/
+int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
+  int rc;
+  MemPage *pPage;
+
+  assert( cursorHoldsMutex(pCur) );
+  rc = restoreCursorPosition(pCur);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+  assert( pRes!=0 );
+  pPage = pCur->pPage;
+  if( CURSOR_INVALID==pCur->eState ){
+    *pRes = 1;
+    return SQLITE_OK;
+  }
+  if( pCur->skip>0 ){
+    pCur->skip = 0;
+    *pRes = 0;
+    return SQLITE_OK;
+  }
+  pCur->skip = 0;
+
+  assert( pPage->isInit );
+  assert( pCur->idx<pPage->nCell );
+
+  pCur->idx++;
+  pCur->info.nSize = 0;
+  pCur->validNKey = 0;
+  if( pCur->idx>=pPage->nCell ){
+    if( !pPage->leaf ){
+      rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));
+      if( rc ) return rc;
+      rc = moveToLeftmost(pCur);
+      *pRes = 0;
+      return rc;
+    }
+    do{
+      if( sqlite3BtreeIsRootPage(pPage) ){
+        *pRes = 1;
+        pCur->eState = CURSOR_INVALID;
+        return SQLITE_OK;
+      }
+      sqlite3BtreeMoveToParent(pCur);
+      pPage = pCur->pPage;
+    }while( pCur->idx>=pPage->nCell );
+    *pRes = 0;
+    if( pPage->intKey ){
+      rc = sqlite3BtreeNext(pCur, pRes);
+    }else{
+      rc = SQLITE_OK;
+    }
+    return rc;
+  }
+  *pRes = 0;
+  if( pPage->leaf ){
+    return SQLITE_OK;
+  }
+  rc = moveToLeftmost(pCur);
+  return rc;
+}
+
+
+/*
+** Step the cursor to the back to the previous entry in the database.  If
+** successful then set *pRes=0.  If the cursor
+** was already pointing to the first entry in the database before
+** this routine was called, then set *pRes=1.
+*/
+int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
+  int rc;
+  Pgno pgno;
+  MemPage *pPage;
+
+  assert( cursorHoldsMutex(pCur) );
+  rc = restoreCursorPosition(pCur);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+  pCur->atLast = 0;
+  if( CURSOR_INVALID==pCur->eState ){
+    *pRes = 1;
+    return SQLITE_OK;
+  }
+  if( pCur->skip<0 ){
+    pCur->skip = 0;
+    *pRes = 0;
+    return SQLITE_OK;
+  }
+  pCur->skip = 0;
+
+  pPage = pCur->pPage;
+  assert( pPage->isInit );
+  assert( pCur->idx>=0 );
+  if( !pPage->leaf ){
+    pgno = get4byte( findCell(pPage, pCur->idx) );
+    rc = moveToChild(pCur, pgno);
+    if( rc ){
+      return rc;
+    }
+    rc = moveToRightmost(pCur);
+  }else{
+    while( pCur->idx==0 ){
+      if( sqlite3BtreeIsRootPage(pPage) ){
+        pCur->eState = CURSOR_INVALID;
+        *pRes = 1;
+        return SQLITE_OK;
+      }
+      sqlite3BtreeMoveToParent(pCur);
+      pPage = pCur->pPage;
+    }
+    pCur->idx--;
+    pCur->info.nSize = 0;
+    pCur->validNKey = 0;
+    if( pPage->intKey && !pPage->leaf ){
+      rc = sqlite3BtreePrevious(pCur, pRes);
+    }else{
+      rc = SQLITE_OK;
+    }
+  }
+  *pRes = 0;
+  return rc;
+}
+
+/*
+** Allocate a new page from the database file.
+**
+** The new page is marked as dirty.  (In other words, sqlite3PagerWrite()
+** has already been called on the new page.)  The new page has also
+** been referenced and the calling routine is responsible for calling
+** sqlite3PagerUnref() on the new page when it is done.
+**
+** SQLITE_OK is returned on success.  Any other return value indicates
+** an error.  *ppPage and *pPgno are undefined in the event of an error.
+** Do not invoke sqlite3PagerUnref() on *ppPage if an error is returned.
+**
+** If the "nearby" parameter is not 0, then a (feeble) effort is made to 
+** locate a page close to the page number "nearby".  This can be used in an
+** attempt to keep related pages close to each other in the database file,
+** which in turn can make database access faster.
+**
+** If the "exact" parameter is not 0, and the page-number nearby exists 
+** anywhere on the free-list, then it is guarenteed to be returned. This
+** is only used by auto-vacuum databases when allocating a new table.
+*/
+static int allocateBtreePage(
+  BtShared *pBt, 
+  MemPage **ppPage, 
+  Pgno *pPgno, 
+  Pgno nearby,
+  u8 exact
+){
+  MemPage *pPage1;
+  int rc;
+  int n;     /* Number of pages on the freelist */
+  int k;     /* Number of leaves on the trunk of the freelist */
+  MemPage *pTrunk = 0;
+  MemPage *pPrevTrunk = 0;
+
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  pPage1 = pBt->pPage1;
+  n = get4byte(&pPage1->aData[36]);
+  if( n>0 ){
+    /* There are pages on the freelist.  Reuse one of those pages. */
+    Pgno iTrunk;
+    u8 searchList = 0; /* If the free-list must be searched for 'nearby' */
+    
+    /* If the 'exact' parameter was true and a query of the pointer-map
+    ** shows that the page 'nearby' is somewhere on the free-list, then
+    ** the entire-list will be searched for that page.
+    */
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    if( exact && nearby<=pagerPagecount(pBt->pPager) ){
+      u8 eType;
+      assert( nearby>0 );
+      assert( pBt->autoVacuum );
+      rc = ptrmapGet(pBt, nearby, &eType, 0);
+      if( rc ) return rc;
+      if( eType==PTRMAP_FREEPAGE ){
+        searchList = 1;
+      }
+      *pPgno = nearby;
+    }
+#endif
+
+    /* Decrement the free-list count by 1. Set iTrunk to the index of the
+    ** first free-list trunk page. iPrevTrunk is initially 1.
+    */
+    rc = sqlite3PagerWrite(pPage1->pDbPage);
+    if( rc ) return rc;
+    put4byte(&pPage1->aData[36], n-1);
+
+    /* The code within this loop is run only once if the 'searchList' variable
+    ** is not true. Otherwise, it runs once for each trunk-page on the
+    ** free-list until the page 'nearby' is located.
+    */
+    do {
+      pPrevTrunk = pTrunk;
+      if( pPrevTrunk ){
+        iTrunk = get4byte(&pPrevTrunk->aData[0]);
+      }else{
+        iTrunk = get4byte(&pPage1->aData[32]);
+      }
+      rc = sqlite3BtreeGetPage(pBt, iTrunk, &pTrunk, 0);
+      if( rc ){
+        pTrunk = 0;
+        goto end_allocate_page;
+      }
+
+      k = get4byte(&pTrunk->aData[4]);
+      if( k==0 && !searchList ){
+        /* The trunk has no leaves and the list is not being searched. 
+        ** So extract the trunk page itself and use it as the newly 
+        ** allocated page */
+        assert( pPrevTrunk==0 );
+        rc = sqlite3PagerWrite(pTrunk->pDbPage);
+        if( rc ){
+          goto end_allocate_page;
+        }
+        *pPgno = iTrunk;
+        memcpy(&pPage1->aData[32], &pTrunk->aData[0], 4);
+        *ppPage = pTrunk;
+        pTrunk = 0;
+        TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));
+      }else if( k>pBt->usableSize/4 - 2 ){
+        /* Value of k is out of range.  Database corruption */
+        rc = SQLITE_CORRUPT_BKPT;
+        goto end_allocate_page;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+      }else if( searchList && nearby==iTrunk ){
+        /* The list is being searched and this trunk page is the page
+        ** to allocate, regardless of whether it has leaves.
+        */
+        assert( *pPgno==iTrunk );
+        *ppPage = pTrunk;
+        searchList = 0;
+        rc = sqlite3PagerWrite(pTrunk->pDbPage);
+        if( rc ){
+          goto end_allocate_page;
+        }
+        if( k==0 ){
+          if( !pPrevTrunk ){
+            memcpy(&pPage1->aData[32], &pTrunk->aData[0], 4);
+          }else{
+            memcpy(&pPrevTrunk->aData[0], &pTrunk->aData[0], 4);
+          }
+        }else{
+          /* The trunk page is required by the caller but it contains 
+          ** pointers to free-list leaves. The first leaf becomes a trunk
+          ** page in this case.
+          */
+          MemPage *pNewTrunk;
+          Pgno iNewTrunk = get4byte(&pTrunk->aData[8]);
+          rc = sqlite3BtreeGetPage(pBt, iNewTrunk, &pNewTrunk, 0);
+          if( rc!=SQLITE_OK ){
+            goto end_allocate_page;
+          }
+          rc = sqlite3PagerWrite(pNewTrunk->pDbPage);
+          if( rc!=SQLITE_OK ){
+            releasePage(pNewTrunk);
+            goto end_allocate_page;
+          }
+          memcpy(&pNewTrunk->aData[0], &pTrunk->aData[0], 4);
+          put4byte(&pNewTrunk->aData[4], k-1);
+          memcpy(&pNewTrunk->aData[8], &pTrunk->aData[12], (k-1)*4);
+          releasePage(pNewTrunk);
+          if( !pPrevTrunk ){
+            put4byte(&pPage1->aData[32], iNewTrunk);
+          }else{
+            rc = sqlite3PagerWrite(pPrevTrunk->pDbPage);
+            if( rc ){
+              goto end_allocate_page;
+            }
+            put4byte(&pPrevTrunk->aData[0], iNewTrunk);
+          }
+        }
+        pTrunk = 0;
+        TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));
+#endif
+      }else{
+        /* Extract a leaf from the trunk */
+        int closest;
+        Pgno iPage;
+        unsigned char *aData = pTrunk->aData;
+        rc = sqlite3PagerWrite(pTrunk->pDbPage);
+        if( rc ){
+          goto end_allocate_page;
+        }
+        if( nearby>0 ){
+          int i, dist;
+          closest = 0;
+          dist = get4byte(&aData[8]) - nearby;
+          if( dist<0 ) dist = -dist;
+          for(i=1; i<k; i++){
+            int d2 = get4byte(&aData[8+i*4]) - nearby;
+            if( d2<0 ) d2 = -d2;
+            if( d2<dist ){
+              closest = i;
+              dist = d2;
+            }
+          }
+        }else{
+          closest = 0;
+        }
+
+        iPage = get4byte(&aData[8+closest*4]);
+        if( !searchList || iPage==nearby ){
+          int nPage;
+          *pPgno = iPage;
+          nPage = pagerPagecount(pBt->pPager);
+          if( *pPgno>nPage ){
+            /* Free page off the end of the file */
+            rc = SQLITE_CORRUPT_BKPT;
+            goto end_allocate_page;
+          }
+          TRACE(("ALLOCATE: %d was leaf %d of %d on trunk %d"
+                 ": %d more free pages\n",
+                 *pPgno, closest+1, k, pTrunk->pgno, n-1));
+          if( closest<k-1 ){
+            memcpy(&aData[8+closest*4], &aData[4+k*4], 4);
+          }
+          put4byte(&aData[4], k-1);
+          rc = sqlite3BtreeGetPage(pBt, *pPgno, ppPage, 1);
+          if( rc==SQLITE_OK ){
+            sqlite3PagerDontRollback((*ppPage)->pDbPage);
+            rc = sqlite3PagerWrite((*ppPage)->pDbPage);
+            if( rc!=SQLITE_OK ){
+              releasePage(*ppPage);
+            }
+          }
+          searchList = 0;
+        }
+      }
+      releasePage(pPrevTrunk);
+      pPrevTrunk = 0;
+    }while( searchList );
+  }else{
+    /* There are no pages on the freelist, so create a new page at the
+    ** end of the file */
+    int nPage = pagerPagecount(pBt->pPager);
+    *pPgno = nPage + 1;
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    if( pBt->nTrunc ){
+      /* An incr-vacuum has already run within this transaction. So the
+      ** page to allocate is not from the physical end of the file, but
+      ** at pBt->nTrunc. 
+      */
+      *pPgno = pBt->nTrunc+1;
+      if( *pPgno==PENDING_BYTE_PAGE(pBt) ){
+        (*pPgno)++;
+      }
+    }
+    if( pBt->autoVacuum && PTRMAP_ISPAGE(pBt, *pPgno) ){
+      /* If *pPgno refers to a pointer-map page, allocate two new pages
+      ** at the end of the file instead of one. The first allocated page
+      ** becomes a new pointer-map page, the second is used by the caller.
+      */
+      TRACE(("ALLOCATE: %d from end of file (pointer-map page)\n", *pPgno));
+      assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
+      (*pPgno)++;
+      if( *pPgno==PENDING_BYTE_PAGE(pBt) ){ (*pPgno)++; }
+    }
+    if( pBt->nTrunc ){
+      pBt->nTrunc = *pPgno;
+    }
+#endif
+
+    assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
+    rc = sqlite3BtreeGetPage(pBt, *pPgno, ppPage, 0);
+    if( rc ) return rc;
+    rc = sqlite3PagerWrite((*ppPage)->pDbPage);
+    if( rc!=SQLITE_OK ){
+      releasePage(*ppPage);
+    }
+    TRACE(("ALLOCATE: %d from end of file\n", *pPgno));
+  }
+
+  assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
+
+end_allocate_page:
+  releasePage(pTrunk);
+  releasePage(pPrevTrunk);
+  return rc;
+}
+
+/*
+** Add a page of the database file to the freelist.
+**
+** sqlite3PagerUnref() is NOT called for pPage.
+*/
+static int freePage(MemPage *pPage){
+  BtShared *pBt = pPage->pBt;
+  MemPage *pPage1 = pBt->pPage1;
+  int rc, n, k;
+
+  /* Prepare the page for freeing */
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  assert( pPage->pgno>1 );
+  pPage->isInit = 0;
+  releasePage(pPage->pParent);
+  pPage->pParent = 0;
+
+  /* Increment the free page count on pPage1 */
+  rc = sqlite3PagerWrite(pPage1->pDbPage);
+  if( rc ) return rc;
+  n = get4byte(&pPage1->aData[36]);
+  put4byte(&pPage1->aData[36], n+1);
+
+#ifdef SQLITE_SECURE_DELETE
+  /* If the SQLITE_SECURE_DELETE compile-time option is enabled, then
+  ** always fully overwrite deleted information with zeros.
+  */
+  rc = sqlite3PagerWrite(pPage->pDbPage);
+  if( rc ) return rc;
+  memset(pPage->aData, 0, pPage->pBt->pageSize);
+#endif
+
+  /* If the database supports auto-vacuum, write an entry in the pointer-map
+  ** to indicate that the page is free.
+  */
+  if( ISAUTOVACUUM ){
+    rc = ptrmapPut(pBt, pPage->pgno, PTRMAP_FREEPAGE, 0);
+    if( rc ) return rc;
+  }
+
+  if( n==0 ){
+    /* This is the first free page */
+    rc = sqlite3PagerWrite(pPage->pDbPage);
+    if( rc ) return rc;
+    memset(pPage->aData, 0, 8);
+    put4byte(&pPage1->aData[32], pPage->pgno);
+    TRACE(("FREE-PAGE: %d first\n", pPage->pgno));
+  }else{
+    /* Other free pages already exist.  Retrive the first trunk page
+    ** of the freelist and find out how many leaves it has. */
+    MemPage *pTrunk;
+    rc = sqlite3BtreeGetPage(pBt, get4byte(&pPage1->aData[32]), &pTrunk, 0);
+    if( rc ) return rc;
+    k = get4byte(&pTrunk->aData[4]);
+    if( k>=pBt->usableSize/4 - 8 ){
+      /* The trunk is full.  Turn the page being freed into a new
+      ** trunk page with no leaves.
+      **
+      ** Note that the trunk page is not really full until it contains
+      ** usableSize/4 - 2 entries, not usableSize/4 - 8 entries as we have
+      ** coded.  But due to a coding error in versions of SQLite prior to
+      ** 3.6.0, databases with freelist trunk pages holding more than
+      ** usableSize/4 - 8 entries will be reported as corrupt.  In order
+      ** to maintain backwards compatibility with older versions of SQLite,
+      ** we will contain to restrict the number of entries to usableSize/4 - 8
+      ** for now.  At some point in the future (once everyone has upgraded
+      ** to 3.6.0 or later) we should consider fixing the conditional above
+      ** to read "usableSize/4-2" instead of "usableSize/4-8".
+      */
+      rc = sqlite3PagerWrite(pPage->pDbPage);
+      if( rc==SQLITE_OK ){
+        put4byte(pPage->aData, pTrunk->pgno);
+        put4byte(&pPage->aData[4], 0);
+        put4byte(&pPage1->aData[32], pPage->pgno);
+        TRACE(("FREE-PAGE: %d new trunk page replacing %d\n",
+                pPage->pgno, pTrunk->pgno));
+      }
+    }else if( k<0 ){
+      rc = SQLITE_CORRUPT;
+    }else{
+      /* Add the newly freed page as a leaf on the current trunk */
+      rc = sqlite3PagerWrite(pTrunk->pDbPage);
+      if( rc==SQLITE_OK ){
+        put4byte(&pTrunk->aData[4], k+1);
+        put4byte(&pTrunk->aData[8+k*4], pPage->pgno);
+#ifndef SQLITE_SECURE_DELETE
+        sqlite3PagerDontWrite(pPage->pDbPage);
+#endif
+      }
+      TRACE(("FREE-PAGE: %d leaf on trunk page %d\n",pPage->pgno,pTrunk->pgno));
+    }
+    releasePage(pTrunk);
+  }
+  return rc;
+}
+
+/*
+** Free any overflow pages associated with the given Cell.
+*/
+static int clearCell(MemPage *pPage, unsigned char *pCell){
+  BtShared *pBt = pPage->pBt;
+  CellInfo info;
+  Pgno ovflPgno;
+  int rc;
+  int nOvfl;
+  int ovflPageSize;
+
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  sqlite3BtreeParseCellPtr(pPage, pCell, &info);
+  if( info.iOverflow==0 ){
+    return SQLITE_OK;  /* No overflow pages. Return without doing anything */
+  }
+  ovflPgno = get4byte(&pCell[info.iOverflow]);
+  ovflPageSize = pBt->usableSize - 4;
+  nOvfl = (info.nPayload - info.nLocal + ovflPageSize - 1)/ovflPageSize;
+  assert( ovflPgno==0 || nOvfl>0 );
+  while( nOvfl-- ){
+    MemPage *pOvfl;
+    if( ovflPgno==0 || ovflPgno>pagerPagecount(pBt->pPager) ){
+      return SQLITE_CORRUPT_BKPT;
+    }
+
+    rc = getOverflowPage(pBt, ovflPgno, &pOvfl, (nOvfl==0)?0:&ovflPgno);
+    if( rc ) return rc;
+    rc = freePage(pOvfl);
+    sqlite3PagerUnref(pOvfl->pDbPage);
+    if( rc ) return rc;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Create the byte sequence used to represent a cell on page pPage
+** and write that byte sequence into pCell[].  Overflow pages are
+** allocated and filled in as necessary.  The calling procedure
+** is responsible for making sure sufficient space has been allocated
+** for pCell[].
+**
+** Note that pCell does not necessary need to point to the pPage->aData
+** area.  pCell might point to some temporary storage.  The cell will
+** be constructed in this temporary area then copied into pPage->aData
+** later.
+*/
+static int fillInCell(
+  MemPage *pPage,                /* The page that contains the cell */
+  unsigned char *pCell,          /* Complete text of the cell */
+  const void *pKey, i64 nKey,    /* The key */
+  const void *pData,int nData,   /* The data */
+  int nZero,                     /* Extra zero bytes to append to pData */
+  int *pnSize                    /* Write cell size here */
+){
+  int nPayload;
+  const u8 *pSrc;
+  int nSrc, n, rc;
+  int spaceLeft;
+  MemPage *pOvfl = 0;
+  MemPage *pToRelease = 0;
+  unsigned char *pPrior;
+  unsigned char *pPayload;
+  BtShared *pBt = pPage->pBt;
+  Pgno pgnoOvfl = 0;
+  int nHeader;
+  CellInfo info;
+
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+
+  /* Fill in the header. */
+  nHeader = 0;
+  if( !pPage->leaf ){
+    nHeader += 4;
+  }
+  if( pPage->hasData ){
+    nHeader += putVarint(&pCell[nHeader], nData+nZero);
+  }else{
+    nData = nZero = 0;
+  }
+  nHeader += putVarint(&pCell[nHeader], *(u64*)&nKey);
+  sqlite3BtreeParseCellPtr(pPage, pCell, &info);
+  assert( info.nHeader==nHeader );
+  assert( info.nKey==nKey );
+  assert( info.nData==nData+nZero );
+  
+  /* Fill in the payload */
+  nPayload = nData + nZero;
+  if( pPage->intKey ){
+    pSrc = pData;
+    nSrc = nData;
+    nData = 0;
+  }else{
+    nPayload += nKey;
+    pSrc = pKey;
+    nSrc = nKey;
+  }
+  *pnSize = info.nSize;
+  spaceLeft = info.nLocal;
+  pPayload = &pCell[nHeader];
+  pPrior = &pCell[info.iOverflow];
+
+  while( nPayload>0 ){
+    if( spaceLeft==0 ){
+      int isExact = 0;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+      Pgno pgnoPtrmap = pgnoOvfl; /* Overflow page pointer-map entry page */
+      if( pBt->autoVacuum ){
+        do{
+          pgnoOvfl++;
+        } while( 
+          PTRMAP_ISPAGE(pBt, pgnoOvfl) || pgnoOvfl==PENDING_BYTE_PAGE(pBt) 
+        );
+        if( pgnoOvfl>1 ){
+          /* isExact = 1; */
+        }
+      }
+#endif
+      rc = allocateBtreePage(pBt, &pOvfl, &pgnoOvfl, pgnoOvfl, isExact);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+      /* If the database supports auto-vacuum, and the second or subsequent
+      ** overflow page is being allocated, add an entry to the pointer-map
+      ** for that page now. 
+      **
+      ** If this is the first overflow page, then write a partial entry 
+      ** to the pointer-map. If we write nothing to this pointer-map slot,
+      ** then the optimistic overflow chain processing in clearCell()
+      ** may misinterpret the uninitialised values and delete the
+      ** wrong pages from the database.
+      */
+      if( pBt->autoVacuum && rc==SQLITE_OK ){
+        u8 eType = (pgnoPtrmap?PTRMAP_OVERFLOW2:PTRMAP_OVERFLOW1);
+        rc = ptrmapPut(pBt, pgnoOvfl, eType, pgnoPtrmap);
+        if( rc ){
+          releasePage(pOvfl);
+        }
+      }
+#endif
+      if( rc ){
+        releasePage(pToRelease);
+        return rc;
+      }
+      put4byte(pPrior, pgnoOvfl);
+      releasePage(pToRelease);
+      pToRelease = pOvfl;
+      pPrior = pOvfl->aData;
+      put4byte(pPrior, 0);
+      pPayload = &pOvfl->aData[4];
+      spaceLeft = pBt->usableSize - 4;
+    }
+    n = nPayload;
+    if( n>spaceLeft ) n = spaceLeft;
+    if( nSrc>0 ){
+      if( n>nSrc ) n = nSrc;
+      assert( pSrc );
+      memcpy(pPayload, pSrc, n);
+    }else{
+      memset(pPayload, 0, n);
+    }
+    nPayload -= n;
+    pPayload += n;
+    pSrc += n;
+    nSrc -= n;
+    spaceLeft -= n;
+    if( nSrc==0 ){
+      nSrc = nData;
+      pSrc = pData;
+    }
+  }
+  releasePage(pToRelease);
+  return SQLITE_OK;
+}
+
+
+/*
+** Change the MemPage.pParent pointer on the page whose number is
+** given in the second argument so that MemPage.pParent holds the
+** pointer in the third argument.
+**
+** If the final argument, updatePtrmap, is non-zero and the database
+** is an auto-vacuum database, then the pointer-map entry for pgno
+** is updated.
+*/
+static int reparentPage(
+  BtShared *pBt,                /* B-Tree structure */
+  Pgno pgno,                    /* Page number of child being adopted */
+  MemPage *pNewParent,          /* New parent of pgno */
+  int idx,                      /* Index of child page pgno in pNewParent */
+  int updatePtrmap              /* If true, update pointer-map for pgno */
+){
+  MemPage *pThis;
+  DbPage *pDbPage;
+
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  assert( pNewParent!=0 );
+  if( pgno==0 ) return SQLITE_OK;
+  assert( pBt->pPager!=0 );
+  pDbPage = sqlite3PagerLookup(pBt->pPager, pgno);
+  if( pDbPage ){
+    pThis = (MemPage *)sqlite3PagerGetExtra(pDbPage);
+    if( pThis->isInit ){
+      assert( pThis->aData==sqlite3PagerGetData(pDbPage) );
+      if( pThis->pParent!=pNewParent ){
+        if( pThis->pParent ) sqlite3PagerUnref(pThis->pParent->pDbPage);
+        pThis->pParent = pNewParent;
+        sqlite3PagerRef(pNewParent->pDbPage);
+      }
+      pThis->idxParent = idx;
+    }
+    sqlite3PagerUnref(pDbPage);
+  }
+
+  if( ISAUTOVACUUM && updatePtrmap ){
+    return ptrmapPut(pBt, pgno, PTRMAP_BTREE, pNewParent->pgno);
+  }
+
+#ifndef NDEBUG
+  /* If the updatePtrmap flag was clear, assert that the entry in the
+  ** pointer-map is already correct.
+  */
+  if( ISAUTOVACUUM ){
+    pDbPage = sqlite3PagerLookup(pBt->pPager,PTRMAP_PAGENO(pBt,pgno));
+    if( pDbPage ){
+      u8 eType;
+      Pgno ii;
+      int rc = ptrmapGet(pBt, pgno, &eType, &ii);
+      assert( rc==SQLITE_OK && ii==pNewParent->pgno && eType==PTRMAP_BTREE );
+      sqlite3PagerUnref(pDbPage);
+    }
+  }
+#endif
+
+  return SQLITE_OK;
+}
+
+
+
+/*
+** Change the pParent pointer of all children of pPage to point back
+** to pPage.
+**
+** In other words, for every child of pPage, invoke reparentPage()
+** to make sure that each child knows that pPage is its parent.
+**
+** This routine gets called after you memcpy() one page into
+** another.
+**
+** If updatePtrmap is true, then the pointer-map entries for all child
+** pages of pPage are updated.
+*/
+static int reparentChildPages(MemPage *pPage, int updatePtrmap){
+  int rc = SQLITE_OK;
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  if( !pPage->leaf ){
+    int i;
+    BtShared *pBt = pPage->pBt;
+    Pgno iRight = get4byte(&pPage->aData[pPage->hdrOffset+8]);
+
+    for(i=0; i<pPage->nCell; i++){
+      u8 *pCell = findCell(pPage, i);
+      rc = reparentPage(pBt, get4byte(pCell), pPage, i, updatePtrmap);
+      if( rc!=SQLITE_OK ) return rc;
+    }
+    rc = reparentPage(pBt, iRight, pPage, i, updatePtrmap);
+    pPage->idxShift = 0;
+  }
+  return rc;
+}
+
+/*
+** Remove the i-th cell from pPage.  This routine effects pPage only.
+** The cell content is not freed or deallocated.  It is assumed that
+** the cell content has been copied someplace else.  This routine just
+** removes the reference to the cell from pPage.
+**
+** "sz" must be the number of bytes in the cell.
+*/
+static void dropCell(MemPage *pPage, int idx, int sz){
+  int i;          /* Loop counter */
+  int pc;         /* Offset to cell content of cell being deleted */
+  u8 *data;       /* pPage->aData */
+  u8 *ptr;        /* Used to move bytes around within data[] */
+
+  assert( idx>=0 && idx<pPage->nCell );
+  assert( sz==cellSize(pPage, idx) );
+  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  data = pPage->aData;
+  ptr = &data[pPage->cellOffset + 2*idx];
+  pc = get2byte(ptr);
+  assert( pc>10 && pc+sz<=pPage->pBt->usableSize );
+  freeSpace(pPage, pc, sz);
+  for(i=idx+1; i<pPage->nCell; i++, ptr+=2){
+    ptr[0] = ptr[2];
+    ptr[1] = ptr[3];
+  }
+  pPage->nCell--;
+  put2byte(&data[pPage->hdrOffset+3], pPage->nCell);
+  pPage->nFree += 2;
+  pPage->idxShift = 1;
+}
+
+/*
+** Insert a new cell on pPage at cell index "i".  pCell points to the
+** content of the cell.
+**
+** If the cell content will fit on the page, then put it there.  If it
+** will not fit, then make a copy of the cell content into pTemp if
+** pTemp is not null.  Regardless of pTemp, allocate a new entry
+** in pPage->aOvfl[] and make it point to the cell content (either
+** in pTemp or the original pCell) and also record its index. 
+** Allocating a new entry in pPage->aCell[] implies that 
+** pPage->nOverflow is incremented.
+**
+** If nSkip is non-zero, then do not copy the first nSkip bytes of the
+** cell. The caller will overwrite them after this function returns. If
+** nSkip is non-zero, then pCell may not point to an invalid memory location 
+** (but pCell+nSkip is always valid).
+*/
+static int insertCell(
+  MemPage *pPage,   /* Page into which we are copying */
+  int i,            /* New cell becomes the i-th cell of the page */
+  u8 *pCell,        /* Content of the new cell */
+  int sz,           /* Bytes of content in pCell */
+  u8 *pTemp,        /* Temp storage space for pCell, if needed */
+  u8 nSkip          /* Do not write the first nSkip bytes of the cell */
+){
+  int idx;          /* Where to write new cell content in data[] */
+  int j;            /* Loop counter */
+  int top;          /* First byte of content for any cell in data[] */
+  int end;          /* First byte past the last cell pointer in data[] */
+  int ins;          /* Index in data[] where new cell pointer is inserted */
+  int hdr;          /* Offset into data[] of the page header */
+  int cellOffset;   /* Address of first cell pointer in data[] */
+  u8 *data;         /* The content of the whole page */
+  u8 *ptr;          /* Used for moving information around in data[] */
+
+  assert( i>=0 && i<=pPage->nCell+pPage->nOverflow );
+  assert( sz==cellSizePtr(pPage, pCell) );
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  if( pPage->nOverflow || sz+2>pPage->nFree ){
+    if( pTemp ){
+      memcpy(pTemp+nSkip, pCell+nSkip, sz-nSkip);
+      pCell = pTemp;
+    }
+    j = pPage->nOverflow++;
+    assert( j<sizeof(pPage->aOvfl)/sizeof(pPage->aOvfl[0]) );
+    pPage->aOvfl[j].pCell = pCell;
+    pPage->aOvfl[j].idx = i;
+    pPage->nFree = 0;
+  }else{
+    int rc = sqlite3PagerWrite(pPage->pDbPage);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    assert( sqlite3PagerIswriteable(pPage->pDbPage) );
+    data = pPage->aData;
+    hdr = pPage->hdrOffset;
+    top = get2byte(&data[hdr+5]);
+    cellOffset = pPage->cellOffset;
+    end = cellOffset + 2*pPage->nCell + 2;
+    ins = cellOffset + 2*i;
+    if( end > top - sz ){
+      defragmentPage(pPage);
+      top = get2byte(&data[hdr+5]);
+      assert( end + sz <= top );
+    }
+    idx = allocateSpace(pPage, sz);
+    assert( idx>0 );
+    assert( end <= get2byte(&data[hdr+5]) );
+    pPage->nCell++;
+    pPage->nFree -= 2;
+    memcpy(&data[idx+nSkip], pCell+nSkip, sz-nSkip);
+    for(j=end-2, ptr=&data[j]; j>ins; j-=2, ptr-=2){
+      ptr[0] = ptr[-2];
+      ptr[1] = ptr[-1];
+    }
+    put2byte(&data[ins], idx);
+    put2byte(&data[hdr+3], pPage->nCell);
+    pPage->idxShift = 1;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    if( pPage->pBt->autoVacuum ){
+      /* The cell may contain a pointer to an overflow page. If so, write
+      ** the entry for the overflow page into the pointer map.
+      */
+      CellInfo info;
+      sqlite3BtreeParseCellPtr(pPage, pCell, &info);
+      assert( (info.nData+(pPage->intKey?0:info.nKey))==info.nPayload );
+      if( (info.nData+(pPage->intKey?0:info.nKey))>info.nLocal ){
+        Pgno pgnoOvfl = get4byte(&pCell[info.iOverflow]);
+        rc = ptrmapPut(pPage->pBt, pgnoOvfl, PTRMAP_OVERFLOW1, pPage->pgno);
+        if( rc!=SQLITE_OK ) return rc;
+      }
+    }
+#endif
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Add a list of cells to a page.  The page should be initially empty.
+** The cells are guaranteed to fit on the page.
+*/
+static void assemblePage(
+  MemPage *pPage,   /* The page to be assemblied */
+  int nCell,        /* The number of cells to add to this page */
+  u8 **apCell,      /* Pointers to cell bodies */
+  u16 *aSize        /* Sizes of the cells */
+){
+  int i;            /* Loop counter */
+  int totalSize;    /* Total size of all cells */
+  int hdr;          /* Index of page header */
+  int cellptr;      /* Address of next cell pointer */
+  int cellbody;     /* Address of next cell body */
+  u8 *data;         /* Data for the page */
+
+  assert( pPage->nOverflow==0 );
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  totalSize = 0;
+  for(i=0; i<nCell; i++){
+    totalSize += aSize[i];
+  }
+  assert( totalSize+2*nCell<=pPage->nFree );
+  assert( pPage->nCell==0 );
+  cellptr = pPage->cellOffset;
+  data = pPage->aData;
+  hdr = pPage->hdrOffset;
+  put2byte(&data[hdr+3], nCell);
+  if( nCell ){
+    cellbody = allocateSpace(pPage, totalSize);
+    assert( cellbody>0 );
+    assert( pPage->nFree >= 2*nCell );
+    pPage->nFree -= 2*nCell;
+    for(i=0; i<nCell; i++){
+      put2byte(&data[cellptr], cellbody);
+      memcpy(&data[cellbody], apCell[i], aSize[i]);
+      cellptr += 2;
+      cellbody += aSize[i];
+    }
+    assert( cellbody==pPage->pBt->usableSize );
+  }
+  pPage->nCell = nCell;
+}
+
+/*
+** The following parameters determine how many adjacent pages get involved
+** in a balancing operation.  NN is the number of neighbors on either side
+** of the page that participate in the balancing operation.  NB is the
+** total number of pages that participate, including the target page and
+** NN neighbors on either side.
+**
+** The minimum value of NN is 1 (of course).  Increasing NN above 1
+** (to 2 or 3) gives a modest improvement in SELECT and DELETE performance
+** in exchange for a larger degradation in INSERT and UPDATE performance.
+** The value of NN appears to give the best results overall.
+*/
+#define NN 1             /* Number of neighbors on either side of pPage */
+#define NB (NN*2+1)      /* Total pages involved in the balance */
+
+/* Forward reference */
+static int balance(MemPage*, int);
+
+#ifndef SQLITE_OMIT_QUICKBALANCE
+/*
+** This version of balance() handles the common special case where
+** a new entry is being inserted on the extreme right-end of the
+** tree, in other words, when the new entry will become the largest
+** entry in the tree.
+**
+** Instead of trying balance the 3 right-most leaf pages, just add
+** a new page to the right-hand side and put the one new entry in
+** that page.  This leaves the right side of the tree somewhat
+** unbalanced.  But odds are that we will be inserting new entries
+** at the end soon afterwards so the nearly empty page will quickly
+** fill up.  On average.
+**
+** pPage is the leaf page which is the right-most page in the tree.
+** pParent is its parent.  pPage must have a single overflow entry
+** which is also the right-most entry on the page.
+*/
+static int balance_quick(MemPage *pPage, MemPage *pParent){
+  int rc;
+  MemPage *pNew;
+  Pgno pgnoNew;
+  u8 *pCell;
+  u16 szCell;
+  CellInfo info;
+  BtShared *pBt = pPage->pBt;
+  int parentIdx = pParent->nCell;   /* pParent new divider cell index */
+  int parentSize;                   /* Size of new divider cell */
+  u8 parentCell[64];                /* Space for the new divider cell */
+
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+
+  /* Allocate a new page. Insert the overflow cell from pPage
+  ** into it. Then remove the overflow cell from pPage.
+  */
+  rc = allocateBtreePage(pBt, &pNew, &pgnoNew, 0, 0);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+  pCell = pPage->aOvfl[0].pCell;
+  szCell = cellSizePtr(pPage, pCell);
+  zeroPage(pNew, pPage->aData[0]);
+  assemblePage(pNew, 1, &pCell, &szCell);
+  pPage->nOverflow = 0;
+
+  /* Set the parent of the newly allocated page to pParent. */
+  pNew->pParent = pParent;
+  sqlite3PagerRef(pParent->pDbPage);
+
+  /* pPage is currently the right-child of pParent. Change this
+  ** so that the right-child is the new page allocated above and
+  ** pPage is the next-to-right child. 
+  **
+  ** Ignore the return value of the call to fillInCell(). fillInCell()
+  ** may only return other than SQLITE_OK if it is required to allocate
+  ** one or more overflow pages. Since an internal table B-Tree cell 
+  ** may never spill over onto an overflow page (it is a maximum of 
+  ** 13 bytes in size), it is not neccessary to check the return code.
+  **
+  ** Similarly, the insertCell() function cannot fail if the page
+  ** being inserted into is already writable and the cell does not 
+  ** contain an overflow pointer. So ignore this return code too.
+  */
+  assert( pPage->nCell>0 );
+  pCell = findCell(pPage, pPage->nCell-1);
+  sqlite3BtreeParseCellPtr(pPage, pCell, &info);
+  fillInCell(pParent, parentCell, 0, info.nKey, 0, 0, 0, &parentSize);
+  assert( parentSize<64 );
+  assert( sqlite3PagerIswriteable(pParent->pDbPage) );
+  insertCell(pParent, parentIdx, parentCell, parentSize, 0, 4);
+  put4byte(findOverflowCell(pParent,parentIdx), pPage->pgno);
+  put4byte(&pParent->aData[pParent->hdrOffset+8], pgnoNew);
+
+  /* If this is an auto-vacuum database, update the pointer map
+  ** with entries for the new page, and any pointer from the 
+  ** cell on the page to an overflow page.
+  */
+  if( ISAUTOVACUUM ){
+    rc = ptrmapPut(pBt, pgnoNew, PTRMAP_BTREE, pParent->pgno);
+    if( rc==SQLITE_OK ){
+      rc = ptrmapPutOvfl(pNew, 0);
+    }
+    if( rc!=SQLITE_OK ){
+      releasePage(pNew);
+      return rc;
+    }
+  }
+
+  /* Release the reference to the new page and balance the parent page,
+  ** in case the divider cell inserted caused it to become overfull.
+  */
+  releasePage(pNew);
+  return balance(pParent, 0);
+}
+#endif /* SQLITE_OMIT_QUICKBALANCE */
+
+/*
+** This routine redistributes Cells on pPage and up to NN*2 siblings
+** of pPage so that all pages have about the same amount of free space.
+** Usually NN siblings on either side of pPage is used in the balancing,
+** though more siblings might come from one side if pPage is the first
+** or last child of its parent.  If pPage has fewer than 2*NN siblings
+** (something which can only happen if pPage is the root page or a 
+** child of root) then all available siblings participate in the balancing.
+**
+** The number of siblings of pPage might be increased or decreased by one or
+** two in an effort to keep pages nearly full but not over full. The root page
+** is special and is allowed to be nearly empty. If pPage is 
+** the root page, then the depth of the tree might be increased
+** or decreased by one, as necessary, to keep the root page from being
+** overfull or completely empty.
+**
+** Note that when this routine is called, some of the Cells on pPage
+** might not actually be stored in pPage->aData[].  This can happen
+** if the page is overfull.  Part of the job of this routine is to
+** make sure all Cells for pPage once again fit in pPage->aData[].
+**
+** In the course of balancing the siblings of pPage, the parent of pPage
+** might become overfull or underfull.  If that happens, then this routine
+** is called recursively on the parent.
+**
+** If this routine fails for any reason, it might leave the database
+** in a corrupted state.  So if this routine fails, the database should
+** be rolled back.
+*/
+static int balance_nonroot(MemPage *pPage){
+  MemPage *pParent;            /* The parent of pPage */
+  BtShared *pBt;               /* The whole database */
+  int nCell = 0;               /* Number of cells in apCell[] */
+  int nMaxCells = 0;           /* Allocated size of apCell, szCell, aFrom. */
+  int nOld;                    /* Number of pages in apOld[] */
+  int nNew;                    /* Number of pages in apNew[] */
+  int nDiv;                    /* Number of cells in apDiv[] */
+  int i, j, k;                 /* Loop counters */
+  int idx;                     /* Index of pPage in pParent->aCell[] */
+  int nxDiv;                   /* Next divider slot in pParent->aCell[] */
+  int rc;                      /* The return code */
+  int leafCorrection;          /* 4 if pPage is a leaf.  0 if not */
+  int leafData;                /* True if pPage is a leaf of a LEAFDATA tree */
+  int usableSpace;             /* Bytes in pPage beyond the header */
+  int pageFlags;               /* Value of pPage->aData[0] */
+  int subtotal;                /* Subtotal of bytes in cells on one page */
+  int iSpace1 = 0;             /* First unused byte of aSpace1[] */
+  int iSpace2 = 0;             /* First unused byte of aSpace2[] */
+  int szScratch;               /* Size of scratch memory requested */
+  MemPage *apOld[NB];          /* pPage and up to two siblings */
+  Pgno pgnoOld[NB];            /* Page numbers for each page in apOld[] */
+  MemPage *apCopy[NB];         /* Private copies of apOld[] pages */
+  MemPage *apNew[NB+2];        /* pPage and up to NB siblings after balancing */
+  Pgno pgnoNew[NB+2];          /* Page numbers for each page in apNew[] */
+  u8 *apDiv[NB];               /* Divider cells in pParent */
+  int cntNew[NB+2];            /* Index in aCell[] of cell after i-th page */
+  int szNew[NB+2];             /* Combined size of cells place on i-th page */
+  u8 **apCell = 0;             /* All cells begin balanced */
+  u16 *szCell;                 /* Local size of all cells in apCell[] */
+  u8 *aCopy[NB];         /* Space for holding data of apCopy[] */
+  u8 *aSpace1;           /* Space for copies of dividers cells before balance */
+  u8 *aSpace2 = 0;       /* Space for overflow dividers cells after balance */
+  u8 *aFrom = 0;
+
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+
+  /* 
+  ** Find the parent page.
+  */
+  assert( pPage->isInit );
+  assert( sqlite3PagerIswriteable(pPage->pDbPage) || pPage->nOverflow==1 );
+  pBt = pPage->pBt;
+  pParent = pPage->pParent;
+  assert( pParent );
+  if( SQLITE_OK!=(rc = sqlite3PagerWrite(pParent->pDbPage)) ){
+    return rc;
+  }
+
+  TRACE(("BALANCE: begin page %d child of %d\n", pPage->pgno, pParent->pgno));
+
+#ifndef SQLITE_OMIT_QUICKBALANCE
+  /*
+  ** A special case:  If a new entry has just been inserted into a
+  ** table (that is, a btree with integer keys and all data at the leaves)
+  ** and the new entry is the right-most entry in the tree (it has the
+  ** largest key) then use the special balance_quick() routine for
+  ** balancing.  balance_quick() is much faster and results in a tighter
+  ** packing of data in the common case.
+  */
+  if( pPage->leaf &&
+      pPage->intKey &&
+      pPage->nOverflow==1 &&
+      pPage->aOvfl[0].idx==pPage->nCell &&
+      pPage->pParent->pgno!=1 &&
+      get4byte(&pParent->aData[pParent->hdrOffset+8])==pPage->pgno
+  ){
+    assert( pPage->intKey );
+    /*
+    ** TODO: Check the siblings to the left of pPage. It may be that
+    ** they are not full and no new page is required.
+    */
+    return balance_quick(pPage, pParent);
+  }
+#endif
+
+  if( SQLITE_OK!=(rc = sqlite3PagerWrite(pPage->pDbPage)) ){
+    return rc;
+  }
+
+  /*
+  ** Find the cell in the parent page whose left child points back
+  ** to pPage.  The "idx" variable is the index of that cell.  If pPage
+  ** is the rightmost child of pParent then set idx to pParent->nCell 
+  */
+  if( pParent->idxShift ){
+    Pgno pgno;
+    pgno = pPage->pgno;
+    assert( pgno==sqlite3PagerPagenumber(pPage->pDbPage) );
+    for(idx=0; idx<pParent->nCell; idx++){
+      if( get4byte(findCell(pParent, idx))==pgno ){
+        break;
+      }
+    }
+    assert( idx<pParent->nCell
+             || get4byte(&pParent->aData[pParent->hdrOffset+8])==pgno );
+  }else{
+    idx = pPage->idxParent;
+  }
+
+  /*
+  ** Initialize variables so that it will be safe to jump
+  ** directly to balance_cleanup at any moment.
+  */
+  nOld = nNew = 0;
+  sqlite3PagerRef(pParent->pDbPage);
+
+  /*
+  ** Find sibling pages to pPage and the cells in pParent that divide
+  ** the siblings.  An attempt is made to find NN siblings on either
+  ** side of pPage.  More siblings are taken from one side, however, if
+  ** pPage there are fewer than NN siblings on the other side.  If pParent
+  ** has NB or fewer children then all children of pParent are taken.
+  */
+  nxDiv = idx - NN;
+  if( nxDiv + NB > pParent->nCell ){
+    nxDiv = pParent->nCell - NB + 1;
+  }
+  if( nxDiv<0 ){
+    nxDiv = 0;
+  }
+  nDiv = 0;
+  for(i=0, k=nxDiv; i<NB; i++, k++){
+    if( k<pParent->nCell ){
+      apDiv[i] = findCell(pParent, k);
+      nDiv++;
+      assert( !pParent->leaf );
+      pgnoOld[i] = get4byte(apDiv[i]);
+    }else if( k==pParent->nCell ){
+      pgnoOld[i] = get4byte(&pParent->aData[pParent->hdrOffset+8]);
+    }else{
+      break;
+    }
+    rc = getAndInitPage(pBt, pgnoOld[i], &apOld[i], pParent);
+    if( rc ) goto balance_cleanup;
+    apOld[i]->idxParent = k;
+    apCopy[i] = 0;
+    assert( i==nOld );
+    nOld++;
+    nMaxCells += 1+apOld[i]->nCell+apOld[i]->nOverflow;
+  }
+
+  /* Make nMaxCells a multiple of 4 in order to preserve 8-byte
+  ** alignment */
+  nMaxCells = (nMaxCells + 3)&~3;
+
+  /*
+  ** Allocate space for memory structures
+  */
+  szScratch =
+       nMaxCells*sizeof(u8*)                       /* apCell */
+     + nMaxCells*sizeof(u16)                       /* szCell */
+     + (ROUND8(sizeof(MemPage))+pBt->pageSize)*NB  /* aCopy */
+     + pBt->pageSize                               /* aSpace1 */
+     + (ISAUTOVACUUM ? nMaxCells : 0);             /* aFrom */
+  apCell = sqlite3ScratchMalloc( szScratch ); 
+  if( apCell==0 ){
+    rc = SQLITE_NOMEM;
+    goto balance_cleanup;
+  }
+  szCell = (u16*)&apCell[nMaxCells];
+  aCopy[0] = (u8*)&szCell[nMaxCells];
+  assert( ((aCopy[0] - (u8*)apCell) & 7)==0 ); /* 8-byte alignment required */
+  for(i=1; i<NB; i++){
+    aCopy[i] = &aCopy[i-1][pBt->pageSize+ROUND8(sizeof(MemPage))];
+    assert( ((aCopy[i] - (u8*)apCell) & 7)==0 ); /* 8-byte alignment required */
+  }
+  aSpace1 = &aCopy[NB-1][pBt->pageSize+ROUND8(sizeof(MemPage))];
+  assert( ((aSpace1 - (u8*)apCell) & 7)==0 ); /* 8-byte alignment required */
+  if( ISAUTOVACUUM ){
+    aFrom = &aSpace1[pBt->pageSize];
+  }
+  aSpace2 = sqlite3PageMalloc(pBt->pageSize);
+  if( aSpace2==0 ){
+    rc = SQLITE_NOMEM;
+    goto balance_cleanup;
+  }
+  
+  /*
+  ** Make copies of the content of pPage and its siblings into aOld[].
+  ** The rest of this function will use data from the copies rather
+  ** that the original pages since the original pages will be in the
+  ** process of being overwritten.
+  */
+  for(i=0; i<nOld; i++){
+    MemPage *p = apCopy[i] = (MemPage*)aCopy[i];
+    memcpy(p, apOld[i], sizeof(MemPage));
+    p->aData = (void*)&p[1];
+    memcpy(p->aData, apOld[i]->aData, pBt->pageSize);
+  }
+
+  /*
+  ** Load pointers to all cells on sibling pages and the divider cells
+  ** into the local apCell[] array.  Make copies of the divider cells
+  ** into space obtained form aSpace1[] and remove the the divider Cells
+  ** from pParent.
+  **
+  ** If the siblings are on leaf pages, then the child pointers of the
+  ** divider cells are stripped from the cells before they are copied
+  ** into aSpace1[].  In this way, all cells in apCell[] are without
+  ** child pointers.  If siblings are not leaves, then all cell in
+  ** apCell[] include child pointers.  Either way, all cells in apCell[]
+  ** are alike.
+  **
+  ** leafCorrection:  4 if pPage is a leaf.  0 if pPage is not a leaf.
+  **       leafData:  1 if pPage holds key+data and pParent holds only keys.
+  */
+  nCell = 0;
+  leafCorrection = pPage->leaf*4;
+  leafData = pPage->hasData;
+  for(i=0; i<nOld; i++){
+    MemPage *pOld = apCopy[i];
+    int limit = pOld->nCell+pOld->nOverflow;
+    for(j=0; j<limit; j++){
+      assert( nCell<nMaxCells );
+      apCell[nCell] = findOverflowCell(pOld, j);
+      szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
+      if( ISAUTOVACUUM ){
+        int a;
+        aFrom[nCell] = i;
+        for(a=0; a<pOld->nOverflow; a++){
+          if( pOld->aOvfl[a].pCell==apCell[nCell] ){
+            aFrom[nCell] = 0xFF;
+            break;
+          }
+        }
+      }
+      nCell++;
+    }
+    if( i<nOld-1 ){
+      u16 sz = cellSizePtr(pParent, apDiv[i]);
+      if( leafData ){
+        /* With the LEAFDATA flag, pParent cells hold only INTKEYs that
+        ** are duplicates of keys on the child pages.  We need to remove
+        ** the divider cells from pParent, but the dividers cells are not
+        ** added to apCell[] because they are duplicates of child cells.
+        */
+        dropCell(pParent, nxDiv, sz);
+      }else{
+        u8 *pTemp;
+        assert( nCell<nMaxCells );
+        szCell[nCell] = sz;
+        pTemp = &aSpace1[iSpace1];
+        iSpace1 += sz;
+        assert( sz<=pBt->pageSize/4 );
+        assert( iSpace1<=pBt->pageSize );
+        memcpy(pTemp, apDiv[i], sz);
+        apCell[nCell] = pTemp+leafCorrection;
+        if( ISAUTOVACUUM ){
+          aFrom[nCell] = 0xFF;
+        }
+        dropCell(pParent, nxDiv, sz);
+        szCell[nCell] -= leafCorrection;
+        assert( get4byte(pTemp)==pgnoOld[i] );
+        if( !pOld->leaf ){
+          assert( leafCorrection==0 );
+          /* The right pointer of the child page pOld becomes the left
+          ** pointer of the divider cell */
+          memcpy(apCell[nCell], &pOld->aData[pOld->hdrOffset+8], 4);
+        }else{
+          assert( leafCorrection==4 );
+          if( szCell[nCell]<4 ){
+            /* Do not allow any cells smaller than 4 bytes. */
+            szCell[nCell] = 4;
+          }
+        }
+        nCell++;
+      }
+    }
+  }
+
+  /*
+  ** Figure out the number of pages needed to hold all nCell cells.
+  ** Store this number in "k".  Also compute szNew[] which is the total
+  ** size of all cells on the i-th page and cntNew[] which is the index
+  ** in apCell[] of the cell that divides page i from page i+1.  
+  ** cntNew[k] should equal nCell.
+  **
+  ** Values computed by this block:
+  **
+  **           k: The total number of sibling pages
+  **    szNew[i]: Spaced used on the i-th sibling page.
+  **   cntNew[i]: Index in apCell[] and szCell[] for the first cell to
+  **              the right of the i-th sibling page.
+  ** usableSpace: Number of bytes of space available on each sibling.
+  ** 
+  */
+  usableSpace = pBt->usableSize - 12 + leafCorrection;
+  for(subtotal=k=i=0; i<nCell; i++){
+    assert( i<nMaxCells );
+    subtotal += szCell[i] + 2;
+    if( subtotal > usableSpace ){
+      szNew[k] = subtotal - szCell[i];
+      cntNew[k] = i;
+      if( leafData ){ i--; }
+      subtotal = 0;
+      k++;
+    }
+  }
+  szNew[k] = subtotal;
+  cntNew[k] = nCell;
+  k++;
+
+  /*
+  ** The packing computed by the previous block is biased toward the siblings
+  ** on the left side.  The left siblings are always nearly full, while the
+  ** right-most sibling might be nearly empty.  This block of code attempts
+  ** to adjust the packing of siblings to get a better balance.
+  **
+  ** This adjustment is more than an optimization.  The packing above might
+  ** be so out of balance as to be illegal.  For example, the right-most
+  ** sibling might be completely empty.  This adjustment is not optional.
+  */
+  for(i=k-1; i>0; i--){
+    int szRight = szNew[i];  /* Size of sibling on the right */
+    int szLeft = szNew[i-1]; /* Size of sibling on the left */
+    int r;              /* Index of right-most cell in left sibling */
+    int d;              /* Index of first cell to the left of right sibling */
+
+    r = cntNew[i-1] - 1;
+    d = r + 1 - leafData;
+    assert( d<nMaxCells );
+    assert( r<nMaxCells );
+    while( szRight==0 || szRight+szCell[d]+2<=szLeft-(szCell[r]+2) ){
+      szRight += szCell[d] + 2;
+      szLeft -= szCell[r] + 2;
+      cntNew[i-1]--;
+      r = cntNew[i-1] - 1;
+      d = r + 1 - leafData;
+    }
+    szNew[i] = szRight;
+    szNew[i-1] = szLeft;
+  }
+
+  /* Either we found one or more cells (cntnew[0])>0) or we are the
+  ** a virtual root page.  A virtual root page is when the real root
+  ** page is page 1 and we are the only child of that page.
+  */
+  assert( cntNew[0]>0 || (pParent->pgno==1 && pParent->nCell==0) );
+
+  /*
+  ** Allocate k new pages.  Reuse old pages where possible.
+  */
+  assert( pPage->pgno>1 );
+  pageFlags = pPage->aData[0];
+  for(i=0; i<k; i++){
+    MemPage *pNew;
+    if( i<nOld ){
+      pNew = apNew[i] = apOld[i];
+      pgnoNew[i] = pgnoOld[i];
+      apOld[i] = 0;
+      rc = sqlite3PagerWrite(pNew->pDbPage);
+      nNew++;
+      if( rc ) goto balance_cleanup;
+    }else{
+      assert( i>0 );
+      rc = allocateBtreePage(pBt, &pNew, &pgnoNew[i], pgnoNew[i-1], 0);
+      if( rc ) goto balance_cleanup;
+      apNew[i] = pNew;
+      nNew++;
+    }
+  }
+
+  /* Free any old pages that were not reused as new pages.
+  */
+  while( i<nOld ){
+    rc = freePage(apOld[i]);
+    if( rc ) goto balance_cleanup;
+    releasePage(apOld[i]);
+    apOld[i] = 0;
+    i++;
+  }
+
+  /*
+  ** Put the new pages in accending order.  This helps to
+  ** keep entries in the disk file in order so that a scan
+  ** of the table is a linear scan through the file.  That
+  ** in turn helps the operating system to deliver pages
+  ** from the disk more rapidly.
+  **
+  ** An O(n^2) insertion sort algorithm is used, but since
+  ** n is never more than NB (a small constant), that should
+  ** not be a problem.
+  **
+  ** When NB==3, this one optimization makes the database
+  ** about 25% faster for large insertions and deletions.
+  */
+  for(i=0; i<k-1; i++){
+    int minV = pgnoNew[i];
+    int minI = i;
+    for(j=i+1; j<k; j++){
+      if( pgnoNew[j]<(unsigned)minV ){
+        minI = j;
+        minV = pgnoNew[j];
+      }
+    }
+    if( minI>i ){
+      int t;
+      MemPage *pT;
+      t = pgnoNew[i];
+      pT = apNew[i];
+      pgnoNew[i] = pgnoNew[minI];
+      apNew[i] = apNew[minI];
+      pgnoNew[minI] = t;
+      apNew[minI] = pT;
+    }
+  }
+  TRACE(("BALANCE: old: %d %d %d  new: %d(%d) %d(%d) %d(%d) %d(%d) %d(%d)\n",
+    pgnoOld[0], 
+    nOld>=2 ? pgnoOld[1] : 0,
+    nOld>=3 ? pgnoOld[2] : 0,
+    pgnoNew[0], szNew[0],
+    nNew>=2 ? pgnoNew[1] : 0, nNew>=2 ? szNew[1] : 0,
+    nNew>=3 ? pgnoNew[2] : 0, nNew>=3 ? szNew[2] : 0,
+    nNew>=4 ? pgnoNew[3] : 0, nNew>=4 ? szNew[3] : 0,
+    nNew>=5 ? pgnoNew[4] : 0, nNew>=5 ? szNew[4] : 0));
+
+  /*
+  ** Evenly distribute the data in apCell[] across the new pages.
+  ** Insert divider cells into pParent as necessary.
+  */
+  j = 0;
+  for(i=0; i<nNew; i++){
+    /* Assemble the new sibling page. */
+    MemPage *pNew = apNew[i];
+    assert( j<nMaxCells );
+    assert( pNew->pgno==pgnoNew[i] );
+    zeroPage(pNew, pageFlags);
+    assemblePage(pNew, cntNew[i]-j, &apCell[j], &szCell[j]);
+    assert( pNew->nCell>0 || (nNew==1 && cntNew[0]==0) );
+    assert( pNew->nOverflow==0 );
+
+    /* If this is an auto-vacuum database, update the pointer map entries
+    ** that point to the siblings that were rearranged. These can be: left
+    ** children of cells, the right-child of the page, or overflow pages
+    ** pointed to by cells.
+    */
+    if( ISAUTOVACUUM ){
+      for(k=j; k<cntNew[i]; k++){
+        assert( k<nMaxCells );
+        if( aFrom[k]==0xFF || apCopy[aFrom[k]]->pgno!=pNew->pgno ){
+          rc = ptrmapPutOvfl(pNew, k-j);
+          if( rc==SQLITE_OK && leafCorrection==0 ){
+            rc = ptrmapPut(pBt, get4byte(apCell[k]), PTRMAP_BTREE, pNew->pgno);
+          }
+          if( rc!=SQLITE_OK ){
+            goto balance_cleanup;
+          }
+        }
+      }
+    }
+
+    j = cntNew[i];
+
+    /* If the sibling page assembled above was not the right-most sibling,
+    ** insert a divider cell into the parent page.
+    */
+    if( i<nNew-1 && j<nCell ){
+      u8 *pCell;
+      u8 *pTemp;
+      int sz;
+
+      assert( j<nMaxCells );
+      pCell = apCell[j];
+      sz = szCell[j] + leafCorrection;
+      pTemp = &aSpace2[iSpace2];
+      if( !pNew->leaf ){
+        memcpy(&pNew->aData[8], pCell, 4);
+        if( ISAUTOVACUUM 
+         && (aFrom[j]==0xFF || apCopy[aFrom[j]]->pgno!=pNew->pgno)
+        ){
+          rc = ptrmapPut(pBt, get4byte(pCell), PTRMAP_BTREE, pNew->pgno);
+          if( rc!=SQLITE_OK ){
+            goto balance_cleanup;
+          }
+        }
+      }else if( leafData ){
+        /* If the tree is a leaf-data tree, and the siblings are leaves, 
+        ** then there is no divider cell in apCell[]. Instead, the divider 
+        ** cell consists of the integer key for the right-most cell of 
+        ** the sibling-page assembled above only.
+        */
+        CellInfo info;
+        j--;
+        sqlite3BtreeParseCellPtr(pNew, apCell[j], &info);
+        pCell = pTemp;
+        fillInCell(pParent, pCell, 0, info.nKey, 0, 0, 0, &sz);
+        pTemp = 0;
+      }else{
+        pCell -= 4;
+        /* Obscure case for non-leaf-data trees: If the cell at pCell was
+        ** previously stored on a leaf node, and its reported size was 4
+        ** bytes, then it may actually be smaller than this 
+        ** (see sqlite3BtreeParseCellPtr(), 4 bytes is the minimum size of
+        ** any cell). But it is important to pass the correct size to 
+        ** insertCell(), so reparse the cell now.
+        **
+        ** Note that this can never happen in an SQLite data file, as all
+        ** cells are at least 4 bytes. It only happens in b-trees used
+        ** to evaluate "IN (SELECT ...)" and similar clauses.
+        */
+        if( szCell[j]==4 ){
+          assert(leafCorrection==4);
+          sz = cellSizePtr(pParent, pCell);
+        }
+      }
+      iSpace2 += sz;
+      assert( sz<=pBt->pageSize/4 );
+      assert( iSpace2<=pBt->pageSize );
+      rc = insertCell(pParent, nxDiv, pCell, sz, pTemp, 4);
+      if( rc!=SQLITE_OK ) goto balance_cleanup;
+      put4byte(findOverflowCell(pParent,nxDiv), pNew->pgno);
+
+      /* If this is an auto-vacuum database, and not a leaf-data tree,
+      ** then update the pointer map with an entry for the overflow page
+      ** that the cell just inserted points to (if any).
+      */
+      if( ISAUTOVACUUM && !leafData ){
+        rc = ptrmapPutOvfl(pParent, nxDiv);
+        if( rc!=SQLITE_OK ){
+          goto balance_cleanup;
+        }
+      }
+      j++;
+      nxDiv++;
+    }
+
+    /* Set the pointer-map entry for the new sibling page. */
+    if( ISAUTOVACUUM ){
+      rc = ptrmapPut(pBt, pNew->pgno, PTRMAP_BTREE, pParent->pgno);
+      if( rc!=SQLITE_OK ){
+        goto balance_cleanup;
+      }
+    }
+  }
+  assert( j==nCell );
+  assert( nOld>0 );
+  assert( nNew>0 );
+  if( (pageFlags & PTF_LEAF)==0 ){
+    u8 *zChild = &apCopy[nOld-1]->aData[8];
+    memcpy(&apNew[nNew-1]->aData[8], zChild, 4);
+    if( ISAUTOVACUUM ){
+      rc = ptrmapPut(pBt, get4byte(zChild), PTRMAP_BTREE, apNew[nNew-1]->pgno);
+      if( rc!=SQLITE_OK ){
+        goto balance_cleanup;
+      }
+    }
+  }
+  if( nxDiv==pParent->nCell+pParent->nOverflow ){
+    /* Right-most sibling is the right-most child of pParent */
+    put4byte(&pParent->aData[pParent->hdrOffset+8], pgnoNew[nNew-1]);
+  }else{
+    /* Right-most sibling is the left child of the first entry in pParent
+    ** past the right-most divider entry */
+    put4byte(findOverflowCell(pParent, nxDiv), pgnoNew[nNew-1]);
+  }
+
+  /*
+  ** Reparent children of all cells.
+  */
+  for(i=0; i<nNew; i++){
+    rc = reparentChildPages(apNew[i], 0);
+    if( rc!=SQLITE_OK ) goto balance_cleanup;
+  }
+  rc = reparentChildPages(pParent, 0);
+  if( rc!=SQLITE_OK ) goto balance_cleanup;
+
+  /*
+  ** Balance the parent page.  Note that the current page (pPage) might
+  ** have been added to the freelist so it might no longer be initialized.
+  ** But the parent page will always be initialized.
+  */
+  assert( pParent->isInit );
+  sqlite3ScratchFree(apCell);
+  apCell = 0;
+  rc = balance(pParent, 0);
+  
+  /*
+  ** Cleanup before returning.
+  */
+balance_cleanup:
+  sqlite3PageFree(aSpace2);
+  sqlite3ScratchFree(apCell);
+  for(i=0; i<nOld; i++){
+    releasePage(apOld[i]);
+  }
+  for(i=0; i<nNew; i++){
+    releasePage(apNew[i]);
+  }
+  releasePage(pParent);
+  TRACE(("BALANCE: finished with %d: old=%d new=%d cells=%d\n",
+          pPage->pgno, nOld, nNew, nCell));
+  return rc;
+}
+
+/*
+** This routine is called for the root page of a btree when the root
+** page contains no cells.  This is an opportunity to make the tree
+** shallower by one level.
+*/
+static int balance_shallower(MemPage *pPage){
+  MemPage *pChild;             /* The only child page of pPage */
+  Pgno pgnoChild;              /* Page number for pChild */
+  int rc = SQLITE_OK;          /* Return code from subprocedures */
+  BtShared *pBt;                  /* The main BTree structure */
+  int mxCellPerPage;           /* Maximum number of cells per page */
+  u8 **apCell;                 /* All cells from pages being balanced */
+  u16 *szCell;                 /* Local size of all cells */
+
+  assert( pPage->pParent==0 );
+  assert( pPage->nCell==0 );
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  pBt = pPage->pBt;
+  mxCellPerPage = MX_CELL(pBt);
+  apCell = sqlite3Malloc( mxCellPerPage*(sizeof(u8*)+sizeof(u16)) );
+  if( apCell==0 ) return SQLITE_NOMEM;
+  szCell = (u16*)&apCell[mxCellPerPage];
+  if( pPage->leaf ){
+    /* The table is completely empty */
+    TRACE(("BALANCE: empty table %d\n", pPage->pgno));
+  }else{
+    /* The root page is empty but has one child.  Transfer the
+    ** information from that one child into the root page if it 
+    ** will fit.  This reduces the depth of the tree by one.
+    **
+    ** If the root page is page 1, it has less space available than
+    ** its child (due to the 100 byte header that occurs at the beginning
+    ** of the database fle), so it might not be able to hold all of the 
+    ** information currently contained in the child.  If this is the 
+    ** case, then do not do the transfer.  Leave page 1 empty except
+    ** for the right-pointer to the child page.  The child page becomes
+    ** the virtual root of the tree.
+    */
+    pgnoChild = get4byte(&pPage->aData[pPage->hdrOffset+8]);
+    assert( pgnoChild>0 );
+    assert( pgnoChild<=pagerPagecount(pPage->pBt->pPager) );
+    rc = sqlite3BtreeGetPage(pPage->pBt, pgnoChild, &pChild, 0);
+    if( rc ) goto end_shallow_balance;
+    if( pPage->pgno==1 ){
+      rc = sqlite3BtreeInitPage(pChild, pPage);
+      if( rc ) goto end_shallow_balance;
+      assert( pChild->nOverflow==0 );
+      if( pChild->nFree>=100 ){
+        /* The child information will fit on the root page, so do the
+        ** copy */
+        int i;
+        zeroPage(pPage, pChild->aData[0]);
+        for(i=0; i<pChild->nCell; i++){
+          apCell[i] = findCell(pChild,i);
+          szCell[i] = cellSizePtr(pChild, apCell[i]);
+        }
+        assemblePage(pPage, pChild->nCell, apCell, szCell);
+        /* Copy the right-pointer of the child to the parent. */
+        put4byte(&pPage->aData[pPage->hdrOffset+8], 
+            get4byte(&pChild->aData[pChild->hdrOffset+8]));
+        freePage(pChild);
+        TRACE(("BALANCE: child %d transfer to page 1\n", pChild->pgno));
+      }else{
+        /* The child has more information that will fit on the root.
+        ** The tree is already balanced.  Do nothing. */
+        TRACE(("BALANCE: child %d will not fit on page 1\n", pChild->pgno));
+      }
+    }else{
+      memcpy(pPage->aData, pChild->aData, pPage->pBt->usableSize);
+      pPage->isInit = 0;
+      pPage->pParent = 0;
+      rc = sqlite3BtreeInitPage(pPage, 0);
+      assert( rc==SQLITE_OK );
+      freePage(pChild);
+      TRACE(("BALANCE: transfer child %d into root %d\n",
+              pChild->pgno, pPage->pgno));
+    }
+    rc = reparentChildPages(pPage, 1);
+    assert( pPage->nOverflow==0 );
+    if( ISAUTOVACUUM ){
+      int i;
+      for(i=0; i<pPage->nCell; i++){ 
+        rc = ptrmapPutOvfl(pPage, i);
+        if( rc!=SQLITE_OK ){
+          goto end_shallow_balance;
+        }
+      }
+    }
+    releasePage(pChild);
+  }
+end_shallow_balance:
+  sqlite3_free(apCell);
+  return rc;
+}
+
+
+/*
+** The root page is overfull
+**
+** When this happens, Create a new child page and copy the
+** contents of the root into the child.  Then make the root
+** page an empty page with rightChild pointing to the new
+** child.   Finally, call balance_internal() on the new child
+** to cause it to split.
+*/
+static int balance_deeper(MemPage *pPage){
+  int rc;             /* Return value from subprocedures */
+  MemPage *pChild;    /* Pointer to a new child page */
+  Pgno pgnoChild;     /* Page number of the new child page */
+  BtShared *pBt;         /* The BTree */
+  int usableSize;     /* Total usable size of a page */
+  u8 *data;           /* Content of the parent page */
+  u8 *cdata;          /* Content of the child page */
+  int hdr;            /* Offset to page header in parent */
+  int brk;            /* Offset to content of first cell in parent */
+
+  assert( pPage->pParent==0 );
+  assert( pPage->nOverflow>0 );
+  pBt = pPage->pBt;
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  rc = allocateBtreePage(pBt, &pChild, &pgnoChild, pPage->pgno, 0);
+  if( rc ) return rc;
+  assert( sqlite3PagerIswriteable(pChild->pDbPage) );
+  usableSize = pBt->usableSize;
+  data = pPage->aData;
+  hdr = pPage->hdrOffset;
+  brk = get2byte(&data[hdr+5]);
+  cdata = pChild->aData;
+  memcpy(cdata, &data[hdr], pPage->cellOffset+2*pPage->nCell-hdr);
+  memcpy(&cdata[brk], &data[brk], usableSize-brk);
+  if( pChild->isInit ) return SQLITE_CORRUPT;
+  rc = sqlite3BtreeInitPage(pChild, pPage);
+  if( rc ) goto balancedeeper_out;
+  memcpy(pChild->aOvfl, pPage->aOvfl, pPage->nOverflow*sizeof(pPage->aOvfl[0]));
+  pChild->nOverflow = pPage->nOverflow;
+  if( pChild->nOverflow ){
+    pChild->nFree = 0;
+  }
+  assert( pChild->nCell==pPage->nCell );
+  zeroPage(pPage, pChild->aData[0] & ~PTF_LEAF);
+  put4byte(&pPage->aData[pPage->hdrOffset+8], pgnoChild);
+  TRACE(("BALANCE: copy root %d into %d\n", pPage->pgno, pChild->pgno));
+  if( ISAUTOVACUUM ){
+    int i;
+    rc = ptrmapPut(pBt, pChild->pgno, PTRMAP_BTREE, pPage->pgno);
+    if( rc ) goto balancedeeper_out;
+    for(i=0; i<pChild->nCell; i++){
+      rc = ptrmapPutOvfl(pChild, i);
+      if( rc!=SQLITE_OK ){
+        goto balancedeeper_out;
+      }
+    }
+    rc = reparentChildPages(pChild, 1);
+  }
+  if( rc==SQLITE_OK ){
+    rc = balance_nonroot(pChild);
+  }
+
+balancedeeper_out:
+  releasePage(pChild);
+  return rc;
+}
+
+/*
+** Decide if the page pPage needs to be balanced.  If balancing is
+** required, call the appropriate balancing routine.
+*/
+static int balance(MemPage *pPage, int insert){
+  int rc = SQLITE_OK;
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  if( pPage->pParent==0 ){
+    rc = sqlite3PagerWrite(pPage->pDbPage);
+    if( rc==SQLITE_OK && pPage->nOverflow>0 ){
+      rc = balance_deeper(pPage);
+    }
+    if( rc==SQLITE_OK && pPage->nCell==0 ){
+      rc = balance_shallower(pPage);
+    }
+  }else{
+    if( pPage->nOverflow>0 || 
+        (!insert && pPage->nFree>pPage->pBt->usableSize*2/3) ){
+      rc = balance_nonroot(pPage);
+    }
+  }
+  return rc;
+}
+
+/*
+** This routine checks all cursors that point to table pgnoRoot.
+** If any of those cursors were opened with wrFlag==0 in a different
+** database connection (a database connection that shares the pager
+** cache with the current connection) and that other connection 
+** is not in the ReadUncommmitted state, then this routine returns 
+** SQLITE_LOCKED.
+**
+** As well as cursors with wrFlag==0, cursors with wrFlag==1 and 
+** isIncrblobHandle==1 are also considered 'read' cursors. Incremental 
+** blob cursors are used for both reading and writing.
+**
+** When pgnoRoot is the root page of an intkey table, this function is also
+** responsible for invalidating incremental blob cursors when the table row
+** on which they are opened is deleted or modified. Cursors are invalidated
+** according to the following rules:
+**
+**   1) When BtreeClearTable() is called to completely delete the contents
+**      of a B-Tree table, pExclude is set to zero and parameter iRow is 
+**      set to non-zero. In this case all incremental blob cursors open
+**      on the table rooted at pgnoRoot are invalidated.
+**
+**   2) When BtreeInsert(), BtreeDelete() or BtreePutData() is called to 
+**      modify a table row via an SQL statement, pExclude is set to the 
+**      write cursor used to do the modification and parameter iRow is set
+**      to the integer row id of the B-Tree entry being modified. Unless
+**      pExclude is itself an incremental blob cursor, then all incremental
+**      blob cursors open on row iRow of the B-Tree are invalidated.
+**
+**   3) If both pExclude and iRow are set to zero, no incremental blob 
+**      cursors are invalidated.
+*/
+static int checkReadLocks(
+  Btree *pBtree, 
+  Pgno pgnoRoot, 
+  BtCursor *pExclude,
+  i64 iRow
+){
+  BtCursor *p;
+  BtShared *pBt = pBtree->pBt;
+  sqlite3 *db = pBtree->db;
+  assert( sqlite3BtreeHoldsMutex(pBtree) );
+  for(p=pBt->pCursor; p; p=p->pNext){
+    if( p==pExclude ) continue;
+    if( p->pgnoRoot!=pgnoRoot ) continue;
+#ifndef SQLITE_OMIT_INCRBLOB
+    if( p->isIncrblobHandle && ( 
+         (!pExclude && iRow)
+      || (pExclude && !pExclude->isIncrblobHandle && p->info.nKey==iRow)
+    )){
+      p->eState = CURSOR_INVALID;
+    }
+#endif
+    if( p->eState!=CURSOR_VALID ) continue;
+    if( p->wrFlag==0 
+#ifndef SQLITE_OMIT_INCRBLOB
+     || p->isIncrblobHandle
+#endif
+    ){
+      sqlite3 *dbOther = p->pBtree->db;
+      if( dbOther==0 ||
+         (dbOther!=db && (dbOther->flags & SQLITE_ReadUncommitted)==0) ){
+        return SQLITE_LOCKED;
+      }
+    }
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Insert a new record into the BTree.  The key is given by (pKey,nKey)
+** and the data is given by (pData,nData).  The cursor is used only to
+** define what table the record should be inserted into.  The cursor
+** is left pointing at a random location.
+**
+** For an INTKEY table, only the nKey value of the key is used.  pKey is
+** ignored.  For a ZERODATA table, the pData and nData are both ignored.
+*/
+int sqlite3BtreeInsert(
+  BtCursor *pCur,                /* Insert data into the table of this cursor */
+  const void *pKey, i64 nKey,    /* The key of the new record */
+  const void *pData, int nData,  /* The data of the new record */
+  int nZero,                     /* Number of extra 0 bytes to append to data */
+  int appendBias                 /* True if this is likely an append */
+){
+  int rc;
+  int loc;
+  int szNew;
+  MemPage *pPage;
+  Btree *p = pCur->pBtree;
+  BtShared *pBt = p->pBt;
+  unsigned char *oldCell;
+  unsigned char *newCell = 0;
+
+  assert( cursorHoldsMutex(pCur) );
+  if( pBt->inTransaction!=TRANS_WRITE ){
+    /* Must start a transaction before doing an insert */
+    rc = pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
+    return rc;
+  }
+  assert( !pBt->readOnly );
+  if( !pCur->wrFlag ){
+    return SQLITE_PERM;   /* Cursor not open for writing */
+  }
+  if( checkReadLocks(pCur->pBtree, pCur->pgnoRoot, pCur, nKey) ){
+    return SQLITE_LOCKED; /* The table pCur points to has a read lock */
+  }
+  if( pCur->eState==CURSOR_FAULT ){
+    return pCur->skip;
+  }
+
+  /* Save the positions of any other cursors open on this table */
+  clearCursorPosition(pCur);
+  if( 
+    SQLITE_OK!=(rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur)) ||
+    SQLITE_OK!=(rc = sqlite3BtreeMoveto(pCur, pKey, 0, nKey, appendBias, &loc))
+  ){
+    return rc;
+  }
+
+  pPage = pCur->pPage;
+  assert( pPage->intKey || nKey>=0 );
+  assert( pPage->leaf || !pPage->intKey );
+  TRACE(("INSERT: table=%d nkey=%lld ndata=%d page=%d %s\n",
+          pCur->pgnoRoot, nKey, nData, pPage->pgno,
+          loc==0 ? "overwrite" : "new entry"));
+  assert( pPage->isInit );
+  allocateTempSpace(pBt);
+  newCell = pBt->pTmpSpace;
+  if( newCell==0 ) return SQLITE_NOMEM;
+  rc = fillInCell(pPage, newCell, pKey, nKey, pData, nData, nZero, &szNew);
+  if( rc ) goto end_insert;
+  assert( szNew==cellSizePtr(pPage, newCell) );
+  assert( szNew<=MX_CELL_SIZE(pBt) );
+  if( loc==0 && CURSOR_VALID==pCur->eState ){
+    u16 szOld;
+    assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
+    rc = sqlite3PagerWrite(pPage->pDbPage);
+    if( rc ){
+      goto end_insert;
+    }
+    oldCell = findCell(pPage, pCur->idx);
+    if( !pPage->leaf ){
+      memcpy(newCell, oldCell, 4);
+    }
+    szOld = cellSizePtr(pPage, oldCell);
+    rc = clearCell(pPage, oldCell);
+    if( rc ) goto end_insert;
+    dropCell(pPage, pCur->idx, szOld);
+  }else if( loc<0 && pPage->nCell>0 ){
+    assert( pPage->leaf );
+    pCur->idx++;
+    pCur->info.nSize = 0;
+    pCur->validNKey = 0;
+  }else{
+    assert( pPage->leaf );
+  }
+  rc = insertCell(pPage, pCur->idx, newCell, szNew, 0, 0);
+  if( rc!=SQLITE_OK ) goto end_insert;
+  rc = balance(pPage, 1);
+  if( rc==SQLITE_OK ){
+    moveToRoot(pCur);
+  }
+end_insert:
+  return rc;
+}
+
+/*
+** Delete the entry that the cursor is pointing to.  The cursor
+** is left pointing at a random location.
+*/
+int sqlite3BtreeDelete(BtCursor *pCur){
+  MemPage *pPage = pCur->pPage;
+  unsigned char *pCell;
+  int rc;
+  Pgno pgnoChild = 0;
+  Btree *p = pCur->pBtree;
+  BtShared *pBt = p->pBt;
+
+  assert( cursorHoldsMutex(pCur) );
+  assert( pPage->isInit );
+  if( pBt->inTransaction!=TRANS_WRITE ){
+    /* Must start a transaction before doing a delete */
+    rc = pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
+    return rc;
+  }
+  assert( !pBt->readOnly );
+  if( pCur->eState==CURSOR_FAULT ){
+    return pCur->skip;
+  }
+  if( pCur->idx >= pPage->nCell ){
+    return SQLITE_ERROR;  /* The cursor is not pointing to anything */
+  }
+  if( !pCur->wrFlag ){
+    return SQLITE_PERM;   /* Did not open this cursor for writing */
+  }
+  if( checkReadLocks(pCur->pBtree, pCur->pgnoRoot, pCur, pCur->info.nKey) ){
+    return SQLITE_LOCKED; /* The table pCur points to has a read lock */
+  }
+
+  /* Restore the current cursor position (a no-op if the cursor is not in 
+  ** CURSOR_REQUIRESEEK state) and save the positions of any other cursors 
+  ** open on the same table. Then call sqlite3PagerWrite() on the page
+  ** that the entry will be deleted from.
+  */
+  if( 
+    (rc = restoreCursorPosition(pCur))!=0 ||
+    (rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur))!=0 ||
+    (rc = sqlite3PagerWrite(pPage->pDbPage))!=0
+  ){
+    return rc;
+  }
+
+  /* Locate the cell within its page and leave pCell pointing to the
+  ** data. The clearCell() call frees any overflow pages associated with the
+  ** cell. The cell itself is still intact.
+  */
+  pCell = findCell(pPage, pCur->idx);
+  if( !pPage->leaf ){
+    pgnoChild = get4byte(pCell);
+  }
+  rc = clearCell(pPage, pCell);
+  if( rc ){
+    return rc;
+  }
+
+  if( !pPage->leaf ){
+    /*
+    ** The entry we are about to delete is not a leaf so if we do not
+    ** do something we will leave a hole on an internal page.
+    ** We have to fill the hole by moving in a cell from a leaf.  The
+    ** next Cell after the one to be deleted is guaranteed to exist and
+    ** to be a leaf so we can use it.
+    */
+    BtCursor leafCur;
+    unsigned char *pNext;
+    int notUsed;
+    unsigned char *tempCell = 0;
+    assert( !pPage->intKey );
+    sqlite3BtreeGetTempCursor(pCur, &leafCur);
+    rc = sqlite3BtreeNext(&leafCur, &notUsed);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3PagerWrite(leafCur.pPage->pDbPage);
+    }
+    if( rc==SQLITE_OK ){
+      u16 szNext;
+      TRACE(("DELETE: table=%d delete internal from %d replace from leaf %d\n",
+         pCur->pgnoRoot, pPage->pgno, leafCur.pPage->pgno));
+      dropCell(pPage, pCur->idx, cellSizePtr(pPage, pCell));
+      pNext = findCell(leafCur.pPage, leafCur.idx);
+      szNext = cellSizePtr(leafCur.pPage, pNext);
+      assert( MX_CELL_SIZE(pBt)>=szNext+4 );
+      allocateTempSpace(pBt);
+      tempCell = pBt->pTmpSpace;
+      if( tempCell==0 ){
+        rc = SQLITE_NOMEM;
+      }
+      if( rc==SQLITE_OK ){
+        rc = insertCell(pPage, pCur->idx, pNext-4, szNext+4, tempCell, 0);
+      }
+      if( rc==SQLITE_OK ){
+        put4byte(findOverflowCell(pPage, pCur->idx), pgnoChild);
+        rc = balance(pPage, 0);
+      }
+      if( rc==SQLITE_OK ){
+        dropCell(leafCur.pPage, leafCur.idx, szNext);
+        rc = balance(leafCur.pPage, 0);
+      }
+    }
+    sqlite3BtreeReleaseTempCursor(&leafCur);
+  }else{
+    TRACE(("DELETE: table=%d delete from leaf %d\n",
+       pCur->pgnoRoot, pPage->pgno));
+    dropCell(pPage, pCur->idx, cellSizePtr(pPage, pCell));
+    rc = balance(pPage, 0);
+  }
+  if( rc==SQLITE_OK ){
+    moveToRoot(pCur);
+  }
+  return rc;
+}
+
+/*
+** Create a new BTree table.  Write into *piTable the page
+** number for the root page of the new table.
+**
+** The type of type is determined by the flags parameter.  Only the
+** following values of flags are currently in use.  Other values for
+** flags might not work:
+**
+**     BTREE_INTKEY|BTREE_LEAFDATA     Used for SQL tables with rowid keys
+**     BTREE_ZERODATA                  Used for SQL indices
+*/
+static int btreeCreateTable(Btree *p, int *piTable, int flags){
+  BtShared *pBt = p->pBt;
+  MemPage *pRoot;
+  Pgno pgnoRoot;
+  int rc;
+
+  assert( sqlite3BtreeHoldsMutex(p) );
+  if( pBt->inTransaction!=TRANS_WRITE ){
+    /* Must start a transaction first */
+    rc = pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
+    return rc;
+  }
+  assert( !pBt->readOnly );
+
+#ifdef SQLITE_OMIT_AUTOVACUUM
+  rc = allocateBtreePage(pBt, &pRoot, &pgnoRoot, 1, 0);
+  if( rc ){
+    return rc;
+  }
+#else
+  if( pBt->autoVacuum ){
+    Pgno pgnoMove;      /* Move a page here to make room for the root-page */
+    MemPage *pPageMove; /* The page to move to. */
+
+    /* Creating a new table may probably require moving an existing database
+    ** to make room for the new tables root page. In case this page turns
+    ** out to be an overflow page, delete all overflow page-map caches
+    ** held by open cursors.
+    */
+    invalidateAllOverflowCache(pBt);
+
+    /* Read the value of meta[3] from the database to determine where the
+    ** root page of the new table should go. meta[3] is the largest root-page
+    ** created so far, so the new root-page is (meta[3]+1).
+    */
+    rc = sqlite3BtreeGetMeta(p, 4, &pgnoRoot);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    pgnoRoot++;
+
+    /* The new root-page may not be allocated on a pointer-map page, or the
+    ** PENDING_BYTE page.
+    */
+    while( pgnoRoot==PTRMAP_PAGENO(pBt, pgnoRoot) ||
+        pgnoRoot==PENDING_BYTE_PAGE(pBt) ){
+      pgnoRoot++;
+    }
+    assert( pgnoRoot>=3 );
+
+    /* Allocate a page. The page that currently resides at pgnoRoot will
+    ** be moved to the allocated page (unless the allocated page happens
+    ** to reside at pgnoRoot).
+    */
+    rc = allocateBtreePage(pBt, &pPageMove, &pgnoMove, pgnoRoot, 1);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+
+    if( pgnoMove!=pgnoRoot ){
+      /* pgnoRoot is the page that will be used for the root-page of
+      ** the new table (assuming an error did not occur). But we were
+      ** allocated pgnoMove. If required (i.e. if it was not allocated
+      ** by extending the file), the current page at position pgnoMove
+      ** is already journaled.
+      */
+      u8 eType;
+      Pgno iPtrPage;
+
+      releasePage(pPageMove);
+
+      /* Move the page currently at pgnoRoot to pgnoMove. */
+      rc = sqlite3BtreeGetPage(pBt, pgnoRoot, &pRoot, 0);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      rc = ptrmapGet(pBt, pgnoRoot, &eType, &iPtrPage);
+      if( rc!=SQLITE_OK || eType==PTRMAP_ROOTPAGE || eType==PTRMAP_FREEPAGE ){
+        releasePage(pRoot);
+        return rc;
+      }
+      assert( eType!=PTRMAP_ROOTPAGE );
+      assert( eType!=PTRMAP_FREEPAGE );
+      rc = sqlite3PagerWrite(pRoot->pDbPage);
+      if( rc!=SQLITE_OK ){
+        releasePage(pRoot);
+        return rc;
+      }
+      rc = relocatePage(pBt, pRoot, eType, iPtrPage, pgnoMove, 0);
+      releasePage(pRoot);
+
+      /* Obtain the page at pgnoRoot */
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      rc = sqlite3BtreeGetPage(pBt, pgnoRoot, &pRoot, 0);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      rc = sqlite3PagerWrite(pRoot->pDbPage);
+      if( rc!=SQLITE_OK ){
+        releasePage(pRoot);
+        return rc;
+      }
+    }else{
+      pRoot = pPageMove;
+    } 
+
+    /* Update the pointer-map and meta-data with the new root-page number. */
+    rc = ptrmapPut(pBt, pgnoRoot, PTRMAP_ROOTPAGE, 0);
+    if( rc ){
+      releasePage(pRoot);
+      return rc;
+    }
+    rc = sqlite3BtreeUpdateMeta(p, 4, pgnoRoot);
+    if( rc ){
+      releasePage(pRoot);
+      return rc;
+    }
+
+  }else{
+    rc = allocateBtreePage(pBt, &pRoot, &pgnoRoot, 1, 0);
+    if( rc ) return rc;
+  }
+#endif
+  assert( sqlite3PagerIswriteable(pRoot->pDbPage) );
+  zeroPage(pRoot, flags | PTF_LEAF);
+  sqlite3PagerUnref(pRoot->pDbPage);
+  *piTable = (int)pgnoRoot;
+  return SQLITE_OK;
+}
+int sqlite3BtreeCreateTable(Btree *p, int *piTable, int flags){
+  int rc;
+  sqlite3BtreeEnter(p);
+  p->pBt->db = p->db;
+  rc = btreeCreateTable(p, piTable, flags);
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+/*
+** Erase the given database page and all its children.  Return
+** the page to the freelist.
+*/
+static int clearDatabasePage(
+  BtShared *pBt,           /* The BTree that contains the table */
+  Pgno pgno,            /* Page number to clear */
+  MemPage *pParent,     /* Parent page.  NULL for the root */
+  int freePageFlag      /* Deallocate page if true */
+){
+  MemPage *pPage = 0;
+  int rc;
+  unsigned char *pCell;
+  int i;
+
+  assert( sqlite3_mutex_held(pBt->mutex) );
+  if( pgno>pagerPagecount(pBt->pPager) ){
+    return SQLITE_CORRUPT_BKPT;
+  }
+
+  rc = getAndInitPage(pBt, pgno, &pPage, pParent);
+  if( rc ) goto cleardatabasepage_out;
+  for(i=0; i<pPage->nCell; i++){
+    pCell = findCell(pPage, i);
+    if( !pPage->leaf ){
+      rc = clearDatabasePage(pBt, get4byte(pCell), pPage->pParent, 1);
+      if( rc ) goto cleardatabasepage_out;
+    }
+    rc = clearCell(pPage, pCell);
+    if( rc ) goto cleardatabasepage_out;
+  }
+  if( !pPage->leaf ){
+    rc = clearDatabasePage(pBt, get4byte(&pPage->aData[8]), pPage->pParent, 1);
+    if( rc ) goto cleardatabasepage_out;
+  }
+  if( freePageFlag ){
+    rc = freePage(pPage);
+  }else if( (rc = sqlite3PagerWrite(pPage->pDbPage))==0 ){
+    zeroPage(pPage, pPage->aData[0] | PTF_LEAF);
+  }
+
+cleardatabasepage_out:
+  releasePage(pPage);
+  return rc;
+}
+
+/*
+** Delete all information from a single table in the database.  iTable is
+** the page number of the root of the table.  After this routine returns,
+** the root page is empty, but still exists.
+**
+** This routine will fail with SQLITE_LOCKED if there are any open
+** read cursors on the table.  Open write cursors are moved to the
+** root of the table.
+*/
+int sqlite3BtreeClearTable(Btree *p, int iTable){
+  int rc;
+  BtShared *pBt = p->pBt;
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+  if( p->inTrans!=TRANS_WRITE ){
+    rc = pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
+  }else if( (rc = checkReadLocks(p, iTable, 0, 1))!=SQLITE_OK ){
+    /* nothing to do */
+  }else if( SQLITE_OK!=(rc = saveAllCursors(pBt, iTable, 0)) ){
+    /* nothing to do */
+  }else{
+    rc = clearDatabasePage(pBt, (Pgno)iTable, 0, 0);
+  }
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+/*
+** Erase all information in a table and add the root of the table to
+** the freelist.  Except, the root of the principle table (the one on
+** page 1) is never added to the freelist.
+**
+** This routine will fail with SQLITE_LOCKED if there are any open
+** cursors on the table.
+**
+** If AUTOVACUUM is enabled and the page at iTable is not the last
+** root page in the database file, then the last root page 
+** in the database file is moved into the slot formerly occupied by
+** iTable and that last slot formerly occupied by the last root page
+** is added to the freelist instead of iTable.  In this say, all
+** root pages are kept at the beginning of the database file, which
+** is necessary for AUTOVACUUM to work right.  *piMoved is set to the 
+** page number that used to be the last root page in the file before
+** the move.  If no page gets moved, *piMoved is set to 0.
+** The last root page is recorded in meta[3] and the value of
+** meta[3] is updated by this procedure.
+*/
+static int btreeDropTable(Btree *p, int iTable, int *piMoved){
+  int rc;
+  MemPage *pPage = 0;
+  BtShared *pBt = p->pBt;
+
+  assert( sqlite3BtreeHoldsMutex(p) );
+  if( p->inTrans!=TRANS_WRITE ){
+    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
+  }
+
+  /* It is illegal to drop a table if any cursors are open on the
+  ** database. This is because in auto-vacuum mode the backend may
+  ** need to move another root-page to fill a gap left by the deleted
+  ** root page. If an open cursor was using this page a problem would 
+  ** occur.
+  */
+  if( pBt->pCursor ){
+    return SQLITE_LOCKED;
+  }
+
+  rc = sqlite3BtreeGetPage(pBt, (Pgno)iTable, &pPage, 0);
+  if( rc ) return rc;
+  rc = sqlite3BtreeClearTable(p, iTable);
+  if( rc ){
+    releasePage(pPage);
+    return rc;
+  }
+
+  *piMoved = 0;
+
+  if( iTable>1 ){
+#ifdef SQLITE_OMIT_AUTOVACUUM
+    rc = freePage(pPage);
+    releasePage(pPage);
+#else
+    if( pBt->autoVacuum ){
+      Pgno maxRootPgno;
+      rc = sqlite3BtreeGetMeta(p, 4, &maxRootPgno);
+      if( rc!=SQLITE_OK ){
+        releasePage(pPage);
+        return rc;
+      }
+
+      if( iTable==maxRootPgno ){
+        /* If the table being dropped is the table with the largest root-page
+        ** number in the database, put the root page on the free list. 
+        */
+        rc = freePage(pPage);
+        releasePage(pPage);
+        if( rc!=SQLITE_OK ){
+          return rc;
+        }
+      }else{
+        /* The table being dropped does not have the largest root-page
+        ** number in the database. So move the page that does into the 
+        ** gap left by the deleted root-page.
+        */
+        MemPage *pMove;
+        releasePage(pPage);
+        rc = sqlite3BtreeGetPage(pBt, maxRootPgno, &pMove, 0);
+        if( rc!=SQLITE_OK ){
+          return rc;
+        }
+        rc = relocatePage(pBt, pMove, PTRMAP_ROOTPAGE, 0, iTable, 0);
+        releasePage(pMove);
+        if( rc!=SQLITE_OK ){
+          return rc;
+        }
+        rc = sqlite3BtreeGetPage(pBt, maxRootPgno, &pMove, 0);
+        if( rc!=SQLITE_OK ){
+          return rc;
+        }
+        rc = freePage(pMove);
+        releasePage(pMove);
+        if( rc!=SQLITE_OK ){
+          return rc;
+        }
+        *piMoved = maxRootPgno;
+      }
+
+      /* Set the new 'max-root-page' value in the database header. This
+      ** is the old value less one, less one more if that happens to
+      ** be a root-page number, less one again if that is the
+      ** PENDING_BYTE_PAGE.
+      */
+      maxRootPgno--;
+      if( maxRootPgno==PENDING_BYTE_PAGE(pBt) ){
+        maxRootPgno--;
+      }
+      if( maxRootPgno==PTRMAP_PAGENO(pBt, maxRootPgno) ){
+        maxRootPgno--;
+      }
+      assert( maxRootPgno!=PENDING_BYTE_PAGE(pBt) );
+
+      rc = sqlite3BtreeUpdateMeta(p, 4, maxRootPgno);
+    }else{
+      rc = freePage(pPage);
+      releasePage(pPage);
+    }
+#endif
+  }else{
+    /* If sqlite3BtreeDropTable was called on page 1. */
+    zeroPage(pPage, PTF_INTKEY|PTF_LEAF );
+    releasePage(pPage);
+  }
+  return rc;  
+}
+int sqlite3BtreeDropTable(Btree *p, int iTable, int *piMoved){
+  int rc;
+  sqlite3BtreeEnter(p);
+  p->pBt->db = p->db;
+  rc = btreeDropTable(p, iTable, piMoved);
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+
+/*
+** Read the meta-information out of a database file.  Meta[0]
+** is the number of free pages currently in the database.  Meta[1]
+** through meta[15] are available for use by higher layers.  Meta[0]
+** is read-only, the others are read/write.
+** 
+** The schema layer numbers meta values differently.  At the schema
+** layer (and the SetCookie and ReadCookie opcodes) the number of
+** free pages is not visible.  So Cookie[0] is the same as Meta[1].
+*/
+int sqlite3BtreeGetMeta(Btree *p, int idx, u32 *pMeta){
+  DbPage *pDbPage;
+  int rc;
+  unsigned char *pP1;
+  BtShared *pBt = p->pBt;
+
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+
+  /* Reading a meta-data value requires a read-lock on page 1 (and hence
+  ** the sqlite_master table. We grab this lock regardless of whether or
+  ** not the SQLITE_ReadUncommitted flag is set (the table rooted at page
+  ** 1 is treated as a special case by queryTableLock() and lockTable()).
+  */
+  rc = queryTableLock(p, 1, READ_LOCK);
+  if( rc!=SQLITE_OK ){
+    sqlite3BtreeLeave(p);
+    return rc;
+  }
+
+  assert( idx>=0 && idx<=15 );
+  rc = sqlite3PagerGet(pBt->pPager, 1, &pDbPage);
+  if( rc ){
+    sqlite3BtreeLeave(p);
+    return rc;
+  }
+  pP1 = (unsigned char *)sqlite3PagerGetData(pDbPage);
+  *pMeta = get4byte(&pP1[36 + idx*4]);
+  sqlite3PagerUnref(pDbPage);
+
+  /* If autovacuumed is disabled in this build but we are trying to 
+  ** access an autovacuumed database, then make the database readonly. 
+  */
+#ifdef SQLITE_OMIT_AUTOVACUUM
+  if( idx==4 && *pMeta>0 ) pBt->readOnly = 1;
+#endif
+
+  /* Grab the read-lock on page 1. */
+  rc = lockTable(p, 1, READ_LOCK);
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+/*
+** Write meta-information back into the database.  Meta[0] is
+** read-only and may not be written.
+*/
+int sqlite3BtreeUpdateMeta(Btree *p, int idx, u32 iMeta){
+  BtShared *pBt = p->pBt;
+  unsigned char *pP1;
+  int rc;
+  assert( idx>=1 && idx<=15 );
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+  if( p->inTrans!=TRANS_WRITE ){
+    rc = pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
+  }else{
+    assert( pBt->pPage1!=0 );
+    pP1 = pBt->pPage1->aData;
+    rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
+    if( rc==SQLITE_OK ){
+      put4byte(&pP1[36 + idx*4], iMeta);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+      if( idx==7 ){
+        assert( pBt->autoVacuum || iMeta==0 );
+        assert( iMeta==0 || iMeta==1 );
+        pBt->incrVacuum = iMeta;
+      }
+#endif
+    }
+  }
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+/*
+** Return the flag byte at the beginning of the page that the cursor
+** is currently pointing to.
+*/
+int sqlite3BtreeFlags(BtCursor *pCur){
+  /* TODO: What about CURSOR_REQUIRESEEK state? Probably need to call
+  ** restoreCursorPosition() here.
+  */
+  MemPage *pPage;
+  restoreCursorPosition(pCur);
+  pPage = pCur->pPage;
+  assert( cursorHoldsMutex(pCur) );
+  assert( pPage->pBt==pCur->pBt );
+  return pPage ? pPage->aData[pPage->hdrOffset] : 0;
+}
+
+
+/*
+** Return the pager associated with a BTree.  This routine is used for
+** testing and debugging only.
+*/
+Pager *sqlite3BtreePager(Btree *p){
+  return p->pBt->pPager;
+}
+
+#ifndef SQLITE_OMIT_INTEGRITY_CHECK
+/*
+** Append a message to the error message string.
+*/
+static void checkAppendMsg(
+  IntegrityCk *pCheck,
+  char *zMsg1,
+  const char *zFormat,
+  ...
+){
+  va_list ap;
+  if( !pCheck->mxErr ) return;
+  pCheck->mxErr--;
+  pCheck->nErr++;
+  va_start(ap, zFormat);
+  if( pCheck->errMsg.nChar ){
+    sqlite3StrAccumAppend(&pCheck->errMsg, "\n", 1);
+  }
+  if( zMsg1 ){
+    sqlite3StrAccumAppend(&pCheck->errMsg, zMsg1, -1);
+  }
+  sqlite3VXPrintf(&pCheck->errMsg, 1, zFormat, ap);
+  va_end(ap);
+  if( pCheck->errMsg.mallocFailed ){
+    pCheck->mallocFailed = 1;
+  }
+}
+#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
+
+#ifndef SQLITE_OMIT_INTEGRITY_CHECK
+/*
+** Add 1 to the reference count for page iPage.  If this is the second
+** reference to the page, add an error message to pCheck->zErrMsg.
+** Return 1 if there are 2 ore more references to the page and 0 if
+** if this is the first reference to the page.
+**
+** Also check that the page number is in bounds.
+*/
+static int checkRef(IntegrityCk *pCheck, int iPage, char *zContext){
+  if( iPage==0 ) return 1;
+  if( iPage>pCheck->nPage || iPage<0 ){
+    checkAppendMsg(pCheck, zContext, "invalid page number %d", iPage);
+    return 1;
+  }
+  if( pCheck->anRef[iPage]==1 ){
+    checkAppendMsg(pCheck, zContext, "2nd reference to page %d", iPage);
+    return 1;
+  }
+  return  (pCheck->anRef[iPage]++)>1;
+}
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+/*
+** Check that the entry in the pointer-map for page iChild maps to 
+** page iParent, pointer type ptrType. If not, append an error message
+** to pCheck.
+*/
+static void checkPtrmap(
+  IntegrityCk *pCheck,   /* Integrity check context */
+  Pgno iChild,           /* Child page number */
+  u8 eType,              /* Expected pointer map type */
+  Pgno iParent,          /* Expected pointer map parent page number */
+  char *zContext         /* Context description (used for error msg) */
+){
+  int rc;
+  u8 ePtrmapType;
+  Pgno iPtrmapParent;
+
+  rc = ptrmapGet(pCheck->pBt, iChild, &ePtrmapType, &iPtrmapParent);
+  if( rc!=SQLITE_OK ){
+    checkAppendMsg(pCheck, zContext, "Failed to read ptrmap key=%d", iChild);
+    return;
+  }
+
+  if( ePtrmapType!=eType || iPtrmapParent!=iParent ){
+    checkAppendMsg(pCheck, zContext, 
+      "Bad ptr map entry key=%d expected=(%d,%d) got=(%d,%d)", 
+      iChild, eType, iParent, ePtrmapType, iPtrmapParent);
+  }
+}
+#endif
+
+/*
+** Check the integrity of the freelist or of an overflow page list.
+** Verify that the number of pages on the list is N.
+*/
+static void checkList(
+  IntegrityCk *pCheck,  /* Integrity checking context */
+  int isFreeList,       /* True for a freelist.  False for overflow page list */
+  int iPage,            /* Page number for first page in the list */
+  int N,                /* Expected number of pages in the list */
+  char *zContext        /* Context for error messages */
+){
+  int i;
+  int expected = N;
+  int iFirst = iPage;
+  while( N-- > 0 && pCheck->mxErr ){
+    DbPage *pOvflPage;
+    unsigned char *pOvflData;
+    if( iPage<1 ){
+      checkAppendMsg(pCheck, zContext,
+         "%d of %d pages missing from overflow list starting at %d",
+          N+1, expected, iFirst);
+      break;
+    }
+    if( checkRef(pCheck, iPage, zContext) ) break;
+    if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage) ){
+      checkAppendMsg(pCheck, zContext, "failed to get page %d", iPage);
+      break;
+    }
+    pOvflData = (unsigned char *)sqlite3PagerGetData(pOvflPage);
+    if( isFreeList ){
+      int n = get4byte(&pOvflData[4]);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+      if( pCheck->pBt->autoVacuum ){
+        checkPtrmap(pCheck, iPage, PTRMAP_FREEPAGE, 0, zContext);
+      }
+#endif
+      if( n>pCheck->pBt->usableSize/4-2 ){
+        checkAppendMsg(pCheck, zContext,
+           "freelist leaf count too big on page %d", iPage);
+        N--;
+      }else{
+        for(i=0; i<n; i++){
+          Pgno iFreePage = get4byte(&pOvflData[8+i*4]);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+          if( pCheck->pBt->autoVacuum ){
+            checkPtrmap(pCheck, iFreePage, PTRMAP_FREEPAGE, 0, zContext);
+          }
+#endif
+          checkRef(pCheck, iFreePage, zContext);
+        }
+        N -= n;
+      }
+    }
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    else{
+      /* If this database supports auto-vacuum and iPage is not the last
+      ** page in this overflow list, check that the pointer-map entry for
+      ** the following page matches iPage.
+      */
+      if( pCheck->pBt->autoVacuum && N>0 ){
+        i = get4byte(pOvflData);
+        checkPtrmap(pCheck, i, PTRMAP_OVERFLOW2, iPage, zContext);
+      }
+    }
+#endif
+    iPage = get4byte(pOvflData);
+    sqlite3PagerUnref(pOvflPage);
+  }
+}
+#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
+
+#ifndef SQLITE_OMIT_INTEGRITY_CHECK
+/*
+** Do various sanity checks on a single page of a tree.  Return
+** the tree depth.  Root pages return 0.  Parents of root pages
+** return 1, and so forth.
+** 
+** These checks are done:
+**
+**      1.  Make sure that cells and freeblocks do not overlap
+**          but combine to completely cover the page.
+**  NO  2.  Make sure cell keys are in order.
+**  NO  3.  Make sure no key is less than or equal to zLowerBound.
+**  NO  4.  Make sure no key is greater than or equal to zUpperBound.
+**      5.  Check the integrity of overflow pages.
+**      6.  Recursively call checkTreePage on all children.
+**      7.  Verify that the depth of all children is the same.
+**      8.  Make sure this page is at least 33% full or else it is
+**          the root of the tree.
+*/
+static int checkTreePage(
+  IntegrityCk *pCheck,  /* Context for the sanity check */
+  int iPage,            /* Page number of the page to check */
+  MemPage *pParent,     /* Parent page */
+  char *zParentContext  /* Parent context */
+){
+  MemPage *pPage;
+  int i, rc, depth, d2, pgno, cnt;
+  int hdr, cellStart;
+  int nCell;
+  u8 *data;
+  BtShared *pBt;
+  int usableSize;
+  char zContext[100];
+  char *hit;
+
+  sqlite3_snprintf(sizeof(zContext), zContext, "Page %d: ", iPage);
+
+  /* Check that the page exists
+  */
+  pBt = pCheck->pBt;
+  usableSize = pBt->usableSize;
+  if( iPage==0 ) return 0;
+  if( checkRef(pCheck, iPage, zParentContext) ) return 0;
+  if( (rc = sqlite3BtreeGetPage(pBt, (Pgno)iPage, &pPage, 0))!=0 ){
+    checkAppendMsg(pCheck, zContext,
+       "unable to get the page. error code=%d", rc);
+    return 0;
+  }
+  if( (rc = sqlite3BtreeInitPage(pPage, pParent))!=0 ){
+    checkAppendMsg(pCheck, zContext, 
+                   "sqlite3BtreeInitPage() returns error code %d", rc);
+    releasePage(pPage);
+    return 0;
+  }
+
+  /* Check out all the cells.
+  */
+  depth = 0;
+  for(i=0; i<pPage->nCell && pCheck->mxErr; i++){
+    u8 *pCell;
+    int sz;
+    CellInfo info;
+
+    /* Check payload overflow pages
+    */
+    sqlite3_snprintf(sizeof(zContext), zContext,
+             "On tree page %d cell %d: ", iPage, i);
+    pCell = findCell(pPage,i);
+    sqlite3BtreeParseCellPtr(pPage, pCell, &info);
+    sz = info.nData;
+    if( !pPage->intKey ) sz += info.nKey;
+    assert( sz==info.nPayload );
+    if( sz>info.nLocal ){
+      int nPage = (sz - info.nLocal + usableSize - 5)/(usableSize - 4);
+      Pgno pgnoOvfl = get4byte(&pCell[info.iOverflow]);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+      if( pBt->autoVacuum ){
+        checkPtrmap(pCheck, pgnoOvfl, PTRMAP_OVERFLOW1, iPage, zContext);
+      }
+#endif
+      checkList(pCheck, 0, pgnoOvfl, nPage, zContext);
+    }
+
+    /* Check sanity of left child page.
+    */
+    if( !pPage->leaf ){
+      pgno = get4byte(pCell);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+      if( pBt->autoVacuum ){
+        checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage, zContext);
+      }
+#endif
+      d2 = checkTreePage(pCheck,pgno,pPage,zContext);
+      if( i>0 && d2!=depth ){
+        checkAppendMsg(pCheck, zContext, "Child page depth differs");
+      }
+      depth = d2;
+    }
+  }
+  if( !pPage->leaf ){
+    pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
+    sqlite3_snprintf(sizeof(zContext), zContext, 
+                     "On page %d at right child: ", iPage);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    if( pBt->autoVacuum ){
+      checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage, 0);
+    }
+#endif
+    checkTreePage(pCheck, pgno, pPage, zContext);
+  }
+ 
+  /* Check for complete coverage of the page
+  */
+  data = pPage->aData;
+  hdr = pPage->hdrOffset;
+  hit = sqlite3PageMalloc( pBt->pageSize );
+  if( hit==0 ){
+    pCheck->mallocFailed = 1;
+  }else{
+    memset(hit, 0, usableSize );
+    memset(hit, 1, get2byte(&data[hdr+5]));
+    nCell = get2byte(&data[hdr+3]);
+    cellStart = hdr + 12 - 4*pPage->leaf;
+    for(i=0; i<nCell; i++){
+      int pc = get2byte(&data[cellStart+i*2]);
+      u16 size = cellSizePtr(pPage, &data[pc]);
+      int j;
+      if( (pc+size-1)>=usableSize || pc<0 ){
+        checkAppendMsg(pCheck, 0, 
+            "Corruption detected in cell %d on page %d",i,iPage,0);
+      }else{
+        for(j=pc+size-1; j>=pc; j--) hit[j]++;
+      }
+    }
+    for(cnt=0, i=get2byte(&data[hdr+1]); i>0 && i<usableSize && cnt<10000; 
+           cnt++){
+      int size = get2byte(&data[i+2]);
+      int j;
+      if( (i+size-1)>=usableSize || i<0 ){
+        checkAppendMsg(pCheck, 0,  
+            "Corruption detected in cell %d on page %d",i,iPage,0);
+      }else{
+        for(j=i+size-1; j>=i; j--) hit[j]++;
+      }
+      i = get2byte(&data[i]);
+    }
+    for(i=cnt=0; i<usableSize; i++){
+      if( hit[i]==0 ){
+        cnt++;
+      }else if( hit[i]>1 ){
+        checkAppendMsg(pCheck, 0,
+          "Multiple uses for byte %d of page %d", i, iPage);
+        break;
+      }
+    }
+    if( cnt!=data[hdr+7] ){
+      checkAppendMsg(pCheck, 0, 
+          "Fragmented space is %d byte reported as %d on page %d",
+          cnt, data[hdr+7], iPage);
+    }
+  }
+  sqlite3PageFree(hit);
+
+  releasePage(pPage);
+  return depth+1;
+}
+#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
+
+#ifndef SQLITE_OMIT_INTEGRITY_CHECK
+/*
+** This routine does a complete check of the given BTree file.  aRoot[] is
+** an array of pages numbers were each page number is the root page of
+** a table.  nRoot is the number of entries in aRoot.
+**
+** Write the number of error seen in *pnErr.  Except for some memory
+** allocation errors,  nn error message is held in memory obtained from
+** malloc is returned if *pnErr is non-zero.  If *pnErr==0 then NULL is
+** returned.
+*/
+char *sqlite3BtreeIntegrityCheck(
+  Btree *p,     /* The btree to be checked */
+  int *aRoot,   /* An array of root pages numbers for individual trees */
+  int nRoot,    /* Number of entries in aRoot[] */
+  int mxErr,    /* Stop reporting errors after this many */
+  int *pnErr    /* Write number of errors seen to this variable */
+){
+  int i;
+  int nRef;
+  IntegrityCk sCheck;
+  BtShared *pBt = p->pBt;
+  char zErr[100];
+
+  sqlite3BtreeEnter(p);
+  pBt->db = p->db;
+  nRef = sqlite3PagerRefcount(pBt->pPager);
+  if( lockBtreeWithRetry(p)!=SQLITE_OK ){
+    *pnErr = 1;
+    sqlite3BtreeLeave(p);
+    return sqlite3DbStrDup(0, "cannot acquire a read lock on the database");
+  }
+  sCheck.pBt = pBt;
+  sCheck.pPager = pBt->pPager;
+  sCheck.nPage = pagerPagecount(sCheck.pPager);
+  sCheck.mxErr = mxErr;
+  sCheck.nErr = 0;
+  sCheck.mallocFailed = 0;
+  *pnErr = 0;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+  if( pBt->nTrunc!=0 ){
+    sCheck.nPage = pBt->nTrunc;
+  }
+#endif
+  if( sCheck.nPage==0 ){
+    unlockBtreeIfUnused(pBt);
+    sqlite3BtreeLeave(p);
+    return 0;
+  }
+  sCheck.anRef = sqlite3Malloc( (sCheck.nPage+1)*sizeof(sCheck.anRef[0]) );
+  if( !sCheck.anRef ){
+    unlockBtreeIfUnused(pBt);
+    *pnErr = 1;
+    sqlite3BtreeLeave(p);
+    return 0;
+  }
+  for(i=0; i<=sCheck.nPage; i++){ sCheck.anRef[i] = 0; }
+  i = PENDING_BYTE_PAGE(pBt);
+  if( i<=sCheck.nPage ){
+    sCheck.anRef[i] = 1;
+  }
+  sqlite3StrAccumInit(&sCheck.errMsg, zErr, sizeof(zErr), 20000);
+
+  /* Check the integrity of the freelist
+  */
+  checkList(&sCheck, 1, get4byte(&pBt->pPage1->aData[32]),
+            get4byte(&pBt->pPage1->aData[36]), "Main freelist: ");
+
+  /* Check all the tables.
+  */
+  for(i=0; i<nRoot && sCheck.mxErr; i++){
+    if( aRoot[i]==0 ) continue;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    if( pBt->autoVacuum && aRoot[i]>1 ){
+      checkPtrmap(&sCheck, aRoot[i], PTRMAP_ROOTPAGE, 0, 0);
+    }
+#endif
+    checkTreePage(&sCheck, aRoot[i], 0, "List of tree roots: ");
+  }
+
+  /* Make sure every page in the file is referenced
+  */
+  for(i=1; i<=sCheck.nPage && sCheck.mxErr; i++){
+#ifdef SQLITE_OMIT_AUTOVACUUM
+    if( sCheck.anRef[i]==0 ){
+      checkAppendMsg(&sCheck, 0, "Page %d is never used", i);
+    }
+#else
+    /* If the database supports auto-vacuum, make sure no tables contain
+    ** references to pointer-map pages.
+    */
+    if( sCheck.anRef[i]==0 && 
+       (PTRMAP_PAGENO(pBt, i)!=i || !pBt->autoVacuum) ){
+      checkAppendMsg(&sCheck, 0, "Page %d is never used", i);
+    }
+    if( sCheck.anRef[i]!=0 && 
+       (PTRMAP_PAGENO(pBt, i)==i && pBt->autoVacuum) ){
+      checkAppendMsg(&sCheck, 0, "Pointer map page %d is referenced", i);
+    }
+#endif
+  }
+
+  /* Make sure this analysis did not leave any unref() pages
+  */
+  unlockBtreeIfUnused(pBt);
+  if( nRef != sqlite3PagerRefcount(pBt->pPager) ){
+    checkAppendMsg(&sCheck, 0, 
+      "Outstanding page count goes from %d to %d during this analysis",
+      nRef, sqlite3PagerRefcount(pBt->pPager)
+    );
+  }
+
+  /* Clean  up and report errors.
+  */
+  sqlite3BtreeLeave(p);
+  sqlite3_free(sCheck.anRef);
+  if( sCheck.mallocFailed ){
+    sqlite3StrAccumReset(&sCheck.errMsg);
+    *pnErr = sCheck.nErr+1;
+    return 0;
+  }
+  *pnErr = sCheck.nErr;
+  if( sCheck.nErr==0 ) sqlite3StrAccumReset(&sCheck.errMsg);
+  return sqlite3StrAccumFinish(&sCheck.errMsg);
+}
+#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
+
+/*
+** Return the full pathname of the underlying database file.
+**
+** The pager filename is invariant as long as the pager is
+** open so it is safe to access without the BtShared mutex.
+*/
+const char *sqlite3BtreeGetFilename(Btree *p){
+  assert( p->pBt->pPager!=0 );
+  return sqlite3PagerFilename(p->pBt->pPager);
+}
+
+/*
+** Return the pathname of the directory that contains the database file.
+**
+** The pager directory name is invariant as long as the pager is
+** open so it is safe to access without the BtShared mutex.
+*/
+const char *sqlite3BtreeGetDirname(Btree *p){
+  assert( p->pBt->pPager!=0 );
+  return sqlite3PagerDirname(p->pBt->pPager);
+}
+
+/*
+** Return the pathname of the journal file for this database. The return
+** value of this routine is the same regardless of whether the journal file
+** has been created or not.
+**
+** The pager journal filename is invariant as long as the pager is
+** open so it is safe to access without the BtShared mutex.
+*/
+const char *sqlite3BtreeGetJournalname(Btree *p){
+  assert( p->pBt->pPager!=0 );
+  return sqlite3PagerJournalname(p->pBt->pPager);
+}
+
+#ifndef SQLITE_OMIT_VACUUM
+/*
+** Copy the complete content of pBtFrom into pBtTo.  A transaction
+** must be active for both files.
+**
+** The size of file pTo may be reduced by this operation.
+** If anything goes wrong, the transaction on pTo is rolled back. 
+**
+** If successful, CommitPhaseOne() may be called on pTo before returning. 
+** The caller should finish committing the transaction on pTo by calling
+** sqlite3BtreeCommit().
+*/
+static int btreeCopyFile(Btree *pTo, Btree *pFrom){
+  int rc = SQLITE_OK;
+  Pgno i;
+
+  Pgno nFromPage;     /* Number of pages in pFrom */
+  Pgno nToPage;       /* Number of pages in pTo */
+  Pgno nNewPage;      /* Number of pages in pTo after the copy */
+
+  Pgno iSkip;         /* Pending byte page in pTo */
+  int nToPageSize;    /* Page size of pTo in bytes */
+  int nFromPageSize;  /* Page size of pFrom in bytes */
+
+  BtShared *pBtTo = pTo->pBt;
+  BtShared *pBtFrom = pFrom->pBt;
+  pBtTo->db = pTo->db;
+  pBtFrom->db = pFrom->db;
+
+  nToPageSize = pBtTo->pageSize;
+  nFromPageSize = pBtFrom->pageSize;
+
+  if( pTo->inTrans!=TRANS_WRITE || pFrom->inTrans!=TRANS_WRITE ){
+    return SQLITE_ERROR;
+  }
+  if( pBtTo->pCursor ){
+    return SQLITE_BUSY;
+  }
+
+  nToPage = pagerPagecount(pBtTo->pPager);
+  nFromPage = pagerPagecount(pBtFrom->pPager);
+  iSkip = PENDING_BYTE_PAGE(pBtTo);
+
+  /* Variable nNewPage is the number of pages required to store the
+  ** contents of pFrom using the current page-size of pTo.
+  */
+  nNewPage = ((i64)nFromPage * (i64)nFromPageSize + (i64)nToPageSize - 1) / 
+      (i64)nToPageSize;
+
+  for(i=1; rc==SQLITE_OK && (i<=nToPage || i<=nNewPage); i++){
+
+    /* Journal the original page.
+    **
+    ** iSkip is the page number of the locking page (PENDING_BYTE_PAGE)
+    ** in database *pTo (before the copy). This page is never written 
+    ** into the journal file. Unless i==iSkip or the page was not
+    ** present in pTo before the copy operation, journal page i from pTo.
+    */
+    if( i!=iSkip && i<=nToPage ){
+      DbPage *pDbPage = 0;
+      rc = sqlite3PagerGet(pBtTo->pPager, i, &pDbPage);
+      if( rc==SQLITE_OK ){
+        rc = sqlite3PagerWrite(pDbPage);
+        if( rc==SQLITE_OK && i>nFromPage ){
+          /* Yeah.  It seems wierd to call DontWrite() right after Write(). But
+          ** that is because the names of those procedures do not exactly 
+          ** represent what they do.  Write() really means "put this page in the
+          ** rollback journal and mark it as dirty so that it will be written
+          ** to the database file later."  DontWrite() undoes the second part of
+          ** that and prevents the page from being written to the database. The
+          ** page is still on the rollback journal, though.  And that is the 
+          ** whole point of this block: to put pages on the rollback journal. 
+          */
+          sqlite3PagerDontWrite(pDbPage);
+        }
+        sqlite3PagerUnref(pDbPage);
+      }
+    }
+
+    /* Overwrite the data in page i of the target database */
+    if( rc==SQLITE_OK && i!=iSkip && i<=nNewPage ){
+
+      DbPage *pToPage = 0;
+      sqlite3_int64 iOff;
+
+      rc = sqlite3PagerGet(pBtTo->pPager, i, &pToPage);
+      if( rc==SQLITE_OK ){
+        rc = sqlite3PagerWrite(pToPage);
+      }
+
+      for(
+        iOff=(i-1)*nToPageSize; 
+        rc==SQLITE_OK && iOff<i*nToPageSize; 
+        iOff += nFromPageSize
+      ){
+        DbPage *pFromPage = 0;
+        Pgno iFrom = (iOff/nFromPageSize)+1;
+
+        if( iFrom==PENDING_BYTE_PAGE(pBtFrom) ){
+          continue;
+        }
+
+        rc = sqlite3PagerGet(pBtFrom->pPager, iFrom, &pFromPage);
+        if( rc==SQLITE_OK ){
+          char *zTo = sqlite3PagerGetData(pToPage);
+          char *zFrom = sqlite3PagerGetData(pFromPage);
+          int nCopy;
+
+          if( nFromPageSize>=nToPageSize ){
+            zFrom += ((i-1)*nToPageSize - ((iFrom-1)*nFromPageSize));
+            nCopy = nToPageSize;
+          }else{
+            zTo += (((iFrom-1)*nFromPageSize) - (i-1)*nToPageSize);
+            nCopy = nFromPageSize;
+          }
+
+          memcpy(zTo, zFrom, nCopy);
+	  sqlite3PagerUnref(pFromPage);
+        }
+      }
+
+      if( pToPage ) sqlite3PagerUnref(pToPage);
+    }
+  }
+
+  /* If things have worked so far, the database file may need to be 
+  ** truncated. The complex part is that it may need to be truncated to
+  ** a size that is not an integer multiple of nToPageSize - the current
+  ** page size used by the pager associated with B-Tree pTo.
+  **
+  ** For example, say the page-size of pTo is 2048 bytes and the original 
+  ** number of pages is 5 (10 KB file). If pFrom has a page size of 1024 
+  ** bytes and 9 pages, then the file needs to be truncated to 9KB.
+  */
+  if( rc==SQLITE_OK ){
+    if( nFromPageSize!=nToPageSize ){
+      sqlite3_file *pFile = sqlite3PagerFile(pBtTo->pPager);
+      i64 iSize = (i64)nFromPageSize * (i64)nFromPage;
+      i64 iNow = (i64)((nToPage>nNewPage)?nToPage:nNewPage) * (i64)nToPageSize; 
+      i64 iPending = ((i64)PENDING_BYTE_PAGE(pBtTo)-1) *(i64)nToPageSize;
+  
+      assert( iSize<=iNow );
+  
+      /* Commit phase one syncs the journal file associated with pTo 
+      ** containing the original data. It does not sync the database file
+      ** itself. After doing this it is safe to use OsTruncate() and other
+      ** file APIs on the database file directly.
+      */
+      pBtTo->db = pTo->db;
+      rc = sqlite3PagerCommitPhaseOne(pBtTo->pPager, 0, 0, 1);
+      if( iSize<iNow && rc==SQLITE_OK ){
+        rc = sqlite3OsTruncate(pFile, iSize);
+      }
+  
+      /* The loop that copied data from database pFrom to pTo did not
+      ** populate the locking page of database pTo. If the page-size of
+      ** pFrom is smaller than that of pTo, this means some data will
+      ** not have been copied. 
+      **
+      ** This block copies the missing data from database pFrom to pTo 
+      ** using file APIs. This is safe because at this point we know that
+      ** all of the original data from pTo has been synced into the 
+      ** journal file. At this point it would be safe to do anything at
+      ** all to the database file except truncate it to zero bytes.
+      */
+      if( rc==SQLITE_OK && nFromPageSize<nToPageSize && iSize>iPending){
+        i64 iOff;
+        for(
+          iOff=iPending; 
+          rc==SQLITE_OK && iOff<(iPending+nToPageSize); 
+          iOff += nFromPageSize
+        ){
+          DbPage *pFromPage = 0;
+          Pgno iFrom = (iOff/nFromPageSize)+1;
+  
+          if( iFrom==PENDING_BYTE_PAGE(pBtFrom) || iFrom>nFromPage ){
+            continue;
+          }
+  
+          rc = sqlite3PagerGet(pBtFrom->pPager, iFrom, &pFromPage);
+          if( rc==SQLITE_OK ){
+            char *zFrom = sqlite3PagerGetData(pFromPage);
+  	  rc = sqlite3OsWrite(pFile, zFrom, nFromPageSize, iOff);
+            sqlite3PagerUnref(pFromPage);
+          }
+        }
+      }
+  
+      /* Sync the database file */
+      if( rc==SQLITE_OK ){
+        rc = sqlite3PagerSync(pBtTo->pPager);
+      }
+    }else{
+      rc = sqlite3PagerTruncate(pBtTo->pPager, nNewPage);
+    }
+    if( rc==SQLITE_OK ){
+      pBtTo->pageSizeFixed = 0;
+    }
+  }
+
+  if( rc ){
+    sqlite3BtreeRollback(pTo);
+  }
+
+  return rc;  
+}
+int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
+  int rc;
+  sqlite3BtreeEnter(pTo);
+  sqlite3BtreeEnter(pFrom);
+  rc = btreeCopyFile(pTo, pFrom);
+  sqlite3BtreeLeave(pFrom);
+  sqlite3BtreeLeave(pTo);
+  return rc;
+}
+
+#endif /* SQLITE_OMIT_VACUUM */
+
+/*
+** Return non-zero if a transaction is active.
+*/
+int sqlite3BtreeIsInTrans(Btree *p){
+  assert( p==0 || sqlite3_mutex_held(p->db->mutex) );
+  return (p && (p->inTrans==TRANS_WRITE));
+}
+
+/*
+** Return non-zero if a statement transaction is active.
+*/
+int sqlite3BtreeIsInStmt(Btree *p){
+  assert( sqlite3BtreeHoldsMutex(p) );
+  return (p->pBt && p->pBt->inStmt);
+}
+
+/*
+** Return non-zero if a read (or write) transaction is active.
+*/
+int sqlite3BtreeIsInReadTrans(Btree *p){
+  assert( sqlite3_mutex_held(p->db->mutex) );
+  return (p && (p->inTrans!=TRANS_NONE));
+}
+
+/*
+** This function returns a pointer to a blob of memory associated with
+** a single shared-btree. The memory is used by client code for its own
+** purposes (for example, to store a high-level schema associated with 
+** the shared-btree). The btree layer manages reference counting issues.
+**
+** The first time this is called on a shared-btree, nBytes bytes of memory
+** are allocated, zeroed, and returned to the caller. For each subsequent 
+** call the nBytes parameter is ignored and a pointer to the same blob
+** of memory returned. 
+**
+** If the nBytes parameter is 0 and the blob of memory has not yet been
+** allocated, a null pointer is returned. If the blob has already been
+** allocated, it is returned as normal.
+**
+** Just before the shared-btree is closed, the function passed as the 
+** xFree argument when the memory allocation was made is invoked on the 
+** blob of allocated memory. This function should not call sqlite3_free()
+** on the memory, the btree layer does that.
+*/
+void *sqlite3BtreeSchema(Btree *p, int nBytes, void(*xFree)(void *)){
+  BtShared *pBt = p->pBt;
+  sqlite3BtreeEnter(p);
+  if( !pBt->pSchema && nBytes ){
+    pBt->pSchema = sqlite3MallocZero(nBytes);
+    pBt->xFreeSchema = xFree;
+  }
+  sqlite3BtreeLeave(p);
+  return pBt->pSchema;
+}
+
+/*
+** Return true if another user of the same shared btree as the argument
+** handle holds an exclusive lock on the sqlite_master table.
+*/
+int sqlite3BtreeSchemaLocked(Btree *p){
+  int rc;
+  assert( sqlite3_mutex_held(p->db->mutex) );
+  sqlite3BtreeEnter(p);
+  rc = (queryTableLock(p, MASTER_ROOT, READ_LOCK)!=SQLITE_OK);
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+
+#ifndef SQLITE_OMIT_SHARED_CACHE
+/*
+** Obtain a lock on the table whose root page is iTab.  The
+** lock is a write lock if isWritelock is true or a read lock
+** if it is false.
+*/
+int sqlite3BtreeLockTable(Btree *p, int iTab, u8 isWriteLock){
+  int rc = SQLITE_OK;
+  if( p->sharable ){
+    u8 lockType = READ_LOCK + isWriteLock;
+    assert( READ_LOCK+1==WRITE_LOCK );
+    assert( isWriteLock==0 || isWriteLock==1 );
+    sqlite3BtreeEnter(p);
+    rc = queryTableLock(p, iTab, lockType);
+    if( rc==SQLITE_OK ){
+      rc = lockTable(p, iTab, lockType);
+    }
+    sqlite3BtreeLeave(p);
+  }
+  return rc;
+}
+#endif
+
+#ifndef SQLITE_OMIT_INCRBLOB
+/*
+** Argument pCsr must be a cursor opened for writing on an 
+** INTKEY table currently pointing at a valid table entry. 
+** This function modifies the data stored as part of that entry.
+** Only the data content may only be modified, it is not possible
+** to change the length of the data stored.
+*/
+int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void *z){
+  assert( cursorHoldsMutex(pCsr) );
+  assert( sqlite3_mutex_held(pCsr->pBtree->db->mutex) );
+  assert(pCsr->isIncrblobHandle);
+
+  restoreCursorPosition(pCsr);
+  assert( pCsr->eState!=CURSOR_REQUIRESEEK );
+  if( pCsr->eState!=CURSOR_VALID ){
+    return SQLITE_ABORT;
+  }
+
+  /* Check some preconditions: 
+  **   (a) the cursor is open for writing,
+  **   (b) there is no read-lock on the table being modified and
+  **   (c) the cursor points at a valid row of an intKey table.
+  */
+  if( !pCsr->wrFlag ){
+    return SQLITE_READONLY;
+  }
+  assert( !pCsr->pBt->readOnly 
+          && pCsr->pBt->inTransaction==TRANS_WRITE );
+  if( checkReadLocks(pCsr->pBtree, pCsr->pgnoRoot, pCsr, 0) ){
+    return SQLITE_LOCKED; /* The table pCur points to has a read lock */
+  }
+  if( pCsr->eState==CURSOR_INVALID || !pCsr->pPage->intKey ){
+    return SQLITE_ERROR;
+  }
+
+  return accessPayload(pCsr, offset, amt, (unsigned char *)z, 0, 1);
+}
+
+/* 
+** Set a flag on this cursor to cache the locations of pages from the 
+** overflow list for the current row. This is used by cursors opened
+** for incremental blob IO only.
+**
+** This function sets a flag only. The actual page location cache
+** (stored in BtCursor.aOverflow[]) is allocated and used by function
+** accessPayload() (the worker function for sqlite3BtreeData() and
+** sqlite3BtreePutData()).
+*/
+void sqlite3BtreeCacheOverflow(BtCursor *pCur){
+  assert( cursorHoldsMutex(pCur) );
+  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
+  assert(!pCur->isIncrblobHandle);
+  assert(!pCur->aOverflow);
+  pCur->isIncrblobHandle = 1;
+}
+
+/* Poison the db so that other clients error out as quickly as
+** possible.
+*/
+int sqlite3Poison(sqlite3 *db){
+  int rc;
+  Btree *p;
+  BtShared *pBt;
+  unsigned char *pP1;
+
+  if( db == NULL) return SQLITE_OK;
+
+  /* Database 0 corrosponds to the main database. */
+  if( db->nDb<1 ) return SQLITE_OK;
+  p = db->aDb[0].pBt;
+  pBt = p->pBt;
+
+  /* If in a transaction, roll it back.  Committing any changes to a
+  ** corrupt database may mess up evidence, we definitely don't want
+  ** to allow poisoning to be rolled back, and the database is anyhow
+  ** going bye-bye RSN.
+  */
+  /* TODO(shess): Figure out if this might release the lock and let
+  ** someone else get in there, which might deny us the lock a couple
+  ** lines down.
+  */
+  if( sqlite3BtreeIsInTrans(p) ) sqlite3BtreeRollback(p);
+
+  /* Start an exclusive transaction.  This will check the headers, so
+  ** if someone else poisoned the database we should get an error.
+  */
+  rc = sqlite3BtreeBeginTrans(p, 2);
+  /* TODO(shess): Handle SQLITE_BUSY? */
+  if( rc!=SQLITE_OK ) return rc;
+
+  /* Copied from sqlite3BtreeUpdateMeta().  Writing the old version of
+  ** the page to the journal may be overkill, but it probably won't
+  ** hurt.
+  */
+  assert( pBt->inTrans==TRANS_WRITE );
+  assert( pBt->pPage1!=0 );
+  rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
+  if( rc ) goto err;
+
+  /* "SQLite format 3" changes to
+  ** "SQLite poison 3".  Be extra paranoid about making this change.
+  */
+  if( sizeof(zMagicHeader)!=16 ||
+      sizeof(zPoisonHeader)!=sizeof(zMagicHeader) ){
+    rc = SQLITE_ERROR;
+    goto err;
+  }
+  pP1 = pBt->pPage1->aData;
+  if( memcmp(pP1, zMagicHeader, 16)!=0 ){
+    rc = SQLITE_CORRUPT;
+    goto err;
+  }
+  memcpy(pP1, zPoisonHeader, 16);
+
+  /* Push it to the database file. */
+  return sqlite3BtreeCommit(p);
+
+ err:
+  /* TODO(shess): What about errors, here? */
+  sqlite3BtreeRollback(p);
+  return rc;
+}
+
+#endif
diff --git a/third_party/sqlite/src/btree.h b/third_party/sqlite/src/btree.h
new file mode 100755
index 0000000..3fe01cb
--- /dev/null
+++ b/third_party/sqlite/src/btree.h
@@ -0,0 +1,219 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This header file defines the interface that the sqlite B-Tree file
+** subsystem.  See comments in the source code for a detailed description
+** of what each interface routine does.
+**
+** @(#) $Id: btree.h,v 1.102 2008/07/11 21:02:54 drh Exp $
+*/
+#ifndef _BTREE_H_
+#define _BTREE_H_
+
+/* TODO: This definition is just included so other modules compile. It
+** needs to be revisited.
+*/
+#define SQLITE_N_BTREE_META 10
+
+/*
+** If defined as non-zero, auto-vacuum is enabled by default. Otherwise
+** it must be turned on for each database using "PRAGMA auto_vacuum = 1".
+*/
+#ifndef SQLITE_DEFAULT_AUTOVACUUM
+  #define SQLITE_DEFAULT_AUTOVACUUM 0
+#endif
+
+#define BTREE_AUTOVACUUM_NONE 0        /* Do not do auto-vacuum */
+#define BTREE_AUTOVACUUM_FULL 1        /* Do full auto-vacuum */
+#define BTREE_AUTOVACUUM_INCR 2        /* Incremental vacuum */
+
+/*
+** Forward declarations of structure
+*/
+typedef struct Btree Btree;
+typedef struct BtCursor BtCursor;
+typedef struct BtShared BtShared;
+typedef struct BtreeMutexArray BtreeMutexArray;
+
+/*
+** This structure records all of the Btrees that need to hold
+** a mutex before we enter sqlite3VdbeExec().  The Btrees are
+** are placed in aBtree[] in order of aBtree[]->pBt.  That way,
+** we can always lock and unlock them all quickly.
+*/
+struct BtreeMutexArray {
+  int nMutex;
+  Btree *aBtree[SQLITE_MAX_ATTACHED+1];
+};
+
+
+int sqlite3BtreeOpen(
+  const char *zFilename,   /* Name of database file to open */
+  sqlite3 *db,             /* Associated database connection */
+  Btree **,                /* Return open Btree* here */
+  int flags,               /* Flags */
+  int vfsFlags             /* Flags passed through to VFS open */
+);
+
+/* The flags parameter to sqlite3BtreeOpen can be the bitwise or of the
+** following values.
+**
+** NOTE:  These values must match the corresponding PAGER_ values in
+** pager.h.
+*/
+#define BTREE_OMIT_JOURNAL  1  /* Do not use journal.  No argument */
+#define BTREE_NO_READLOCK   2  /* Omit readlocks on readonly files */
+#define BTREE_MEMORY        4  /* In-memory DB.  No argument */
+#define BTREE_READONLY      8  /* Open the database in read-only mode */
+#define BTREE_READWRITE    16  /* Open for both reading and writing */
+#define BTREE_CREATE       32  /* Create the database if it does not exist */
+
+int sqlite3BtreeClose(Btree*);
+int sqlite3BtreeSetCacheSize(Btree*,int);
+int sqlite3BtreeSetSafetyLevel(Btree*,int,int);
+int sqlite3BtreeSyncDisabled(Btree*);
+int sqlite3BtreeSetPageSize(Btree*,int,int);
+int sqlite3BtreeGetPageSize(Btree*);
+int sqlite3BtreeMaxPageCount(Btree*,int);
+int sqlite3BtreeGetReserve(Btree*);
+int sqlite3BtreeSetAutoVacuum(Btree *, int);
+int sqlite3BtreeGetAutoVacuum(Btree *);
+int sqlite3BtreeBeginTrans(Btree*,int);
+int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);
+int sqlite3BtreeCommitPhaseTwo(Btree*);
+int sqlite3BtreeCommit(Btree*);
+int sqlite3BtreeRollback(Btree*);
+int sqlite3BtreeBeginStmt(Btree*);
+int sqlite3BtreeCommitStmt(Btree*);
+int sqlite3BtreeRollbackStmt(Btree*);
+int sqlite3BtreeCreateTable(Btree*, int*, int flags);
+int sqlite3BtreeIsInTrans(Btree*);
+int sqlite3BtreeIsInStmt(Btree*);
+int sqlite3BtreeIsInReadTrans(Btree*);
+void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
+int sqlite3BtreeSchemaLocked(Btree *);
+int sqlite3BtreeLockTable(Btree *, int, u8);
+
+const char *sqlite3BtreeGetFilename(Btree *);
+const char *sqlite3BtreeGetDirname(Btree *);
+const char *sqlite3BtreeGetJournalname(Btree *);
+int sqlite3BtreeCopyFile(Btree *, Btree *);
+
+int sqlite3BtreeIncrVacuum(Btree *);
+
+/* The flags parameter to sqlite3BtreeCreateTable can be the bitwise OR
+** of the following flags:
+*/
+#define BTREE_INTKEY     1    /* Table has only 64-bit signed integer keys */
+#define BTREE_ZERODATA   2    /* Table has keys only - no data */
+#define BTREE_LEAFDATA   4    /* Data stored in leaves only.  Implies INTKEY */
+
+int sqlite3BtreeDropTable(Btree*, int, int*);
+int sqlite3BtreeClearTable(Btree*, int);
+int sqlite3BtreeGetMeta(Btree*, int idx, u32 *pValue);
+int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);
+void sqlite3BtreeTripAllCursors(Btree*, int);
+
+struct UnpackedRecord;  /* Forward declaration.  Definition in vdbeaux.c. */
+
+int sqlite3BtreeCursor(
+  Btree*,                              /* BTree containing table to open */
+  int iTable,                          /* Index of root page */
+  int wrFlag,                          /* 1 for writing.  0 for read-only */
+  struct KeyInfo*,                     /* First argument to compare function */
+  BtCursor *pCursor                    /* Space to write cursor structure */
+);
+int sqlite3BtreeCursorSize(void);
+
+int sqlite3BtreeCloseCursor(BtCursor*);
+int sqlite3BtreeMoveto(
+  BtCursor*,
+  const void *pKey,
+  struct UnpackedRecord *pUnKey,
+  i64 nKey,
+  int bias,
+  int *pRes
+);
+int sqlite3BtreeCursorHasMoved(BtCursor*, int*);
+int sqlite3BtreeDelete(BtCursor*);
+int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
+                                  const void *pData, int nData,
+                                  int nZero, int bias);
+int sqlite3BtreeFirst(BtCursor*, int *pRes);
+int sqlite3BtreeLast(BtCursor*, int *pRes);
+int sqlite3BtreeNext(BtCursor*, int *pRes);
+int sqlite3BtreeEof(BtCursor*);
+int sqlite3BtreeFlags(BtCursor*);
+int sqlite3BtreePrevious(BtCursor*, int *pRes);
+int sqlite3BtreeKeySize(BtCursor*, i64 *pSize);
+int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);
+sqlite3 *sqlite3BtreeCursorDb(const BtCursor*);
+const void *sqlite3BtreeKeyFetch(BtCursor*, int *pAmt);
+const void *sqlite3BtreeDataFetch(BtCursor*, int *pAmt);
+int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
+int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);
+
+char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
+struct Pager *sqlite3BtreePager(Btree*);
+
+int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
+void sqlite3BtreeCacheOverflow(BtCursor *);
+
+#ifdef SQLITE_TEST
+int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
+void sqlite3BtreeCursorList(Btree*);
+#endif
+
+/*
+** If we are not using shared cache, then there is no need to
+** use mutexes to access the BtShared structures.  So make the
+** Enter and Leave procedures no-ops.
+*/
+#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE
+  void sqlite3BtreeEnter(Btree*);
+  void sqlite3BtreeLeave(Btree*);
+#ifndef NDEBUG
+  /* This routine is used inside assert() statements only. */
+  int sqlite3BtreeHoldsMutex(Btree*);
+#endif
+  void sqlite3BtreeEnterCursor(BtCursor*);
+  void sqlite3BtreeLeaveCursor(BtCursor*);
+  void sqlite3BtreeEnterAll(sqlite3*);
+  void sqlite3BtreeLeaveAll(sqlite3*);
+#ifndef NDEBUG
+  /* This routine is used inside assert() statements only. */
+  int sqlite3BtreeHoldsAllMutexes(sqlite3*);
+#endif
+  void sqlite3BtreeMutexArrayEnter(BtreeMutexArray*);
+  void sqlite3BtreeMutexArrayLeave(BtreeMutexArray*);
+  void sqlite3BtreeMutexArrayInsert(BtreeMutexArray*, Btree*);
+#else
+# define sqlite3BtreeEnter(X)
+# define sqlite3BtreeLeave(X)
+#ifndef NDEBUG
+  /* This routine is used inside assert() statements only. */
+# define sqlite3BtreeHoldsMutex(X) 1
+#endif
+# define sqlite3BtreeEnterCursor(X)
+# define sqlite3BtreeLeaveCursor(X)
+# define sqlite3BtreeEnterAll(X)
+# define sqlite3BtreeLeaveAll(X)
+#ifndef NDEBUG
+  /* This routine is used inside assert() statements only. */
+# define sqlite3BtreeHoldsAllMutexes(X) 1
+#endif
+# define sqlite3BtreeMutexArrayEnter(X)
+# define sqlite3BtreeMutexArrayLeave(X)
+# define sqlite3BtreeMutexArrayInsert(X,Y)
+#endif
+
+
+#endif /* _BTREE_H_ */
diff --git a/third_party/sqlite/src/btreeInt.h b/third_party/sqlite/src/btreeInt.h
new file mode 100755
index 0000000..663a41e
--- /dev/null
+++ b/third_party/sqlite/src/btreeInt.h
@@ -0,0 +1,627 @@
+/*
+** 2004 April 6
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** $Id: btreeInt.h,v 1.30 2008/08/01 20:10:08 drh Exp $
+**
+** This file implements a external (disk-based) database using BTrees.
+** For a detailed discussion of BTrees, refer to
+**
+**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
+**     "Sorting And Searching", pages 473-480. Addison-Wesley
+**     Publishing Company, Reading, Massachusetts.
+**
+** The basic idea is that each page of the file contains N database
+** entries and N+1 pointers to subpages.
+**
+**   ----------------------------------------------------------------
+**   |  Ptr(0) | Key(0) | Ptr(1) | Key(1) | ... | Key(N-1) | Ptr(N) |
+**   ----------------------------------------------------------------
+**
+** All of the keys on the page that Ptr(0) points to have values less
+** than Key(0).  All of the keys on page Ptr(1) and its subpages have
+** values greater than Key(0) and less than Key(1).  All of the keys
+** on Ptr(N) and its subpages have values greater than Key(N-1).  And
+** so forth.
+**
+** Finding a particular key requires reading O(log(M)) pages from the 
+** disk where M is the number of entries in the tree.
+**
+** In this implementation, a single file can hold one or more separate 
+** BTrees.  Each BTree is identified by the index of its root page.  The
+** key and data for any entry are combined to form the "payload".  A
+** fixed amount of payload can be carried directly on the database
+** page.  If the payload is larger than the preset amount then surplus
+** bytes are stored on overflow pages.  The payload for an entry
+** and the preceding pointer are combined to form a "Cell".  Each 
+** page has a small header which contains the Ptr(N) pointer and other
+** information such as the size of key and data.
+**
+** FORMAT DETAILS
+**
+** The file is divided into pages.  The first page is called page 1,
+** the second is page 2, and so forth.  A page number of zero indicates
+** "no such page".  The page size can be anything between 512 and 65536.
+** Each page can be either a btree page, a freelist page or an overflow
+** page.
+**
+** The first page is always a btree page.  The first 100 bytes of the first
+** page contain a special header (the "file header") that describes the file.
+** The format of the file header is as follows:
+**
+**   OFFSET   SIZE    DESCRIPTION
+**      0      16     Header string: "SQLite format 3\000"
+**     16       2     Page size in bytes.  
+**     18       1     File format write version
+**     19       1     File format read version
+**     20       1     Bytes of unused space at the end of each page
+**     21       1     Max embedded payload fraction
+**     22       1     Min embedded payload fraction
+**     23       1     Min leaf payload fraction
+**     24       4     File change counter
+**     28       4     Reserved for future use
+**     32       4     First freelist page
+**     36       4     Number of freelist pages in the file
+**     40      60     15 4-byte meta values passed to higher layers
+**
+** All of the integer values are big-endian (most significant byte first).
+**
+** The file change counter is incremented when the database is changed
+** This counter allows other processes to know when the file has changed
+** and thus when they need to flush their cache.
+**
+** The max embedded payload fraction is the amount of the total usable
+** space in a page that can be consumed by a single cell for standard
+** B-tree (non-LEAFDATA) tables.  A value of 255 means 100%.  The default
+** is to limit the maximum cell size so that at least 4 cells will fit
+** on one page.  Thus the default max embedded payload fraction is 64.
+**
+** If the payload for a cell is larger than the max payload, then extra
+** payload is spilled to overflow pages.  Once an overflow page is allocated,
+** as many bytes as possible are moved into the overflow pages without letting
+** the cell size drop below the min embedded payload fraction.
+**
+** The min leaf payload fraction is like the min embedded payload fraction
+** except that it applies to leaf nodes in a LEAFDATA tree.  The maximum
+** payload fraction for a LEAFDATA tree is always 100% (or 255) and it
+** not specified in the header.
+**
+** Each btree pages is divided into three sections:  The header, the
+** cell pointer array, and the cell content area.  Page 1 also has a 100-byte
+** file header that occurs before the page header.
+**
+**      |----------------|
+**      | file header    |   100 bytes.  Page 1 only.
+**      |----------------|
+**      | page header    |   8 bytes for leaves.  12 bytes for interior nodes
+**      |----------------|
+**      | cell pointer   |   |  2 bytes per cell.  Sorted order.
+**      | array          |   |  Grows downward
+**      |                |   v
+**      |----------------|
+**      | unallocated    |
+**      | space          |
+**      |----------------|   ^  Grows upwards
+**      | cell content   |   |  Arbitrary order interspersed with freeblocks.
+**      | area           |   |  and free space fragments.
+**      |----------------|
+**
+** The page headers looks like this:
+**
+**   OFFSET   SIZE     DESCRIPTION
+**      0       1      Flags. 1: intkey, 2: zerodata, 4: leafdata, 8: leaf
+**      1       2      byte offset to the first freeblock
+**      3       2      number of cells on this page
+**      5       2      first byte of the cell content area
+**      7       1      number of fragmented free bytes
+**      8       4      Right child (the Ptr(N) value).  Omitted on leaves.
+**
+** The flags define the format of this btree page.  The leaf flag means that
+** this page has no children.  The zerodata flag means that this page carries
+** only keys and no data.  The intkey flag means that the key is a integer
+** which is stored in the key size entry of the cell header rather than in
+** the payload area.
+**
+** The cell pointer array begins on the first byte after the page header.
+** The cell pointer array contains zero or more 2-byte numbers which are
+** offsets from the beginning of the page to the cell content in the cell
+** content area.  The cell pointers occur in sorted order.  The system strives
+** to keep free space after the last cell pointer so that new cells can
+** be easily added without having to defragment the page.
+**
+** Cell content is stored at the very end of the page and grows toward the
+** beginning of the page.
+**
+** Unused space within the cell content area is collected into a linked list of
+** freeblocks.  Each freeblock is at least 4 bytes in size.  The byte offset
+** to the first freeblock is given in the header.  Freeblocks occur in
+** increasing order.  Because a freeblock must be at least 4 bytes in size,
+** any group of 3 or fewer unused bytes in the cell content area cannot
+** exist on the freeblock chain.  A group of 3 or fewer free bytes is called
+** a fragment.  The total number of bytes in all fragments is recorded.
+** in the page header at offset 7.
+**
+**    SIZE    DESCRIPTION
+**      2     Byte offset of the next freeblock
+**      2     Bytes in this freeblock
+**
+** Cells are of variable length.  Cells are stored in the cell content area at
+** the end of the page.  Pointers to the cells are in the cell pointer array
+** that immediately follows the page header.  Cells is not necessarily
+** contiguous or in order, but cell pointers are contiguous and in order.
+**
+** Cell content makes use of variable length integers.  A variable
+** length integer is 1 to 9 bytes where the lower 7 bits of each 
+** byte are used.  The integer consists of all bytes that have bit 8 set and
+** the first byte with bit 8 clear.  The most significant byte of the integer
+** appears first.  A variable-length integer may not be more than 9 bytes long.
+** As a special case, all 8 bytes of the 9th byte are used as data.  This
+** allows a 64-bit integer to be encoded in 9 bytes.
+**
+**    0x00                      becomes  0x00000000
+**    0x7f                      becomes  0x0000007f
+**    0x81 0x00                 becomes  0x00000080
+**    0x82 0x00                 becomes  0x00000100
+**    0x80 0x7f                 becomes  0x0000007f
+**    0x8a 0x91 0xd1 0xac 0x78  becomes  0x12345678
+**    0x81 0x81 0x81 0x81 0x01  becomes  0x10204081
+**
+** Variable length integers are used for rowids and to hold the number of
+** bytes of key and data in a btree cell.
+**
+** The content of a cell looks like this:
+**
+**    SIZE    DESCRIPTION
+**      4     Page number of the left child. Omitted if leaf flag is set.
+**     var    Number of bytes of data. Omitted if the zerodata flag is set.
+**     var    Number of bytes of key. Or the key itself if intkey flag is set.
+**      *     Payload
+**      4     First page of the overflow chain.  Omitted if no overflow
+**
+** Overflow pages form a linked list.  Each page except the last is completely
+** filled with data (pagesize - 4 bytes).  The last page can have as little
+** as 1 byte of data.
+**
+**    SIZE    DESCRIPTION
+**      4     Page number of next overflow page
+**      *     Data
+**
+** Freelist pages come in two subtypes: trunk pages and leaf pages.  The
+** file header points to the first in a linked list of trunk page.  Each trunk
+** page points to multiple leaf pages.  The content of a leaf page is
+** unspecified.  A trunk page looks like this:
+**
+**    SIZE    DESCRIPTION
+**      4     Page number of next trunk page
+**      4     Number of leaf pointers on this page
+**      *     zero or more pages numbers of leaves
+*/
+#include "sqliteInt.h"
+#include "pager.h"
+#include "btree.h"
+#include "os.h"
+#include <assert.h>
+
+/* Round up a number to the next larger multiple of 8.  This is used
+** to force 8-byte alignment on 64-bit architectures.
+*/
+#define ROUND8(x)   ((x+7)&~7)
+
+
+/* The following value is the maximum cell size assuming a maximum page
+** size give above.
+*/
+#define MX_CELL_SIZE(pBt)  (pBt->pageSize-8)
+
+/* The maximum number of cells on a single page of the database.  This
+** assumes a minimum cell size of 6 bytes  (4 bytes for the cell itself
+** plus 2 bytes for the index to the cell in the page header).  Such
+** small cells will be rare, but they are possible.
+*/
+#define MX_CELL(pBt) ((pBt->pageSize-8)/6)
+
+/* Forward declarations */
+typedef struct MemPage MemPage;
+typedef struct BtLock BtLock;
+
+/*
+** This is a magic string that appears at the beginning of every
+** SQLite database in order to identify the file as a real database.
+**
+** You can change this value at compile-time by specifying a
+** -DSQLITE_FILE_HEADER="..." on the compiler command-line.  The
+** header must be exactly 16 bytes including the zero-terminator so
+** the string itself should be 15 characters long.  If you change
+** the header, then your custom library will not be able to read 
+** databases generated by the standard tools and the standard tools
+** will not be able to read databases created by your custom library.
+*/
+#ifndef SQLITE_FILE_HEADER /* 123456789 123456 */
+#  define SQLITE_FILE_HEADER "SQLite format 3"
+#endif
+
+/*
+** Page type flags.  An ORed combination of these flags appear as the
+** first byte of on-disk image of every BTree page.
+*/
+#define PTF_INTKEY    0x01
+#define PTF_ZERODATA  0x02
+#define PTF_LEAFDATA  0x04
+#define PTF_LEAF      0x08
+
+/*
+** As each page of the file is loaded into memory, an instance of the following
+** structure is appended and initialized to zero.  This structure stores
+** information about the page that is decoded from the raw file page.
+**
+** The pParent field points back to the parent page.  This allows us to
+** walk up the BTree from any leaf to the root.  Care must be taken to
+** unref() the parent page pointer when this page is no longer referenced.
+** The pageDestructor() routine handles that chore.
+**
+** Access to all fields of this structure is controlled by the mutex
+** stored in MemPage.pBt->mutex.
+*/
+struct MemPage {
+  u8 isInit;           /* True if previously initialized. MUST BE FIRST! */
+  u8 idxShift;         /* True if Cell indices have changed */
+  u8 nOverflow;        /* Number of overflow cell bodies in aCell[] */
+  u8 intKey;           /* True if intkey flag is set */
+  u8 leaf;             /* True if leaf flag is set */
+  u8 hasData;          /* True if this page stores data */
+  u8 hdrOffset;        /* 100 for page 1.  0 otherwise */
+  u8 childPtrSize;     /* 0 if leaf==1.  4 if leaf==0 */
+  u16 maxLocal;        /* Copy of BtShared.maxLocal or BtShared.maxLeaf */
+  u16 minLocal;        /* Copy of BtShared.minLocal or BtShared.minLeaf */
+  u16 cellOffset;      /* Index in aData of first cell pointer */
+  u16 idxParent;       /* Index in parent of this node */
+  u16 nFree;           /* Number of free bytes on the page */
+  u16 nCell;           /* Number of cells on this page, local and ovfl */
+  u16 maskPage;        /* Mask for page offset */
+  struct _OvflCell {   /* Cells that will not fit on aData[] */
+    u8 *pCell;          /* Pointers to the body of the overflow cell */
+    u16 idx;            /* Insert this cell before idx-th non-overflow cell */
+  } aOvfl[5];
+  BtShared *pBt;       /* Pointer to BtShared that this page is part of */
+  u8 *aData;           /* Pointer to disk image of the page data */
+  DbPage *pDbPage;     /* Pager page handle */
+  Pgno pgno;           /* Page number for this page */
+  MemPage *pParent;    /* The parent of this page.  NULL for root */
+};
+
+/*
+** The in-memory image of a disk page has the auxiliary information appended
+** to the end.  EXTRA_SIZE is the number of bytes of space needed to hold
+** that extra information.
+*/
+#define EXTRA_SIZE sizeof(MemPage)
+
+/* A Btree handle
+**
+** A database connection contains a pointer to an instance of
+** this object for every database file that it has open.  This structure
+** is opaque to the database connection.  The database connection cannot
+** see the internals of this structure and only deals with pointers to
+** this structure.
+**
+** For some database files, the same underlying database cache might be 
+** shared between multiple connections.  In that case, each contection
+** has it own pointer to this object.  But each instance of this object
+** points to the same BtShared object.  The database cache and the
+** schema associated with the database file are all contained within
+** the BtShared object.
+**
+** All fields in this structure are accessed under sqlite3.mutex.
+** The pBt pointer itself may not be changed while there exists cursors 
+** in the referenced BtShared that point back to this Btree since those
+** cursors have to do go through this Btree to find their BtShared and
+** they often do so without holding sqlite3.mutex.
+*/
+struct Btree {
+  sqlite3 *db;       /* The database connection holding this btree */
+  BtShared *pBt;     /* Sharable content of this btree */
+  u8 inTrans;        /* TRANS_NONE, TRANS_READ or TRANS_WRITE */
+  u8 sharable;       /* True if we can share pBt with another db */
+  u8 locked;         /* True if db currently has pBt locked */
+  int wantToLock;    /* Number of nested calls to sqlite3BtreeEnter() */
+  Btree *pNext;      /* List of other sharable Btrees from the same db */
+  Btree *pPrev;      /* Back pointer of the same list */
+};
+
+/*
+** Btree.inTrans may take one of the following values.
+**
+** If the shared-data extension is enabled, there may be multiple users
+** of the Btree structure. At most one of these may open a write transaction,
+** but any number may have active read transactions.
+*/
+#define TRANS_NONE  0
+#define TRANS_READ  1
+#define TRANS_WRITE 2
+
+/*
+** An instance of this object represents a single database file.
+** 
+** A single database file can be in use as the same time by two
+** or more database connections.  When two or more connections are
+** sharing the same database file, each connection has it own
+** private Btree object for the file and each of those Btrees points
+** to this one BtShared object.  BtShared.nRef is the number of
+** connections currently sharing this database file.
+**
+** Fields in this structure are accessed under the BtShared.mutex
+** mutex, except for nRef and pNext which are accessed under the
+** global SQLITE_MUTEX_STATIC_MASTER mutex.  The pPager field
+** may not be modified once it is initially set as long as nRef>0.
+** The pSchema field may be set once under BtShared.mutex and
+** thereafter is unchanged as long as nRef>0.
+*/
+struct BtShared {
+  Pager *pPager;        /* The page cache */
+  sqlite3 *db;          /* Database connection currently using this Btree */
+  BtCursor *pCursor;    /* A list of all open cursors */
+  MemPage *pPage1;      /* First page of the database */
+  u8 inStmt;            /* True if we are in a statement subtransaction */
+  u8 readOnly;          /* True if the underlying file is readonly */
+  u8 pageSizeFixed;     /* True if the page size can no longer be changed */
+#ifndef SQLITE_OMIT_AUTOVACUUM
+  u8 autoVacuum;        /* True if auto-vacuum is enabled */
+  u8 incrVacuum;        /* True if incr-vacuum is enabled */
+  Pgno nTrunc;          /* Non-zero if the db will be truncated (incr vacuum) */
+#endif
+  u16 pageSize;         /* Total number of bytes on a page */
+  u16 usableSize;       /* Number of usable bytes on each page */
+  int maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
+  int minLocal;         /* Minimum local payload in non-LEAFDATA tables */
+  int maxLeaf;          /* Maximum local payload in a LEAFDATA table */
+  int minLeaf;          /* Minimum local payload in a LEAFDATA table */
+  u8 inTransaction;     /* Transaction state */
+  int nTransaction;     /* Number of open transactions (read + write) */
+  void *pSchema;        /* Pointer to space allocated by sqlite3BtreeSchema() */
+  void (*xFreeSchema)(void*);  /* Destructor for BtShared.pSchema */
+  sqlite3_mutex *mutex; /* Non-recursive mutex required to access this struct */
+  BusyHandler busyHdr;  /* The busy handler for this btree */
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  int nRef;             /* Number of references to this structure */
+  BtShared *pNext;      /* Next on a list of sharable BtShared structs */
+  BtLock *pLock;        /* List of locks held on this shared-btree struct */
+  Btree *pExclusive;    /* Btree with an EXCLUSIVE lock on the whole db */
+#endif
+  u8 *pTmpSpace;        /* BtShared.pageSize bytes of space for tmp use */
+};
+
+/*
+** An instance of the following structure is used to hold information
+** about a cell.  The parseCellPtr() function fills in this structure
+** based on information extract from the raw disk page.
+*/
+typedef struct CellInfo CellInfo;
+struct CellInfo {
+  u8 *pCell;     /* Pointer to the start of cell content */
+  i64 nKey;      /* The key for INTKEY tables, or number of bytes in key */
+  u32 nData;     /* Number of bytes of data */
+  u32 nPayload;  /* Total amount of payload */
+  u16 nHeader;   /* Size of the cell content header in bytes */
+  u16 nLocal;    /* Amount of payload held locally */
+  u16 iOverflow; /* Offset to overflow page number.  Zero if no overflow */
+  u16 nSize;     /* Size of the cell content on the main b-tree page */
+};
+
+/*
+** A cursor is a pointer to a particular entry within a particular
+** b-tree within a database file.
+**
+** The entry is identified by its MemPage and the index in
+** MemPage.aCell[] of the entry.
+**
+** When a single database file can shared by two more database connections,
+** but cursors cannot be shared.  Each cursor is associated with a
+** particular database connection identified BtCursor.pBtree.db.
+**
+** Fields in this structure are accessed under the BtShared.mutex
+** found at self->pBt->mutex. 
+*/
+struct BtCursor {
+  Btree *pBtree;            /* The Btree to which this cursor belongs */
+  BtShared *pBt;            /* The BtShared this cursor points to */
+  BtCursor *pNext, *pPrev;  /* Forms a linked list of all cursors */
+  struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */
+  Pgno pgnoRoot;            /* The root page of this tree */
+  MemPage *pPage;           /* Page that contains the entry */
+  int idx;                  /* Index of the entry in pPage->aCell[] */
+  CellInfo info;            /* A parse of the cell we are pointing at */
+  u8 wrFlag;                /* True if writable */
+  u8 atLast;                /* Cursor pointing to the last entry */
+  u8 validNKey;             /* True if info.nKey is valid */
+  u8 eState;                /* One of the CURSOR_XXX constants (see below) */
+  void *pKey;      /* Saved key that was cursor's last known position */
+  i64 nKey;        /* Size of pKey, or last integer key */
+  int skip;        /* (skip<0) -> Prev() is a no-op. (skip>0) -> Next() is */
+#ifndef SQLITE_OMIT_INCRBLOB
+  u8 isIncrblobHandle;      /* True if this cursor is an incr. io handle */
+  Pgno *aOverflow;          /* Cache of overflow page locations */
+#endif
+};
+
+/*
+** Potential values for BtCursor.eState.
+**
+** CURSOR_VALID:
+**   Cursor points to a valid entry. getPayload() etc. may be called.
+**
+** CURSOR_INVALID:
+**   Cursor does not point to a valid entry. This can happen (for example) 
+**   because the table is empty or because BtreeCursorFirst() has not been
+**   called.
+**
+** CURSOR_REQUIRESEEK:
+**   The table that this cursor was opened on still exists, but has been 
+**   modified since the cursor was last used. The cursor position is saved
+**   in variables BtCursor.pKey and BtCursor.nKey. When a cursor is in 
+**   this state, restoreCursorPosition() can be called to attempt to
+**   seek the cursor to the saved position.
+**
+** CURSOR_FAULT:
+**   A unrecoverable error (an I/O error or a malloc failure) has occurred
+**   on a different connection that shares the BtShared cache with this
+**   cursor.  The error has left the cache in an inconsistent state.
+**   Do nothing else with this cursor.  Any attempt to use the cursor
+**   should return the error code stored in BtCursor.skip
+*/
+#define CURSOR_INVALID           0
+#define CURSOR_VALID             1
+#define CURSOR_REQUIRESEEK       2
+#define CURSOR_FAULT             3
+
+/* The database page the PENDING_BYTE occupies. This page is never used.
+** TODO: This macro is very similary to PAGER_MJ_PGNO() in pager.c. They
+** should possibly be consolidated (presumably in pager.h).
+**
+** If disk I/O is omitted (meaning that the database is stored purely
+** in memory) then there is no pending byte.
+*/
+#ifdef SQLITE_OMIT_DISKIO
+# define PENDING_BYTE_PAGE(pBt)  0x7fffffff
+#else
+# define PENDING_BYTE_PAGE(pBt) ((PENDING_BYTE/(pBt)->pageSize)+1)
+#endif
+
+/*
+** A linked list of the following structures is stored at BtShared.pLock.
+** Locks are added (or upgraded from READ_LOCK to WRITE_LOCK) when a cursor 
+** is opened on the table with root page BtShared.iTable. Locks are removed
+** from this list when a transaction is committed or rolled back, or when
+** a btree handle is closed.
+*/
+struct BtLock {
+  Btree *pBtree;        /* Btree handle holding this lock */
+  Pgno iTable;          /* Root page of table */
+  u8 eLock;             /* READ_LOCK or WRITE_LOCK */
+  BtLock *pNext;        /* Next in BtShared.pLock list */
+};
+
+/* Candidate values for BtLock.eLock */
+#define READ_LOCK     1
+#define WRITE_LOCK    2
+
+/*
+** These macros define the location of the pointer-map entry for a 
+** database page. The first argument to each is the number of usable
+** bytes on each page of the database (often 1024). The second is the
+** page number to look up in the pointer map.
+**
+** PTRMAP_PAGENO returns the database page number of the pointer-map
+** page that stores the required pointer. PTRMAP_PTROFFSET returns
+** the offset of the requested map entry.
+**
+** If the pgno argument passed to PTRMAP_PAGENO is a pointer-map page,
+** then pgno is returned. So (pgno==PTRMAP_PAGENO(pgsz, pgno)) can be
+** used to test if pgno is a pointer-map page. PTRMAP_ISPAGE implements
+** this test.
+*/
+#define PTRMAP_PAGENO(pBt, pgno) ptrmapPageno(pBt, pgno)
+#define PTRMAP_PTROFFSET(pgptrmap, pgno) (5*(pgno-pgptrmap-1))
+#define PTRMAP_ISPAGE(pBt, pgno) (PTRMAP_PAGENO((pBt),(pgno))==(pgno))
+
+/*
+** The pointer map is a lookup table that identifies the parent page for
+** each child page in the database file.  The parent page is the page that
+** contains a pointer to the child.  Every page in the database contains
+** 0 or 1 parent pages.  (In this context 'database page' refers
+** to any page that is not part of the pointer map itself.)  Each pointer map
+** entry consists of a single byte 'type' and a 4 byte parent page number.
+** The PTRMAP_XXX identifiers below are the valid types.
+**
+** The purpose of the pointer map is to facility moving pages from one
+** position in the file to another as part of autovacuum.  When a page
+** is moved, the pointer in its parent must be updated to point to the
+** new location.  The pointer map is used to locate the parent page quickly.
+**
+** PTRMAP_ROOTPAGE: The database page is a root-page. The page-number is not
+**                  used in this case.
+**
+** PTRMAP_FREEPAGE: The database page is an unused (free) page. The page-number 
+**                  is not used in this case.
+**
+** PTRMAP_OVERFLOW1: The database page is the first page in a list of 
+**                   overflow pages. The page number identifies the page that
+**                   contains the cell with a pointer to this overflow page.
+**
+** PTRMAP_OVERFLOW2: The database page is the second or later page in a list of
+**                   overflow pages. The page-number identifies the previous
+**                   page in the overflow page list.
+**
+** PTRMAP_BTREE: The database page is a non-root btree page. The page number
+**               identifies the parent page in the btree.
+*/
+#define PTRMAP_ROOTPAGE 1
+#define PTRMAP_FREEPAGE 2
+#define PTRMAP_OVERFLOW1 3
+#define PTRMAP_OVERFLOW2 4
+#define PTRMAP_BTREE 5
+
+/* A bunch of assert() statements to check the transaction state variables
+** of handle p (type Btree*) are internally consistent.
+*/
+#define btreeIntegrity(p) \
+  assert( p->pBt->inTransaction!=TRANS_NONE || p->pBt->nTransaction==0 ); \
+  assert( p->pBt->inTransaction>=p->inTrans ); 
+
+
+/*
+** The ISAUTOVACUUM macro is used within balance_nonroot() to determine
+** if the database supports auto-vacuum or not. Because it is used
+** within an expression that is an argument to another macro 
+** (sqliteMallocRaw), it is not possible to use conditional compilation.
+** So, this macro is defined instead.
+*/
+#ifndef SQLITE_OMIT_AUTOVACUUM
+#define ISAUTOVACUUM (pBt->autoVacuum)
+#else
+#define ISAUTOVACUUM 0
+#endif
+
+
+/*
+** This structure is passed around through all the sanity checking routines
+** in order to keep track of some global state information.
+*/
+typedef struct IntegrityCk IntegrityCk;
+struct IntegrityCk {
+  BtShared *pBt;    /* The tree being checked out */
+  Pager *pPager;    /* The associated pager.  Also accessible by pBt->pPager */
+  int nPage;        /* Number of pages in the database */
+  int *anRef;       /* Number of times each page is referenced */
+  int mxErr;        /* Stop accumulating errors when this reaches zero */
+  int nErr;         /* Number of messages written to zErrMsg so far */
+  int mallocFailed; /* A memory allocation error has occurred */
+  StrAccum errMsg;  /* Accumulate the error message text here */
+};
+
+/*
+** Read or write a two- and four-byte big-endian integer values.
+*/
+#define get2byte(x)   ((x)[0]<<8 | (x)[1])
+#define put2byte(p,v) ((p)[0] = (v)>>8, (p)[1] = (v))
+#define get4byte sqlite3Get4byte
+#define put4byte sqlite3Put4byte
+
+/*
+** Internal routines that should be accessed by the btree layer only.
+*/
+int sqlite3BtreeGetPage(BtShared*, Pgno, MemPage**, int);
+int sqlite3BtreeInitPage(MemPage *pPage, MemPage *pParent);
+void sqlite3BtreeParseCellPtr(MemPage*, u8*, CellInfo*);
+void sqlite3BtreeParseCell(MemPage*, int, CellInfo*);
+int sqlite3BtreeRestoreCursorPosition(BtCursor *pCur);
+void sqlite3BtreeGetTempCursor(BtCursor *pCur, BtCursor *pTempCur);
+void sqlite3BtreeReleaseTempCursor(BtCursor *pCur);
+int sqlite3BtreeIsRootPage(MemPage *pPage);
+void sqlite3BtreeMoveToParent(BtCursor *pCur);
diff --git a/third_party/sqlite/src/build.c b/third_party/sqlite/src/build.c
new file mode 100755
index 0000000..a20ee69
--- /dev/null
+++ b/third_party/sqlite/src/build.c
@@ -0,0 +1,3525 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains C code routines that are called by the SQLite parser
+** when syntax rules are reduced.  The routines in this file handle the
+** following kinds of SQL syntax:
+**
+**     CREATE TABLE
+**     DROP TABLE
+**     CREATE INDEX
+**     DROP INDEX
+**     creating ID lists
+**     BEGIN TRANSACTION
+**     COMMIT
+**     ROLLBACK
+**
+** $Id: build.c,v 1.494 2008/08/06 13:47:41 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+
+#include "pager.h"
+#include "btree.h"
+
+/*
+** This routine is called when a new SQL statement is beginning to
+** be parsed.  Initialize the pParse structure as needed.
+*/
+void sqlite3BeginParse(Parse *pParse, int explainFlag){
+  pParse->explain = explainFlag;
+  pParse->nVar = 0;
+}
+
+#ifndef SQLITE_OMIT_SHARED_CACHE
+/*
+** The TableLock structure is only used by the sqlite3TableLock() and
+** codeTableLocks() functions.
+*/
+struct TableLock {
+  int iDb;             /* The database containing the table to be locked */
+  int iTab;            /* The root page of the table to be locked */
+  u8 isWriteLock;      /* True for write lock.  False for a read lock */
+  const char *zName;   /* Name of the table */
+};
+
+/*
+** Record the fact that we want to lock a table at run-time.  
+**
+** The table to be locked has root page iTab and is found in database iDb.
+** A read or a write lock can be taken depending on isWritelock.
+**
+** This routine just records the fact that the lock is desired.  The
+** code to make the lock occur is generated by a later call to
+** codeTableLocks() which occurs during sqlite3FinishCoding().
+*/
+void sqlite3TableLock(
+  Parse *pParse,     /* Parsing context */
+  int iDb,           /* Index of the database containing the table to lock */
+  int iTab,          /* Root page number of the table to be locked */
+  u8 isWriteLock,    /* True for a write lock */
+  const char *zName  /* Name of the table to be locked */
+){
+  int i;
+  int nBytes;
+  TableLock *p;
+
+  if( iDb<0 ){
+    return;
+  }
+
+  for(i=0; i<pParse->nTableLock; i++){
+    p = &pParse->aTableLock[i];
+    if( p->iDb==iDb && p->iTab==iTab ){
+      p->isWriteLock = (p->isWriteLock || isWriteLock);
+      return;
+    }
+  }
+
+  nBytes = sizeof(TableLock) * (pParse->nTableLock+1);
+  pParse->aTableLock = 
+      sqlite3DbReallocOrFree(pParse->db, pParse->aTableLock, nBytes);
+  if( pParse->aTableLock ){
+    p = &pParse->aTableLock[pParse->nTableLock++];
+    p->iDb = iDb;
+    p->iTab = iTab;
+    p->isWriteLock = isWriteLock;
+    p->zName = zName;
+  }else{
+    pParse->nTableLock = 0;
+    pParse->db->mallocFailed = 1;
+  }
+}
+
+/*
+** Code an OP_TableLock instruction for each table locked by the
+** statement (configured by calls to sqlite3TableLock()).
+*/
+static void codeTableLocks(Parse *pParse){
+  int i;
+  Vdbe *pVdbe; 
+
+  if( 0==(pVdbe = sqlite3GetVdbe(pParse)) ){
+    return;
+  }
+
+  for(i=0; i<pParse->nTableLock; i++){
+    TableLock *p = &pParse->aTableLock[i];
+    int p1 = p->iDb;
+    sqlite3VdbeAddOp4(pVdbe, OP_TableLock, p1, p->iTab, p->isWriteLock,
+                      p->zName, P4_STATIC);
+  }
+}
+#else
+  #define codeTableLocks(x)
+#endif
+
+/*
+** This routine is called after a single SQL statement has been
+** parsed and a VDBE program to execute that statement has been
+** prepared.  This routine puts the finishing touches on the
+** VDBE program and resets the pParse structure for the next
+** parse.
+**
+** Note that if an error occurred, it might be the case that
+** no VDBE code was generated.
+*/
+void sqlite3FinishCoding(Parse *pParse){
+  sqlite3 *db;
+  Vdbe *v;
+
+  db = pParse->db;
+  if( db->mallocFailed ) return;
+  if( pParse->nested ) return;
+  if( pParse->nErr ) return;
+
+  /* Begin by generating some termination code at the end of the
+  ** vdbe program
+  */
+  v = sqlite3GetVdbe(pParse);
+  if( v ){
+    sqlite3VdbeAddOp0(v, OP_Halt);
+
+    /* The cookie mask contains one bit for each database file open.
+    ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are
+    ** set for each database that is used.  Generate code to start a
+    ** transaction on each used database and to verify the schema cookie
+    ** on each used database.
+    */
+    if( pParse->cookieGoto>0 ){
+      u32 mask;
+      int iDb;
+      sqlite3VdbeJumpHere(v, pParse->cookieGoto-1);
+      for(iDb=0, mask=1; iDb<db->nDb; mask<<=1, iDb++){
+        if( (mask & pParse->cookieMask)==0 ) continue;
+        sqlite3VdbeUsesBtree(v, iDb);
+        sqlite3VdbeAddOp2(v,OP_Transaction, iDb, (mask & pParse->writeMask)!=0);
+        sqlite3VdbeAddOp2(v,OP_VerifyCookie, iDb, pParse->cookieValue[iDb]);
+      }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+      {
+        int i;
+        for(i=0; i<pParse->nVtabLock; i++){
+          char *vtab = (char *)pParse->apVtabLock[i]->pVtab;
+          sqlite3VdbeAddOp4(v, OP_VBegin, 0, 0, 0, vtab, P4_VTAB);
+        }
+        pParse->nVtabLock = 0;
+      }
+#endif
+
+      /* Once all the cookies have been verified and transactions opened, 
+      ** obtain the required table-locks. This is a no-op unless the 
+      ** shared-cache feature is enabled.
+      */
+      codeTableLocks(pParse);
+      sqlite3VdbeAddOp2(v, OP_Goto, 0, pParse->cookieGoto);
+    }
+
+#ifndef SQLITE_OMIT_TRACE
+    if( !db->init.busy ){
+      /* Change the P4 argument of the first opcode (which will always be
+      ** an OP_Trace) to be the complete text of the current SQL statement.
+      */
+      VdbeOp *pOp = sqlite3VdbeGetOp(v, 0);
+      if( pOp && pOp->opcode==OP_Trace ){
+        sqlite3VdbeChangeP4(v, 0, pParse->zSql, pParse->zTail-pParse->zSql);
+      }
+    }
+#endif /* SQLITE_OMIT_TRACE */
+  }
+
+
+  /* Get the VDBE program ready for execution
+  */
+  if( v && pParse->nErr==0 && !db->mallocFailed ){
+#ifdef SQLITE_DEBUG
+    FILE *trace = (db->flags & SQLITE_VdbeTrace)!=0 ? stdout : 0;
+    sqlite3VdbeTrace(v, trace);
+#endif
+    assert( pParse->disableColCache==0 );  /* Disables and re-enables match */
+    sqlite3VdbeMakeReady(v, pParse->nVar, pParse->nMem+3,
+                         pParse->nTab+3, pParse->explain);
+    pParse->rc = SQLITE_DONE;
+    pParse->colNamesSet = 0;
+  }else if( pParse->rc==SQLITE_OK ){
+    pParse->rc = SQLITE_ERROR;
+  }
+  pParse->nTab = 0;
+  pParse->nMem = 0;
+  pParse->nSet = 0;
+  pParse->nVar = 0;
+  pParse->cookieMask = 0;
+  pParse->cookieGoto = 0;
+}
+
+/*
+** Run the parser and code generator recursively in order to generate
+** code for the SQL statement given onto the end of the pParse context
+** currently under construction.  When the parser is run recursively
+** this way, the final OP_Halt is not appended and other initialization
+** and finalization steps are omitted because those are handling by the
+** outermost parser.
+**
+** Not everything is nestable.  This facility is designed to permit
+** INSERT, UPDATE, and DELETE operations against SQLITE_MASTER.  Use
+** care if you decide to try to use this routine for some other purposes.
+*/
+void sqlite3NestedParse(Parse *pParse, const char *zFormat, ...){
+  va_list ap;
+  char *zSql;
+  char *zErrMsg = 0;
+  sqlite3 *db = pParse->db;
+# define SAVE_SZ  (sizeof(Parse) - offsetof(Parse,nVar))
+  char saveBuf[SAVE_SZ];
+
+  if( pParse->nErr ) return;
+  assert( pParse->nested<10 );  /* Nesting should only be of limited depth */
+  va_start(ap, zFormat);
+  zSql = sqlite3VMPrintf(db, zFormat, ap);
+  va_end(ap);
+  if( zSql==0 ){
+    return;   /* A malloc must have failed */
+  }
+  pParse->nested++;
+  memcpy(saveBuf, &pParse->nVar, SAVE_SZ);
+  memset(&pParse->nVar, 0, SAVE_SZ);
+  sqlite3RunParser(pParse, zSql, &zErrMsg);
+  sqlite3DbFree(db, zErrMsg);
+  sqlite3DbFree(db, zSql);
+  memcpy(&pParse->nVar, saveBuf, SAVE_SZ);
+  pParse->nested--;
+}
+
+/*
+** Locate the in-memory structure that describes a particular database
+** table given the name of that table and (optionally) the name of the
+** database containing the table.  Return NULL if not found.
+**
+** If zDatabase is 0, all databases are searched for the table and the
+** first matching table is returned.  (No checking for duplicate table
+** names is done.)  The search order is TEMP first, then MAIN, then any
+** auxiliary databases added using the ATTACH command.
+**
+** See also sqlite3LocateTable().
+*/
+Table *sqlite3FindTable(sqlite3 *db, const char *zName, const char *zDatabase){
+  Table *p = 0;
+  int i;
+  int nName;
+  assert( zName!=0 );
+  nName = sqlite3Strlen(db, zName) + 1;
+  for(i=OMIT_TEMPDB; i<db->nDb; i++){
+    int j = (i<2) ? i^1 : i;   /* Search TEMP before MAIN */
+    if( zDatabase!=0 && sqlite3StrICmp(zDatabase, db->aDb[j].zName) ) continue;
+    p = sqlite3HashFind(&db->aDb[j].pSchema->tblHash, zName, nName);
+    if( p ) break;
+  }
+  return p;
+}
+
+/*
+** Locate the in-memory structure that describes a particular database
+** table given the name of that table and (optionally) the name of the
+** database containing the table.  Return NULL if not found.  Also leave an
+** error message in pParse->zErrMsg.
+**
+** The difference between this routine and sqlite3FindTable() is that this
+** routine leaves an error message in pParse->zErrMsg where
+** sqlite3FindTable() does not.
+*/
+Table *sqlite3LocateTable(
+  Parse *pParse,         /* context in which to report errors */
+  int isView,            /* True if looking for a VIEW rather than a TABLE */
+  const char *zName,     /* Name of the table we are looking for */
+  const char *zDbase     /* Name of the database.  Might be NULL */
+){
+  Table *p;
+
+  /* Read the database schema. If an error occurs, leave an error message
+  ** and code in pParse and return NULL. */
+  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
+    return 0;
+  }
+
+  p = sqlite3FindTable(pParse->db, zName, zDbase);
+  if( p==0 ){
+    const char *zMsg = isView ? "no such view" : "no such table";
+    if( zDbase ){
+      sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
+    }else{
+      sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);
+    }
+    pParse->checkSchema = 1;
+  }
+  return p;
+}
+
+/*
+** Locate the in-memory structure that describes 
+** a particular index given the name of that index
+** and the name of the database that contains the index.
+** Return NULL if not found.
+**
+** If zDatabase is 0, all databases are searched for the
+** table and the first matching index is returned.  (No checking
+** for duplicate index names is done.)  The search order is
+** TEMP first, then MAIN, then any auxiliary databases added
+** using the ATTACH command.
+*/
+Index *sqlite3FindIndex(sqlite3 *db, const char *zName, const char *zDb){
+  Index *p = 0;
+  int i;
+  int nName = sqlite3Strlen(db, zName)+1;
+  for(i=OMIT_TEMPDB; i<db->nDb; i++){
+    int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
+    Schema *pSchema = db->aDb[j].pSchema;
+    if( zDb && sqlite3StrICmp(zDb, db->aDb[j].zName) ) continue;
+    assert( pSchema || (j==1 && !db->aDb[1].pBt) );
+    if( pSchema ){
+      p = sqlite3HashFind(&pSchema->idxHash, zName, nName);
+    }
+    if( p ) break;
+  }
+  return p;
+}
+
+/*
+** Reclaim the memory used by an index
+*/
+static void freeIndex(Index *p){
+  sqlite3 *db = p->pTable->db;
+  sqlite3DbFree(db, p->zColAff);
+  sqlite3DbFree(db, p);
+}
+
+/*
+** Remove the given index from the index hash table, and free
+** its memory structures.
+**
+** The index is removed from the database hash tables but
+** it is not unlinked from the Table that it indexes.
+** Unlinking from the Table must be done by the calling function.
+*/
+static void sqliteDeleteIndex(Index *p){
+  Index *pOld;
+  const char *zName = p->zName;
+
+  pOld = sqlite3HashInsert(&p->pSchema->idxHash, zName, strlen(zName)+1, 0);
+  assert( pOld==0 || pOld==p );
+  freeIndex(p);
+}
+
+/*
+** For the index called zIdxName which is found in the database iDb,
+** unlike that index from its Table then remove the index from
+** the index hash table and free all memory structures associated
+** with the index.
+*/
+void sqlite3UnlinkAndDeleteIndex(sqlite3 *db, int iDb, const char *zIdxName){
+  Index *pIndex;
+  int len;
+  Hash *pHash = &db->aDb[iDb].pSchema->idxHash;
+
+  len = sqlite3Strlen(db, zIdxName);
+  pIndex = sqlite3HashInsert(pHash, zIdxName, len+1, 0);
+  if( pIndex ){
+    if( pIndex->pTable->pIndex==pIndex ){
+      pIndex->pTable->pIndex = pIndex->pNext;
+    }else{
+      Index *p;
+      for(p=pIndex->pTable->pIndex; p && p->pNext!=pIndex; p=p->pNext){}
+      if( p && p->pNext==pIndex ){
+        p->pNext = pIndex->pNext;
+      }
+    }
+    freeIndex(pIndex);
+  }
+  db->flags |= SQLITE_InternChanges;
+}
+
+/*
+** Erase all schema information from the in-memory hash tables of
+** a single database.  This routine is called to reclaim memory
+** before the database closes.  It is also called during a rollback
+** if there were schema changes during the transaction or if a
+** schema-cookie mismatch occurs.
+**
+** If iDb<=0 then reset the internal schema tables for all database
+** files.  If iDb>=2 then reset the internal schema for only the
+** single file indicated.
+*/
+void sqlite3ResetInternalSchema(sqlite3 *db, int iDb){
+  int i, j;
+  assert( iDb>=0 && iDb<db->nDb );
+
+  if( iDb==0 ){
+    sqlite3BtreeEnterAll(db);
+  }
+  for(i=iDb; i<db->nDb; i++){
+    Db *pDb = &db->aDb[i];
+    if( pDb->pSchema ){
+      assert(i==1 || (pDb->pBt && sqlite3BtreeHoldsMutex(pDb->pBt)));
+      sqlite3SchemaFree(pDb->pSchema);
+    }
+    if( iDb>0 ) return;
+  }
+  assert( iDb==0 );
+  db->flags &= ~SQLITE_InternChanges;
+  sqlite3BtreeLeaveAll(db);
+
+  /* If one or more of the auxiliary database files has been closed,
+  ** then remove them from the auxiliary database list.  We take the
+  ** opportunity to do this here since we have just deleted all of the
+  ** schema hash tables and therefore do not have to make any changes
+  ** to any of those tables.
+  */
+  for(i=0; i<db->nDb; i++){
+    struct Db *pDb = &db->aDb[i];
+    if( pDb->pBt==0 ){
+      if( pDb->pAux && pDb->xFreeAux ) pDb->xFreeAux(pDb->pAux);
+      pDb->pAux = 0;
+    }
+  }
+  for(i=j=2; i<db->nDb; i++){
+    struct Db *pDb = &db->aDb[i];
+    if( pDb->pBt==0 ){
+      sqlite3DbFree(db, pDb->zName);
+      pDb->zName = 0;
+      continue;
+    }
+    if( j<i ){
+      db->aDb[j] = db->aDb[i];
+    }
+    j++;
+  }
+  memset(&db->aDb[j], 0, (db->nDb-j)*sizeof(db->aDb[j]));
+  db->nDb = j;
+  if( db->nDb<=2 && db->aDb!=db->aDbStatic ){
+    memcpy(db->aDbStatic, db->aDb, 2*sizeof(db->aDb[0]));
+    sqlite3DbFree(db, db->aDb);
+    db->aDb = db->aDbStatic;
+  }
+}
+
+/*
+** This routine is called when a commit occurs.
+*/
+void sqlite3CommitInternalChanges(sqlite3 *db){
+  db->flags &= ~SQLITE_InternChanges;
+}
+
+/*
+** Clear the column names from a table or view.
+*/
+static void sqliteResetColumnNames(Table *pTable){
+  int i;
+  Column *pCol;
+  sqlite3 *db = pTable->db;
+  assert( pTable!=0 );
+  if( (pCol = pTable->aCol)!=0 ){
+    for(i=0; i<pTable->nCol; i++, pCol++){
+      sqlite3DbFree(db, pCol->zName);
+      sqlite3ExprDelete(db, pCol->pDflt);
+      sqlite3DbFree(db, pCol->zType);
+      sqlite3DbFree(db, pCol->zColl);
+    }
+    sqlite3DbFree(db, pTable->aCol);
+  }
+  pTable->aCol = 0;
+  pTable->nCol = 0;
+}
+
+/*
+** Remove the memory data structures associated with the given
+** Table.  No changes are made to disk by this routine.
+**
+** This routine just deletes the data structure.  It does not unlink
+** the table data structure from the hash table.  Nor does it remove
+** foreign keys from the sqlite.aFKey hash table.  But it does destroy
+** memory structures of the indices and foreign keys associated with 
+** the table.
+*/
+void sqlite3DeleteTable(Table *pTable){
+  Index *pIndex, *pNext;
+  FKey *pFKey, *pNextFKey;
+  sqlite3 *db;
+
+  if( pTable==0 ) return;
+  db = pTable->db;
+
+  /* Do not delete the table until the reference count reaches zero. */
+  pTable->nRef--;
+  if( pTable->nRef>0 ){
+    return;
+  }
+  assert( pTable->nRef==0 );
+
+  /* Delete all indices associated with this table
+  */
+  for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
+    pNext = pIndex->pNext;
+    assert( pIndex->pSchema==pTable->pSchema );
+    sqliteDeleteIndex(pIndex);
+  }
+
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+  /* Delete all foreign keys associated with this table.  The keys
+  ** should have already been unlinked from the pSchema->aFKey hash table 
+  */
+  for(pFKey=pTable->pFKey; pFKey; pFKey=pNextFKey){
+    pNextFKey = pFKey->pNextFrom;
+    assert( sqlite3HashFind(&pTable->pSchema->aFKey,
+                           pFKey->zTo, strlen(pFKey->zTo)+1)!=pFKey );
+    sqlite3DbFree(db, pFKey);
+  }
+#endif
+
+  /* Delete the Table structure itself.
+  */
+  sqliteResetColumnNames(pTable);
+  sqlite3DbFree(db, pTable->zName);
+  sqlite3DbFree(db, pTable->zColAff);
+  sqlite3SelectDelete(db, pTable->pSelect);
+#ifndef SQLITE_OMIT_CHECK
+  sqlite3ExprDelete(db, pTable->pCheck);
+#endif
+  sqlite3VtabClear(pTable);
+  sqlite3DbFree(db, pTable);
+}
+
+/*
+** Unlink the given table from the hash tables and the delete the
+** table structure with all its indices and foreign keys.
+*/
+void sqlite3UnlinkAndDeleteTable(sqlite3 *db, int iDb, const char *zTabName){
+  Table *p;
+  FKey *pF1, *pF2;
+  Db *pDb;
+
+  assert( db!=0 );
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( zTabName && zTabName[0] );
+  pDb = &db->aDb[iDb];
+  p = sqlite3HashInsert(&pDb->pSchema->tblHash, zTabName, strlen(zTabName)+1,0);
+  if( p ){
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+    for(pF1=p->pFKey; pF1; pF1=pF1->pNextFrom){
+      int nTo = strlen(pF1->zTo) + 1;
+      pF2 = sqlite3HashFind(&pDb->pSchema->aFKey, pF1->zTo, nTo);
+      if( pF2==pF1 ){
+        sqlite3HashInsert(&pDb->pSchema->aFKey, pF1->zTo, nTo, pF1->pNextTo);
+      }else{
+        while( pF2 && pF2->pNextTo!=pF1 ){ pF2=pF2->pNextTo; }
+        if( pF2 ){
+          pF2->pNextTo = pF1->pNextTo;
+        }
+      }
+    }
+#endif
+    sqlite3DeleteTable(p);
+  }
+  db->flags |= SQLITE_InternChanges;
+}
+
+/*
+** Given a token, return a string that consists of the text of that
+** token with any quotations removed.  Space to hold the returned string
+** is obtained from sqliteMalloc() and must be freed by the calling
+** function.
+**
+** Tokens are often just pointers into the original SQL text and so
+** are not \000 terminated and are not persistent.  The returned string
+** is \000 terminated and is persistent.
+*/
+char *sqlite3NameFromToken(sqlite3 *db, Token *pName){
+  char *zName;
+  if( pName ){
+    zName = sqlite3DbStrNDup(db, (char*)pName->z, pName->n);
+    sqlite3Dequote(zName);
+  }else{
+    zName = 0;
+  }
+  return zName;
+}
+
+/*
+** Open the sqlite_master table stored in database number iDb for
+** writing. The table is opened using cursor 0.
+*/
+void sqlite3OpenMasterTable(Parse *p, int iDb){
+  Vdbe *v = sqlite3GetVdbe(p);
+  sqlite3TableLock(p, iDb, MASTER_ROOT, 1, SCHEMA_TABLE(iDb));
+  sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, 5);/* sqlite_master has 5 columns */
+  sqlite3VdbeAddOp3(v, OP_OpenWrite, 0, MASTER_ROOT, iDb);
+}
+
+/*
+** The token *pName contains the name of a database (either "main" or
+** "temp" or the name of an attached db). This routine returns the
+** index of the named database in db->aDb[], or -1 if the named db 
+** does not exist.
+*/
+int sqlite3FindDb(sqlite3 *db, Token *pName){
+  int i = -1;    /* Database number */
+  int n;         /* Number of characters in the name */
+  Db *pDb;       /* A database whose name space is being searched */
+  char *zName;   /* Name we are searching for */
+
+  zName = sqlite3NameFromToken(db, pName);
+  if( zName ){
+    n = strlen(zName);
+    for(i=(db->nDb-1), pDb=&db->aDb[i]; i>=0; i--, pDb--){
+      if( (!OMIT_TEMPDB || i!=1 ) && n==strlen(pDb->zName) && 
+          0==sqlite3StrICmp(pDb->zName, zName) ){
+        break;
+      }
+    }
+    sqlite3DbFree(db, zName);
+  }
+  return i;
+}
+
+/* The table or view or trigger name is passed to this routine via tokens
+** pName1 and pName2. If the table name was fully qualified, for example:
+**
+** CREATE TABLE xxx.yyy (...);
+** 
+** Then pName1 is set to "xxx" and pName2 "yyy". On the other hand if
+** the table name is not fully qualified, i.e.:
+**
+** CREATE TABLE yyy(...);
+**
+** Then pName1 is set to "yyy" and pName2 is "".
+**
+** This routine sets the *ppUnqual pointer to point at the token (pName1 or
+** pName2) that stores the unqualified table name.  The index of the
+** database "xxx" is returned.
+*/
+int sqlite3TwoPartName(
+  Parse *pParse,      /* Parsing and code generating context */
+  Token *pName1,      /* The "xxx" in the name "xxx.yyy" or "xxx" */
+  Token *pName2,      /* The "yyy" in the name "xxx.yyy" */
+  Token **pUnqual     /* Write the unqualified object name here */
+){
+  int iDb;                    /* Database holding the object */
+  sqlite3 *db = pParse->db;
+
+  if( pName2 && pName2->n>0 ){
+    assert( !db->init.busy );
+    *pUnqual = pName2;
+    iDb = sqlite3FindDb(db, pName1);
+    if( iDb<0 ){
+      sqlite3ErrorMsg(pParse, "unknown database %T", pName1);
+      pParse->nErr++;
+      return -1;
+    }
+  }else{
+    assert( db->init.iDb==0 || db->init.busy );
+    iDb = db->init.iDb;
+    *pUnqual = pName1;
+  }
+  return iDb;
+}
+
+/*
+** This routine is used to check if the UTF-8 string zName is a legal
+** unqualified name for a new schema object (table, index, view or
+** trigger). All names are legal except those that begin with the string
+** "sqlite_" (in upper, lower or mixed case). This portion of the namespace
+** is reserved for internal use.
+*/
+int sqlite3CheckObjectName(Parse *pParse, const char *zName){
+  if( !pParse->db->init.busy && pParse->nested==0 
+          && (pParse->db->flags & SQLITE_WriteSchema)==0
+          && 0==sqlite3StrNICmp(zName, "sqlite_", 7) ){
+    sqlite3ErrorMsg(pParse, "object name reserved for internal use: %s", zName);
+    return SQLITE_ERROR;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Begin constructing a new table representation in memory.  This is
+** the first of several action routines that get called in response
+** to a CREATE TABLE statement.  In particular, this routine is called
+** after seeing tokens "CREATE" and "TABLE" and the table name. The isTemp
+** flag is true if the table should be stored in the auxiliary database
+** file instead of in the main database file.  This is normally the case
+** when the "TEMP" or "TEMPORARY" keyword occurs in between
+** CREATE and TABLE.
+**
+** The new table record is initialized and put in pParse->pNewTable.
+** As more of the CREATE TABLE statement is parsed, additional action
+** routines will be called to add more information to this record.
+** At the end of the CREATE TABLE statement, the sqlite3EndTable() routine
+** is called to complete the construction of the new table record.
+*/
+void sqlite3StartTable(
+  Parse *pParse,   /* Parser context */
+  Token *pName1,   /* First part of the name of the table or view */
+  Token *pName2,   /* Second part of the name of the table or view */
+  int isTemp,      /* True if this is a TEMP table */
+  int isView,      /* True if this is a VIEW */
+  int isVirtual,   /* True if this is a VIRTUAL table */
+  int noErr        /* Do nothing if table already exists */
+){
+  Table *pTable;
+  char *zName = 0; /* The name of the new table */
+  sqlite3 *db = pParse->db;
+  Vdbe *v;
+  int iDb;         /* Database number to create the table in */
+  Token *pName;    /* Unqualified name of the table to create */
+
+  /* The table or view name to create is passed to this routine via tokens
+  ** pName1 and pName2. If the table name was fully qualified, for example:
+  **
+  ** CREATE TABLE xxx.yyy (...);
+  ** 
+  ** Then pName1 is set to "xxx" and pName2 "yyy". On the other hand if
+  ** the table name is not fully qualified, i.e.:
+  **
+  ** CREATE TABLE yyy(...);
+  **
+  ** Then pName1 is set to "yyy" and pName2 is "".
+  **
+  ** The call below sets the pName pointer to point at the token (pName1 or
+  ** pName2) that stores the unqualified table name. The variable iDb is
+  ** set to the index of the database that the table or view is to be
+  ** created in.
+  */
+  iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
+  if( iDb<0 ) return;
+  if( !OMIT_TEMPDB && isTemp && iDb>1 ){
+    /* If creating a temp table, the name may not be qualified */
+    sqlite3ErrorMsg(pParse, "temporary table name must be unqualified");
+    return;
+  }
+  if( !OMIT_TEMPDB && isTemp ) iDb = 1;
+
+  pParse->sNameToken = *pName;
+  zName = sqlite3NameFromToken(db, pName);
+  if( zName==0 ) return;
+  if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
+    goto begin_table_error;
+  }
+  if( db->init.iDb==1 ) isTemp = 1;
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  assert( (isTemp & 1)==isTemp );
+  {
+    int code;
+    char *zDb = db->aDb[iDb].zName;
+    if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){
+      goto begin_table_error;
+    }
+    if( isView ){
+      if( !OMIT_TEMPDB && isTemp ){
+        code = SQLITE_CREATE_TEMP_VIEW;
+      }else{
+        code = SQLITE_CREATE_VIEW;
+      }
+    }else{
+      if( !OMIT_TEMPDB && isTemp ){
+        code = SQLITE_CREATE_TEMP_TABLE;
+      }else{
+        code = SQLITE_CREATE_TABLE;
+      }
+    }
+    if( !isVirtual && sqlite3AuthCheck(pParse, code, zName, 0, zDb) ){
+      goto begin_table_error;
+    }
+  }
+#endif
+
+  /* Make sure the new table name does not collide with an existing
+  ** index or table name in the same database.  Issue an error message if
+  ** it does. The exception is if the statement being parsed was passed
+  ** to an sqlite3_declare_vtab() call. In that case only the column names
+  ** and types will be used, so there is no need to test for namespace
+  ** collisions.
+  */
+  if( !IN_DECLARE_VTAB ){
+    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
+      goto begin_table_error;
+    }
+    pTable = sqlite3FindTable(db, zName, db->aDb[iDb].zName);
+    if( pTable ){
+      if( !noErr ){
+        sqlite3ErrorMsg(pParse, "table %T already exists", pName);
+      }
+      goto begin_table_error;
+    }
+    if( sqlite3FindIndex(db, zName, 0)!=0 && (iDb==0 || !db->init.busy) ){
+      sqlite3ErrorMsg(pParse, "there is already an index named %s", zName);
+      goto begin_table_error;
+    }
+  }
+
+  pTable = sqlite3DbMallocZero(db, sizeof(Table));
+  if( pTable==0 ){
+    db->mallocFailed = 1;
+    pParse->rc = SQLITE_NOMEM;
+    pParse->nErr++;
+    goto begin_table_error;
+  }
+  pTable->zName = zName;
+  pTable->iPKey = -1;
+  pTable->pSchema = db->aDb[iDb].pSchema;
+  pTable->nRef = 1;
+  pTable->db = db;
+  if( pParse->pNewTable ) sqlite3DeleteTable(pParse->pNewTable);
+  pParse->pNewTable = pTable;
+
+  /* If this is the magic sqlite_sequence table used by autoincrement,
+  ** then record a pointer to this table in the main database structure
+  ** so that INSERT can find the table easily.
+  */
+#ifndef SQLITE_OMIT_AUTOINCREMENT
+  if( !pParse->nested && strcmp(zName, "sqlite_sequence")==0 ){
+    pTable->pSchema->pSeqTab = pTable;
+  }
+#endif
+
+  /* Begin generating the code that will insert the table record into
+  ** the SQLITE_MASTER table.  Note in particular that we must go ahead
+  ** and allocate the record number for the table entry now.  Before any
+  ** PRIMARY KEY or UNIQUE keywords are parsed.  Those keywords will cause
+  ** indices to be created and the table record must come before the 
+  ** indices.  Hence, the record number for the table must be allocated
+  ** now.
+  */
+  if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
+    int j1;
+    int fileFormat;
+    int reg1, reg2, reg3;
+    sqlite3BeginWriteOperation(pParse, 0, iDb);
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( isVirtual ){
+      sqlite3VdbeAddOp0(v, OP_VBegin);
+    }
+#endif
+
+    /* If the file format and encoding in the database have not been set, 
+    ** set them now.
+    */
+    reg1 = pParse->regRowid = ++pParse->nMem;
+    reg2 = pParse->regRoot = ++pParse->nMem;
+    reg3 = ++pParse->nMem;
+    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, reg3, 1);   /* file_format */
+    sqlite3VdbeUsesBtree(v, iDb);
+    j1 = sqlite3VdbeAddOp1(v, OP_If, reg3);
+    fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
+                  1 : SQLITE_MAX_FILE_FORMAT;
+    sqlite3VdbeAddOp2(v, OP_Integer, fileFormat, reg3);
+    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, 1, reg3);
+    sqlite3VdbeAddOp2(v, OP_Integer, ENC(db), reg3);
+    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, 4, reg3);
+    sqlite3VdbeJumpHere(v, j1);
+
+    /* This just creates a place-holder record in the sqlite_master table.
+    ** The record created does not contain anything yet.  It will be replaced
+    ** by the real entry in code generated at sqlite3EndTable().
+    **
+    ** The rowid for the new entry is left on the top of the stack.
+    ** The rowid value is needed by the code that sqlite3EndTable will
+    ** generate.
+    */
+#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
+    if( isView || isVirtual ){
+      sqlite3VdbeAddOp2(v, OP_Integer, 0, reg2);
+    }else
+#endif
+    {
+      sqlite3VdbeAddOp2(v, OP_CreateTable, iDb, reg2);
+    }
+    sqlite3OpenMasterTable(pParse, iDb);
+    sqlite3VdbeAddOp2(v, OP_NewRowid, 0, reg1);
+    sqlite3VdbeAddOp2(v, OP_Null, 0, reg3);
+    sqlite3VdbeAddOp3(v, OP_Insert, 0, reg3, reg1);
+    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
+    sqlite3VdbeAddOp0(v, OP_Close);
+  }
+
+  /* Normal (non-error) return. */
+  return;
+
+  /* If an error occurs, we jump here */
+begin_table_error:
+  sqlite3DbFree(db, zName);
+  return;
+}
+
+/*
+** This macro is used to compare two strings in a case-insensitive manner.
+** It is slightly faster than calling sqlite3StrICmp() directly, but
+** produces larger code.
+**
+** WARNING: This macro is not compatible with the strcmp() family. It
+** returns true if the two strings are equal, otherwise false.
+*/
+#define STRICMP(x, y) (\
+sqlite3UpperToLower[*(unsigned char *)(x)]==   \
+sqlite3UpperToLower[*(unsigned char *)(y)]     \
+&& sqlite3StrICmp((x)+1,(y)+1)==0 )
+
+/*
+** Add a new column to the table currently being constructed.
+**
+** The parser calls this routine once for each column declaration
+** in a CREATE TABLE statement.  sqlite3StartTable() gets called
+** first to get things going.  Then this routine is called for each
+** column.
+*/
+void sqlite3AddColumn(Parse *pParse, Token *pName){
+  Table *p;
+  int i;
+  char *z;
+  Column *pCol;
+  sqlite3 *db = pParse->db;
+  if( (p = pParse->pNewTable)==0 ) return;
+#if SQLITE_MAX_COLUMN
+  if( p->nCol+1>db->aLimit[SQLITE_LIMIT_COLUMN] ){
+    sqlite3ErrorMsg(pParse, "too many columns on %s", p->zName);
+    return;
+  }
+#endif
+  z = sqlite3NameFromToken(pParse->db, pName);
+  if( z==0 ) return;
+  for(i=0; i<p->nCol; i++){
+    if( STRICMP(z, p->aCol[i].zName) ){
+      sqlite3ErrorMsg(pParse, "duplicate column name: %s", z);
+      sqlite3DbFree(db, z);
+      return;
+    }
+  }
+  if( (p->nCol & 0x7)==0 ){
+    Column *aNew;
+    aNew = sqlite3DbRealloc(pParse->db,p->aCol,(p->nCol+8)*sizeof(p->aCol[0]));
+    if( aNew==0 ){
+      sqlite3DbFree(db, z);
+      return;
+    }
+    p->aCol = aNew;
+  }
+  pCol = &p->aCol[p->nCol];
+  memset(pCol, 0, sizeof(p->aCol[0]));
+  pCol->zName = z;
+ 
+  /* If there is no type specified, columns have the default affinity
+  ** 'NONE'. If there is a type specified, then sqlite3AddColumnType() will
+  ** be called next to set pCol->affinity correctly.
+  */
+  pCol->affinity = SQLITE_AFF_NONE;
+  p->nCol++;
+}
+
+/*
+** This routine is called by the parser while in the middle of
+** parsing a CREATE TABLE statement.  A "NOT NULL" constraint has
+** been seen on a column.  This routine sets the notNull flag on
+** the column currently under construction.
+*/
+void sqlite3AddNotNull(Parse *pParse, int onError){
+  Table *p;
+  int i;
+  if( (p = pParse->pNewTable)==0 ) return;
+  i = p->nCol-1;
+  if( i>=0 ) p->aCol[i].notNull = onError;
+}
+
+/*
+** Scan the column type name zType (length nType) and return the
+** associated affinity type.
+**
+** This routine does a case-independent search of zType for the 
+** substrings in the following table. If one of the substrings is
+** found, the corresponding affinity is returned. If zType contains
+** more than one of the substrings, entries toward the top of 
+** the table take priority. For example, if zType is 'BLOBINT', 
+** SQLITE_AFF_INTEGER is returned.
+**
+** Substring     | Affinity
+** --------------------------------
+** 'INT'         | SQLITE_AFF_INTEGER
+** 'CHAR'        | SQLITE_AFF_TEXT
+** 'CLOB'        | SQLITE_AFF_TEXT
+** 'TEXT'        | SQLITE_AFF_TEXT
+** 'BLOB'        | SQLITE_AFF_NONE
+** 'REAL'        | SQLITE_AFF_REAL
+** 'FLOA'        | SQLITE_AFF_REAL
+** 'DOUB'        | SQLITE_AFF_REAL
+**
+** If none of the substrings in the above table are found,
+** SQLITE_AFF_NUMERIC is returned.
+*/
+char sqlite3AffinityType(const Token *pType){
+  u32 h = 0;
+  char aff = SQLITE_AFF_NUMERIC;
+  const unsigned char *zIn = pType->z;
+  const unsigned char *zEnd = &pType->z[pType->n];
+
+  while( zIn!=zEnd ){
+    h = (h<<8) + sqlite3UpperToLower[*zIn];
+    zIn++;
+    if( h==(('c'<<24)+('h'<<16)+('a'<<8)+'r') ){             /* CHAR */
+      aff = SQLITE_AFF_TEXT; 
+    }else if( h==(('c'<<24)+('l'<<16)+('o'<<8)+'b') ){       /* CLOB */
+      aff = SQLITE_AFF_TEXT;
+    }else if( h==(('t'<<24)+('e'<<16)+('x'<<8)+'t') ){       /* TEXT */
+      aff = SQLITE_AFF_TEXT;
+    }else if( h==(('b'<<24)+('l'<<16)+('o'<<8)+'b')          /* BLOB */
+        && (aff==SQLITE_AFF_NUMERIC || aff==SQLITE_AFF_REAL) ){
+      aff = SQLITE_AFF_NONE;
+#ifndef SQLITE_OMIT_FLOATING_POINT
+    }else if( h==(('r'<<24)+('e'<<16)+('a'<<8)+'l')          /* REAL */
+        && aff==SQLITE_AFF_NUMERIC ){
+      aff = SQLITE_AFF_REAL;
+    }else if( h==(('f'<<24)+('l'<<16)+('o'<<8)+'a')          /* FLOA */
+        && aff==SQLITE_AFF_NUMERIC ){
+      aff = SQLITE_AFF_REAL;
+    }else if( h==(('d'<<24)+('o'<<16)+('u'<<8)+'b')          /* DOUB */
+        && aff==SQLITE_AFF_NUMERIC ){
+      aff = SQLITE_AFF_REAL;
+#endif
+    }else if( (h&0x00FFFFFF)==(('i'<<16)+('n'<<8)+'t') ){    /* INT */
+      aff = SQLITE_AFF_INTEGER;
+      break;
+    }
+  }
+
+  return aff;
+}
+
+/*
+** This routine is called by the parser while in the middle of
+** parsing a CREATE TABLE statement.  The pFirst token is the first
+** token in the sequence of tokens that describe the type of the
+** column currently under construction.   pLast is the last token
+** in the sequence.  Use this information to construct a string
+** that contains the typename of the column and store that string
+** in zType.
+*/ 
+void sqlite3AddColumnType(Parse *pParse, Token *pType){
+  Table *p;
+  int i;
+  Column *pCol;
+  sqlite3 *db;
+
+  if( (p = pParse->pNewTable)==0 ) return;
+  i = p->nCol-1;
+  if( i<0 ) return;
+  pCol = &p->aCol[i];
+  db = pParse->db;
+  sqlite3DbFree(db, pCol->zType);
+  pCol->zType = sqlite3NameFromToken(db, pType);
+  pCol->affinity = sqlite3AffinityType(pType);
+}
+
+/*
+** The expression is the default value for the most recently added column
+** of the table currently under construction.
+**
+** Default value expressions must be constant.  Raise an exception if this
+** is not the case.
+**
+** This routine is called by the parser while in the middle of
+** parsing a CREATE TABLE statement.
+*/
+void sqlite3AddDefaultValue(Parse *pParse, Expr *pExpr){
+  Table *p;
+  Column *pCol;
+  sqlite3 *db = pParse->db;
+  if( (p = pParse->pNewTable)!=0 ){
+    pCol = &(p->aCol[p->nCol-1]);
+    if( !sqlite3ExprIsConstantOrFunction(pExpr) ){
+      sqlite3ErrorMsg(pParse, "default value of column [%s] is not constant",
+          pCol->zName);
+    }else{
+      Expr *pCopy;
+      sqlite3ExprDelete(db, pCol->pDflt);
+      pCol->pDflt = pCopy = sqlite3ExprDup(db, pExpr);
+      if( pCopy ){
+        sqlite3TokenCopy(db, &pCopy->span, &pExpr->span);
+      }
+    }
+  }
+  sqlite3ExprDelete(db, pExpr);
+}
+
+/*
+** Designate the PRIMARY KEY for the table.  pList is a list of names 
+** of columns that form the primary key.  If pList is NULL, then the
+** most recently added column of the table is the primary key.
+**
+** A table can have at most one primary key.  If the table already has
+** a primary key (and this is the second primary key) then create an
+** error.
+**
+** If the PRIMARY KEY is on a single column whose datatype is INTEGER,
+** then we will try to use that column as the rowid.  Set the Table.iPKey
+** field of the table under construction to be the index of the
+** INTEGER PRIMARY KEY column.  Table.iPKey is set to -1 if there is
+** no INTEGER PRIMARY KEY.
+**
+** If the key is not an INTEGER PRIMARY KEY, then create a unique
+** index for the key.  No index is created for INTEGER PRIMARY KEYs.
+*/
+void sqlite3AddPrimaryKey(
+  Parse *pParse,    /* Parsing context */
+  ExprList *pList,  /* List of field names to be indexed */
+  int onError,      /* What to do with a uniqueness conflict */
+  int autoInc,      /* True if the AUTOINCREMENT keyword is present */
+  int sortOrder     /* SQLITE_SO_ASC or SQLITE_SO_DESC */
+){
+  Table *pTab = pParse->pNewTable;
+  char *zType = 0;
+  int iCol = -1, i;
+  if( pTab==0 || IN_DECLARE_VTAB ) goto primary_key_exit;
+  if( pTab->hasPrimKey ){
+    sqlite3ErrorMsg(pParse, 
+      "table \"%s\" has more than one primary key", pTab->zName);
+    goto primary_key_exit;
+  }
+  pTab->hasPrimKey = 1;
+  if( pList==0 ){
+    iCol = pTab->nCol - 1;
+    pTab->aCol[iCol].isPrimKey = 1;
+  }else{
+    for(i=0; i<pList->nExpr; i++){
+      for(iCol=0; iCol<pTab->nCol; iCol++){
+        if( sqlite3StrICmp(pList->a[i].zName, pTab->aCol[iCol].zName)==0 ){
+          break;
+        }
+      }
+      if( iCol<pTab->nCol ){
+        pTab->aCol[iCol].isPrimKey = 1;
+      }
+    }
+    if( pList->nExpr>1 ) iCol = -1;
+  }
+  if( iCol>=0 && iCol<pTab->nCol ){
+    zType = pTab->aCol[iCol].zType;
+  }
+  if( zType && sqlite3StrICmp(zType, "INTEGER")==0
+        && sortOrder==SQLITE_SO_ASC ){
+    pTab->iPKey = iCol;
+    pTab->keyConf = onError;
+    pTab->autoInc = autoInc;
+  }else if( autoInc ){
+#ifndef SQLITE_OMIT_AUTOINCREMENT
+    sqlite3ErrorMsg(pParse, "AUTOINCREMENT is only allowed on an "
+       "INTEGER PRIMARY KEY");
+#endif
+  }else{
+    sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0, 0, sortOrder, 0);
+    pList = 0;
+  }
+
+primary_key_exit:
+  sqlite3ExprListDelete(pParse->db, pList);
+  return;
+}
+
+/*
+** Add a new CHECK constraint to the table currently under construction.
+*/
+void sqlite3AddCheckConstraint(
+  Parse *pParse,    /* Parsing context */
+  Expr *pCheckExpr  /* The check expression */
+){
+  sqlite3 *db = pParse->db;
+#ifndef SQLITE_OMIT_CHECK
+  Table *pTab = pParse->pNewTable;
+  if( pTab && !IN_DECLARE_VTAB ){
+    /* The CHECK expression must be duplicated so that tokens refer
+    ** to malloced space and not the (ephemeral) text of the CREATE TABLE
+    ** statement */
+    pTab->pCheck = sqlite3ExprAnd(db, pTab->pCheck, 
+                                  sqlite3ExprDup(db, pCheckExpr));
+  }
+#endif
+  sqlite3ExprDelete(db, pCheckExpr);
+}
+
+/*
+** Set the collation function of the most recently parsed table column
+** to the CollSeq given.
+*/
+void sqlite3AddCollateType(Parse *pParse, Token *pToken){
+  Table *p;
+  int i;
+  char *zColl;              /* Dequoted name of collation sequence */
+  sqlite3 *db;
+
+  if( (p = pParse->pNewTable)==0 ) return;
+  i = p->nCol-1;
+  db = pParse->db;
+  zColl = sqlite3NameFromToken(db, pToken);
+  if( !zColl ) return;
+
+  if( sqlite3LocateCollSeq(pParse, zColl, -1) ){
+    Index *pIdx;
+    p->aCol[i].zColl = zColl;
+  
+    /* If the column is declared as "<name> PRIMARY KEY COLLATE <type>",
+    ** then an index may have been created on this column before the
+    ** collation type was added. Correct this if it is the case.
+    */
+    for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
+      assert( pIdx->nColumn==1 );
+      if( pIdx->aiColumn[0]==i ){
+        pIdx->azColl[0] = p->aCol[i].zColl;
+      }
+    }
+  }else{
+    sqlite3DbFree(db, zColl);
+  }
+}
+
+/*
+** This function returns the collation sequence for database native text
+** encoding identified by the string zName, length nName.
+**
+** If the requested collation sequence is not available, or not available
+** in the database native encoding, the collation factory is invoked to
+** request it. If the collation factory does not supply such a sequence,
+** and the sequence is available in another text encoding, then that is
+** returned instead.
+**
+** If no versions of the requested collations sequence are available, or
+** another error occurs, NULL is returned and an error message written into
+** pParse.
+**
+** This routine is a wrapper around sqlite3FindCollSeq().  This routine
+** invokes the collation factory if the named collation cannot be found
+** and generates an error message.
+*/
+CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName){
+  sqlite3 *db = pParse->db;
+  u8 enc = ENC(db);
+  u8 initbusy = db->init.busy;
+  CollSeq *pColl;
+
+  pColl = sqlite3FindCollSeq(db, enc, zName, nName, initbusy);
+  if( !initbusy && (!pColl || !pColl->xCmp) ){
+    pColl = sqlite3GetCollSeq(db, pColl, zName, nName);
+    if( !pColl ){
+      if( nName<0 ){
+        nName = sqlite3Strlen(db, zName);
+      }
+      sqlite3ErrorMsg(pParse, "no such collation sequence: %.*s", nName, zName);
+      pColl = 0;
+    }
+  }
+
+  return pColl;
+}
+
+
+/*
+** Generate code that will increment the schema cookie.
+**
+** The schema cookie is used to determine when the schema for the
+** database changes.  After each schema change, the cookie value
+** changes.  When a process first reads the schema it records the
+** cookie.  Thereafter, whenever it goes to access the database,
+** it checks the cookie to make sure the schema has not changed
+** since it was last read.
+**
+** This plan is not completely bullet-proof.  It is possible for
+** the schema to change multiple times and for the cookie to be
+** set back to prior value.  But schema changes are infrequent
+** and the probability of hitting the same cookie value is only
+** 1 chance in 2^32.  So we're safe enough.
+*/
+void sqlite3ChangeCookie(Parse *pParse, int iDb){
+  int r1 = sqlite3GetTempReg(pParse);
+  sqlite3 *db = pParse->db;
+  Vdbe *v = pParse->pVdbe;
+  sqlite3VdbeAddOp2(v, OP_Integer, db->aDb[iDb].pSchema->schema_cookie+1, r1);
+  sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, 0, r1);
+  sqlite3ReleaseTempReg(pParse, r1);
+}
+
+/*
+** Measure the number of characters needed to output the given
+** identifier.  The number returned includes any quotes used
+** but does not include the null terminator.
+**
+** The estimate is conservative.  It might be larger that what is
+** really needed.
+*/
+static int identLength(const char *z){
+  int n;
+  for(n=0; *z; n++, z++){
+    if( *z=='"' ){ n++; }
+  }
+  return n + 2;
+}
+
+/*
+** Write an identifier onto the end of the given string.  Add
+** quote characters as needed.
+*/
+static void identPut(char *z, int *pIdx, char *zSignedIdent){
+  unsigned char *zIdent = (unsigned char*)zSignedIdent;
+  int i, j, needQuote;
+  i = *pIdx;
+  for(j=0; zIdent[j]; j++){
+    if( !isalnum(zIdent[j]) && zIdent[j]!='_' ) break;
+  }
+  needQuote =  zIdent[j]!=0 || isdigit(zIdent[0])
+                  || sqlite3KeywordCode(zIdent, j)!=TK_ID;
+  if( needQuote ) z[i++] = '"';
+  for(j=0; zIdent[j]; j++){
+    z[i++] = zIdent[j];
+    if( zIdent[j]=='"' ) z[i++] = '"';
+  }
+  if( needQuote ) z[i++] = '"';
+  z[i] = 0;
+  *pIdx = i;
+}
+
+/*
+** Generate a CREATE TABLE statement appropriate for the given
+** table.  Memory to hold the text of the statement is obtained
+** from sqliteMalloc() and must be freed by the calling function.
+*/
+static char *createTableStmt(sqlite3 *db, Table *p, int isTemp){
+  int i, k, n;
+  char *zStmt;
+  char *zSep, *zSep2, *zEnd, *z;
+  Column *pCol;
+  n = 0;
+  for(pCol = p->aCol, i=0; i<p->nCol; i++, pCol++){
+    n += identLength(pCol->zName);
+    z = pCol->zType;
+    if( z ){
+      n += (strlen(z) + 1);
+    }
+  }
+  n += identLength(p->zName);
+  if( n<50 ){
+    zSep = "";
+    zSep2 = ",";
+    zEnd = ")";
+  }else{
+    zSep = "\n  ";
+    zSep2 = ",\n  ";
+    zEnd = "\n)";
+  }
+  n += 35 + 6*p->nCol;
+  zStmt = sqlite3Malloc( n );
+  if( zStmt==0 ){
+    db->mallocFailed = 1;
+    return 0;
+  }
+  sqlite3_snprintf(n, zStmt,
+                  !OMIT_TEMPDB&&isTemp ? "CREATE TEMP TABLE ":"CREATE TABLE ");
+  k = strlen(zStmt);
+  identPut(zStmt, &k, p->zName);
+  zStmt[k++] = '(';
+  for(pCol=p->aCol, i=0; i<p->nCol; i++, pCol++){
+    sqlite3_snprintf(n-k, &zStmt[k], zSep);
+    k += strlen(&zStmt[k]);
+    zSep = zSep2;
+    identPut(zStmt, &k, pCol->zName);
+    if( (z = pCol->zType)!=0 ){
+      zStmt[k++] = ' ';
+      assert( strlen(z)+k+1<=n );
+      sqlite3_snprintf(n-k, &zStmt[k], "%s", z);
+      k += strlen(z);
+    }
+  }
+  sqlite3_snprintf(n-k, &zStmt[k], "%s", zEnd);
+  return zStmt;
+}
+
+/*
+** This routine is called to report the final ")" that terminates
+** a CREATE TABLE statement.
+**
+** The table structure that other action routines have been building
+** is added to the internal hash tables, assuming no errors have
+** occurred.
+**
+** An entry for the table is made in the master table on disk, unless
+** this is a temporary table or db->init.busy==1.  When db->init.busy==1
+** it means we are reading the sqlite_master table because we just
+** connected to the database or because the sqlite_master table has
+** recently changed, so the entry for this table already exists in
+** the sqlite_master table.  We do not want to create it again.
+**
+** If the pSelect argument is not NULL, it means that this routine
+** was called to create a table generated from a 
+** "CREATE TABLE ... AS SELECT ..." statement.  The column names of
+** the new table will match the result set of the SELECT.
+*/
+void sqlite3EndTable(
+  Parse *pParse,          /* Parse context */
+  Token *pCons,           /* The ',' token after the last column defn. */
+  Token *pEnd,            /* The final ')' token in the CREATE TABLE */
+  Select *pSelect         /* Select from a "CREATE ... AS SELECT" */
+){
+  Table *p;
+  sqlite3 *db = pParse->db;
+  int iDb;
+
+  if( (pEnd==0 && pSelect==0) || pParse->nErr || db->mallocFailed ) {
+    return;
+  }
+  p = pParse->pNewTable;
+  if( p==0 ) return;
+
+  assert( !db->init.busy || !pSelect );
+
+  iDb = sqlite3SchemaToIndex(db, p->pSchema);
+
+#ifndef SQLITE_OMIT_CHECK
+  /* Resolve names in all CHECK constraint expressions.
+  */
+  if( p->pCheck ){
+    SrcList sSrc;                   /* Fake SrcList for pParse->pNewTable */
+    NameContext sNC;                /* Name context for pParse->pNewTable */
+
+    memset(&sNC, 0, sizeof(sNC));
+    memset(&sSrc, 0, sizeof(sSrc));
+    sSrc.nSrc = 1;
+    sSrc.a[0].zName = p->zName;
+    sSrc.a[0].pTab = p;
+    sSrc.a[0].iCursor = -1;
+    sNC.pParse = pParse;
+    sNC.pSrcList = &sSrc;
+    sNC.isCheck = 1;
+    if( sqlite3ExprResolveNames(&sNC, p->pCheck) ){
+      return;
+    }
+  }
+#endif /* !defined(SQLITE_OMIT_CHECK) */
+
+  /* If the db->init.busy is 1 it means we are reading the SQL off the
+  ** "sqlite_master" or "sqlite_temp_master" table on the disk.
+  ** So do not write to the disk again.  Extract the root page number
+  ** for the table from the db->init.newTnum field.  (The page number
+  ** should have been put there by the sqliteOpenCb routine.)
+  */
+  if( db->init.busy ){
+    p->tnum = db->init.newTnum;
+  }
+
+  /* If not initializing, then create a record for the new table
+  ** in the SQLITE_MASTER table of the database.  The record number
+  ** for the new table entry should already be on the stack.
+  **
+  ** If this is a TEMPORARY table, write the entry into the auxiliary
+  ** file instead of into the main database file.
+  */
+  if( !db->init.busy ){
+    int n;
+    Vdbe *v;
+    char *zType;    /* "view" or "table" */
+    char *zType2;   /* "VIEW" or "TABLE" */
+    char *zStmt;    /* Text of the CREATE TABLE or CREATE VIEW statement */
+
+    v = sqlite3GetVdbe(pParse);
+    if( v==0 ) return;
+
+    sqlite3VdbeAddOp1(v, OP_Close, 0);
+
+    /* Create the rootpage for the new table and push it onto the stack.
+    ** A view has no rootpage, so just push a zero onto the stack for
+    ** views.  Initialize zType at the same time.
+    */
+    if( p->pSelect==0 ){
+      /* A regular table */
+      zType = "table";
+      zType2 = "TABLE";
+#ifndef SQLITE_OMIT_VIEW
+    }else{
+      /* A view */
+      zType = "view";
+      zType2 = "VIEW";
+#endif
+    }
+
+    /* If this is a CREATE TABLE xx AS SELECT ..., execute the SELECT
+    ** statement to populate the new table. The root-page number for the
+    ** new table is on the top of the vdbe stack.
+    **
+    ** Once the SELECT has been coded by sqlite3Select(), it is in a
+    ** suitable state to query for the column names and types to be used
+    ** by the new table.
+    **
+    ** A shared-cache write-lock is not required to write to the new table,
+    ** as a schema-lock must have already been obtained to create it. Since
+    ** a schema-lock excludes all other database users, the write-lock would
+    ** be redundant.
+    */
+    if( pSelect ){
+      SelectDest dest;
+      Table *pSelTab;
+
+      assert(pParse->nTab==0);
+      sqlite3VdbeAddOp3(v, OP_OpenWrite, 1, pParse->regRoot, iDb);
+      sqlite3VdbeChangeP5(v, 1);
+      pParse->nTab = 2;
+      sqlite3SelectDestInit(&dest, SRT_Table, 1);
+      sqlite3Select(pParse, pSelect, &dest, 0, 0, 0);
+      sqlite3VdbeAddOp1(v, OP_Close, 1);
+      if( pParse->nErr==0 ){
+        pSelTab = sqlite3ResultSetOfSelect(pParse, 0, pSelect);
+        if( pSelTab==0 ) return;
+        assert( p->aCol==0 );
+        p->nCol = pSelTab->nCol;
+        p->aCol = pSelTab->aCol;
+        pSelTab->nCol = 0;
+        pSelTab->aCol = 0;
+        sqlite3DeleteTable(pSelTab);
+      }
+    }
+
+    /* Compute the complete text of the CREATE statement */
+    if( pSelect ){
+      zStmt = createTableStmt(db, p, p->pSchema==db->aDb[1].pSchema);
+    }else{
+      n = pEnd->z - pParse->sNameToken.z + 1;
+      zStmt = sqlite3MPrintf(db, 
+          "CREATE %s %.*s", zType2, n, pParse->sNameToken.z
+      );
+    }
+
+    /* A slot for the record has already been allocated in the 
+    ** SQLITE_MASTER table.  We just need to update that slot with all
+    ** the information we've collected.  The rowid for the preallocated
+    ** slot is the 2nd item on the stack.  The top of the stack is the
+    ** root page for the new table (or a 0 if this is a view).
+    */
+    sqlite3NestedParse(pParse,
+      "UPDATE %Q.%s "
+         "SET type='%s', name=%Q, tbl_name=%Q, rootpage=#%d, sql=%Q "
+       "WHERE rowid=#%d",
+      db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
+      zType,
+      p->zName,
+      p->zName,
+      pParse->regRoot,
+      zStmt,
+      pParse->regRowid
+    );
+    sqlite3DbFree(db, zStmt);
+    sqlite3ChangeCookie(pParse, iDb);
+
+#ifndef SQLITE_OMIT_AUTOINCREMENT
+    /* Check to see if we need to create an sqlite_sequence table for
+    ** keeping track of autoincrement keys.
+    */
+    if( p->autoInc ){
+      Db *pDb = &db->aDb[iDb];
+      if( pDb->pSchema->pSeqTab==0 ){
+        sqlite3NestedParse(pParse,
+          "CREATE TABLE %Q.sqlite_sequence(name,seq)",
+          pDb->zName
+        );
+      }
+    }
+#endif
+
+    /* Reparse everything to update our internal data structures */
+    sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0,
+        sqlite3MPrintf(db, "tbl_name='%q'",p->zName), P4_DYNAMIC);
+  }
+
+
+  /* Add the table to the in-memory representation of the database.
+  */
+  if( db->init.busy && pParse->nErr==0 ){
+    Table *pOld;
+    FKey *pFKey; 
+    Schema *pSchema = p->pSchema;
+    pOld = sqlite3HashInsert(&pSchema->tblHash, p->zName, strlen(p->zName)+1,p);
+    if( pOld ){
+      assert( p==pOld );  /* Malloc must have failed inside HashInsert() */
+      db->mallocFailed = 1;
+      return;
+    }
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+    for(pFKey=p->pFKey; pFKey; pFKey=pFKey->pNextFrom){
+      void *data;
+      int nTo = strlen(pFKey->zTo) + 1;
+      pFKey->pNextTo = sqlite3HashFind(&pSchema->aFKey, pFKey->zTo, nTo);
+      data = sqlite3HashInsert(&pSchema->aFKey, pFKey->zTo, nTo, pFKey);
+      if( data==(void *)pFKey ){
+        db->mallocFailed = 1;
+      }
+    }
+#endif
+    pParse->pNewTable = 0;
+    db->nTable++;
+    db->flags |= SQLITE_InternChanges;
+
+#ifndef SQLITE_OMIT_ALTERTABLE
+    if( !p->pSelect ){
+      const char *zName = (const char *)pParse->sNameToken.z;
+      int nName;
+      assert( !pSelect && pCons && pEnd );
+      if( pCons->z==0 ){
+        pCons = pEnd;
+      }
+      nName = (const char *)pCons->z - zName;
+      p->addColOffset = 13 + sqlite3Utf8CharLen(zName, nName);
+    }
+#endif
+  }
+}
+
+#ifndef SQLITE_OMIT_VIEW
+/*
+** The parser calls this routine in order to create a new VIEW
+*/
+void sqlite3CreateView(
+  Parse *pParse,     /* The parsing context */
+  Token *pBegin,     /* The CREATE token that begins the statement */
+  Token *pName1,     /* The token that holds the name of the view */
+  Token *pName2,     /* The token that holds the name of the view */
+  Select *pSelect,   /* A SELECT statement that will become the new view */
+  int isTemp,        /* TRUE for a TEMPORARY view */
+  int noErr          /* Suppress error messages if VIEW already exists */
+){
+  Table *p;
+  int n;
+  const unsigned char *z;
+  Token sEnd;
+  DbFixer sFix;
+  Token *pName;
+  int iDb;
+  sqlite3 *db = pParse->db;
+
+  if( pParse->nVar>0 ){
+    sqlite3ErrorMsg(pParse, "parameters are not allowed in views");
+    sqlite3SelectDelete(db, pSelect);
+    return;
+  }
+  sqlite3StartTable(pParse, pName1, pName2, isTemp, 1, 0, noErr);
+  p = pParse->pNewTable;
+  if( p==0 || pParse->nErr ){
+    sqlite3SelectDelete(db, pSelect);
+    return;
+  }
+  sqlite3TwoPartName(pParse, pName1, pName2, &pName);
+  iDb = sqlite3SchemaToIndex(db, p->pSchema);
+  if( sqlite3FixInit(&sFix, pParse, iDb, "view", pName)
+    && sqlite3FixSelect(&sFix, pSelect)
+  ){
+    sqlite3SelectDelete(db, pSelect);
+    return;
+  }
+
+  /* Make a copy of the entire SELECT statement that defines the view.
+  ** This will force all the Expr.token.z values to be dynamically
+  ** allocated rather than point to the input string - which means that
+  ** they will persist after the current sqlite3_exec() call returns.
+  */
+  p->pSelect = sqlite3SelectDup(db, pSelect);
+  sqlite3SelectDelete(db, pSelect);
+  if( db->mallocFailed ){
+    return;
+  }
+  if( !db->init.busy ){
+    sqlite3ViewGetColumnNames(pParse, p);
+  }
+
+  /* Locate the end of the CREATE VIEW statement.  Make sEnd point to
+  ** the end.
+  */
+  sEnd = pParse->sLastToken;
+  if( sEnd.z[0]!=0 && sEnd.z[0]!=';' ){
+    sEnd.z += sEnd.n;
+  }
+  sEnd.n = 0;
+  n = sEnd.z - pBegin->z;
+  z = (const unsigned char*)pBegin->z;
+  while( n>0 && (z[n-1]==';' || isspace(z[n-1])) ){ n--; }
+  sEnd.z = &z[n-1];
+  sEnd.n = 1;
+
+  /* Use sqlite3EndTable() to add the view to the SQLITE_MASTER table */
+  sqlite3EndTable(pParse, 0, &sEnd, 0);
+  return;
+}
+#endif /* SQLITE_OMIT_VIEW */
+
+#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
+/*
+** The Table structure pTable is really a VIEW.  Fill in the names of
+** the columns of the view in the pTable structure.  Return the number
+** of errors.  If an error is seen leave an error message in pParse->zErrMsg.
+*/
+int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
+  Table *pSelTab;   /* A fake table from which we get the result set */
+  Select *pSel;     /* Copy of the SELECT that implements the view */
+  int nErr = 0;     /* Number of errors encountered */
+  int n;            /* Temporarily holds the number of cursors assigned */
+  sqlite3 *db = pParse->db;  /* Database connection for malloc errors */
+  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
+
+  assert( pTable );
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if( sqlite3VtabCallConnect(pParse, pTable) ){
+    return SQLITE_ERROR;
+  }
+  if( IsVirtual(pTable) ) return 0;
+#endif
+
+#ifndef SQLITE_OMIT_VIEW
+  /* A positive nCol means the columns names for this view are
+  ** already known.
+  */
+  if( pTable->nCol>0 ) return 0;
+
+  /* A negative nCol is a special marker meaning that we are currently
+  ** trying to compute the column names.  If we enter this routine with
+  ** a negative nCol, it means two or more views form a loop, like this:
+  **
+  **     CREATE VIEW one AS SELECT * FROM two;
+  **     CREATE VIEW two AS SELECT * FROM one;
+  **
+  ** Actually, this error is caught previously and so the following test
+  ** should always fail.  But we will leave it in place just to be safe.
+  */
+  if( pTable->nCol<0 ){
+    sqlite3ErrorMsg(pParse, "view %s is circularly defined", pTable->zName);
+    return 1;
+  }
+  assert( pTable->nCol>=0 );
+
+  /* If we get this far, it means we need to compute the table names.
+  ** Note that the call to sqlite3ResultSetOfSelect() will expand any
+  ** "*" elements in the results set of the view and will assign cursors
+  ** to the elements of the FROM clause.  But we do not want these changes
+  ** to be permanent.  So the computation is done on a copy of the SELECT
+  ** statement that defines the view.
+  */
+  assert( pTable->pSelect );
+  pSel = sqlite3SelectDup(db, pTable->pSelect);
+  if( pSel ){
+    n = pParse->nTab;
+    sqlite3SrcListAssignCursors(pParse, pSel->pSrc);
+    pTable->nCol = -1;
+#ifndef SQLITE_OMIT_AUTHORIZATION
+    xAuth = db->xAuth;
+    db->xAuth = 0;
+    pSelTab = sqlite3ResultSetOfSelect(pParse, 0, pSel);
+    db->xAuth = xAuth;
+#else
+    pSelTab = sqlite3ResultSetOfSelect(pParse, 0, pSel);
+#endif
+    pParse->nTab = n;
+    if( pSelTab ){
+      assert( pTable->aCol==0 );
+      pTable->nCol = pSelTab->nCol;
+      pTable->aCol = pSelTab->aCol;
+      pSelTab->nCol = 0;
+      pSelTab->aCol = 0;
+      sqlite3DeleteTable(pSelTab);
+      pTable->pSchema->flags |= DB_UnresetViews;
+    }else{
+      pTable->nCol = 0;
+      nErr++;
+    }
+    sqlite3SelectDelete(db, pSel);
+  } else {
+    nErr++;
+  }
+#endif /* SQLITE_OMIT_VIEW */
+  return nErr;  
+}
+#endif /* !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE) */
+
+#ifndef SQLITE_OMIT_VIEW
+/*
+** Clear the column names from every VIEW in database idx.
+*/
+static void sqliteViewResetAll(sqlite3 *db, int idx){
+  HashElem *i;
+  if( !DbHasProperty(db, idx, DB_UnresetViews) ) return;
+  for(i=sqliteHashFirst(&db->aDb[idx].pSchema->tblHash); i;i=sqliteHashNext(i)){
+    Table *pTab = sqliteHashData(i);
+    if( pTab->pSelect ){
+      sqliteResetColumnNames(pTab);
+    }
+  }
+  DbClearProperty(db, idx, DB_UnresetViews);
+}
+#else
+# define sqliteViewResetAll(A,B)
+#endif /* SQLITE_OMIT_VIEW */
+
+/*
+** This function is called by the VDBE to adjust the internal schema
+** used by SQLite when the btree layer moves a table root page. The
+** root-page of a table or index in database iDb has changed from iFrom
+** to iTo.
+**
+** Ticket #1728:  The symbol table might still contain information
+** on tables and/or indices that are the process of being deleted.
+** If you are unlucky, one of those deleted indices or tables might
+** have the same rootpage number as the real table or index that is
+** being moved.  So we cannot stop searching after the first match 
+** because the first match might be for one of the deleted indices
+** or tables and not the table/index that is actually being moved.
+** We must continue looping until all tables and indices with
+** rootpage==iFrom have been converted to have a rootpage of iTo
+** in order to be certain that we got the right one.
+*/
+#ifndef SQLITE_OMIT_AUTOVACUUM
+void sqlite3RootPageMoved(Db *pDb, int iFrom, int iTo){
+  HashElem *pElem;
+  Hash *pHash;
+
+  pHash = &pDb->pSchema->tblHash;
+  for(pElem=sqliteHashFirst(pHash); pElem; pElem=sqliteHashNext(pElem)){
+    Table *pTab = sqliteHashData(pElem);
+    if( pTab->tnum==iFrom ){
+      pTab->tnum = iTo;
+    }
+  }
+  pHash = &pDb->pSchema->idxHash;
+  for(pElem=sqliteHashFirst(pHash); pElem; pElem=sqliteHashNext(pElem)){
+    Index *pIdx = sqliteHashData(pElem);
+    if( pIdx->tnum==iFrom ){
+      pIdx->tnum = iTo;
+    }
+  }
+}
+#endif
+
+/*
+** Write code to erase the table with root-page iTable from database iDb.
+** Also write code to modify the sqlite_master table and internal schema
+** if a root-page of another table is moved by the btree-layer whilst
+** erasing iTable (this can happen with an auto-vacuum database).
+*/ 
+static void destroyRootPage(Parse *pParse, int iTable, int iDb){
+  Vdbe *v = sqlite3GetVdbe(pParse);
+  int r1 = sqlite3GetTempReg(pParse);
+  sqlite3VdbeAddOp3(v, OP_Destroy, iTable, r1, iDb);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+  /* OP_Destroy stores an in integer r1. If this integer
+  ** is non-zero, then it is the root page number of a table moved to
+  ** location iTable. The following code modifies the sqlite_master table to
+  ** reflect this.
+  **
+  ** The "#%d" in the SQL is a special constant that means whatever value
+  ** is on the top of the stack.  See sqlite3RegisterExpr().
+  */
+  sqlite3NestedParse(pParse, 
+     "UPDATE %Q.%s SET rootpage=%d WHERE #%d AND rootpage=#%d",
+     pParse->db->aDb[iDb].zName, SCHEMA_TABLE(iDb), iTable, r1, r1);
+#endif
+  sqlite3ReleaseTempReg(pParse, r1);
+}
+
+/*
+** Write VDBE code to erase table pTab and all associated indices on disk.
+** Code to update the sqlite_master tables and internal schema definitions
+** in case a root-page belonging to another table is moved by the btree layer
+** is also added (this can happen with an auto-vacuum database).
+*/
+static void destroyTable(Parse *pParse, Table *pTab){
+#ifdef SQLITE_OMIT_AUTOVACUUM
+  Index *pIdx;
+  int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+  destroyRootPage(pParse, pTab->tnum, iDb);
+  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+    destroyRootPage(pParse, pIdx->tnum, iDb);
+  }
+#else
+  /* If the database may be auto-vacuum capable (if SQLITE_OMIT_AUTOVACUUM
+  ** is not defined), then it is important to call OP_Destroy on the
+  ** table and index root-pages in order, starting with the numerically 
+  ** largest root-page number. This guarantees that none of the root-pages
+  ** to be destroyed is relocated by an earlier OP_Destroy. i.e. if the
+  ** following were coded:
+  **
+  ** OP_Destroy 4 0
+  ** ...
+  ** OP_Destroy 5 0
+  **
+  ** and root page 5 happened to be the largest root-page number in the
+  ** database, then root page 5 would be moved to page 4 by the 
+  ** "OP_Destroy 4 0" opcode. The subsequent "OP_Destroy 5 0" would hit
+  ** a free-list page.
+  */
+  int iTab = pTab->tnum;
+  int iDestroyed = 0;
+
+  while( 1 ){
+    Index *pIdx;
+    int iLargest = 0;
+
+    if( iDestroyed==0 || iTab<iDestroyed ){
+      iLargest = iTab;
+    }
+    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+      int iIdx = pIdx->tnum;
+      assert( pIdx->pSchema==pTab->pSchema );
+      if( (iDestroyed==0 || (iIdx<iDestroyed)) && iIdx>iLargest ){
+        iLargest = iIdx;
+      }
+    }
+    if( iLargest==0 ){
+      return;
+    }else{
+      int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+      destroyRootPage(pParse, iLargest, iDb);
+      iDestroyed = iLargest;
+    }
+  }
+#endif
+}
+
+/*
+** This routine is called to do the work of a DROP TABLE statement.
+** pName is the name of the table to be dropped.
+*/
+void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView, int noErr){
+  Table *pTab;
+  Vdbe *v;
+  sqlite3 *db = pParse->db;
+  int iDb;
+
+  if( pParse->nErr || db->mallocFailed ){
+    goto exit_drop_table;
+  }
+  assert( pName->nSrc==1 );
+  pTab = sqlite3LocateTable(pParse, isView, 
+                            pName->a[0].zName, pName->a[0].zDatabase);
+
+  if( pTab==0 ){
+    if( noErr ){
+      sqlite3ErrorClear(pParse);
+    }
+    goto exit_drop_table;
+  }
+  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+  assert( iDb>=0 && iDb<db->nDb );
+
+  /* If pTab is a virtual table, call ViewGetColumnNames() to ensure
+  ** it is initialized.
+  */
+  if( IsVirtual(pTab) && sqlite3ViewGetColumnNames(pParse, pTab) ){
+    goto exit_drop_table;
+  }
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  {
+    int code;
+    const char *zTab = SCHEMA_TABLE(iDb);
+    const char *zDb = db->aDb[iDb].zName;
+    const char *zArg2 = 0;
+    if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb)){
+      goto exit_drop_table;
+    }
+    if( isView ){
+      if( !OMIT_TEMPDB && iDb==1 ){
+        code = SQLITE_DROP_TEMP_VIEW;
+      }else{
+        code = SQLITE_DROP_VIEW;
+      }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    }else if( IsVirtual(pTab) ){
+      code = SQLITE_DROP_VTABLE;
+      zArg2 = pTab->pMod->zName;
+#endif
+    }else{
+      if( !OMIT_TEMPDB && iDb==1 ){
+        code = SQLITE_DROP_TEMP_TABLE;
+      }else{
+        code = SQLITE_DROP_TABLE;
+      }
+    }
+    if( sqlite3AuthCheck(pParse, code, pTab->zName, zArg2, zDb) ){
+      goto exit_drop_table;
+    }
+    if( sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){
+      goto exit_drop_table;
+    }
+  }
+#endif
+  if( pTab->readOnly || pTab==db->aDb[iDb].pSchema->pSeqTab ){
+    sqlite3ErrorMsg(pParse, "table %s may not be dropped", pTab->zName);
+    goto exit_drop_table;
+  }
+
+#ifndef SQLITE_OMIT_VIEW
+  /* Ensure DROP TABLE is not used on a view, and DROP VIEW is not used
+  ** on a table.
+  */
+  if( isView && pTab->pSelect==0 ){
+    sqlite3ErrorMsg(pParse, "use DROP TABLE to delete table %s", pTab->zName);
+    goto exit_drop_table;
+  }
+  if( !isView && pTab->pSelect ){
+    sqlite3ErrorMsg(pParse, "use DROP VIEW to delete view %s", pTab->zName);
+    goto exit_drop_table;
+  }
+#endif
+
+  /* Generate code to remove the table from the master table
+  ** on disk.
+  */
+  v = sqlite3GetVdbe(pParse);
+  if( v ){
+    Trigger *pTrigger;
+    Db *pDb = &db->aDb[iDb];
+    sqlite3BeginWriteOperation(pParse, 1, iDb);
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( IsVirtual(pTab) ){
+      Vdbe *v = sqlite3GetVdbe(pParse);
+      if( v ){
+        sqlite3VdbeAddOp0(v, OP_VBegin);
+      }
+    }
+#endif
+
+    /* Drop all triggers associated with the table being dropped. Code
+    ** is generated to remove entries from sqlite_master and/or
+    ** sqlite_temp_master if required.
+    */
+    pTrigger = pTab->pTrigger;
+    while( pTrigger ){
+      assert( pTrigger->pSchema==pTab->pSchema || 
+          pTrigger->pSchema==db->aDb[1].pSchema );
+      sqlite3DropTriggerPtr(pParse, pTrigger);
+      pTrigger = pTrigger->pNext;
+    }
+
+#ifndef SQLITE_OMIT_AUTOINCREMENT
+    /* Remove any entries of the sqlite_sequence table associated with
+    ** the table being dropped. This is done before the table is dropped
+    ** at the btree level, in case the sqlite_sequence table needs to
+    ** move as a result of the drop (can happen in auto-vacuum mode).
+    */
+    if( pTab->autoInc ){
+      sqlite3NestedParse(pParse,
+        "DELETE FROM %s.sqlite_sequence WHERE name=%Q",
+        pDb->zName, pTab->zName
+      );
+    }
+#endif
+
+    /* Drop all SQLITE_MASTER table and index entries that refer to the
+    ** table. The program name loops through the master table and deletes
+    ** every row that refers to a table of the same name as the one being
+    ** dropped. Triggers are handled seperately because a trigger can be
+    ** created in the temp database that refers to a table in another
+    ** database.
+    */
+    sqlite3NestedParse(pParse, 
+        "DELETE FROM %Q.%s WHERE tbl_name=%Q and type!='trigger'",
+        pDb->zName, SCHEMA_TABLE(iDb), pTab->zName);
+
+    /* Drop any statistics from the sqlite_stat1 table, if it exists */
+    if( sqlite3FindTable(db, "sqlite_stat1", db->aDb[iDb].zName) ){
+      sqlite3NestedParse(pParse,
+        "DELETE FROM %Q.sqlite_stat1 WHERE tbl=%Q", pDb->zName, pTab->zName
+      );
+    }
+
+    if( !isView && !IsVirtual(pTab) ){
+      destroyTable(pParse, pTab);
+    }
+
+    /* Remove the table entry from SQLite's internal schema and modify
+    ** the schema cookie.
+    */
+    if( IsVirtual(pTab) ){
+      sqlite3VdbeAddOp4(v, OP_VDestroy, iDb, 0, 0, pTab->zName, 0);
+    }
+    sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0);
+    sqlite3ChangeCookie(pParse, iDb);
+  }
+  sqliteViewResetAll(db, iDb);
+
+exit_drop_table:
+  sqlite3SrcListDelete(db, pName);
+}
+
+/*
+** This routine is called to create a new foreign key on the table
+** currently under construction.  pFromCol determines which columns
+** in the current table point to the foreign key.  If pFromCol==0 then
+** connect the key to the last column inserted.  pTo is the name of
+** the table referred to.  pToCol is a list of tables in the other
+** pTo table that the foreign key points to.  flags contains all
+** information about the conflict resolution algorithms specified
+** in the ON DELETE, ON UPDATE and ON INSERT clauses.
+**
+** An FKey structure is created and added to the table currently
+** under construction in the pParse->pNewTable field.  The new FKey
+** is not linked into db->aFKey at this point - that does not happen
+** until sqlite3EndTable().
+**
+** The foreign key is set for IMMEDIATE processing.  A subsequent call
+** to sqlite3DeferForeignKey() might change this to DEFERRED.
+*/
+void sqlite3CreateForeignKey(
+  Parse *pParse,       /* Parsing context */
+  ExprList *pFromCol,  /* Columns in this table that point to other table */
+  Token *pTo,          /* Name of the other table */
+  ExprList *pToCol,    /* Columns in the other table */
+  int flags            /* Conflict resolution algorithms. */
+){
+  sqlite3 *db = pParse->db;
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+  FKey *pFKey = 0;
+  Table *p = pParse->pNewTable;
+  int nByte;
+  int i;
+  int nCol;
+  char *z;
+
+  assert( pTo!=0 );
+  if( p==0 || pParse->nErr || IN_DECLARE_VTAB ) goto fk_end;
+  if( pFromCol==0 ){
+    int iCol = p->nCol-1;
+    if( iCol<0 ) goto fk_end;
+    if( pToCol && pToCol->nExpr!=1 ){
+      sqlite3ErrorMsg(pParse, "foreign key on %s"
+         " should reference only one column of table %T",
+         p->aCol[iCol].zName, pTo);
+      goto fk_end;
+    }
+    nCol = 1;
+  }else if( pToCol && pToCol->nExpr!=pFromCol->nExpr ){
+    sqlite3ErrorMsg(pParse,
+        "number of columns in foreign key does not match the number of "
+        "columns in the referenced table");
+    goto fk_end;
+  }else{
+    nCol = pFromCol->nExpr;
+  }
+  nByte = sizeof(*pFKey) + nCol*sizeof(pFKey->aCol[0]) + pTo->n + 1;
+  if( pToCol ){
+    for(i=0; i<pToCol->nExpr; i++){
+      nByte += strlen(pToCol->a[i].zName) + 1;
+    }
+  }
+  pFKey = sqlite3DbMallocZero(db, nByte );
+  if( pFKey==0 ){
+    goto fk_end;
+  }
+  pFKey->pFrom = p;
+  pFKey->pNextFrom = p->pFKey;
+  z = (char*)&pFKey[1];
+  pFKey->aCol = (struct sColMap*)z;
+  z += sizeof(struct sColMap)*nCol;
+  pFKey->zTo = z;
+  memcpy(z, pTo->z, pTo->n);
+  z[pTo->n] = 0;
+  z += pTo->n+1;
+  pFKey->pNextTo = 0;
+  pFKey->nCol = nCol;
+  if( pFromCol==0 ){
+    pFKey->aCol[0].iFrom = p->nCol-1;
+  }else{
+    for(i=0; i<nCol; i++){
+      int j;
+      for(j=0; j<p->nCol; j++){
+        if( sqlite3StrICmp(p->aCol[j].zName, pFromCol->a[i].zName)==0 ){
+          pFKey->aCol[i].iFrom = j;
+          break;
+        }
+      }
+      if( j>=p->nCol ){
+        sqlite3ErrorMsg(pParse, 
+          "unknown column \"%s\" in foreign key definition", 
+          pFromCol->a[i].zName);
+        goto fk_end;
+      }
+    }
+  }
+  if( pToCol ){
+    for(i=0; i<nCol; i++){
+      int n = strlen(pToCol->a[i].zName);
+      pFKey->aCol[i].zCol = z;
+      memcpy(z, pToCol->a[i].zName, n);
+      z[n] = 0;
+      z += n+1;
+    }
+  }
+  pFKey->isDeferred = 0;
+  pFKey->deleteConf = flags & 0xff;
+  pFKey->updateConf = (flags >> 8 ) & 0xff;
+  pFKey->insertConf = (flags >> 16 ) & 0xff;
+
+  /* Link the foreign key to the table as the last step.
+  */
+  p->pFKey = pFKey;
+  pFKey = 0;
+
+fk_end:
+  sqlite3DbFree(db, pFKey);
+#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
+  sqlite3ExprListDelete(db, pFromCol);
+  sqlite3ExprListDelete(db, pToCol);
+}
+
+/*
+** This routine is called when an INITIALLY IMMEDIATE or INITIALLY DEFERRED
+** clause is seen as part of a foreign key definition.  The isDeferred
+** parameter is 1 for INITIALLY DEFERRED and 0 for INITIALLY IMMEDIATE.
+** The behavior of the most recently created foreign key is adjusted
+** accordingly.
+*/
+void sqlite3DeferForeignKey(Parse *pParse, int isDeferred){
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+  Table *pTab;
+  FKey *pFKey;
+  if( (pTab = pParse->pNewTable)==0 || (pFKey = pTab->pFKey)==0 ) return;
+  pFKey->isDeferred = isDeferred;
+#endif
+}
+
+/*
+** Generate code that will erase and refill index *pIdx.  This is
+** used to initialize a newly created index or to recompute the
+** content of an index in response to a REINDEX command.
+**
+** if memRootPage is not negative, it means that the index is newly
+** created.  The register specified by memRootPage contains the
+** root page number of the index.  If memRootPage is negative, then
+** the index already exists and must be cleared before being refilled and
+** the root page number of the index is taken from pIndex->tnum.
+*/
+static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
+  Table *pTab = pIndex->pTable;  /* The table that is indexed */
+  int iTab = pParse->nTab;       /* Btree cursor used for pTab */
+  int iIdx = pParse->nTab+1;     /* Btree cursor used for pIndex */
+  int addr1;                     /* Address of top of loop */
+  int tnum;                      /* Root page of index */
+  Vdbe *v;                       /* Generate code into this virtual machine */
+  KeyInfo *pKey;                 /* KeyInfo for index */
+  int regIdxKey;                 /* Registers containing the index key */
+  int regRecord;                 /* Register holding assemblied index record */
+  sqlite3 *db = pParse->db;      /* The database connection */
+  int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  if( sqlite3AuthCheck(pParse, SQLITE_REINDEX, pIndex->zName, 0,
+      db->aDb[iDb].zName ) ){
+    return;
+  }
+#endif
+
+  /* Require a write-lock on the table to perform this operation */
+  sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
+
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 ) return;
+  if( memRootPage>=0 ){
+    tnum = memRootPage;
+  }else{
+    tnum = pIndex->tnum;
+    sqlite3VdbeAddOp2(v, OP_Clear, tnum, iDb);
+  }
+  pKey = sqlite3IndexKeyinfo(pParse, pIndex);
+  sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, tnum, iDb, 
+                    (char *)pKey, P4_KEYINFO_HANDOFF);
+  if( memRootPage>=0 ){
+    sqlite3VdbeChangeP5(v, 1);
+  }
+  sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
+  addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
+  regRecord = sqlite3GetTempReg(pParse);
+  regIdxKey = sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1);
+  if( pIndex->onError!=OE_None ){
+    int j1, j2;
+    int regRowid;
+
+    regRowid = regIdxKey + pIndex->nColumn;
+    j1 = sqlite3VdbeAddOp3(v, OP_IsNull, regIdxKey, 0, pIndex->nColumn);
+    j2 = sqlite3VdbeAddOp4(v, OP_IsUnique, iIdx,
+                           0, regRowid, SQLITE_INT_TO_PTR(regRecord), P4_INT32);
+    sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, OE_Abort, 0,
+                    "indexed columns are not unique", P4_STATIC);
+    sqlite3VdbeJumpHere(v, j1);
+    sqlite3VdbeJumpHere(v, j2);
+  }
+  sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdx, regRecord);
+  sqlite3ReleaseTempReg(pParse, regRecord);
+  sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
+  sqlite3VdbeJumpHere(v, addr1);
+  sqlite3VdbeAddOp1(v, OP_Close, iTab);
+  sqlite3VdbeAddOp1(v, OP_Close, iIdx);
+}
+
+/*
+** Create a new index for an SQL table.  pName1.pName2 is the name of the index 
+** and pTblList is the name of the table that is to be indexed.  Both will 
+** be NULL for a primary key or an index that is created to satisfy a
+** UNIQUE constraint.  If pTable and pIndex are NULL, use pParse->pNewTable
+** as the table to be indexed.  pParse->pNewTable is a table that is
+** currently being constructed by a CREATE TABLE statement.
+**
+** pList is a list of columns to be indexed.  pList will be NULL if this
+** is a primary key or unique-constraint on the most recent column added
+** to the table currently under construction.  
+*/
+void sqlite3CreateIndex(
+  Parse *pParse,     /* All information about this parse */
+  Token *pName1,     /* First part of index name. May be NULL */
+  Token *pName2,     /* Second part of index name. May be NULL */
+  SrcList *pTblName, /* Table to index. Use pParse->pNewTable if 0 */
+  ExprList *pList,   /* A list of columns to be indexed */
+  int onError,       /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
+  Token *pStart,     /* The CREATE token that begins this statement */
+  Token *pEnd,       /* The ")" that closes the CREATE INDEX statement */
+  int sortOrder,     /* Sort order of primary key when pList==NULL */
+  int ifNotExist     /* Omit error if index already exists */
+){
+  Table *pTab = 0;     /* Table to be indexed */
+  Index *pIndex = 0;   /* The index to be created */
+  char *zName = 0;     /* Name of the index */
+  int nName;           /* Number of characters in zName */
+  int i, j;
+  Token nullId;        /* Fake token for an empty ID list */
+  DbFixer sFix;        /* For assigning database names to pTable */
+  int sortOrderMask;   /* 1 to honor DESC in index.  0 to ignore. */
+  sqlite3 *db = pParse->db;
+  Db *pDb;             /* The specific table containing the indexed database */
+  int iDb;             /* Index of the database that is being written */
+  Token *pName = 0;    /* Unqualified name of the index to create */
+  struct ExprList_item *pListItem; /* For looping over pList */
+  int nCol;
+  int nExtra = 0;
+  char *zExtra;
+
+  if( pParse->nErr || db->mallocFailed || IN_DECLARE_VTAB ){
+    goto exit_create_index;
+  }
+
+  /*
+  ** Find the table that is to be indexed.  Return early if not found.
+  */
+  if( pTblName!=0 ){
+
+    /* Use the two-part index name to determine the database 
+    ** to search for the table. 'Fix' the table name to this db
+    ** before looking up the table.
+    */
+    assert( pName1 && pName2 );
+    iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
+    if( iDb<0 ) goto exit_create_index;
+
+#ifndef SQLITE_OMIT_TEMPDB
+    /* If the index name was unqualified, check if the the table
+    ** is a temp table. If so, set the database to 1. Do not do this
+    ** if initialising a database schema.
+    */
+    if( !db->init.busy ){
+      pTab = sqlite3SrcListLookup(pParse, pTblName);
+      if( pName2 && pName2->n==0 && pTab && pTab->pSchema==db->aDb[1].pSchema ){
+        iDb = 1;
+      }
+    }
+#endif
+
+    if( sqlite3FixInit(&sFix, pParse, iDb, "index", pName) &&
+        sqlite3FixSrcList(&sFix, pTblName)
+    ){
+      /* Because the parser constructs pTblName from a single identifier,
+      ** sqlite3FixSrcList can never fail. */
+      assert(0);
+    }
+    pTab = sqlite3LocateTable(pParse, 0, pTblName->a[0].zName, 
+        pTblName->a[0].zDatabase);
+    if( !pTab ) goto exit_create_index;
+    assert( db->aDb[iDb].pSchema==pTab->pSchema );
+  }else{
+    assert( pName==0 );
+    pTab = pParse->pNewTable;
+    if( !pTab ) goto exit_create_index;
+    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+  }
+  pDb = &db->aDb[iDb];
+
+  if( pTab==0 || pParse->nErr ) goto exit_create_index;
+  if( pTab->readOnly ){
+    sqlite3ErrorMsg(pParse, "table %s may not be indexed", pTab->zName);
+    goto exit_create_index;
+  }
+#ifndef SQLITE_OMIT_VIEW
+  if( pTab->pSelect ){
+    sqlite3ErrorMsg(pParse, "views may not be indexed");
+    goto exit_create_index;
+  }
+#endif
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if( IsVirtual(pTab) ){
+    sqlite3ErrorMsg(pParse, "virtual tables may not be indexed");
+    goto exit_create_index;
+  }
+#endif
+
+  /*
+  ** Find the name of the index.  Make sure there is not already another
+  ** index or table with the same name.  
+  **
+  ** Exception:  If we are reading the names of permanent indices from the
+  ** sqlite_master table (because some other process changed the schema) and
+  ** one of the index names collides with the name of a temporary table or
+  ** index, then we will continue to process this index.
+  **
+  ** If pName==0 it means that we are
+  ** dealing with a primary key or UNIQUE constraint.  We have to invent our
+  ** own name.
+  */
+  if( pName ){
+    zName = sqlite3NameFromToken(db, pName);
+    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) goto exit_create_index;
+    if( zName==0 ) goto exit_create_index;
+    if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
+      goto exit_create_index;
+    }
+    if( !db->init.busy ){
+      if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) goto exit_create_index;
+      if( sqlite3FindTable(db, zName, 0)!=0 ){
+        sqlite3ErrorMsg(pParse, "there is already a table named %s", zName);
+        goto exit_create_index;
+      }
+    }
+    if( sqlite3FindIndex(db, zName, pDb->zName)!=0 ){
+      if( !ifNotExist ){
+        sqlite3ErrorMsg(pParse, "index %s already exists", zName);
+      }
+      goto exit_create_index;
+    }
+  }else{
+    int n;
+    Index *pLoop;
+    for(pLoop=pTab->pIndex, n=1; pLoop; pLoop=pLoop->pNext, n++){}
+    zName = sqlite3MPrintf(db, "sqlite_autoindex_%s_%d", pTab->zName, n);
+    if( zName==0 ){
+      goto exit_create_index;
+    }
+  }
+
+  /* Check for authorization to create an index.
+  */
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  {
+    const char *zDb = pDb->zName;
+    if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iDb), 0, zDb) ){
+      goto exit_create_index;
+    }
+    i = SQLITE_CREATE_INDEX;
+    if( !OMIT_TEMPDB && iDb==1 ) i = SQLITE_CREATE_TEMP_INDEX;
+    if( sqlite3AuthCheck(pParse, i, zName, pTab->zName, zDb) ){
+      goto exit_create_index;
+    }
+  }
+#endif
+
+  /* If pList==0, it means this routine was called to make a primary
+  ** key out of the last column added to the table under construction.
+  ** So create a fake list to simulate this.
+  */
+  if( pList==0 ){
+    nullId.z = (u8*)pTab->aCol[pTab->nCol-1].zName;
+    nullId.n = strlen((char*)nullId.z);
+    pList = sqlite3ExprListAppend(pParse, 0, 0, &nullId);
+    if( pList==0 ) goto exit_create_index;
+    pList->a[0].sortOrder = sortOrder;
+  }
+
+  /* Figure out how many bytes of space are required to store explicitly
+  ** specified collation sequence names.
+  */
+  for(i=0; i<pList->nExpr; i++){
+    Expr *pExpr = pList->a[i].pExpr;
+    if( pExpr ){
+      nExtra += (1 + strlen(pExpr->pColl->zName));
+    }
+  }
+
+  /* 
+  ** Allocate the index structure. 
+  */
+  nName = strlen(zName);
+  nCol = pList->nExpr;
+  pIndex = sqlite3DbMallocZero(db, 
+      sizeof(Index) +              /* Index structure  */
+      sizeof(int)*nCol +           /* Index.aiColumn   */
+      sizeof(int)*(nCol+1) +       /* Index.aiRowEst   */
+      sizeof(char *)*nCol +        /* Index.azColl     */
+      sizeof(u8)*nCol +            /* Index.aSortOrder */
+      nName + 1 +                  /* Index.zName      */
+      nExtra                       /* Collation sequence names */
+  );
+  if( db->mallocFailed ){
+    goto exit_create_index;
+  }
+  pIndex->azColl = (char**)(&pIndex[1]);
+  pIndex->aiColumn = (int *)(&pIndex->azColl[nCol]);
+  pIndex->aiRowEst = (unsigned *)(&pIndex->aiColumn[nCol]);
+  pIndex->aSortOrder = (u8 *)(&pIndex->aiRowEst[nCol+1]);
+  pIndex->zName = (char *)(&pIndex->aSortOrder[nCol]);
+  zExtra = (char *)(&pIndex->zName[nName+1]);
+  memcpy(pIndex->zName, zName, nName+1);
+  pIndex->pTable = pTab;
+  pIndex->nColumn = pList->nExpr;
+  pIndex->onError = onError;
+  pIndex->autoIndex = pName==0;
+  pIndex->pSchema = db->aDb[iDb].pSchema;
+
+  /* Check to see if we should honor DESC requests on index columns
+  */
+  if( pDb->pSchema->file_format>=4 ){
+    sortOrderMask = -1;   /* Honor DESC */
+  }else{
+    sortOrderMask = 0;    /* Ignore DESC */
+  }
+
+  /* Scan the names of the columns of the table to be indexed and
+  ** load the column indices into the Index structure.  Report an error
+  ** if any column is not found.
+  */
+  for(i=0, pListItem=pList->a; i<pList->nExpr; i++, pListItem++){
+    const char *zColName = pListItem->zName;
+    Column *pTabCol;
+    int requestedSortOrder;
+    char *zColl;                   /* Collation sequence name */
+
+    for(j=0, pTabCol=pTab->aCol; j<pTab->nCol; j++, pTabCol++){
+      if( sqlite3StrICmp(zColName, pTabCol->zName)==0 ) break;
+    }
+    if( j>=pTab->nCol ){
+      sqlite3ErrorMsg(pParse, "table %s has no column named %s",
+        pTab->zName, zColName);
+      goto exit_create_index;
+    }
+    /* TODO:  Add a test to make sure that the same column is not named
+    ** more than once within the same index.  Only the first instance of
+    ** the column will ever be used by the optimizer.  Note that using the
+    ** same column more than once cannot be an error because that would 
+    ** break backwards compatibility - it needs to be a warning.
+    */
+    pIndex->aiColumn[i] = j;
+    if( pListItem->pExpr ){
+      assert( pListItem->pExpr->pColl );
+      zColl = zExtra;
+      sqlite3_snprintf(nExtra, zExtra, "%s", pListItem->pExpr->pColl->zName);
+      zExtra += (strlen(zColl) + 1);
+    }else{
+      zColl = pTab->aCol[j].zColl;
+      if( !zColl ){
+        zColl = db->pDfltColl->zName;
+      }
+    }
+    if( !db->init.busy && !sqlite3LocateCollSeq(pParse, zColl, -1) ){
+      goto exit_create_index;
+    }
+    pIndex->azColl[i] = zColl;
+    requestedSortOrder = pListItem->sortOrder & sortOrderMask;
+    pIndex->aSortOrder[i] = requestedSortOrder;
+  }
+  sqlite3DefaultRowEst(pIndex);
+
+  if( pTab==pParse->pNewTable ){
+    /* This routine has been called to create an automatic index as a
+    ** result of a PRIMARY KEY or UNIQUE clause on a column definition, or
+    ** a PRIMARY KEY or UNIQUE clause following the column definitions.
+    ** i.e. one of:
+    **
+    ** CREATE TABLE t(x PRIMARY KEY, y);
+    ** CREATE TABLE t(x, y, UNIQUE(x, y));
+    **
+    ** Either way, check to see if the table already has such an index. If
+    ** so, don't bother creating this one. This only applies to
+    ** automatically created indices. Users can do as they wish with
+    ** explicit indices.
+    */
+    Index *pIdx;
+    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+      int k;
+      assert( pIdx->onError!=OE_None );
+      assert( pIdx->autoIndex );
+      assert( pIndex->onError!=OE_None );
+
+      if( pIdx->nColumn!=pIndex->nColumn ) continue;
+      for(k=0; k<pIdx->nColumn; k++){
+        const char *z1 = pIdx->azColl[k];
+        const char *z2 = pIndex->azColl[k];
+        if( pIdx->aiColumn[k]!=pIndex->aiColumn[k] ) break;
+        if( pIdx->aSortOrder[k]!=pIndex->aSortOrder[k] ) break;
+        if( z1!=z2 && sqlite3StrICmp(z1, z2) ) break;
+      }
+      if( k==pIdx->nColumn ){
+        if( pIdx->onError!=pIndex->onError ){
+          /* This constraint creates the same index as a previous
+          ** constraint specified somewhere in the CREATE TABLE statement.
+          ** However the ON CONFLICT clauses are different. If both this 
+          ** constraint and the previous equivalent constraint have explicit
+          ** ON CONFLICT clauses this is an error. Otherwise, use the
+          ** explicitly specified behaviour for the index.
+          */
+          if( !(pIdx->onError==OE_Default || pIndex->onError==OE_Default) ){
+            sqlite3ErrorMsg(pParse, 
+                "conflicting ON CONFLICT clauses specified", 0);
+          }
+          if( pIdx->onError==OE_Default ){
+            pIdx->onError = pIndex->onError;
+          }
+        }
+        goto exit_create_index;
+      }
+    }
+  }
+
+  /* Link the new Index structure to its table and to the other
+  ** in-memory database structures. 
+  */
+  if( db->init.busy ){
+    Index *p;
+    p = sqlite3HashInsert(&pIndex->pSchema->idxHash, 
+                         pIndex->zName, strlen(pIndex->zName)+1, pIndex);
+    if( p ){
+      assert( p==pIndex );  /* Malloc must have failed */
+      db->mallocFailed = 1;
+      goto exit_create_index;
+    }
+    db->flags |= SQLITE_InternChanges;
+    if( pTblName!=0 ){
+      pIndex->tnum = db->init.newTnum;
+    }
+  }
+
+  /* If the db->init.busy is 0 then create the index on disk.  This
+  ** involves writing the index into the master table and filling in the
+  ** index with the current table contents.
+  **
+  ** The db->init.busy is 0 when the user first enters a CREATE INDEX 
+  ** command.  db->init.busy is 1 when a database is opened and 
+  ** CREATE INDEX statements are read out of the master table.  In
+  ** the latter case the index already exists on disk, which is why
+  ** we don't want to recreate it.
+  **
+  ** If pTblName==0 it means this index is generated as a primary key
+  ** or UNIQUE constraint of a CREATE TABLE statement.  Since the table
+  ** has just been created, it contains no data and the index initialization
+  ** step can be skipped.
+  */
+  else if( db->init.busy==0 ){
+    Vdbe *v;
+    char *zStmt;
+    int iMem = ++pParse->nMem;
+
+    v = sqlite3GetVdbe(pParse);
+    if( v==0 ) goto exit_create_index;
+
+
+    /* Create the rootpage for the index
+    */
+    sqlite3BeginWriteOperation(pParse, 1, iDb);
+    sqlite3VdbeAddOp2(v, OP_CreateIndex, iDb, iMem);
+
+    /* Gather the complete text of the CREATE INDEX statement into
+    ** the zStmt variable
+    */
+    if( pStart && pEnd ){
+      /* A named index with an explicit CREATE INDEX statement */
+      zStmt = sqlite3MPrintf(db, "CREATE%s INDEX %.*s",
+        onError==OE_None ? "" : " UNIQUE",
+        pEnd->z - pName->z + 1,
+        pName->z);
+    }else{
+      /* An automatic index created by a PRIMARY KEY or UNIQUE constraint */
+      /* zStmt = sqlite3MPrintf(""); */
+      zStmt = 0;
+    }
+
+    /* Add an entry in sqlite_master for this index
+    */
+    sqlite3NestedParse(pParse, 
+        "INSERT INTO %Q.%s VALUES('index',%Q,%Q,#%d,%Q);",
+        db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
+        pIndex->zName,
+        pTab->zName,
+        iMem,
+        zStmt
+    );
+    sqlite3DbFree(db, zStmt);
+
+    /* Fill the index with data and reparse the schema. Code an OP_Expire
+    ** to invalidate all pre-compiled statements.
+    */
+    if( pTblName ){
+      sqlite3RefillIndex(pParse, pIndex, iMem);
+      sqlite3ChangeCookie(pParse, iDb);
+      sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0,
+         sqlite3MPrintf(db, "name='%q'", pIndex->zName), P4_DYNAMIC);
+      sqlite3VdbeAddOp1(v, OP_Expire, 0);
+    }
+  }
+
+  /* When adding an index to the list of indices for a table, make
+  ** sure all indices labeled OE_Replace come after all those labeled
+  ** OE_Ignore.  This is necessary for the correct operation of UPDATE
+  ** and INSERT.
+  */
+  if( db->init.busy || pTblName==0 ){
+    if( onError!=OE_Replace || pTab->pIndex==0
+         || pTab->pIndex->onError==OE_Replace){
+      pIndex->pNext = pTab->pIndex;
+      pTab->pIndex = pIndex;
+    }else{
+      Index *pOther = pTab->pIndex;
+      while( pOther->pNext && pOther->pNext->onError!=OE_Replace ){
+        pOther = pOther->pNext;
+      }
+      pIndex->pNext = pOther->pNext;
+      pOther->pNext = pIndex;
+    }
+    pIndex = 0;
+  }
+
+  /* Clean up before exiting */
+exit_create_index:
+  if( pIndex ){
+    freeIndex(pIndex);
+  }
+  sqlite3ExprListDelete(db, pList);
+  sqlite3SrcListDelete(db, pTblName);
+  sqlite3DbFree(db, zName);
+  return;
+}
+
+/*
+** Generate code to make sure the file format number is at least minFormat.
+** The generated code will increase the file format number if necessary.
+*/
+void sqlite3MinimumFileFormat(Parse *pParse, int iDb, int minFormat){
+  Vdbe *v;
+  v = sqlite3GetVdbe(pParse);
+  if( v ){
+    int r1 = sqlite3GetTempReg(pParse);
+    int r2 = sqlite3GetTempReg(pParse);
+    int j1;
+    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, r1, 1);
+    sqlite3VdbeUsesBtree(v, iDb);
+    sqlite3VdbeAddOp2(v, OP_Integer, minFormat, r2);
+    j1 = sqlite3VdbeAddOp3(v, OP_Ge, r2, 0, r1);
+    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, 1, r2);
+    sqlite3VdbeJumpHere(v, j1);
+    sqlite3ReleaseTempReg(pParse, r1);
+    sqlite3ReleaseTempReg(pParse, r2);
+  }
+}
+
+/*
+** Fill the Index.aiRowEst[] array with default information - information
+** to be used when we have not run the ANALYZE command.
+**
+** aiRowEst[0] is suppose to contain the number of elements in the index.
+** Since we do not know, guess 1 million.  aiRowEst[1] is an estimate of the
+** number of rows in the table that match any particular value of the
+** first column of the index.  aiRowEst[2] is an estimate of the number
+** of rows that match any particular combiniation of the first 2 columns
+** of the index.  And so forth.  It must always be the case that
+*
+**           aiRowEst[N]<=aiRowEst[N-1]
+**           aiRowEst[N]>=1
+**
+** Apart from that, we have little to go on besides intuition as to
+** how aiRowEst[] should be initialized.  The numbers generated here
+** are based on typical values found in actual indices.
+*/
+void sqlite3DefaultRowEst(Index *pIdx){
+  unsigned *a = pIdx->aiRowEst;
+  int i;
+  assert( a!=0 );
+  a[0] = 1000000;
+  for(i=pIdx->nColumn; i>=5; i--){
+    a[i] = 5;
+  }
+  while( i>=1 ){
+    a[i] = 11 - i;
+    i--;
+  }
+  if( pIdx->onError!=OE_None ){
+    a[pIdx->nColumn] = 1;
+  }
+}
+
+/*
+** This routine will drop an existing named index.  This routine
+** implements the DROP INDEX statement.
+*/
+void sqlite3DropIndex(Parse *pParse, SrcList *pName, int ifExists){
+  Index *pIndex;
+  Vdbe *v;
+  sqlite3 *db = pParse->db;
+  int iDb;
+
+  if( pParse->nErr || db->mallocFailed ){
+    goto exit_drop_index;
+  }
+  assert( pName->nSrc==1 );
+  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
+    goto exit_drop_index;
+  }
+  pIndex = sqlite3FindIndex(db, pName->a[0].zName, pName->a[0].zDatabase);
+  if( pIndex==0 ){
+    if( !ifExists ){
+      sqlite3ErrorMsg(pParse, "no such index: %S", pName, 0);
+    }
+    pParse->checkSchema = 1;
+    goto exit_drop_index;
+  }
+  if( pIndex->autoIndex ){
+    sqlite3ErrorMsg(pParse, "index associated with UNIQUE "
+      "or PRIMARY KEY constraint cannot be dropped", 0);
+    goto exit_drop_index;
+  }
+  iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  {
+    int code = SQLITE_DROP_INDEX;
+    Table *pTab = pIndex->pTable;
+    const char *zDb = db->aDb[iDb].zName;
+    const char *zTab = SCHEMA_TABLE(iDb);
+    if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
+      goto exit_drop_index;
+    }
+    if( !OMIT_TEMPDB && iDb ) code = SQLITE_DROP_TEMP_INDEX;
+    if( sqlite3AuthCheck(pParse, code, pIndex->zName, pTab->zName, zDb) ){
+      goto exit_drop_index;
+    }
+  }
+#endif
+
+  /* Generate code to remove the index and from the master table */
+  v = sqlite3GetVdbe(pParse);
+  if( v ){
+    sqlite3BeginWriteOperation(pParse, 1, iDb);
+    sqlite3NestedParse(pParse,
+       "DELETE FROM %Q.%s WHERE name=%Q",
+       db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
+       pIndex->zName
+    );
+    if( sqlite3FindTable(db, "sqlite_stat1", db->aDb[iDb].zName) ){
+      sqlite3NestedParse(pParse,
+        "DELETE FROM %Q.sqlite_stat1 WHERE idx=%Q",
+        db->aDb[iDb].zName, pIndex->zName
+      );
+    }
+    sqlite3ChangeCookie(pParse, iDb);
+    destroyRootPage(pParse, pIndex->tnum, iDb);
+    sqlite3VdbeAddOp4(v, OP_DropIndex, iDb, 0, 0, pIndex->zName, 0);
+  }
+
+exit_drop_index:
+  sqlite3SrcListDelete(db, pName);
+}
+
+/*
+** pArray is a pointer to an array of objects.  Each object in the
+** array is szEntry bytes in size.  This routine allocates a new
+** object on the end of the array.
+**
+** *pnEntry is the number of entries already in use.  *pnAlloc is
+** the previously allocated size of the array.  initSize is the
+** suggested initial array size allocation.
+**
+** The index of the new entry is returned in *pIdx.
+**
+** This routine returns a pointer to the array of objects.  This
+** might be the same as the pArray parameter or it might be a different
+** pointer if the array was resized.
+*/
+void *sqlite3ArrayAllocate(
+  sqlite3 *db,      /* Connection to notify of malloc failures */
+  void *pArray,     /* Array of objects.  Might be reallocated */
+  int szEntry,      /* Size of each object in the array */
+  int initSize,     /* Suggested initial allocation, in elements */
+  int *pnEntry,     /* Number of objects currently in use */
+  int *pnAlloc,     /* Current size of the allocation, in elements */
+  int *pIdx         /* Write the index of a new slot here */
+){
+  char *z;
+  if( *pnEntry >= *pnAlloc ){
+    void *pNew;
+    int newSize;
+    newSize = (*pnAlloc)*2 + initSize;
+    pNew = sqlite3DbRealloc(db, pArray, newSize*szEntry);
+    if( pNew==0 ){
+      *pIdx = -1;
+      return pArray;
+    }
+    *pnAlloc = newSize;
+    pArray = pNew;
+  }
+  z = (char*)pArray;
+  memset(&z[*pnEntry * szEntry], 0, szEntry);
+  *pIdx = *pnEntry;
+  ++*pnEntry;
+  return pArray;
+}
+
+/*
+** Append a new element to the given IdList.  Create a new IdList if
+** need be.
+**
+** A new IdList is returned, or NULL if malloc() fails.
+*/
+IdList *sqlite3IdListAppend(sqlite3 *db, IdList *pList, Token *pToken){
+  int i;
+  if( pList==0 ){
+    pList = sqlite3DbMallocZero(db, sizeof(IdList) );
+    if( pList==0 ) return 0;
+    pList->nAlloc = 0;
+  }
+  pList->a = sqlite3ArrayAllocate(
+      db,
+      pList->a,
+      sizeof(pList->a[0]),
+      5,
+      &pList->nId,
+      &pList->nAlloc,
+      &i
+  );
+  if( i<0 ){
+    sqlite3IdListDelete(db, pList);
+    return 0;
+  }
+  pList->a[i].zName = sqlite3NameFromToken(db, pToken);
+  return pList;
+}
+
+/*
+** Delete an IdList.
+*/
+void sqlite3IdListDelete(sqlite3 *db, IdList *pList){
+  int i;
+  if( pList==0 ) return;
+  for(i=0; i<pList->nId; i++){
+    sqlite3DbFree(db, pList->a[i].zName);
+  }
+  sqlite3DbFree(db, pList->a);
+  sqlite3DbFree(db, pList);
+}
+
+/*
+** Return the index in pList of the identifier named zId.  Return -1
+** if not found.
+*/
+int sqlite3IdListIndex(IdList *pList, const char *zName){
+  int i;
+  if( pList==0 ) return -1;
+  for(i=0; i<pList->nId; i++){
+    if( sqlite3StrICmp(pList->a[i].zName, zName)==0 ) return i;
+  }
+  return -1;
+}
+
+/*
+** Append a new table name to the given SrcList.  Create a new SrcList if
+** need be.  A new entry is created in the SrcList even if pToken is NULL.
+**
+** A new SrcList is returned, or NULL if malloc() fails.
+**
+** If pDatabase is not null, it means that the table has an optional
+** database name prefix.  Like this:  "database.table".  The pDatabase
+** points to the table name and the pTable points to the database name.
+** The SrcList.a[].zName field is filled with the table name which might
+** come from pTable (if pDatabase is NULL) or from pDatabase.  
+** SrcList.a[].zDatabase is filled with the database name from pTable,
+** or with NULL if no database is specified.
+**
+** In other words, if call like this:
+**
+**         sqlite3SrcListAppend(D,A,B,0);
+**
+** Then B is a table name and the database name is unspecified.  If called
+** like this:
+**
+**         sqlite3SrcListAppend(D,A,B,C);
+**
+** Then C is the table name and B is the database name.
+*/
+SrcList *sqlite3SrcListAppend(
+  sqlite3 *db,        /* Connection to notify of malloc failures */
+  SrcList *pList,     /* Append to this SrcList. NULL creates a new SrcList */
+  Token *pTable,      /* Table to append */
+  Token *pDatabase    /* Database of the table */
+){
+  struct SrcList_item *pItem;
+  if( pList==0 ){
+    pList = sqlite3DbMallocZero(db, sizeof(SrcList) );
+    if( pList==0 ) return 0;
+    pList->nAlloc = 1;
+  }
+  if( pList->nSrc>=pList->nAlloc ){
+    SrcList *pNew;
+    pList->nAlloc *= 2;
+    pNew = sqlite3DbRealloc(db, pList,
+               sizeof(*pList) + (pList->nAlloc-1)*sizeof(pList->a[0]) );
+    if( pNew==0 ){
+      sqlite3SrcListDelete(db, pList);
+      return 0;
+    }
+    pList = pNew;
+  }
+  pItem = &pList->a[pList->nSrc];
+  memset(pItem, 0, sizeof(pList->a[0]));
+  if( pDatabase && pDatabase->z==0 ){
+    pDatabase = 0;
+  }
+  if( pDatabase && pTable ){
+    Token *pTemp = pDatabase;
+    pDatabase = pTable;
+    pTable = pTemp;
+  }
+  pItem->zName = sqlite3NameFromToken(db, pTable);
+  pItem->zDatabase = sqlite3NameFromToken(db, pDatabase);
+  pItem->iCursor = -1;
+  pItem->isPopulated = 0;
+  pList->nSrc++;
+  return pList;
+}
+
+/*
+** Assign cursors to all tables in a SrcList
+*/
+void sqlite3SrcListAssignCursors(Parse *pParse, SrcList *pList){
+  int i;
+  struct SrcList_item *pItem;
+  assert(pList || pParse->db->mallocFailed );
+  if( pList ){
+    for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
+      if( pItem->iCursor>=0 ) break;
+      pItem->iCursor = pParse->nTab++;
+      if( pItem->pSelect ){
+        sqlite3SrcListAssignCursors(pParse, pItem->pSelect->pSrc);
+      }
+    }
+  }
+}
+
+/*
+** Delete an entire SrcList including all its substructure.
+*/
+void sqlite3SrcListDelete(sqlite3 *db, SrcList *pList){
+  int i;
+  struct SrcList_item *pItem;
+  if( pList==0 ) return;
+  for(pItem=pList->a, i=0; i<pList->nSrc; i++, pItem++){
+    sqlite3DbFree(db, pItem->zDatabase);
+    sqlite3DbFree(db, pItem->zName);
+    sqlite3DbFree(db, pItem->zAlias);
+    sqlite3DeleteTable(pItem->pTab);
+    sqlite3SelectDelete(db, pItem->pSelect);
+    sqlite3ExprDelete(db, pItem->pOn);
+    sqlite3IdListDelete(db, pItem->pUsing);
+  }
+  sqlite3DbFree(db, pList);
+}
+
+/*
+** This routine is called by the parser to add a new term to the
+** end of a growing FROM clause.  The "p" parameter is the part of
+** the FROM clause that has already been constructed.  "p" is NULL
+** if this is the first term of the FROM clause.  pTable and pDatabase
+** are the name of the table and database named in the FROM clause term.
+** pDatabase is NULL if the database name qualifier is missing - the
+** usual case.  If the term has a alias, then pAlias points to the
+** alias token.  If the term is a subquery, then pSubquery is the
+** SELECT statement that the subquery encodes.  The pTable and
+** pDatabase parameters are NULL for subqueries.  The pOn and pUsing
+** parameters are the content of the ON and USING clauses.
+**
+** Return a new SrcList which encodes is the FROM with the new
+** term added.
+*/
+SrcList *sqlite3SrcListAppendFromTerm(
+  Parse *pParse,          /* Parsing context */
+  SrcList *p,             /* The left part of the FROM clause already seen */
+  Token *pTable,          /* Name of the table to add to the FROM clause */
+  Token *pDatabase,       /* Name of the database containing pTable */
+  Token *pAlias,          /* The right-hand side of the AS subexpression */
+  Select *pSubquery,      /* A subquery used in place of a table name */
+  Expr *pOn,              /* The ON clause of a join */
+  IdList *pUsing          /* The USING clause of a join */
+){
+  struct SrcList_item *pItem;
+  sqlite3 *db = pParse->db;
+  p = sqlite3SrcListAppend(db, p, pTable, pDatabase);
+  if( p==0 || p->nSrc==0 ){
+    sqlite3ExprDelete(db, pOn);
+    sqlite3IdListDelete(db, pUsing);
+    sqlite3SelectDelete(db, pSubquery);
+    return p;
+  }
+  pItem = &p->a[p->nSrc-1];
+  if( pAlias && pAlias->n ){
+    pItem->zAlias = sqlite3NameFromToken(db, pAlias);
+  }
+  pItem->pSelect = pSubquery;
+  pItem->pOn = pOn;
+  pItem->pUsing = pUsing;
+  return p;
+}
+
+/*
+** When building up a FROM clause in the parser, the join operator
+** is initially attached to the left operand.  But the code generator
+** expects the join operator to be on the right operand.  This routine
+** Shifts all join operators from left to right for an entire FROM
+** clause.
+**
+** Example: Suppose the join is like this:
+**
+**           A natural cross join B
+**
+** The operator is "natural cross join".  The A and B operands are stored
+** in p->a[0] and p->a[1], respectively.  The parser initially stores the
+** operator with A.  This routine shifts that operator over to B.
+*/
+void sqlite3SrcListShiftJoinType(SrcList *p){
+  if( p && p->a ){
+    int i;
+    for(i=p->nSrc-1; i>0; i--){
+      p->a[i].jointype = p->a[i-1].jointype;
+    }
+    p->a[0].jointype = 0;
+  }
+}
+
+/*
+** Begin a transaction
+*/
+void sqlite3BeginTransaction(Parse *pParse, int type){
+  sqlite3 *db;
+  Vdbe *v;
+  int i;
+
+  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
+  if( pParse->nErr || db->mallocFailed ) return;
+  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ) return;
+
+  v = sqlite3GetVdbe(pParse);
+  if( !v ) return;
+  if( type!=TK_DEFERRED ){
+    for(i=0; i<db->nDb; i++){
+      sqlite3VdbeAddOp2(v, OP_Transaction, i, (type==TK_EXCLUSIVE)+1);
+      sqlite3VdbeUsesBtree(v, i);
+    }
+  }
+  sqlite3VdbeAddOp2(v, OP_AutoCommit, 0, 0);
+}
+
+/*
+** Commit a transaction
+*/
+void sqlite3CommitTransaction(Parse *pParse){
+  sqlite3 *db;
+  Vdbe *v;
+
+  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
+  if( pParse->nErr || db->mallocFailed ) return;
+  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "COMMIT", 0, 0) ) return;
+
+  v = sqlite3GetVdbe(pParse);
+  if( v ){
+    sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, 0);
+  }
+}
+
+/*
+** Rollback a transaction
+*/
+void sqlite3RollbackTransaction(Parse *pParse){
+  sqlite3 *db;
+  Vdbe *v;
+
+  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
+  if( pParse->nErr || db->mallocFailed ) return;
+  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "ROLLBACK", 0, 0) ) return;
+
+  v = sqlite3GetVdbe(pParse);
+  if( v ){
+    sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, 1);
+  }
+}
+
+/*
+** Make sure the TEMP database is open and available for use.  Return
+** the number of errors.  Leave any error messages in the pParse structure.
+*/
+int sqlite3OpenTempDatabase(Parse *pParse){
+  sqlite3 *db = pParse->db;
+  if( db->aDb[1].pBt==0 && !pParse->explain ){
+    int rc;
+    static const int flags = 
+          SQLITE_OPEN_READWRITE |
+          SQLITE_OPEN_CREATE |
+          SQLITE_OPEN_EXCLUSIVE |
+          SQLITE_OPEN_DELETEONCLOSE |
+          SQLITE_OPEN_TEMP_DB;
+
+    rc = sqlite3BtreeFactory(db, 0, 0, SQLITE_DEFAULT_CACHE_SIZE, flags,
+                                 &db->aDb[1].pBt);
+    if( rc!=SQLITE_OK ){
+      sqlite3ErrorMsg(pParse, "unable to open a temporary database "
+        "file for storing temporary tables");
+      pParse->rc = rc;
+      return 1;
+    }
+    assert( (db->flags & SQLITE_InTrans)==0 || db->autoCommit );
+    assert( db->aDb[1].pSchema );
+    sqlite3PagerJournalMode(sqlite3BtreePager(db->aDb[1].pBt),
+                            db->dfltJournalMode);
+  }
+  return 0;
+}
+
+/*
+** Generate VDBE code that will verify the schema cookie and start
+** a read-transaction for all named database files.
+**
+** It is important that all schema cookies be verified and all
+** read transactions be started before anything else happens in
+** the VDBE program.  But this routine can be called after much other
+** code has been generated.  So here is what we do:
+**
+** The first time this routine is called, we code an OP_Goto that
+** will jump to a subroutine at the end of the program.  Then we
+** record every database that needs its schema verified in the
+** pParse->cookieMask field.  Later, after all other code has been
+** generated, the subroutine that does the cookie verifications and
+** starts the transactions will be coded and the OP_Goto P2 value
+** will be made to point to that subroutine.  The generation of the
+** cookie verification subroutine code happens in sqlite3FinishCoding().
+**
+** If iDb<0 then code the OP_Goto only - don't set flag to verify the
+** schema on any databases.  This can be used to position the OP_Goto
+** early in the code, before we know if any database tables will be used.
+*/
+void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
+  sqlite3 *db;
+  Vdbe *v;
+  int mask;
+
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 ) return;  /* This only happens if there was a prior error */
+  db = pParse->db;
+  if( pParse->cookieGoto==0 ){
+    pParse->cookieGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0)+1;
+  }
+  if( iDb>=0 ){
+    assert( iDb<db->nDb );
+    assert( db->aDb[iDb].pBt!=0 || iDb==1 );
+    assert( iDb<SQLITE_MAX_ATTACHED+2 );
+    mask = 1<<iDb;
+    if( (pParse->cookieMask & mask)==0 ){
+      pParse->cookieMask |= mask;
+      pParse->cookieValue[iDb] = db->aDb[iDb].pSchema->schema_cookie;
+      if( !OMIT_TEMPDB && iDb==1 ){
+        sqlite3OpenTempDatabase(pParse);
+      }
+    }
+  }
+}
+
+/*
+** Generate VDBE code that prepares for doing an operation that
+** might change the database.
+**
+** This routine starts a new transaction if we are not already within
+** a transaction.  If we are already within a transaction, then a checkpoint
+** is set if the setStatement parameter is true.  A checkpoint should
+** be set for operations that might fail (due to a constraint) part of
+** the way through and which will need to undo some writes without having to
+** rollback the whole transaction.  For operations where all constraints
+** can be checked before any changes are made to the database, it is never
+** necessary to undo a write and the checkpoint should not be set.
+**
+** Only database iDb and the temp database are made writable by this call.
+** If iDb==0, then the main and temp databases are made writable.   If
+** iDb==1 then only the temp database is made writable.  If iDb>1 then the
+** specified auxiliary database and the temp database are made writable.
+*/
+void sqlite3BeginWriteOperation(Parse *pParse, int setStatement, int iDb){
+  Vdbe *v = sqlite3GetVdbe(pParse);
+  if( v==0 ) return;
+  sqlite3CodeVerifySchema(pParse, iDb);
+  pParse->writeMask |= 1<<iDb;
+  if( setStatement && pParse->nested==0 ){
+    sqlite3VdbeAddOp1(v, OP_Statement, iDb);
+  }
+  if( (OMIT_TEMPDB || iDb!=1) && pParse->db->aDb[1].pBt!=0 ){
+    sqlite3BeginWriteOperation(pParse, setStatement, 1);
+  }
+}
+
+/*
+** Check to see if pIndex uses the collating sequence pColl.  Return
+** true if it does and false if it does not.
+*/
+#ifndef SQLITE_OMIT_REINDEX
+static int collationMatch(const char *zColl, Index *pIndex){
+  int i;
+  for(i=0; i<pIndex->nColumn; i++){
+    const char *z = pIndex->azColl[i];
+    if( z==zColl || (z && zColl && 0==sqlite3StrICmp(z, zColl)) ){
+      return 1;
+    }
+  }
+  return 0;
+}
+#endif
+
+/*
+** Recompute all indices of pTab that use the collating sequence pColl.
+** If pColl==0 then recompute all indices of pTab.
+*/
+#ifndef SQLITE_OMIT_REINDEX
+static void reindexTable(Parse *pParse, Table *pTab, char const *zColl){
+  Index *pIndex;              /* An index associated with pTab */
+
+  for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
+    if( zColl==0 || collationMatch(zColl, pIndex) ){
+      int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+      sqlite3BeginWriteOperation(pParse, 0, iDb);
+      sqlite3RefillIndex(pParse, pIndex, -1);
+    }
+  }
+}
+#endif
+
+/*
+** Recompute all indices of all tables in all databases where the
+** indices use the collating sequence pColl.  If pColl==0 then recompute
+** all indices everywhere.
+*/
+#ifndef SQLITE_OMIT_REINDEX
+static void reindexDatabases(Parse *pParse, char const *zColl){
+  Db *pDb;                    /* A single database */
+  int iDb;                    /* The database index number */
+  sqlite3 *db = pParse->db;   /* The database connection */
+  HashElem *k;                /* For looping over tables in pDb */
+  Table *pTab;                /* A table in the database */
+
+  for(iDb=0, pDb=db->aDb; iDb<db->nDb; iDb++, pDb++){
+    assert( pDb!=0 );
+    for(k=sqliteHashFirst(&pDb->pSchema->tblHash);  k; k=sqliteHashNext(k)){
+      pTab = (Table*)sqliteHashData(k);
+      reindexTable(pParse, pTab, zColl);
+    }
+  }
+}
+#endif
+
+/*
+** Generate code for the REINDEX command.
+**
+**        REINDEX                            -- 1
+**        REINDEX  <collation>               -- 2
+**        REINDEX  ?<database>.?<tablename>  -- 3
+**        REINDEX  ?<database>.?<indexname>  -- 4
+**
+** Form 1 causes all indices in all attached databases to be rebuilt.
+** Form 2 rebuilds all indices in all databases that use the named
+** collating function.  Forms 3 and 4 rebuild the named index or all
+** indices associated with the named table.
+*/
+#ifndef SQLITE_OMIT_REINDEX
+void sqlite3Reindex(Parse *pParse, Token *pName1, Token *pName2){
+  CollSeq *pColl;             /* Collating sequence to be reindexed, or NULL */
+  char *z;                    /* Name of a table or index */
+  const char *zDb;            /* Name of the database */
+  Table *pTab;                /* A table in the database */
+  Index *pIndex;              /* An index associated with pTab */
+  int iDb;                    /* The database index number */
+  sqlite3 *db = pParse->db;   /* The database connection */
+  Token *pObjName;            /* Name of the table or index to be reindexed */
+
+  /* Read the database schema. If an error occurs, leave an error message
+  ** and code in pParse and return NULL. */
+  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
+    return;
+  }
+
+  if( pName1==0 || pName1->z==0 ){
+    reindexDatabases(pParse, 0);
+    return;
+  }else if( pName2==0 || pName2->z==0 ){
+    char *zColl;
+    assert( pName1->z );
+    zColl = sqlite3NameFromToken(pParse->db, pName1);
+    if( !zColl ) return;
+    pColl = sqlite3FindCollSeq(db, ENC(db), zColl, -1, 0);
+    if( pColl ){
+      if( zColl ){
+        reindexDatabases(pParse, zColl);
+        sqlite3DbFree(db, zColl);
+      }
+      return;
+    }
+    sqlite3DbFree(db, zColl);
+  }
+  iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pObjName);
+  if( iDb<0 ) return;
+  z = sqlite3NameFromToken(db, pObjName);
+  if( z==0 ) return;
+  zDb = db->aDb[iDb].zName;
+  pTab = sqlite3FindTable(db, z, zDb);
+  if( pTab ){
+    reindexTable(pParse, pTab, 0);
+    sqlite3DbFree(db, z);
+    return;
+  }
+  pIndex = sqlite3FindIndex(db, z, zDb);
+  sqlite3DbFree(db, z);
+  if( pIndex ){
+    sqlite3BeginWriteOperation(pParse, 0, iDb);
+    sqlite3RefillIndex(pParse, pIndex, -1);
+    return;
+  }
+  sqlite3ErrorMsg(pParse, "unable to identify the object to be reindexed");
+}
+#endif
+
+/*
+** Return a dynamicly allocated KeyInfo structure that can be used
+** with OP_OpenRead or OP_OpenWrite to access database index pIdx.
+**
+** If successful, a pointer to the new structure is returned. In this case
+** the caller is responsible for calling sqlite3DbFree(db, ) on the returned 
+** pointer. If an error occurs (out of memory or missing collation 
+** sequence), NULL is returned and the state of pParse updated to reflect
+** the error.
+*/
+KeyInfo *sqlite3IndexKeyinfo(Parse *pParse, Index *pIdx){
+  int i;
+  int nCol = pIdx->nColumn;
+  int nBytes = sizeof(KeyInfo) + (nCol-1)*sizeof(CollSeq*) + nCol;
+  sqlite3 *db = pParse->db;
+  KeyInfo *pKey = (KeyInfo *)sqlite3DbMallocZero(db, nBytes);
+
+  if( pKey ){
+    pKey->db = pParse->db;
+    pKey->aSortOrder = (u8 *)&(pKey->aColl[nCol]);
+    assert( &pKey->aSortOrder[nCol]==&(((u8 *)pKey)[nBytes]) );
+    for(i=0; i<nCol; i++){
+      char *zColl = pIdx->azColl[i];
+      assert( zColl );
+      pKey->aColl[i] = sqlite3LocateCollSeq(pParse, zColl, -1);
+      pKey->aSortOrder[i] = pIdx->aSortOrder[i];
+    }
+    pKey->nField = nCol;
+  }
+
+  if( pParse->nErr ){
+    sqlite3DbFree(db, pKey);
+    pKey = 0;
+  }
+  return pKey;
+}
+
+/* Begin preload-cache.patch for Chromium */
+/* See declaration in sqlite3.h for information */
+int sqlite3Preload(sqlite3 *db)
+{
+  Pager *pPager;
+  Btree *pBt;
+  int rc;
+  int i;
+  int dbsLoaded = 0;
+
+  for(i=0; i<db->nDb; i++) {
+    pBt = db->aDb[i].pBt;
+    if( !pBt )
+      continue;
+    pPager = sqlite3BtreePager(pBt);
+    if( pPager ) {
+      rc = sqlite3PagerLoadall(pPager);
+      if (rc == SQLITE_OK)
+        dbsLoaded++;
+    }
+  }
+  if (dbsLoaded == 0)
+    return SQLITE_ERROR;
+  return SQLITE_OK;
+}
+/* End preload-cache.patch for Chromium */
diff --git a/third_party/sqlite/src/callback.c b/third_party/sqlite/src/callback.c
new file mode 100755
index 0000000..a77f994
--- /dev/null
+++ b/third_party/sqlite/src/callback.c
@@ -0,0 +1,380 @@
+/*
+** 2005 May 23 
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains functions used to access the internal hash tables
+** of user defined functions and collation sequences.
+**
+** $Id: callback.c,v 1.26 2008/07/28 19:34:53 drh Exp $
+*/
+
+#include "sqliteInt.h"
+
+/*
+** Invoke the 'collation needed' callback to request a collation sequence
+** in the database text encoding of name zName, length nName.
+** If the collation sequence
+*/
+static void callCollNeeded(sqlite3 *db, const char *zName, int nName){
+  assert( !db->xCollNeeded || !db->xCollNeeded16 );
+  if( nName<0 ) nName = sqlite3Strlen(db, zName);
+  if( db->xCollNeeded ){
+    char *zExternal = sqlite3DbStrNDup(db, zName, nName);
+    if( !zExternal ) return;
+    db->xCollNeeded(db->pCollNeededArg, db, (int)ENC(db), zExternal);
+    sqlite3DbFree(db, zExternal);
+  }
+#ifndef SQLITE_OMIT_UTF16
+  if( db->xCollNeeded16 ){
+    char const *zExternal;
+    sqlite3_value *pTmp = sqlite3ValueNew(db);
+    sqlite3ValueSetStr(pTmp, nName, zName, SQLITE_UTF8, SQLITE_STATIC);
+    zExternal = sqlite3ValueText(pTmp, SQLITE_UTF16NATIVE);
+    if( zExternal ){
+      db->xCollNeeded16(db->pCollNeededArg, db, (int)ENC(db), zExternal);
+    }
+    sqlite3ValueFree(pTmp);
+  }
+#endif
+}
+
+/*
+** This routine is called if the collation factory fails to deliver a
+** collation function in the best encoding but there may be other versions
+** of this collation function (for other text encodings) available. Use one
+** of these instead if they exist. Avoid a UTF-8 <-> UTF-16 conversion if
+** possible.
+*/
+static int synthCollSeq(sqlite3 *db, CollSeq *pColl){
+  CollSeq *pColl2;
+  char *z = pColl->zName;
+  int n = strlen(z);
+  int i;
+  static const u8 aEnc[] = { SQLITE_UTF16BE, SQLITE_UTF16LE, SQLITE_UTF8 };
+  for(i=0; i<3; i++){
+    pColl2 = sqlite3FindCollSeq(db, aEnc[i], z, n, 0);
+    if( pColl2->xCmp!=0 ){
+      memcpy(pColl, pColl2, sizeof(CollSeq));
+      pColl->xDel = 0;         /* Do not copy the destructor */
+      return SQLITE_OK;
+    }
+  }
+  return SQLITE_ERROR;
+}
+
+/*
+** This function is responsible for invoking the collation factory callback
+** or substituting a collation sequence of a different encoding when the
+** requested collation sequence is not available in the database native
+** encoding.
+** 
+** If it is not NULL, then pColl must point to the database native encoding 
+** collation sequence with name zName, length nName.
+**
+** The return value is either the collation sequence to be used in database
+** db for collation type name zName, length nName, or NULL, if no collation
+** sequence can be found.
+*/
+CollSeq *sqlite3GetCollSeq(
+  sqlite3* db, 
+  CollSeq *pColl, 
+  const char *zName, 
+  int nName
+){
+  CollSeq *p;
+
+  p = pColl;
+  if( !p ){
+    p = sqlite3FindCollSeq(db, ENC(db), zName, nName, 0);
+  }
+  if( !p || !p->xCmp ){
+    /* No collation sequence of this type for this encoding is registered.
+    ** Call the collation factory to see if it can supply us with one.
+    */
+    callCollNeeded(db, zName, nName);
+    p = sqlite3FindCollSeq(db, ENC(db), zName, nName, 0);
+  }
+  if( p && !p->xCmp && synthCollSeq(db, p) ){
+    p = 0;
+  }
+  assert( !p || p->xCmp );
+  return p;
+}
+
+/*
+** This routine is called on a collation sequence before it is used to
+** check that it is defined. An undefined collation sequence exists when
+** a database is loaded that contains references to collation sequences
+** that have not been defined by sqlite3_create_collation() etc.
+**
+** If required, this routine calls the 'collation needed' callback to
+** request a definition of the collating sequence. If this doesn't work, 
+** an equivalent collating sequence that uses a text encoding different
+** from the main database is substituted, if one is available.
+*/
+int sqlite3CheckCollSeq(Parse *pParse, CollSeq *pColl){
+  if( pColl ){
+    const char *zName = pColl->zName;
+    CollSeq *p = sqlite3GetCollSeq(pParse->db, pColl, zName, -1);
+    if( !p ){
+      if( pParse->nErr==0 ){
+        sqlite3ErrorMsg(pParse, "no such collation sequence: %s", zName);
+      }
+      pParse->nErr++;
+      return SQLITE_ERROR;
+    }
+    assert( p==pColl );
+  }
+  return SQLITE_OK;
+}
+
+
+
+/*
+** Locate and return an entry from the db.aCollSeq hash table. If the entry
+** specified by zName and nName is not found and parameter 'create' is
+** true, then create a new entry. Otherwise return NULL.
+**
+** Each pointer stored in the sqlite3.aCollSeq hash table contains an
+** array of three CollSeq structures. The first is the collation sequence
+** prefferred for UTF-8, the second UTF-16le, and the third UTF-16be.
+**
+** Stored immediately after the three collation sequences is a copy of
+** the collation sequence name. A pointer to this string is stored in
+** each collation sequence structure.
+*/
+static CollSeq *findCollSeqEntry(
+  sqlite3 *db,
+  const char *zName,
+  int nName,
+  int create
+){
+  CollSeq *pColl;
+  if( nName<0 ) nName = sqlite3Strlen(db, zName);
+  pColl = sqlite3HashFind(&db->aCollSeq, zName, nName);
+
+  if( 0==pColl && create ){
+    pColl = sqlite3DbMallocZero(db, 3*sizeof(*pColl) + nName + 1 );
+    if( pColl ){
+      CollSeq *pDel = 0;
+      pColl[0].zName = (char*)&pColl[3];
+      pColl[0].enc = SQLITE_UTF8;
+      pColl[1].zName = (char*)&pColl[3];
+      pColl[1].enc = SQLITE_UTF16LE;
+      pColl[2].zName = (char*)&pColl[3];
+      pColl[2].enc = SQLITE_UTF16BE;
+      memcpy(pColl[0].zName, zName, nName);
+      pColl[0].zName[nName] = 0;
+      pDel = sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, nName, pColl);
+
+      /* If a malloc() failure occured in sqlite3HashInsert(), it will 
+      ** return the pColl pointer to be deleted (because it wasn't added
+      ** to the hash table).
+      */
+      assert( pDel==0 || pDel==pColl );
+      if( pDel!=0 ){
+        db->mallocFailed = 1;
+        sqlite3DbFree(db, pDel);
+        pColl = 0;
+      }
+    }
+  }
+  return pColl;
+}
+
+/*
+** Parameter zName points to a UTF-8 encoded string nName bytes long.
+** Return the CollSeq* pointer for the collation sequence named zName
+** for the encoding 'enc' from the database 'db'.
+**
+** If the entry specified is not found and 'create' is true, then create a
+** new entry.  Otherwise return NULL.
+**
+** A separate function sqlite3LocateCollSeq() is a wrapper around
+** this routine.  sqlite3LocateCollSeq() invokes the collation factory
+** if necessary and generates an error message if the collating sequence
+** cannot be found.
+*/
+CollSeq *sqlite3FindCollSeq(
+  sqlite3 *db,
+  u8 enc,
+  const char *zName,
+  int nName,
+  int create
+){
+  CollSeq *pColl;
+  if( zName ){
+    pColl = findCollSeqEntry(db, zName, nName, create);
+  }else{
+    pColl = db->pDfltColl;
+  }
+  assert( SQLITE_UTF8==1 && SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
+  assert( enc>=SQLITE_UTF8 && enc<=SQLITE_UTF16BE );
+  if( pColl ) pColl += enc-1;
+  return pColl;
+}
+
+/*
+** Locate a user function given a name, a number of arguments and a flag
+** indicating whether the function prefers UTF-16 over UTF-8.  Return a
+** pointer to the FuncDef structure that defines that function, or return
+** NULL if the function does not exist.
+**
+** If the createFlag argument is true, then a new (blank) FuncDef
+** structure is created and liked into the "db" structure if a
+** no matching function previously existed.  When createFlag is true
+** and the nArg parameter is -1, then only a function that accepts
+** any number of arguments will be returned.
+**
+** If createFlag is false and nArg is -1, then the first valid
+** function found is returned.  A function is valid if either xFunc
+** or xStep is non-zero.
+**
+** If createFlag is false, then a function with the required name and
+** number of arguments may be returned even if the eTextRep flag does not
+** match that requested.
+*/
+FuncDef *sqlite3FindFunction(
+  sqlite3 *db,       /* An open database */
+  const char *zName, /* Name of the function.  Not null-terminated */
+  int nName,         /* Number of characters in the name */
+  int nArg,          /* Number of arguments.  -1 means any number */
+  u8 enc,            /* Preferred text encoding */
+  int createFlag     /* Create new entry if true and does not otherwise exist */
+){
+  FuncDef *p;         /* Iterator variable */
+  FuncDef *pFirst;    /* First function with this name */
+  FuncDef *pBest = 0; /* Best match found so far */
+  int bestmatch = 0;  
+
+
+  assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
+  if( nArg<-1 ) nArg = -1;
+
+  pFirst = (FuncDef*)sqlite3HashFind(&db->aFunc, zName, nName);
+  for(p=pFirst; p; p=p->pNext){
+    /* During the search for the best function definition, bestmatch is set
+    ** as follows to indicate the quality of the match with the definition
+    ** pointed to by pBest:
+    **
+    ** 0: pBest is NULL. No match has been found.
+    ** 1: A variable arguments function that prefers UTF-8 when a UTF-16
+    **    encoding is requested, or vice versa.
+    ** 2: A variable arguments function that uses UTF-16BE when UTF-16LE is
+    **    requested, or vice versa.
+    ** 3: A variable arguments function using the same text encoding.
+    ** 4: A function with the exact number of arguments requested that
+    **    prefers UTF-8 when a UTF-16 encoding is requested, or vice versa.
+    ** 5: A function with the exact number of arguments requested that
+    **    prefers UTF-16LE when UTF-16BE is requested, or vice versa.
+    ** 6: An exact match.
+    **
+    ** A larger value of 'matchqual' indicates a more desirable match.
+    */
+    if( p->nArg==-1 || p->nArg==nArg || nArg==-1 ){
+      int match = 1;          /* Quality of this match */
+      if( p->nArg==nArg || nArg==-1 ){
+        match = 4;
+      }
+      if( enc==p->iPrefEnc ){
+        match += 2;
+      }
+      else if( (enc==SQLITE_UTF16LE && p->iPrefEnc==SQLITE_UTF16BE) ||
+               (enc==SQLITE_UTF16BE && p->iPrefEnc==SQLITE_UTF16LE) ){
+        match += 1;
+      }
+
+      if( match>bestmatch ){
+        pBest = p;
+        bestmatch = match;
+      }
+    }
+  }
+
+  /* If the createFlag parameter is true, and the seach did not reveal an
+  ** exact match for the name, number of arguments and encoding, then add a
+  ** new entry to the hash table and return it.
+  */
+  if( createFlag && bestmatch<6 && 
+      (pBest = sqlite3DbMallocZero(db, sizeof(*pBest)+nName))!=0 ){
+    pBest->nArg = nArg;
+    pBest->pNext = pFirst;
+    pBest->iPrefEnc = enc;
+    memcpy(pBest->zName, zName, nName);
+    pBest->zName[nName] = 0;
+    if( pBest==sqlite3HashInsert(&db->aFunc,pBest->zName,nName,(void*)pBest) ){
+      db->mallocFailed = 1;
+      sqlite3DbFree(db, pBest);
+      return 0;
+    }
+  }
+
+  if( pBest && (pBest->xStep || pBest->xFunc || createFlag) ){
+    return pBest;
+  }
+  return 0;
+}
+
+/*
+** Free all resources held by the schema structure. The void* argument points
+** at a Schema struct. This function does not call sqlite3DbFree(db, ) on the 
+** pointer itself, it just cleans up subsiduary resources (i.e. the contents
+** of the schema hash tables).
+**
+** The Schema.cache_size variable is not cleared.
+*/
+void sqlite3SchemaFree(void *p){
+  Hash temp1;
+  Hash temp2;
+  HashElem *pElem;
+  Schema *pSchema = (Schema *)p;
+
+  temp1 = pSchema->tblHash;
+  temp2 = pSchema->trigHash;
+  sqlite3HashInit(&pSchema->trigHash, SQLITE_HASH_STRING, 0);
+  sqlite3HashClear(&pSchema->aFKey);
+  sqlite3HashClear(&pSchema->idxHash);
+  for(pElem=sqliteHashFirst(&temp2); pElem; pElem=sqliteHashNext(pElem)){
+    sqlite3DeleteTrigger(0, (Trigger*)sqliteHashData(pElem));
+  }
+  sqlite3HashClear(&temp2);
+  sqlite3HashInit(&pSchema->tblHash, SQLITE_HASH_STRING, 0);
+  for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){
+    Table *pTab = sqliteHashData(pElem);
+    sqlite3DeleteTable(pTab);
+  }
+  sqlite3HashClear(&temp1);
+  pSchema->pSeqTab = 0;
+  pSchema->flags &= ~DB_SchemaLoaded;
+}
+
+/*
+** Find and return the schema associated with a BTree.  Create
+** a new one if necessary.
+*/
+Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){
+  Schema * p;
+  if( pBt ){
+    p = (Schema *)sqlite3BtreeSchema(pBt, sizeof(Schema), sqlite3SchemaFree);
+  }else{
+    p = (Schema *)sqlite3MallocZero(sizeof(Schema));
+  }
+  if( !p ){
+    db->mallocFailed = 1;
+  }else if ( 0==p->file_format ){
+    sqlite3HashInit(&p->tblHash, SQLITE_HASH_STRING, 0);
+    sqlite3HashInit(&p->idxHash, SQLITE_HASH_STRING, 0);
+    sqlite3HashInit(&p->trigHash, SQLITE_HASH_STRING, 0);
+    sqlite3HashInit(&p->aFKey, SQLITE_HASH_STRING, 1);
+    p->enc = SQLITE_UTF8;
+  }
+  return p;
+}
diff --git a/third_party/sqlite/src/complete.c b/third_party/sqlite/src/complete.c
new file mode 100755
index 0000000..8e2dbc2
--- /dev/null
+++ b/third_party/sqlite/src/complete.c
@@ -0,0 +1,277 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** An tokenizer for SQL
+**
+** This file contains C code that implements the sqlite3_complete() API.
+** This code used to be part of the tokenizer.c source file.  But by
+** separating it out, the code will be automatically omitted from
+** static links that do not use it.
+**
+** $Id: complete.c,v 1.7 2008/06/13 18:24:27 drh Exp $
+*/
+#include "sqliteInt.h"
+#ifndef SQLITE_OMIT_COMPLETE
+
+/*
+** This is defined in tokenize.c.  We just have to import the definition.
+*/
+#ifndef SQLITE_AMALGAMATION
+#ifdef SQLITE_ASCII
+extern const char sqlite3IsAsciiIdChar[];
+#define IdChar(C)  (((c=C)&0x80)!=0 || (c>0x1f && sqlite3IsAsciiIdChar[c-0x20]))
+#endif
+#ifdef SQLITE_EBCDIC
+extern const char sqlite3IsEbcdicIdChar[];
+#define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
+#endif
+#endif /* SQLITE_AMALGAMATION */
+
+
+/*
+** Token types used by the sqlite3_complete() routine.  See the header
+** comments on that procedure for additional information.
+*/
+#define tkSEMI    0
+#define tkWS      1
+#define tkOTHER   2
+#define tkEXPLAIN 3
+#define tkCREATE  4
+#define tkTEMP    5
+#define tkTRIGGER 6
+#define tkEND     7
+
+/*
+** Return TRUE if the given SQL string ends in a semicolon.
+**
+** Special handling is require for CREATE TRIGGER statements.
+** Whenever the CREATE TRIGGER keywords are seen, the statement
+** must end with ";END;".
+**
+** This implementation uses a state machine with 7 states:
+**
+**   (0) START     At the beginning or end of an SQL statement.  This routine
+**                 returns 1 if it ends in the START state and 0 if it ends
+**                 in any other state.
+**
+**   (1) NORMAL    We are in the middle of statement which ends with a single
+**                 semicolon.
+**
+**   (2) EXPLAIN   The keyword EXPLAIN has been seen at the beginning of 
+**                 a statement.
+**
+**   (3) CREATE    The keyword CREATE has been seen at the beginning of a
+**                 statement, possibly preceeded by EXPLAIN and/or followed by
+**                 TEMP or TEMPORARY
+**
+**   (4) TRIGGER   We are in the middle of a trigger definition that must be
+**                 ended by a semicolon, the keyword END, and another semicolon.
+**
+**   (5) SEMI      We've seen the first semicolon in the ";END;" that occurs at
+**                 the end of a trigger definition.
+**
+**   (6) END       We've seen the ";END" of the ";END;" that occurs at the end
+**                 of a trigger difinition.
+**
+** Transitions between states above are determined by tokens extracted
+** from the input.  The following tokens are significant:
+**
+**   (0) tkSEMI      A semicolon.
+**   (1) tkWS        Whitespace
+**   (2) tkOTHER     Any other SQL token.
+**   (3) tkEXPLAIN   The "explain" keyword.
+**   (4) tkCREATE    The "create" keyword.
+**   (5) tkTEMP      The "temp" or "temporary" keyword.
+**   (6) tkTRIGGER   The "trigger" keyword.
+**   (7) tkEND       The "end" keyword.
+**
+** Whitespace never causes a state transition and is always ignored.
+**
+** If we compile with SQLITE_OMIT_TRIGGER, all of the computation needed
+** to recognize the end of a trigger can be omitted.  All we have to do
+** is look for a semicolon that is not part of an string or comment.
+*/
+int sqlite3_complete(const char *zSql){
+  u8 state = 0;   /* Current state, using numbers defined in header comment */
+  u8 token;       /* Value of the next token */
+
+#ifndef SQLITE_OMIT_TRIGGER
+  /* A complex statement machine used to detect the end of a CREATE TRIGGER
+  ** statement.  This is the normal case.
+  */
+  static const u8 trans[7][8] = {
+                     /* Token:                                                */
+     /* State:       **  SEMI  WS  OTHER EXPLAIN  CREATE  TEMP  TRIGGER  END  */
+     /* 0   START: */ {    0,  0,     1,      2,      3,    1,       1,   1,  },
+     /* 1  NORMAL: */ {    0,  1,     1,      1,      1,    1,       1,   1,  },
+     /* 2 EXPLAIN: */ {    0,  2,     1,      1,      3,    1,       1,   1,  },
+     /* 3  CREATE: */ {    0,  3,     1,      1,      1,    3,       4,   1,  },
+     /* 4 TRIGGER: */ {    5,  4,     4,      4,      4,    4,       4,   4,  },
+     /* 5    SEMI: */ {    5,  5,     4,      4,      4,    4,       4,   6,  },
+     /* 6     END: */ {    0,  6,     4,      4,      4,    4,       4,   4,  },
+  };
+#else
+  /* If triggers are not suppored by this compile then the statement machine
+  ** used to detect the end of a statement is much simplier
+  */
+  static const u8 trans[2][3] = {
+                     /* Token:           */
+     /* State:       **  SEMI  WS  OTHER */
+     /* 0   START: */ {    0,  0,     1, },
+     /* 1  NORMAL: */ {    0,  1,     1, },
+  };
+#endif /* SQLITE_OMIT_TRIGGER */
+
+  while( *zSql ){
+    switch( *zSql ){
+      case ';': {  /* A semicolon */
+        token = tkSEMI;
+        break;
+      }
+      case ' ':
+      case '\r':
+      case '\t':
+      case '\n':
+      case '\f': {  /* White space is ignored */
+        token = tkWS;
+        break;
+      }
+      case '/': {   /* C-style comments */
+        if( zSql[1]!='*' ){
+          token = tkOTHER;
+          break;
+        }
+        zSql += 2;
+        while( zSql[0] && (zSql[0]!='*' || zSql[1]!='/') ){ zSql++; }
+        if( zSql[0]==0 ) return 0;
+        zSql++;
+        token = tkWS;
+        break;
+      }
+      case '-': {   /* SQL-style comments from "--" to end of line */
+        if( zSql[1]!='-' ){
+          token = tkOTHER;
+          break;
+        }
+        while( *zSql && *zSql!='\n' ){ zSql++; }
+        if( *zSql==0 ) return state==0;
+        token = tkWS;
+        break;
+      }
+      case '[': {   /* Microsoft-style identifiers in [...] */
+        zSql++;
+        while( *zSql && *zSql!=']' ){ zSql++; }
+        if( *zSql==0 ) return 0;
+        token = tkOTHER;
+        break;
+      }
+      case '`':     /* Grave-accent quoted symbols used by MySQL */
+      case '"':     /* single- and double-quoted strings */
+      case '\'': {
+        int c = *zSql;
+        zSql++;
+        while( *zSql && *zSql!=c ){ zSql++; }
+        if( *zSql==0 ) return 0;
+        token = tkOTHER;
+        break;
+      }
+      default: {
+        int c;
+        if( IdChar((u8)*zSql) ){
+          /* Keywords and unquoted identifiers */
+          int nId;
+          for(nId=1; IdChar(zSql[nId]); nId++){}
+#ifdef SQLITE_OMIT_TRIGGER
+          token = tkOTHER;
+#else
+          switch( *zSql ){
+            case 'c': case 'C': {
+              if( nId==6 && sqlite3StrNICmp(zSql, "create", 6)==0 ){
+                token = tkCREATE;
+              }else{
+                token = tkOTHER;
+              }
+              break;
+            }
+            case 't': case 'T': {
+              if( nId==7 && sqlite3StrNICmp(zSql, "trigger", 7)==0 ){
+                token = tkTRIGGER;
+              }else if( nId==4 && sqlite3StrNICmp(zSql, "temp", 4)==0 ){
+                token = tkTEMP;
+              }else if( nId==9 && sqlite3StrNICmp(zSql, "temporary", 9)==0 ){
+                token = tkTEMP;
+              }else{
+                token = tkOTHER;
+              }
+              break;
+            }
+            case 'e':  case 'E': {
+              if( nId==3 && sqlite3StrNICmp(zSql, "end", 3)==0 ){
+                token = tkEND;
+              }else
+#ifndef SQLITE_OMIT_EXPLAIN
+              if( nId==7 && sqlite3StrNICmp(zSql, "explain", 7)==0 ){
+                token = tkEXPLAIN;
+              }else
+#endif
+              {
+                token = tkOTHER;
+              }
+              break;
+            }
+            default: {
+              token = tkOTHER;
+              break;
+            }
+          }
+#endif /* SQLITE_OMIT_TRIGGER */
+          zSql += nId-1;
+        }else{
+          /* Operators and special symbols */
+          token = tkOTHER;
+        }
+        break;
+      }
+    }
+    state = trans[state][token];
+    zSql++;
+  }
+  return state==0;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** This routine is the same as the sqlite3_complete() routine described
+** above, except that the parameter is required to be UTF-16 encoded, not
+** UTF-8.
+*/
+int sqlite3_complete16(const void *zSql){
+  sqlite3_value *pVal;
+  char const *zSql8;
+  int rc = SQLITE_NOMEM;
+
+#ifndef SQLITE_OMIT_AUTOINIT
+  rc = sqlite3_initialize();
+  if( rc ) return rc;
+#endif
+  pVal = sqlite3ValueNew(0);
+  sqlite3ValueSetStr(pVal, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC);
+  zSql8 = sqlite3ValueText(pVal, SQLITE_UTF8);
+  if( zSql8 ){
+    rc = sqlite3_complete(zSql8);
+  }else{
+    rc = SQLITE_NOMEM;
+  }
+  sqlite3ValueFree(pVal);
+  return sqlite3ApiExit(0, rc);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+#endif /* SQLITE_OMIT_COMPLETE */
diff --git a/third_party/sqlite/src/date.c b/third_party/sqlite/src/date.c
new file mode 100755
index 0000000..08ee30c
--- /dev/null
+++ b/third_party/sqlite/src/date.c
@@ -0,0 +1,1093 @@
+/*
+** 2003 October 31
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the C functions that implement date and time
+** functions for SQLite.  
+**
+** There is only one exported symbol in this file - the function
+** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
+** All other code has file scope.
+**
+** $Id: date.c,v 1.87 2008/07/28 19:34:53 drh Exp $
+**
+** SQLite processes all times and dates as Julian Day numbers.  The
+** dates and times are stored as the number of days since noon
+** in Greenwich on November 24, 4714 B.C. according to the Gregorian
+** calendar system. 
+**
+** 1970-01-01 00:00:00 is JD 2440587.5
+** 2000-01-01 00:00:00 is JD 2451544.5
+**
+** This implemention requires years to be expressed as a 4-digit number
+** which means that only dates between 0000-01-01 and 9999-12-31 can
+** be represented, even though julian day numbers allow a much wider
+** range of dates.
+**
+** The Gregorian calendar system is used for all dates and times,
+** even those that predate the Gregorian calendar.  Historians usually
+** use the Julian calendar for dates prior to 1582-10-15 and for some
+** dates afterwards, depending on locale.  Beware of this difference.
+**
+** The conversion algorithms are implemented based on descriptions
+** in the following text:
+**
+**      Jean Meeus
+**      Astronomical Algorithms, 2nd Edition, 1998
+**      ISBM 0-943396-61-1
+**      Willmann-Bell, Inc
+**      Richmond, Virginia (USA)
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <time.h>
+
+#ifndef SQLITE_OMIT_DATETIME_FUNCS
+
+/*
+** On recent Windows platforms, the localtime_s() function is available
+** as part of the "Secure CRT". It is essentially equivalent to 
+** localtime_r() available under most POSIX platforms, except that the 
+** order of the parameters is reversed.
+**
+** See http://msdn.microsoft.com/en-us/library/a442x3ye(VS.80).aspx.
+**
+** If the user has not indicated to use localtime_r() or localtime_s()
+** already, check for an MSVC build environment that provides 
+** localtime_s().
+*/
+#if !defined(HAVE_LOCALTIME_R) && !defined(HAVE_LOCALTIME_S) && \
+     defined(_MSC_VER) && defined(_CRT_INSECURE_DEPRECATE)
+#define HAVE_LOCALTIME_S 1
+#endif
+
+/*
+** A structure for holding a single date and time.
+*/
+typedef struct DateTime DateTime;
+struct DateTime {
+  sqlite3_int64 iJD; /* The julian day number times 86400000 */
+  int Y, M, D;       /* Year, month, and day */
+  int h, m;          /* Hour and minutes */
+  int tz;            /* Timezone offset in minutes */
+  double s;          /* Seconds */
+  char validYMD;     /* True if Y,M,D are valid */
+  char validHMS;     /* True if h,m,s are valid */
+  char validJD;      /* True if iJD is valid */
+  char validTZ;      /* True if tz is valid */
+};
+
+
+/*
+** Convert zDate into one or more integers.  Additional arguments
+** come in groups of 5 as follows:
+**
+**       N       number of digits in the integer
+**       min     minimum allowed value of the integer
+**       max     maximum allowed value of the integer
+**       nextC   first character after the integer
+**       pVal    where to write the integers value.
+**
+** Conversions continue until one with nextC==0 is encountered.
+** The function returns the number of successful conversions.
+*/
+static int getDigits(const char *zDate, ...){
+  va_list ap;
+  int val;
+  int N;
+  int min;
+  int max;
+  int nextC;
+  int *pVal;
+  int cnt = 0;
+  va_start(ap, zDate);
+  do{
+    N = va_arg(ap, int);
+    min = va_arg(ap, int);
+    max = va_arg(ap, int);
+    nextC = va_arg(ap, int);
+    pVal = va_arg(ap, int*);
+    val = 0;
+    while( N-- ){
+      if( !isdigit(*(u8*)zDate) ){
+        goto end_getDigits;
+      }
+      val = val*10 + *zDate - '0';
+      zDate++;
+    }
+    if( val<min || val>max || (nextC!=0 && nextC!=*zDate) ){
+      goto end_getDigits;
+    }
+    *pVal = val;
+    zDate++;
+    cnt++;
+  }while( nextC );
+end_getDigits:
+  va_end(ap);
+  return cnt;
+}
+
+/*
+** Read text from z[] and convert into a floating point number.  Return
+** the number of digits converted.
+*/
+#define getValue sqlite3AtoF
+
+/*
+** Parse a timezone extension on the end of a date-time.
+** The extension is of the form:
+**
+**        (+/-)HH:MM
+**
+** Or the "zulu" notation:
+**
+**        Z
+**
+** If the parse is successful, write the number of minutes
+** of change in p->tz and return 0.  If a parser error occurs,
+** return non-zero.
+**
+** A missing specifier is not considered an error.
+*/
+static int parseTimezone(const char *zDate, DateTime *p){
+  int sgn = 0;
+  int nHr, nMn;
+  int c;
+  while( isspace(*(u8*)zDate) ){ zDate++; }
+  p->tz = 0;
+  c = *zDate;
+  if( c=='-' ){
+    sgn = -1;
+  }else if( c=='+' ){
+    sgn = +1;
+  }else if( c=='Z' || c=='z' ){
+    zDate++;
+    goto zulu_time;
+  }else{
+    return c!=0;
+  }
+  zDate++;
+  if( getDigits(zDate, 2, 0, 14, ':', &nHr, 2, 0, 59, 0, &nMn)!=2 ){
+    return 1;
+  }
+  zDate += 5;
+  p->tz = sgn*(nMn + nHr*60);
+zulu_time:
+  while( isspace(*(u8*)zDate) ){ zDate++; }
+  return *zDate!=0;
+}
+
+/*
+** Parse times of the form HH:MM or HH:MM:SS or HH:MM:SS.FFFF.
+** The HH, MM, and SS must each be exactly 2 digits.  The
+** fractional seconds FFFF can be one or more digits.
+**
+** Return 1 if there is a parsing error and 0 on success.
+*/
+static int parseHhMmSs(const char *zDate, DateTime *p){
+  int h, m, s;
+  double ms = 0.0;
+  if( getDigits(zDate, 2, 0, 24, ':', &h, 2, 0, 59, 0, &m)!=2 ){
+    return 1;
+  }
+  zDate += 5;
+  if( *zDate==':' ){
+    zDate++;
+    if( getDigits(zDate, 2, 0, 59, 0, &s)!=1 ){
+      return 1;
+    }
+    zDate += 2;
+    if( *zDate=='.' && isdigit((u8)zDate[1]) ){
+      double rScale = 1.0;
+      zDate++;
+      while( isdigit(*(u8*)zDate) ){
+        ms = ms*10.0 + *zDate - '0';
+        rScale *= 10.0;
+        zDate++;
+      }
+      ms /= rScale;
+    }
+  }else{
+    s = 0;
+  }
+  p->validJD = 0;
+  p->validHMS = 1;
+  p->h = h;
+  p->m = m;
+  p->s = s + ms;
+  if( parseTimezone(zDate, p) ) return 1;
+  p->validTZ = p->tz!=0;
+  return 0;
+}
+
+/*
+** Convert from YYYY-MM-DD HH:MM:SS to julian day.  We always assume
+** that the YYYY-MM-DD is according to the Gregorian calendar.
+**
+** Reference:  Meeus page 61
+*/
+static void computeJD(DateTime *p){
+  int Y, M, D, A, B, X1, X2;
+
+  if( p->validJD ) return;
+  if( p->validYMD ){
+    Y = p->Y;
+    M = p->M;
+    D = p->D;
+  }else{
+    Y = 2000;  /* If no YMD specified, assume 2000-Jan-01 */
+    M = 1;
+    D = 1;
+  }
+  if( M<=2 ){
+    Y--;
+    M += 12;
+  }
+  A = Y/100;
+  B = 2 - A + (A/4);
+  X1 = 365.25*(Y+4716);
+  X2 = 30.6001*(M+1);
+  p->iJD = (X1 + X2 + D + B - 1524.5)*86400000;
+  p->validJD = 1;
+  if( p->validHMS ){
+    p->iJD += p->h*3600000 + p->m*60000 + p->s*1000;
+    if( p->validTZ ){
+      p->iJD -= p->tz*60000;
+      p->validYMD = 0;
+      p->validHMS = 0;
+      p->validTZ = 0;
+    }
+  }
+}
+
+/*
+** Parse dates of the form
+**
+**     YYYY-MM-DD HH:MM:SS.FFF
+**     YYYY-MM-DD HH:MM:SS
+**     YYYY-MM-DD HH:MM
+**     YYYY-MM-DD
+**
+** Write the result into the DateTime structure and return 0
+** on success and 1 if the input string is not a well-formed
+** date.
+*/
+static int parseYyyyMmDd(const char *zDate, DateTime *p){
+  int Y, M, D, neg;
+
+  if( zDate[0]=='-' ){
+    zDate++;
+    neg = 1;
+  }else{
+    neg = 0;
+  }
+  if( getDigits(zDate,4,0,9999,'-',&Y,2,1,12,'-',&M,2,1,31,0,&D)!=3 ){
+    return 1;
+  }
+  zDate += 10;
+  while( isspace(*(u8*)zDate) || 'T'==*(u8*)zDate ){ zDate++; }
+  if( parseHhMmSs(zDate, p)==0 ){
+    /* We got the time */
+  }else if( *zDate==0 ){
+    p->validHMS = 0;
+  }else{
+    return 1;
+  }
+  p->validJD = 0;
+  p->validYMD = 1;
+  p->Y = neg ? -Y : Y;
+  p->M = M;
+  p->D = D;
+  if( p->validTZ ){
+    computeJD(p);
+  }
+  return 0;
+}
+
+/*
+** Set the time to the current time reported by the VFS
+*/
+static void setDateTimeToCurrent(sqlite3_context *context, DateTime *p){
+  double r;
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  sqlite3OsCurrentTime(db->pVfs, &r);
+  p->iJD = (sqlite3_int64)(r*86400000.0 + 0.5);
+  p->validJD = 1;
+}
+
+/*
+** Attempt to parse the given string into a Julian Day Number.  Return
+** the number of errors.
+**
+** The following are acceptable forms for the input string:
+**
+**      YYYY-MM-DD HH:MM:SS.FFF  +/-HH:MM
+**      DDDD.DD 
+**      now
+**
+** In the first form, the +/-HH:MM is always optional.  The fractional
+** seconds extension (the ".FFF") is optional.  The seconds portion
+** (":SS.FFF") is option.  The year and date can be omitted as long
+** as there is a time string.  The time string can be omitted as long
+** as there is a year and date.
+*/
+static int parseDateOrTime(
+  sqlite3_context *context, 
+  const char *zDate, 
+  DateTime *p
+){
+  if( parseYyyyMmDd(zDate,p)==0 ){
+    return 0;
+  }else if( parseHhMmSs(zDate, p)==0 ){
+    return 0;
+  }else if( sqlite3StrICmp(zDate,"now")==0){
+    setDateTimeToCurrent(context, p);
+    return 0;
+  }else if( sqlite3IsNumber(zDate, 0, SQLITE_UTF8) ){
+    double r;
+    getValue(zDate, &r);
+    p->iJD = (sqlite3_int64)(r*86400000.0 + 0.5);
+    p->validJD = 1;
+    return 0;
+  }
+  return 1;
+}
+
+/*
+** Compute the Year, Month, and Day from the julian day number.
+*/
+static void computeYMD(DateTime *p){
+  int Z, A, B, C, D, E, X1;
+  if( p->validYMD ) return;
+  if( !p->validJD ){
+    p->Y = 2000;
+    p->M = 1;
+    p->D = 1;
+  }else{
+    Z = (p->iJD + 43200000)/86400000;
+    A = (Z - 1867216.25)/36524.25;
+    A = Z + 1 + A - (A/4);
+    B = A + 1524;
+    C = (B - 122.1)/365.25;
+    D = 365.25*C;
+    E = (B-D)/30.6001;
+    X1 = 30.6001*E;
+    p->D = B - D - X1;
+    p->M = E<14 ? E-1 : E-13;
+    p->Y = p->M>2 ? C - 4716 : C - 4715;
+  }
+  p->validYMD = 1;
+}
+
+/*
+** Compute the Hour, Minute, and Seconds from the julian day number.
+*/
+static void computeHMS(DateTime *p){
+  int s;
+  if( p->validHMS ) return;
+  computeJD(p);
+  s = (p->iJD + 43200000) % 86400000;
+  p->s = s/1000.0;
+  s = p->s;
+  p->s -= s;
+  p->h = s/3600;
+  s -= p->h*3600;
+  p->m = s/60;
+  p->s += s - p->m*60;
+  p->validHMS = 1;
+}
+
+/*
+** Compute both YMD and HMS
+*/
+static void computeYMD_HMS(DateTime *p){
+  computeYMD(p);
+  computeHMS(p);
+}
+
+/*
+** Clear the YMD and HMS and the TZ
+*/
+static void clearYMD_HMS_TZ(DateTime *p){
+  p->validYMD = 0;
+  p->validHMS = 0;
+  p->validTZ = 0;
+}
+
+#ifndef SQLITE_OMIT_LOCALTIME
+/*
+** Compute the difference (in milliseconds)
+** between localtime and UTC (a.k.a. GMT)
+** for the time value p where p is in UTC.
+*/
+static int localtimeOffset(DateTime *p){
+  DateTime x, y;
+  time_t t;
+  x = *p;
+  computeYMD_HMS(&x);
+  if( x.Y<1971 || x.Y>=2038 ){
+    x.Y = 2000;
+    x.M = 1;
+    x.D = 1;
+    x.h = 0;
+    x.m = 0;
+    x.s = 0.0;
+  } else {
+    int s = x.s + 0.5;
+    x.s = s;
+  }
+  x.tz = 0;
+  x.validJD = 0;
+  computeJD(&x);
+  t = x.iJD/1000 - 2440587.5*86400.0;
+#ifdef HAVE_LOCALTIME_R
+  {
+    struct tm sLocal;
+    localtime_r(&t, &sLocal);
+    y.Y = sLocal.tm_year + 1900;
+    y.M = sLocal.tm_mon + 1;
+    y.D = sLocal.tm_mday;
+    y.h = sLocal.tm_hour;
+    y.m = sLocal.tm_min;
+    y.s = sLocal.tm_sec;
+  }
+#elif defined(HAVE_LOCALTIME_S)
+  {
+    struct tm sLocal;
+    localtime_s(&sLocal, &t);
+    y.Y = sLocal.tm_year + 1900;
+    y.M = sLocal.tm_mon + 1;
+    y.D = sLocal.tm_mday;
+    y.h = sLocal.tm_hour;
+    y.m = sLocal.tm_min;
+    y.s = sLocal.tm_sec;
+  }
+#else
+  {
+    struct tm *pTm;
+    sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+    pTm = localtime(&t);
+    y.Y = pTm->tm_year + 1900;
+    y.M = pTm->tm_mon + 1;
+    y.D = pTm->tm_mday;
+    y.h = pTm->tm_hour;
+    y.m = pTm->tm_min;
+    y.s = pTm->tm_sec;
+    sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  }
+#endif
+  y.validYMD = 1;
+  y.validHMS = 1;
+  y.validJD = 0;
+  y.validTZ = 0;
+  computeJD(&y);
+  return y.iJD - x.iJD;
+}
+#endif /* SQLITE_OMIT_LOCALTIME */
+
+/*
+** Process a modifier to a date-time stamp.  The modifiers are
+** as follows:
+**
+**     NNN days
+**     NNN hours
+**     NNN minutes
+**     NNN.NNNN seconds
+**     NNN months
+**     NNN years
+**     start of month
+**     start of year
+**     start of week
+**     start of day
+**     weekday N
+**     unixepoch
+**     localtime
+**     utc
+**
+** Return 0 on success and 1 if there is any kind of error.
+*/
+static int parseModifier(const char *zMod, DateTime *p){
+  int rc = 1;
+  int n;
+  double r;
+  char *z, zBuf[30];
+  z = zBuf;
+  for(n=0; n<sizeof(zBuf)-1 && zMod[n]; n++){
+    z[n] = tolower(zMod[n]);
+  }
+  z[n] = 0;
+  switch( z[0] ){
+#ifndef SQLITE_OMIT_LOCALTIME
+    case 'l': {
+      /*    localtime
+      **
+      ** Assuming the current time value is UTC (a.k.a. GMT), shift it to
+      ** show local time.
+      */
+      if( strcmp(z, "localtime")==0 ){
+        computeJD(p);
+        p->iJD += localtimeOffset(p);
+        clearYMD_HMS_TZ(p);
+        rc = 0;
+      }
+      break;
+    }
+#endif
+    case 'u': {
+      /*
+      **    unixepoch
+      **
+      ** Treat the current value of p->iJD as the number of
+      ** seconds since 1970.  Convert to a real julian day number.
+      */
+      if( strcmp(z, "unixepoch")==0 && p->validJD ){
+        p->iJD = p->iJD/86400.0 + 2440587.5*86400000.0;
+        clearYMD_HMS_TZ(p);
+        rc = 0;
+      }
+#ifndef SQLITE_OMIT_LOCALTIME
+      else if( strcmp(z, "utc")==0 ){
+        double c1;
+        computeJD(p);
+        c1 = localtimeOffset(p);
+        p->iJD -= c1;
+        clearYMD_HMS_TZ(p);
+        p->iJD += c1 - localtimeOffset(p);
+        rc = 0;
+      }
+#endif
+      break;
+    }
+    case 'w': {
+      /*
+      **    weekday N
+      **
+      ** Move the date to the same time on the next occurrence of
+      ** weekday N where 0==Sunday, 1==Monday, and so forth.  If the
+      ** date is already on the appropriate weekday, this is a no-op.
+      */
+      if( strncmp(z, "weekday ", 8)==0 && getValue(&z[8],&r)>0
+                 && (n=r)==r && n>=0 && r<7 ){
+        sqlite3_int64 Z;
+        computeYMD_HMS(p);
+        p->validTZ = 0;
+        p->validJD = 0;
+        computeJD(p);
+        Z = ((p->iJD + 129600000)/86400000) % 7;
+        if( Z>n ) Z -= 7;
+        p->iJD += (n - Z)*86400000;
+        clearYMD_HMS_TZ(p);
+        rc = 0;
+      }
+      break;
+    }
+    case 's': {
+      /*
+      **    start of TTTTT
+      **
+      ** Move the date backwards to the beginning of the current day,
+      ** or month or year.
+      */
+      if( strncmp(z, "start of ", 9)!=0 ) break;
+      z += 9;
+      computeYMD(p);
+      p->validHMS = 1;
+      p->h = p->m = 0;
+      p->s = 0.0;
+      p->validTZ = 0;
+      p->validJD = 0;
+      if( strcmp(z,"month")==0 ){
+        p->D = 1;
+        rc = 0;
+      }else if( strcmp(z,"year")==0 ){
+        computeYMD(p);
+        p->M = 1;
+        p->D = 1;
+        rc = 0;
+      }else if( strcmp(z,"day")==0 ){
+        rc = 0;
+      }
+      break;
+    }
+    case '+':
+    case '-':
+    case '0':
+    case '1':
+    case '2':
+    case '3':
+    case '4':
+    case '5':
+    case '6':
+    case '7':
+    case '8':
+    case '9': {
+      n = getValue(z, &r);
+      assert( n>=1 );
+      if( z[n]==':' ){
+        /* A modifier of the form (+|-)HH:MM:SS.FFF adds (or subtracts) the
+        ** specified number of hours, minutes, seconds, and fractional seconds
+        ** to the time.  The ".FFF" may be omitted.  The ":SS.FFF" may be
+        ** omitted.
+        */
+        const char *z2 = z;
+        DateTime tx;
+        sqlite3_int64 day;
+        if( !isdigit(*(u8*)z2) ) z2++;
+        memset(&tx, 0, sizeof(tx));
+        if( parseHhMmSs(z2, &tx) ) break;
+        computeJD(&tx);
+        tx.iJD -= 43200000;
+        day = tx.iJD/86400000;
+        tx.iJD -= day*86400000;
+        if( z[0]=='-' ) tx.iJD = -tx.iJD;
+        computeJD(p);
+        clearYMD_HMS_TZ(p);
+        p->iJD += tx.iJD;
+        rc = 0;
+        break;
+      }
+      z += n;
+      while( isspace(*(u8*)z) ) z++;
+      n = strlen(z);
+      if( n>10 || n<3 ) break;
+      if( z[n-1]=='s' ){ z[n-1] = 0; n--; }
+      computeJD(p);
+      rc = 0;
+      if( n==3 && strcmp(z,"day")==0 ){
+        p->iJD += r*86400000.0 + 0.5;
+      }else if( n==4 && strcmp(z,"hour")==0 ){
+        p->iJD += r*(86400000.0/24.0) + 0.5;
+      }else if( n==6 && strcmp(z,"minute")==0 ){
+        p->iJD += r*(86400000.0/(24.0*60.0)) + 0.5;
+      }else if( n==6 && strcmp(z,"second")==0 ){
+        p->iJD += r*(86400000.0/(24.0*60.0*60.0)) + 0.5;
+      }else if( n==5 && strcmp(z,"month")==0 ){
+        int x, y;
+        computeYMD_HMS(p);
+        p->M += r;
+        x = p->M>0 ? (p->M-1)/12 : (p->M-12)/12;
+        p->Y += x;
+        p->M -= x*12;
+        p->validJD = 0;
+        computeJD(p);
+        y = r;
+        if( y!=r ){
+          p->iJD += (r - y)*30.0*86400000.0 + 0.5;
+        }
+      }else if( n==4 && strcmp(z,"year")==0 ){
+        computeYMD_HMS(p);
+        p->Y += r;
+        p->validJD = 0;
+        computeJD(p);
+      }else{
+        rc = 1;
+      }
+      clearYMD_HMS_TZ(p);
+      break;
+    }
+    default: {
+      break;
+    }
+  }
+  return rc;
+}
+
+/*
+** Process time function arguments.  argv[0] is a date-time stamp.
+** argv[1] and following are modifiers.  Parse them all and write
+** the resulting time into the DateTime structure p.  Return 0
+** on success and 1 if there are any errors.
+**
+** If there are zero parameters (if even argv[0] is undefined)
+** then assume a default value of "now" for argv[0].
+*/
+static int isDate(
+  sqlite3_context *context, 
+  int argc, 
+  sqlite3_value **argv, 
+  DateTime *p
+){
+  int i;
+  const unsigned char *z;
+  int eType;
+  memset(p, 0, sizeof(*p));
+  if( argc==0 ){
+    setDateTimeToCurrent(context, p);
+  }else if( (eType = sqlite3_value_type(argv[0]))==SQLITE_FLOAT
+                   || eType==SQLITE_INTEGER ){
+    p->iJD = sqlite3_value_double(argv[0])*86400000.0 + 0.5;
+    p->validJD = 1;
+  }else{
+    z = sqlite3_value_text(argv[0]);
+    if( !z || parseDateOrTime(context, (char*)z, p) ){
+      return 1;
+    }
+  }
+  for(i=1; i<argc; i++){
+    if( (z = sqlite3_value_text(argv[i]))==0 || parseModifier((char*)z, p) ){
+      return 1;
+    }
+  }
+  return 0;
+}
+
+
+/*
+** The following routines implement the various date and time functions
+** of SQLite.
+*/
+
+/*
+**    julianday( TIMESTRING, MOD, MOD, ...)
+**
+** Return the julian day number of the date specified in the arguments
+*/
+static void juliandayFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  DateTime x;
+  if( isDate(context, argc, argv, &x)==0 ){
+    computeJD(&x);
+    sqlite3_result_double(context, x.iJD/86400000.0);
+  }
+}
+
+/*
+**    datetime( TIMESTRING, MOD, MOD, ...)
+**
+** Return YYYY-MM-DD HH:MM:SS
+*/
+static void datetimeFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  DateTime x;
+  if( isDate(context, argc, argv, &x)==0 ){
+    char zBuf[100];
+    computeYMD_HMS(&x);
+    sqlite3_snprintf(sizeof(zBuf), zBuf, "%04d-%02d-%02d %02d:%02d:%02d",
+                     x.Y, x.M, x.D, x.h, x.m, (int)(x.s));
+    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
+  }
+}
+
+/*
+**    time( TIMESTRING, MOD, MOD, ...)
+**
+** Return HH:MM:SS
+*/
+static void timeFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  DateTime x;
+  if( isDate(context, argc, argv, &x)==0 ){
+    char zBuf[100];
+    computeHMS(&x);
+    sqlite3_snprintf(sizeof(zBuf), zBuf, "%02d:%02d:%02d", x.h, x.m, (int)x.s);
+    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
+  }
+}
+
+/*
+**    date( TIMESTRING, MOD, MOD, ...)
+**
+** Return YYYY-MM-DD
+*/
+static void dateFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  DateTime x;
+  if( isDate(context, argc, argv, &x)==0 ){
+    char zBuf[100];
+    computeYMD(&x);
+    sqlite3_snprintf(sizeof(zBuf), zBuf, "%04d-%02d-%02d", x.Y, x.M, x.D);
+    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
+  }
+}
+
+/*
+**    strftime( FORMAT, TIMESTRING, MOD, MOD, ...)
+**
+** Return a string described by FORMAT.  Conversions as follows:
+**
+**   %d  day of month
+**   %f  ** fractional seconds  SS.SSS
+**   %H  hour 00-24
+**   %j  day of year 000-366
+**   %J  ** Julian day number
+**   %m  month 01-12
+**   %M  minute 00-59
+**   %s  seconds since 1970-01-01
+**   %S  seconds 00-59
+**   %w  day of week 0-6  sunday==0
+**   %W  week of year 00-53
+**   %Y  year 0000-9999
+**   %%  %
+*/
+static void strftimeFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  DateTime x;
+  u64 n;
+  int i, j;
+  char *z;
+  sqlite3 *db;
+  const char *zFmt = (const char*)sqlite3_value_text(argv[0]);
+  char zBuf[100];
+  if( zFmt==0 || isDate(context, argc-1, argv+1, &x) ) return;
+  db = sqlite3_context_db_handle(context);
+  for(i=0, n=1; zFmt[i]; i++, n++){
+    if( zFmt[i]=='%' ){
+      switch( zFmt[i+1] ){
+        case 'd':
+        case 'H':
+        case 'm':
+        case 'M':
+        case 'S':
+        case 'W':
+          n++;
+          /* fall thru */
+        case 'w':
+        case '%':
+          break;
+        case 'f':
+          n += 8;
+          break;
+        case 'j':
+          n += 3;
+          break;
+        case 'Y':
+          n += 8;
+          break;
+        case 's':
+        case 'J':
+          n += 50;
+          break;
+        default:
+          return;  /* ERROR.  return a NULL */
+      }
+      i++;
+    }
+  }
+  if( n<sizeof(zBuf) ){
+    z = zBuf;
+  }else if( n>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    sqlite3_result_error_toobig(context);
+    return;
+  }else{
+    z = sqlite3DbMallocRaw(db, n);
+    if( z==0 ){
+      sqlite3_result_error_nomem(context);
+      return;
+    }
+  }
+  computeJD(&x);
+  computeYMD_HMS(&x);
+  for(i=j=0; zFmt[i]; i++){
+    if( zFmt[i]!='%' ){
+      z[j++] = zFmt[i];
+    }else{
+      i++;
+      switch( zFmt[i] ){
+        case 'd':  sqlite3_snprintf(3, &z[j],"%02d",x.D); j+=2; break;
+        case 'f': {
+          double s = x.s;
+          if( s>59.999 ) s = 59.999;
+          sqlite3_snprintf(7, &z[j],"%06.3f", s);
+          j += strlen(&z[j]);
+          break;
+        }
+        case 'H':  sqlite3_snprintf(3, &z[j],"%02d",x.h); j+=2; break;
+        case 'W': /* Fall thru */
+        case 'j': {
+          int nDay;             /* Number of days since 1st day of year */
+          DateTime y = x;
+          y.validJD = 0;
+          y.M = 1;
+          y.D = 1;
+          computeJD(&y);
+          nDay = (x.iJD - y.iJD)/86400000.0 + 0.5;
+          if( zFmt[i]=='W' ){
+            int wd;   /* 0=Monday, 1=Tuesday, ... 6=Sunday */
+            wd = ((x.iJD+43200000)/86400000) % 7;
+            sqlite3_snprintf(3, &z[j],"%02d",(nDay+7-wd)/7);
+            j += 2;
+          }else{
+            sqlite3_snprintf(4, &z[j],"%03d",nDay+1);
+            j += 3;
+          }
+          break;
+        }
+        case 'J': {
+          sqlite3_snprintf(20, &z[j],"%.16g",x.iJD/86400000.0);
+          j+=strlen(&z[j]);
+          break;
+        }
+        case 'm':  sqlite3_snprintf(3, &z[j],"%02d",x.M); j+=2; break;
+        case 'M':  sqlite3_snprintf(3, &z[j],"%02d",x.m); j+=2; break;
+        case 's': {
+          sqlite3_snprintf(30,&z[j],"%d",
+                           (int)(x.iJD/1000.0 - 210866760000.0));
+          j += strlen(&z[j]);
+          break;
+        }
+        case 'S':  sqlite3_snprintf(3,&z[j],"%02d",(int)x.s); j+=2; break;
+        case 'w':  z[j++] = (((x.iJD+129600000)/86400000) % 7) + '0'; break;
+        case 'Y':  sqlite3_snprintf(5,&z[j],"%04d",x.Y); j+=strlen(&z[j]);break;
+        default:   z[j++] = '%'; break;
+      }
+    }
+  }
+  z[j] = 0;
+  sqlite3_result_text(context, z, -1,
+                      z==zBuf ? SQLITE_TRANSIENT : SQLITE_DYNAMIC);
+}
+
+/*
+** current_time()
+**
+** This function returns the same value as time('now').
+*/
+static void ctimeFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  timeFunc(context, 0, 0);
+}
+
+/*
+** current_date()
+**
+** This function returns the same value as date('now').
+*/
+static void cdateFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  dateFunc(context, 0, 0);
+}
+
+/*
+** current_timestamp()
+**
+** This function returns the same value as datetime('now').
+*/
+static void ctimestampFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  datetimeFunc(context, 0, 0);
+}
+#endif /* !defined(SQLITE_OMIT_DATETIME_FUNCS) */
+
+#ifdef SQLITE_OMIT_DATETIME_FUNCS
+/*
+** If the library is compiled to omit the full-scale date and time
+** handling (to get a smaller binary), the following minimal version
+** of the functions current_time(), current_date() and current_timestamp()
+** are included instead. This is to support column declarations that
+** include "DEFAULT CURRENT_TIME" etc.
+**
+** This function uses the C-library functions time(), gmtime()
+** and strftime(). The format string to pass to strftime() is supplied
+** as the user-data for the function.
+*/
+static void currentTimeFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  time_t t;
+  char *zFormat = (char *)sqlite3_user_data(context);
+  sqlite3 *db;
+  double rT;
+  char zBuf[20];
+
+  db = sqlite3_context_db_handle(context);
+  sqlite3OsCurrentTime(db->pVfs, &rT);
+  t = 86400.0*(rT - 2440587.5) + 0.5;
+#ifdef HAVE_GMTIME_R
+  {
+    struct tm sNow;
+    gmtime_r(&t, &sNow);
+    strftime(zBuf, 20, zFormat, &sNow);
+  }
+#else
+  {
+    struct tm *pTm;
+    sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+    pTm = gmtime(&t);
+    strftime(zBuf, 20, zFormat, pTm);
+    sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  }
+#endif
+
+  sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
+}
+#endif
+
+/*
+** This function registered all of the above C functions as SQL
+** functions.  This should be the only routine in this file with
+** external linkage.
+*/
+void sqlite3RegisterDateTimeFunctions(sqlite3 *db){
+#ifndef SQLITE_OMIT_DATETIME_FUNCS
+  static const struct {
+     char *zName;
+     int nArg;
+     void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
+  } aFuncs[] = {
+    { "julianday", -1, juliandayFunc   },
+    { "date",      -1, dateFunc        },
+    { "time",      -1, timeFunc        },
+    { "datetime",  -1, datetimeFunc    },
+    { "strftime",  -1, strftimeFunc    },
+    { "current_time",       0, ctimeFunc      },
+    { "current_timestamp",  0, ctimestampFunc },
+    { "current_date",       0, cdateFunc      },
+  };
+  int i;
+
+  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
+    sqlite3CreateFunc(db, aFuncs[i].zName, aFuncs[i].nArg,
+        SQLITE_UTF8, 0, aFuncs[i].xFunc, 0, 0);
+  }
+#else
+  static const struct {
+     char *zName;
+     char *zFormat;
+  } aFuncs[] = {
+    { "current_time", "%H:%M:%S" },
+    { "current_date", "%Y-%m-%d" },
+    { "current_timestamp", "%Y-%m-%d %H:%M:%S" }
+  };
+  int i;
+
+  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
+    sqlite3CreateFunc(db, aFuncs[i].zName, 0, SQLITE_UTF8, 
+        aFuncs[i].zFormat, currentTimeFunc, 0, 0);
+  }
+#endif
+}
diff --git a/third_party/sqlite/src/delete.c b/third_party/sqlite/src/delete.c
new file mode 100755
index 0000000..2682424
--- /dev/null
+++ b/third_party/sqlite/src/delete.c
@@ -0,0 +1,544 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains C code routines that are called by the parser
+** in order to generate code for DELETE FROM statements.
+**
+** $Id: delete.c,v 1.171 2008/07/28 19:34:53 drh Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** Look up every table that is named in pSrc.  If any table is not found,
+** add an error message to pParse->zErrMsg and return NULL.  If all tables
+** are found, return a pointer to the last table.
+*/
+Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
+  Table *pTab = 0;
+  int i;
+  struct SrcList_item *pItem;
+  for(i=0, pItem=pSrc->a; i<pSrc->nSrc; i++, pItem++){
+    pTab = sqlite3LocateTable(pParse, 0, pItem->zName, pItem->zDatabase);
+    sqlite3DeleteTable(pItem->pTab);
+    pItem->pTab = pTab;
+    if( pTab ){
+      pTab->nRef++;
+    }
+  }
+  return pTab;
+}
+
+/*
+** Check to make sure the given table is writable.  If it is not
+** writable, generate an error message and return 1.  If it is
+** writable return 0;
+*/
+int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){
+  if( (pTab->readOnly && (pParse->db->flags & SQLITE_WriteSchema)==0
+        && pParse->nested==0) 
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+      || (pTab->pMod && pTab->pMod->pModule->xUpdate==0)
+#endif
+  ){
+    sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);
+    return 1;
+  }
+#ifndef SQLITE_OMIT_VIEW
+  if( !viewOk && pTab->pSelect ){
+    sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
+    return 1;
+  }
+#endif
+  return 0;
+}
+
+/*
+** Generate code that will open a table for reading.
+*/
+void sqlite3OpenTable(
+  Parse *p,       /* Generate code into this VDBE */
+  int iCur,       /* The cursor number of the table */
+  int iDb,        /* The database index in sqlite3.aDb[] */
+  Table *pTab,    /* The table to be opened */
+  int opcode      /* OP_OpenRead or OP_OpenWrite */
+){
+  Vdbe *v;
+  if( IsVirtual(pTab) ) return;
+  v = sqlite3GetVdbe(p);
+  assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
+  sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite), pTab->zName);
+  sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
+  sqlite3VdbeAddOp3(v, opcode, iCur, pTab->tnum, iDb);
+  VdbeComment((v, "%s", pTab->zName));
+}
+
+
+#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
+/*
+** Evaluate a view and store its result in an ephemeral table.  The
+** pWhere argument is an optional WHERE clause that restricts the
+** set of rows in the view that are to be added to the ephemeral table.
+*/
+void sqlite3MaterializeView(
+  Parse *pParse,       /* Parsing context */
+  Select *pView,       /* View definition */
+  Expr *pWhere,        /* Optional WHERE clause to be added */
+  int iCur             /* Cursor number for ephemerial table */
+){
+  SelectDest dest;
+  Select *pDup;
+  sqlite3 *db = pParse->db;
+
+  pDup = sqlite3SelectDup(db, pView);
+  if( pWhere ){
+    SrcList *pFrom;
+    
+    pWhere = sqlite3ExprDup(db, pWhere);
+    pFrom = sqlite3SrcListAppendFromTerm(pParse, 0, 0, 0, 0, pDup, 0, 0);
+    pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
+  }
+  sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
+  sqlite3Select(pParse, pDup, &dest, 0, 0, 0);
+  sqlite3SelectDelete(db, pDup);
+}
+#endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */
+
+
+/*
+** Generate code for a DELETE FROM statement.
+**
+**     DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
+**                 \________/       \________________/
+**                  pTabList              pWhere
+*/
+void sqlite3DeleteFrom(
+  Parse *pParse,         /* The parser context */
+  SrcList *pTabList,     /* The table from which we should delete things */
+  Expr *pWhere           /* The WHERE clause.  May be null */
+){
+  Vdbe *v;               /* The virtual database engine */
+  Table *pTab;           /* The table from which records will be deleted */
+  const char *zDb;       /* Name of database holding pTab */
+  int end, addr = 0;     /* A couple addresses of generated code */
+  int i;                 /* Loop counter */
+  WhereInfo *pWInfo;     /* Information about the WHERE clause */
+  Index *pIdx;           /* For looping over indices of the table */
+  int iCur;              /* VDBE Cursor number for pTab */
+  sqlite3 *db;           /* Main database structure */
+  AuthContext sContext;  /* Authorization context */
+  int oldIdx = -1;       /* Cursor for the OLD table of AFTER triggers */
+  NameContext sNC;       /* Name context to resolve expressions in */
+  int iDb;               /* Database number */
+  int memCnt = 0;        /* Memory cell used for change counting */
+
+#ifndef SQLITE_OMIT_TRIGGER
+  int isView;                  /* True if attempting to delete from a view */
+  int triggers_exist = 0;      /* True if any triggers exist */
+#endif
+  int iBeginAfterTrigger;      /* Address of after trigger program */
+  int iEndAfterTrigger;        /* Exit of after trigger program */
+  int iBeginBeforeTrigger;     /* Address of before trigger program */
+  int iEndBeforeTrigger;       /* Exit of before trigger program */
+  u32 old_col_mask = 0;        /* Mask of OLD.* columns in use */
+
+  sContext.pParse = 0;
+  db = pParse->db;
+  if( pParse->nErr || db->mallocFailed ){
+    goto delete_from_cleanup;
+  }
+  assert( pTabList->nSrc==1 );
+
+  /* Locate the table which we want to delete.  This table has to be
+  ** put in an SrcList structure because some of the subroutines we
+  ** will be calling are designed to work with multiple tables and expect
+  ** an SrcList* parameter instead of just a Table* parameter.
+  */
+  pTab = sqlite3SrcListLookup(pParse, pTabList);
+  if( pTab==0 )  goto delete_from_cleanup;
+
+  /* Figure out if we have any triggers and if the table being
+  ** deleted from is a view
+  */
+#ifndef SQLITE_OMIT_TRIGGER
+  triggers_exist = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0);
+  isView = pTab->pSelect!=0;
+#else
+# define triggers_exist 0
+# define isView 0
+#endif
+#ifdef SQLITE_OMIT_VIEW
+# undef isView
+# define isView 0
+#endif
+
+  if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
+    goto delete_from_cleanup;
+  }
+  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+  assert( iDb<db->nDb );
+  zDb = db->aDb[iDb].zName;
+  if( sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){
+    goto delete_from_cleanup;
+  }
+
+  /* If pTab is really a view, make sure it has been initialized.
+  */
+  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
+    goto delete_from_cleanup;
+  }
+
+  /* Allocate a cursor used to store the old.* data for a trigger.
+  */
+  if( triggers_exist ){ 
+    oldIdx = pParse->nTab++;
+  }
+
+  /* Assign  cursor number to the table and all its indices.
+  */
+  assert( pTabList->nSrc==1 );
+  iCur = pTabList->a[0].iCursor = pParse->nTab++;
+  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+    pParse->nTab++;
+  }
+
+  /* Start the view context
+  */
+  if( isView ){
+    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
+  }
+
+  /* Begin generating code.
+  */
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 ){
+    goto delete_from_cleanup;
+  }
+  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
+  sqlite3BeginWriteOperation(pParse, triggers_exist, iDb);
+
+  if( triggers_exist ){
+    int orconf = ((pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
+    int iGoto = sqlite3VdbeAddOp0(v, OP_Goto);
+    addr = sqlite3VdbeMakeLabel(v);
+
+    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
+    (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_BEFORE, pTab,
+        -1, oldIdx, orconf, addr, &old_col_mask, 0);
+    iEndBeforeTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
+
+    iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
+    (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_AFTER, pTab, -1,
+        oldIdx, orconf, addr, &old_col_mask, 0);
+    iEndAfterTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
+
+    sqlite3VdbeJumpHere(v, iGoto);
+  }
+
+  /* If we are trying to delete from a view, realize that view into
+  ** a ephemeral table.
+  */
+  if( isView ){
+    sqlite3MaterializeView(pParse, pTab->pSelect, pWhere, iCur);
+  }
+
+  /* Resolve the column names in the WHERE clause.
+  */
+  memset(&sNC, 0, sizeof(sNC));
+  sNC.pParse = pParse;
+  sNC.pSrcList = pTabList;
+  if( sqlite3ExprResolveNames(&sNC, pWhere) ){
+    goto delete_from_cleanup;
+  }
+
+  /* Initialize the counter of the number of rows deleted, if
+  ** we are counting rows.
+  */
+  if( db->flags & SQLITE_CountRows ){
+    memCnt = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt);
+  }
+
+  /* Special case: A DELETE without a WHERE clause deletes everything.
+  ** It is easier just to erase the whole table.  Note, however, that
+  ** this means that the row change count will be incorrect.
+  */
+  if( pWhere==0 && !triggers_exist && !IsVirtual(pTab) ){
+    if( db->flags & SQLITE_CountRows ){
+      /* If counting rows deleted, just count the total number of
+      ** entries in the table. */
+      int addr2;
+      if( !isView ){
+        sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
+      }
+      sqlite3VdbeAddOp2(v, OP_Rewind, iCur, sqlite3VdbeCurrentAddr(v)+2);
+      addr2 = sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
+      sqlite3VdbeAddOp2(v, OP_Next, iCur, addr2);
+      sqlite3VdbeAddOp1(v, OP_Close, iCur);
+    }
+    if( !isView ){
+      sqlite3VdbeAddOp2(v, OP_Clear, pTab->tnum, iDb);
+      if( !pParse->nested ){
+        sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
+      }
+      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+        assert( pIdx->pSchema==pTab->pSchema );
+        sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
+      }
+    }
+  } 
+  /* The usual case: There is a WHERE clause so we have to scan through
+  ** the table and pick which records to delete.
+  */
+  else{
+    int iRowid = ++pParse->nMem;    /* Used for storing rowid values. */
+
+    /* Begin the database scan
+    */
+    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0);
+    if( pWInfo==0 ) goto delete_from_cleanup;
+
+    /* Remember the rowid of every item to be deleted.
+    */
+    sqlite3VdbeAddOp2(v, IsVirtual(pTab) ? OP_VRowid : OP_Rowid, iCur, iRowid);
+    sqlite3VdbeAddOp1(v, OP_FifoWrite, iRowid);
+    if( db->flags & SQLITE_CountRows ){
+      sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
+    }
+
+    /* End the database scan loop.
+    */
+    sqlite3WhereEnd(pWInfo);
+
+    /* Open the pseudo-table used to store OLD if there are triggers.
+    */
+    if( triggers_exist ){
+      sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
+      sqlite3VdbeAddOp1(v, OP_OpenPseudo, oldIdx);
+    }
+
+    /* Delete every item whose key was written to the list during the
+    ** database scan.  We have to delete items after the scan is complete
+    ** because deleting an item can change the scan order.
+    */
+    end = sqlite3VdbeMakeLabel(v);
+
+    if( !isView ){
+      /* Open cursors for the table we are deleting from and 
+      ** all its indices.
+      */
+      sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite);
+    }
+
+    /* This is the beginning of the delete loop. If a trigger encounters
+    ** an IGNORE constraint, it jumps back to here.
+    */
+    if( triggers_exist ){
+      sqlite3VdbeResolveLabel(v, addr);
+    }
+    addr = sqlite3VdbeAddOp2(v, OP_FifoRead, iRowid, end);
+
+    if( triggers_exist ){
+      int iData = ++pParse->nMem;   /* For storing row data of OLD table */
+
+      /* If the record is no longer present in the table, jump to the
+      ** next iteration of the loop through the contents of the fifo.
+      */
+      sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, iRowid);
+
+      /* Populate the OLD.* pseudo-table */
+      if( old_col_mask ){
+        sqlite3VdbeAddOp2(v, OP_RowData, iCur, iData);
+      }else{
+        sqlite3VdbeAddOp2(v, OP_Null, 0, iData);
+      }
+      sqlite3VdbeAddOp3(v, OP_Insert, oldIdx, iData, iRowid);
+
+      /* Jump back and run the BEFORE triggers */
+      sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger);
+      sqlite3VdbeJumpHere(v, iEndBeforeTrigger);
+    }
+
+    if( !isView ){
+      /* Delete the row */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+      if( IsVirtual(pTab) ){
+        const char *pVtab = (const char *)pTab->pVtab;
+        sqlite3VtabMakeWritable(pParse, pTab);
+        sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVtab, P4_VTAB);
+      }else
+#endif
+      {
+        sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, pParse->nested==0);
+      }
+    }
+
+    /* If there are row triggers, close all cursors then invoke
+    ** the AFTER triggers
+    */
+    if( triggers_exist ){
+      /* Jump back and run the AFTER triggers */
+      sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger);
+      sqlite3VdbeJumpHere(v, iEndAfterTrigger);
+    }
+
+    /* End of the delete loop */
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
+    sqlite3VdbeResolveLabel(v, end);
+
+    /* Close the cursors after the loop if there are no row triggers */
+    if( !isView  && !IsVirtual(pTab) ){
+      for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
+        sqlite3VdbeAddOp2(v, OP_Close, iCur + i, pIdx->tnum);
+      }
+      sqlite3VdbeAddOp1(v, OP_Close, iCur);
+    }
+  }
+
+  /*
+  ** Return the number of rows that were deleted. If this routine is 
+  ** generating code because of a call to sqlite3NestedParse(), do not
+  ** invoke the callback function.
+  */
+  if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
+    sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1);
+    sqlite3VdbeSetNumCols(v, 1);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", P4_STATIC);
+  }
+
+delete_from_cleanup:
+  sqlite3AuthContextPop(&sContext);
+  sqlite3SrcListDelete(db, pTabList);
+  sqlite3ExprDelete(db, pWhere);
+  return;
+}
+
+/*
+** This routine generates VDBE code that causes a single row of a
+** single table to be deleted.
+**
+** The VDBE must be in a particular state when this routine is called.
+** These are the requirements:
+**
+**   1.  A read/write cursor pointing to pTab, the table containing the row
+**       to be deleted, must be opened as cursor number "base".
+**
+**   2.  Read/write cursors for all indices of pTab must be open as
+**       cursor number base+i for the i-th index.
+**
+**   3.  The record number of the row to be deleted must be stored in
+**       memory cell iRowid.
+**
+** This routine pops the top of the stack to remove the record number
+** and then generates code to remove both the table record and all index
+** entries that point to that record.
+*/
+void sqlite3GenerateRowDelete(
+  Parse *pParse,     /* Parsing context */
+  Table *pTab,       /* Table containing the row to be deleted */
+  int iCur,          /* Cursor number for the table */
+  int iRowid,        /* Memory cell that contains the rowid to delete */
+  int count          /* Increment the row change counter */
+){
+  int addr;
+  Vdbe *v;
+
+  v = pParse->pVdbe;
+  addr = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowid);
+  sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, 0);
+  sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
+  if( count ){
+    sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
+  }
+  sqlite3VdbeJumpHere(v, addr);
+}
+
+/*
+** This routine generates VDBE code that causes the deletion of all
+** index entries associated with a single row of a single table.
+**
+** The VDBE must be in a particular state when this routine is called.
+** These are the requirements:
+**
+**   1.  A read/write cursor pointing to pTab, the table containing the row
+**       to be deleted, must be opened as cursor number "iCur".
+**
+**   2.  Read/write cursors for all indices of pTab must be open as
+**       cursor number iCur+i for the i-th index.
+**
+**   3.  The "iCur" cursor must be pointing to the row that is to be
+**       deleted.
+*/
+void sqlite3GenerateRowIndexDelete(
+  Parse *pParse,     /* Parsing and code generating context */
+  Table *pTab,       /* Table containing the row to be deleted */
+  int iCur,          /* Cursor number for the table */
+  int *aRegIdx       /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
+){
+  int i;
+  Index *pIdx;
+  int r1;
+
+  for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
+    if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue;
+    r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0);
+    sqlite3VdbeAddOp3(pParse->pVdbe, OP_IdxDelete, iCur+i, r1,pIdx->nColumn+1);
+  }
+}
+
+/*
+** Generate code that will assemble an index key and put it in register
+** regOut.  The key with be for index pIdx which is an index on pTab.
+** iCur is the index of a cursor open on the pTab table and pointing to
+** the entry that needs indexing.
+**
+** Return a register number which is the first in a block of
+** registers that holds the elements of the index key.  The
+** block of registers has already been deallocated by the time
+** this routine returns.
+*/
+int sqlite3GenerateIndexKey(
+  Parse *pParse,     /* Parsing context */
+  Index *pIdx,       /* The index for which to generate a key */
+  int iCur,          /* Cursor number for the pIdx->pTable table */
+  int regOut,        /* Write the new index key to this register */
+  int doMakeRec      /* Run the OP_MakeRecord instruction if true */
+){
+  Vdbe *v = pParse->pVdbe;
+  int j;
+  Table *pTab = pIdx->pTable;
+  int regBase;
+  int nCol;
+
+  nCol = pIdx->nColumn;
+  regBase = sqlite3GetTempRange(pParse, nCol+1);
+  sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol);
+  for(j=0; j<nCol; j++){
+    int idx = pIdx->aiColumn[j];
+    if( idx==pTab->iPKey ){
+      sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j);
+    }else{
+      sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
+      sqlite3ColumnDefault(v, pTab, idx);
+    }
+  }
+  if( doMakeRec ){
+    sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut);
+    sqlite3IndexAffinityStr(v, pIdx);
+    sqlite3ExprCacheAffinityChange(pParse, regBase, nCol+1);
+  }
+  sqlite3ReleaseTempRange(pParse, regBase, nCol+1);
+  return regBase;
+}
+
+/* Make sure "isView" gets undefined in case this file becomes part of
+** the amalgamation - so that subsequent files do not see isView as a
+** macro. */
+#undef isView
diff --git a/third_party/sqlite/src/expr.c b/third_party/sqlite/src/expr.c
new file mode 100755
index 0000000..e8d8a1e
--- /dev/null
+++ b/third_party/sqlite/src/expr.c
@@ -0,0 +1,3586 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains routines used for analyzing expressions and
+** for generating VDBE code that evaluates expressions in SQLite.
+**
+** $Id: expr.c,v 1.387 2008/07/28 19:34:53 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+
+/*
+** Return the 'affinity' of the expression pExpr if any.
+**
+** If pExpr is a column, a reference to a column via an 'AS' alias,
+** or a sub-select with a column as the return value, then the 
+** affinity of that column is returned. Otherwise, 0x00 is returned,
+** indicating no affinity for the expression.
+**
+** i.e. the WHERE clause expresssions in the following statements all
+** have an affinity:
+**
+** CREATE TABLE t1(a);
+** SELECT * FROM t1 WHERE a;
+** SELECT a AS b FROM t1 WHERE b;
+** SELECT * FROM t1 WHERE (select a from t1);
+*/
+char sqlite3ExprAffinity(Expr *pExpr){
+  int op = pExpr->op;
+  if( op==TK_SELECT ){
+    return sqlite3ExprAffinity(pExpr->pSelect->pEList->a[0].pExpr);
+  }
+#ifndef SQLITE_OMIT_CAST
+  if( op==TK_CAST ){
+    return sqlite3AffinityType(&pExpr->token);
+  }
+#endif
+  return pExpr->affinity;
+}
+
+/*
+** Set the collating sequence for expression pExpr to be the collating
+** sequence named by pToken.   Return a pointer to the revised expression.
+** The collating sequence is marked as "explicit" using the EP_ExpCollate
+** flag.  An explicit collating sequence will override implicit
+** collating sequences.
+*/
+Expr *sqlite3ExprSetColl(Parse *pParse, Expr *pExpr, Token *pName){
+  char *zColl = 0;            /* Dequoted name of collation sequence */
+  CollSeq *pColl;
+  sqlite3 *db = pParse->db;
+  zColl = sqlite3NameFromToken(db, pName);
+  if( pExpr && zColl ){
+    pColl = sqlite3LocateCollSeq(pParse, zColl, -1);
+    if( pColl ){
+      pExpr->pColl = pColl;
+      pExpr->flags |= EP_ExpCollate;
+    }
+  }
+  sqlite3DbFree(db, zColl);
+  return pExpr;
+}
+
+/*
+** Return the default collation sequence for the expression pExpr. If
+** there is no default collation type, return 0.
+*/
+CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
+  CollSeq *pColl = 0;
+  if( pExpr ){
+    int op;
+    pColl = pExpr->pColl;
+    op = pExpr->op;
+    if( (op==TK_CAST || op==TK_UPLUS) && !pColl ){
+      return sqlite3ExprCollSeq(pParse, pExpr->pLeft);
+    }
+  }
+  if( sqlite3CheckCollSeq(pParse, pColl) ){ 
+    pColl = 0;
+  }
+  return pColl;
+}
+
+/*
+** pExpr is an operand of a comparison operator.  aff2 is the
+** type affinity of the other operand.  This routine returns the
+** type affinity that should be used for the comparison operator.
+*/
+char sqlite3CompareAffinity(Expr *pExpr, char aff2){
+  char aff1 = sqlite3ExprAffinity(pExpr);
+  if( aff1 && aff2 ){
+    /* Both sides of the comparison are columns. If one has numeric
+    ** affinity, use that. Otherwise use no affinity.
+    */
+    if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
+      return SQLITE_AFF_NUMERIC;
+    }else{
+      return SQLITE_AFF_NONE;
+    }
+  }else if( !aff1 && !aff2 ){
+    /* Neither side of the comparison is a column.  Compare the
+    ** results directly.
+    */
+    return SQLITE_AFF_NONE;
+  }else{
+    /* One side is a column, the other is not. Use the columns affinity. */
+    assert( aff1==0 || aff2==0 );
+    return (aff1 + aff2);
+  }
+}
+
+/*
+** pExpr is a comparison operator.  Return the type affinity that should
+** be applied to both operands prior to doing the comparison.
+*/
+static char comparisonAffinity(Expr *pExpr){
+  char aff;
+  assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
+          pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
+          pExpr->op==TK_NE );
+  assert( pExpr->pLeft );
+  aff = sqlite3ExprAffinity(pExpr->pLeft);
+  if( pExpr->pRight ){
+    aff = sqlite3CompareAffinity(pExpr->pRight, aff);
+  }
+  else if( pExpr->pSelect ){
+    aff = sqlite3CompareAffinity(pExpr->pSelect->pEList->a[0].pExpr, aff);
+  }
+  else if( !aff ){
+    aff = SQLITE_AFF_NONE;
+  }
+  return aff;
+}
+
+/*
+** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
+** idx_affinity is the affinity of an indexed column. Return true
+** if the index with affinity idx_affinity may be used to implement
+** the comparison in pExpr.
+*/
+int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
+  char aff = comparisonAffinity(pExpr);
+  switch( aff ){
+    case SQLITE_AFF_NONE:
+      return 1;
+    case SQLITE_AFF_TEXT:
+      return idx_affinity==SQLITE_AFF_TEXT;
+    default:
+      return sqlite3IsNumericAffinity(idx_affinity);
+  }
+}
+
+/*
+** Return the P5 value that should be used for a binary comparison
+** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
+*/
+static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
+  u8 aff = (char)sqlite3ExprAffinity(pExpr2);
+  aff = sqlite3CompareAffinity(pExpr1, aff) | jumpIfNull;
+  return aff;
+}
+
+/*
+** Return a pointer to the collation sequence that should be used by
+** a binary comparison operator comparing pLeft and pRight.
+**
+** If the left hand expression has a collating sequence type, then it is
+** used. Otherwise the collation sequence for the right hand expression
+** is used, or the default (BINARY) if neither expression has a collating
+** type.
+**
+** Argument pRight (but not pLeft) may be a null pointer. In this case,
+** it is not considered.
+*/
+CollSeq *sqlite3BinaryCompareCollSeq(
+  Parse *pParse, 
+  Expr *pLeft, 
+  Expr *pRight
+){
+  CollSeq *pColl;
+  assert( pLeft );
+  if( pLeft->flags & EP_ExpCollate ){
+    assert( pLeft->pColl );
+    pColl = pLeft->pColl;
+  }else if( pRight && pRight->flags & EP_ExpCollate ){
+    assert( pRight->pColl );
+    pColl = pRight->pColl;
+  }else{
+    pColl = sqlite3ExprCollSeq(pParse, pLeft);
+    if( !pColl ){
+      pColl = sqlite3ExprCollSeq(pParse, pRight);
+    }
+  }
+  return pColl;
+}
+
+/*
+** Generate the operands for a comparison operation.  Before
+** generating the code for each operand, set the EP_AnyAff
+** flag on the expression so that it will be able to used a
+** cached column value that has previously undergone an
+** affinity change.
+*/
+static void codeCompareOperands(
+  Parse *pParse,    /* Parsing and code generating context */
+  Expr *pLeft,      /* The left operand */
+  int *pRegLeft,    /* Register where left operand is stored */
+  int *pFreeLeft,   /* Free this register when done */
+  Expr *pRight,     /* The right operand */
+  int *pRegRight,   /* Register where right operand is stored */
+  int *pFreeRight   /* Write temp register for right operand there */
+){
+  while( pLeft->op==TK_UPLUS ) pLeft = pLeft->pLeft;
+  pLeft->flags |= EP_AnyAff;
+  *pRegLeft = sqlite3ExprCodeTemp(pParse, pLeft, pFreeLeft);
+  while( pRight->op==TK_UPLUS ) pRight = pRight->pLeft;
+  pRight->flags |= EP_AnyAff;
+  *pRegRight = sqlite3ExprCodeTemp(pParse, pRight, pFreeRight);
+}
+
+/*
+** Generate code for a comparison operator.
+*/
+static int codeCompare(
+  Parse *pParse,    /* The parsing (and code generating) context */
+  Expr *pLeft,      /* The left operand */
+  Expr *pRight,     /* The right operand */
+  int opcode,       /* The comparison opcode */
+  int in1, int in2, /* Register holding operands */
+  int dest,         /* Jump here if true.  */
+  int jumpIfNull    /* If true, jump if either operand is NULL */
+){
+  int p5;
+  int addr;
+  CollSeq *p4;
+
+  p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
+  p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
+  addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
+                           (void*)p4, P4_COLLSEQ);
+  sqlite3VdbeChangeP5(pParse->pVdbe, p5);
+  if( (p5 & SQLITE_AFF_MASK)!=SQLITE_AFF_NONE ){
+    sqlite3ExprCacheAffinityChange(pParse, in1, 1);
+    sqlite3ExprCacheAffinityChange(pParse, in2, 1);
+  }
+  return addr;
+}
+
+#if SQLITE_MAX_EXPR_DEPTH>0
+/*
+** Check that argument nHeight is less than or equal to the maximum
+** expression depth allowed. If it is not, leave an error message in
+** pParse.
+*/
+static int checkExprHeight(Parse *pParse, int nHeight){
+  int rc = SQLITE_OK;
+  int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
+  if( nHeight>mxHeight ){
+    sqlite3ErrorMsg(pParse, 
+       "Expression tree is too large (maximum depth %d)", mxHeight
+    );
+    rc = SQLITE_ERROR;
+  }
+  return rc;
+}
+
+/* The following three functions, heightOfExpr(), heightOfExprList()
+** and heightOfSelect(), are used to determine the maximum height
+** of any expression tree referenced by the structure passed as the
+** first argument.
+**
+** If this maximum height is greater than the current value pointed
+** to by pnHeight, the second parameter, then set *pnHeight to that
+** value.
+*/
+static void heightOfExpr(Expr *p, int *pnHeight){
+  if( p ){
+    if( p->nHeight>*pnHeight ){
+      *pnHeight = p->nHeight;
+    }
+  }
+}
+static void heightOfExprList(ExprList *p, int *pnHeight){
+  if( p ){
+    int i;
+    for(i=0; i<p->nExpr; i++){
+      heightOfExpr(p->a[i].pExpr, pnHeight);
+    }
+  }
+}
+static void heightOfSelect(Select *p, int *pnHeight){
+  if( p ){
+    heightOfExpr(p->pWhere, pnHeight);
+    heightOfExpr(p->pHaving, pnHeight);
+    heightOfExpr(p->pLimit, pnHeight);
+    heightOfExpr(p->pOffset, pnHeight);
+    heightOfExprList(p->pEList, pnHeight);
+    heightOfExprList(p->pGroupBy, pnHeight);
+    heightOfExprList(p->pOrderBy, pnHeight);
+    heightOfSelect(p->pPrior, pnHeight);
+  }
+}
+
+/*
+** Set the Expr.nHeight variable in the structure passed as an 
+** argument. An expression with no children, Expr.pList or 
+** Expr.pSelect member has a height of 1. Any other expression
+** has a height equal to the maximum height of any other 
+** referenced Expr plus one.
+*/
+static void exprSetHeight(Expr *p){
+  int nHeight = 0;
+  heightOfExpr(p->pLeft, &nHeight);
+  heightOfExpr(p->pRight, &nHeight);
+  heightOfExprList(p->pList, &nHeight);
+  heightOfSelect(p->pSelect, &nHeight);
+  p->nHeight = nHeight + 1;
+}
+
+/*
+** Set the Expr.nHeight variable using the exprSetHeight() function. If
+** the height is greater than the maximum allowed expression depth,
+** leave an error in pParse.
+*/
+void sqlite3ExprSetHeight(Parse *pParse, Expr *p){
+  exprSetHeight(p);
+  checkExprHeight(pParse, p->nHeight);
+}
+
+/*
+** Return the maximum height of any expression tree referenced
+** by the select statement passed as an argument.
+*/
+int sqlite3SelectExprHeight(Select *p){
+  int nHeight = 0;
+  heightOfSelect(p, &nHeight);
+  return nHeight;
+}
+#else
+  #define checkExprHeight(x,y)
+  #define exprSetHeight(y)
+#endif /* SQLITE_MAX_EXPR_DEPTH>0 */
+
+/*
+** Construct a new expression node and return a pointer to it.  Memory
+** for this node is obtained from sqlite3_malloc().  The calling function
+** is responsible for making sure the node eventually gets freed.
+*/
+Expr *sqlite3Expr(
+  sqlite3 *db,            /* Handle for sqlite3DbMallocZero() (may be null) */
+  int op,                 /* Expression opcode */
+  Expr *pLeft,            /* Left operand */
+  Expr *pRight,           /* Right operand */
+  const Token *pToken     /* Argument token */
+){
+  Expr *pNew;
+  pNew = sqlite3DbMallocZero(db, sizeof(Expr));
+  if( pNew==0 ){
+    /* When malloc fails, delete pLeft and pRight. Expressions passed to 
+    ** this function must always be allocated with sqlite3Expr() for this 
+    ** reason. 
+    */
+    sqlite3ExprDelete(db, pLeft);
+    sqlite3ExprDelete(db, pRight);
+    return 0;
+  }
+  pNew->op = op;
+  pNew->pLeft = pLeft;
+  pNew->pRight = pRight;
+  pNew->iAgg = -1;
+  pNew->span.z = (u8*)"";
+  if( pToken ){
+    assert( pToken->dyn==0 );
+    pNew->span = pNew->token = *pToken;
+  }else if( pLeft ){
+    if( pRight ){
+      if( pRight->span.dyn==0 && pLeft->span.dyn==0 ){
+        sqlite3ExprSpan(pNew, &pLeft->span, &pRight->span);
+      }
+      if( pRight->flags & EP_ExpCollate ){
+        pNew->flags |= EP_ExpCollate;
+        pNew->pColl = pRight->pColl;
+      }
+    }
+    if( pLeft->flags & EP_ExpCollate ){
+      pNew->flags |= EP_ExpCollate;
+      pNew->pColl = pLeft->pColl;
+    }
+  }
+
+  exprSetHeight(pNew);
+  return pNew;
+}
+
+/*
+** Works like sqlite3Expr() except that it takes an extra Parse*
+** argument and notifies the associated connection object if malloc fails.
+*/
+Expr *sqlite3PExpr(
+  Parse *pParse,          /* Parsing context */
+  int op,                 /* Expression opcode */
+  Expr *pLeft,            /* Left operand */
+  Expr *pRight,           /* Right operand */
+  const Token *pToken     /* Argument token */
+){
+  Expr *p = sqlite3Expr(pParse->db, op, pLeft, pRight, pToken);
+  if( p ){
+    checkExprHeight(pParse, p->nHeight);
+  }
+  return p;
+}
+
+/*
+** When doing a nested parse, you can include terms in an expression
+** that look like this:   #1 #2 ...  These terms refer to registers
+** in the virtual machine.  #N is the N-th register.
+**
+** This routine is called by the parser to deal with on of those terms.
+** It immediately generates code to store the value in a memory location.
+** The returns an expression that will code to extract the value from
+** that memory location as needed.
+*/
+Expr *sqlite3RegisterExpr(Parse *pParse, Token *pToken){
+  Vdbe *v = pParse->pVdbe;
+  Expr *p;
+  if( pParse->nested==0 ){
+    sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", pToken);
+    return sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
+  }
+  if( v==0 ) return 0;
+  p = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, pToken);
+  if( p==0 ){
+    return 0;  /* Malloc failed */
+  }
+  p->iTable = atoi((char*)&pToken->z[1]);
+  return p;
+}
+
+/*
+** Join two expressions using an AND operator.  If either expression is
+** NULL, then just return the other expression.
+*/
+Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){
+  if( pLeft==0 ){
+    return pRight;
+  }else if( pRight==0 ){
+    return pLeft;
+  }else{
+    return sqlite3Expr(db, TK_AND, pLeft, pRight, 0);
+  }
+}
+
+/*
+** Set the Expr.span field of the given expression to span all
+** text between the two given tokens.  Both tokens must be pointing
+** at the same string.
+*/
+void sqlite3ExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
+  assert( pRight!=0 );
+  assert( pLeft!=0 );
+  if( pExpr ){
+    pExpr->span.z = pLeft->z;
+    pExpr->span.n = pRight->n + (pRight->z - pLeft->z);
+  }
+}
+
+/*
+** Construct a new expression node for a function with multiple
+** arguments.
+*/
+Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){
+  Expr *pNew;
+  sqlite3 *db = pParse->db;
+  assert( pToken );
+  pNew = sqlite3DbMallocZero(db, sizeof(Expr) );
+  if( pNew==0 ){
+    sqlite3ExprListDelete(db, pList); /* Avoid leaking memory when malloc fails */
+    return 0;
+  }
+  pNew->op = TK_FUNCTION;
+  pNew->pList = pList;
+  assert( pToken->dyn==0 );
+  pNew->token = *pToken;
+  pNew->span = pNew->token;
+
+  sqlite3ExprSetHeight(pParse, pNew);
+  return pNew;
+}
+
+/*
+** Assign a variable number to an expression that encodes a wildcard
+** in the original SQL statement.  
+**
+** Wildcards consisting of a single "?" are assigned the next sequential
+** variable number.
+**
+** Wildcards of the form "?nnn" are assigned the number "nnn".  We make
+** sure "nnn" is not too be to avoid a denial of service attack when
+** the SQL statement comes from an external source.
+**
+** Wildcards of the form ":aaa" or "$aaa" are assigned the same number
+** as the previous instance of the same wildcard.  Or if this is the first
+** instance of the wildcard, the next sequenial variable number is
+** assigned.
+*/
+void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
+  Token *pToken;
+  sqlite3 *db = pParse->db;
+
+  if( pExpr==0 ) return;
+  pToken = &pExpr->token;
+  assert( pToken->n>=1 );
+  assert( pToken->z!=0 );
+  assert( pToken->z[0]!=0 );
+  if( pToken->n==1 ){
+    /* Wildcard of the form "?".  Assign the next variable number */
+    pExpr->iTable = ++pParse->nVar;
+  }else if( pToken->z[0]=='?' ){
+    /* Wildcard of the form "?nnn".  Convert "nnn" to an integer and
+    ** use it as the variable number */
+    int i;
+    pExpr->iTable = i = atoi((char*)&pToken->z[1]);
+    testcase( i==0 );
+    testcase( i==1 );
+    testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
+    testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
+    if( i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
+      sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
+          db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
+    }
+    if( i>pParse->nVar ){
+      pParse->nVar = i;
+    }
+  }else{
+    /* Wildcards of the form ":aaa" or "$aaa".  Reuse the same variable
+    ** number as the prior appearance of the same name, or if the name
+    ** has never appeared before, reuse the same variable number
+    */
+    int i, n;
+    n = pToken->n;
+    for(i=0; i<pParse->nVarExpr; i++){
+      Expr *pE;
+      if( (pE = pParse->apVarExpr[i])!=0
+          && pE->token.n==n
+          && memcmp(pE->token.z, pToken->z, n)==0 ){
+        pExpr->iTable = pE->iTable;
+        break;
+      }
+    }
+    if( i>=pParse->nVarExpr ){
+      pExpr->iTable = ++pParse->nVar;
+      if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){
+        pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10;
+        pParse->apVarExpr =
+            sqlite3DbReallocOrFree(
+              db,
+              pParse->apVarExpr,
+              pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0])
+            );
+      }
+      if( !db->mallocFailed ){
+        assert( pParse->apVarExpr!=0 );
+        pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
+      }
+    }
+  } 
+  if( !pParse->nErr && pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
+    sqlite3ErrorMsg(pParse, "too many SQL variables");
+  }
+}
+
+/*
+** Recursively delete an expression tree.
+*/
+void sqlite3ExprDelete(sqlite3 *db, Expr *p){
+  if( p==0 ) return;
+  if( p->span.dyn ) sqlite3DbFree(db, (char*)p->span.z);
+  if( p->token.dyn ) sqlite3DbFree(db, (char*)p->token.z);
+  sqlite3ExprDelete(db, p->pLeft);
+  sqlite3ExprDelete(db, p->pRight);
+  sqlite3ExprListDelete(db, p->pList);
+  sqlite3SelectDelete(db, p->pSelect);
+  sqlite3DbFree(db, p);
+}
+
+/*
+** The Expr.token field might be a string literal that is quoted.
+** If so, remove the quotation marks.
+*/
+void sqlite3DequoteExpr(sqlite3 *db, Expr *p){
+  if( ExprHasAnyProperty(p, EP_Dequoted) ){
+    return;
+  }
+  ExprSetProperty(p, EP_Dequoted);
+  if( p->token.dyn==0 ){
+    sqlite3TokenCopy(db, &p->token, &p->token);
+  }
+  sqlite3Dequote((char*)p->token.z);
+}
+
+
+/*
+** The following group of routines make deep copies of expressions,
+** expression lists, ID lists, and select statements.  The copies can
+** be deleted (by being passed to their respective ...Delete() routines)
+** without effecting the originals.
+**
+** The expression list, ID, and source lists return by sqlite3ExprListDup(),
+** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded 
+** by subsequent calls to sqlite*ListAppend() routines.
+**
+** Any tables that the SrcList might point to are not duplicated.
+*/
+Expr *sqlite3ExprDup(sqlite3 *db, Expr *p){
+  Expr *pNew;
+  if( p==0 ) return 0;
+  pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
+  if( pNew==0 ) return 0;
+  memcpy(pNew, p, sizeof(*pNew));
+  if( p->token.z!=0 ){
+    pNew->token.z = (u8*)sqlite3DbStrNDup(db, (char*)p->token.z, p->token.n);
+    pNew->token.dyn = 1;
+  }else{
+    assert( pNew->token.z==0 );
+  }
+  pNew->span.z = 0;
+  pNew->pLeft = sqlite3ExprDup(db, p->pLeft);
+  pNew->pRight = sqlite3ExprDup(db, p->pRight);
+  pNew->pList = sqlite3ExprListDup(db, p->pList);
+  pNew->pSelect = sqlite3SelectDup(db, p->pSelect);
+  return pNew;
+}
+void sqlite3TokenCopy(sqlite3 *db, Token *pTo, Token *pFrom){
+  if( pTo->dyn ) sqlite3DbFree(db, (char*)pTo->z);
+  if( pFrom->z ){
+    pTo->n = pFrom->n;
+    pTo->z = (u8*)sqlite3DbStrNDup(db, (char*)pFrom->z, pFrom->n);
+    pTo->dyn = 1;
+  }else{
+    pTo->z = 0;
+  }
+}
+ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p){
+  ExprList *pNew;
+  struct ExprList_item *pItem, *pOldItem;
+  int i;
+  if( p==0 ) return 0;
+  pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
+  if( pNew==0 ) return 0;
+  pNew->iECursor = 0;
+  pNew->nExpr = pNew->nAlloc = p->nExpr;
+  pNew->a = pItem = sqlite3DbMallocRaw(db,  p->nExpr*sizeof(p->a[0]) );
+  if( pItem==0 ){
+    sqlite3DbFree(db, pNew);
+    return 0;
+  } 
+  pOldItem = p->a;
+  for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
+    Expr *pNewExpr, *pOldExpr;
+    pItem->pExpr = pNewExpr = sqlite3ExprDup(db, pOldExpr = pOldItem->pExpr);
+    if( pOldExpr->span.z!=0 && pNewExpr ){
+      /* Always make a copy of the span for top-level expressions in the
+      ** expression list.  The logic in SELECT processing that determines
+      ** the names of columns in the result set needs this information */
+      sqlite3TokenCopy(db, &pNewExpr->span, &pOldExpr->span);
+    }
+    assert( pNewExpr==0 || pNewExpr->span.z!=0 
+            || pOldExpr->span.z==0
+            || db->mallocFailed );
+    pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
+    pItem->sortOrder = pOldItem->sortOrder;
+    pItem->isAgg = pOldItem->isAgg;
+    pItem->done = 0;
+  }
+  return pNew;
+}
+
+/*
+** If cursors, triggers, views and subqueries are all omitted from
+** the build, then none of the following routines, except for 
+** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
+** called with a NULL argument.
+*/
+#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
+ || !defined(SQLITE_OMIT_SUBQUERY)
+SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p){
+  SrcList *pNew;
+  int i;
+  int nByte;
+  if( p==0 ) return 0;
+  nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
+  pNew = sqlite3DbMallocRaw(db, nByte );
+  if( pNew==0 ) return 0;
+  pNew->nSrc = pNew->nAlloc = p->nSrc;
+  for(i=0; i<p->nSrc; i++){
+    struct SrcList_item *pNewItem = &pNew->a[i];
+    struct SrcList_item *pOldItem = &p->a[i];
+    Table *pTab;
+    pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
+    pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
+    pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
+    pNewItem->jointype = pOldItem->jointype;
+    pNewItem->iCursor = pOldItem->iCursor;
+    pNewItem->isPopulated = pOldItem->isPopulated;
+    pTab = pNewItem->pTab = pOldItem->pTab;
+    if( pTab ){
+      pTab->nRef++;
+    }
+    pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect);
+    pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn);
+    pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);
+    pNewItem->colUsed = pOldItem->colUsed;
+  }
+  return pNew;
+}
+IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
+  IdList *pNew;
+  int i;
+  if( p==0 ) return 0;
+  pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
+  if( pNew==0 ) return 0;
+  pNew->nId = pNew->nAlloc = p->nId;
+  pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
+  if( pNew->a==0 ){
+    sqlite3DbFree(db, pNew);
+    return 0;
+  }
+  for(i=0; i<p->nId; i++){
+    struct IdList_item *pNewItem = &pNew->a[i];
+    struct IdList_item *pOldItem = &p->a[i];
+    pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
+    pNewItem->idx = pOldItem->idx;
+  }
+  return pNew;
+}
+Select *sqlite3SelectDup(sqlite3 *db, Select *p){
+  Select *pNew;
+  if( p==0 ) return 0;
+  pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
+  if( pNew==0 ) return 0;
+  pNew->isDistinct = p->isDistinct;
+  pNew->pEList = sqlite3ExprListDup(db, p->pEList);
+  pNew->pSrc = sqlite3SrcListDup(db, p->pSrc);
+  pNew->pWhere = sqlite3ExprDup(db, p->pWhere);
+  pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy);
+  pNew->pHaving = sqlite3ExprDup(db, p->pHaving);
+  pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy);
+  pNew->op = p->op;
+  pNew->pPrior = sqlite3SelectDup(db, p->pPrior);
+  pNew->pLimit = sqlite3ExprDup(db, p->pLimit);
+  pNew->pOffset = sqlite3ExprDup(db, p->pOffset);
+  pNew->iLimit = 0;
+  pNew->iOffset = 0;
+  pNew->isResolved = p->isResolved;
+  pNew->isAgg = p->isAgg;
+  pNew->usesEphm = 0;
+  pNew->disallowOrderBy = 0;
+  pNew->pRightmost = 0;
+  pNew->addrOpenEphm[0] = -1;
+  pNew->addrOpenEphm[1] = -1;
+  pNew->addrOpenEphm[2] = -1;
+  return pNew;
+}
+#else
+Select *sqlite3SelectDup(sqlite3 *db, Select *p){
+  assert( p==0 );
+  return 0;
+}
+#endif
+
+
+/*
+** Add a new element to the end of an expression list.  If pList is
+** initially NULL, then create a new expression list.
+*/
+ExprList *sqlite3ExprListAppend(
+  Parse *pParse,          /* Parsing context */
+  ExprList *pList,        /* List to which to append. Might be NULL */
+  Expr *pExpr,            /* Expression to be appended */
+  Token *pName            /* AS keyword for the expression */
+){
+  sqlite3 *db = pParse->db;
+  if( pList==0 ){
+    pList = sqlite3DbMallocZero(db, sizeof(ExprList) );
+    if( pList==0 ){
+      goto no_mem;
+    }
+    assert( pList->nAlloc==0 );
+  }
+  if( pList->nAlloc<=pList->nExpr ){
+    struct ExprList_item *a;
+    int n = pList->nAlloc*2 + 4;
+    a = sqlite3DbRealloc(db, pList->a, n*sizeof(pList->a[0]));
+    if( a==0 ){
+      goto no_mem;
+    }
+    pList->a = a;
+    pList->nAlloc = n;
+  }
+  assert( pList->a!=0 );
+  if( pExpr || pName ){
+    struct ExprList_item *pItem = &pList->a[pList->nExpr++];
+    memset(pItem, 0, sizeof(*pItem));
+    pItem->zName = sqlite3NameFromToken(db, pName);
+    pItem->pExpr = pExpr;
+  }
+  return pList;
+
+no_mem:     
+  /* Avoid leaking memory if malloc has failed. */
+  sqlite3ExprDelete(db, pExpr);
+  sqlite3ExprListDelete(db, pList);
+  return 0;
+}
+
+/*
+** If the expression list pEList contains more than iLimit elements,
+** leave an error message in pParse.
+*/
+void sqlite3ExprListCheckLength(
+  Parse *pParse,
+  ExprList *pEList,
+  const char *zObject
+){
+  int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN];
+  testcase( pEList && pEList->nExpr==mx );
+  testcase( pEList && pEList->nExpr==mx+1 );
+  if( pEList && pEList->nExpr>mx ){
+    sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
+  }
+}
+
+/*
+** Delete an entire expression list.
+*/
+void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
+  int i;
+  struct ExprList_item *pItem;
+  if( pList==0 ) return;
+  assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
+  assert( pList->nExpr<=pList->nAlloc );
+  for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
+    sqlite3ExprDelete(db, pItem->pExpr);
+    sqlite3DbFree(db, pItem->zName);
+  }
+  sqlite3DbFree(db, pList->a);
+  sqlite3DbFree(db, pList);
+}
+
+/*
+** Walk an expression tree.  Call xFunc for each node visited.  xFunc
+** is called on the node before xFunc is called on the nodes children.
+**
+** The return value from xFunc determines whether the tree walk continues.
+** 0 means continue walking the tree.  1 means do not walk children
+** of the current node but continue with siblings.  2 means abandon
+** the tree walk completely.
+**
+** The return value from this routine is 1 to abandon the tree walk
+** and 0 to continue.
+**
+** NOTICE:  This routine does *not* descend into subqueries.
+*/
+static int walkExprList(ExprList *, int (*)(void *, Expr*), void *);
+static int walkExprTree(Expr *pExpr, int (*xFunc)(void*,Expr*), void *pArg){
+  int rc;
+  if( pExpr==0 ) return 0;
+  rc = (*xFunc)(pArg, pExpr);
+  if( rc==0 ){
+    if( walkExprTree(pExpr->pLeft, xFunc, pArg) ) return 1;
+    if( walkExprTree(pExpr->pRight, xFunc, pArg) ) return 1;
+    if( walkExprList(pExpr->pList, xFunc, pArg) ) return 1;
+  }
+  return rc>1;
+}
+
+/*
+** Call walkExprTree() for every expression in list p.
+*/
+static int walkExprList(ExprList *p, int (*xFunc)(void *, Expr*), void *pArg){
+  int i;
+  struct ExprList_item *pItem;
+  if( !p ) return 0;
+  for(i=p->nExpr, pItem=p->a; i>0; i--, pItem++){
+    if( walkExprTree(pItem->pExpr, xFunc, pArg) ) return 1;
+  }
+  return 0;
+}
+
+/*
+** Call walkExprTree() for every expression in Select p, not including
+** expressions that are part of sub-selects in any FROM clause or the LIMIT
+** or OFFSET expressions..
+*/
+static int walkSelectExpr(Select *p, int (*xFunc)(void *, Expr*), void *pArg){
+  walkExprList(p->pEList, xFunc, pArg);
+  walkExprTree(p->pWhere, xFunc, pArg);
+  walkExprList(p->pGroupBy, xFunc, pArg);
+  walkExprTree(p->pHaving, xFunc, pArg);
+  walkExprList(p->pOrderBy, xFunc, pArg);
+  if( p->pPrior ){
+    walkSelectExpr(p->pPrior, xFunc, pArg);
+  }
+  return 0;
+}
+
+
+/*
+** This routine is designed as an xFunc for walkExprTree().
+**
+** pArg is really a pointer to an integer.  If we can tell by looking
+** at pExpr that the expression that contains pExpr is not a constant
+** expression, then set *pArg to 0 and return 2 to abandon the tree walk.
+** If pExpr does does not disqualify the expression from being a constant
+** then do nothing.
+**
+** After walking the whole tree, if no nodes are found that disqualify
+** the expression as constant, then we assume the whole expression
+** is constant.  See sqlite3ExprIsConstant() for additional information.
+*/
+static int exprNodeIsConstant(void *pArg, Expr *pExpr){
+  int *pN = (int*)pArg;
+
+  /* If *pArg is 3 then any term of the expression that comes from
+  ** the ON or USING clauses of a join disqualifies the expression
+  ** from being considered constant. */
+  if( (*pN)==3 && ExprHasAnyProperty(pExpr, EP_FromJoin) ){
+    *pN = 0;
+    return 2;
+  }
+
+  switch( pExpr->op ){
+    /* Consider functions to be constant if all their arguments are constant
+    ** and *pArg==2 */
+    case TK_FUNCTION:
+      if( (*pN)==2 ) return 0;
+      /* Fall through */
+    case TK_ID:
+    case TK_COLUMN:
+    case TK_DOT:
+    case TK_AGG_FUNCTION:
+    case TK_AGG_COLUMN:
+#ifndef SQLITE_OMIT_SUBQUERY
+    case TK_SELECT:
+    case TK_EXISTS:
+      testcase( pExpr->op==TK_SELECT );
+      testcase( pExpr->op==TK_EXISTS );
+#endif
+      testcase( pExpr->op==TK_ID );
+      testcase( pExpr->op==TK_COLUMN );
+      testcase( pExpr->op==TK_DOT );
+      testcase( pExpr->op==TK_AGG_FUNCTION );
+      testcase( pExpr->op==TK_AGG_COLUMN );
+      *pN = 0;
+      return 2;
+    case TK_IN:
+      if( pExpr->pSelect ){
+        *pN = 0;
+        return 2;
+      }
+    default:
+      return 0;
+  }
+}
+
+/*
+** Walk an expression tree.  Return 1 if the expression is constant
+** and 0 if it involves variables or function calls.
+**
+** For the purposes of this function, a double-quoted string (ex: "abc")
+** is considered a variable but a single-quoted string (ex: 'abc') is
+** a constant.
+*/
+int sqlite3ExprIsConstant(Expr *p){
+  int isConst = 1;
+  walkExprTree(p, exprNodeIsConstant, &isConst);
+  return isConst;
+}
+
+/*
+** Walk an expression tree.  Return 1 if the expression is constant
+** that does no originate from the ON or USING clauses of a join.
+** Return 0 if it involves variables or function calls or terms from
+** an ON or USING clause.
+*/
+int sqlite3ExprIsConstantNotJoin(Expr *p){
+  int isConst = 3;
+  walkExprTree(p, exprNodeIsConstant, &isConst);
+  return isConst!=0;
+}
+
+/*
+** Walk an expression tree.  Return 1 if the expression is constant
+** or a function call with constant arguments.  Return and 0 if there
+** are any variables.
+**
+** For the purposes of this function, a double-quoted string (ex: "abc")
+** is considered a variable but a single-quoted string (ex: 'abc') is
+** a constant.
+*/
+int sqlite3ExprIsConstantOrFunction(Expr *p){
+  int isConst = 2;
+  walkExprTree(p, exprNodeIsConstant, &isConst);
+  return isConst!=0;
+}
+
+/*
+** If the expression p codes a constant integer that is small enough
+** to fit in a 32-bit integer, return 1 and put the value of the integer
+** in *pValue.  If the expression is not an integer or if it is too big
+** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
+*/
+int sqlite3ExprIsInteger(Expr *p, int *pValue){
+  int rc = 0;
+  if( p->flags & EP_IntValue ){
+    *pValue = p->iTable;
+    return 1;
+  }
+  switch( p->op ){
+    case TK_INTEGER: {
+      rc = sqlite3GetInt32((char*)p->token.z, pValue);
+      break;
+    }
+    case TK_UPLUS: {
+      rc = sqlite3ExprIsInteger(p->pLeft, pValue);
+      break;
+    }
+    case TK_UMINUS: {
+      int v;
+      if( sqlite3ExprIsInteger(p->pLeft, &v) ){
+        *pValue = -v;
+        rc = 1;
+      }
+      break;
+    }
+    default: break;
+  }
+  if( rc ){
+    p->op = TK_INTEGER;
+    p->flags |= EP_IntValue;
+    p->iTable = *pValue;
+  }
+  return rc;
+}
+
+/*
+** Return TRUE if the given string is a row-id column name.
+*/
+int sqlite3IsRowid(const char *z){
+  if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
+  if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
+  if( sqlite3StrICmp(z, "OID")==0 ) return 1;
+  return 0;
+}
+
+/*
+** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
+** that name in the set of source tables in pSrcList and make the pExpr 
+** expression node refer back to that source column.  The following changes
+** are made to pExpr:
+**
+**    pExpr->iDb           Set the index in db->aDb[] of the database holding
+**                         the table.
+**    pExpr->iTable        Set to the cursor number for the table obtained
+**                         from pSrcList.
+**    pExpr->iColumn       Set to the column number within the table.
+**    pExpr->op            Set to TK_COLUMN.
+**    pExpr->pLeft         Any expression this points to is deleted
+**    pExpr->pRight        Any expression this points to is deleted.
+**
+** The pDbToken is the name of the database (the "X").  This value may be
+** NULL meaning that name is of the form Y.Z or Z.  Any available database
+** can be used.  The pTableToken is the name of the table (the "Y").  This
+** value can be NULL if pDbToken is also NULL.  If pTableToken is NULL it
+** means that the form of the name is Z and that columns from any table
+** can be used.
+**
+** If the name cannot be resolved unambiguously, leave an error message
+** in pParse and return non-zero.  Return zero on success.
+*/
+static int lookupName(
+  Parse *pParse,       /* The parsing context */
+  Token *pDbToken,     /* Name of the database containing table, or NULL */
+  Token *pTableToken,  /* Name of table containing column, or NULL */
+  Token *pColumnToken, /* Name of the column. */
+  NameContext *pNC,    /* The name context used to resolve the name */
+  Expr *pExpr          /* Make this EXPR node point to the selected column */
+){
+  char *zDb = 0;       /* Name of the database.  The "X" in X.Y.Z */
+  char *zTab = 0;      /* Name of the table.  The "Y" in X.Y.Z or Y.Z */
+  char *zCol = 0;      /* Name of the column.  The "Z" */
+  int i, j;            /* Loop counters */
+  int cnt = 0;         /* Number of matching column names */
+  int cntTab = 0;      /* Number of matching table names */
+  sqlite3 *db = pParse->db;  /* The database */
+  struct SrcList_item *pItem;       /* Use for looping over pSrcList items */
+  struct SrcList_item *pMatch = 0;  /* The matching pSrcList item */
+  NameContext *pTopNC = pNC;        /* First namecontext in the list */
+  Schema *pSchema = 0;              /* Schema of the expression */
+
+  assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */
+  zDb = sqlite3NameFromToken(db, pDbToken);
+  zTab = sqlite3NameFromToken(db, pTableToken);
+  zCol = sqlite3NameFromToken(db, pColumnToken);
+  if( db->mallocFailed ){
+    goto lookupname_end;
+  }
+
+  pExpr->iTable = -1;
+  while( pNC && cnt==0 ){
+    ExprList *pEList;
+    SrcList *pSrcList = pNC->pSrcList;
+
+    if( pSrcList ){
+      for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
+        Table *pTab;
+        int iDb;
+        Column *pCol;
+  
+        pTab = pItem->pTab;
+        assert( pTab!=0 );
+        iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+        assert( pTab->nCol>0 );
+        if( zTab ){
+          if( pItem->zAlias ){
+            char *zTabName = pItem->zAlias;
+            if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
+          }else{
+            char *zTabName = pTab->zName;
+            if( zTabName==0 || sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
+            if( zDb!=0 && sqlite3StrICmp(db->aDb[iDb].zName, zDb)!=0 ){
+              continue;
+            }
+          }
+        }
+        if( 0==(cntTab++) ){
+          pExpr->iTable = pItem->iCursor;
+          pSchema = pTab->pSchema;
+          pMatch = pItem;
+        }
+        for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
+          if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
+            const char *zColl = pTab->aCol[j].zColl;
+            IdList *pUsing;
+            cnt++;
+            pExpr->iTable = pItem->iCursor;
+            pMatch = pItem;
+            pSchema = pTab->pSchema;
+            /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
+            pExpr->iColumn = j==pTab->iPKey ? -1 : j;
+            pExpr->affinity = pTab->aCol[j].affinity;
+            if( (pExpr->flags & EP_ExpCollate)==0 ){
+              pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
+            }
+            if( i<pSrcList->nSrc-1 ){
+              if( pItem[1].jointype & JT_NATURAL ){
+                /* If this match occurred in the left table of a natural join,
+                ** then skip the right table to avoid a duplicate match */
+                pItem++;
+                i++;
+              }else if( (pUsing = pItem[1].pUsing)!=0 ){
+                /* If this match occurs on a column that is in the USING clause
+                ** of a join, skip the search of the right table of the join
+                ** to avoid a duplicate match there. */
+                int k;
+                for(k=0; k<pUsing->nId; k++){
+                  if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ){
+                    pItem++;
+                    i++;
+                    break;
+                  }
+                }
+              }
+            }
+            break;
+          }
+        }
+      }
+    }
+
+#ifndef SQLITE_OMIT_TRIGGER
+    /* If we have not already resolved the name, then maybe 
+    ** it is a new.* or old.* trigger argument reference
+    */
+    if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){
+      TriggerStack *pTriggerStack = pParse->trigStack;
+      Table *pTab = 0;
+      u32 *piColMask;
+      if( pTriggerStack->newIdx != -1 && sqlite3StrICmp("new", zTab) == 0 ){
+        pExpr->iTable = pTriggerStack->newIdx;
+        assert( pTriggerStack->pTab );
+        pTab = pTriggerStack->pTab;
+        piColMask = &(pTriggerStack->newColMask);
+      }else if( pTriggerStack->oldIdx != -1 && sqlite3StrICmp("old", zTab)==0 ){
+        pExpr->iTable = pTriggerStack->oldIdx;
+        assert( pTriggerStack->pTab );
+        pTab = pTriggerStack->pTab;
+        piColMask = &(pTriggerStack->oldColMask);
+      }
+
+      if( pTab ){ 
+        int iCol;
+        Column *pCol = pTab->aCol;
+
+        pSchema = pTab->pSchema;
+        cntTab++;
+        for(iCol=0; iCol < pTab->nCol; iCol++, pCol++) {
+          if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
+            const char *zColl = pTab->aCol[iCol].zColl;
+            cnt++;
+            pExpr->iColumn = iCol==pTab->iPKey ? -1 : iCol;
+            pExpr->affinity = pTab->aCol[iCol].affinity;
+            if( (pExpr->flags & EP_ExpCollate)==0 ){
+              pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
+            }
+            pExpr->pTab = pTab;
+            if( iCol>=0 ){
+              testcase( iCol==31 );
+              testcase( iCol==32 );
+              *piColMask |= ((u32)1<<iCol) | (iCol>=32?0xffffffff:0);
+            }
+            break;
+          }
+        }
+      }
+    }
+#endif /* !defined(SQLITE_OMIT_TRIGGER) */
+
+    /*
+    ** Perhaps the name is a reference to the ROWID
+    */
+    if( cnt==0 && cntTab==1 && sqlite3IsRowid(zCol) ){
+      cnt = 1;
+      pExpr->iColumn = -1;
+      pExpr->affinity = SQLITE_AFF_INTEGER;
+    }
+
+    /*
+    ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z
+    ** might refer to an result-set alias.  This happens, for example, when
+    ** we are resolving names in the WHERE clause of the following command:
+    **
+    **     SELECT a+b AS x FROM table WHERE x<10;
+    **
+    ** In cases like this, replace pExpr with a copy of the expression that
+    ** forms the result set entry ("a+b" in the example) and return immediately.
+    ** Note that the expression in the result set should have already been
+    ** resolved by the time the WHERE clause is resolved.
+    */
+    if( cnt==0 && (pEList = pNC->pEList)!=0 && zTab==0 ){
+      for(j=0; j<pEList->nExpr; j++){
+        char *zAs = pEList->a[j].zName;
+        if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
+          Expr *pDup, *pOrig;
+          assert( pExpr->pLeft==0 && pExpr->pRight==0 );
+          assert( pExpr->pList==0 );
+          assert( pExpr->pSelect==0 );
+          pOrig = pEList->a[j].pExpr;
+          if( !pNC->allowAgg && ExprHasProperty(pOrig, EP_Agg) ){
+            sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
+            sqlite3DbFree(db, zCol);
+            return 2;
+          }
+          pDup = sqlite3ExprDup(db, pOrig);
+          if( pExpr->flags & EP_ExpCollate ){
+            pDup->pColl = pExpr->pColl;
+            pDup->flags |= EP_ExpCollate;
+          }
+          if( pExpr->span.dyn ) sqlite3DbFree(db, (char*)pExpr->span.z);
+          if( pExpr->token.dyn ) sqlite3DbFree(db, (char*)pExpr->token.z);
+          memcpy(pExpr, pDup, sizeof(*pExpr));
+          sqlite3DbFree(db, pDup);
+          cnt = 1;
+          pMatch = 0;
+          assert( zTab==0 && zDb==0 );
+          goto lookupname_end_2;
+        }
+      } 
+    }
+
+    /* Advance to the next name context.  The loop will exit when either
+    ** we have a match (cnt>0) or when we run out of name contexts.
+    */
+    if( cnt==0 ){
+      pNC = pNC->pNext;
+    }
+  }
+
+  /*
+  ** If X and Y are NULL (in other words if only the column name Z is
+  ** supplied) and the value of Z is enclosed in double-quotes, then
+  ** Z is a string literal if it doesn't match any column names.  In that
+  ** case, we need to return right away and not make any changes to
+  ** pExpr.
+  **
+  ** Because no reference was made to outer contexts, the pNC->nRef
+  ** fields are not changed in any context.
+  */
+  if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){
+    sqlite3DbFree(db, zCol);
+    return 0;
+  }
+
+  /*
+  ** cnt==0 means there was not match.  cnt>1 means there were two or
+  ** more matches.  Either way, we have an error.
+  */
+  if( cnt!=1 ){
+    const char *zErr;
+    zErr = cnt==0 ? "no such column" : "ambiguous column name";
+    if( zDb ){
+      sqlite3ErrorMsg(pParse, "%s: %s.%s.%s", zErr, zDb, zTab, zCol);
+    }else if( zTab ){
+      sqlite3ErrorMsg(pParse, "%s: %s.%s", zErr, zTab, zCol);
+    }else{
+      sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol);
+    }
+    pTopNC->nErr++;
+  }
+
+  /* If a column from a table in pSrcList is referenced, then record
+  ** this fact in the pSrcList.a[].colUsed bitmask.  Column 0 causes
+  ** bit 0 to be set.  Column 1 sets bit 1.  And so forth.  If the
+  ** column number is greater than the number of bits in the bitmask
+  ** then set the high-order bit of the bitmask.
+  */
+  if( pExpr->iColumn>=0 && pMatch!=0 ){
+    int n = pExpr->iColumn;
+    testcase( n==sizeof(Bitmask)*8-1 );
+    if( n>=sizeof(Bitmask)*8 ){
+      n = sizeof(Bitmask)*8-1;
+    }
+    assert( pMatch->iCursor==pExpr->iTable );
+    pMatch->colUsed |= ((Bitmask)1)<<n;
+  }
+
+lookupname_end:
+  /* Clean up and return
+  */
+  sqlite3DbFree(db, zDb);
+  sqlite3DbFree(db, zTab);
+  sqlite3ExprDelete(db, pExpr->pLeft);
+  pExpr->pLeft = 0;
+  sqlite3ExprDelete(db, pExpr->pRight);
+  pExpr->pRight = 0;
+  pExpr->op = TK_COLUMN;
+lookupname_end_2:
+  sqlite3DbFree(db, zCol);
+  if( cnt==1 ){
+    assert( pNC!=0 );
+    sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
+    if( pMatch && !pMatch->pSelect ){
+      pExpr->pTab = pMatch->pTab;
+    }
+    /* Increment the nRef value on all name contexts from TopNC up to
+    ** the point where the name matched. */
+    for(;;){
+      assert( pTopNC!=0 );
+      pTopNC->nRef++;
+      if( pTopNC==pNC ) break;
+      pTopNC = pTopNC->pNext;
+    }
+    return 0;
+  } else {
+    return 1;
+  }
+}
+
+/*
+** This routine is designed as an xFunc for walkExprTree().
+**
+** Resolve symbolic names into TK_COLUMN operators for the current
+** node in the expression tree.  Return 0 to continue the search down
+** the tree or 2 to abort the tree walk.
+**
+** This routine also does error checking and name resolution for
+** function names.  The operator for aggregate functions is changed
+** to TK_AGG_FUNCTION.
+*/
+static int nameResolverStep(void *pArg, Expr *pExpr){
+  NameContext *pNC = (NameContext*)pArg;
+  Parse *pParse;
+
+  if( pExpr==0 ) return 1;
+  assert( pNC!=0 );
+  pParse = pNC->pParse;
+
+  if( ExprHasAnyProperty(pExpr, EP_Resolved) ) return 1;
+  ExprSetProperty(pExpr, EP_Resolved);
+#ifndef NDEBUG
+  if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){
+    SrcList *pSrcList = pNC->pSrcList;
+    int i;
+    for(i=0; i<pNC->pSrcList->nSrc; i++){
+      assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab);
+    }
+  }
+#endif
+  switch( pExpr->op ){
+    /* Double-quoted strings (ex: "abc") are used as identifiers if
+    ** possible.  Otherwise they remain as strings.  Single-quoted
+    ** strings (ex: 'abc') are always string literals.
+    */
+    case TK_STRING: {
+      if( pExpr->token.z[0]=='\'' ) break;
+      /* Fall thru into the TK_ID case if this is a double-quoted string */
+    }
+    /* A lone identifier is the name of a column.
+    */
+    case TK_ID: {
+      lookupName(pParse, 0, 0, &pExpr->token, pNC, pExpr);
+      return 1;
+    }
+  
+    /* A table name and column name:     ID.ID
+    ** Or a database, table and column:  ID.ID.ID
+    */
+    case TK_DOT: {
+      Token *pColumn;
+      Token *pTable;
+      Token *pDb;
+      Expr *pRight;
+
+      /* if( pSrcList==0 ) break; */
+      pRight = pExpr->pRight;
+      if( pRight->op==TK_ID ){
+        pDb = 0;
+        pTable = &pExpr->pLeft->token;
+        pColumn = &pRight->token;
+      }else{
+        assert( pRight->op==TK_DOT );
+        pDb = &pExpr->pLeft->token;
+        pTable = &pRight->pLeft->token;
+        pColumn = &pRight->pRight->token;
+      }
+      lookupName(pParse, pDb, pTable, pColumn, pNC, pExpr);
+      return 1;
+    }
+
+    /* Resolve function names
+    */
+    case TK_CONST_FUNC:
+    case TK_FUNCTION: {
+      ExprList *pList = pExpr->pList;    /* The argument list */
+      int n = pList ? pList->nExpr : 0;  /* Number of arguments */
+      int no_such_func = 0;       /* True if no such function exists */
+      int wrong_num_args = 0;     /* True if wrong number of arguments */
+      int is_agg = 0;             /* True if is an aggregate function */
+      int i;
+      int auth;                   /* Authorization to use the function */
+      int nId;                    /* Number of characters in function name */
+      const char *zId;            /* The function name. */
+      FuncDef *pDef;              /* Information about the function */
+      int enc = ENC(pParse->db);  /* The database encoding */
+
+      zId = (char*)pExpr->token.z;
+      nId = pExpr->token.n;
+      pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
+      if( pDef==0 ){
+        pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0);
+        if( pDef==0 ){
+          no_such_func = 1;
+        }else{
+          wrong_num_args = 1;
+        }
+      }else{
+        is_agg = pDef->xFunc==0;
+      }
+#ifndef SQLITE_OMIT_AUTHORIZATION
+      if( pDef ){
+        auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
+        if( auth!=SQLITE_OK ){
+          if( auth==SQLITE_DENY ){
+            sqlite3ErrorMsg(pParse, "not authorized to use function: %s",
+                                    pDef->zName);
+            pNC->nErr++;
+          }
+          pExpr->op = TK_NULL;
+          return 1;
+        }
+      }
+#endif
+      if( is_agg && !pNC->allowAgg ){
+        sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
+        pNC->nErr++;
+        is_agg = 0;
+      }else if( no_such_func ){
+        sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
+        pNC->nErr++;
+      }else if( wrong_num_args ){
+        sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()",
+             nId, zId);
+        pNC->nErr++;
+      }
+      if( is_agg ){
+        pExpr->op = TK_AGG_FUNCTION;
+        pNC->hasAgg = 1;
+      }
+      if( is_agg ) pNC->allowAgg = 0;
+      for(i=0; pNC->nErr==0 && i<n; i++){
+        walkExprTree(pList->a[i].pExpr, nameResolverStep, pNC);
+      }
+      if( is_agg ) pNC->allowAgg = 1;
+      /* FIX ME:  Compute pExpr->affinity based on the expected return
+      ** type of the function 
+      */
+      return is_agg;
+    }
+#ifndef SQLITE_OMIT_SUBQUERY
+    case TK_SELECT:
+    case TK_EXISTS:
+#endif
+    case TK_IN: {
+      if( pExpr->pSelect ){
+        int nRef = pNC->nRef;
+#ifndef SQLITE_OMIT_CHECK
+        if( pNC->isCheck ){
+          sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints");
+        }
+#endif
+        sqlite3SelectResolve(pParse, pExpr->pSelect, pNC);
+        assert( pNC->nRef>=nRef );
+        if( nRef!=pNC->nRef ){
+          ExprSetProperty(pExpr, EP_VarSelect);
+        }
+      }
+      break;
+    }
+#ifndef SQLITE_OMIT_CHECK
+    case TK_VARIABLE: {
+      if( pNC->isCheck ){
+        sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints");
+      }
+      break;
+    }
+#endif
+  }
+  return 0;
+}
+
+/*
+** This routine walks an expression tree and resolves references to
+** table columns.  Nodes of the form ID.ID or ID resolve into an
+** index to the table in the table list and a column offset.  The 
+** Expr.opcode for such nodes is changed to TK_COLUMN.  The Expr.iTable
+** value is changed to the index of the referenced table in pTabList
+** plus the "base" value.  The base value will ultimately become the
+** VDBE cursor number for a cursor that is pointing into the referenced
+** table.  The Expr.iColumn value is changed to the index of the column 
+** of the referenced table.  The Expr.iColumn value for the special
+** ROWID column is -1.  Any INTEGER PRIMARY KEY column is tried as an
+** alias for ROWID.
+**
+** Also resolve function names and check the functions for proper
+** usage.  Make sure all function names are recognized and all functions
+** have the correct number of arguments.  Leave an error message
+** in pParse->zErrMsg if anything is amiss.  Return the number of errors.
+**
+** If the expression contains aggregate functions then set the EP_Agg
+** property on the expression.
+*/
+int sqlite3ExprResolveNames( 
+  NameContext *pNC,       /* Namespace to resolve expressions in. */
+  Expr *pExpr             /* The expression to be analyzed. */
+){
+  int savedHasAgg;
+
+  if( pExpr==0 ) return 0;
+#if SQLITE_MAX_EXPR_DEPTH>0
+  {
+    if( checkExprHeight(pNC->pParse, pExpr->nHeight + pNC->pParse->nHeight) ){
+      return 1;
+    }
+    pNC->pParse->nHeight += pExpr->nHeight;
+  }
+#endif
+  savedHasAgg = pNC->hasAgg;
+  pNC->hasAgg = 0;
+  walkExprTree(pExpr, nameResolverStep, pNC);
+#if SQLITE_MAX_EXPR_DEPTH>0
+  pNC->pParse->nHeight -= pExpr->nHeight;
+#endif
+  if( pNC->nErr>0 ){
+    ExprSetProperty(pExpr, EP_Error);
+  }
+  if( pNC->hasAgg ){
+    ExprSetProperty(pExpr, EP_Agg);
+  }else if( savedHasAgg ){
+    pNC->hasAgg = 1;
+  }
+  return ExprHasProperty(pExpr, EP_Error);
+}
+
+/*
+** A pointer instance of this structure is used to pass information
+** through walkExprTree into codeSubqueryStep().
+*/
+typedef struct QueryCoder QueryCoder;
+struct QueryCoder {
+  Parse *pParse;       /* The parsing context */
+  NameContext *pNC;    /* Namespace of first enclosing query */
+};
+
+#ifdef SQLITE_TEST
+  int sqlite3_enable_in_opt = 1;
+#else
+  #define sqlite3_enable_in_opt 1
+#endif
+
+/*
+** Return true if the IN operator optimization is enabled and
+** the SELECT statement p exists and is of the
+** simple form:
+**
+**     SELECT <column> FROM <table>
+**
+** If this is the case, it may be possible to use an existing table
+** or index instead of generating an epheremal table.
+*/
+#ifndef SQLITE_OMIT_SUBQUERY
+static int isCandidateForInOpt(Select *p){
+  SrcList *pSrc;
+  ExprList *pEList;
+  Table *pTab;
+  if( !sqlite3_enable_in_opt ) return 0; /* IN optimization must be enabled */
+  if( p==0 ) return 0;                   /* right-hand side of IN is SELECT */
+  if( p->pPrior ) return 0;              /* Not a compound SELECT */
+  if( p->isDistinct ) return 0;          /* No DISTINCT keyword */
+  if( p->isAgg ) return 0;               /* Contains no aggregate functions */
+  if( p->pGroupBy ) return 0;            /* Has no GROUP BY clause */
+  if( p->pLimit ) return 0;              /* Has no LIMIT clause */
+  if( p->pOffset ) return 0;
+  if( p->pWhere ) return 0;              /* Has no WHERE clause */
+  pSrc = p->pSrc;
+  if( pSrc==0 ) return 0;                /* A single table in the FROM clause */
+  if( pSrc->nSrc!=1 ) return 0;
+  if( pSrc->a[0].pSelect ) return 0;     /* FROM clause is not a subquery */
+  pTab = pSrc->a[0].pTab;
+  if( pTab==0 ) return 0;
+  if( pTab->pSelect ) return 0;          /* FROM clause is not a view */
+  if( IsVirtual(pTab) ) return 0;        /* FROM clause not a virtual table */
+  pEList = p->pEList;
+  if( pEList->nExpr!=1 ) return 0;       /* One column in the result set */
+  if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */
+  return 1;
+}
+#endif /* SQLITE_OMIT_SUBQUERY */
+
+/*
+** This function is used by the implementation of the IN (...) operator.
+** It's job is to find or create a b-tree structure that may be used
+** either to test for membership of the (...) set or to iterate through
+** its members, skipping duplicates.
+**
+** The cursor opened on the structure (database table, database index 
+** or ephermal table) is stored in pX->iTable before this function returns.
+** The returned value indicates the structure type, as follows:
+**
+**   IN_INDEX_ROWID - The cursor was opened on a database table.
+**   IN_INDEX_INDEX - The cursor was opened on a database index.
+**   IN_INDEX_EPH -   The cursor was opened on a specially created and
+**                    populated epheremal table.
+**
+** An existing structure may only be used if the SELECT is of the simple
+** form:
+**
+**     SELECT <column> FROM <table>
+**
+** If prNotFound parameter is 0, then the structure will be used to iterate
+** through the set members, skipping any duplicates. In this case an
+** epheremal table must be used unless the selected <column> is guaranteed
+** to be unique - either because it is an INTEGER PRIMARY KEY or it
+** is unique by virtue of a constraint or implicit index.
+**
+** If the prNotFound parameter is not 0, then the structure will be used 
+** for fast set membership tests. In this case an epheremal table must 
+** be used unless <column> is an INTEGER PRIMARY KEY or an index can 
+** be found with <column> as its left-most column.
+**
+** When the structure is being used for set membership tests, the user
+** needs to know whether or not the structure contains an SQL NULL 
+** value in order to correctly evaluate expressions like "X IN (Y, Z)".
+** If there is a chance that the structure may contain a NULL value at
+** runtime, then a register is allocated and the register number written
+** to *prNotFound. If there is no chance that the structure contains a
+** NULL value, then *prNotFound is left unchanged.
+**
+** If a register is allocated and its location stored in *prNotFound, then
+** its initial value is NULL. If the structure does not remain constant
+** for the duration of the query (i.e. the set is a correlated sub-select), 
+** the value of the allocated register is reset to NULL each time the 
+** structure is repopulated. This allows the caller to use vdbe code 
+** equivalent to the following:
+**
+**   if( register==NULL ){
+**     has_null = <test if data structure contains null>
+**     register = 1
+**   }
+**
+** in order to avoid running the <test if data structure contains null>
+** test more often than is necessary.
+*/
+#ifndef SQLITE_OMIT_SUBQUERY
+int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
+  Select *p;
+  int eType = 0;
+  int iTab = pParse->nTab++;
+  int mustBeUnique = !prNotFound;
+
+  /* The follwing if(...) expression is true if the SELECT is of the 
+  ** simple form:
+  **
+  **     SELECT <column> FROM <table>
+  **
+  ** If this is the case, it may be possible to use an existing table
+  ** or index instead of generating an epheremal table.
+  */
+  p = pX->pSelect;
+  if( isCandidateForInOpt(p) ){
+    sqlite3 *db = pParse->db;
+    Index *pIdx;
+    Expr *pExpr = p->pEList->a[0].pExpr;
+    int iCol = pExpr->iColumn;
+    Vdbe *v = sqlite3GetVdbe(pParse);
+
+    /* This function is only called from two places. In both cases the vdbe
+    ** has already been allocated. So assume sqlite3GetVdbe() is always
+    ** successful here.
+    */
+    assert(v);
+    if( iCol<0 ){
+      int iMem = ++pParse->nMem;
+      int iAddr;
+      Table *pTab = p->pSrc->a[0].pTab;
+      int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+      sqlite3VdbeUsesBtree(v, iDb);
+
+      iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
+      sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
+
+      sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
+      eType = IN_INDEX_ROWID;
+
+      sqlite3VdbeJumpHere(v, iAddr);
+    }else{
+      /* The collation sequence used by the comparison. If an index is to 
+      ** be used in place of a temp-table, it must be ordered according
+      ** to this collation sequence.
+      */
+      CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pExpr);
+
+      /* Check that the affinity that will be used to perform the 
+      ** comparison is the same as the affinity of the column. If
+      ** it is not, it is not possible to use any index.
+      */
+      Table *pTab = p->pSrc->a[0].pTab;
+      char aff = comparisonAffinity(pX);
+      int affinity_ok = (pTab->aCol[iCol].affinity==aff||aff==SQLITE_AFF_NONE);
+
+      for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){
+        if( (pIdx->aiColumn[0]==iCol)
+         && (pReq==sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], -1, 0))
+         && (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None))
+        ){
+          int iDb;
+          int iMem = ++pParse->nMem;
+          int iAddr;
+          char *pKey;
+  
+          pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
+          iDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
+          sqlite3VdbeUsesBtree(v, iDb);
+
+          iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
+          sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
+  
+          sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pIdx->nColumn);
+          sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
+                               pKey,P4_KEYINFO_HANDOFF);
+          VdbeComment((v, "%s", pIdx->zName));
+          eType = IN_INDEX_INDEX;
+
+          sqlite3VdbeJumpHere(v, iAddr);
+          if( prNotFound && !pTab->aCol[iCol].notNull ){
+            *prNotFound = ++pParse->nMem;
+          }
+        }
+      }
+    }
+  }
+
+  if( eType==0 ){
+    int rMayHaveNull = 0;
+    if( prNotFound ){
+      *prNotFound = rMayHaveNull = ++pParse->nMem;
+    }
+    sqlite3CodeSubselect(pParse, pX, rMayHaveNull);
+    eType = IN_INDEX_EPH;
+  }else{
+    pX->iTable = iTab;
+  }
+  return eType;
+}
+#endif
+
+/*
+** Generate code for scalar subqueries used as an expression
+** and IN operators.  Examples:
+**
+**     (SELECT a FROM b)          -- subquery
+**     EXISTS (SELECT a FROM b)   -- EXISTS subquery
+**     x IN (4,5,11)              -- IN operator with list on right-hand side
+**     x IN (SELECT a FROM b)     -- IN operator with subquery on the right
+**
+** The pExpr parameter describes the expression that contains the IN
+** operator or subquery.
+*/
+#ifndef SQLITE_OMIT_SUBQUERY
+void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr, int rMayHaveNull){
+  int testAddr = 0;                       /* One-time test address */
+  Vdbe *v = sqlite3GetVdbe(pParse);
+  if( v==0 ) return;
+
+
+  /* This code must be run in its entirety every time it is encountered
+  ** if any of the following is true:
+  **
+  **    *  The right-hand side is a correlated subquery
+  **    *  The right-hand side is an expression list containing variables
+  **    *  We are inside a trigger
+  **
+  ** If all of the above are false, then we can run this code just once
+  ** save the results, and reuse the same result on subsequent invocations.
+  */
+  if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){
+    int mem = ++pParse->nMem;
+    sqlite3VdbeAddOp1(v, OP_If, mem);
+    testAddr = sqlite3VdbeAddOp2(v, OP_Integer, 1, mem);
+    assert( testAddr>0 || pParse->db->mallocFailed );
+  }
+
+  switch( pExpr->op ){
+    case TK_IN: {
+      char affinity;
+      KeyInfo keyInfo;
+      int addr;        /* Address of OP_OpenEphemeral instruction */
+
+      if( rMayHaveNull ){
+        sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull);
+      }
+
+      affinity = sqlite3ExprAffinity(pExpr->pLeft);
+
+      /* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
+      ** expression it is handled the same way. A virtual table is 
+      ** filled with single-field index keys representing the results
+      ** from the SELECT or the <exprlist>.
+      **
+      ** If the 'x' expression is a column value, or the SELECT...
+      ** statement returns a column value, then the affinity of that
+      ** column is used to build the index keys. If both 'x' and the
+      ** SELECT... statement are columns, then numeric affinity is used
+      ** if either column has NUMERIC or INTEGER affinity. If neither
+      ** 'x' nor the SELECT... statement are columns, then numeric affinity
+      ** is used.
+      */
+      pExpr->iTable = pParse->nTab++;
+      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, 1);
+      memset(&keyInfo, 0, sizeof(keyInfo));
+      keyInfo.nField = 1;
+
+      if( pExpr->pSelect ){
+        /* Case 1:     expr IN (SELECT ...)
+        **
+        ** Generate code to write the results of the select into the temporary
+        ** table allocated and opened above.
+        */
+        SelectDest dest;
+        ExprList *pEList;
+
+        sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
+        dest.affinity = (int)affinity;
+        assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
+        if( sqlite3Select(pParse, pExpr->pSelect, &dest, 0, 0, 0) ){
+          return;
+        }
+        pEList = pExpr->pSelect->pEList;
+        if( pEList && pEList->nExpr>0 ){ 
+          keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
+              pEList->a[0].pExpr);
+        }
+      }else if( pExpr->pList ){
+        /* Case 2:     expr IN (exprlist)
+        **
+        ** For each expression, build an index key from the evaluation and
+        ** store it in the temporary table. If <expr> is a column, then use
+        ** that columns affinity when building index keys. If <expr> is not
+        ** a column, use numeric affinity.
+        */
+        int i;
+        ExprList *pList = pExpr->pList;
+        struct ExprList_item *pItem;
+        int r1, r2, r3;
+
+        if( !affinity ){
+          affinity = SQLITE_AFF_NONE;
+        }
+        keyInfo.aColl[0] = pExpr->pLeft->pColl;
+
+        /* Loop through each expression in <exprlist>. */
+        r1 = sqlite3GetTempReg(pParse);
+        r2 = sqlite3GetTempReg(pParse);
+        for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
+          Expr *pE2 = pItem->pExpr;
+
+          /* If the expression is not constant then we will need to
+          ** disable the test that was generated above that makes sure
+          ** this code only executes once.  Because for a non-constant
+          ** expression we need to rerun this code each time.
+          */
+          if( testAddr && !sqlite3ExprIsConstant(pE2) ){
+            sqlite3VdbeChangeToNoop(v, testAddr-1, 2);
+            testAddr = 0;
+          }
+
+          /* Evaluate the expression and insert it into the temp table */
+          pParse->disableColCache++;
+          r3 = sqlite3ExprCodeTarget(pParse, pE2, r1);
+          assert( pParse->disableColCache>0 );
+          pParse->disableColCache--;
+          sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
+          sqlite3ExprCacheAffinityChange(pParse, r3, 1);
+          sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
+        }
+        sqlite3ReleaseTempReg(pParse, r1);
+        sqlite3ReleaseTempReg(pParse, r2);
+      }
+      sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
+      break;
+    }
+
+    case TK_EXISTS:
+    case TK_SELECT: {
+      /* This has to be a scalar SELECT.  Generate code to put the
+      ** value of this select in a memory cell and record the number
+      ** of the memory cell in iColumn.
+      */
+      static const Token one = { (u8*)"1", 0, 1 };
+      Select *pSel;
+      SelectDest dest;
+
+      pSel = pExpr->pSelect;
+      sqlite3SelectDestInit(&dest, 0, ++pParse->nMem);
+      if( pExpr->op==TK_SELECT ){
+        dest.eDest = SRT_Mem;
+        sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iParm);
+        VdbeComment((v, "Init subquery result"));
+      }else{
+        dest.eDest = SRT_Exists;
+        sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iParm);
+        VdbeComment((v, "Init EXISTS result"));
+      }
+      sqlite3ExprDelete(pParse->db, pSel->pLimit);
+      pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one);
+      if( sqlite3Select(pParse, pSel, &dest, 0, 0, 0) ){
+        return;
+      }
+      pExpr->iColumn = dest.iParm;
+      break;
+    }
+  }
+
+  if( testAddr ){
+    sqlite3VdbeJumpHere(v, testAddr-1);
+  }
+
+  return;
+}
+#endif /* SQLITE_OMIT_SUBQUERY */
+
+/*
+** Duplicate an 8-byte value
+*/
+static char *dup8bytes(Vdbe *v, const char *in){
+  char *out = sqlite3DbMallocRaw(sqlite3VdbeDb(v), 8);
+  if( out ){
+    memcpy(out, in, 8);
+  }
+  return out;
+}
+
+/*
+** Generate an instruction that will put the floating point
+** value described by z[0..n-1] into register iMem.
+**
+** The z[] string will probably not be zero-terminated.  But the 
+** z[n] character is guaranteed to be something that does not look
+** like the continuation of the number.
+*/
+static void codeReal(Vdbe *v, const char *z, int n, int negateFlag, int iMem){
+  assert( z || v==0 || sqlite3VdbeDb(v)->mallocFailed );
+  if( z ){
+    double value;
+    char *zV;
+    assert( !isdigit(z[n]) );
+    sqlite3AtoF(z, &value);
+    if( sqlite3IsNaN(value) ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, iMem);
+    }else{
+      if( negateFlag ) value = -value;
+      zV = dup8bytes(v, (char*)&value);
+      sqlite3VdbeAddOp4(v, OP_Real, 0, iMem, 0, zV, P4_REAL);
+    }
+  }
+}
+
+
+/*
+** Generate an instruction that will put the integer describe by
+** text z[0..n-1] into register iMem.
+**
+** The z[] string will probably not be zero-terminated.  But the 
+** z[n] character is guaranteed to be something that does not look
+** like the continuation of the number.
+*/
+static void codeInteger(Vdbe *v, Expr *pExpr, int negFlag, int iMem){
+  const char *z;
+  if( pExpr->flags & EP_IntValue ){
+    int i = pExpr->iTable;
+    if( negFlag ) i = -i;
+    sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
+  }else if( (z = (char*)pExpr->token.z)!=0 ){
+    int i;
+    int n = pExpr->token.n;
+    assert( !isdigit(z[n]) );
+    if( sqlite3GetInt32(z, &i) ){
+      if( negFlag ) i = -i;
+      sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
+    }else if( sqlite3FitsIn64Bits(z, negFlag) ){
+      i64 value;
+      char *zV;
+      sqlite3Atoi64(z, &value);
+      if( negFlag ) value = -value;
+      zV = dup8bytes(v, (char*)&value);
+      sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64);
+    }else{
+      codeReal(v, z, n, negFlag, iMem);
+    }
+  }
+}
+
+
+/*
+** Generate code that will extract the iColumn-th column from
+** table pTab and store the column value in a register.  An effort
+** is made to store the column value in register iReg, but this is
+** not guaranteed.  The location of the column value is returned.
+**
+** There must be an open cursor to pTab in iTable when this routine
+** is called.  If iColumn<0 then code is generated that extracts the rowid.
+**
+** This routine might attempt to reuse the value of the column that
+** has already been loaded into a register.  The value will always
+** be used if it has not undergone any affinity changes.  But if
+** an affinity change has occurred, then the cached value will only be
+** used if allowAffChng is true.
+*/
+int sqlite3ExprCodeGetColumn(
+  Parse *pParse,   /* Parsing and code generating context */
+  Table *pTab,     /* Description of the table we are reading from */
+  int iColumn,     /* Index of the table column */
+  int iTable,      /* The cursor pointing to the table */
+  int iReg,        /* Store results here */
+  int allowAffChng /* True if prior affinity changes are OK */
+){
+  Vdbe *v = pParse->pVdbe;
+  int i;
+  struct yColCache *p;
+
+  for(i=0, p=pParse->aColCache; i<pParse->nColCache; i++, p++){
+    if( p->iTable==iTable && p->iColumn==iColumn
+           && (!p->affChange || allowAffChng) ){
+#if 0
+      sqlite3VdbeAddOp0(v, OP_Noop);
+      VdbeComment((v, "OPT: tab%d.col%d -> r%d", iTable, iColumn, p->iReg));
+#endif
+      return p->iReg;
+    }
+  }  
+  assert( v!=0 );
+  if( iColumn<0 ){
+    int op = (pTab && IsVirtual(pTab)) ? OP_VRowid : OP_Rowid;
+    sqlite3VdbeAddOp2(v, op, iTable, iReg);
+  }else if( pTab==0 ){
+    sqlite3VdbeAddOp3(v, OP_Column, iTable, iColumn, iReg);
+  }else{
+    int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
+    sqlite3VdbeAddOp3(v, op, iTable, iColumn, iReg);
+    sqlite3ColumnDefault(v, pTab, iColumn);
+#ifndef SQLITE_OMIT_FLOATING_POINT
+    if( pTab->aCol[iColumn].affinity==SQLITE_AFF_REAL ){
+      sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
+    }
+#endif
+  }
+  if( pParse->disableColCache==0 ){
+    i = pParse->iColCache;
+    p = &pParse->aColCache[i];
+    p->iTable = iTable;
+    p->iColumn = iColumn;
+    p->iReg = iReg;
+    p->affChange = 0;
+    i++;
+    if( i>=ArraySize(pParse->aColCache) ) i = 0;
+    if( i>pParse->nColCache ) pParse->nColCache = i;
+    pParse->iColCache = i;
+  }
+  return iReg;
+}
+
+/*
+** Clear all column cache entries associated with the vdbe
+** cursor with cursor number iTable.
+*/
+void sqlite3ExprClearColumnCache(Parse *pParse, int iTable){
+  if( iTable<0 ){
+    pParse->nColCache = 0;
+    pParse->iColCache = 0;
+  }else{
+    int i;
+    for(i=0; i<pParse->nColCache; i++){
+      if( pParse->aColCache[i].iTable==iTable ){
+        testcase( i==pParse->nColCache-1 );
+        pParse->aColCache[i] = pParse->aColCache[--pParse->nColCache];
+        pParse->iColCache = pParse->nColCache;
+      }
+    }
+  }
+}
+
+/*
+** Record the fact that an affinity change has occurred on iCount
+** registers starting with iStart.
+*/
+void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, int iCount){
+  int iEnd = iStart + iCount - 1;
+  int i;
+  for(i=0; i<pParse->nColCache; i++){
+    int r = pParse->aColCache[i].iReg;
+    if( r>=iStart && r<=iEnd ){
+      pParse->aColCache[i].affChange = 1;
+    }
+  }
+}
+
+/*
+** Generate code to move content from registers iFrom...iFrom+nReg-1
+** over to iTo..iTo+nReg-1. Keep the column cache up-to-date.
+*/
+void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
+  int i;
+  if( iFrom==iTo ) return;
+  sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
+  for(i=0; i<pParse->nColCache; i++){
+    int x = pParse->aColCache[i].iReg;
+    if( x>=iFrom && x<iFrom+nReg ){
+      pParse->aColCache[i].iReg += iTo-iFrom;
+    }
+  }
+}
+
+/*
+** Generate code to copy content from registers iFrom...iFrom+nReg-1
+** over to iTo..iTo+nReg-1.
+*/
+void sqlite3ExprCodeCopy(Parse *pParse, int iFrom, int iTo, int nReg){
+  int i;
+  if( iFrom==iTo ) return;
+  for(i=0; i<nReg; i++){
+    sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, iFrom+i, iTo+i);
+  }
+}
+
+/*
+** Return true if any register in the range iFrom..iTo (inclusive)
+** is used as part of the column cache.
+*/
+static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
+  int i;
+  for(i=0; i<pParse->nColCache; i++){
+    int r = pParse->aColCache[i].iReg;
+    if( r>=iFrom && r<=iTo ) return 1;
+  }
+  return 0;
+}
+
+/*
+** Theres is a value in register iCurrent.  We ultimately want
+** the value to be in register iTarget.  It might be that
+** iCurrent and iTarget are the same register.
+**
+** We are going to modify the value, so we need to make sure it
+** is not a cached register.  If iCurrent is a cached register,
+** then try to move the value over to iTarget.  If iTarget is a
+** cached register, then clear the corresponding cache line.
+**
+** Return the register that the value ends up in.
+*/
+int sqlite3ExprWritableRegister(Parse *pParse, int iCurrent, int iTarget){
+  int i;
+  assert( pParse->pVdbe!=0 );
+  if( !usedAsColumnCache(pParse, iCurrent, iCurrent) ){
+    return iCurrent;
+  }
+  if( iCurrent!=iTarget ){
+    sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, iCurrent, iTarget);
+  }
+  for(i=0; i<pParse->nColCache; i++){
+    if( pParse->aColCache[i].iReg==iTarget ){
+      pParse->aColCache[i] = pParse->aColCache[--pParse->nColCache];
+      pParse->iColCache = pParse->nColCache;
+    }
+  }
+  return iTarget;
+}
+
+/*
+** If the last instruction coded is an ephemeral copy of any of
+** the registers in the nReg registers beginning with iReg, then
+** convert the last instruction from OP_SCopy to OP_Copy.
+*/
+void sqlite3ExprHardCopy(Parse *pParse, int iReg, int nReg){
+  int addr;
+  VdbeOp *pOp;
+  Vdbe *v;
+
+  v = pParse->pVdbe;
+  addr = sqlite3VdbeCurrentAddr(v);
+  pOp = sqlite3VdbeGetOp(v, addr-1);
+  assert( pOp || pParse->db->mallocFailed );
+  if( pOp && pOp->opcode==OP_SCopy && pOp->p1>=iReg && pOp->p1<iReg+nReg ){
+    pOp->opcode = OP_Copy;
+  }
+}
+
+/*
+** Generate code into the current Vdbe to evaluate the given
+** expression.  Attempt to store the results in register "target".
+** Return the register where results are stored.
+**
+** With this routine, there is no guaranteed that results will
+** be stored in target.  The result might be stored in some other
+** register if it is convenient to do so.  The calling function
+** must check the return code and move the results to the desired
+** register.
+*/
+int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
+  Vdbe *v = pParse->pVdbe;  /* The VM under construction */
+  int op;                   /* The opcode being coded */
+  int inReg = target;       /* Results stored in register inReg */
+  int regFree1 = 0;         /* If non-zero free this temporary register */
+  int regFree2 = 0;         /* If non-zero free this temporary register */
+  int r1, r2, r3, r4;       /* Various register numbers */
+
+  assert( v!=0 || pParse->db->mallocFailed );
+  assert( target>0 && target<=pParse->nMem );
+  if( v==0 ) return 0;
+
+  if( pExpr==0 ){
+    op = TK_NULL;
+  }else{
+    op = pExpr->op;
+  }
+  switch( op ){
+    case TK_AGG_COLUMN: {
+      AggInfo *pAggInfo = pExpr->pAggInfo;
+      struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
+      if( !pAggInfo->directMode ){
+        assert( pCol->iMem>0 );
+        inReg = pCol->iMem;
+        break;
+      }else if( pAggInfo->useSortingIdx ){
+        sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdx,
+                              pCol->iSorterColumn, target);
+        break;
+      }
+      /* Otherwise, fall thru into the TK_COLUMN case */
+    }
+    case TK_COLUMN: {
+      if( pExpr->iTable<0 ){
+        /* This only happens when coding check constraints */
+        assert( pParse->ckBase>0 );
+        inReg = pExpr->iColumn + pParse->ckBase;
+      }else{
+        testcase( (pExpr->flags & EP_AnyAff)!=0 );
+        inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
+                                 pExpr->iColumn, pExpr->iTable, target,
+                                 pExpr->flags & EP_AnyAff);
+      }
+      break;
+    }
+    case TK_INTEGER: {
+      codeInteger(v, pExpr, 0, target);
+      break;
+    }
+    case TK_FLOAT: {
+      codeReal(v, (char*)pExpr->token.z, pExpr->token.n, 0, target);
+      break;
+    }
+    case TK_STRING: {
+      sqlite3DequoteExpr(pParse->db, pExpr);
+      sqlite3VdbeAddOp4(v,OP_String8, 0, target, 0,
+                        (char*)pExpr->token.z, pExpr->token.n);
+      break;
+    }
+    case TK_NULL: {
+      sqlite3VdbeAddOp2(v, OP_Null, 0, target);
+      break;
+    }
+#ifndef SQLITE_OMIT_BLOB_LITERAL
+    case TK_BLOB: {
+      int n;
+      const char *z;
+      char *zBlob;
+      assert( pExpr->token.n>=3 );
+      assert( pExpr->token.z[0]=='x' || pExpr->token.z[0]=='X' );
+      assert( pExpr->token.z[1]=='\'' );
+      assert( pExpr->token.z[pExpr->token.n-1]=='\'' );
+      n = pExpr->token.n - 3;
+      z = (char*)pExpr->token.z + 2;
+      zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
+      sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
+      break;
+    }
+#endif
+    case TK_VARIABLE: {
+      sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iTable, target);
+      if( pExpr->token.n>1 ){
+        sqlite3VdbeChangeP4(v, -1, (char*)pExpr->token.z, pExpr->token.n);
+      }
+      break;
+    }
+    case TK_REGISTER: {
+      inReg = pExpr->iTable;
+      break;
+    }
+#ifndef SQLITE_OMIT_CAST
+    case TK_CAST: {
+      /* Expressions of the form:   CAST(pLeft AS token) */
+      int aff, to_op;
+      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
+      aff = sqlite3AffinityType(&pExpr->token);
+      to_op = aff - SQLITE_AFF_TEXT + OP_ToText;
+      assert( to_op==OP_ToText    || aff!=SQLITE_AFF_TEXT    );
+      assert( to_op==OP_ToBlob    || aff!=SQLITE_AFF_NONE    );
+      assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC );
+      assert( to_op==OP_ToInt     || aff!=SQLITE_AFF_INTEGER );
+      assert( to_op==OP_ToReal    || aff!=SQLITE_AFF_REAL    );
+      testcase( to_op==OP_ToText );
+      testcase( to_op==OP_ToBlob );
+      testcase( to_op==OP_ToNumeric );
+      testcase( to_op==OP_ToInt );
+      testcase( to_op==OP_ToReal );
+      sqlite3VdbeAddOp1(v, to_op, inReg);
+      testcase( usedAsColumnCache(pParse, inReg, inReg) );
+      sqlite3ExprCacheAffinityChange(pParse, inReg, 1);
+      break;
+    }
+#endif /* SQLITE_OMIT_CAST */
+    case TK_LT:
+    case TK_LE:
+    case TK_GT:
+    case TK_GE:
+    case TK_NE:
+    case TK_EQ: {
+      assert( TK_LT==OP_Lt );
+      assert( TK_LE==OP_Le );
+      assert( TK_GT==OP_Gt );
+      assert( TK_GE==OP_Ge );
+      assert( TK_EQ==OP_Eq );
+      assert( TK_NE==OP_Ne );
+      testcase( op==TK_LT );
+      testcase( op==TK_LE );
+      testcase( op==TK_GT );
+      testcase( op==TK_GE );
+      testcase( op==TK_EQ );
+      testcase( op==TK_NE );
+      codeCompareOperands(pParse, pExpr->pLeft, &r1, &regFree1,
+                                  pExpr->pRight, &r2, &regFree2);
+      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
+                  r1, r2, inReg, SQLITE_STOREP2);
+      testcase( regFree1==0 );
+      testcase( regFree2==0 );
+      break;
+    }
+    case TK_AND:
+    case TK_OR:
+    case TK_PLUS:
+    case TK_STAR:
+    case TK_MINUS:
+    case TK_REM:
+    case TK_BITAND:
+    case TK_BITOR:
+    case TK_SLASH:
+    case TK_LSHIFT:
+    case TK_RSHIFT: 
+    case TK_CONCAT: {
+      assert( TK_AND==OP_And );
+      assert( TK_OR==OP_Or );
+      assert( TK_PLUS==OP_Add );
+      assert( TK_MINUS==OP_Subtract );
+      assert( TK_REM==OP_Remainder );
+      assert( TK_BITAND==OP_BitAnd );
+      assert( TK_BITOR==OP_BitOr );
+      assert( TK_SLASH==OP_Divide );
+      assert( TK_LSHIFT==OP_ShiftLeft );
+      assert( TK_RSHIFT==OP_ShiftRight );
+      assert( TK_CONCAT==OP_Concat );
+      testcase( op==TK_AND );
+      testcase( op==TK_OR );
+      testcase( op==TK_PLUS );
+      testcase( op==TK_MINUS );
+      testcase( op==TK_REM );
+      testcase( op==TK_BITAND );
+      testcase( op==TK_BITOR );
+      testcase( op==TK_SLASH );
+      testcase( op==TK_LSHIFT );
+      testcase( op==TK_RSHIFT );
+      testcase( op==TK_CONCAT );
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
+      sqlite3VdbeAddOp3(v, op, r2, r1, target);
+      testcase( regFree1==0 );
+      testcase( regFree2==0 );
+      break;
+    }
+    case TK_UMINUS: {
+      Expr *pLeft = pExpr->pLeft;
+      assert( pLeft );
+      if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){
+        if( pLeft->op==TK_FLOAT ){
+          codeReal(v, (char*)pLeft->token.z, pLeft->token.n, 1, target);
+        }else{
+          codeInteger(v, pLeft, 1, target);
+        }
+      }else{
+        regFree1 = r1 = sqlite3GetTempReg(pParse);
+        sqlite3VdbeAddOp2(v, OP_Integer, 0, r1);
+        r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree2);
+        sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
+        testcase( regFree2==0 );
+      }
+      inReg = target;
+      break;
+    }
+    case TK_BITNOT:
+    case TK_NOT: {
+      assert( TK_BITNOT==OP_BitNot );
+      assert( TK_NOT==OP_Not );
+      testcase( op==TK_BITNOT );
+      testcase( op==TK_NOT );
+      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
+      testcase( inReg==target );
+      testcase( usedAsColumnCache(pParse, inReg, inReg) );
+      inReg = sqlite3ExprWritableRegister(pParse, inReg, target);
+      sqlite3VdbeAddOp1(v, op, inReg);
+      break;
+    }
+    case TK_ISNULL:
+    case TK_NOTNULL: {
+      int addr;
+      assert( TK_ISNULL==OP_IsNull );
+      assert( TK_NOTNULL==OP_NotNull );
+      testcase( op==TK_ISNULL );
+      testcase( op==TK_NOTNULL );
+      sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      testcase( regFree1==0 );
+      addr = sqlite3VdbeAddOp1(v, op, r1);
+      sqlite3VdbeAddOp2(v, OP_AddImm, target, -1);
+      sqlite3VdbeJumpHere(v, addr);
+      break;
+    }
+    case TK_AGG_FUNCTION: {
+      AggInfo *pInfo = pExpr->pAggInfo;
+      if( pInfo==0 ){
+        sqlite3ErrorMsg(pParse, "misuse of aggregate: %T",
+            &pExpr->span);
+      }else{
+        inReg = pInfo->aFunc[pExpr->iAgg].iMem;
+      }
+      break;
+    }
+    case TK_CONST_FUNC:
+    case TK_FUNCTION: {
+      ExprList *pList = pExpr->pList;
+      int nExpr = pList ? pList->nExpr : 0;
+      FuncDef *pDef;
+      int nId;
+      const char *zId;
+      int constMask = 0;
+      int i;
+      sqlite3 *db = pParse->db;
+      u8 enc = ENC(db);
+      CollSeq *pColl = 0;
+
+      testcase( op==TK_CONST_FUNC );
+      testcase( op==TK_FUNCTION );
+      zId = (char*)pExpr->token.z;
+      nId = pExpr->token.n;
+      pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, enc, 0);
+      assert( pDef!=0 );
+      if( pList ){
+        nExpr = pList->nExpr;
+        r1 = sqlite3GetTempRange(pParse, nExpr);
+        sqlite3ExprCodeExprList(pParse, pList, r1, 1);
+      }else{
+        nExpr = r1 = 0;
+      }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+      /* Possibly overload the function if the first argument is
+      ** a virtual table column.
+      **
+      ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
+      ** second argument, not the first, as the argument to test to
+      ** see if it is a column in a virtual table.  This is done because
+      ** the left operand of infix functions (the operand we want to
+      ** control overloading) ends up as the second argument to the
+      ** function.  The expression "A glob B" is equivalent to 
+      ** "glob(B,A).  We want to use the A in "A glob B" to test
+      ** for function overloading.  But we use the B term in "glob(B,A)".
+      */
+      if( nExpr>=2 && (pExpr->flags & EP_InfixFunc) ){
+        pDef = sqlite3VtabOverloadFunction(db, pDef, nExpr, pList->a[1].pExpr);
+      }else if( nExpr>0 ){
+        pDef = sqlite3VtabOverloadFunction(db, pDef, nExpr, pList->a[0].pExpr);
+      }
+#endif
+      for(i=0; i<nExpr && i<32; i++){
+        if( sqlite3ExprIsConstant(pList->a[i].pExpr) ){
+          constMask |= (1<<i);
+        }
+        if( pDef->needCollSeq && !pColl ){
+          pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
+        }
+      }
+      if( pDef->needCollSeq ){
+        if( !pColl ) pColl = pParse->db->pDfltColl; 
+        sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
+      }
+      sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
+                        (char*)pDef, P4_FUNCDEF);
+      sqlite3VdbeChangeP5(v, nExpr);
+      if( nExpr ){
+        sqlite3ReleaseTempRange(pParse, r1, nExpr);
+      }
+      sqlite3ExprCacheAffinityChange(pParse, r1, nExpr);
+      break;
+    }
+#ifndef SQLITE_OMIT_SUBQUERY
+    case TK_EXISTS:
+    case TK_SELECT: {
+      testcase( op==TK_EXISTS );
+      testcase( op==TK_SELECT );
+      if( pExpr->iColumn==0 ){
+        sqlite3CodeSubselect(pParse, pExpr, 0);
+      }
+      inReg = pExpr->iColumn;
+      break;
+    }
+    case TK_IN: {
+      int rNotFound = 0;
+      int rMayHaveNull = 0;
+      int j2, j3, j4, j5;
+      char affinity;
+      int eType;
+
+      VdbeNoopComment((v, "begin IN expr r%d", target));
+      eType = sqlite3FindInIndex(pParse, pExpr, &rMayHaveNull);
+      if( rMayHaveNull ){
+        rNotFound = ++pParse->nMem;
+      }
+
+      /* Figure out the affinity to use to create a key from the results
+      ** of the expression. affinityStr stores a static string suitable for
+      ** P4 of OP_MakeRecord.
+      */
+      affinity = comparisonAffinity(pExpr);
+
+
+      /* Code the <expr> from "<expr> IN (...)". The temporary table
+      ** pExpr->iTable contains the values that make up the (...) set.
+      */
+      pParse->disableColCache++;
+      sqlite3ExprCode(pParse, pExpr->pLeft, target);
+      pParse->disableColCache--;
+      j2 = sqlite3VdbeAddOp1(v, OP_IsNull, target);
+      if( eType==IN_INDEX_ROWID ){
+        j3 = sqlite3VdbeAddOp1(v, OP_MustBeInt, target);
+        j4 = sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, 0, target);
+        sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
+        j5 = sqlite3VdbeAddOp0(v, OP_Goto);
+        sqlite3VdbeJumpHere(v, j3);
+        sqlite3VdbeJumpHere(v, j4);
+        sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
+      }else{
+        r2 = regFree2 = sqlite3GetTempReg(pParse);
+
+        /* Create a record and test for set membership. If the set contains
+        ** the value, then jump to the end of the test code. The target
+        ** register still contains the true (1) value written to it earlier.
+        */
+        sqlite3VdbeAddOp4(v, OP_MakeRecord, target, 1, r2, &affinity, 1);
+        sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
+        j5 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, r2);
+
+        /* If the set membership test fails, then the result of the 
+        ** "x IN (...)" expression must be either 0 or NULL. If the set
+        ** contains no NULL values, then the result is 0. If the set 
+        ** contains one or more NULL values, then the result of the
+        ** expression is also NULL.
+        */
+        if( rNotFound==0 ){
+          /* This branch runs if it is known at compile time (now) that 
+          ** the set contains no NULL values. This happens as the result
+          ** of a "NOT NULL" constraint in the database schema. No need
+          ** to test the data structure at runtime in this case.
+          */
+          sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
+        }else{
+          /* This block populates the rNotFound register with either NULL
+          ** or 0 (an integer value). If the data structure contains one
+          ** or more NULLs, then set rNotFound to NULL. Otherwise, set it
+          ** to 0. If register rMayHaveNull is already set to some value
+          ** other than NULL, then the test has already been run and 
+          ** rNotFound is already populated.
+          */
+          static const char nullRecord[] = { 0x02, 0x00 };
+          j3 = sqlite3VdbeAddOp1(v, OP_NotNull, rMayHaveNull);
+          sqlite3VdbeAddOp2(v, OP_Null, 0, rNotFound);
+          sqlite3VdbeAddOp4(v, OP_Blob, 2, rMayHaveNull, 0, 
+                             nullRecord, P4_STATIC);
+          j4 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, rMayHaveNull);
+          sqlite3VdbeAddOp2(v, OP_Integer, 0, rNotFound);
+          sqlite3VdbeJumpHere(v, j4);
+          sqlite3VdbeJumpHere(v, j3);
+
+          /* Copy the value of register rNotFound (which is either NULL or 0)
+	  ** into the target register. This will be the result of the
+          ** expression.
+          */
+          sqlite3VdbeAddOp2(v, OP_Copy, rNotFound, target);
+        }
+      }
+      sqlite3VdbeJumpHere(v, j2);
+      sqlite3VdbeJumpHere(v, j5);
+      VdbeComment((v, "end IN expr r%d", target));
+      break;
+    }
+#endif
+    /*
+    **    x BETWEEN y AND z
+    **
+    ** This is equivalent to
+    **
+    **    x>=y AND x<=z
+    **
+    ** X is stored in pExpr->pLeft.
+    ** Y is stored in pExpr->pList->a[0].pExpr.
+    ** Z is stored in pExpr->pList->a[1].pExpr.
+    */
+    case TK_BETWEEN: {
+      Expr *pLeft = pExpr->pLeft;
+      struct ExprList_item *pLItem = pExpr->pList->a;
+      Expr *pRight = pLItem->pExpr;
+
+      codeCompareOperands(pParse, pLeft, &r1, &regFree1,
+                                  pRight, &r2, &regFree2);
+      testcase( regFree1==0 );
+      testcase( regFree2==0 );
+      r3 = sqlite3GetTempReg(pParse);
+      r4 = sqlite3GetTempReg(pParse);
+      codeCompare(pParse, pLeft, pRight, OP_Ge,
+                  r1, r2, r3, SQLITE_STOREP2);
+      pLItem++;
+      pRight = pLItem->pExpr;
+      sqlite3ReleaseTempReg(pParse, regFree2);
+      r2 = sqlite3ExprCodeTemp(pParse, pRight, &regFree2);
+      testcase( regFree2==0 );
+      codeCompare(pParse, pLeft, pRight, OP_Le, r1, r2, r4, SQLITE_STOREP2);
+      sqlite3VdbeAddOp3(v, OP_And, r3, r4, target);
+      sqlite3ReleaseTempReg(pParse, r3);
+      sqlite3ReleaseTempReg(pParse, r4);
+      break;
+    }
+    case TK_UPLUS: {
+      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
+      break;
+    }
+
+    /*
+    ** Form A:
+    **   CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
+    **
+    ** Form B:
+    **   CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
+    **
+    ** Form A is can be transformed into the equivalent form B as follows:
+    **   CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
+    **        WHEN x=eN THEN rN ELSE y END
+    **
+    ** X (if it exists) is in pExpr->pLeft.
+    ** Y is in pExpr->pRight.  The Y is also optional.  If there is no
+    ** ELSE clause and no other term matches, then the result of the
+    ** exprssion is NULL.
+    ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
+    **
+    ** The result of the expression is the Ri for the first matching Ei,
+    ** or if there is no matching Ei, the ELSE term Y, or if there is
+    ** no ELSE term, NULL.
+    */
+    case TK_CASE: {
+      int endLabel;                     /* GOTO label for end of CASE stmt */
+      int nextCase;                     /* GOTO label for next WHEN clause */
+      int nExpr;                        /* 2x number of WHEN terms */
+      int i;                            /* Loop counter */
+      ExprList *pEList;                 /* List of WHEN terms */
+      struct ExprList_item *aListelem;  /* Array of WHEN terms */
+      Expr opCompare;                   /* The X==Ei expression */
+      Expr cacheX;                      /* Cached expression X */
+      Expr *pX;                         /* The X expression */
+      Expr *pTest;                      /* X==Ei (form A) or just Ei (form B) */
+
+      assert(pExpr->pList);
+      assert((pExpr->pList->nExpr % 2) == 0);
+      assert(pExpr->pList->nExpr > 0);
+      pEList = pExpr->pList;
+      aListelem = pEList->a;
+      nExpr = pEList->nExpr;
+      endLabel = sqlite3VdbeMakeLabel(v);
+      if( (pX = pExpr->pLeft)!=0 ){
+        cacheX = *pX;
+        testcase( pX->op==TK_COLUMN || pX->op==TK_REGISTER );
+        cacheX.iTable = sqlite3ExprCodeTemp(pParse, pX, &regFree1);
+        testcase( regFree1==0 );
+        cacheX.op = TK_REGISTER;
+        cacheX.iColumn = 0;
+        opCompare.op = TK_EQ;
+        opCompare.pLeft = &cacheX;
+        pTest = &opCompare;
+      }
+      pParse->disableColCache++;
+      for(i=0; i<nExpr; i=i+2){
+        if( pX ){
+          opCompare.pRight = aListelem[i].pExpr;
+        }else{
+          pTest = aListelem[i].pExpr;
+        }
+        nextCase = sqlite3VdbeMakeLabel(v);
+        testcase( pTest->op==TK_COLUMN || pTest->op==TK_REGISTER );
+        sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
+        testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
+        testcase( aListelem[i+1].pExpr->op==TK_REGISTER );
+        sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
+        sqlite3VdbeAddOp2(v, OP_Goto, 0, endLabel);
+        sqlite3VdbeResolveLabel(v, nextCase);
+      }
+      if( pExpr->pRight ){
+        sqlite3ExprCode(pParse, pExpr->pRight, target);
+      }else{
+        sqlite3VdbeAddOp2(v, OP_Null, 0, target);
+      }
+      sqlite3VdbeResolveLabel(v, endLabel);
+      assert( pParse->disableColCache>0 );
+      pParse->disableColCache--;
+      break;
+    }
+#ifndef SQLITE_OMIT_TRIGGER
+    case TK_RAISE: {
+      if( !pParse->trigStack ){
+        sqlite3ErrorMsg(pParse,
+                       "RAISE() may only be used within a trigger-program");
+        return 0;
+      }
+      if( pExpr->iColumn!=OE_Ignore ){
+         assert( pExpr->iColumn==OE_Rollback ||
+                 pExpr->iColumn == OE_Abort ||
+                 pExpr->iColumn == OE_Fail );
+         sqlite3DequoteExpr(pParse->db, pExpr);
+         sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn, 0,
+                        (char*)pExpr->token.z, pExpr->token.n);
+      } else {
+         assert( pExpr->iColumn == OE_Ignore );
+         sqlite3VdbeAddOp2(v, OP_ContextPop, 0, 0);
+         sqlite3VdbeAddOp2(v, OP_Goto, 0, pParse->trigStack->ignoreJump);
+         VdbeComment((v, "raise(IGNORE)"));
+      }
+      break;
+    }
+#endif
+  }
+  sqlite3ReleaseTempReg(pParse, regFree1);
+  sqlite3ReleaseTempReg(pParse, regFree2);
+  return inReg;
+}
+
+/*
+** Generate code to evaluate an expression and store the results
+** into a register.  Return the register number where the results
+** are stored.
+**
+** If the register is a temporary register that can be deallocated,
+** then write its number into *pReg.  If the result register is not
+** a temporary, then set *pReg to zero.
+*/
+int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
+  int r1 = sqlite3GetTempReg(pParse);
+  int r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
+  if( r2==r1 ){
+    *pReg = r1;
+  }else{
+    sqlite3ReleaseTempReg(pParse, r1);
+    *pReg = 0;
+  }
+  return r2;
+}
+
+/*
+** Generate code that will evaluate expression pExpr and store the
+** results in register target.  The results are guaranteed to appear
+** in register target.
+*/
+int sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
+  int inReg;
+
+  assert( target>0 && target<=pParse->nMem );
+  inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
+  assert( pParse->pVdbe || pParse->db->mallocFailed );
+  if( inReg!=target && pParse->pVdbe ){
+    sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target);
+  }
+  return target;
+}
+
+/*
+** Generate code that evalutes the given expression and puts the result
+** in register target.
+**
+** Also make a copy of the expression results into another "cache" register
+** and modify the expression so that the next time it is evaluated,
+** the result is a copy of the cache register.
+**
+** This routine is used for expressions that are used multiple 
+** times.  They are evaluated once and the results of the expression
+** are reused.
+*/
+int sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){
+  Vdbe *v = pParse->pVdbe;
+  int inReg;
+  inReg = sqlite3ExprCode(pParse, pExpr, target);
+  assert( target>0 );
+  if( pExpr->op!=TK_REGISTER ){  
+    int iMem;
+    iMem = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Copy, inReg, iMem);
+    pExpr->iTable = iMem;
+    pExpr->iColumn = pExpr->op;
+    pExpr->op = TK_REGISTER;
+  }
+  return inReg;
+}
+
+/*
+** Return TRUE if pExpr is an constant expression that is appropriate
+** for factoring out of a loop.  Appropriate expressions are:
+**
+**    *  Any expression that evaluates to two or more opcodes.
+**
+**    *  Any OP_Integer, OP_Real, OP_String, OP_Blob, OP_Null, 
+**       or OP_Variable that does not need to be placed in a 
+**       specific register.
+**
+** There is no point in factoring out single-instruction constant
+** expressions that need to be placed in a particular register.  
+** We could factor them out, but then we would end up adding an
+** OP_SCopy instruction to move the value into the correct register
+** later.  We might as well just use the original instruction and
+** avoid the OP_SCopy.
+*/
+static int isAppropriateForFactoring(Expr *p){
+  if( !sqlite3ExprIsConstantNotJoin(p) ){
+    return 0;  /* Only constant expressions are appropriate for factoring */
+  }
+  if( (p->flags & EP_FixedDest)==0 ){
+    return 1;  /* Any constant without a fixed destination is appropriate */
+  }
+  while( p->op==TK_UPLUS ) p = p->pLeft;
+  switch( p->op ){
+#ifndef SQLITE_OMIT_BLOB_LITERAL
+    case TK_BLOB:
+#endif
+    case TK_VARIABLE:
+    case TK_INTEGER:
+    case TK_FLOAT:
+    case TK_NULL:
+    case TK_STRING: {
+      testcase( p->op==TK_BLOB );
+      testcase( p->op==TK_VARIABLE );
+      testcase( p->op==TK_INTEGER );
+      testcase( p->op==TK_FLOAT );
+      testcase( p->op==TK_NULL );
+      testcase( p->op==TK_STRING );
+      /* Single-instruction constants with a fixed destination are
+      ** better done in-line.  If we factor them, they will just end
+      ** up generating an OP_SCopy to move the value to the destination
+      ** register. */
+      return 0;
+    }
+    case TK_UMINUS: {
+       if( p->pLeft->op==TK_FLOAT || p->pLeft->op==TK_INTEGER ){
+         return 0;
+       }
+       break;
+    }
+    default: {
+      break;
+    }
+  }
+  return 1;
+}
+
+/*
+** If pExpr is a constant expression that is appropriate for
+** factoring out of a loop, then evaluate the expression
+** into a register and convert the expression into a TK_REGISTER
+** expression.
+*/
+static int evalConstExpr(void *pArg, Expr *pExpr){
+  Parse *pParse = (Parse*)pArg;
+  switch( pExpr->op ){
+    case TK_REGISTER: {
+      return 1;
+    }
+    case TK_FUNCTION:
+    case TK_AGG_FUNCTION:
+    case TK_CONST_FUNC: {
+      /* The arguments to a function have a fixed destination.
+      ** Mark them this way to avoid generated unneeded OP_SCopy
+      ** instructions. 
+      */
+      ExprList *pList = pExpr->pList;
+      if( pList ){
+        int i = pList->nExpr;
+        struct ExprList_item *pItem = pList->a;
+        for(; i>0; i--, pItem++){
+          if( pItem->pExpr ) pItem->pExpr->flags |= EP_FixedDest;
+        }
+      }
+      break;
+    }
+  }
+  if( isAppropriateForFactoring(pExpr) ){
+    int r1 = ++pParse->nMem;
+    int r2;
+    r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
+    if( r1!=r2 ) sqlite3ReleaseTempReg(pParse, r1);
+    pExpr->iColumn = pExpr->op;
+    pExpr->op = TK_REGISTER;
+    pExpr->iTable = r2;
+    return 1;
+  }
+  return 0;
+}
+
+/*
+** Preevaluate constant subexpressions within pExpr and store the
+** results in registers.  Modify pExpr so that the constant subexpresions
+** are TK_REGISTER opcodes that refer to the precomputed values.
+*/
+void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){
+   walkExprTree(pExpr, evalConstExpr, pParse);
+}
+
+
+/*
+** Generate code that pushes the value of every element of the given
+** expression list into a sequence of registers beginning at target.
+**
+** Return the number of elements evaluated.
+*/
+int sqlite3ExprCodeExprList(
+  Parse *pParse,     /* Parsing context */
+  ExprList *pList,   /* The expression list to be coded */
+  int target,        /* Where to write results */
+  int doHardCopy     /* Call sqlite3ExprHardCopy on each element if true */
+){
+  struct ExprList_item *pItem;
+  int i, n;
+  assert( pList!=0 || pParse->db->mallocFailed );
+  if( pList==0 ){
+    return 0;
+  }
+  assert( target>0 );
+  n = pList->nExpr;
+  for(pItem=pList->a, i=0; i<n; i++, pItem++){
+    sqlite3ExprCode(pParse, pItem->pExpr, target+i);
+    if( doHardCopy ) sqlite3ExprHardCopy(pParse, target, n);
+  }
+  return n;
+}
+
+/*
+** Generate code for a boolean expression such that a jump is made
+** to the label "dest" if the expression is true but execution
+** continues straight thru if the expression is false.
+**
+** If the expression evaluates to NULL (neither true nor false), then
+** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
+**
+** This code depends on the fact that certain token values (ex: TK_EQ)
+** are the same as opcode values (ex: OP_Eq) that implement the corresponding
+** operation.  Special comments in vdbe.c and the mkopcodeh.awk script in
+** the make process cause these values to align.  Assert()s in the code
+** below verify that the numbers are aligned correctly.
+*/
+void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
+  Vdbe *v = pParse->pVdbe;
+  int op = 0;
+  int regFree1 = 0;
+  int regFree2 = 0;
+  int r1, r2;
+
+  assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
+  if( v==0 || pExpr==0 ) return;
+  op = pExpr->op;
+  switch( op ){
+    case TK_AND: {
+      int d2 = sqlite3VdbeMakeLabel(v);
+      testcase( jumpIfNull==0 );
+      testcase( pParse->disableColCache==0 );
+      sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL);
+      pParse->disableColCache++;
+      sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
+      assert( pParse->disableColCache>0 );
+      pParse->disableColCache--;
+      sqlite3VdbeResolveLabel(v, d2);
+      break;
+    }
+    case TK_OR: {
+      testcase( jumpIfNull==0 );
+      testcase( pParse->disableColCache==0 );
+      sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
+      pParse->disableColCache++;
+      sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
+      assert( pParse->disableColCache>0 );
+      pParse->disableColCache--;
+      break;
+    }
+    case TK_NOT: {
+      testcase( jumpIfNull==0 );
+      sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
+      break;
+    }
+    case TK_LT:
+    case TK_LE:
+    case TK_GT:
+    case TK_GE:
+    case TK_NE:
+    case TK_EQ: {
+      assert( TK_LT==OP_Lt );
+      assert( TK_LE==OP_Le );
+      assert( TK_GT==OP_Gt );
+      assert( TK_GE==OP_Ge );
+      assert( TK_EQ==OP_Eq );
+      assert( TK_NE==OP_Ne );
+      testcase( op==TK_LT );
+      testcase( op==TK_LE );
+      testcase( op==TK_GT );
+      testcase( op==TK_GE );
+      testcase( op==TK_EQ );
+      testcase( op==TK_NE );
+      testcase( jumpIfNull==0 );
+      codeCompareOperands(pParse, pExpr->pLeft, &r1, &regFree1,
+                                  pExpr->pRight, &r2, &regFree2);
+      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
+                  r1, r2, dest, jumpIfNull);
+      testcase( regFree1==0 );
+      testcase( regFree2==0 );
+      break;
+    }
+    case TK_ISNULL:
+    case TK_NOTNULL: {
+      assert( TK_ISNULL==OP_IsNull );
+      assert( TK_NOTNULL==OP_NotNull );
+      testcase( op==TK_ISNULL );
+      testcase( op==TK_NOTNULL );
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      sqlite3VdbeAddOp2(v, op, r1, dest);
+      testcase( regFree1==0 );
+      break;
+    }
+    case TK_BETWEEN: {
+      /*    x BETWEEN y AND z
+      **
+      ** Is equivalent to 
+      **
+      **    x>=y AND x<=z
+      **
+      ** Code it as such, taking care to do the common subexpression
+      ** elementation of x.
+      */
+      Expr exprAnd;
+      Expr compLeft;
+      Expr compRight;
+      Expr exprX;
+
+      exprX = *pExpr->pLeft;
+      exprAnd.op = TK_AND;
+      exprAnd.pLeft = &compLeft;
+      exprAnd.pRight = &compRight;
+      compLeft.op = TK_GE;
+      compLeft.pLeft = &exprX;
+      compLeft.pRight = pExpr->pList->a[0].pExpr;
+      compRight.op = TK_LE;
+      compRight.pLeft = &exprX;
+      compRight.pRight = pExpr->pList->a[1].pExpr;
+      exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, &regFree1);
+      testcase( regFree1==0 );
+      exprX.op = TK_REGISTER;
+      testcase( jumpIfNull==0 );
+      sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
+      break;
+    }
+    default: {
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
+      sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
+      testcase( regFree1==0 );
+      testcase( jumpIfNull==0 );
+      break;
+    }
+  }
+  sqlite3ReleaseTempReg(pParse, regFree1);
+  sqlite3ReleaseTempReg(pParse, regFree2);  
+}
+
+/*
+** Generate code for a boolean expression such that a jump is made
+** to the label "dest" if the expression is false but execution
+** continues straight thru if the expression is true.
+**
+** If the expression evaluates to NULL (neither true nor false) then
+** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
+** is 0.
+*/
+void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
+  Vdbe *v = pParse->pVdbe;
+  int op = 0;
+  int regFree1 = 0;
+  int regFree2 = 0;
+  int r1, r2;
+
+  assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
+  if( v==0 || pExpr==0 ) return;
+
+  /* The value of pExpr->op and op are related as follows:
+  **
+  **       pExpr->op            op
+  **       ---------          ----------
+  **       TK_ISNULL          OP_NotNull
+  **       TK_NOTNULL         OP_IsNull
+  **       TK_NE              OP_Eq
+  **       TK_EQ              OP_Ne
+  **       TK_GT              OP_Le
+  **       TK_LE              OP_Gt
+  **       TK_GE              OP_Lt
+  **       TK_LT              OP_Ge
+  **
+  ** For other values of pExpr->op, op is undefined and unused.
+  ** The value of TK_ and OP_ constants are arranged such that we
+  ** can compute the mapping above using the following expression.
+  ** Assert()s verify that the computation is correct.
+  */
+  op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
+
+  /* Verify correct alignment of TK_ and OP_ constants
+  */
+  assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
+  assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
+  assert( pExpr->op!=TK_NE || op==OP_Eq );
+  assert( pExpr->op!=TK_EQ || op==OP_Ne );
+  assert( pExpr->op!=TK_LT || op==OP_Ge );
+  assert( pExpr->op!=TK_LE || op==OP_Gt );
+  assert( pExpr->op!=TK_GT || op==OP_Le );
+  assert( pExpr->op!=TK_GE || op==OP_Lt );
+
+  switch( pExpr->op ){
+    case TK_AND: {
+      testcase( jumpIfNull==0 );
+      testcase( pParse->disableColCache==0 );
+      sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
+      pParse->disableColCache++;
+      sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
+      assert( pParse->disableColCache>0 );
+      pParse->disableColCache--;
+      break;
+    }
+    case TK_OR: {
+      int d2 = sqlite3VdbeMakeLabel(v);
+      testcase( jumpIfNull==0 );
+      testcase( pParse->disableColCache==0 );
+      sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL);
+      pParse->disableColCache++;
+      sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
+      assert( pParse->disableColCache>0 );
+      pParse->disableColCache--;
+      sqlite3VdbeResolveLabel(v, d2);
+      break;
+    }
+    case TK_NOT: {
+      sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
+      break;
+    }
+    case TK_LT:
+    case TK_LE:
+    case TK_GT:
+    case TK_GE:
+    case TK_NE:
+    case TK_EQ: {
+      testcase( op==TK_LT );
+      testcase( op==TK_LE );
+      testcase( op==TK_GT );
+      testcase( op==TK_GE );
+      testcase( op==TK_EQ );
+      testcase( op==TK_NE );
+      testcase( jumpIfNull==0 );
+      codeCompareOperands(pParse, pExpr->pLeft, &r1, &regFree1,
+                                  pExpr->pRight, &r2, &regFree2);
+      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
+                  r1, r2, dest, jumpIfNull);
+      testcase( regFree1==0 );
+      testcase( regFree2==0 );
+      break;
+    }
+    case TK_ISNULL:
+    case TK_NOTNULL: {
+      testcase( op==TK_ISNULL );
+      testcase( op==TK_NOTNULL );
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      sqlite3VdbeAddOp2(v, op, r1, dest);
+      testcase( regFree1==0 );
+      break;
+    }
+    case TK_BETWEEN: {
+      /*    x BETWEEN y AND z
+      **
+      ** Is equivalent to 
+      **
+      **    x>=y AND x<=z
+      **
+      ** Code it as such, taking care to do the common subexpression
+      ** elementation of x.
+      */
+      Expr exprAnd;
+      Expr compLeft;
+      Expr compRight;
+      Expr exprX;
+
+      exprX = *pExpr->pLeft;
+      exprAnd.op = TK_AND;
+      exprAnd.pLeft = &compLeft;
+      exprAnd.pRight = &compRight;
+      compLeft.op = TK_GE;
+      compLeft.pLeft = &exprX;
+      compLeft.pRight = pExpr->pList->a[0].pExpr;
+      compRight.op = TK_LE;
+      compRight.pLeft = &exprX;
+      compRight.pRight = pExpr->pList->a[1].pExpr;
+      exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, &regFree1);
+      testcase( regFree1==0 );
+      exprX.op = TK_REGISTER;
+      testcase( jumpIfNull==0 );
+      sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull);
+      break;
+    }
+    default: {
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
+      sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
+      testcase( regFree1==0 );
+      testcase( jumpIfNull==0 );
+      break;
+    }
+  }
+  sqlite3ReleaseTempReg(pParse, regFree1);
+  sqlite3ReleaseTempReg(pParse, regFree2);
+}
+
+/*
+** Do a deep comparison of two expression trees.  Return TRUE (non-zero)
+** if they are identical and return FALSE if they differ in any way.
+**
+** Sometimes this routine will return FALSE even if the two expressions
+** really are equivalent.  If we cannot prove that the expressions are
+** identical, we return FALSE just to be safe.  So if this routine
+** returns false, then you do not really know for certain if the two
+** expressions are the same.  But if you get a TRUE return, then you
+** can be sure the expressions are the same.  In the places where
+** this routine is used, it does not hurt to get an extra FALSE - that
+** just might result in some slightly slower code.  But returning
+** an incorrect TRUE could lead to a malfunction.
+*/
+int sqlite3ExprCompare(Expr *pA, Expr *pB){
+  int i;
+  if( pA==0||pB==0 ){
+    return pB==pA;
+  }
+  if( pA->op!=pB->op ) return 0;
+  if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 0;
+  if( !sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 0;
+  if( !sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 0;
+  if( pA->pList ){
+    if( pB->pList==0 ) return 0;
+    if( pA->pList->nExpr!=pB->pList->nExpr ) return 0;
+    for(i=0; i<pA->pList->nExpr; i++){
+      if( !sqlite3ExprCompare(pA->pList->a[i].pExpr, pB->pList->a[i].pExpr) ){
+        return 0;
+      }
+    }
+  }else if( pB->pList ){
+    return 0;
+  }
+  if( pA->pSelect || pB->pSelect ) return 0;
+  if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 0;
+  if( pA->op!=TK_COLUMN && pA->token.z ){
+    if( pB->token.z==0 ) return 0;
+    if( pB->token.n!=pA->token.n ) return 0;
+    if( sqlite3StrNICmp((char*)pA->token.z,(char*)pB->token.z,pB->token.n)!=0 ){
+      return 0;
+    }
+  }
+  return 1;
+}
+
+
+/*
+** Add a new element to the pAggInfo->aCol[] array.  Return the index of
+** the new element.  Return a negative number if malloc fails.
+*/
+static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
+  int i;
+  pInfo->aCol = sqlite3ArrayAllocate(
+       db,
+       pInfo->aCol,
+       sizeof(pInfo->aCol[0]),
+       3,
+       &pInfo->nColumn,
+       &pInfo->nColumnAlloc,
+       &i
+  );
+  return i;
+}    
+
+/*
+** Add a new element to the pAggInfo->aFunc[] array.  Return the index of
+** the new element.  Return a negative number if malloc fails.
+*/
+static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
+  int i;
+  pInfo->aFunc = sqlite3ArrayAllocate(
+       db, 
+       pInfo->aFunc,
+       sizeof(pInfo->aFunc[0]),
+       3,
+       &pInfo->nFunc,
+       &pInfo->nFuncAlloc,
+       &i
+  );
+  return i;
+}    
+
+/*
+** This is an xFunc for walkExprTree() used to implement 
+** sqlite3ExprAnalyzeAggregates().  See sqlite3ExprAnalyzeAggregates
+** for additional information.
+**
+** This routine analyzes the aggregate function at pExpr.
+*/
+static int analyzeAggregate(void *pArg, Expr *pExpr){
+  int i;
+  NameContext *pNC = (NameContext *)pArg;
+  Parse *pParse = pNC->pParse;
+  SrcList *pSrcList = pNC->pSrcList;
+  AggInfo *pAggInfo = pNC->pAggInfo;
+
+  switch( pExpr->op ){
+    case TK_AGG_COLUMN:
+    case TK_COLUMN: {
+      /* Check to see if the column is in one of the tables in the FROM
+      ** clause of the aggregate query */
+      if( pSrcList ){
+        struct SrcList_item *pItem = pSrcList->a;
+        for(i=0; i<pSrcList->nSrc; i++, pItem++){
+          struct AggInfo_col *pCol;
+          if( pExpr->iTable==pItem->iCursor ){
+            /* If we reach this point, it means that pExpr refers to a table
+            ** that is in the FROM clause of the aggregate query.  
+            **
+            ** Make an entry for the column in pAggInfo->aCol[] if there
+            ** is not an entry there already.
+            */
+            int k;
+            pCol = pAggInfo->aCol;
+            for(k=0; k<pAggInfo->nColumn; k++, pCol++){
+              if( pCol->iTable==pExpr->iTable &&
+                  pCol->iColumn==pExpr->iColumn ){
+                break;
+              }
+            }
+            if( (k>=pAggInfo->nColumn)
+             && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0 
+            ){
+              pCol = &pAggInfo->aCol[k];
+              pCol->pTab = pExpr->pTab;
+              pCol->iTable = pExpr->iTable;
+              pCol->iColumn = pExpr->iColumn;
+              pCol->iMem = ++pParse->nMem;
+              pCol->iSorterColumn = -1;
+              pCol->pExpr = pExpr;
+              if( pAggInfo->pGroupBy ){
+                int j, n;
+                ExprList *pGB = pAggInfo->pGroupBy;
+                struct ExprList_item *pTerm = pGB->a;
+                n = pGB->nExpr;
+                for(j=0; j<n; j++, pTerm++){
+                  Expr *pE = pTerm->pExpr;
+                  if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&
+                      pE->iColumn==pExpr->iColumn ){
+                    pCol->iSorterColumn = j;
+                    break;
+                  }
+                }
+              }
+              if( pCol->iSorterColumn<0 ){
+                pCol->iSorterColumn = pAggInfo->nSortingColumn++;
+              }
+            }
+            /* There is now an entry for pExpr in pAggInfo->aCol[] (either
+            ** because it was there before or because we just created it).
+            ** Convert the pExpr to be a TK_AGG_COLUMN referring to that
+            ** pAggInfo->aCol[] entry.
+            */
+            pExpr->pAggInfo = pAggInfo;
+            pExpr->op = TK_AGG_COLUMN;
+            pExpr->iAgg = k;
+            break;
+          } /* endif pExpr->iTable==pItem->iCursor */
+        } /* end loop over pSrcList */
+      }
+      return 1;
+    }
+    case TK_AGG_FUNCTION: {
+      /* The pNC->nDepth==0 test causes aggregate functions in subqueries
+      ** to be ignored */
+      if( pNC->nDepth==0 ){
+        /* Check to see if pExpr is a duplicate of another aggregate 
+        ** function that is already in the pAggInfo structure
+        */
+        struct AggInfo_func *pItem = pAggInfo->aFunc;
+        for(i=0; i<pAggInfo->nFunc; i++, pItem++){
+          if( sqlite3ExprCompare(pItem->pExpr, pExpr) ){
+            break;
+          }
+        }
+        if( i>=pAggInfo->nFunc ){
+          /* pExpr is original.  Make a new entry in pAggInfo->aFunc[]
+          */
+          u8 enc = ENC(pParse->db);
+          i = addAggInfoFunc(pParse->db, pAggInfo);
+          if( i>=0 ){
+            pItem = &pAggInfo->aFunc[i];
+            pItem->pExpr = pExpr;
+            pItem->iMem = ++pParse->nMem;
+            pItem->pFunc = sqlite3FindFunction(pParse->db,
+                   (char*)pExpr->token.z, pExpr->token.n,
+                   pExpr->pList ? pExpr->pList->nExpr : 0, enc, 0);
+            if( pExpr->flags & EP_Distinct ){
+              pItem->iDistinct = pParse->nTab++;
+            }else{
+              pItem->iDistinct = -1;
+            }
+          }
+        }
+        /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
+        */
+        pExpr->iAgg = i;
+        pExpr->pAggInfo = pAggInfo;
+        return 1;
+      }
+    }
+  }
+
+  /* Recursively walk subqueries looking for TK_COLUMN nodes that need
+  ** to be changed to TK_AGG_COLUMN.  But increment nDepth so that
+  ** TK_AGG_FUNCTION nodes in subqueries will be unchanged.
+  */
+  if( pExpr->pSelect ){
+    pNC->nDepth++;
+    walkSelectExpr(pExpr->pSelect, analyzeAggregate, pNC);
+    pNC->nDepth--;
+  }
+  return 0;
+}
+
+/*
+** Analyze the given expression looking for aggregate functions and
+** for variables that need to be added to the pParse->aAgg[] array.
+** Make additional entries to the pParse->aAgg[] array as necessary.
+**
+** This routine should only be called after the expression has been
+** analyzed by sqlite3ExprResolveNames().
+*/
+void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
+  walkExprTree(pExpr, analyzeAggregate, pNC);
+}
+
+/*
+** Call sqlite3ExprAnalyzeAggregates() for every expression in an
+** expression list.  Return the number of errors.
+**
+** If an error is found, the analysis is cut short.
+*/
+void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
+  struct ExprList_item *pItem;
+  int i;
+  if( pList ){
+    for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
+      sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
+    }
+  }
+}
+
+/*
+** Allocate or deallocate temporary use registers during code generation.
+*/
+int sqlite3GetTempReg(Parse *pParse){
+  if( pParse->nTempReg==0 ){
+    return ++pParse->nMem;
+  }
+  return pParse->aTempReg[--pParse->nTempReg];
+}
+void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
+  if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){
+    sqlite3ExprWritableRegister(pParse, iReg, iReg);
+    pParse->aTempReg[pParse->nTempReg++] = iReg;
+  }
+}
+
+/*
+** Allocate or deallocate a block of nReg consecutive registers
+*/
+int sqlite3GetTempRange(Parse *pParse, int nReg){
+  int i, n;
+  i = pParse->iRangeReg;
+  n = pParse->nRangeReg;
+  if( nReg<=n && !usedAsColumnCache(pParse, i, i+n-1) ){
+    pParse->iRangeReg += nReg;
+    pParse->nRangeReg -= nReg;
+  }else{
+    i = pParse->nMem+1;
+    pParse->nMem += nReg;
+  }
+  return i;
+}
+void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
+  if( nReg>pParse->nRangeReg ){
+    pParse->nRangeReg = nReg;
+    pParse->iRangeReg = iReg;
+  }
+}
diff --git a/third_party/sqlite/src/fault.c b/third_party/sqlite/src/fault.c
new file mode 100755
index 0000000..5ede8b9
--- /dev/null
+++ b/third_party/sqlite/src/fault.c
@@ -0,0 +1,71 @@
+/*
+** 2008 Jan 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** $Id: fault.c,v 1.10 2008/06/22 12:37:58 drh Exp $
+*/
+
+/*
+** This file contains code to support the concept of "benign" 
+** malloc failures (when the xMalloc() or xRealloc() method of the
+** sqlite3_mem_methods structure fails to allocate a block of memory
+** and returns 0). 
+**
+** Most malloc failures are non-benign. After they occur, SQLite
+** abandons the current operation and returns an error code (usually
+** SQLITE_NOMEM) to the user. However, sometimes a fault is not necessarily
+** fatal. For example, if a malloc fails while resizing a hash table, this 
+** is completely recoverable simply by not carrying out the resize. The 
+** hash table will continue to function normally.  So a malloc failure 
+** during a hash table resize is a benign fault.
+*/
+
+#include "sqliteInt.h"
+
+#ifndef SQLITE_OMIT_BUILTIN_TEST
+
+/*
+** Global variables.
+*/
+static struct BenignMallocHooks {
+  void (*xBenignBegin)(void);
+  void (*xBenignEnd)(void);
+} hooks;
+
+/*
+** Register hooks to call when sqlite3BeginBenignMalloc() and
+** sqlite3EndBenignMalloc() are called, respectively.
+*/
+void sqlite3BenignMallocHooks(
+  void (*xBenignBegin)(void),
+  void (*xBenignEnd)(void)
+){
+  hooks.xBenignBegin = xBenignBegin;
+  hooks.xBenignEnd = xBenignEnd;
+}
+
+/*
+** This (sqlite3EndBenignMalloc()) is called by SQLite code to indicate that
+** subsequent malloc failures are benign. A call to sqlite3EndBenignMalloc()
+** indicates that subsequent malloc failures are non-benign.
+*/
+void sqlite3BeginBenignMalloc(void){
+  if( hooks.xBenignBegin ){
+    hooks.xBenignBegin();
+  }
+}
+void sqlite3EndBenignMalloc(void){
+  if( hooks.xBenignEnd ){
+    hooks.xBenignEnd();
+  }
+}
+
+#endif   /* #ifndef SQLITE_OMIT_BUILTIN_TEST */
diff --git a/third_party/sqlite/src/func.c b/third_party/sqlite/src/func.c
new file mode 100755
index 0000000..7316c74
--- /dev/null
+++ b/third_party/sqlite/src/func.c
@@ -0,0 +1,1399 @@
+/*
+** 2002 February 23
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the C functions that implement various SQL
+** functions of SQLite.  
+**
+** There is only one exported symbol in this file - the function
+** sqliteRegisterBuildinFunctions() found at the bottom of the file.
+** All other code has file scope.
+**
+** $Id: func.c,v 1.196 2008/07/28 19:34:53 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+#include <stdlib.h>
+#include <assert.h>
+#include "vdbeInt.h"
+
+
+/*
+** Return the collating function associated with a function.
+*/
+static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){
+  return context->pColl;
+}
+
+/*
+** Implementation of the non-aggregate min() and max() functions
+*/
+static void minmaxFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int i;
+  int mask;    /* 0 for min() or 0xffffffff for max() */
+  int iBest;
+  CollSeq *pColl;
+
+  if( argc==0 ) return;
+  mask = sqlite3_user_data(context)==0 ? 0 : -1;
+  pColl = sqlite3GetFuncCollSeq(context);
+  assert( pColl );
+  assert( mask==-1 || mask==0 );
+  iBest = 0;
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  for(i=1; i<argc; i++){
+    if( sqlite3_value_type(argv[i])==SQLITE_NULL ) return;
+    if( (sqlite3MemCompare(argv[iBest], argv[i], pColl)^mask)>=0 ){
+      iBest = i;
+    }
+  }
+  sqlite3_result_value(context, argv[iBest]);
+}
+
+/*
+** Return the type of the argument.
+*/
+static void typeofFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const char *z = 0;
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_NULL:    z = "null";    break;
+    case SQLITE_INTEGER: z = "integer"; break;
+    case SQLITE_TEXT:    z = "text";    break;
+    case SQLITE_FLOAT:   z = "real";    break;
+    case SQLITE_BLOB:    z = "blob";    break;
+  }
+  sqlite3_result_text(context, z, -1, SQLITE_STATIC);
+}
+
+
+/*
+** Implementation of the length() function
+*/
+static void lengthFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int len;
+
+  assert( argc==1 );
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_BLOB:
+    case SQLITE_INTEGER:
+    case SQLITE_FLOAT: {
+      sqlite3_result_int(context, sqlite3_value_bytes(argv[0]));
+      break;
+    }
+    case SQLITE_TEXT: {
+      const unsigned char *z = sqlite3_value_text(argv[0]);
+      if( z==0 ) return;
+      len = 0;
+      while( *z ){
+        len++;
+        SQLITE_SKIP_UTF8(z);
+      }
+      sqlite3_result_int(context, len);
+      break;
+    }
+    default: {
+      sqlite3_result_null(context);
+      break;
+    }
+  }
+}
+
+/*
+** Implementation of the abs() function
+*/
+static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  assert( argc==1 );
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_INTEGER: {
+      i64 iVal = sqlite3_value_int64(argv[0]);
+      if( iVal<0 ){
+        if( (iVal<<1)==0 ){
+          sqlite3_result_error(context, "integer overflow", -1);
+          return;
+        }
+        iVal = -iVal;
+      } 
+      sqlite3_result_int64(context, iVal);
+      break;
+    }
+    case SQLITE_NULL: {
+      sqlite3_result_null(context);
+      break;
+    }
+    default: {
+      double rVal = sqlite3_value_double(argv[0]);
+      if( rVal<0 ) rVal = -rVal;
+      sqlite3_result_double(context, rVal);
+      break;
+    }
+  }
+}
+
+/*
+** Implementation of the substr() function.
+**
+** substr(x,p1,p2)  returns p2 characters of x[] beginning with p1.
+** p1 is 1-indexed.  So substr(x,1,1) returns the first character
+** of x.  If x is text, then we actually count UTF-8 characters.
+** If x is a blob, then we count bytes.
+**
+** If p1 is negative, then we begin abs(p1) from the end of x[].
+*/
+static void substrFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *z;
+  const unsigned char *z2;
+  int len;
+  int p0type;
+  i64 p1, p2;
+
+  assert( argc==3 || argc==2 );
+  p0type = sqlite3_value_type(argv[0]);
+  if( p0type==SQLITE_BLOB ){
+    len = sqlite3_value_bytes(argv[0]);
+    z = sqlite3_value_blob(argv[0]);
+    if( z==0 ) return;
+    assert( len==sqlite3_value_bytes(argv[0]) );
+  }else{
+    z = sqlite3_value_text(argv[0]);
+    if( z==0 ) return;
+    len = 0;
+    for(z2=z; *z2; len++){
+      SQLITE_SKIP_UTF8(z2);
+    }
+  }
+  p1 = sqlite3_value_int(argv[1]);
+  if( argc==3 ){
+    p2 = sqlite3_value_int(argv[2]);
+  }else{
+    p2 = sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH];
+  }
+  if( p1<0 ){
+    p1 += len;
+    if( p1<0 ){
+      p2 += p1;
+      p1 = 0;
+    }
+  }else if( p1>0 ){
+    p1--;
+  }
+  if( p1+p2>len ){
+    p2 = len-p1;
+  }
+  if( p0type!=SQLITE_BLOB ){
+    while( *z && p1 ){
+      SQLITE_SKIP_UTF8(z);
+      p1--;
+    }
+    for(z2=z; *z2 && p2; p2--){
+      SQLITE_SKIP_UTF8(z2);
+    }
+    sqlite3_result_text(context, (char*)z, z2-z, SQLITE_TRANSIENT);
+  }else{
+    if( p2<0 ) p2 = 0;
+    sqlite3_result_blob(context, (char*)&z[p1], p2, SQLITE_TRANSIENT);
+  }
+}
+
+/*
+** Implementation of the round() function
+*/
+static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  int n = 0;
+  double r;
+  char zBuf[500];  /* larger than the %f representation of the largest double */
+  assert( argc==1 || argc==2 );
+  if( argc==2 ){
+    if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return;
+    n = sqlite3_value_int(argv[1]);
+    if( n>30 ) n = 30;
+    if( n<0 ) n = 0;
+  }
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  r = sqlite3_value_double(argv[0]);
+  sqlite3_snprintf(sizeof(zBuf),zBuf,"%.*f",n,r);
+  sqlite3AtoF(zBuf, &r);
+  sqlite3_result_double(context, r);
+}
+
+/*
+** Allocate nByte bytes of space using sqlite3_malloc(). If the
+** allocation fails, call sqlite3_result_error_nomem() to notify
+** the database handle that malloc() has failed.
+*/
+static void *contextMalloc(sqlite3_context *context, i64 nByte){
+  char *z;
+  if( nByte>sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH] ){
+    sqlite3_result_error_toobig(context);
+    z = 0;
+  }else{
+    z = sqlite3Malloc(nByte);
+    if( !z && nByte>0 ){
+      sqlite3_result_error_nomem(context);
+    }
+  }
+  return z;
+}
+
+/*
+** Implementation of the upper() and lower() SQL functions.
+*/
+static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  char *z1;
+  const char *z2;
+  int i, n;
+  if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
+  z2 = (char*)sqlite3_value_text(argv[0]);
+  n = sqlite3_value_bytes(argv[0]);
+  /* Verify that the call to _bytes() does not invalidate the _text() pointer */
+  assert( z2==(char*)sqlite3_value_text(argv[0]) );
+  if( z2 ){
+    z1 = contextMalloc(context, ((i64)n)+1);
+    if( z1 ){
+      memcpy(z1, z2, n+1);
+      for(i=0; z1[i]; i++){
+        z1[i] = toupper(z1[i]);
+      }
+      sqlite3_result_text(context, z1, -1, sqlite3_free);
+    }
+  }
+}
+static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  char *z1;
+  const char *z2;
+  int i, n;
+  if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
+  z2 = (char*)sqlite3_value_text(argv[0]);
+  n = sqlite3_value_bytes(argv[0]);
+  /* Verify that the call to _bytes() does not invalidate the _text() pointer */
+  assert( z2==(char*)sqlite3_value_text(argv[0]) );
+  if( z2 ){
+    z1 = contextMalloc(context, ((i64)n)+1);
+    if( z1 ){
+      memcpy(z1, z2, n+1);
+      for(i=0; z1[i]; i++){
+        z1[i] = tolower(z1[i]);
+      }
+      sqlite3_result_text(context, z1, -1, sqlite3_free);
+    }
+  }
+}
+
+/*
+** Implementation of the IFNULL(), NVL(), and COALESCE() functions.  
+** All three do the same thing.  They return the first non-NULL
+** argument.
+*/
+static void ifnullFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int i;
+  for(i=0; i<argc; i++){
+    if( SQLITE_NULL!=sqlite3_value_type(argv[i]) ){
+      sqlite3_result_value(context, argv[i]);
+      break;
+    }
+  }
+}
+
+/*
+** Implementation of random().  Return a random integer.  
+*/
+static void randomFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  sqlite_int64 r;
+  sqlite3_randomness(sizeof(r), &r);
+  if( (r<<1)==0 ) r = 0;  /* Prevent 0x8000.... as the result so that we */
+                          /* can always do abs() of the result */
+  sqlite3_result_int64(context, r);
+}
+
+/*
+** Implementation of randomblob(N).  Return a random blob
+** that is N bytes long.
+*/
+static void randomBlob(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int n;
+  unsigned char *p;
+  assert( argc==1 );
+  n = sqlite3_value_int(argv[0]);
+  if( n<1 ){
+    n = 1;
+  }
+  p = contextMalloc(context, n);
+  if( p ){
+    sqlite3_randomness(n, p);
+    sqlite3_result_blob(context, (char*)p, n, sqlite3_free);
+  }
+}
+
+/*
+** Implementation of the last_insert_rowid() SQL function.  The return
+** value is the same as the sqlite3_last_insert_rowid() API function.
+*/
+static void last_insert_rowid(
+  sqlite3_context *context, 
+  int arg, 
+  sqlite3_value **argv
+){
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  sqlite3_result_int64(context, sqlite3_last_insert_rowid(db));
+}
+
+/*
+** Implementation of the changes() SQL function.  The return value is the
+** same as the sqlite3_changes() API function.
+*/
+static void changes(
+  sqlite3_context *context,
+  int arg,
+  sqlite3_value **argv
+){
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  sqlite3_result_int(context, sqlite3_changes(db));
+}
+
+/*
+** Implementation of the total_changes() SQL function.  The return value is
+** the same as the sqlite3_total_changes() API function.
+*/
+static void total_changes(
+  sqlite3_context *context,
+  int arg,
+  sqlite3_value **argv
+){
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  sqlite3_result_int(context, sqlite3_total_changes(db));
+}
+
+/*
+** A structure defining how to do GLOB-style comparisons.
+*/
+struct compareInfo {
+  u8 matchAll;
+  u8 matchOne;
+  u8 matchSet;
+  u8 noCase;
+};
+
+/*
+** For LIKE and GLOB matching on EBCDIC machines, assume that every
+** character is exactly one byte in size.  Also, all characters are
+** able to participate in upper-case-to-lower-case mappings in EBCDIC
+** whereas only characters less than 0x80 do in ASCII.
+*/
+#if defined(SQLITE_EBCDIC)
+# define sqlite3Utf8Read(A,B,C)  (*(A++))
+# define GlogUpperToLower(A)     A = sqlite3UpperToLower[A]
+#else
+# define GlogUpperToLower(A)     if( A<0x80 ){ A = sqlite3UpperToLower[A]; }
+#endif
+
+static const struct compareInfo globInfo = { '*', '?', '[', 0 };
+/* The correct SQL-92 behavior is for the LIKE operator to ignore
+** case.  Thus  'a' LIKE 'A' would be true. */
+static const struct compareInfo likeInfoNorm = { '%', '_',   0, 1 };
+/* If SQLITE_CASE_SENSITIVE_LIKE is defined, then the LIKE operator
+** is case sensitive causing 'a' LIKE 'A' to be false */
+static const struct compareInfo likeInfoAlt = { '%', '_',   0, 0 };
+
+/*
+** Compare two UTF-8 strings for equality where the first string can
+** potentially be a "glob" expression.  Return true (1) if they
+** are the same and false (0) if they are different.
+**
+** Globbing rules:
+**
+**      '*'       Matches any sequence of zero or more characters.
+**
+**      '?'       Matches exactly one character.
+**
+**     [...]      Matches one character from the enclosed list of
+**                characters.
+**
+**     [^...]     Matches one character not in the enclosed list.
+**
+** With the [...] and [^...] matching, a ']' character can be included
+** in the list by making it the first character after '[' or '^'.  A
+** range of characters can be specified using '-'.  Example:
+** "[a-z]" matches any single lower-case letter.  To match a '-', make
+** it the last character in the list.
+**
+** This routine is usually quick, but can be N**2 in the worst case.
+**
+** Hints: to match '*' or '?', put them in "[]".  Like this:
+**
+**         abc[*]xyz        Matches "abc*xyz" only
+*/
+static int patternCompare(
+  const u8 *zPattern,              /* The glob pattern */
+  const u8 *zString,               /* The string to compare against the glob */
+  const struct compareInfo *pInfo, /* Information about how to do the compare */
+  const int esc                    /* The escape character */
+){
+  int c, c2;
+  int invert;
+  int seen;
+  u8 matchOne = pInfo->matchOne;
+  u8 matchAll = pInfo->matchAll;
+  u8 matchSet = pInfo->matchSet;
+  u8 noCase = pInfo->noCase; 
+  int prevEscape = 0;     /* True if the previous character was 'escape' */
+
+  while( (c = sqlite3Utf8Read(zPattern,0,&zPattern))!=0 ){
+    if( !prevEscape && c==matchAll ){
+      while( (c=sqlite3Utf8Read(zPattern,0,&zPattern)) == matchAll
+               || c == matchOne ){
+        if( c==matchOne && sqlite3Utf8Read(zString, 0, &zString)==0 ){
+          return 0;
+        }
+      }
+      if( c==0 ){
+        return 1;
+      }else if( c==esc ){
+        c = sqlite3Utf8Read(zPattern, 0, &zPattern);
+        if( c==0 ){
+          return 0;
+        }
+      }else if( c==matchSet ){
+        assert( esc==0 );         /* This is GLOB, not LIKE */
+        assert( matchSet<0x80 );  /* '[' is a single-byte character */
+        while( *zString && patternCompare(&zPattern[-1],zString,pInfo,esc)==0 ){
+          SQLITE_SKIP_UTF8(zString);
+        }
+        return *zString!=0;
+      }
+      while( (c2 = sqlite3Utf8Read(zString,0,&zString))!=0 ){
+        if( noCase ){
+          GlogUpperToLower(c2);
+          GlogUpperToLower(c);
+          while( c2 != 0 && c2 != c ){
+            c2 = sqlite3Utf8Read(zString, 0, &zString);
+            GlogUpperToLower(c2);
+          }
+        }else{
+          while( c2 != 0 && c2 != c ){
+            c2 = sqlite3Utf8Read(zString, 0, &zString);
+          }
+        }
+        if( c2==0 ) return 0;
+        if( patternCompare(zPattern,zString,pInfo,esc) ) return 1;
+      }
+      return 0;
+    }else if( !prevEscape && c==matchOne ){
+      if( sqlite3Utf8Read(zString, 0, &zString)==0 ){
+        return 0;
+      }
+    }else if( c==matchSet ){
+      int prior_c = 0;
+      assert( esc==0 );    /* This only occurs for GLOB, not LIKE */
+      seen = 0;
+      invert = 0;
+      c = sqlite3Utf8Read(zString, 0, &zString);
+      if( c==0 ) return 0;
+      c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
+      if( c2=='^' ){
+        invert = 1;
+        c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
+      }
+      if( c2==']' ){
+        if( c==']' ) seen = 1;
+        c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
+      }
+      while( c2 && c2!=']' ){
+        if( c2=='-' && zPattern[0]!=']' && zPattern[0]!=0 && prior_c>0 ){
+          c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
+          if( c>=prior_c && c<=c2 ) seen = 1;
+          prior_c = 0;
+        }else{
+          if( c==c2 ){
+            seen = 1;
+          }
+          prior_c = c2;
+        }
+        c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
+      }
+      if( c2==0 || (seen ^ invert)==0 ){
+        return 0;
+      }
+    }else if( esc==c && !prevEscape ){
+      prevEscape = 1;
+    }else{
+      c2 = sqlite3Utf8Read(zString, 0, &zString);
+      if( noCase ){
+        GlogUpperToLower(c);
+        GlogUpperToLower(c2);
+      }
+      if( c!=c2 ){
+        return 0;
+      }
+      prevEscape = 0;
+    }
+  }
+  return *zString==0;
+}
+
+/*
+** Count the number of times that the LIKE operator (or GLOB which is
+** just a variation of LIKE) gets called.  This is used for testing
+** only.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_like_count = 0;
+#endif
+
+
+/*
+** Implementation of the like() SQL function.  This function implements
+** the build-in LIKE operator.  The first argument to the function is the
+** pattern and the second argument is the string.  So, the SQL statements:
+**
+**       A LIKE B
+**
+** is implemented as like(B,A).
+**
+** This same function (with a different compareInfo structure) computes
+** the GLOB operator.
+*/
+static void likeFunc(
+  sqlite3_context *context, 
+  int argc, 
+  sqlite3_value **argv
+){
+  const unsigned char *zA, *zB;
+  int escape = 0;
+  sqlite3 *db = sqlite3_context_db_handle(context);
+
+  zB = sqlite3_value_text(argv[0]);
+  zA = sqlite3_value_text(argv[1]);
+
+  /* Limit the length of the LIKE or GLOB pattern to avoid problems
+  ** of deep recursion and N*N behavior in patternCompare().
+  */
+  if( sqlite3_value_bytes(argv[0]) >
+        db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] ){
+    sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1);
+    return;
+  }
+  assert( zB==sqlite3_value_text(argv[0]) );  /* Encoding did not change */
+
+  if( argc==3 ){
+    /* The escape character string must consist of a single UTF-8 character.
+    ** Otherwise, return an error.
+    */
+    const unsigned char *zEsc = sqlite3_value_text(argv[2]);
+    if( zEsc==0 ) return;
+    if( sqlite3Utf8CharLen((char*)zEsc, -1)!=1 ){
+      sqlite3_result_error(context, 
+          "ESCAPE expression must be a single character", -1);
+      return;
+    }
+    escape = sqlite3Utf8Read(zEsc, 0, &zEsc);
+  }
+  if( zA && zB ){
+    struct compareInfo *pInfo = sqlite3_user_data(context);
+#ifdef SQLITE_TEST
+    sqlite3_like_count++;
+#endif
+    
+    sqlite3_result_int(context, patternCompare(zB, zA, pInfo, escape));
+  }
+}
+
+/*
+** Implementation of the NULLIF(x,y) function.  The result is the first
+** argument if the arguments are different.  The result is NULL if the
+** arguments are equal to each other.
+*/
+static void nullifFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  CollSeq *pColl = sqlite3GetFuncCollSeq(context);
+  if( sqlite3MemCompare(argv[0], argv[1], pColl)!=0 ){
+    sqlite3_result_value(context, argv[0]);
+  }
+}
+
+/*
+** Implementation of the VERSION(*) function.  The result is the version
+** of the SQLite library that is running.
+*/
+static void versionFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  sqlite3_result_text(context, sqlite3_version, -1, SQLITE_STATIC);
+}
+
+/* Array for converting from half-bytes (nybbles) into ASCII hex
+** digits. */
+static const char hexdigits[] = {
+  '0', '1', '2', '3', '4', '5', '6', '7',
+  '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' 
+};
+
+/*
+** EXPERIMENTAL - This is not an official function.  The interface may
+** change.  This function may disappear.  Do not write code that depends
+** on this function.
+**
+** Implementation of the QUOTE() function.  This function takes a single
+** argument.  If the argument is numeric, the return value is the same as
+** the argument.  If the argument is NULL, the return value is the string
+** "NULL".  Otherwise, the argument is enclosed in single quotes with
+** single-quote escapes.
+*/
+static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  if( argc<1 ) return;
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_NULL: {
+      sqlite3_result_text(context, "NULL", 4, SQLITE_STATIC);
+      break;
+    }
+    case SQLITE_INTEGER:
+    case SQLITE_FLOAT: {
+      sqlite3_result_value(context, argv[0]);
+      break;
+    }
+    case SQLITE_BLOB: {
+      char *zText = 0;
+      char const *zBlob = sqlite3_value_blob(argv[0]);
+      int nBlob = sqlite3_value_bytes(argv[0]);
+      assert( zBlob==sqlite3_value_blob(argv[0]) ); /* No encoding change */
+      zText = (char *)contextMalloc(context, (2*(i64)nBlob)+4); 
+      if( zText ){
+        int i;
+        for(i=0; i<nBlob; i++){
+          zText[(i*2)+2] = hexdigits[(zBlob[i]>>4)&0x0F];
+          zText[(i*2)+3] = hexdigits[(zBlob[i])&0x0F];
+        }
+        zText[(nBlob*2)+2] = '\'';
+        zText[(nBlob*2)+3] = '\0';
+        zText[0] = 'X';
+        zText[1] = '\'';
+        sqlite3_result_text(context, zText, -1, SQLITE_TRANSIENT);
+        sqlite3_free(zText);
+      }
+      break;
+    }
+    case SQLITE_TEXT: {
+      int i,j;
+      u64 n;
+      const unsigned char *zArg = sqlite3_value_text(argv[0]);
+      char *z;
+
+      if( zArg==0 ) return;
+      for(i=0, n=0; zArg[i]; i++){ if( zArg[i]=='\'' ) n++; }
+      z = contextMalloc(context, ((i64)i)+((i64)n)+3);
+      if( z ){
+        z[0] = '\'';
+        for(i=0, j=1; zArg[i]; i++){
+          z[j++] = zArg[i];
+          if( zArg[i]=='\'' ){
+            z[j++] = '\'';
+          }
+        }
+        z[j++] = '\'';
+        z[j] = 0;
+        sqlite3_result_text(context, z, j, sqlite3_free);
+      }
+    }
+  }
+}
+
+/*
+** The hex() function.  Interpret the argument as a blob.  Return
+** a hexadecimal rendering as text.
+*/
+static void hexFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int i, n;
+  const unsigned char *pBlob;
+  char *zHex, *z;
+  assert( argc==1 );
+  pBlob = sqlite3_value_blob(argv[0]);
+  n = sqlite3_value_bytes(argv[0]);
+  assert( pBlob==sqlite3_value_blob(argv[0]) );  /* No encoding change */
+  z = zHex = contextMalloc(context, ((i64)n)*2 + 1);
+  if( zHex ){
+    for(i=0; i<n; i++, pBlob++){
+      unsigned char c = *pBlob;
+      *(z++) = hexdigits[(c>>4)&0xf];
+      *(z++) = hexdigits[c&0xf];
+    }
+    *z = 0;
+    sqlite3_result_text(context, zHex, n*2, sqlite3_free);
+  }
+}
+
+/*
+** The zeroblob(N) function returns a zero-filled blob of size N bytes.
+*/
+static void zeroblobFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  i64 n;
+  assert( argc==1 );
+  n = sqlite3_value_int64(argv[0]);
+  if( n>SQLITE_MAX_LENGTH ){
+    sqlite3_result_error_toobig(context);
+  }else{
+    sqlite3_result_zeroblob(context, n);
+  }
+}
+
+/*
+** The replace() function.  Three arguments are all strings: call
+** them A, B, and C. The result is also a string which is derived
+** from A by replacing every occurance of B with C.  The match
+** must be exact.  Collating sequences are not used.
+*/
+static void replaceFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *zStr;        /* The input string A */
+  const unsigned char *zPattern;    /* The pattern string B */
+  const unsigned char *zRep;        /* The replacement string C */
+  unsigned char *zOut;              /* The output */
+  int nStr;                /* Size of zStr */
+  int nPattern;            /* Size of zPattern */
+  int nRep;                /* Size of zRep */
+  i64 nOut;                /* Maximum size of zOut */
+  int loopLimit;           /* Last zStr[] that might match zPattern[] */
+  int i, j;                /* Loop counters */
+
+  assert( argc==3 );
+  zStr = sqlite3_value_text(argv[0]);
+  if( zStr==0 ) return;
+  nStr = sqlite3_value_bytes(argv[0]);
+  assert( zStr==sqlite3_value_text(argv[0]) );  /* No encoding change */
+  zPattern = sqlite3_value_text(argv[1]);
+  if( zPattern==0 || zPattern[0]==0 ) return;
+  nPattern = sqlite3_value_bytes(argv[1]);
+  assert( zPattern==sqlite3_value_text(argv[1]) );  /* No encoding change */
+  zRep = sqlite3_value_text(argv[2]);
+  if( zRep==0 ) return;
+  nRep = sqlite3_value_bytes(argv[2]);
+  assert( zRep==sqlite3_value_text(argv[2]) );
+  nOut = nStr + 1;
+  assert( nOut<SQLITE_MAX_LENGTH );
+  zOut = contextMalloc(context, (i64)nOut);
+  if( zOut==0 ){
+    return;
+  }
+  loopLimit = nStr - nPattern;  
+  for(i=j=0; i<=loopLimit; i++){
+    if( zStr[i]!=zPattern[0] || memcmp(&zStr[i], zPattern, nPattern) ){
+      zOut[j++] = zStr[i];
+    }else{
+      u8 *zOld;
+      sqlite3 *db = sqlite3_context_db_handle(context);
+      nOut += nRep - nPattern;
+      if( nOut>=db->aLimit[SQLITE_LIMIT_LENGTH] ){
+        sqlite3_result_error_toobig(context);
+        sqlite3DbFree(db, zOut);
+        return;
+      }
+      zOld = zOut;
+      zOut = sqlite3_realloc(zOut, (int)nOut);
+      if( zOut==0 ){
+        sqlite3_result_error_nomem(context);
+        sqlite3DbFree(db, zOld);
+        return;
+      }
+      memcpy(&zOut[j], zRep, nRep);
+      j += nRep;
+      i += nPattern-1;
+    }
+  }
+  assert( j+nStr-i+1==nOut );
+  memcpy(&zOut[j], &zStr[i], nStr-i);
+  j += nStr - i;
+  assert( j<=nOut );
+  zOut[j] = 0;
+  sqlite3_result_text(context, (char*)zOut, j, sqlite3_free);
+}
+
+/*
+** Implementation of the TRIM(), LTRIM(), and RTRIM() functions.
+** The userdata is 0x1 for left trim, 0x2 for right trim, 0x3 for both.
+*/
+static void trimFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *zIn;         /* Input string */
+  const unsigned char *zCharSet;    /* Set of characters to trim */
+  int nIn;                          /* Number of bytes in input */
+  int flags;                        /* 1: trimleft  2: trimright  3: trim */
+  int i;                            /* Loop counter */
+  unsigned char *aLen;              /* Length of each character in zCharSet */
+  unsigned char **azChar;           /* Individual characters in zCharSet */
+  int nChar;                        /* Number of characters in zCharSet */
+
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
+    return;
+  }
+  zIn = sqlite3_value_text(argv[0]);
+  if( zIn==0 ) return;
+  nIn = sqlite3_value_bytes(argv[0]);
+  assert( zIn==sqlite3_value_text(argv[0]) );
+  if( argc==1 ){
+    static const unsigned char lenOne[] = { 1 };
+    static const unsigned char *azOne[] = { (u8*)" " };
+    nChar = 1;
+    aLen = (u8*)lenOne;
+    azChar = (unsigned char **)azOne;
+    zCharSet = 0;
+  }else if( (zCharSet = sqlite3_value_text(argv[1]))==0 ){
+    return;
+  }else{
+    const unsigned char *z;
+    for(z=zCharSet, nChar=0; *z; nChar++){
+      SQLITE_SKIP_UTF8(z);
+    }
+    if( nChar>0 ){
+      azChar = contextMalloc(context, ((i64)nChar)*(sizeof(char*)+1));
+      if( azChar==0 ){
+        return;
+      }
+      aLen = (unsigned char*)&azChar[nChar];
+      for(z=zCharSet, nChar=0; *z; nChar++){
+        azChar[nChar] = (unsigned char *)z;
+        SQLITE_SKIP_UTF8(z);
+        aLen[nChar] = z - azChar[nChar];
+      }
+    }
+  }
+  if( nChar>0 ){
+    flags = SQLITE_PTR_TO_INT(sqlite3_user_data(context));
+    if( flags & 1 ){
+      while( nIn>0 ){
+        int len;
+        for(i=0; i<nChar; i++){
+          len = aLen[i];
+          if( memcmp(zIn, azChar[i], len)==0 ) break;
+        }
+        if( i>=nChar ) break;
+        zIn += len;
+        nIn -= len;
+      }
+    }
+    if( flags & 2 ){
+      while( nIn>0 ){
+        int len;
+        for(i=0; i<nChar; i++){
+          len = aLen[i];
+          if( len<=nIn && memcmp(&zIn[nIn-len],azChar[i],len)==0 ) break;
+        }
+        if( i>=nChar ) break;
+        nIn -= len;
+      }
+    }
+    if( zCharSet ){
+      sqlite3_free((void*)azChar);
+    }
+  }
+  sqlite3_result_text(context, (char*)zIn, nIn, SQLITE_TRANSIENT);
+}
+
+#ifdef SQLITE_SOUNDEX
+/*
+** Compute the soundex encoding of a word.
+*/
+static void soundexFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  char zResult[8];
+  const u8 *zIn;
+  int i, j;
+  static const unsigned char iCode[] = {
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
+    1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
+    0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
+    1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
+  };
+  assert( argc==1 );
+  zIn = (u8*)sqlite3_value_text(argv[0]);
+  if( zIn==0 ) zIn = (u8*)"";
+  for(i=0; zIn[i] && !isalpha(zIn[i]); i++){}
+  if( zIn[i] ){
+    u8 prevcode = iCode[zIn[i]&0x7f];
+    zResult[0] = toupper(zIn[i]);
+    for(j=1; j<4 && zIn[i]; i++){
+      int code = iCode[zIn[i]&0x7f];
+      if( code>0 ){
+        if( code!=prevcode ){
+          prevcode = code;
+          zResult[j++] = code + '0';
+        }
+      }else{
+        prevcode = 0;
+      }
+    }
+    while( j<4 ){
+      zResult[j++] = '0';
+    }
+    zResult[j] = 0;
+    sqlite3_result_text(context, zResult, 4, SQLITE_TRANSIENT);
+  }else{
+    sqlite3_result_text(context, "?000", 4, SQLITE_STATIC);
+  }
+}
+#endif
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+/*
+** A function that loads a shared-library extension then returns NULL.
+*/
+static void loadExt(sqlite3_context *context, int argc, sqlite3_value **argv){
+  const char *zFile = (const char *)sqlite3_value_text(argv[0]);
+  const char *zProc;
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  char *zErrMsg = 0;
+
+  if( argc==2 ){
+    zProc = (const char *)sqlite3_value_text(argv[1]);
+  }else{
+    zProc = 0;
+  }
+  if( zFile && sqlite3_load_extension(db, zFile, zProc, &zErrMsg) ){
+    sqlite3_result_error(context, zErrMsg, -1);
+    sqlite3_free(zErrMsg);
+  }
+}
+#endif
+
+
+/*
+** An instance of the following structure holds the context of a
+** sum() or avg() aggregate computation.
+*/
+typedef struct SumCtx SumCtx;
+struct SumCtx {
+  double rSum;      /* Floating point sum */
+  i64 iSum;         /* Integer sum */   
+  i64 cnt;          /* Number of elements summed */
+  u8 overflow;      /* True if integer overflow seen */
+  u8 approx;        /* True if non-integer value was input to the sum */
+};
+
+/*
+** Routines used to compute the sum, average, and total.
+**
+** The SUM() function follows the (broken) SQL standard which means
+** that it returns NULL if it sums over no inputs.  TOTAL returns
+** 0.0 in that case.  In addition, TOTAL always returns a float where
+** SUM might return an integer if it never encounters a floating point
+** value.  TOTAL never fails, but SUM might through an exception if
+** it overflows an integer.
+*/
+static void sumStep(sqlite3_context *context, int argc, sqlite3_value **argv){
+  SumCtx *p;
+  int type;
+  assert( argc==1 );
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  type = sqlite3_value_numeric_type(argv[0]);
+  if( p && type!=SQLITE_NULL ){
+    p->cnt++;
+    if( type==SQLITE_INTEGER ){
+      i64 v = sqlite3_value_int64(argv[0]);
+      p->rSum += v;
+      if( (p->approx|p->overflow)==0 ){
+        i64 iNewSum = p->iSum + v;
+        int s1 = p->iSum >> (sizeof(i64)*8-1);
+        int s2 = v       >> (sizeof(i64)*8-1);
+        int s3 = iNewSum >> (sizeof(i64)*8-1);
+        p->overflow = (s1&s2&~s3) | (~s1&~s2&s3);
+        p->iSum = iNewSum;
+      }
+    }else{
+      p->rSum += sqlite3_value_double(argv[0]);
+      p->approx = 1;
+    }
+  }
+}
+static void sumFinalize(sqlite3_context *context){
+  SumCtx *p;
+  p = sqlite3_aggregate_context(context, 0);
+  if( p && p->cnt>0 ){
+    if( p->overflow ){
+      sqlite3_result_error(context,"integer overflow",-1);
+    }else if( p->approx ){
+      sqlite3_result_double(context, p->rSum);
+    }else{
+      sqlite3_result_int64(context, p->iSum);
+    }
+  }
+}
+static void avgFinalize(sqlite3_context *context){
+  SumCtx *p;
+  p = sqlite3_aggregate_context(context, 0);
+  if( p && p->cnt>0 ){
+    sqlite3_result_double(context, p->rSum/(double)p->cnt);
+  }
+}
+static void totalFinalize(sqlite3_context *context){
+  SumCtx *p;
+  p = sqlite3_aggregate_context(context, 0);
+  sqlite3_result_double(context, p ? p->rSum : 0.0);
+}
+
+/*
+** The following structure keeps track of state information for the
+** count() aggregate function.
+*/
+typedef struct CountCtx CountCtx;
+struct CountCtx {
+  i64 n;
+};
+
+/*
+** Routines to implement the count() aggregate function.
+*/
+static void countStep(sqlite3_context *context, int argc, sqlite3_value **argv){
+  CountCtx *p;
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0])) && p ){
+    p->n++;
+  }
+}   
+static void countFinalize(sqlite3_context *context){
+  CountCtx *p;
+  p = sqlite3_aggregate_context(context, 0);
+  sqlite3_result_int64(context, p ? p->n : 0);
+}
+
+/*
+** Routines to implement min() and max() aggregate functions.
+*/
+static void minmaxStep(sqlite3_context *context, int argc, sqlite3_value **argv){
+  Mem *pArg  = (Mem *)argv[0];
+  Mem *pBest;
+
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  pBest = (Mem *)sqlite3_aggregate_context(context, sizeof(*pBest));
+  if( !pBest ) return;
+
+  if( pBest->flags ){
+    int max;
+    int cmp;
+    CollSeq *pColl = sqlite3GetFuncCollSeq(context);
+    /* This step function is used for both the min() and max() aggregates,
+    ** the only difference between the two being that the sense of the
+    ** comparison is inverted. For the max() aggregate, the
+    ** sqlite3_user_data() function returns (void *)-1. For min() it
+    ** returns (void *)db, where db is the sqlite3* database pointer.
+    ** Therefore the next statement sets variable 'max' to 1 for the max()
+    ** aggregate, or 0 for min().
+    */
+    max = sqlite3_user_data(context)!=0;
+    cmp = sqlite3MemCompare(pBest, pArg, pColl);
+    if( (max && cmp<0) || (!max && cmp>0) ){
+      sqlite3VdbeMemCopy(pBest, pArg);
+    }
+  }else{
+    sqlite3VdbeMemCopy(pBest, pArg);
+  }
+}
+static void minMaxFinalize(sqlite3_context *context){
+  sqlite3_value *pRes;
+  pRes = (sqlite3_value *)sqlite3_aggregate_context(context, 0);
+  if( pRes ){
+    if( pRes->flags ){
+      sqlite3_result_value(context, pRes);
+    }
+    sqlite3VdbeMemRelease(pRes);
+  }
+}
+
+/*
+** group_concat(EXPR, ?SEPARATOR?)
+*/
+static void groupConcatStep(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const char *zVal;
+  StrAccum *pAccum;
+  const char *zSep;
+  int nVal, nSep, i;
+  if( argc==0 || sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  pAccum = (StrAccum*)sqlite3_aggregate_context(context, sizeof(*pAccum));
+
+  if( pAccum ){
+    sqlite3 *db = sqlite3_context_db_handle(context);
+    pAccum->useMalloc = 1;
+    pAccum->mxAlloc = db->aLimit[SQLITE_LIMIT_LENGTH];
+    if( pAccum->nChar ){
+      if( argc>1 ){
+        zSep = (char*)sqlite3_value_text(argv[argc-1]);
+        nSep = sqlite3_value_bytes(argv[argc-1]);
+      }else{
+        zSep = ",";
+        nSep = 1;
+      }
+      sqlite3StrAccumAppend(pAccum, zSep, nSep);
+    }
+    i = 0;
+    do{
+      zVal = (char*)sqlite3_value_text(argv[i]);
+      nVal = sqlite3_value_bytes(argv[i]);
+      sqlite3StrAccumAppend(pAccum, zVal, nVal);
+      i++;
+    }while( i<argc-1 );
+  }
+}
+static void groupConcatFinalize(sqlite3_context *context){
+  StrAccum *pAccum;
+  pAccum = sqlite3_aggregate_context(context, 0);
+  if( pAccum ){
+    if( pAccum->tooBig ){
+      sqlite3_result_error_toobig(context);
+    }else if( pAccum->mallocFailed ){
+      sqlite3_result_error_nomem(context);
+    }else{    
+      sqlite3_result_text(context, sqlite3StrAccumFinish(pAccum), -1, 
+                          sqlite3_free);
+    }
+  }
+}
+
+/*
+** This function registered all of the above C functions as SQL
+** functions.  This should be the only routine in this file with
+** external linkage.
+*/
+void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
+  static const struct {
+     char *zName;
+     signed char nArg;
+     u8 argType;           /* 1: 0, 2: 1, 3: 2,...  N:  N-1. */
+     u8 eTextRep;          /* 1: UTF-16.  0: UTF-8 */
+     u8 needCollSeq;
+     void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
+  } aFuncs[] = {
+    { "min",               -1, 0, SQLITE_UTF8,    1, minmaxFunc },
+    { "min",                0, 0, SQLITE_UTF8,    1, 0          },
+    { "max",               -1, 1, SQLITE_UTF8,    1, minmaxFunc },
+    { "max",                0, 1, SQLITE_UTF8,    1, 0          },
+    { "typeof",             1, 0, SQLITE_UTF8,    0, typeofFunc },
+    { "length",             1, 0, SQLITE_UTF8,    0, lengthFunc },
+    { "substr",             2, 0, SQLITE_UTF8,    0, substrFunc },
+    { "substr",             3, 0, SQLITE_UTF8,    0, substrFunc },
+    { "abs",                1, 0, SQLITE_UTF8,    0, absFunc    },
+    { "round",              1, 0, SQLITE_UTF8,    0, roundFunc  },
+    { "round",              2, 0, SQLITE_UTF8,    0, roundFunc  },
+    { "upper",              1, 0, SQLITE_UTF8,    0, upperFunc  },
+    { "lower",              1, 0, SQLITE_UTF8,    0, lowerFunc  },
+    { "coalesce",          -1, 0, SQLITE_UTF8,    0, ifnullFunc },
+    { "coalesce",           0, 0, SQLITE_UTF8,    0, 0          },
+    { "coalesce",           1, 0, SQLITE_UTF8,    0, 0          },
+    { "hex",                1, 0, SQLITE_UTF8,    0, hexFunc    },
+    { "ifnull",             2, 0, SQLITE_UTF8,    1, ifnullFunc },
+    { "random",            -1, 0, SQLITE_UTF8,    0, randomFunc },
+    { "randomblob",         1, 0, SQLITE_UTF8,    0, randomBlob },
+    { "nullif",             2, 0, SQLITE_UTF8,    1, nullifFunc },
+    { "sqlite_version",     0, 0, SQLITE_UTF8,    0, versionFunc},
+    { "quote",              1, 0, SQLITE_UTF8,    0, quoteFunc  },
+    { "last_insert_rowid",  0, 0, SQLITE_UTF8, 0, last_insert_rowid },
+    { "changes",            0, 0, SQLITE_UTF8, 0, changes           },
+    { "total_changes",      0, 0, SQLITE_UTF8, 0, total_changes     },
+    { "replace",            3, 0, SQLITE_UTF8,    0, replaceFunc       },
+    { "ltrim",              1, 1, SQLITE_UTF8,    0, trimFunc          },
+    { "ltrim",              2, 1, SQLITE_UTF8,    0, trimFunc          },
+    { "rtrim",              1, 2, SQLITE_UTF8,    0, trimFunc          },
+    { "rtrim",              2, 2, SQLITE_UTF8,    0, trimFunc          },
+    { "trim",               1, 3, SQLITE_UTF8,    0, trimFunc          },
+    { "trim",               2, 3, SQLITE_UTF8,    0, trimFunc          },
+    { "zeroblob",           1, 0, SQLITE_UTF8,    0, zeroblobFunc      },
+#ifdef SQLITE_SOUNDEX
+    { "soundex",            1, 0, SQLITE_UTF8,    0, soundexFunc},
+#endif
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+    { "load_extension",     1, 0, SQLITE_UTF8, 0, loadExt },
+    { "load_extension",     2, 0, SQLITE_UTF8, 0, loadExt },
+#endif
+  };
+  static const struct {
+    char *zName;
+    signed char nArg;
+    u8 argType;
+    u8 needCollSeq;
+    void (*xStep)(sqlite3_context*,int,sqlite3_value**);
+    void (*xFinalize)(sqlite3_context*);
+  } aAggs[] = {
+    { "min",    1, 0, 1, minmaxStep,   minMaxFinalize },
+    { "max",    1, 1, 1, minmaxStep,   minMaxFinalize },
+    { "sum",    1, 0, 0, sumStep,      sumFinalize    },
+    { "total",  1, 0, 0, sumStep,      totalFinalize    },
+    { "avg",    1, 0, 0, sumStep,      avgFinalize    },
+    { "count",  0, 0, 0, countStep,    countFinalize  },
+    { "count",  1, 0, 0, countStep,    countFinalize  },
+    { "group_concat", -1, 0, 0, groupConcatStep, groupConcatFinalize },
+  };
+  int i;
+
+  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
+    void *pArg;
+    u8 argType = aFuncs[i].argType;
+    pArg = SQLITE_INT_TO_PTR(argType);
+    sqlite3CreateFunc(db, aFuncs[i].zName, aFuncs[i].nArg,
+        aFuncs[i].eTextRep, pArg, aFuncs[i].xFunc, 0, 0);
+    if( aFuncs[i].needCollSeq ){
+      FuncDef *pFunc = sqlite3FindFunction(db, aFuncs[i].zName, 
+          strlen(aFuncs[i].zName), aFuncs[i].nArg, aFuncs[i].eTextRep, 0);
+      if( pFunc && aFuncs[i].needCollSeq ){
+        pFunc->needCollSeq = 1;
+      }
+    }
+  }
+#ifndef SQLITE_OMIT_ALTERTABLE
+  sqlite3AlterFunctions(db);
+#endif
+#ifndef SQLITE_OMIT_PARSER
+  sqlite3AttachFunctions(db);
+#endif
+  for(i=0; i<sizeof(aAggs)/sizeof(aAggs[0]); i++){
+    void *pArg = SQLITE_INT_TO_PTR(aAggs[i].argType);
+    sqlite3CreateFunc(db, aAggs[i].zName, aAggs[i].nArg, SQLITE_UTF8, 
+        pArg, 0, aAggs[i].xStep, aAggs[i].xFinalize);
+    if( aAggs[i].needCollSeq ){
+      FuncDef *pFunc = sqlite3FindFunction( db, aAggs[i].zName,
+          strlen(aAggs[i].zName), aAggs[i].nArg, SQLITE_UTF8, 0);
+      if( pFunc && aAggs[i].needCollSeq ){
+        pFunc->needCollSeq = 1;
+      }
+    }
+  }
+  sqlite3RegisterDateTimeFunctions(db);
+  if( !db->mallocFailed ){
+    int rc = sqlite3_overload_function(db, "MATCH", 2);
+    assert( rc==SQLITE_NOMEM || rc==SQLITE_OK );
+    if( rc==SQLITE_NOMEM ){
+      db->mallocFailed = 1;
+    }
+  }
+#ifdef SQLITE_SSE
+  (void)sqlite3SseFunctions(db);
+#endif
+#ifdef SQLITE_CASE_SENSITIVE_LIKE
+  sqlite3RegisterLikeFunctions(db, 1);
+#else
+  sqlite3RegisterLikeFunctions(db, 0);
+#endif
+}
+
+/*
+** Set the LIKEOPT flag on the 2-argument function with the given name.
+*/
+static void setLikeOptFlag(sqlite3 *db, const char *zName, int flagVal){
+  FuncDef *pDef;
+  pDef = sqlite3FindFunction(db, zName, strlen(zName), 2, SQLITE_UTF8, 0);
+  if( pDef ){
+    pDef->flags = flagVal;
+  }
+}
+
+/*
+** Register the built-in LIKE and GLOB functions.  The caseSensitive
+** parameter determines whether or not the LIKE operator is case
+** sensitive.  GLOB is always case sensitive.
+*/
+void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive){
+  struct compareInfo *pInfo;
+  if( caseSensitive ){
+    pInfo = (struct compareInfo*)&likeInfoAlt;
+  }else{
+    pInfo = (struct compareInfo*)&likeInfoNorm;
+  }
+  sqlite3CreateFunc(db, "like", 2, SQLITE_UTF8, pInfo, likeFunc, 0, 0);
+  sqlite3CreateFunc(db, "like", 3, SQLITE_UTF8, pInfo, likeFunc, 0, 0);
+  sqlite3CreateFunc(db, "glob", 2, SQLITE_UTF8, 
+      (struct compareInfo*)&globInfo, likeFunc, 0,0);
+  setLikeOptFlag(db, "glob", SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE);
+  setLikeOptFlag(db, "like", 
+      caseSensitive ? (SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE) : SQLITE_FUNC_LIKE);
+}
+
+/*
+** pExpr points to an expression which implements a function.  If
+** it is appropriate to apply the LIKE optimization to that function
+** then set aWc[0] through aWc[2] to the wildcard characters and
+** return TRUE.  If the function is not a LIKE-style function then
+** return FALSE.
+*/
+int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocase, char *aWc){
+  FuncDef *pDef;
+  if( pExpr->op!=TK_FUNCTION || !pExpr->pList ){
+    return 0;
+  }
+  if( pExpr->pList->nExpr!=2 ){
+    return 0;
+  }
+  pDef = sqlite3FindFunction(db, (char*)pExpr->token.z, pExpr->token.n, 2,
+                             SQLITE_UTF8, 0);
+  if( pDef==0 || (pDef->flags & SQLITE_FUNC_LIKE)==0 ){
+    return 0;
+  }
+
+  /* The memcpy() statement assumes that the wildcard characters are
+  ** the first three statements in the compareInfo structure.  The
+  ** asserts() that follow verify that assumption
+  */
+  memcpy(aWc, pDef->pUserData, 3);
+  assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );
+  assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
+  assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );
+  *pIsNocase = (pDef->flags & SQLITE_FUNC_CASE)==0;
+  return 1;
+}
diff --git a/third_party/sqlite/src/global.c b/third_party/sqlite/src/global.c
new file mode 100755
index 0000000..fa59d4a
--- /dev/null
+++ b/third_party/sqlite/src/global.c
@@ -0,0 +1,77 @@
+/*
+** 2008 June 13
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains definitions of global variables and contants.
+**
+** $Id: global.c,v 1.4 2008/07/28 19:34:53 drh Exp $
+*/
+#include "sqliteInt.h"
+
+
+/* An array to map all upper-case characters into their corresponding
+** lower-case character. 
+**
+** SQLite only considers US-ASCII (or EBCDIC) characters.  We do not
+** handle case conversions for the UTF character set since the tables
+** involved are nearly as big or bigger than SQLite itself.
+*/
+const unsigned char sqlite3UpperToLower[] = {
+#ifdef SQLITE_ASCII
+      0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17,
+     18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
+     36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
+     54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 97, 98, 99,100,101,102,103,
+    104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,
+    122, 91, 92, 93, 94, 95, 96, 97, 98, 99,100,101,102,103,104,105,106,107,
+    108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,
+    126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
+    144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,
+    162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,
+    180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,
+    198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,214,215,
+    216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231,232,233,
+    234,235,236,237,238,239,240,241,242,243,244,245,246,247,248,249,250,251,
+    252,253,254,255
+#endif
+#ifdef SQLITE_EBCDIC
+      0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, /* 0x */
+     16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, /* 1x */
+     32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, /* 2x */
+     48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, /* 3x */
+     64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, /* 4x */
+     80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, /* 5x */
+     96, 97, 66, 67, 68, 69, 70, 71, 72, 73,106,107,108,109,110,111, /* 6x */
+    112, 81, 82, 83, 84, 85, 86, 87, 88, 89,122,123,124,125,126,127, /* 7x */
+    128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143, /* 8x */
+    144,145,146,147,148,149,150,151,152,153,154,155,156,157,156,159, /* 9x */
+    160,161,162,163,164,165,166,167,168,169,170,171,140,141,142,175, /* Ax */
+    176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191, /* Bx */
+    192,129,130,131,132,133,134,135,136,137,202,203,204,205,206,207, /* Cx */
+    208,145,146,147,148,149,150,151,152,153,218,219,220,221,222,223, /* Dx */
+    224,225,162,163,164,165,166,167,168,169,232,203,204,205,206,207, /* Ex */
+    239,240,241,242,243,244,245,246,247,248,249,219,220,221,222,255, /* Fx */
+#endif
+};
+
+/*
+** The following singleton contains the global configuration for
+** the SQLite library.
+*/
+struct Sqlite3Config sqlite3Config = {
+   1,                /* bMemstat */
+   1,                /* bCoreMutex */
+   1,                /* bFullMutex */
+   0x7ffffffe,       /* mxStrlen */
+   100,              /* szLookaside */
+   500,              /* nLookaside */
+   /* Other fields all default to zero */
+};
diff --git a/third_party/sqlite/src/hash.c b/third_party/sqlite/src/hash.c
new file mode 100755
index 0000000..df73698
--- /dev/null
+++ b/third_party/sqlite/src/hash.c
@@ -0,0 +1,423 @@
+/*
+** 2001 September 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This is the implementation of generic hash-tables
+** used in SQLite.
+**
+** $Id: hash.c,v 1.30 2008/06/20 14:59:51 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+#include <assert.h>
+
+/* Turn bulk memory into a hash table object by initializing the
+** fields of the Hash structure.
+**
+** "pNew" is a pointer to the hash table that is to be initialized.
+** keyClass is one of the constants SQLITE_HASH_INT, SQLITE_HASH_POINTER,
+** SQLITE_HASH_BINARY, or SQLITE_HASH_STRING.  The value of keyClass 
+** determines what kind of key the hash table will use.  "copyKey" is
+** true if the hash table should make its own private copy of keys and
+** false if it should just use the supplied pointer.  CopyKey only makes
+** sense for SQLITE_HASH_STRING and SQLITE_HASH_BINARY and is ignored
+** for other key classes.
+*/
+void sqlite3HashInit(Hash *pNew, int keyClass, int copyKey){
+  assert( pNew!=0 );
+  assert( keyClass>=SQLITE_HASH_STRING && keyClass<=SQLITE_HASH_BINARY );
+  pNew->keyClass = keyClass;
+#if 0
+  if( keyClass==SQLITE_HASH_POINTER || keyClass==SQLITE_HASH_INT ) copyKey = 0;
+#endif
+  pNew->copyKey = copyKey;
+  pNew->first = 0;
+  pNew->count = 0;
+  pNew->htsize = 0;
+  pNew->ht = 0;
+}
+
+/* Remove all entries from a hash table.  Reclaim all memory.
+** Call this routine to delete a hash table or to reset a hash table
+** to the empty state.
+*/
+void sqlite3HashClear(Hash *pH){
+  HashElem *elem;         /* For looping over all elements of the table */
+
+  assert( pH!=0 );
+  elem = pH->first;
+  pH->first = 0;
+  sqlite3_free(pH->ht);
+  pH->ht = 0;
+  pH->htsize = 0;
+  while( elem ){
+    HashElem *next_elem = elem->next;
+    if( pH->copyKey && elem->pKey ){
+      sqlite3_free(elem->pKey);
+    }
+    sqlite3_free(elem);
+    elem = next_elem;
+  }
+  pH->count = 0;
+}
+
+#if 0 /* NOT USED */
+/*
+** Hash and comparison functions when the mode is SQLITE_HASH_INT
+*/
+static int intHash(const void *pKey, int nKey){
+  return nKey ^ (nKey<<8) ^ (nKey>>8);
+}
+static int intCompare(const void *pKey1, int n1, const void *pKey2, int n2){
+  return n2 - n1;
+}
+#endif
+
+#if 0 /* NOT USED */
+/*
+** Hash and comparison functions when the mode is SQLITE_HASH_POINTER
+*/
+static int ptrHash(const void *pKey, int nKey){
+  uptr x = Addr(pKey);
+  return x ^ (x<<8) ^ (x>>8);
+}
+static int ptrCompare(const void *pKey1, int n1, const void *pKey2, int n2){
+  if( pKey1==pKey2 ) return 0;
+  if( pKey1<pKey2 ) return -1;
+  return 1;
+}
+#endif
+
+/*
+** Hash and comparison functions when the mode is SQLITE_HASH_STRING
+*/
+static int strHash(const void *pKey, int nKey){
+  const char *z = (const char *)pKey;
+  int h = 0;
+  if( nKey<=0 ) nKey = strlen(z);
+  while( nKey > 0  ){
+    h = (h<<3) ^ h ^ sqlite3UpperToLower[(unsigned char)*z++];
+    nKey--;
+  }
+  return h & 0x7fffffff;
+}
+static int strCompare(const void *pKey1, int n1, const void *pKey2, int n2){
+  if( n1!=n2 ) return 1;
+  return sqlite3StrNICmp((const char*)pKey1,(const char*)pKey2,n1);
+}
+
+/*
+** Hash and comparison functions when the mode is SQLITE_HASH_BINARY
+*/
+static int binHash(const void *pKey, int nKey){
+  int h = 0;
+  const char *z = (const char *)pKey;
+  while( nKey-- > 0 ){
+    h = (h<<3) ^ h ^ *(z++);
+  }
+  return h & 0x7fffffff;
+}
+static int binCompare(const void *pKey1, int n1, const void *pKey2, int n2){
+  if( n1!=n2 ) return 1;
+  return memcmp(pKey1,pKey2,n1);
+}
+
+/*
+** Return a pointer to the appropriate hash function given the key class.
+**
+** The C syntax in this function definition may be unfamilar to some 
+** programmers, so we provide the following additional explanation:
+**
+** The name of the function is "hashFunction".  The function takes a
+** single parameter "keyClass".  The return value of hashFunction()
+** is a pointer to another function.  Specifically, the return value
+** of hashFunction() is a pointer to a function that takes two parameters
+** with types "const void*" and "int" and returns an "int".
+*/
+static int (*hashFunction(int keyClass))(const void*,int){
+#if 0  /* HASH_INT and HASH_POINTER are never used */
+  switch( keyClass ){
+    case SQLITE_HASH_INT:     return &intHash;
+    case SQLITE_HASH_POINTER: return &ptrHash;
+    case SQLITE_HASH_STRING:  return &strHash;
+    case SQLITE_HASH_BINARY:  return &binHash;;
+    default: break;
+  }
+  return 0;
+#else
+  if( keyClass==SQLITE_HASH_STRING ){
+    return &strHash;
+  }else{
+    assert( keyClass==SQLITE_HASH_BINARY );
+    return &binHash;
+  }
+#endif
+}
+
+/*
+** Return a pointer to the appropriate hash function given the key class.
+**
+** For help in interpreted the obscure C code in the function definition,
+** see the header comment on the previous function.
+*/
+static int (*compareFunction(int keyClass))(const void*,int,const void*,int){
+#if 0 /* HASH_INT and HASH_POINTER are never used */
+  switch( keyClass ){
+    case SQLITE_HASH_INT:     return &intCompare;
+    case SQLITE_HASH_POINTER: return &ptrCompare;
+    case SQLITE_HASH_STRING:  return &strCompare;
+    case SQLITE_HASH_BINARY:  return &binCompare;
+    default: break;
+  }
+  return 0;
+#else
+  if( keyClass==SQLITE_HASH_STRING ){
+    return &strCompare;
+  }else{
+    assert( keyClass==SQLITE_HASH_BINARY );
+    return &binCompare;
+  }
+#endif
+}
+
+/* Link an element into the hash table
+*/
+static void insertElement(
+  Hash *pH,              /* The complete hash table */
+  struct _ht *pEntry,    /* The entry into which pNew is inserted */
+  HashElem *pNew         /* The element to be inserted */
+){
+  HashElem *pHead;       /* First element already in pEntry */
+  pHead = pEntry->chain;
+  if( pHead ){
+    pNew->next = pHead;
+    pNew->prev = pHead->prev;
+    if( pHead->prev ){ pHead->prev->next = pNew; }
+    else             { pH->first = pNew; }
+    pHead->prev = pNew;
+  }else{
+    pNew->next = pH->first;
+    if( pH->first ){ pH->first->prev = pNew; }
+    pNew->prev = 0;
+    pH->first = pNew;
+  }
+  pEntry->count++;
+  pEntry->chain = pNew;
+}
+
+
+/* Resize the hash table so that it cantains "new_size" buckets.
+** "new_size" must be a power of 2.  The hash table might fail 
+** to resize if sqlite3_malloc() fails.
+*/
+static void rehash(Hash *pH, int new_size){
+  struct _ht *new_ht;            /* The new hash table */
+  HashElem *elem, *next_elem;    /* For looping over existing elements */
+  int (*xHash)(const void*,int); /* The hash function */
+
+#ifdef SQLITE_MALLOC_SOFT_LIMIT
+  if( new_size*sizeof(struct _ht)>SQLITE_MALLOC_SOFT_LIMIT ){
+    new_size = SQLITE_MALLOC_SOFT_LIMIT/sizeof(struct _ht);
+  }
+  if( new_size==pH->htsize ) return;
+#endif
+
+  /* There is a call to sqlite3_malloc() inside rehash(). If there is
+  ** already an allocation at pH->ht, then if this malloc() fails it
+  ** is benign (since failing to resize a hash table is a performance
+  ** hit only, not a fatal error).
+  */
+  if( pH->htsize>0 ) sqlite3BeginBenignMalloc();
+  new_ht = (struct _ht *)sqlite3MallocZero( new_size*sizeof(struct _ht) );
+  if( pH->htsize>0 ) sqlite3EndBenignMalloc();
+
+  if( new_ht==0 ) return;
+  sqlite3_free(pH->ht);
+  pH->ht = new_ht;
+  pH->htsize = new_size;
+  xHash = hashFunction(pH->keyClass);
+  for(elem=pH->first, pH->first=0; elem; elem = next_elem){
+    int h = (*xHash)(elem->pKey, elem->nKey) & (new_size-1);
+    next_elem = elem->next;
+    insertElement(pH, &new_ht[h], elem);
+  }
+}
+
+/* This function (for internal use only) locates an element in an
+** hash table that matches the given key.  The hash for this key has
+** already been computed and is passed as the 4th parameter.
+*/
+static HashElem *findElementGivenHash(
+  const Hash *pH,     /* The pH to be searched */
+  const void *pKey,   /* The key we are searching for */
+  int nKey,
+  int h               /* The hash for this key. */
+){
+  HashElem *elem;                /* Used to loop thru the element list */
+  int count;                     /* Number of elements left to test */
+  int (*xCompare)(const void*,int,const void*,int);  /* comparison function */
+
+  if( pH->ht ){
+    struct _ht *pEntry = &pH->ht[h];
+    elem = pEntry->chain;
+    count = pEntry->count;
+    xCompare = compareFunction(pH->keyClass);
+    while( count-- && elem ){
+      if( (*xCompare)(elem->pKey,elem->nKey,pKey,nKey)==0 ){ 
+        return elem;
+      }
+      elem = elem->next;
+    }
+  }
+  return 0;
+}
+
+/* Remove a single entry from the hash table given a pointer to that
+** element and a hash on the element's key.
+*/
+static void removeElementGivenHash(
+  Hash *pH,         /* The pH containing "elem" */
+  HashElem* elem,   /* The element to be removed from the pH */
+  int h             /* Hash value for the element */
+){
+  struct _ht *pEntry;
+  if( elem->prev ){
+    elem->prev->next = elem->next; 
+  }else{
+    pH->first = elem->next;
+  }
+  if( elem->next ){
+    elem->next->prev = elem->prev;
+  }
+  pEntry = &pH->ht[h];
+  if( pEntry->chain==elem ){
+    pEntry->chain = elem->next;
+  }
+  pEntry->count--;
+  if( pEntry->count<=0 ){
+    pEntry->chain = 0;
+  }
+  if( pH->copyKey ){
+    sqlite3_free(elem->pKey);
+  }
+  sqlite3_free( elem );
+  pH->count--;
+  if( pH->count<=0 ){
+    assert( pH->first==0 );
+    assert( pH->count==0 );
+    sqlite3HashClear(pH);
+  }
+}
+
+/* Attempt to locate an element of the hash table pH with a key
+** that matches pKey,nKey.  Return a pointer to the corresponding 
+** HashElem structure for this element if it is found, or NULL
+** otherwise.
+*/
+HashElem *sqlite3HashFindElem(const Hash *pH, const void *pKey, int nKey){
+  int h;             /* A hash on key */
+  HashElem *elem;    /* The element that matches key */
+  int (*xHash)(const void*,int);  /* The hash function */
+
+  if( pH==0 || pH->ht==0 ) return 0;
+  xHash = hashFunction(pH->keyClass);
+  assert( xHash!=0 );
+  h = (*xHash)(pKey,nKey);
+  elem = findElementGivenHash(pH,pKey,nKey, h % pH->htsize);
+  return elem;
+}
+
+/* Attempt to locate an element of the hash table pH with a key
+** that matches pKey,nKey.  Return the data for this element if it is
+** found, or NULL if there is no match.
+*/
+void *sqlite3HashFind(const Hash *pH, const void *pKey, int nKey){
+  HashElem *elem;    /* The element that matches key */
+  elem = sqlite3HashFindElem(pH, pKey, nKey);
+  return elem ? elem->data : 0;
+}
+
+/* Insert an element into the hash table pH.  The key is pKey,nKey
+** and the data is "data".
+**
+** If no element exists with a matching key, then a new
+** element is created.  A copy of the key is made if the copyKey
+** flag is set.  NULL is returned.
+**
+** If another element already exists with the same key, then the
+** new data replaces the old data and the old data is returned.
+** The key is not copied in this instance.  If a malloc fails, then
+** the new data is returned and the hash table is unchanged.
+**
+** If the "data" parameter to this function is NULL, then the
+** element corresponding to "key" is removed from the hash table.
+*/
+void *sqlite3HashInsert(Hash *pH, const void *pKey, int nKey, void *data){
+  int hraw;             /* Raw hash value of the key */
+  int h;                /* the hash of the key modulo hash table size */
+  HashElem *elem;       /* Used to loop thru the element list */
+  HashElem *new_elem;   /* New element added to the pH */
+  int (*xHash)(const void*,int);  /* The hash function */
+
+  assert( pH!=0 );
+  xHash = hashFunction(pH->keyClass);
+  assert( xHash!=0 );
+  hraw = (*xHash)(pKey, nKey);
+  if( pH->htsize ){
+    h = hraw % pH->htsize;
+    elem = findElementGivenHash(pH,pKey,nKey,h);
+    if( elem ){
+      void *old_data = elem->data;
+      if( data==0 ){
+        removeElementGivenHash(pH,elem,h);
+      }else{
+        elem->data = data;
+        if( !pH->copyKey ){
+          elem->pKey = (void *)pKey;
+        }
+        assert(nKey==elem->nKey);
+      }
+      return old_data;
+    }
+  }
+  if( data==0 ) return 0;
+  new_elem = (HashElem*)sqlite3Malloc( sizeof(HashElem) );
+  if( new_elem==0 ) return data;
+  if( pH->copyKey && pKey!=0 ){
+    new_elem->pKey = sqlite3Malloc( nKey );
+    if( new_elem->pKey==0 ){
+      sqlite3_free(new_elem);
+      return data;
+    }
+    memcpy((void*)new_elem->pKey, pKey, nKey);
+  }else{
+    new_elem->pKey = (void*)pKey;
+  }
+  new_elem->nKey = nKey;
+  pH->count++;
+  if( pH->htsize==0 ){
+    rehash(pH, 128/sizeof(pH->ht[0]));
+    if( pH->htsize==0 ){
+      pH->count = 0;
+      if( pH->copyKey ){
+        sqlite3_free(new_elem->pKey);
+      }
+      sqlite3_free(new_elem);
+      return data;
+    }
+  }
+  if( pH->count > pH->htsize ){
+    rehash(pH,pH->htsize*2);
+  }
+  assert( pH->htsize>0 );
+  h = hraw % pH->htsize;
+  insertElement(pH, &pH->ht[h], new_elem);
+  new_elem->data = data;
+  return 0;
+}
diff --git a/third_party/sqlite/src/hash.h b/third_party/sqlite/src/hash.h
new file mode 100755
index 0000000..e3274e9
--- /dev/null
+++ b/third_party/sqlite/src/hash.h
@@ -0,0 +1,110 @@
+/*
+** 2001 September 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This is the header file for the generic hash-table implemenation
+** used in SQLite.
+**
+** $Id: hash.h,v 1.11 2007/09/04 14:31:47 danielk1977 Exp $
+*/
+#ifndef _SQLITE_HASH_H_
+#define _SQLITE_HASH_H_
+
+/* Forward declarations of structures. */
+typedef struct Hash Hash;
+typedef struct HashElem HashElem;
+
+/* A complete hash table is an instance of the following structure.
+** The internals of this structure are intended to be opaque -- client
+** code should not attempt to access or modify the fields of this structure
+** directly.  Change this structure only by using the routines below.
+** However, many of the "procedures" and "functions" for modifying and
+** accessing this structure are really macros, so we can't really make
+** this structure opaque.
+*/
+struct Hash {
+  char keyClass;          /* SQLITE_HASH_INT, _POINTER, _STRING, _BINARY */
+  char copyKey;           /* True if copy of key made on insert */
+  int count;              /* Number of entries in this table */
+  int htsize;             /* Number of buckets in the hash table */
+  HashElem *first;        /* The first element of the array */
+  struct _ht {            /* the hash table */
+    int count;               /* Number of entries with this hash */
+    HashElem *chain;         /* Pointer to first entry with this hash */
+  } *ht;
+};
+
+/* Each element in the hash table is an instance of the following 
+** structure.  All elements are stored on a single doubly-linked list.
+**
+** Again, this structure is intended to be opaque, but it can't really
+** be opaque because it is used by macros.
+*/
+struct HashElem {
+  HashElem *next, *prev;   /* Next and previous elements in the table */
+  void *data;              /* Data associated with this element */
+  void *pKey; int nKey;    /* Key associated with this element */
+};
+
+/*
+** There are 4 different modes of operation for a hash table:
+**
+**   SQLITE_HASH_INT         nKey is used as the key and pKey is ignored.
+**
+**   SQLITE_HASH_POINTER     pKey is used as the key and nKey is ignored.
+**
+**   SQLITE_HASH_STRING      pKey points to a string that is nKey bytes long
+**                           (including the null-terminator, if any).  Case
+**                           is ignored in comparisons.
+**
+**   SQLITE_HASH_BINARY      pKey points to binary data nKey bytes long. 
+**                           memcmp() is used to compare keys.
+**
+** A copy of the key is made for SQLITE_HASH_STRING and SQLITE_HASH_BINARY
+** if the copyKey parameter to HashInit is 1.  
+*/
+/* #define SQLITE_HASH_INT       1 // NOT USED */
+/* #define SQLITE_HASH_POINTER   2 // NOT USED */
+#define SQLITE_HASH_STRING    3
+#define SQLITE_HASH_BINARY    4
+
+/*
+** Access routines.  To delete, insert a NULL pointer.
+*/
+void sqlite3HashInit(Hash*, int keytype, int copyKey);
+void *sqlite3HashInsert(Hash*, const void *pKey, int nKey, void *pData);
+void *sqlite3HashFind(const Hash*, const void *pKey, int nKey);
+HashElem *sqlite3HashFindElem(const Hash*, const void *pKey, int nKey);
+void sqlite3HashClear(Hash*);
+
+/*
+** Macros for looping over all elements of a hash table.  The idiom is
+** like this:
+**
+**   Hash h;
+**   HashElem *p;
+**   ...
+**   for(p=sqliteHashFirst(&h); p; p=sqliteHashNext(p)){
+**     SomeStructure *pData = sqliteHashData(p);
+**     // do something with pData
+**   }
+*/
+#define sqliteHashFirst(H)  ((H)->first)
+#define sqliteHashNext(E)   ((E)->next)
+#define sqliteHashData(E)   ((E)->data)
+#define sqliteHashKey(E)    ((E)->pKey)
+#define sqliteHashKeysize(E) ((E)->nKey)
+
+/*
+** Number of entries in a hash table
+*/
+#define sqliteHashCount(H)  ((H)->count)
+
+#endif /* _SQLITE_HASH_H_ */
diff --git a/third_party/sqlite/src/hwtime.h b/third_party/sqlite/src/hwtime.h
new file mode 100755
index 0000000..896041e
--- /dev/null
+++ b/third_party/sqlite/src/hwtime.h
@@ -0,0 +1,87 @@
+/*
+** 2008 May 27
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains inline asm code for retrieving "high-performance"
+** counters for x86 class CPUs.
+**
+** $Id: hwtime.h,v 1.3 2008/08/01 14:33:15 shane Exp $
+*/
+#ifndef _HWTIME_H_
+#define _HWTIME_H_
+
+/*
+** The following routine only works on pentium-class (or newer) processors.
+** It uses the RDTSC opcode to read the cycle count value out of the
+** processor and returns that value.  This can be used for high-res
+** profiling.
+*/
+#if (defined(__GNUC__) || defined(_MSC_VER)) && \
+      (defined(i386) || defined(__i386__) || defined(_M_IX86))
+
+  #if defined(__GNUC__)
+
+  __inline__ sqlite_uint64 sqlite3Hwtime(void){
+     unsigned int lo, hi;
+     __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
+     return (sqlite_uint64)hi << 32 | lo;
+  }
+
+  #elif defined(_MSC_VER)
+
+  __declspec(naked) __inline sqlite_uint64 __cdecl sqlite3Hwtime(void){
+     __asm {
+        rdtsc
+        ret       ; return value at EDX:EAX
+     }
+  }
+
+  #endif
+
+#elif (defined(__GNUC__) && defined(__x86_64__))
+
+  __inline__ sqlite_uint64 sqlite3Hwtime(void){
+      unsigned long val;
+      __asm__ __volatile__ ("rdtsc" : "=A" (val));
+      return val;
+  }
+ 
+#elif (defined(__GNUC__) && defined(__ppc__))
+
+  __inline__ sqlite_uint64 sqlite3Hwtime(void){
+      unsigned long long retval;
+      unsigned long junk;
+      __asm__ __volatile__ ("\n\
+          1:      mftbu   %1\n\
+                  mftb    %L0\n\
+                  mftbu   %0\n\
+                  cmpw    %0,%1\n\
+                  bne     1b"
+                  : "=r" (retval), "=r" (junk));
+      return retval;
+  }
+
+#else
+
+  #error Need implementation of sqlite3Hwtime() for your platform.
+
+  /*
+  ** To compile without implementing sqlite3Hwtime() for your platform,
+  ** you can remove the above #error and use the following
+  ** stub function.  You will lose timing support for many
+  ** of the debugging and testing utilities, but it should at
+  ** least compile and run.
+  */
+  sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
+
+#endif
+
+#endif /* !defined(_HWTIME_H_) */
diff --git a/third_party/sqlite/src/insert.c b/third_party/sqlite/src/insert.c
new file mode 100755
index 0000000..9a3d46f
--- /dev/null
+++ b/third_party/sqlite/src/insert.c
@@ -0,0 +1,1738 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains C code routines that are called by the parser
+** to handle INSERT statements in SQLite.
+**
+** $Id: insert.c,v 1.248 2008/07/28 19:34:53 drh Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** Set P4 of the most recently inserted opcode to a column affinity
+** string for index pIdx. A column affinity string has one character
+** for each column in the table, according to the affinity of the column:
+**
+**  Character      Column affinity
+**  ------------------------------
+**  'a'            TEXT
+**  'b'            NONE
+**  'c'            NUMERIC
+**  'd'            INTEGER
+**  'e'            REAL
+**
+** An extra 'b' is appended to the end of the string to cover the
+** rowid that appears as the last column in every index.
+*/
+void sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){
+  if( !pIdx->zColAff ){
+    /* The first time a column affinity string for a particular index is
+    ** required, it is allocated and populated here. It is then stored as
+    ** a member of the Index structure for subsequent use.
+    **
+    ** The column affinity string will eventually be deleted by
+    ** sqliteDeleteIndex() when the Index structure itself is cleaned
+    ** up.
+    */
+    int n;
+    Table *pTab = pIdx->pTable;
+    sqlite3 *db = sqlite3VdbeDb(v);
+    pIdx->zColAff = (char *)sqlite3Malloc(pIdx->nColumn+2);
+    if( !pIdx->zColAff ){
+      db->mallocFailed = 1;
+      return;
+    }
+    for(n=0; n<pIdx->nColumn; n++){
+      pIdx->zColAff[n] = pTab->aCol[pIdx->aiColumn[n]].affinity;
+    }
+    pIdx->zColAff[n++] = SQLITE_AFF_NONE;
+    pIdx->zColAff[n] = 0;
+  }
+ 
+  sqlite3VdbeChangeP4(v, -1, pIdx->zColAff, 0);
+}
+
+/*
+** Set P4 of the most recently inserted opcode to a column affinity
+** string for table pTab. A column affinity string has one character
+** for each column indexed by the index, according to the affinity of the
+** column:
+**
+**  Character      Column affinity
+**  ------------------------------
+**  'a'            TEXT
+**  'b'            NONE
+**  'c'            NUMERIC
+**  'd'            INTEGER
+**  'e'            REAL
+*/
+void sqlite3TableAffinityStr(Vdbe *v, Table *pTab){
+  /* The first time a column affinity string for a particular table
+  ** is required, it is allocated and populated here. It is then 
+  ** stored as a member of the Table structure for subsequent use.
+  **
+  ** The column affinity string will eventually be deleted by
+  ** sqlite3DeleteTable() when the Table structure itself is cleaned up.
+  */
+  if( !pTab->zColAff ){
+    char *zColAff;
+    int i;
+    sqlite3 *db = sqlite3VdbeDb(v);
+
+    zColAff = (char *)sqlite3Malloc(pTab->nCol+1);
+    if( !zColAff ){
+      db->mallocFailed = 1;
+      return;
+    }
+
+    for(i=0; i<pTab->nCol; i++){
+      zColAff[i] = pTab->aCol[i].affinity;
+    }
+    zColAff[pTab->nCol] = '\0';
+
+    pTab->zColAff = zColAff;
+  }
+
+  sqlite3VdbeChangeP4(v, -1, pTab->zColAff, 0);
+}
+
+/*
+** Return non-zero if the table pTab in database iDb or any of its indices
+** have been opened at any point in the VDBE program beginning at location
+** iStartAddr throught the end of the program.  This is used to see if 
+** a statement of the form  "INSERT INTO <iDb, pTab> SELECT ..." can 
+** run without using temporary table for the results of the SELECT. 
+*/
+static int readsTable(Vdbe *v, int iStartAddr, int iDb, Table *pTab){
+  int i;
+  int iEnd = sqlite3VdbeCurrentAddr(v);
+  for(i=iStartAddr; i<iEnd; i++){
+    VdbeOp *pOp = sqlite3VdbeGetOp(v, i);
+    assert( pOp!=0 );
+    if( pOp->opcode==OP_OpenRead && pOp->p3==iDb ){
+      Index *pIndex;
+      int tnum = pOp->p2;
+      if( tnum==pTab->tnum ){
+        return 1;
+      }
+      for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
+        if( tnum==pIndex->tnum ){
+          return 1;
+        }
+      }
+    }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( pOp->opcode==OP_VOpen && pOp->p4.pVtab==pTab->pVtab ){
+      assert( pOp->p4.pVtab!=0 );
+      assert( pOp->p4type==P4_VTAB );
+      return 1;
+    }
+#endif
+  }
+  return 0;
+}
+
+#ifndef SQLITE_OMIT_AUTOINCREMENT
+/*
+** Write out code to initialize the autoincrement logic.  This code
+** looks up the current autoincrement value in the sqlite_sequence
+** table and stores that value in a register.  Code generated by
+** autoIncStep() will keep that register holding the largest
+** rowid value.  Code generated by autoIncEnd() will write the new
+** largest value of the counter back into the sqlite_sequence table.
+**
+** This routine returns the index of the mem[] cell that contains
+** the maximum rowid counter.
+**
+** Three consecutive registers are allocated by this routine.  The
+** first two hold the name of the target table and the maximum rowid 
+** inserted into the target table, respectively.
+** The third holds the rowid in sqlite_sequence where we will
+** write back the revised maximum rowid.  This routine returns the
+** index of the second of these three registers.
+*/
+static int autoIncBegin(
+  Parse *pParse,      /* Parsing context */
+  int iDb,            /* Index of the database holding pTab */
+  Table *pTab         /* The table we are writing to */
+){
+  int memId = 0;      /* Register holding maximum rowid */
+  if( pTab->autoInc ){
+    Vdbe *v = pParse->pVdbe;
+    Db *pDb = &pParse->db->aDb[iDb];
+    int iCur = pParse->nTab;
+    int addr;               /* Address of the top of the loop */
+    assert( v );
+    pParse->nMem++;         /* Holds name of table */
+    memId = ++pParse->nMem;
+    pParse->nMem++;
+    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
+    addr = sqlite3VdbeCurrentAddr(v);
+    sqlite3VdbeAddOp4(v, OP_String8, 0, memId-1, 0, pTab->zName, 0);
+    sqlite3VdbeAddOp2(v, OP_Rewind, iCur, addr+9);
+    sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, memId);
+    sqlite3VdbeAddOp3(v, OP_Ne, memId-1, addr+7, memId);
+    sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
+    sqlite3VdbeAddOp2(v, OP_Rowid, iCur, memId+1);
+    sqlite3VdbeAddOp3(v, OP_Column, iCur, 1, memId);
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, addr+9);
+    sqlite3VdbeAddOp2(v, OP_Next, iCur, addr+2);
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, memId);
+    sqlite3VdbeAddOp2(v, OP_Close, iCur, 0);
+  }
+  return memId;
+}
+
+/*
+** Update the maximum rowid for an autoincrement calculation.
+**
+** This routine should be called when the top of the stack holds a
+** new rowid that is about to be inserted.  If that new rowid is
+** larger than the maximum rowid in the memId memory cell, then the
+** memory cell is updated.  The stack is unchanged.
+*/
+static void autoIncStep(Parse *pParse, int memId, int regRowid){
+  if( memId>0 ){
+    sqlite3VdbeAddOp2(pParse->pVdbe, OP_MemMax, memId, regRowid);
+  }
+}
+
+/*
+** After doing one or more inserts, the maximum rowid is stored
+** in reg[memId].  Generate code to write this value back into the
+** the sqlite_sequence table.
+*/
+static void autoIncEnd(
+  Parse *pParse,     /* The parsing context */
+  int iDb,           /* Index of the database holding pTab */
+  Table *pTab,       /* Table we are inserting into */
+  int memId          /* Memory cell holding the maximum rowid */
+){
+  if( pTab->autoInc ){
+    int iCur = pParse->nTab;
+    Vdbe *v = pParse->pVdbe;
+    Db *pDb = &pParse->db->aDb[iDb];
+    int j1;
+    int iRec = ++pParse->nMem;    /* Memory cell used for record */
+
+    assert( v );
+    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
+    j1 = sqlite3VdbeAddOp1(v, OP_NotNull, memId+1);
+    sqlite3VdbeAddOp2(v, OP_NewRowid, iCur, memId+1);
+    sqlite3VdbeJumpHere(v, j1);
+    sqlite3VdbeAddOp3(v, OP_MakeRecord, memId-1, 2, iRec);
+    sqlite3VdbeAddOp3(v, OP_Insert, iCur, iRec, memId+1);
+    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
+    sqlite3VdbeAddOp1(v, OP_Close, iCur);
+  }
+}
+#else
+/*
+** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
+** above are all no-ops
+*/
+# define autoIncBegin(A,B,C) (0)
+# define autoIncStep(A,B,C)
+# define autoIncEnd(A,B,C,D)
+#endif /* SQLITE_OMIT_AUTOINCREMENT */
+
+
+/* Forward declaration */
+static int xferOptimization(
+  Parse *pParse,        /* Parser context */
+  Table *pDest,         /* The table we are inserting into */
+  Select *pSelect,      /* A SELECT statement to use as the data source */
+  int onError,          /* How to handle constraint errors */
+  int iDbDest           /* The database of pDest */
+);
+
+/*
+** This routine is call to handle SQL of the following forms:
+**
+**    insert into TABLE (IDLIST) values(EXPRLIST)
+**    insert into TABLE (IDLIST) select
+**
+** The IDLIST following the table name is always optional.  If omitted,
+** then a list of all columns for the table is substituted.  The IDLIST
+** appears in the pColumn parameter.  pColumn is NULL if IDLIST is omitted.
+**
+** The pList parameter holds EXPRLIST in the first form of the INSERT
+** statement above, and pSelect is NULL.  For the second form, pList is
+** NULL and pSelect is a pointer to the select statement used to generate
+** data for the insert.
+**
+** The code generated follows one of four templates.  For a simple
+** select with data coming from a VALUES clause, the code executes
+** once straight down through.  Pseudo-code follows (we call this
+** the "1st template"):
+**
+**         open write cursor to <table> and its indices
+**         puts VALUES clause expressions onto the stack
+**         write the resulting record into <table>
+**         cleanup
+**
+** The three remaining templates assume the statement is of the form
+**
+**   INSERT INTO <table> SELECT ...
+**
+** If the SELECT clause is of the restricted form "SELECT * FROM <table2>" -
+** in other words if the SELECT pulls all columns from a single table
+** and there is no WHERE or LIMIT or GROUP BY or ORDER BY clauses, and
+** if <table2> and <table1> are distinct tables but have identical
+** schemas, including all the same indices, then a special optimization
+** is invoked that copies raw records from <table2> over to <table1>.
+** See the xferOptimization() function for the implementation of this
+** template.  This is the 2nd template.
+**
+**         open a write cursor to <table>
+**         open read cursor on <table2>
+**         transfer all records in <table2> over to <table>
+**         close cursors
+**         foreach index on <table>
+**           open a write cursor on the <table> index
+**           open a read cursor on the corresponding <table2> index
+**           transfer all records from the read to the write cursors
+**           close cursors
+**         end foreach
+**
+** The 3rd template is for when the second template does not apply
+** and the SELECT clause does not read from <table> at any time.
+** The generated code follows this template:
+**
+**         EOF <- 0
+**         X <- A
+**         goto B
+**      A: setup for the SELECT
+**         loop over the rows in the SELECT
+**           load values into registers R..R+n
+**           yield X
+**         end loop
+**         cleanup after the SELECT
+**         EOF <- 1
+**         yield X
+**         goto A
+**      B: open write cursor to <table> and its indices
+**      C: yield X
+**         if EOF goto D
+**         insert the select result into <table> from R..R+n
+**         goto C
+**      D: cleanup
+**
+** The 4th template is used if the insert statement takes its
+** values from a SELECT but the data is being inserted into a table
+** that is also read as part of the SELECT.  In the third form,
+** we have to use a intermediate table to store the results of
+** the select.  The template is like this:
+**
+**         EOF <- 0
+**         X <- A
+**         goto B
+**      A: setup for the SELECT
+**         loop over the tables in the SELECT
+**           load value into register R..R+n
+**           yield X
+**         end loop
+**         cleanup after the SELECT
+**         EOF <- 1
+**         yield X
+**         halt-error
+**      B: open temp table
+**      L: yield X
+**         if EOF goto M
+**         insert row from R..R+n into temp table
+**         goto L
+**      M: open write cursor to <table> and its indices
+**         rewind temp table
+**      C: loop over rows of intermediate table
+**           transfer values form intermediate table into <table>
+**         end loop
+**      D: cleanup
+*/
+void sqlite3Insert(
+  Parse *pParse,        /* Parser context */
+  SrcList *pTabList,    /* Name of table into which we are inserting */
+  ExprList *pList,      /* List of values to be inserted */
+  Select *pSelect,      /* A SELECT statement to use as the data source */
+  IdList *pColumn,      /* Column names corresponding to IDLIST. */
+  int onError           /* How to handle constraint errors */
+){
+  sqlite3 *db;          /* The main database structure */
+  Table *pTab;          /* The table to insert into.  aka TABLE */
+  char *zTab;           /* Name of the table into which we are inserting */
+  const char *zDb;      /* Name of the database holding this table */
+  int i, j, idx;        /* Loop counters */
+  Vdbe *v;              /* Generate code into this virtual machine */
+  Index *pIdx;          /* For looping over indices of the table */
+  int nColumn;          /* Number of columns in the data */
+  int nHidden = 0;      /* Number of hidden columns if TABLE is virtual */
+  int baseCur = 0;      /* VDBE Cursor number for pTab */
+  int keyColumn = -1;   /* Column that is the INTEGER PRIMARY KEY */
+  int endOfLoop;        /* Label for the end of the insertion loop */
+  int useTempTable = 0; /* Store SELECT results in intermediate table */
+  int srcTab = 0;       /* Data comes from this temporary cursor if >=0 */
+  int addrInsTop = 0;   /* Jump to label "D" */
+  int addrCont = 0;     /* Top of insert loop. Label "C" in templates 3 and 4 */
+  int addrSelect = 0;   /* Address of coroutine that implements the SELECT */
+  SelectDest dest;      /* Destination for SELECT on rhs of INSERT */
+  int newIdx = -1;      /* Cursor for the NEW pseudo-table */
+  int iDb;              /* Index of database holding TABLE */
+  Db *pDb;              /* The database containing table being inserted into */
+  int appendFlag = 0;   /* True if the insert is likely to be an append */
+
+  /* Register allocations */
+  int regFromSelect;    /* Base register for data coming from SELECT */
+  int regAutoinc = 0;   /* Register holding the AUTOINCREMENT counter */
+  int regRowCount = 0;  /* Memory cell used for the row counter */
+  int regIns;           /* Block of regs holding rowid+data being inserted */
+  int regRowid;         /* registers holding insert rowid */
+  int regData;          /* register holding first column to insert */
+  int regRecord;        /* Holds the assemblied row record */
+  int regEof;           /* Register recording end of SELECT data */
+  int *aRegIdx = 0;     /* One register allocated to each index */
+
+
+#ifndef SQLITE_OMIT_TRIGGER
+  int isView;                 /* True if attempting to insert into a view */
+  int triggers_exist = 0;     /* True if there are FOR EACH ROW triggers */
+#endif
+
+  db = pParse->db;
+  if( pParse->nErr || db->mallocFailed ){
+    goto insert_cleanup;
+  }
+
+  /* Locate the table into which we will be inserting new information.
+  */
+  assert( pTabList->nSrc==1 );
+  zTab = pTabList->a[0].zName;
+  if( zTab==0 ) goto insert_cleanup;
+  pTab = sqlite3SrcListLookup(pParse, pTabList);
+  if( pTab==0 ){
+    goto insert_cleanup;
+  }
+  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+  assert( iDb<db->nDb );
+  pDb = &db->aDb[iDb];
+  zDb = pDb->zName;
+  if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0, zDb) ){
+    goto insert_cleanup;
+  }
+
+  /* Figure out if we have any triggers and if the table being
+  ** inserted into is a view
+  */
+#ifndef SQLITE_OMIT_TRIGGER
+  triggers_exist = sqlite3TriggersExist(pParse, pTab, TK_INSERT, 0);
+  isView = pTab->pSelect!=0;
+#else
+# define triggers_exist 0
+# define isView 0
+#endif
+#ifdef SQLITE_OMIT_VIEW
+# undef isView
+# define isView 0
+#endif
+
+  /* Ensure that:
+  *  (a) the table is not read-only, 
+  *  (b) that if it is a view then ON INSERT triggers exist
+  */
+  if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
+    goto insert_cleanup;
+  }
+  assert( pTab!=0 );
+
+  /* If pTab is really a view, make sure it has been initialized.
+  ** ViewGetColumnNames() is a no-op if pTab is not a view (or virtual 
+  ** module table).
+  */
+  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
+    goto insert_cleanup;
+  }
+
+  /* Allocate a VDBE
+  */
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 ) goto insert_cleanup;
+  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
+  sqlite3BeginWriteOperation(pParse, pSelect || triggers_exist, iDb);
+
+  /* if there are row triggers, allocate a temp table for new.* references. */
+  if( triggers_exist ){
+    newIdx = pParse->nTab++;
+  }
+
+#ifndef SQLITE_OMIT_XFER_OPT
+  /* If the statement is of the form
+  **
+  **       INSERT INTO <table1> SELECT * FROM <table2>;
+  **
+  ** Then special optimizations can be applied that make the transfer
+  ** very fast and which reduce fragmentation of indices.
+  **
+  ** This is the 2nd template.
+  */
+  if( pColumn==0 && xferOptimization(pParse, pTab, pSelect, onError, iDb) ){
+    assert( !triggers_exist );
+    assert( pList==0 );
+    goto insert_cleanup;
+  }
+#endif /* SQLITE_OMIT_XFER_OPT */
+
+  /* If this is an AUTOINCREMENT table, look up the sequence number in the
+  ** sqlite_sequence table and store it in memory cell regAutoinc.
+  */
+  regAutoinc = autoIncBegin(pParse, iDb, pTab);
+
+  /* Figure out how many columns of data are supplied.  If the data
+  ** is coming from a SELECT statement, then generate a co-routine that
+  ** produces a single row of the SELECT on each invocation.  The
+  ** co-routine is the common header to the 3rd and 4th templates.
+  */
+  if( pSelect ){
+    /* Data is coming from a SELECT.  Generate code to implement that SELECT
+    ** as a co-routine.  The code is common to both the 3rd and 4th
+    ** templates:
+    **
+    **         EOF <- 0
+    **         X <- A
+    **         goto B
+    **      A: setup for the SELECT
+    **         loop over the tables in the SELECT
+    **           load value into register R..R+n
+    **           yield X
+    **         end loop
+    **         cleanup after the SELECT
+    **         EOF <- 1
+    **         yield X
+    **         halt-error
+    **
+    ** On each invocation of the co-routine, it puts a single row of the
+    ** SELECT result into registers dest.iMem...dest.iMem+dest.nMem-1.
+    ** (These output registers are allocated by sqlite3Select().)  When
+    ** the SELECT completes, it sets the EOF flag stored in regEof.
+    */
+    int rc, j1;
+
+    regEof = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, regEof);      /* EOF <- 0 */
+    VdbeComment((v, "SELECT eof flag"));
+    sqlite3SelectDestInit(&dest, SRT_Coroutine, ++pParse->nMem);
+    addrSelect = sqlite3VdbeCurrentAddr(v)+2;
+    sqlite3VdbeAddOp2(v, OP_Integer, addrSelect-1, dest.iParm);
+    j1 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
+    VdbeComment((v, "Jump over SELECT coroutine"));
+
+    /* Resolve the expressions in the SELECT statement and execute it. */
+    rc = sqlite3Select(pParse, pSelect, &dest, 0, 0, 0);
+    if( rc || pParse->nErr || db->mallocFailed ){
+      goto insert_cleanup;
+    }
+    sqlite3VdbeAddOp2(v, OP_Integer, 1, regEof);         /* EOF <- 1 */
+    sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);   /* yield X */
+    sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_INTERNAL, OE_Abort);
+    VdbeComment((v, "End of SELECT coroutine"));
+    sqlite3VdbeJumpHere(v, j1);                          /* label B: */
+
+    regFromSelect = dest.iMem;
+    assert( pSelect->pEList );
+    nColumn = pSelect->pEList->nExpr;
+    assert( dest.nMem==nColumn );
+
+    /* Set useTempTable to TRUE if the result of the SELECT statement
+    ** should be written into a temporary table (template 4).  Set to
+    ** FALSE if each* row of the SELECT can be written directly into
+    ** the destination table (template 3).
+    **
+    ** A temp table must be used if the table being updated is also one
+    ** of the tables being read by the SELECT statement.  Also use a 
+    ** temp table in the case of row triggers.
+    */
+    if( triggers_exist || readsTable(v, addrSelect, iDb, pTab) ){
+      useTempTable = 1;
+    }
+
+    if( useTempTable ){
+      /* Invoke the coroutine to extract information from the SELECT
+      ** and add it to a transient table srcTab.  The code generated
+      ** here is from the 4th template:
+      **
+      **      B: open temp table
+      **      L: yield X
+      **         if EOF goto M
+      **         insert row from R..R+n into temp table
+      **         goto L
+      **      M: ...
+      */
+      int regRec;      /* Register to hold packed record */
+      int regRowid;    /* Register to hold temp table ROWID */
+      int addrTop;     /* Label "L" */
+      int addrIf;      /* Address of jump to M */
+
+      srcTab = pParse->nTab++;
+      regRec = sqlite3GetTempReg(pParse);
+      regRowid = sqlite3GetTempReg(pParse);
+      sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
+      addrTop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);
+      addrIf = sqlite3VdbeAddOp1(v, OP_If, regEof);
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
+      sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regRowid);
+      sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regRowid);
+      sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop);
+      sqlite3VdbeJumpHere(v, addrIf);
+      sqlite3ReleaseTempReg(pParse, regRec);
+      sqlite3ReleaseTempReg(pParse, regRowid);
+    }
+  }else{
+    /* This is the case if the data for the INSERT is coming from a VALUES
+    ** clause
+    */
+    NameContext sNC;
+    memset(&sNC, 0, sizeof(sNC));
+    sNC.pParse = pParse;
+    srcTab = -1;
+    assert( useTempTable==0 );
+    nColumn = pList ? pList->nExpr : 0;
+    for(i=0; i<nColumn; i++){
+      if( sqlite3ExprResolveNames(&sNC, pList->a[i].pExpr) ){
+        goto insert_cleanup;
+      }
+    }
+  }
+
+  /* Make sure the number of columns in the source data matches the number
+  ** of columns to be inserted into the table.
+  */
+  if( IsVirtual(pTab) ){
+    for(i=0; i<pTab->nCol; i++){
+      nHidden += (IsHiddenColumn(&pTab->aCol[i]) ? 1 : 0);
+    }
+  }
+  if( pColumn==0 && nColumn && nColumn!=(pTab->nCol-nHidden) ){
+    sqlite3ErrorMsg(pParse, 
+       "table %S has %d columns but %d values were supplied",
+       pTabList, 0, pTab->nCol, nColumn);
+    goto insert_cleanup;
+  }
+  if( pColumn!=0 && nColumn!=pColumn->nId ){
+    sqlite3ErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);
+    goto insert_cleanup;
+  }
+
+  /* If the INSERT statement included an IDLIST term, then make sure
+  ** all elements of the IDLIST really are columns of the table and 
+  ** remember the column indices.
+  **
+  ** If the table has an INTEGER PRIMARY KEY column and that column
+  ** is named in the IDLIST, then record in the keyColumn variable
+  ** the index into IDLIST of the primary key column.  keyColumn is
+  ** the index of the primary key as it appears in IDLIST, not as
+  ** is appears in the original table.  (The index of the primary
+  ** key in the original table is pTab->iPKey.)
+  */
+  if( pColumn ){
+    for(i=0; i<pColumn->nId; i++){
+      pColumn->a[i].idx = -1;
+    }
+    for(i=0; i<pColumn->nId; i++){
+      for(j=0; j<pTab->nCol; j++){
+        if( sqlite3StrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
+          pColumn->a[i].idx = j;
+          if( j==pTab->iPKey ){
+            keyColumn = i;
+          }
+          break;
+        }
+      }
+      if( j>=pTab->nCol ){
+        if( sqlite3IsRowid(pColumn->a[i].zName) ){
+          keyColumn = i;
+        }else{
+          sqlite3ErrorMsg(pParse, "table %S has no column named %s",
+              pTabList, 0, pColumn->a[i].zName);
+          pParse->nErr++;
+          goto insert_cleanup;
+        }
+      }
+    }
+  }
+
+  /* If there is no IDLIST term but the table has an integer primary
+  ** key, the set the keyColumn variable to the primary key column index
+  ** in the original table definition.
+  */
+  if( pColumn==0 && nColumn>0 ){
+    keyColumn = pTab->iPKey;
+  }
+
+  /* Open the temp table for FOR EACH ROW triggers
+  */
+  if( triggers_exist ){
+    sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
+    sqlite3VdbeAddOp2(v, OP_OpenPseudo, newIdx, 0);
+  }
+    
+  /* Initialize the count of rows to be inserted
+  */
+  if( db->flags & SQLITE_CountRows ){
+    regRowCount = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
+  }
+
+  /* If this is not a view, open the table and and all indices */
+  if( !isView ){
+    int nIdx;
+    int i;
+
+    baseCur = pParse->nTab;
+    nIdx = sqlite3OpenTableAndIndices(pParse, pTab, baseCur, OP_OpenWrite);
+    aRegIdx = sqlite3DbMallocRaw(db, sizeof(int)*(nIdx+1));
+    if( aRegIdx==0 ){
+      goto insert_cleanup;
+    }
+    for(i=0; i<nIdx; i++){
+      aRegIdx[i] = ++pParse->nMem;
+    }
+  }
+
+  /* This is the top of the main insertion loop */
+  if( useTempTable ){
+    /* This block codes the top of loop only.  The complete loop is the
+    ** following pseudocode (template 4):
+    **
+    **         rewind temp table
+    **      C: loop over rows of intermediate table
+    **           transfer values form intermediate table into <table>
+    **         end loop
+    **      D: ...
+    */
+    addrInsTop = sqlite3VdbeAddOp1(v, OP_Rewind, srcTab);
+    addrCont = sqlite3VdbeCurrentAddr(v);
+  }else if( pSelect ){
+    /* This block codes the top of loop only.  The complete loop is the
+    ** following pseudocode (template 3):
+    **
+    **      C: yield X
+    **         if EOF goto D
+    **         insert the select result into <table> from R..R+n
+    **         goto C
+    **      D: ...
+    */
+    addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);
+    addrInsTop = sqlite3VdbeAddOp1(v, OP_If, regEof);
+  }
+
+  /* Allocate registers for holding the rowid of the new row,
+  ** the content of the new row, and the assemblied row record.
+  */
+  regRecord = ++pParse->nMem;
+  regRowid = regIns = pParse->nMem+1;
+  pParse->nMem += pTab->nCol + 1;
+  if( IsVirtual(pTab) ){
+    regRowid++;
+    pParse->nMem++;
+  }
+  regData = regRowid+1;
+
+  /* Run the BEFORE and INSTEAD OF triggers, if there are any
+  */
+  endOfLoop = sqlite3VdbeMakeLabel(v);
+  if( triggers_exist & TRIGGER_BEFORE ){
+    int regRowid;
+    int regCols;
+    int regRec;
+
+    /* build the NEW.* reference row.  Note that if there is an INTEGER
+    ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
+    ** translated into a unique ID for the row.  But on a BEFORE trigger,
+    ** we do not know what the unique ID will be (because the insert has
+    ** not happened yet) so we substitute a rowid of -1
+    */
+    regRowid = sqlite3GetTempReg(pParse);
+    if( keyColumn<0 ){
+      sqlite3VdbeAddOp2(v, OP_Integer, -1, regRowid);
+    }else if( useTempTable ){
+      sqlite3VdbeAddOp3(v, OP_Column, srcTab, keyColumn, regRowid);
+    }else{
+      int j1;
+      assert( pSelect==0 );  /* Otherwise useTempTable is true */
+      sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, regRowid);
+      j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid);
+      sqlite3VdbeAddOp2(v, OP_Integer, -1, regRowid);
+      sqlite3VdbeJumpHere(v, j1);
+      sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid);
+    }
+
+    /* Cannot have triggers on a virtual table. If it were possible,
+    ** this block would have to account for hidden column.
+    */
+    assert(!IsVirtual(pTab));
+
+    /* Create the new column data
+    */
+    regCols = sqlite3GetTempRange(pParse, pTab->nCol);
+    for(i=0; i<pTab->nCol; i++){
+      if( pColumn==0 ){
+        j = i;
+      }else{
+        for(j=0; j<pColumn->nId; j++){
+          if( pColumn->a[j].idx==i ) break;
+        }
+      }
+      if( pColumn && j>=pColumn->nId ){
+        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regCols+i);
+      }else if( useTempTable ){
+        sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, regCols+i); 
+      }else{
+        assert( pSelect==0 ); /* Otherwise useTempTable is true */
+        sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr, regCols+i);
+      }
+    }
+    regRec = sqlite3GetTempReg(pParse);
+    sqlite3VdbeAddOp3(v, OP_MakeRecord, regCols, pTab->nCol, regRec);
+
+    /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
+    ** do not attempt any conversions before assembling the record.
+    ** If this is a real table, attempt conversions as required by the
+    ** table column affinities.
+    */
+    if( !isView ){
+      sqlite3TableAffinityStr(v, pTab);
+    }
+    sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRec, regRowid);
+    sqlite3ReleaseTempReg(pParse, regRec);
+    sqlite3ReleaseTempReg(pParse, regRowid);
+    sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol);
+
+    /* Fire BEFORE or INSTEAD OF triggers */
+    if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_BEFORE, pTab, 
+        newIdx, -1, onError, endOfLoop, 0, 0) ){
+      goto insert_cleanup;
+    }
+  }
+
+  /* Push the record number for the new entry onto the stack.  The
+  ** record number is a randomly generate integer created by NewRowid
+  ** except when the table has an INTEGER PRIMARY KEY column, in which
+  ** case the record number is the same as that column. 
+  */
+  if( !isView ){
+    if( IsVirtual(pTab) ){
+      /* The row that the VUpdate opcode will delete: none */
+      sqlite3VdbeAddOp2(v, OP_Null, 0, regIns);
+    }
+    if( keyColumn>=0 ){
+      if( useTempTable ){
+        sqlite3VdbeAddOp3(v, OP_Column, srcTab, keyColumn, regRowid);
+      }else if( pSelect ){
+        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+keyColumn, regRowid);
+      }else{
+        VdbeOp *pOp;
+        sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, regRowid);
+        pOp = sqlite3VdbeGetOp(v, sqlite3VdbeCurrentAddr(v) - 1);
+        if( pOp && pOp->opcode==OP_Null && !IsVirtual(pTab) ){
+          appendFlag = 1;
+          pOp->opcode = OP_NewRowid;
+          pOp->p1 = baseCur;
+          pOp->p2 = regRowid;
+          pOp->p3 = regAutoinc;
+        }
+      }
+      /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
+      ** to generate a unique primary key value.
+      */
+      if( !appendFlag ){
+        int j1;
+        if( !IsVirtual(pTab) ){
+          j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid);
+          sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
+          sqlite3VdbeJumpHere(v, j1);
+        }else{
+          j1 = sqlite3VdbeCurrentAddr(v);
+          sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, j1+2);
+        }
+        sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid);
+      }
+    }else if( IsVirtual(pTab) ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);
+    }else{
+      sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
+      appendFlag = 1;
+    }
+    autoIncStep(pParse, regAutoinc, regRowid);
+
+    /* Push onto the stack, data for all columns of the new entry, beginning
+    ** with the first column.
+    */
+    nHidden = 0;
+    for(i=0; i<pTab->nCol; i++){
+      int iRegStore = regRowid+1+i;
+      if( i==pTab->iPKey ){
+        /* The value of the INTEGER PRIMARY KEY column is always a NULL.
+        ** Whenever this column is read, the record number will be substituted
+        ** in its place.  So will fill this column with a NULL to avoid
+        ** taking up data space with information that will never be used. */
+        sqlite3VdbeAddOp2(v, OP_Null, 0, iRegStore);
+        continue;
+      }
+      if( pColumn==0 ){
+        if( IsHiddenColumn(&pTab->aCol[i]) ){
+          assert( IsVirtual(pTab) );
+          j = -1;
+          nHidden++;
+        }else{
+          j = i - nHidden;
+        }
+      }else{
+        for(j=0; j<pColumn->nId; j++){
+          if( pColumn->a[j].idx==i ) break;
+        }
+      }
+      if( j<0 || nColumn==0 || (pColumn && j>=pColumn->nId) ){
+        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, iRegStore);
+      }else if( useTempTable ){
+        sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, iRegStore); 
+      }else if( pSelect ){
+        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+j, iRegStore);
+      }else{
+        sqlite3ExprCode(pParse, pList->a[j].pExpr, iRegStore);
+      }
+    }
+
+    /* Generate code to check constraints and generate index keys and
+    ** do the insertion.
+    */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( IsVirtual(pTab) ){
+      sqlite3VtabMakeWritable(pParse, pTab);
+      sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns,
+                     (const char*)pTab->pVtab, P4_VTAB);
+    }else
+#endif
+    {
+      sqlite3GenerateConstraintChecks(
+          pParse,
+          pTab,
+          baseCur,
+          regIns,
+          aRegIdx,
+          keyColumn>=0,
+          0,
+          onError,
+          endOfLoop
+      );
+      sqlite3CompleteInsertion(
+          pParse,
+          pTab,
+          baseCur,
+          regIns,
+          aRegIdx,
+          0,
+          0,
+          (triggers_exist & TRIGGER_AFTER)!=0 ? newIdx : -1,
+          appendFlag
+       );
+    }
+  }
+
+  /* Update the count of rows that are inserted
+  */
+  if( (db->flags & SQLITE_CountRows)!=0 ){
+    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
+  }
+
+  if( triggers_exist ){
+    /* Code AFTER triggers */
+    if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_AFTER, pTab,
+          newIdx, -1, onError, endOfLoop, 0, 0) ){
+      goto insert_cleanup;
+    }
+  }
+
+  /* The bottom of the main insertion loop, if the data source
+  ** is a SELECT statement.
+  */
+  sqlite3VdbeResolveLabel(v, endOfLoop);
+  if( useTempTable ){
+    sqlite3VdbeAddOp2(v, OP_Next, srcTab, addrCont);
+    sqlite3VdbeJumpHere(v, addrInsTop);
+    sqlite3VdbeAddOp1(v, OP_Close, srcTab);
+  }else if( pSelect ){
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrCont);
+    sqlite3VdbeJumpHere(v, addrInsTop);
+  }
+
+  if( !IsVirtual(pTab) && !isView ){
+    /* Close all tables opened */
+    sqlite3VdbeAddOp1(v, OP_Close, baseCur);
+    for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
+      sqlite3VdbeAddOp1(v, OP_Close, idx+baseCur);
+    }
+  }
+
+  /* Update the sqlite_sequence table by storing the content of the
+  ** counter value in memory regAutoinc back into the sqlite_sequence
+  ** table.
+  */
+  autoIncEnd(pParse, iDb, pTab, regAutoinc);
+
+  /*
+  ** Return the number of rows inserted. If this routine is 
+  ** generating code because of a call to sqlite3NestedParse(), do not
+  ** invoke the callback function.
+  */
+  if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
+    sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
+    sqlite3VdbeSetNumCols(v, 1);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows inserted", P4_STATIC);
+  }
+
+insert_cleanup:
+  sqlite3SrcListDelete(db, pTabList);
+  sqlite3ExprListDelete(db, pList);
+  sqlite3SelectDelete(db, pSelect);
+  sqlite3IdListDelete(db, pColumn);
+  sqlite3DbFree(db, aRegIdx);
+}
+
+/*
+** Generate code to do constraint checks prior to an INSERT or an UPDATE.
+**
+** The input is a range of consecutive registers as follows:
+**
+**    1.  The rowid of the row to be updated before the update.  This
+**        value is omitted unless we are doing an UPDATE that involves a
+**        change to the record number or writing to a virtual table.
+**
+**    2.  The rowid of the row after the update.
+**
+**    3.  The data in the first column of the entry after the update.
+**
+**    i.  Data from middle columns...
+**
+**    N.  The data in the last column of the entry after the update.
+**
+** The regRowid parameter is the index of the register containing (2).
+**
+** The old rowid shown as entry (1) above is omitted unless both isUpdate
+** and rowidChng are 1.  isUpdate is true for UPDATEs and false for
+** INSERTs.  RowidChng means that the new rowid is explicitly specified by
+** the update or insert statement.  If rowidChng is false, it means that
+** the rowid is computed automatically in an insert or that the rowid value
+** is not modified by the update.
+**
+** The code generated by this routine store new index entries into
+** registers identified by aRegIdx[].  No index entry is created for
+** indices where aRegIdx[i]==0.  The order of indices in aRegIdx[] is
+** the same as the order of indices on the linked list of indices
+** attached to the table.
+**
+** This routine also generates code to check constraints.  NOT NULL,
+** CHECK, and UNIQUE constraints are all checked.  If a constraint fails,
+** then the appropriate action is performed.  There are five possible
+** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
+**
+**  Constraint type  Action       What Happens
+**  ---------------  ----------   ----------------------------------------
+**  any              ROLLBACK     The current transaction is rolled back and
+**                                sqlite3_exec() returns immediately with a
+**                                return code of SQLITE_CONSTRAINT.
+**
+**  any              ABORT        Back out changes from the current command
+**                                only (do not do a complete rollback) then
+**                                cause sqlite3_exec() to return immediately
+**                                with SQLITE_CONSTRAINT.
+**
+**  any              FAIL         Sqlite_exec() returns immediately with a
+**                                return code of SQLITE_CONSTRAINT.  The
+**                                transaction is not rolled back and any
+**                                prior changes are retained.
+**
+**  any              IGNORE       The record number and data is popped from
+**                                the stack and there is an immediate jump
+**                                to label ignoreDest.
+**
+**  NOT NULL         REPLACE      The NULL value is replace by the default
+**                                value for that column.  If the default value
+**                                is NULL, the action is the same as ABORT.
+**
+**  UNIQUE           REPLACE      The other row that conflicts with the row
+**                                being inserted is removed.
+**
+**  CHECK            REPLACE      Illegal.  The results in an exception.
+**
+** Which action to take is determined by the overrideError parameter.
+** Or if overrideError==OE_Default, then the pParse->onError parameter
+** is used.  Or if pParse->onError==OE_Default then the onError value
+** for the constraint is used.
+**
+** The calling routine must open a read/write cursor for pTab with
+** cursor number "baseCur".  All indices of pTab must also have open
+** read/write cursors with cursor number baseCur+i for the i-th cursor.
+** Except, if there is no possibility of a REPLACE action then
+** cursors do not need to be open for indices where aRegIdx[i]==0.
+*/
+void sqlite3GenerateConstraintChecks(
+  Parse *pParse,      /* The parser context */
+  Table *pTab,        /* the table into which we are inserting */
+  int baseCur,        /* Index of a read/write cursor pointing at pTab */
+  int regRowid,       /* Index of the range of input registers */
+  int *aRegIdx,       /* Register used by each index.  0 for unused indices */
+  int rowidChng,      /* True if the rowid might collide with existing entry */
+  int isUpdate,       /* True for UPDATE, False for INSERT */
+  int overrideError,  /* Override onError to this if not OE_Default */
+  int ignoreDest      /* Jump to this label on an OE_Ignore resolution */
+){
+  int i;
+  Vdbe *v;
+  int nCol;
+  int onError;
+  int j1, j2, j3;     /* Addresses of jump instructions */
+  int regData;        /* Register containing first data column */
+  int iCur;
+  Index *pIdx;
+  int seenReplace = 0;
+  int hasTwoRowids = (isUpdate && rowidChng);
+
+  v = sqlite3GetVdbe(pParse);
+  assert( v!=0 );
+  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
+  nCol = pTab->nCol;
+  regData = regRowid + 1;
+
+
+  /* Test all NOT NULL constraints.
+  */
+  for(i=0; i<nCol; i++){
+    if( i==pTab->iPKey ){
+      continue;
+    }
+    onError = pTab->aCol[i].notNull;
+    if( onError==OE_None ) continue;
+    if( overrideError!=OE_Default ){
+      onError = overrideError;
+    }else if( onError==OE_Default ){
+      onError = OE_Abort;
+    }
+    if( onError==OE_Replace && pTab->aCol[i].pDflt==0 ){
+      onError = OE_Abort;
+    }
+    j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regData+i);
+    assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
+        || onError==OE_Ignore || onError==OE_Replace );
+    switch( onError ){
+      case OE_Rollback:
+      case OE_Abort:
+      case OE_Fail: {
+        char *zMsg;
+        sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_CONSTRAINT, onError);
+        zMsg = sqlite3MPrintf(pParse->db, "%s.%s may not be NULL",
+                              pTab->zName, pTab->aCol[i].zName);
+        sqlite3VdbeChangeP4(v, -1, zMsg, P4_DYNAMIC);
+        break;
+      }
+      case OE_Ignore: {
+        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
+        break;
+      }
+      case OE_Replace: {
+        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regData+i);
+        break;
+      }
+    }
+    sqlite3VdbeJumpHere(v, j1);
+  }
+
+  /* Test all CHECK constraints
+  */
+#ifndef SQLITE_OMIT_CHECK
+  if( pTab->pCheck && (pParse->db->flags & SQLITE_IgnoreChecks)==0 ){
+    int allOk = sqlite3VdbeMakeLabel(v);
+    pParse->ckBase = regData;
+    sqlite3ExprIfTrue(pParse, pTab->pCheck, allOk, SQLITE_JUMPIFNULL);
+    onError = overrideError!=OE_Default ? overrideError : OE_Abort;
+    if( onError==OE_Ignore ){
+      sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
+    }else{
+      sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_CONSTRAINT, onError);
+    }
+    sqlite3VdbeResolveLabel(v, allOk);
+  }
+#endif /* !defined(SQLITE_OMIT_CHECK) */
+
+  /* If we have an INTEGER PRIMARY KEY, make sure the primary key
+  ** of the new record does not previously exist.  Except, if this
+  ** is an UPDATE and the primary key is not changing, that is OK.
+  */
+  if( rowidChng ){
+    onError = pTab->keyConf;
+    if( overrideError!=OE_Default ){
+      onError = overrideError;
+    }else if( onError==OE_Default ){
+      onError = OE_Abort;
+    }
+    
+    if( onError!=OE_Replace || pTab->pIndex ){
+      if( isUpdate ){
+        j2 = sqlite3VdbeAddOp3(v, OP_Eq, regRowid, 0, regRowid-1);
+      }
+      j3 = sqlite3VdbeAddOp3(v, OP_NotExists, baseCur, 0, regRowid);
+      switch( onError ){
+        default: {
+          onError = OE_Abort;
+          /* Fall thru into the next case */
+        }
+        case OE_Rollback:
+        case OE_Abort:
+        case OE_Fail: {
+          sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0,
+                           "PRIMARY KEY must be unique", P4_STATIC);
+          break;
+        }
+        case OE_Replace: {
+          sqlite3GenerateRowIndexDelete(pParse, pTab, baseCur, 0);
+          seenReplace = 1;
+          break;
+        }
+        case OE_Ignore: {
+          assert( seenReplace==0 );
+          sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
+          break;
+        }
+      }
+      sqlite3VdbeJumpHere(v, j3);
+      if( isUpdate ){
+        sqlite3VdbeJumpHere(v, j2);
+      }
+    }
+  }
+
+  /* Test all UNIQUE constraints by creating entries for each UNIQUE
+  ** index and making sure that duplicate entries do not already exist.
+  ** Add the new records to the indices as we go.
+  */
+  for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){
+    int regIdx;
+    int regR;
+
+    if( aRegIdx[iCur]==0 ) continue;  /* Skip unused indices */
+
+    /* Create a key for accessing the index entry */
+    regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn+1);
+    for(i=0; i<pIdx->nColumn; i++){
+      int idx = pIdx->aiColumn[i];
+      if( idx==pTab->iPKey ){
+        sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
+      }else{
+        sqlite3VdbeAddOp2(v, OP_SCopy, regData+idx, regIdx+i);
+      }
+    }
+    sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
+    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn+1, aRegIdx[iCur]);
+    sqlite3IndexAffinityStr(v, pIdx);
+    sqlite3ExprCacheAffinityChange(pParse, regIdx, pIdx->nColumn+1);
+    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);
+
+    /* Find out what action to take in case there is an indexing conflict */
+    onError = pIdx->onError;
+    if( onError==OE_None ) continue;  /* pIdx is not a UNIQUE index */
+    if( overrideError!=OE_Default ){
+      onError = overrideError;
+    }else if( onError==OE_Default ){
+      onError = OE_Abort;
+    }
+    if( seenReplace ){
+      if( onError==OE_Ignore ) onError = OE_Replace;
+      else if( onError==OE_Fail ) onError = OE_Abort;
+    }
+    
+
+    /* Check to see if the new index entry will be unique */
+    j2 = sqlite3VdbeAddOp3(v, OP_IsNull, regIdx, 0, pIdx->nColumn);
+    regR = sqlite3GetTempReg(pParse);
+    sqlite3VdbeAddOp2(v, OP_SCopy, regRowid-hasTwoRowids, regR);
+    j3 = sqlite3VdbeAddOp4(v, OP_IsUnique, baseCur+iCur+1, 0,
+                           regR, SQLITE_INT_TO_PTR(aRegIdx[iCur]),
+                           P4_INT32);
+
+    /* Generate code that executes if the new index entry is not unique */
+    assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
+        || onError==OE_Ignore || onError==OE_Replace );
+    switch( onError ){
+      case OE_Rollback:
+      case OE_Abort:
+      case OE_Fail: {
+        int j, n1, n2;
+        char zErrMsg[200];
+        sqlite3_snprintf(sizeof(zErrMsg), zErrMsg,
+                         pIdx->nColumn>1 ? "columns " : "column ");
+        n1 = strlen(zErrMsg);
+        for(j=0; j<pIdx->nColumn && n1<sizeof(zErrMsg)-30; j++){
+          char *zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
+          n2 = strlen(zCol);
+          if( j>0 ){
+            sqlite3_snprintf(sizeof(zErrMsg)-n1, &zErrMsg[n1], ", ");
+            n1 += 2;
+          }
+          if( n1+n2>sizeof(zErrMsg)-30 ){
+            sqlite3_snprintf(sizeof(zErrMsg)-n1, &zErrMsg[n1], "...");
+            n1 += 3;
+            break;
+          }else{
+            sqlite3_snprintf(sizeof(zErrMsg)-n1, &zErrMsg[n1], "%s", zCol);
+            n1 += n2;
+          }
+        }
+        sqlite3_snprintf(sizeof(zErrMsg)-n1, &zErrMsg[n1], 
+            pIdx->nColumn>1 ? " are not unique" : " is not unique");
+        sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0, zErrMsg,0);
+        break;
+      }
+      case OE_Ignore: {
+        assert( seenReplace==0 );
+        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
+        break;
+      }
+      case OE_Replace: {
+        sqlite3GenerateRowDelete(pParse, pTab, baseCur, regR, 0);
+        seenReplace = 1;
+        break;
+      }
+    }
+    sqlite3VdbeJumpHere(v, j2);
+    sqlite3VdbeJumpHere(v, j3);
+    sqlite3ReleaseTempReg(pParse, regR);
+  }
+}
+
+/*
+** This routine generates code to finish the INSERT or UPDATE operation
+** that was started by a prior call to sqlite3GenerateConstraintChecks.
+** A consecutive range of registers starting at regRowid contains the
+** rowid and the content to be inserted.
+**
+** The arguments to this routine should be the same as the first six
+** arguments to sqlite3GenerateConstraintChecks.
+*/
+void sqlite3CompleteInsertion(
+  Parse *pParse,      /* The parser context */
+  Table *pTab,        /* the table into which we are inserting */
+  int baseCur,        /* Index of a read/write cursor pointing at pTab */
+  int regRowid,       /* Range of content */
+  int *aRegIdx,       /* Register used by each index.  0 for unused indices */
+  int rowidChng,      /* True if the record number will change */
+  int isUpdate,       /* True for UPDATE, False for INSERT */
+  int newIdx,         /* Index of NEW table for triggers.  -1 if none */
+  int appendBias      /* True if this is likely to be an append */
+){
+  int i;
+  Vdbe *v;
+  int nIdx;
+  Index *pIdx;
+  int pik_flags;
+  int regData;
+  int regRec;
+
+  v = sqlite3GetVdbe(pParse);
+  assert( v!=0 );
+  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
+  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
+  for(i=nIdx-1; i>=0; i--){
+    if( aRegIdx[i]==0 ) continue;
+    sqlite3VdbeAddOp2(v, OP_IdxInsert, baseCur+i+1, aRegIdx[i]);
+  }
+  regData = regRowid + 1;
+  regRec = sqlite3GetTempReg(pParse);
+  sqlite3VdbeAddOp3(v, OP_MakeRecord, regData, pTab->nCol, regRec);
+  sqlite3TableAffinityStr(v, pTab);
+  sqlite3ExprCacheAffinityChange(pParse, regData, pTab->nCol);
+#ifndef SQLITE_OMIT_TRIGGER
+  if( newIdx>=0 ){
+    sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRec, regRowid);
+  }
+#endif
+  if( pParse->nested ){
+    pik_flags = 0;
+  }else{
+    pik_flags = OPFLAG_NCHANGE;
+    pik_flags |= (isUpdate?OPFLAG_ISUPDATE:OPFLAG_LASTROWID);
+  }
+  if( appendBias ){
+    pik_flags |= OPFLAG_APPEND;
+  }
+  sqlite3VdbeAddOp3(v, OP_Insert, baseCur, regRec, regRowid);
+  if( !pParse->nested ){
+    sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
+  }
+  sqlite3VdbeChangeP5(v, pik_flags);
+}
+
+/*
+** Generate code that will open cursors for a table and for all
+** indices of that table.  The "baseCur" parameter is the cursor number used
+** for the table.  Indices are opened on subsequent cursors.
+**
+** Return the number of indices on the table.
+*/
+int sqlite3OpenTableAndIndices(
+  Parse *pParse,   /* Parsing context */
+  Table *pTab,     /* Table to be opened */
+  int baseCur,        /* Cursor number assigned to the table */
+  int op           /* OP_OpenRead or OP_OpenWrite */
+){
+  int i;
+  int iDb;
+  Index *pIdx;
+  Vdbe *v;
+
+  if( IsVirtual(pTab) ) return 0;
+  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+  v = sqlite3GetVdbe(pParse);
+  assert( v!=0 );
+  sqlite3OpenTable(pParse, baseCur, iDb, pTab, op);
+  for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
+    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
+    assert( pIdx->pSchema==pTab->pSchema );
+    sqlite3VdbeAddOp4(v, op, i+baseCur, pIdx->tnum, iDb,
+                      (char*)pKey, P4_KEYINFO_HANDOFF);
+    VdbeComment((v, "%s", pIdx->zName));
+  }
+  if( pParse->nTab<=baseCur+i ){
+    pParse->nTab = baseCur+i;
+  }
+  return i-1;
+}
+
+
+#ifdef SQLITE_TEST
+/*
+** The following global variable is incremented whenever the
+** transfer optimization is used.  This is used for testing
+** purposes only - to make sure the transfer optimization really
+** is happening when it is suppose to.
+*/
+int sqlite3_xferopt_count;
+#endif /* SQLITE_TEST */
+
+
+#ifndef SQLITE_OMIT_XFER_OPT
+/*
+** Check to collation names to see if they are compatible.
+*/
+static int xferCompatibleCollation(const char *z1, const char *z2){
+  if( z1==0 ){
+    return z2==0;
+  }
+  if( z2==0 ){
+    return 0;
+  }
+  return sqlite3StrICmp(z1, z2)==0;
+}
+
+
+/*
+** Check to see if index pSrc is compatible as a source of data
+** for index pDest in an insert transfer optimization.  The rules
+** for a compatible index:
+**
+**    *   The index is over the same set of columns
+**    *   The same DESC and ASC markings occurs on all columns
+**    *   The same onError processing (OE_Abort, OE_Ignore, etc)
+**    *   The same collating sequence on each column
+*/
+static int xferCompatibleIndex(Index *pDest, Index *pSrc){
+  int i;
+  assert( pDest && pSrc );
+  assert( pDest->pTable!=pSrc->pTable );
+  if( pDest->nColumn!=pSrc->nColumn ){
+    return 0;   /* Different number of columns */
+  }
+  if( pDest->onError!=pSrc->onError ){
+    return 0;   /* Different conflict resolution strategies */
+  }
+  for(i=0; i<pSrc->nColumn; i++){
+    if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
+      return 0;   /* Different columns indexed */
+    }
+    if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
+      return 0;   /* Different sort orders */
+    }
+    if( pSrc->azColl[i]!=pDest->azColl[i] ){
+      return 0;   /* Different collating sequences */
+    }
+  }
+
+  /* If no test above fails then the indices must be compatible */
+  return 1;
+}
+
+/*
+** Attempt the transfer optimization on INSERTs of the form
+**
+**     INSERT INTO tab1 SELECT * FROM tab2;
+**
+** This optimization is only attempted if
+**
+**    (1)  tab1 and tab2 have identical schemas including all the
+**         same indices and constraints
+**
+**    (2)  tab1 and tab2 are different tables
+**
+**    (3)  There must be no triggers on tab1
+**
+**    (4)  The result set of the SELECT statement is "*"
+**
+**    (5)  The SELECT statement has no WHERE, HAVING, ORDER BY, GROUP BY,
+**         or LIMIT clause.
+**
+**    (6)  The SELECT statement is a simple (not a compound) select that
+**         contains only tab2 in its FROM clause
+**
+** This method for implementing the INSERT transfers raw records from
+** tab2 over to tab1.  The columns are not decoded.  Raw records from
+** the indices of tab2 are transfered to tab1 as well.  In so doing,
+** the resulting tab1 has much less fragmentation.
+**
+** This routine returns TRUE if the optimization is attempted.  If any
+** of the conditions above fail so that the optimization should not
+** be attempted, then this routine returns FALSE.
+*/
+static int xferOptimization(
+  Parse *pParse,        /* Parser context */
+  Table *pDest,         /* The table we are inserting into */
+  Select *pSelect,      /* A SELECT statement to use as the data source */
+  int onError,          /* How to handle constraint errors */
+  int iDbDest           /* The database of pDest */
+){
+  ExprList *pEList;                /* The result set of the SELECT */
+  Table *pSrc;                     /* The table in the FROM clause of SELECT */
+  Index *pSrcIdx, *pDestIdx;       /* Source and destination indices */
+  struct SrcList_item *pItem;      /* An element of pSelect->pSrc */
+  int i;                           /* Loop counter */
+  int iDbSrc;                      /* The database of pSrc */
+  int iSrc, iDest;                 /* Cursors from source and destination */
+  int addr1, addr2;                /* Loop addresses */
+  int emptyDestTest;               /* Address of test for empty pDest */
+  int emptySrcTest;                /* Address of test for empty pSrc */
+  Vdbe *v;                         /* The VDBE we are building */
+  KeyInfo *pKey;                   /* Key information for an index */
+  int regAutoinc;                  /* Memory register used by AUTOINC */
+  int destHasUniqueIdx = 0;        /* True if pDest has a UNIQUE index */
+  int regData, regRowid;           /* Registers holding data and rowid */
+
+  if( pSelect==0 ){
+    return 0;   /* Must be of the form  INSERT INTO ... SELECT ... */
+  }
+  if( pDest->pTrigger ){
+    return 0;   /* tab1 must not have triggers */
+  }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if( pDest->isVirtual ){
+    return 0;   /* tab1 must not be a virtual table */
+  }
+#endif
+  if( onError==OE_Default ){
+    onError = OE_Abort;
+  }
+  if( onError!=OE_Abort && onError!=OE_Rollback ){
+    return 0;   /* Cannot do OR REPLACE or OR IGNORE or OR FAIL */
+  }
+  assert(pSelect->pSrc);   /* allocated even if there is no FROM clause */
+  if( pSelect->pSrc->nSrc!=1 ){
+    return 0;   /* FROM clause must have exactly one term */
+  }
+  if( pSelect->pSrc->a[0].pSelect ){
+    return 0;   /* FROM clause cannot contain a subquery */
+  }
+  if( pSelect->pWhere ){
+    return 0;   /* SELECT may not have a WHERE clause */
+  }
+  if( pSelect->pOrderBy ){
+    return 0;   /* SELECT may not have an ORDER BY clause */
+  }
+  /* Do not need to test for a HAVING clause.  If HAVING is present but
+  ** there is no ORDER BY, we will get an error. */
+  if( pSelect->pGroupBy ){
+    return 0;   /* SELECT may not have a GROUP BY clause */
+  }
+  if( pSelect->pLimit ){
+    return 0;   /* SELECT may not have a LIMIT clause */
+  }
+  assert( pSelect->pOffset==0 );  /* Must be so if pLimit==0 */
+  if( pSelect->pPrior ){
+    return 0;   /* SELECT may not be a compound query */
+  }
+  if( pSelect->isDistinct ){
+    return 0;   /* SELECT may not be DISTINCT */
+  }
+  pEList = pSelect->pEList;
+  assert( pEList!=0 );
+  if( pEList->nExpr!=1 ){
+    return 0;   /* The result set must have exactly one column */
+  }
+  assert( pEList->a[0].pExpr );
+  if( pEList->a[0].pExpr->op!=TK_ALL ){
+    return 0;   /* The result set must be the special operator "*" */
+  }
+
+  /* At this point we have established that the statement is of the
+  ** correct syntactic form to participate in this optimization.  Now
+  ** we have to check the semantics.
+  */
+  pItem = pSelect->pSrc->a;
+  pSrc = sqlite3LocateTable(pParse, 0, pItem->zName, pItem->zDatabase);
+  if( pSrc==0 ){
+    return 0;   /* FROM clause does not contain a real table */
+  }
+  if( pSrc==pDest ){
+    return 0;   /* tab1 and tab2 may not be the same table */
+  }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if( pSrc->isVirtual ){
+    return 0;   /* tab2 must not be a virtual table */
+  }
+#endif
+  if( pSrc->pSelect ){
+    return 0;   /* tab2 may not be a view */
+  }
+  if( pDest->nCol!=pSrc->nCol ){
+    return 0;   /* Number of columns must be the same in tab1 and tab2 */
+  }
+  if( pDest->iPKey!=pSrc->iPKey ){
+    return 0;   /* Both tables must have the same INTEGER PRIMARY KEY */
+  }
+  for(i=0; i<pDest->nCol; i++){
+    if( pDest->aCol[i].affinity!=pSrc->aCol[i].affinity ){
+      return 0;    /* Affinity must be the same on all columns */
+    }
+    if( !xferCompatibleCollation(pDest->aCol[i].zColl, pSrc->aCol[i].zColl) ){
+      return 0;    /* Collating sequence must be the same on all columns */
+    }
+    if( pDest->aCol[i].notNull && !pSrc->aCol[i].notNull ){
+      return 0;    /* tab2 must be NOT NULL if tab1 is */
+    }
+  }
+  for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
+    if( pDestIdx->onError!=OE_None ){
+      destHasUniqueIdx = 1;
+    }
+    for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
+      if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
+    }
+    if( pSrcIdx==0 ){
+      return 0;    /* pDestIdx has no corresponding index in pSrc */
+    }
+  }
+#ifndef SQLITE_OMIT_CHECK
+  if( pDest->pCheck && !sqlite3ExprCompare(pSrc->pCheck, pDest->pCheck) ){
+    return 0;   /* Tables have different CHECK constraints.  Ticket #2252 */
+  }
+#endif
+
+  /* If we get this far, it means either:
+  **
+  **    *   We can always do the transfer if the table contains an
+  **        an integer primary key
+  **
+  **    *   We can conditionally do the transfer if the destination
+  **        table is empty.
+  */
+#ifdef SQLITE_TEST
+  sqlite3_xferopt_count++;
+#endif
+  iDbSrc = sqlite3SchemaToIndex(pParse->db, pSrc->pSchema);
+  v = sqlite3GetVdbe(pParse);
+  sqlite3CodeVerifySchema(pParse, iDbSrc);
+  iSrc = pParse->nTab++;
+  iDest = pParse->nTab++;
+  regAutoinc = autoIncBegin(pParse, iDbDest, pDest);
+  sqlite3OpenTable(pParse, iDest, iDbDest, pDest, OP_OpenWrite);
+  if( (pDest->iPKey<0 && pDest->pIndex!=0) || destHasUniqueIdx ){
+    /* If tables do not have an INTEGER PRIMARY KEY and there
+    ** are indices to be copied and the destination is not empty,
+    ** we have to disallow the transfer optimization because the
+    ** the rowids might change which will mess up indexing.
+    **
+    ** Or if the destination has a UNIQUE index and is not empty,
+    ** we also disallow the transfer optimization because we cannot
+    ** insure that all entries in the union of DEST and SRC will be
+    ** unique.
+    */
+    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0);
+    emptyDestTest = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
+    sqlite3VdbeJumpHere(v, addr1);
+  }else{
+    emptyDestTest = 0;
+  }
+  sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
+  emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
+  regData = sqlite3GetTempReg(pParse);
+  regRowid = sqlite3GetTempReg(pParse);
+  if( pDest->iPKey>=0 ){
+    addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
+    addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
+    sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0,
+                      "PRIMARY KEY must be unique", P4_STATIC);
+    sqlite3VdbeJumpHere(v, addr2);
+    autoIncStep(pParse, regAutoinc, regRowid);
+  }else if( pDest->pIndex==0 ){
+    addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
+  }else{
+    addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
+    assert( pDest->autoInc==0 );
+  }
+  sqlite3VdbeAddOp2(v, OP_RowData, iSrc, regData);
+  sqlite3VdbeAddOp3(v, OP_Insert, iDest, regData, regRowid);
+  sqlite3VdbeChangeP5(v, OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND);
+  sqlite3VdbeChangeP4(v, -1, pDest->zName, 0);
+  sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1);
+  autoIncEnd(pParse, iDbDest, pDest, regAutoinc);
+  for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
+    for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
+      if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
+    }
+    assert( pSrcIdx );
+    sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
+    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
+    pKey = sqlite3IndexKeyinfo(pParse, pSrcIdx);
+    sqlite3VdbeAddOp4(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc,
+                      (char*)pKey, P4_KEYINFO_HANDOFF);
+    VdbeComment((v, "%s", pSrcIdx->zName));
+    pKey = sqlite3IndexKeyinfo(pParse, pDestIdx);
+    sqlite3VdbeAddOp4(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest,
+                      (char*)pKey, P4_KEYINFO_HANDOFF);
+    VdbeComment((v, "%s", pDestIdx->zName));
+    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
+    sqlite3VdbeAddOp2(v, OP_RowKey, iSrc, regData);
+    sqlite3VdbeAddOp3(v, OP_IdxInsert, iDest, regData, 1);
+    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1);
+    sqlite3VdbeJumpHere(v, addr1);
+  }
+  sqlite3VdbeJumpHere(v, emptySrcTest);
+  sqlite3ReleaseTempReg(pParse, regRowid);
+  sqlite3ReleaseTempReg(pParse, regData);
+  sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
+  sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
+  if( emptyDestTest ){
+    sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);
+    sqlite3VdbeJumpHere(v, emptyDestTest);
+    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
+    return 0;
+  }else{
+    return 1;
+  }
+}
+#endif /* SQLITE_OMIT_XFER_OPT */
+
+/* Make sure "isView" gets undefined in case this file becomes part of
+** the amalgamation - so that subsequent files do not see isView as a
+** macro. */
+#undef isView
diff --git a/third_party/sqlite/src/journal.c b/third_party/sqlite/src/journal.c
new file mode 100755
index 0000000..bdc36bc
--- /dev/null
+++ b/third_party/sqlite/src/journal.c
@@ -0,0 +1,239 @@
+/*
+** 2007 August 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** @(#) $Id: journal.c,v 1.8 2008/05/01 18:01:47 drh Exp $
+*/
+
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+
+/*
+** This file implements a special kind of sqlite3_file object used
+** by SQLite to create journal files if the atomic-write optimization
+** is enabled.
+**
+** The distinctive characteristic of this sqlite3_file is that the
+** actual on disk file is created lazily. When the file is created,
+** the caller specifies a buffer size for an in-memory buffer to
+** be used to service read() and write() requests. The actual file
+** on disk is not created or populated until either:
+**
+**   1) The in-memory representation grows too large for the allocated 
+**      buffer, or
+**   2) The xSync() method is called.
+*/
+
+#include "sqliteInt.h"
+
+
+/*
+** A JournalFile object is a subclass of sqlite3_file used by
+** as an open file handle for journal files.
+*/
+struct JournalFile {
+  sqlite3_io_methods *pMethod;    /* I/O methods on journal files */
+  int nBuf;                       /* Size of zBuf[] in bytes */
+  char *zBuf;                     /* Space to buffer journal writes */
+  int iSize;                      /* Amount of zBuf[] currently used */
+  int flags;                      /* xOpen flags */
+  sqlite3_vfs *pVfs;              /* The "real" underlying VFS */
+  sqlite3_file *pReal;            /* The "real" underlying file descriptor */
+  const char *zJournal;           /* Name of the journal file */
+};
+typedef struct JournalFile JournalFile;
+
+/*
+** If it does not already exists, create and populate the on-disk file 
+** for JournalFile p.
+*/
+static int createFile(JournalFile *p){
+  int rc = SQLITE_OK;
+  if( !p->pReal ){
+    sqlite3_file *pReal = (sqlite3_file *)&p[1];
+    rc = sqlite3OsOpen(p->pVfs, p->zJournal, pReal, p->flags, 0);
+    if( rc==SQLITE_OK ){
+      p->pReal = pReal;
+      if( p->iSize>0 ){
+        assert(p->iSize<=p->nBuf);
+        rc = sqlite3OsWrite(p->pReal, p->zBuf, p->iSize, 0);
+      }
+    }
+  }
+  return rc;
+}
+
+/*
+** Close the file.
+*/
+static int jrnlClose(sqlite3_file *pJfd){
+  JournalFile *p = (JournalFile *)pJfd;
+  if( p->pReal ){
+    sqlite3OsClose(p->pReal);
+  }
+  sqlite3_free(p->zBuf);
+  return SQLITE_OK;
+}
+
+/*
+** Read data from the file.
+*/
+static int jrnlRead(
+  sqlite3_file *pJfd,    /* The journal file from which to read */
+  void *zBuf,            /* Put the results here */
+  int iAmt,              /* Number of bytes to read */
+  sqlite_int64 iOfst     /* Begin reading at this offset */
+){
+  int rc = SQLITE_OK;
+  JournalFile *p = (JournalFile *)pJfd;
+  if( p->pReal ){
+    rc = sqlite3OsRead(p->pReal, zBuf, iAmt, iOfst);
+  }else{
+    assert( iAmt+iOfst<=p->iSize );
+    memcpy(zBuf, &p->zBuf[iOfst], iAmt);
+  }
+  return rc;
+}
+
+/*
+** Write data to the file.
+*/
+static int jrnlWrite(
+  sqlite3_file *pJfd,    /* The journal file into which to write */
+  const void *zBuf,      /* Take data to be written from here */
+  int iAmt,              /* Number of bytes to write */
+  sqlite_int64 iOfst     /* Begin writing at this offset into the file */
+){
+  int rc = SQLITE_OK;
+  JournalFile *p = (JournalFile *)pJfd;
+  if( !p->pReal && (iOfst+iAmt)>p->nBuf ){
+    rc = createFile(p);
+  }
+  if( rc==SQLITE_OK ){
+    if( p->pReal ){
+      rc = sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
+    }else{
+      memcpy(&p->zBuf[iOfst], zBuf, iAmt);
+      if( p->iSize<(iOfst+iAmt) ){
+        p->iSize = (iOfst+iAmt);
+      }
+    }
+  }
+  return rc;
+}
+
+/*
+** Truncate the file.
+*/
+static int jrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){
+  int rc = SQLITE_OK;
+  JournalFile *p = (JournalFile *)pJfd;
+  if( p->pReal ){
+    rc = sqlite3OsTruncate(p->pReal, size);
+  }else if( size<p->iSize ){
+    p->iSize = size;
+  }
+  return rc;
+}
+
+/*
+** Sync the file.
+*/
+static int jrnlSync(sqlite3_file *pJfd, int flags){
+  int rc;
+  JournalFile *p = (JournalFile *)pJfd;
+  if( p->pReal ){
+    rc = sqlite3OsSync(p->pReal, flags);
+  }else{
+    rc = SQLITE_OK;
+  }
+  return rc;
+}
+
+/*
+** Query the size of the file in bytes.
+*/
+static int jrnlFileSize(sqlite3_file *pJfd, sqlite_int64 *pSize){
+  int rc = SQLITE_OK;
+  JournalFile *p = (JournalFile *)pJfd;
+  if( p->pReal ){
+    rc = sqlite3OsFileSize(p->pReal, pSize);
+  }else{
+    *pSize = (sqlite_int64) p->iSize;
+  }
+  return rc;
+}
+
+/*
+** Table of methods for JournalFile sqlite3_file object.
+*/
+static struct sqlite3_io_methods JournalFileMethods = {
+  1,             /* iVersion */
+  jrnlClose,     /* xClose */
+  jrnlRead,      /* xRead */
+  jrnlWrite,     /* xWrite */
+  jrnlTruncate,  /* xTruncate */
+  jrnlSync,      /* xSync */
+  jrnlFileSize,  /* xFileSize */
+  0,             /* xLock */
+  0,             /* xUnlock */
+  0,             /* xCheckReservedLock */
+  0,             /* xFileControl */
+  0,             /* xSectorSize */
+  0              /* xDeviceCharacteristics */
+};
+
+/* 
+** Open a journal file.
+*/
+int sqlite3JournalOpen(
+  sqlite3_vfs *pVfs,         /* The VFS to use for actual file I/O */
+  const char *zName,         /* Name of the journal file */
+  sqlite3_file *pJfd,        /* Preallocated, blank file handle */
+  int flags,                 /* Opening flags */
+  int nBuf                   /* Bytes buffered before opening the file */
+){
+  JournalFile *p = (JournalFile *)pJfd;
+  memset(p, 0, sqlite3JournalSize(pVfs));
+  if( nBuf>0 ){
+    p->zBuf = sqlite3MallocZero(nBuf);
+    if( !p->zBuf ){
+      return SQLITE_NOMEM;
+    }
+  }else{
+    return sqlite3OsOpen(pVfs, zName, pJfd, flags, 0);
+  }
+  p->pMethod = &JournalFileMethods;
+  p->nBuf = nBuf;
+  p->flags = flags;
+  p->zJournal = zName;
+  p->pVfs = pVfs;
+  return SQLITE_OK;
+}
+
+/*
+** If the argument p points to a JournalFile structure, and the underlying
+** file has not yet been created, create it now.
+*/
+int sqlite3JournalCreate(sqlite3_file *p){
+  if( p->pMethods!=&JournalFileMethods ){
+    return SQLITE_OK;
+  }
+  return createFile((JournalFile *)p);
+}
+
+/* 
+** Return the number of bytes required to store a JournalFile that uses vfs
+** pVfs to create the underlying on-disk files.
+*/
+int sqlite3JournalSize(sqlite3_vfs *pVfs){
+  return (pVfs->szOsFile+sizeof(JournalFile));
+}
+#endif
diff --git a/third_party/sqlite/src/legacy.c b/third_party/sqlite/src/legacy.c
new file mode 100755
index 0000000..e6b75c0
--- /dev/null
+++ b/third_party/sqlite/src/legacy.c
@@ -0,0 +1,146 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Main file for the SQLite library.  The routines in this file
+** implement the programmer interface to the library.  Routines in
+** other files are for internal use by SQLite and should not be
+** accessed by users of the library.
+**
+** $Id: legacy.c,v 1.29 2008/08/02 03:50:39 drh Exp $
+*/
+
+#include "sqliteInt.h"
+#include <ctype.h>
+
+/*
+** Execute SQL code.  Return one of the SQLITE_ success/failure
+** codes.  Also write an error message into memory obtained from
+** malloc() and make *pzErrMsg point to that message.
+**
+** If the SQL is a query, then for each row in the query result
+** the xCallback() function is called.  pArg becomes the first
+** argument to xCallback().  If xCallback=NULL then no callback
+** is invoked, even for queries.
+*/
+int sqlite3_exec(
+  sqlite3 *db,                /* The database on which the SQL executes */
+  const char *zSql,           /* The SQL to be executed */
+  sqlite3_callback xCallback, /* Invoke this callback routine */
+  void *pArg,                 /* First argument to xCallback() */
+  char **pzErrMsg             /* Write error messages here */
+){
+  int rc = SQLITE_OK;
+  const char *zLeftover;
+  sqlite3_stmt *pStmt = 0;
+  char **azCols = 0;
+
+  int nRetry = 0;
+  int nCallback;
+
+  if( zSql==0 ) zSql = "";
+
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3Error(db, SQLITE_OK, 0);
+  while( (rc==SQLITE_OK || (rc==SQLITE_SCHEMA && (++nRetry)<2)) && zSql[0] ){
+    int nCol;
+    char **azVals = 0;
+
+    pStmt = 0;
+    rc = sqlite3_prepare(db, zSql, -1, &pStmt, &zLeftover);
+    assert( rc==SQLITE_OK || pStmt==0 );
+    if( rc!=SQLITE_OK ){
+      continue;
+    }
+    if( !pStmt ){
+      /* this happens for a comment or white-space */
+      zSql = zLeftover;
+      continue;
+    }
+
+    nCallback = 0;
+    nCol = sqlite3_column_count(pStmt);
+
+    while( 1 ){
+      int i;
+      rc = sqlite3_step(pStmt);
+
+      /* Invoke the callback function if required */
+      if( xCallback && (SQLITE_ROW==rc || 
+          (SQLITE_DONE==rc && !nCallback && db->flags&SQLITE_NullCallback)) ){
+        if( 0==nCallback ){
+          if( azCols==0 ){
+            azCols = sqlite3DbMallocZero(db, 2*nCol*sizeof(const char*) + 1);
+            if( azCols==0 ){
+              goto exec_out;
+            }
+          }
+          for(i=0; i<nCol; i++){
+            azCols[i] = (char *)sqlite3_column_name(pStmt, i);
+            /* sqlite3VdbeSetColName() installs column names as UTF8
+            ** strings so there is no way for sqlite3_column_name() to fail. */
+            assert( azCols[i]!=0 );
+          }
+          nCallback++;
+        }
+        if( rc==SQLITE_ROW ){
+          azVals = &azCols[nCol];
+          for(i=0; i<nCol; i++){
+            azVals[i] = (char *)sqlite3_column_text(pStmt, i);
+            if( !azVals[i] && sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){
+              db->mallocFailed = 1;
+              goto exec_out;
+            }
+          }
+        }
+        if( xCallback(pArg, nCol, azVals, azCols) ){
+          rc = SQLITE_ABORT;
+          sqlite3_finalize(pStmt);
+          pStmt = 0;
+          sqlite3Error(db, SQLITE_ABORT, 0);
+          goto exec_out;
+        }
+      }
+
+      if( rc!=SQLITE_ROW ){
+        rc = sqlite3_finalize(pStmt);
+        pStmt = 0;
+        if( rc!=SQLITE_SCHEMA ){
+          nRetry = 0;
+          zSql = zLeftover;
+          while( isspace((unsigned char)zSql[0]) ) zSql++;
+        }
+        break;
+      }
+    }
+
+    sqlite3DbFree(db, azCols);
+    azCols = 0;
+  }
+
+exec_out:
+  if( pStmt ) sqlite3_finalize(pStmt);
+  sqlite3DbFree(db, azCols);
+
+  rc = sqlite3ApiExit(db, rc);
+  if( rc!=SQLITE_OK && rc==sqlite3_errcode(db) && pzErrMsg ){
+    int nErrMsg = 1 + strlen(sqlite3_errmsg(db));
+    *pzErrMsg = sqlite3Malloc(nErrMsg);
+    if( *pzErrMsg ){
+      memcpy(*pzErrMsg, sqlite3_errmsg(db), nErrMsg);
+    }
+  }else if( pzErrMsg ){
+    *pzErrMsg = 0;
+  }
+
+  assert( (rc&db->errMask)==rc );
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
diff --git a/third_party/sqlite/src/loadext.c b/third_party/sqlite/src/loadext.c
new file mode 100755
index 0000000..2f7ca52
--- /dev/null
+++ b/third_party/sqlite/src/loadext.c
@@ -0,0 +1,569 @@
+/*
+** 2006 June 7
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code used to dynamically load extensions into
+** the SQLite library.
+**
+** $Id: loadext.c,v 1.53 2008/08/02 03:50:39 drh Exp $
+*/
+
+#ifndef SQLITE_CORE
+  #define SQLITE_CORE 1  /* Disable the API redefinition in sqlite3ext.h */
+#endif
+#include "sqlite3ext.h"
+#include "sqliteInt.h"
+#include <string.h>
+#include <ctype.h>
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+
+/*
+** Some API routines are omitted when various features are
+** excluded from a build of SQLite.  Substitute a NULL pointer
+** for any missing APIs.
+*/
+#ifndef SQLITE_ENABLE_COLUMN_METADATA
+# define sqlite3_column_database_name   0
+# define sqlite3_column_database_name16 0
+# define sqlite3_column_table_name      0
+# define sqlite3_column_table_name16    0
+# define sqlite3_column_origin_name     0
+# define sqlite3_column_origin_name16   0
+# define sqlite3_table_column_metadata  0
+#endif
+
+#ifdef SQLITE_OMIT_AUTHORIZATION
+# define sqlite3_set_authorizer         0
+#endif
+
+#ifdef SQLITE_OMIT_UTF16
+# define sqlite3_bind_text16            0
+# define sqlite3_collation_needed16     0
+# define sqlite3_column_decltype16      0
+# define sqlite3_column_name16          0
+# define sqlite3_column_text16          0
+# define sqlite3_complete16             0
+# define sqlite3_create_collation16     0
+# define sqlite3_create_function16      0
+# define sqlite3_errmsg16               0
+# define sqlite3_open16                 0
+# define sqlite3_prepare16              0
+# define sqlite3_prepare16_v2           0
+# define sqlite3_result_error16         0
+# define sqlite3_result_text16          0
+# define sqlite3_result_text16be        0
+# define sqlite3_result_text16le        0
+# define sqlite3_value_text16           0
+# define sqlite3_value_text16be         0
+# define sqlite3_value_text16le         0
+# define sqlite3_column_database_name16 0
+# define sqlite3_column_table_name16    0
+# define sqlite3_column_origin_name16   0
+#endif
+
+#ifdef SQLITE_OMIT_COMPLETE
+# define sqlite3_complete 0
+# define sqlite3_complete16 0
+#endif
+
+#ifdef SQLITE_OMIT_PROGRESS_CALLBACK
+# define sqlite3_progress_handler 0
+#endif
+
+#ifdef SQLITE_OMIT_VIRTUALTABLE
+# define sqlite3_create_module 0
+# define sqlite3_create_module_v2 0
+# define sqlite3_declare_vtab 0
+#endif
+
+#ifdef SQLITE_OMIT_SHARED_CACHE
+# define sqlite3_enable_shared_cache 0
+#endif
+
+#ifdef SQLITE_OMIT_TRACE
+# define sqlite3_profile       0
+# define sqlite3_trace         0
+#endif
+
+#ifdef SQLITE_OMIT_GET_TABLE
+# define sqlite3_free_table    0
+# define sqlite3_get_table     0
+#endif
+
+#ifdef SQLITE_OMIT_INCRBLOB
+#define sqlite3_bind_zeroblob  0
+#define sqlite3_blob_bytes     0
+#define sqlite3_blob_close     0
+#define sqlite3_blob_open      0
+#define sqlite3_blob_read      0
+#define sqlite3_blob_write     0
+#endif
+
+/*
+** The following structure contains pointers to all SQLite API routines.
+** A pointer to this structure is passed into extensions when they are
+** loaded so that the extension can make calls back into the SQLite
+** library.
+**
+** When adding new APIs, add them to the bottom of this structure
+** in order to preserve backwards compatibility.
+**
+** Extensions that use newer APIs should first call the
+** sqlite3_libversion_number() to make sure that the API they
+** intend to use is supported by the library.  Extensions should
+** also check to make sure that the pointer to the function is
+** not NULL before calling it.
+*/
+static const sqlite3_api_routines sqlite3Apis = {
+  sqlite3_aggregate_context,
+  sqlite3_aggregate_count,
+  sqlite3_bind_blob,
+  sqlite3_bind_double,
+  sqlite3_bind_int,
+  sqlite3_bind_int64,
+  sqlite3_bind_null,
+  sqlite3_bind_parameter_count,
+  sqlite3_bind_parameter_index,
+  sqlite3_bind_parameter_name,
+  sqlite3_bind_text,
+  sqlite3_bind_text16,
+  sqlite3_bind_value,
+  sqlite3_busy_handler,
+  sqlite3_busy_timeout,
+  sqlite3_changes,
+  sqlite3_close,
+  sqlite3_collation_needed,
+  sqlite3_collation_needed16,
+  sqlite3_column_blob,
+  sqlite3_column_bytes,
+  sqlite3_column_bytes16,
+  sqlite3_column_count,
+  sqlite3_column_database_name,
+  sqlite3_column_database_name16,
+  sqlite3_column_decltype,
+  sqlite3_column_decltype16,
+  sqlite3_column_double,
+  sqlite3_column_int,
+  sqlite3_column_int64,
+  sqlite3_column_name,
+  sqlite3_column_name16,
+  sqlite3_column_origin_name,
+  sqlite3_column_origin_name16,
+  sqlite3_column_table_name,
+  sqlite3_column_table_name16,
+  sqlite3_column_text,
+  sqlite3_column_text16,
+  sqlite3_column_type,
+  sqlite3_column_value,
+  sqlite3_commit_hook,
+  sqlite3_complete,
+  sqlite3_complete16,
+  sqlite3_create_collation,
+  sqlite3_create_collation16,
+  sqlite3_create_function,
+  sqlite3_create_function16,
+  sqlite3_create_module,
+  sqlite3_data_count,
+  sqlite3_db_handle,
+  sqlite3_declare_vtab,
+  sqlite3_enable_shared_cache,
+  sqlite3_errcode,
+  sqlite3_errmsg,
+  sqlite3_errmsg16,
+  sqlite3_exec,
+  sqlite3_expired,
+  sqlite3_finalize,
+  sqlite3_free,
+  sqlite3_free_table,
+  sqlite3_get_autocommit,
+  sqlite3_get_auxdata,
+  sqlite3_get_table,
+  0,     /* Was sqlite3_global_recover(), but that function is deprecated */
+  sqlite3_interrupt,
+  sqlite3_last_insert_rowid,
+  sqlite3_libversion,
+  sqlite3_libversion_number,
+  sqlite3_malloc,
+  sqlite3_mprintf,
+  sqlite3_open,
+  sqlite3_open16,
+  sqlite3_prepare,
+  sqlite3_prepare16,
+  sqlite3_profile,
+  sqlite3_progress_handler,
+  sqlite3_realloc,
+  sqlite3_reset,
+  sqlite3_result_blob,
+  sqlite3_result_double,
+  sqlite3_result_error,
+  sqlite3_result_error16,
+  sqlite3_result_int,
+  sqlite3_result_int64,
+  sqlite3_result_null,
+  sqlite3_result_text,
+  sqlite3_result_text16,
+  sqlite3_result_text16be,
+  sqlite3_result_text16le,
+  sqlite3_result_value,
+  sqlite3_rollback_hook,
+  sqlite3_set_authorizer,
+  sqlite3_set_auxdata,
+  sqlite3_snprintf,
+  sqlite3_step,
+  sqlite3_table_column_metadata,
+  sqlite3_thread_cleanup,
+  sqlite3_total_changes,
+  sqlite3_trace,
+  sqlite3_transfer_bindings,
+  sqlite3_update_hook,
+  sqlite3_user_data,
+  sqlite3_value_blob,
+  sqlite3_value_bytes,
+  sqlite3_value_bytes16,
+  sqlite3_value_double,
+  sqlite3_value_int,
+  sqlite3_value_int64,
+  sqlite3_value_numeric_type,
+  sqlite3_value_text,
+  sqlite3_value_text16,
+  sqlite3_value_text16be,
+  sqlite3_value_text16le,
+  sqlite3_value_type,
+  sqlite3_vmprintf,
+  /*
+  ** The original API set ends here.  All extensions can call any
+  ** of the APIs above provided that the pointer is not NULL.  But
+  ** before calling APIs that follow, extension should check the
+  ** sqlite3_libversion_number() to make sure they are dealing with
+  ** a library that is new enough to support that API.
+  *************************************************************************
+  */
+  sqlite3_overload_function,
+
+  /*
+  ** Added after 3.3.13
+  */
+  sqlite3_prepare_v2,
+  sqlite3_prepare16_v2,
+  sqlite3_clear_bindings,
+
+  /*
+  ** Added for 3.4.1
+  */
+  sqlite3_create_module_v2,
+
+  /*
+  ** Added for 3.5.0
+  */
+  sqlite3_bind_zeroblob,
+  sqlite3_blob_bytes,
+  sqlite3_blob_close,
+  sqlite3_blob_open,
+  sqlite3_blob_read,
+  sqlite3_blob_write,
+  sqlite3_create_collation_v2,
+  sqlite3_file_control,
+  sqlite3_memory_highwater,
+  sqlite3_memory_used,
+#ifdef SQLITE_MUTEX_NOOP
+  0, 
+  0, 
+  0,
+  0,
+  0,
+#else
+  sqlite3_mutex_alloc,
+  sqlite3_mutex_enter,
+  sqlite3_mutex_free,
+  sqlite3_mutex_leave,
+  sqlite3_mutex_try,
+#endif
+  sqlite3_open_v2,
+  sqlite3_release_memory,
+  sqlite3_result_error_nomem,
+  sqlite3_result_error_toobig,
+  sqlite3_sleep,
+  sqlite3_soft_heap_limit,
+  sqlite3_vfs_find,
+  sqlite3_vfs_register,
+  sqlite3_vfs_unregister,
+
+  /*
+  ** Added for 3.5.8
+  */
+  sqlite3_threadsafe,
+  sqlite3_result_zeroblob,
+  sqlite3_result_error_code,
+  sqlite3_test_control,
+  sqlite3_randomness,
+  sqlite3_context_db_handle,
+
+  /*
+  ** Added for 3.6.0
+  */
+  sqlite3_extended_result_codes,
+  sqlite3_limit,
+  sqlite3_next_stmt,
+  sqlite3_sql,
+  sqlite3_status,
+};
+
+/*
+** Attempt to load an SQLite extension library contained in the file
+** zFile.  The entry point is zProc.  zProc may be 0 in which case a
+** default entry point name (sqlite3_extension_init) is used.  Use
+** of the default name is recommended.
+**
+** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
+**
+** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with 
+** error message text.  The calling function should free this memory
+** by calling sqlite3DbFree(db, ).
+*/
+static int sqlite3LoadExtension(
+  sqlite3 *db,          /* Load the extension into this database connection */
+  const char *zFile,    /* Name of the shared library containing extension */
+  const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
+  char **pzErrMsg       /* Put error message here if not 0 */
+){
+  sqlite3_vfs *pVfs = db->pVfs;
+  void *handle;
+  int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
+  char *zErrmsg = 0;
+  void **aHandle;
+
+  /* Ticket #1863.  To avoid a creating security problems for older
+  ** applications that relink against newer versions of SQLite, the
+  ** ability to run load_extension is turned off by default.  One
+  ** must call sqlite3_enable_load_extension() to turn on extension
+  ** loading.  Otherwise you get the following error.
+  */
+  if( (db->flags & SQLITE_LoadExtension)==0 ){
+    if( pzErrMsg ){
+      *pzErrMsg = sqlite3_mprintf("not authorized");
+    }
+    return SQLITE_ERROR;
+  }
+
+  if( zProc==0 ){
+    zProc = "sqlite3_extension_init";
+  }
+
+  handle = sqlite3OsDlOpen(pVfs, zFile);
+  if( handle==0 ){
+    if( pzErrMsg ){
+      char zErr[256];
+      zErr[sizeof(zErr)-1] = '\0';
+      sqlite3_snprintf(sizeof(zErr)-1, zErr, 
+          "unable to open shared library [%s]", zFile);
+      sqlite3OsDlError(pVfs, sizeof(zErr)-1, zErr);
+      *pzErrMsg = sqlite3DbStrDup(0, zErr);
+    }
+    return SQLITE_ERROR;
+  }
+  xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
+                   sqlite3OsDlSym(pVfs, handle, zProc);
+  if( xInit==0 ){
+    if( pzErrMsg ){
+      char zErr[256];
+      zErr[sizeof(zErr)-1] = '\0';
+      sqlite3_snprintf(sizeof(zErr)-1, zErr,
+          "no entry point [%s] in shared library [%s]", zProc,zFile);
+      sqlite3OsDlError(pVfs, sizeof(zErr)-1, zErr);
+      *pzErrMsg = sqlite3DbStrDup(0, zErr);
+      sqlite3OsDlClose(pVfs, handle);
+    }
+    return SQLITE_ERROR;
+  }else if( xInit(db, &zErrmsg, &sqlite3Apis) ){
+    if( pzErrMsg ){
+      *pzErrMsg = sqlite3_mprintf("error during initialization: %s", zErrmsg);
+    }
+    sqlite3_free(zErrmsg);
+    sqlite3OsDlClose(pVfs, handle);
+    return SQLITE_ERROR;
+  }
+
+  /* Append the new shared library handle to the db->aExtension array. */
+  aHandle = sqlite3DbMallocZero(db, sizeof(handle)*(db->nExtension+1));
+  if( aHandle==0 ){
+    return SQLITE_NOMEM;
+  }
+  if( db->nExtension>0 ){
+    memcpy(aHandle, db->aExtension, sizeof(handle)*db->nExtension);
+  }
+  sqlite3DbFree(db, db->aExtension);
+  db->aExtension = aHandle;
+
+  db->aExtension[db->nExtension++] = handle;
+  return SQLITE_OK;
+}
+int sqlite3_load_extension(
+  sqlite3 *db,          /* Load the extension into this database connection */
+  const char *zFile,    /* Name of the shared library containing extension */
+  const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
+  char **pzErrMsg       /* Put error message here if not 0 */
+){
+  int rc;
+  sqlite3_mutex_enter(db->mutex);
+  rc = sqlite3LoadExtension(db, zFile, zProc, pzErrMsg);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Call this routine when the database connection is closing in order
+** to clean up loaded extensions
+*/
+void sqlite3CloseExtensions(sqlite3 *db){
+  int i;
+  assert( sqlite3_mutex_held(db->mutex) );
+  for(i=0; i<db->nExtension; i++){
+    sqlite3OsDlClose(db->pVfs, db->aExtension[i]);
+  }
+  sqlite3DbFree(db, db->aExtension);
+}
+
+/*
+** Enable or disable extension loading.  Extension loading is disabled by
+** default so as not to open security holes in older applications.
+*/
+int sqlite3_enable_load_extension(sqlite3 *db, int onoff){
+  sqlite3_mutex_enter(db->mutex);
+  if( onoff ){
+    db->flags |= SQLITE_LoadExtension;
+  }else{
+    db->flags &= ~SQLITE_LoadExtension;
+  }
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+#endif /* SQLITE_OMIT_LOAD_EXTENSION */
+
+/*
+** The auto-extension code added regardless of whether or not extension
+** loading is supported.  We need a dummy sqlite3Apis pointer for that
+** code if regular extension loading is not available.  This is that
+** dummy pointer.
+*/
+#ifdef SQLITE_OMIT_LOAD_EXTENSION
+static const sqlite3_api_routines sqlite3Apis = { 0 };
+#endif
+
+
+/*
+** The following object holds the list of automatically loaded
+** extensions.
+**
+** This list is shared across threads.  The SQLITE_MUTEX_STATIC_MASTER
+** mutex must be held while accessing this list.
+*/
+static struct {
+  int nExt;        /* Number of entries in aExt[] */          
+  void **aExt;     /* Pointers to the extension init functions */
+} autoext = { 0, 0 };
+
+
+/*
+** Register a statically linked extension that is automatically
+** loaded by every new database connection.
+*/
+int sqlite3_auto_extension(void *xInit){
+  int rc = SQLITE_OK;
+#ifndef SQLITE_OMIT_AUTOINIT
+  rc = sqlite3_initialize();
+  if( rc ){
+    return rc;
+  }else
+#endif
+  {
+    int i;
+#ifndef SQLITE_MUTEX_NOOP
+    sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+#endif
+    sqlite3_mutex_enter(mutex);
+    for(i=0; i<autoext.nExt; i++){
+      if( autoext.aExt[i]==xInit ) break;
+    }
+    if( i==autoext.nExt ){
+      int nByte = (autoext.nExt+1)*sizeof(autoext.aExt[0]);
+      void **aNew;
+      aNew = sqlite3_realloc(autoext.aExt, nByte);
+      if( aNew==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        autoext.aExt = aNew;
+        autoext.aExt[autoext.nExt] = xInit;
+        autoext.nExt++;
+      }
+    }
+    sqlite3_mutex_leave(mutex);
+    assert( (rc&0xff)==rc );
+    return rc;
+  }
+}
+
+/*
+** Reset the automatic extension loading mechanism.
+*/
+void sqlite3_reset_auto_extension(void){
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize()==SQLITE_OK )
+#endif
+  {
+#ifndef SQLITE_MUTEX_NOOP
+    sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+#endif
+    sqlite3_mutex_enter(mutex);
+    sqlite3_free(autoext.aExt);
+    autoext.aExt = 0;
+    autoext.nExt = 0;
+    sqlite3_mutex_leave(mutex);
+  }
+}
+
+/*
+** Load all automatic extensions.
+*/
+int sqlite3AutoLoadExtensions(sqlite3 *db){
+  int i;
+  int go = 1;
+  int rc = SQLITE_OK;
+  int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
+
+  if( autoext.nExt==0 ){
+    /* Common case: early out without every having to acquire a mutex */
+    return SQLITE_OK;
+  }
+  for(i=0; go; i++){
+    char *zErrmsg = 0;
+#ifndef SQLITE_MUTEX_NOOP
+    sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+#endif
+    sqlite3_mutex_enter(mutex);
+    if( i>=autoext.nExt ){
+      xInit = 0;
+      go = 0;
+    }else{
+      xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
+              autoext.aExt[i];
+    }
+    sqlite3_mutex_leave(mutex);
+    if( xInit && xInit(db, &zErrmsg, &sqlite3Apis) ){
+      sqlite3Error(db, SQLITE_ERROR,
+            "automatic extension loading failed: %s", zErrmsg);
+      go = 0;
+      rc = SQLITE_ERROR;
+      sqlite3_free(zErrmsg);
+    }
+  }
+  return rc;
+}
diff --git a/third_party/sqlite/src/main.c b/third_party/sqlite/src/main.c
new file mode 100755
index 0000000..68500eb
--- /dev/null
+++ b/third_party/sqlite/src/main.c
@@ -0,0 +1,2005 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Main file for the SQLite library.  The routines in this file
+** implement the programmer interface to the library.  Routines in
+** other files are for internal use by SQLite and should not be
+** accessed by users of the library.
+**
+** $Id: main.c,v 1.486 2008/08/04 20:13:27 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+
+#ifdef SQLITE_ENABLE_FTS3
+# include "fts3.h"
+#endif
+#ifdef SQLITE_ENABLE_RTREE
+# include "rtree.h"
+#endif
+
+/*
+** The version of the library
+*/
+const char sqlite3_version[] = SQLITE_VERSION;
+const char *sqlite3_libversion(void){ return sqlite3_version; }
+int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
+int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
+
+#if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
+/*
+** If the following function pointer is not NULL and if
+** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
+** I/O active are written using this function.  These messages
+** are intended for debugging activity only.
+*/
+void (*sqlite3IoTrace)(const char*, ...) = 0;
+#endif
+
+/*
+** If the following global variable points to a string which is the
+** name of a directory, then that directory will be used to store
+** temporary files.
+**
+** See also the "PRAGMA temp_store_directory" SQL command.
+*/
+char *sqlite3_temp_directory = 0;
+
+/*
+** Initialize SQLite.  
+**
+** This routine must be called to initialize the memory allocation,
+** VFS, and mutex subsystesms prior to doing any serious work with
+** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
+** this routine will be called automatically by key routines such as
+** sqlite3_open().  
+**
+** This routine is a no-op except on its very first call for the process,
+** or for the first call after a call to sqlite3_shutdown.
+*/
+int sqlite3_initialize(void){
+  static int inProgress = 0;
+  int rc;
+
+  /* If SQLite is already initialized, this call is a no-op. */
+  if( sqlite3Config.isInit ) return SQLITE_OK;
+
+  /* Make sure the mutex system is initialized. */
+  rc = sqlite3MutexInit();
+
+  if( rc==SQLITE_OK ){
+
+    /* Initialize the malloc() system and the recursive pInitMutex mutex.
+    ** This operation is protected by the STATIC_MASTER mutex.
+    */
+    sqlite3_mutex *pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+    sqlite3_mutex_enter(pMaster);
+    if( !sqlite3Config.isMallocInit ){
+      rc = sqlite3MallocInit();
+    }
+    if( rc==SQLITE_OK ){
+      sqlite3Config.isMallocInit = 1;
+      if( !sqlite3Config.pInitMutex ){
+        sqlite3Config.pInitMutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
+        if( sqlite3Config.bCoreMutex && !sqlite3Config.pInitMutex ){
+          rc = SQLITE_NOMEM;
+        }
+      }
+    }
+    sqlite3_mutex_leave(pMaster);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+
+    /* Enter the recursive pInitMutex mutex. After doing so, if the
+    ** sqlite3Config.isInit flag is true, then some other thread has
+    ** finished doing the initialization. If the inProgress flag is
+    ** true, then this function is being called recursively from within
+    ** the sqlite3_os_init() call below. In either case, exit early.
+    */
+    sqlite3_mutex_enter(sqlite3Config.pInitMutex);
+    if( sqlite3Config.isInit || inProgress ){
+      sqlite3_mutex_leave(sqlite3Config.pInitMutex);
+      return SQLITE_OK;
+    }
+    sqlite3StatusReset();
+    inProgress = 1;
+    rc = sqlite3_os_init();
+    inProgress = 0;
+    sqlite3Config.isInit = (rc==SQLITE_OK ? 1 : 0);
+    sqlite3_mutex_leave(sqlite3Config.pInitMutex);
+  }
+
+  /* Check NaN support. */
+#ifndef NDEBUG
+  /* This section of code's only "output" is via assert() statements. */
+  if ( rc==SQLITE_OK ){
+    u64 x = (((u64)1)<<63)-1;
+    double y;
+    assert(sizeof(x)==8);
+    assert(sizeof(x)==sizeof(y));
+    memcpy(&y, &x, 8);
+    assert( sqlite3IsNaN(y) );
+  }
+#endif
+
+  return rc;
+}
+
+/*
+** Undo the effects of sqlite3_initialize().  Must not be called while
+** there are outstanding database connections or memory allocations or
+** while any part of SQLite is otherwise in use in any thread.  This
+** routine is not threadsafe.  Not by a long shot.
+*/
+int sqlite3_shutdown(void){
+  sqlite3_mutex_free(sqlite3Config.pInitMutex);
+  sqlite3Config.pInitMutex = 0;
+  sqlite3Config.isMallocInit = 0;
+  if( sqlite3Config.isInit ){
+    sqlite3_os_end();
+  }
+  if( sqlite3Config.m.xShutdown ){
+    sqlite3MallocEnd();
+  }
+  if( sqlite3Config.mutex.xMutexEnd ){
+    sqlite3MutexEnd();
+  }
+  sqlite3Config.isInit = 0;
+  return SQLITE_OK;
+}
+
+/*
+** This API allows applications to modify the global configuration of
+** the SQLite library at run-time.
+**
+** This routine should only be called when there are no outstanding
+** database connections or memory allocations.  This routine is not
+** threadsafe.  Failure to heed these warnings can lead to unpredictable
+** behavior.
+*/
+int sqlite3_config(int op, ...){
+  va_list ap;
+  int rc = SQLITE_OK;
+
+  /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
+  ** the SQLite library is in use. */
+  if( sqlite3Config.isInit ) return SQLITE_MISUSE;
+
+  va_start(ap, op);
+  switch( op ){
+    case SQLITE_CONFIG_SINGLETHREAD: {
+      /* Disable all mutexing */
+      sqlite3Config.bCoreMutex = 0;
+      sqlite3Config.bFullMutex = 0;
+      break;
+    }
+    case SQLITE_CONFIG_MULTITHREAD: {
+      /* Disable mutexing of database connections */
+      /* Enable mutexing of core data structures */
+      sqlite3Config.bCoreMutex = 1;
+      sqlite3Config.bFullMutex = 0;
+      break;
+    }
+    case SQLITE_CONFIG_SERIALIZED: {
+      /* Enable all mutexing */
+      sqlite3Config.bCoreMutex = 1;
+      sqlite3Config.bFullMutex = 1;
+      break;
+    }
+    case SQLITE_CONFIG_MALLOC: {
+      /* Specify an alternative malloc implementation */
+      sqlite3Config.m = *va_arg(ap, sqlite3_mem_methods*);
+      break;
+    }
+    case SQLITE_CONFIG_GETMALLOC: {
+      /* Retrieve the current malloc() implementation */
+      if( sqlite3Config.m.xMalloc==0 ) sqlite3MemSetDefault();
+      *va_arg(ap, sqlite3_mem_methods*) = sqlite3Config.m;
+      break;
+    }
+    case SQLITE_CONFIG_MUTEX: {
+      /* Specify an alternative mutex implementation */
+      sqlite3Config.mutex = *va_arg(ap, sqlite3_mutex_methods*);
+      break;
+    }
+    case SQLITE_CONFIG_GETMUTEX: {
+      /* Retrieve the current mutex implementation */
+      *va_arg(ap, sqlite3_mutex_methods*) = sqlite3Config.mutex;
+      break;
+    }
+    case SQLITE_CONFIG_MEMSTATUS: {
+      /* Enable or disable the malloc status collection */
+      sqlite3Config.bMemstat = va_arg(ap, int);
+      break;
+    }
+    case SQLITE_CONFIG_SCRATCH: {
+      /* Designate a buffer for scratch memory space */
+      sqlite3Config.pScratch = va_arg(ap, void*);
+      sqlite3Config.szScratch = va_arg(ap, int);
+      sqlite3Config.nScratch = va_arg(ap, int);
+      break;
+    }
+    case SQLITE_CONFIG_PAGECACHE: {
+      /* Designate a buffer for scratch memory space */
+      sqlite3Config.pPage = va_arg(ap, void*);
+      sqlite3Config.szPage = va_arg(ap, int);
+      sqlite3Config.nPage = va_arg(ap, int);
+      break;
+    }
+
+#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
+    case SQLITE_CONFIG_HEAP: {
+      /* Designate a buffer for heap memory space */
+      sqlite3Config.pHeap = va_arg(ap, void*);
+      sqlite3Config.nHeap = va_arg(ap, int);
+      sqlite3Config.mnReq = va_arg(ap, int);
+
+      if( sqlite3Config.pHeap==0 ){
+        /* If the heap pointer is NULL, then restore the malloc implementation
+        ** back to NULL pointers too.  This will cause the malloc to go
+        ** back to its default implementation when sqlite3_initialize() is
+        ** run.
+        */
+        memset(&sqlite3Config.m, 0, sizeof(sqlite3Config.m));
+      }else{
+        /* The heap pointer is not NULL, then install one of the
+        ** mem5.c/mem3.c methods. If neither ENABLE_MEMSYS3 nor
+        ** ENABLE_MEMSYS5 is defined, return an error.
+        ** the default case and return an error.
+        */
+#ifdef SQLITE_ENABLE_MEMSYS3
+        sqlite3Config.m = *sqlite3MemGetMemsys3();
+#endif
+#ifdef SQLITE_ENABLE_MEMSYS5
+        sqlite3Config.m = *sqlite3MemGetMemsys5();
+#endif
+      }
+      break;
+    }
+#endif
+
+#if defined(SQLITE_ENABLE_MEMSYS6)
+    case SQLITE_CONFIG_CHUNKALLOC: {
+      sqlite3Config.nSmall = va_arg(ap, int);
+      sqlite3Config.m = *sqlite3MemGetMemsys6();
+      break;
+    }
+#endif
+
+    case SQLITE_CONFIG_LOOKASIDE: {
+      sqlite3Config.szLookaside = va_arg(ap, int);
+      sqlite3Config.nLookaside = va_arg(ap, int);
+      break;
+    }
+
+    default: {
+      rc = SQLITE_ERROR;
+      break;
+    }
+  }
+  va_end(ap);
+  return rc;
+}
+
+/*
+** Set up the lookaside buffers for a database connection.
+** Return SQLITE_OK on success.  
+** If lookaside is already active, return SQLITE_BUSY.
+**
+** The sz parameter is the number of bytes in each lookaside slot.
+** The cnt parameter is the number of slots.  If pStart is NULL the
+** space for the lookaside memory is obtained from sqlite3_malloc().
+** If pStart is not NULL then it is sz*cnt bytes of memory to use for
+** the lookaside memory.
+*/
+static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
+  void *pStart;
+  if( db->lookaside.nOut ){
+    return SQLITE_BUSY;
+  }
+  if( sz<0 ) sz = 0;
+  if( cnt<0 ) cnt = 0;
+  sz = (sz+7)&~7;
+  if( pBuf==0 ){
+    sqlite3BeginBenignMalloc();
+    pStart = sqlite3Malloc( sz*cnt );
+    sqlite3EndBenignMalloc();
+  }else{
+    pStart = pBuf;
+  }
+  if( db->lookaside.bMalloced ){
+    sqlite3_free(db->lookaside.pStart);
+  }
+  db->lookaside.pStart = pStart;
+  db->lookaside.pFree = 0;
+  db->lookaside.sz = sz;
+  db->lookaside.bMalloced = pBuf==0;
+  if( pStart ){
+    int i;
+    LookasideSlot *p;
+    p = (LookasideSlot*)pStart;
+    for(i=cnt-1; i>=0; i--){
+      p->pNext = db->lookaside.pFree;
+      db->lookaside.pFree = p;
+      p = (LookasideSlot*)&((u8*)p)[sz];
+    }
+    db->lookaside.pEnd = p;
+    db->lookaside.bEnabled = 1;
+  }else{
+    db->lookaside.pEnd = 0;
+    db->lookaside.bEnabled = 0;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Configuration settings for an individual database connection
+*/
+int sqlite3_db_config(sqlite3 *db, int op, ...){
+  va_list ap;
+  int rc;
+  va_start(ap, op);
+  switch( op ){
+    case SQLITE_DBCONFIG_LOOKASIDE: {
+      void *pBuf = va_arg(ap, void*);
+      int sz = va_arg(ap, int);
+      int cnt = va_arg(ap, int);
+      rc = setupLookaside(db, pBuf, sz, cnt);
+      break;
+    }
+    default: {
+      rc = SQLITE_ERROR;
+      break;
+    }
+  }
+  va_end(ap);
+  return rc;
+}
+
+/*
+** Routine needed to support the testcase() macro.
+*/
+#ifdef SQLITE_COVERAGE_TEST
+void sqlite3Coverage(int x){
+  static int dummy = 0;
+  dummy += x;
+}
+#endif
+
+
+/*
+** Return true if the buffer z[0..n-1] contains all spaces.
+*/
+static int allSpaces(const char *z, int n){
+  while( n>0 && z[n-1]==' ' ){ n--; }
+  return n==0;
+}
+
+/*
+** This is the default collating function named "BINARY" which is always
+** available.
+**
+** If the padFlag argument is not NULL then space padding at the end
+** of strings is ignored.  This implements the RTRIM collation.
+*/
+static int binCollFunc(
+  void *padFlag,
+  int nKey1, const void *pKey1,
+  int nKey2, const void *pKey2
+){
+  int rc, n;
+  n = nKey1<nKey2 ? nKey1 : nKey2;
+  rc = memcmp(pKey1, pKey2, n);
+  if( rc==0 ){
+    if( padFlag
+     && allSpaces(((char*)pKey1)+n, nKey1-n)
+     && allSpaces(((char*)pKey2)+n, nKey2-n)
+    ){
+      /* Leave rc unchanged at 0 */
+    }else{
+      rc = nKey1 - nKey2;
+    }
+  }
+  return rc;
+}
+
+/*
+** Another built-in collating sequence: NOCASE. 
+**
+** This collating sequence is intended to be used for "case independant
+** comparison". SQLite's knowledge of upper and lower case equivalents
+** extends only to the 26 characters used in the English language.
+**
+** At the moment there is only a UTF-8 implementation.
+*/
+static int nocaseCollatingFunc(
+  void *NotUsed,
+  int nKey1, const void *pKey1,
+  int nKey2, const void *pKey2
+){
+  int r = sqlite3StrNICmp(
+      (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
+  if( 0==r ){
+    r = nKey1-nKey2;
+  }
+  return r;
+}
+
+/*
+** Return the ROWID of the most recent insert
+*/
+sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
+  return db->lastRowid;
+}
+
+/*
+** Return the number of changes in the most recent call to sqlite3_exec().
+*/
+int sqlite3_changes(sqlite3 *db){
+  return db->nChange;
+}
+
+/*
+** Return the number of changes since the database handle was opened.
+*/
+int sqlite3_total_changes(sqlite3 *db){
+  return db->nTotalChange;
+}
+
+/*
+** Close an existing SQLite database
+*/
+int sqlite3_close(sqlite3 *db){
+  HashElem *i;
+  int j;
+
+  if( !db ){
+    return SQLITE_OK;
+  }
+  if( !sqlite3SafetyCheckSickOrOk(db) ){
+    return SQLITE_MISUSE;
+  }
+  sqlite3_mutex_enter(db->mutex);
+
+#ifdef SQLITE_SSE
+  {
+    extern void sqlite3SseCleanup(sqlite3*);
+    sqlite3SseCleanup(db);
+  }
+#endif 
+
+  sqlite3ResetInternalSchema(db, 0);
+
+  /* If a transaction is open, the ResetInternalSchema() call above
+  ** will not have called the xDisconnect() method on any virtual
+  ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
+  ** call will do so. We need to do this before the check for active
+  ** SQL statements below, as the v-table implementation may be storing
+  ** some prepared statements internally.
+  */
+  sqlite3VtabRollback(db);
+
+  /* If there are any outstanding VMs, return SQLITE_BUSY. */
+  if( db->pVdbe ){
+    sqlite3Error(db, SQLITE_BUSY, 
+        "Unable to close due to unfinalised statements");
+    sqlite3_mutex_leave(db->mutex);
+    return SQLITE_BUSY;
+  }
+  assert( sqlite3SafetyCheckSickOrOk(db) );
+
+  for(j=0; j<db->nDb; j++){
+    struct Db *pDb = &db->aDb[j];
+    if( pDb->pBt ){
+      sqlite3BtreeClose(pDb->pBt);
+      pDb->pBt = 0;
+      if( j!=1 ){
+        pDb->pSchema = 0;
+      }
+    }
+  }
+  sqlite3ResetInternalSchema(db, 0);
+  assert( db->nDb<=2 );
+  assert( db->aDb==db->aDbStatic );
+  for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
+    FuncDef *pFunc, *pNext;
+    for(pFunc = (FuncDef*)sqliteHashData(i); pFunc; pFunc=pNext){
+      pNext = pFunc->pNext;
+      sqlite3DbFree(db, pFunc);
+    }
+  }
+
+  for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
+    CollSeq *pColl = (CollSeq *)sqliteHashData(i);
+    /* Invoke any destructors registered for collation sequence user data. */
+    for(j=0; j<3; j++){
+      if( pColl[j].xDel ){
+        pColl[j].xDel(pColl[j].pUser);
+      }
+    }
+    sqlite3DbFree(db, pColl);
+  }
+  sqlite3HashClear(&db->aCollSeq);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
+    Module *pMod = (Module *)sqliteHashData(i);
+    if( pMod->xDestroy ){
+      pMod->xDestroy(pMod->pAux);
+    }
+    sqlite3DbFree(db, pMod);
+  }
+  sqlite3HashClear(&db->aModule);
+#endif
+
+  sqlite3HashClear(&db->aFunc);
+  sqlite3Error(db, SQLITE_OK, 0); /* Deallocates any cached error strings. */
+  if( db->pErr ){
+    sqlite3ValueFree(db->pErr);
+  }
+  sqlite3CloseExtensions(db);
+
+  db->magic = SQLITE_MAGIC_ERROR;
+
+  /* The temp-database schema is allocated differently from the other schema
+  ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
+  ** So it needs to be freed here. Todo: Why not roll the temp schema into
+  ** the same sqliteMalloc() as the one that allocates the database 
+  ** structure?
+  */
+  sqlite3DbFree(db, db->aDb[1].pSchema);
+  sqlite3_mutex_leave(db->mutex);
+  db->magic = SQLITE_MAGIC_CLOSED;
+  sqlite3_mutex_free(db->mutex);
+  if( db->lookaside.bMalloced ){
+    sqlite3_free(db->lookaside.pStart);
+  }
+  sqlite3_free(db);
+  return SQLITE_OK;
+}
+
+/*
+** Rollback all database files.
+*/
+void sqlite3RollbackAll(sqlite3 *db){
+  int i;
+  int inTrans = 0;
+  assert( sqlite3_mutex_held(db->mutex) );
+  sqlite3BeginBenignMalloc();
+  for(i=0; i<db->nDb; i++){
+    if( db->aDb[i].pBt ){
+      if( sqlite3BtreeIsInTrans(db->aDb[i].pBt) ){
+        inTrans = 1;
+      }
+      sqlite3BtreeRollback(db->aDb[i].pBt);
+      db->aDb[i].inTrans = 0;
+    }
+  }
+  sqlite3VtabRollback(db);
+  sqlite3EndBenignMalloc();
+
+  if( db->flags&SQLITE_InternChanges ){
+    sqlite3ExpirePreparedStatements(db);
+    sqlite3ResetInternalSchema(db, 0);
+  }
+
+  /* If one has been configured, invoke the rollback-hook callback */
+  if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
+    db->xRollbackCallback(db->pRollbackArg);
+  }
+}
+
+/*
+** Return a static string that describes the kind of error specified in the
+** argument.
+*/
+const char *sqlite3ErrStr(int rc){
+  const char *z;
+  switch( rc & 0xff ){
+    case SQLITE_ROW:
+    case SQLITE_DONE:
+    case SQLITE_OK:         z = "not an error";                          break;
+    case SQLITE_ERROR:      z = "SQL logic error or missing database";   break;
+    case SQLITE_PERM:       z = "access permission denied";              break;
+    case SQLITE_ABORT:      z = "callback requested query abort";        break;
+    case SQLITE_BUSY:       z = "database is locked";                    break;
+    case SQLITE_LOCKED:     z = "database table is locked";              break;
+    case SQLITE_NOMEM:      z = "out of memory";                         break;
+    case SQLITE_READONLY:   z = "attempt to write a readonly database";  break;
+    case SQLITE_INTERRUPT:  z = "interrupted";                           break;
+    case SQLITE_IOERR:      z = "disk I/O error";                        break;
+    case SQLITE_CORRUPT:    z = "database disk image is malformed";      break;
+    case SQLITE_FULL:       z = "database or disk is full";              break;
+    case SQLITE_CANTOPEN:   z = "unable to open database file";          break;
+    case SQLITE_EMPTY:      z = "table contains no data";                break;
+    case SQLITE_SCHEMA:     z = "database schema has changed";           break;
+    case SQLITE_TOOBIG:     z = "String or BLOB exceeded size limit";    break;
+    case SQLITE_CONSTRAINT: z = "constraint failed";                     break;
+    case SQLITE_MISMATCH:   z = "datatype mismatch";                     break;
+    case SQLITE_MISUSE:     z = "library routine called out of sequence";break;
+    case SQLITE_NOLFS:      z = "large file support is disabled";        break;
+    case SQLITE_AUTH:       z = "authorization denied";                  break;
+    case SQLITE_FORMAT:     z = "auxiliary database format error";       break;
+    case SQLITE_RANGE:      z = "bind or column index out of range";     break;
+    case SQLITE_NOTADB:     z = "file is encrypted or is not a database";break;
+    default:                z = "unknown error";                         break;
+  }
+  return z;
+}
+
+/*
+** This routine implements a busy callback that sleeps and tries
+** again until a timeout value is reached.  The timeout value is
+** an integer number of milliseconds passed in as the first
+** argument.
+*/
+static int sqliteDefaultBusyCallback(
+ void *ptr,               /* Database connection */
+ int count                /* Number of times table has been busy */
+){
+#if SQLITE_OS_WIN || (defined(HAVE_USLEEP) && HAVE_USLEEP)
+  static const u8 delays[] =
+     { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
+  static const u8 totals[] =
+     { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
+# define NDELAY (sizeof(delays)/sizeof(delays[0]))
+  sqlite3 *db = (sqlite3 *)ptr;
+  int timeout = db->busyTimeout;
+  int delay, prior;
+
+  assert( count>=0 );
+  if( count < NDELAY ){
+    delay = delays[count];
+    prior = totals[count];
+  }else{
+    delay = delays[NDELAY-1];
+    prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
+  }
+  if( prior + delay > timeout ){
+    delay = timeout - prior;
+    if( delay<=0 ) return 0;
+  }
+  sqlite3OsSleep(db->pVfs, delay*1000);
+  return 1;
+#else
+  sqlite3 *db = (sqlite3 *)ptr;
+  int timeout = ((sqlite3 *)ptr)->busyTimeout;
+  if( (count+1)*1000 > timeout ){
+    return 0;
+  }
+  sqlite3OsSleep(db->pVfs, 1000000);
+  return 1;
+#endif
+}
+
+/*
+** Invoke the given busy handler.
+**
+** This routine is called when an operation failed with a lock.
+** If this routine returns non-zero, the lock is retried.  If it
+** returns 0, the operation aborts with an SQLITE_BUSY error.
+*/
+int sqlite3InvokeBusyHandler(BusyHandler *p){
+  int rc;
+  if( NEVER(p==0) || p->xFunc==0 || p->nBusy<0 ) return 0;
+  rc = p->xFunc(p->pArg, p->nBusy);
+  if( rc==0 ){
+    p->nBusy = -1;
+  }else{
+    p->nBusy++;
+  }
+  return rc; 
+}
+
+/*
+** This routine sets the busy callback for an Sqlite database to the
+** given callback function with the given argument.
+*/
+int sqlite3_busy_handler(
+  sqlite3 *db,
+  int (*xBusy)(void*,int),
+  void *pArg
+){
+  sqlite3_mutex_enter(db->mutex);
+  db->busyHandler.xFunc = xBusy;
+  db->busyHandler.pArg = pArg;
+  db->busyHandler.nBusy = 0;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+/*
+** This routine sets the progress callback for an Sqlite database to the
+** given callback function with the given argument. The progress callback will
+** be invoked every nOps opcodes.
+*/
+void sqlite3_progress_handler(
+  sqlite3 *db, 
+  int nOps,
+  int (*xProgress)(void*), 
+  void *pArg
+){
+  sqlite3_mutex_enter(db->mutex);
+  if( nOps>0 ){
+    db->xProgress = xProgress;
+    db->nProgressOps = nOps;
+    db->pProgressArg = pArg;
+  }else{
+    db->xProgress = 0;
+    db->nProgressOps = 0;
+    db->pProgressArg = 0;
+  }
+  sqlite3_mutex_leave(db->mutex);
+}
+#endif
+
+
+/*
+** This routine installs a default busy handler that waits for the
+** specified number of milliseconds before returning 0.
+*/
+int sqlite3_busy_timeout(sqlite3 *db, int ms){
+  if( ms>0 ){
+    db->busyTimeout = ms;
+    sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
+  }else{
+    sqlite3_busy_handler(db, 0, 0);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Cause any pending operation to stop at its earliest opportunity.
+*/
+void sqlite3_interrupt(sqlite3 *db){
+  db->u1.isInterrupted = 1;
+}
+
+
+/*
+** This function is exactly the same as sqlite3_create_function(), except
+** that it is designed to be called by internal code. The difference is
+** that if a malloc() fails in sqlite3_create_function(), an error code
+** is returned and the mallocFailed flag cleared. 
+*/
+int sqlite3CreateFunc(
+  sqlite3 *db,
+  const char *zFunctionName,
+  int nArg,
+  int enc,
+  void *pUserData,
+  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
+  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
+  void (*xFinal)(sqlite3_context*)
+){
+  FuncDef *p;
+  int nName;
+
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( zFunctionName==0 ||
+      (xFunc && (xFinal || xStep)) || 
+      (!xFunc && (xFinal && !xStep)) ||
+      (!xFunc && (!xFinal && xStep)) ||
+      (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
+      (255<(nName = sqlite3Strlen(db, zFunctionName))) ){
+    sqlite3Error(db, SQLITE_ERROR, "bad parameters");
+    return SQLITE_ERROR;
+  }
+  
+#ifndef SQLITE_OMIT_UTF16
+  /* If SQLITE_UTF16 is specified as the encoding type, transform this
+  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
+  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
+  **
+  ** If SQLITE_ANY is specified, add three versions of the function
+  ** to the hash table.
+  */
+  if( enc==SQLITE_UTF16 ){
+    enc = SQLITE_UTF16NATIVE;
+  }else if( enc==SQLITE_ANY ){
+    int rc;
+    rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8,
+         pUserData, xFunc, xStep, xFinal);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE,
+          pUserData, xFunc, xStep, xFinal);
+    }
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    enc = SQLITE_UTF16BE;
+  }
+#else
+  enc = SQLITE_UTF8;
+#endif
+  
+  /* Check if an existing function is being overridden or deleted. If so,
+  ** and there are active VMs, then return SQLITE_BUSY. If a function
+  ** is being overridden/deleted but there are no active VMs, allow the
+  ** operation to continue but invalidate all precompiled statements.
+  */
+  p = sqlite3FindFunction(db, zFunctionName, nName, nArg, enc, 0);
+  if( p && p->iPrefEnc==enc && p->nArg==nArg ){
+    if( db->activeVdbeCnt ){
+      sqlite3Error(db, SQLITE_BUSY, 
+        "Unable to delete/modify user-function due to active statements");
+      assert( !db->mallocFailed );
+      return SQLITE_BUSY;
+    }else{
+      sqlite3ExpirePreparedStatements(db);
+    }
+  }
+
+  p = sqlite3FindFunction(db, zFunctionName, nName, nArg, enc, 1);
+  assert(p || db->mallocFailed);
+  if( !p ){
+    return SQLITE_NOMEM;
+  }
+  p->flags = 0;
+  p->xFunc = xFunc;
+  p->xStep = xStep;
+  p->xFinalize = xFinal;
+  p->pUserData = pUserData;
+  p->nArg = nArg;
+  return SQLITE_OK;
+}
+
+/*
+** Create new user functions.
+*/
+int sqlite3_create_function(
+  sqlite3 *db,
+  const char *zFunctionName,
+  int nArg,
+  int enc,
+  void *p,
+  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
+  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
+  void (*xFinal)(sqlite3_context*)
+){
+  int rc;
+  sqlite3_mutex_enter(db->mutex);
+  rc = sqlite3CreateFunc(db, zFunctionName, nArg, enc, p, xFunc, xStep, xFinal);
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+int sqlite3_create_function16(
+  sqlite3 *db,
+  const void *zFunctionName,
+  int nArg,
+  int eTextRep,
+  void *p,
+  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
+  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
+  void (*xFinal)(sqlite3_context*)
+){
+  int rc;
+  char *zFunc8;
+  sqlite3_mutex_enter(db->mutex);
+  assert( !db->mallocFailed );
+  zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1);
+  rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xFunc, xStep, xFinal);
+  sqlite3DbFree(db, zFunc8);
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+#endif
+
+
+/*
+** Declare that a function has been overloaded by a virtual table.
+**
+** If the function already exists as a regular global function, then
+** this routine is a no-op.  If the function does not exist, then create
+** a new one that always throws a run-time error.  
+**
+** When virtual tables intend to provide an overloaded function, they
+** should call this routine to make sure the global function exists.
+** A global function must exist in order for name resolution to work
+** properly.
+*/
+int sqlite3_overload_function(
+  sqlite3 *db,
+  const char *zName,
+  int nArg
+){
+  int nName = sqlite3Strlen(db, zName);
+  int rc;
+  sqlite3_mutex_enter(db->mutex);
+  if( sqlite3FindFunction(db, zName, nName, nArg, SQLITE_UTF8, 0)==0 ){
+    sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
+                      0, sqlite3InvalidFunction, 0, 0);
+  }
+  rc = sqlite3ApiExit(db, SQLITE_OK);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_TRACE
+/*
+** Register a trace function.  The pArg from the previously registered trace
+** is returned.  
+**
+** A NULL trace function means that no tracing is executes.  A non-NULL
+** trace is a pointer to a function that is invoked at the start of each
+** SQL statement.
+*/
+void *sqlite3_trace(sqlite3 *db, void (*xTrace)(void*,const char*), void *pArg){
+  void *pOld;
+  sqlite3_mutex_enter(db->mutex);
+  pOld = db->pTraceArg;
+  db->xTrace = xTrace;
+  db->pTraceArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pOld;
+}
+/*
+** Register a profile function.  The pArg from the previously registered 
+** profile function is returned.  
+**
+** A NULL profile function means that no profiling is executes.  A non-NULL
+** profile is a pointer to a function that is invoked at the conclusion of
+** each SQL statement that is run.
+*/
+void *sqlite3_profile(
+  sqlite3 *db,
+  void (*xProfile)(void*,const char*,sqlite_uint64),
+  void *pArg
+){
+  void *pOld;
+  sqlite3_mutex_enter(db->mutex);
+  pOld = db->pProfileArg;
+  db->xProfile = xProfile;
+  db->pProfileArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pOld;
+}
+#endif /* SQLITE_OMIT_TRACE */
+
+/*** EXPERIMENTAL ***
+**
+** Register a function to be invoked when a transaction comments.
+** If the invoked function returns non-zero, then the commit becomes a
+** rollback.
+*/
+void *sqlite3_commit_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  int (*xCallback)(void*),  /* Function to invoke on each commit */
+  void *pArg                /* Argument to the function */
+){
+  void *pOld;
+  sqlite3_mutex_enter(db->mutex);
+  pOld = db->pCommitArg;
+  db->xCommitCallback = xCallback;
+  db->pCommitArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pOld;
+}
+
+/*
+** Register a callback to be invoked each time a row is updated,
+** inserted or deleted using this database connection.
+*/
+void *sqlite3_update_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
+  void *pArg                /* Argument to the function */
+){
+  void *pRet;
+  sqlite3_mutex_enter(db->mutex);
+  pRet = db->pUpdateArg;
+  db->xUpdateCallback = xCallback;
+  db->pUpdateArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pRet;
+}
+
+/*
+** Register a callback to be invoked each time a transaction is rolled
+** back by this database connection.
+*/
+void *sqlite3_rollback_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  void (*xCallback)(void*), /* Callback function */
+  void *pArg                /* Argument to the function */
+){
+  void *pRet;
+  sqlite3_mutex_enter(db->mutex);
+  pRet = db->pRollbackArg;
+  db->xRollbackCallback = xCallback;
+  db->pRollbackArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pRet;
+}
+
+/*
+** This routine is called to create a connection to a database BTree
+** driver.  If zFilename is the name of a file, then that file is
+** opened and used.  If zFilename is the magic name ":memory:" then
+** the database is stored in memory (and is thus forgotten as soon as
+** the connection is closed.)  If zFilename is NULL then the database
+** is a "virtual" database for transient use only and is deleted as
+** soon as the connection is closed.
+**
+** A virtual database can be either a disk file (that is automatically
+** deleted when the file is closed) or it an be held entirely in memory,
+** depending on the values of the SQLITE_TEMP_STORE compile-time macro and the
+** db->temp_store variable, according to the following chart:
+**
+**   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
+**   -----------------     --------------     ------------------------------
+**   0                     any                file
+**   1                     1                  file
+**   1                     2                  memory
+**   1                     0                  file
+**   2                     1                  file
+**   2                     2                  memory
+**   2                     0                  memory
+**   3                     any                memory
+*/
+int sqlite3BtreeFactory(
+  const sqlite3 *db,        /* Main database when opening aux otherwise 0 */
+  const char *zFilename,    /* Name of the file containing the BTree database */
+  int omitJournal,          /* if TRUE then do not journal this file */
+  int nCache,               /* How many pages in the page cache */
+  int vfsFlags,             /* Flags passed through to vfsOpen */
+  Btree **ppBtree           /* Pointer to new Btree object written here */
+){
+  int btFlags = 0;
+  int rc;
+  
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( ppBtree != 0);
+  if( omitJournal ){
+    btFlags |= BTREE_OMIT_JOURNAL;
+  }
+  if( db->flags & SQLITE_NoReadlock ){
+    btFlags |= BTREE_NO_READLOCK;
+  }
+  if( zFilename==0 ){
+#if SQLITE_TEMP_STORE==0
+    /* Do nothing */
+#endif
+#ifndef SQLITE_OMIT_MEMORYDB
+#if SQLITE_TEMP_STORE==1
+    if( db->temp_store==2 ) zFilename = ":memory:";
+#endif
+#if SQLITE_TEMP_STORE==2
+    if( db->temp_store!=1 ) zFilename = ":memory:";
+#endif
+#if SQLITE_TEMP_STORE==3
+    zFilename = ":memory:";
+#endif
+#endif /* SQLITE_OMIT_MEMORYDB */
+  }
+
+  if( (vfsFlags & SQLITE_OPEN_MAIN_DB)!=0 && (zFilename==0 || *zFilename==0) ){
+    vfsFlags = (vfsFlags & ~SQLITE_OPEN_MAIN_DB) | SQLITE_OPEN_TEMP_DB;
+  }
+  rc = sqlite3BtreeOpen(zFilename, (sqlite3 *)db, ppBtree, btFlags, vfsFlags);
+
+  /* If the B-Tree was successfully opened, set the pager-cache size to the
+  ** default value. Except, if the call to BtreeOpen() returned a handle
+  ** open on an existing shared pager-cache, do not change the pager-cache 
+  ** size.
+  */
+  if( rc==SQLITE_OK && 0==sqlite3BtreeSchema(*ppBtree, 0, 0) ){
+    sqlite3BtreeSetCacheSize(*ppBtree, nCache);
+  }
+  return rc;
+}
+
+/*
+** Return UTF-8 encoded English language explanation of the most recent
+** error.
+*/
+const char *sqlite3_errmsg(sqlite3 *db){
+  const char *z;
+  if( !db ){
+    return sqlite3ErrStr(SQLITE_NOMEM);
+  }
+  if( !sqlite3SafetyCheckSickOrOk(db) ){
+    return sqlite3ErrStr(SQLITE_MISUSE);
+  }
+  sqlite3_mutex_enter(db->mutex);
+  assert( !db->mallocFailed );
+  z = (char*)sqlite3_value_text(db->pErr);
+  assert( !db->mallocFailed );
+  if( z==0 ){
+    z = sqlite3ErrStr(db->errCode);
+  }
+  sqlite3_mutex_leave(db->mutex);
+  return z;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Return UTF-16 encoded English language explanation of the most recent
+** error.
+*/
+const void *sqlite3_errmsg16(sqlite3 *db){
+  /* Because all the characters in the string are in the unicode
+  ** range 0x00-0xFF, if we pad the big-endian string with a 
+  ** zero byte, we can obtain the little-endian string with
+  ** &big_endian[1].
+  */
+  static const char outOfMemBe[] = {
+    0, 'o', 0, 'u', 0, 't', 0, ' ', 
+    0, 'o', 0, 'f', 0, ' ', 
+    0, 'm', 0, 'e', 0, 'm', 0, 'o', 0, 'r', 0, 'y', 0, 0, 0
+  };
+  static const char misuseBe [] = {
+    0, 'l', 0, 'i', 0, 'b', 0, 'r', 0, 'a', 0, 'r', 0, 'y', 0, ' ', 
+    0, 'r', 0, 'o', 0, 'u', 0, 't', 0, 'i', 0, 'n', 0, 'e', 0, ' ', 
+    0, 'c', 0, 'a', 0, 'l', 0, 'l', 0, 'e', 0, 'd', 0, ' ', 
+    0, 'o', 0, 'u', 0, 't', 0, ' ', 
+    0, 'o', 0, 'f', 0, ' ', 
+    0, 's', 0, 'e', 0, 'q', 0, 'u', 0, 'e', 0, 'n', 0, 'c', 0, 'e', 0, 0, 0
+  };
+
+  const void *z;
+  if( !db ){
+    return (void *)(&outOfMemBe[SQLITE_UTF16NATIVE==SQLITE_UTF16LE?1:0]);
+  }
+  if( !sqlite3SafetyCheckSickOrOk(db) ){
+    return (void *)(&misuseBe[SQLITE_UTF16NATIVE==SQLITE_UTF16LE?1:0]);
+  }
+  sqlite3_mutex_enter(db->mutex);
+  assert( !db->mallocFailed );
+  z = sqlite3_value_text16(db->pErr);
+  if( z==0 ){
+    sqlite3ValueSetStr(db->pErr, -1, sqlite3ErrStr(db->errCode),
+         SQLITE_UTF8, SQLITE_STATIC);
+    z = sqlite3_value_text16(db->pErr);
+  }
+  /* A malloc() may have failed within the call to sqlite3_value_text16()
+  ** above. If this is the case, then the db->mallocFailed flag needs to
+  ** be cleared before returning. Do this directly, instead of via
+  ** sqlite3ApiExit(), to avoid setting the database handle error message.
+  */
+  db->mallocFailed = 0;
+  sqlite3_mutex_leave(db->mutex);
+  return z;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+/*
+** Return the most recent error code generated by an SQLite routine. If NULL is
+** passed to this function, we assume a malloc() failed during sqlite3_open().
+*/
+int sqlite3_errcode(sqlite3 *db){
+  if( db && !sqlite3SafetyCheckSickOrOk(db) ){
+    return SQLITE_MISUSE;
+  }
+  if( !db || db->mallocFailed ){
+    return SQLITE_NOMEM;
+  }
+  return db->errCode & db->errMask;
+}
+
+/*
+** Create a new collating function for database "db".  The name is zName
+** and the encoding is enc.
+*/
+static int createCollation(
+  sqlite3* db, 
+  const char *zName, 
+  int enc, 
+  void* pCtx,
+  int(*xCompare)(void*,int,const void*,int,const void*),
+  void(*xDel)(void*)
+){
+  CollSeq *pColl;
+  int enc2;
+  int nName;
+  
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  /* If SQLITE_UTF16 is specified as the encoding type, transform this
+  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
+  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
+  */
+  enc2 = enc & ~SQLITE_UTF16_ALIGNED;
+  if( enc2==SQLITE_UTF16 ){
+    enc2 = SQLITE_UTF16NATIVE;
+  }
+  if( (enc2&~3)!=0 ){
+    return SQLITE_MISUSE;
+  }
+
+  /* Check if this call is removing or replacing an existing collation 
+  ** sequence. If so, and there are active VMs, return busy. If there
+  ** are no active VMs, invalidate any pre-compiled statements.
+  */
+  nName = sqlite3Strlen(db, zName);
+  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, nName, 0);
+  if( pColl && pColl->xCmp ){
+    if( db->activeVdbeCnt ){
+      sqlite3Error(db, SQLITE_BUSY, 
+        "Unable to delete/modify collation sequence due to active statements");
+      return SQLITE_BUSY;
+    }
+    sqlite3ExpirePreparedStatements(db);
+
+    /* If collation sequence pColl was created directly by a call to
+    ** sqlite3_create_collation, and not generated by synthCollSeq(),
+    ** then any copies made by synthCollSeq() need to be invalidated.
+    ** Also, collation destructor - CollSeq.xDel() - function may need
+    ** to be called.
+    */ 
+    if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
+      CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName, nName);
+      int j;
+      for(j=0; j<3; j++){
+        CollSeq *p = &aColl[j];
+        if( p->enc==pColl->enc ){
+          if( p->xDel ){
+            p->xDel(p->pUser);
+          }
+          p->xCmp = 0;
+        }
+      }
+    }
+  }
+
+  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, nName, 1);
+  if( pColl ){
+    pColl->xCmp = xCompare;
+    pColl->pUser = pCtx;
+    pColl->xDel = xDel;
+    pColl->enc = enc2 | (enc & SQLITE_UTF16_ALIGNED);
+  }
+  sqlite3Error(db, SQLITE_OK, 0);
+  return SQLITE_OK;
+}
+
+
+/*
+** This array defines hard upper bounds on limit values.  The
+** initializer must be kept in sync with the SQLITE_LIMIT_*
+** #defines in sqlite3.h.
+*/
+static const int aHardLimit[] = {
+  SQLITE_MAX_LENGTH,
+  SQLITE_MAX_SQL_LENGTH,
+  SQLITE_MAX_COLUMN,
+  SQLITE_MAX_EXPR_DEPTH,
+  SQLITE_MAX_COMPOUND_SELECT,
+  SQLITE_MAX_VDBE_OP,
+  SQLITE_MAX_FUNCTION_ARG,
+  SQLITE_MAX_ATTACHED,
+  SQLITE_MAX_LIKE_PATTERN_LENGTH,
+  SQLITE_MAX_VARIABLE_NUMBER,
+};
+
+/*
+** Make sure the hard limits are set to reasonable values
+*/
+#if SQLITE_MAX_LENGTH<100
+# error SQLITE_MAX_LENGTH must be at least 100
+#endif
+#if SQLITE_MAX_SQL_LENGTH<100
+# error SQLITE_MAX_SQL_LENGTH must be at least 100
+#endif
+#if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
+# error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
+#endif
+#if SQLITE_MAX_COMPOUND_SELECT<2
+# error SQLITE_MAX_COMPOUND_SELECT must be at least 2
+#endif
+#if SQLITE_MAX_VDBE_OP<40
+# error SQLITE_MAX_VDBE_OP must be at least 40
+#endif
+#if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
+# error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
+#endif
+#if SQLITE_MAX_ATTACH<0 || SQLITE_MAX_ATTACH>30
+# error SQLITE_MAX_ATTACH must be between 0 and 30
+#endif
+#if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
+# error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
+#endif
+#if SQLITE_MAX_VARIABLE_NUMBER<1
+# error SQLITE_MAX_VARIABLE_NUMBER must be at least 1
+#endif
+
+
+/*
+** Change the value of a limit.  Report the old value.
+** If an invalid limit index is supplied, report -1.
+** Make no changes but still report the old value if the
+** new limit is negative.
+**
+** A new lower limit does not shrink existing constructs.
+** It merely prevents new constructs that exceed the limit
+** from forming.
+*/
+int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
+  int oldLimit;
+  if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
+    return -1;
+  }
+  oldLimit = db->aLimit[limitId];
+  if( newLimit>=0 ){
+    if( newLimit>aHardLimit[limitId] ){
+      newLimit = aHardLimit[limitId];
+    }
+    db->aLimit[limitId] = newLimit;
+  }
+  return oldLimit;
+}
+
+/*
+** This routine does the work of opening a database on behalf of
+** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"  
+** is UTF-8 encoded.
+*/
+static int openDatabase(
+  const char *zFilename, /* Database filename UTF-8 encoded */
+  sqlite3 **ppDb,        /* OUT: Returned database handle */
+  unsigned flags,        /* Operational flags */
+  const char *zVfs       /* Name of the VFS to use */
+){
+  sqlite3 *db;
+  int rc;
+  CollSeq *pColl;
+  int isThreadsafe = 1;
+
+#ifndef SQLITE_OMIT_AUTOINIT
+  rc = sqlite3_initialize();
+  if( rc ) return rc;
+#endif
+
+  if( flags&SQLITE_OPEN_NOMUTEX ){
+    isThreadsafe = 0;
+  }
+
+  /* Remove harmful bits from the flags parameter */
+  flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
+               SQLITE_OPEN_MAIN_DB |
+               SQLITE_OPEN_TEMP_DB | 
+               SQLITE_OPEN_TRANSIENT_DB | 
+               SQLITE_OPEN_MAIN_JOURNAL | 
+               SQLITE_OPEN_TEMP_JOURNAL | 
+               SQLITE_OPEN_SUBJOURNAL | 
+               SQLITE_OPEN_MASTER_JOURNAL |
+               SQLITE_OPEN_NOMUTEX
+             );
+
+  /* Allocate the sqlite data structure */
+  db = sqlite3MallocZero( sizeof(sqlite3) );
+  if( db==0 ) goto opendb_out;
+  if( sqlite3Config.bFullMutex && isThreadsafe ){
+    db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
+    if( db->mutex==0 ){
+      sqlite3_free(db);
+      db = 0;
+      goto opendb_out;
+    }
+  }
+  sqlite3_mutex_enter(db->mutex);
+  db->errMask = 0xff;
+  db->priorNewRowid = 0;
+  db->nDb = 2;
+  db->magic = SQLITE_MAGIC_BUSY;
+  db->aDb = db->aDbStatic;
+
+  assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
+  memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
+  db->autoCommit = 1;
+  db->nextAutovac = -1;
+  db->nextPagesize = 0;
+  db->flags |= SQLITE_ShortColNames
+#if SQLITE_DEFAULT_FILE_FORMAT<4
+                 | SQLITE_LegacyFileFmt
+#endif
+#ifdef SQLITE_ENABLE_LOAD_EXTENSION
+                 | SQLITE_LoadExtension
+#endif
+      ;
+  sqlite3HashInit(&db->aFunc, SQLITE_HASH_STRING, 0);
+  sqlite3HashInit(&db->aCollSeq, SQLITE_HASH_STRING, 0);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3HashInit(&db->aModule, SQLITE_HASH_STRING, 0);
+#endif
+
+  db->pVfs = sqlite3_vfs_find(zVfs);
+  if( !db->pVfs ){
+    rc = SQLITE_ERROR;
+    db->magic = SQLITE_MAGIC_SICK;
+    sqlite3Error(db, rc, "no such vfs: %s", zVfs);
+    goto opendb_out;
+  }
+
+  /* Add the default collation sequence BINARY. BINARY works for both UTF-8
+  ** and UTF-16, so add a version for each to avoid any unnecessary
+  ** conversions. The only error that can occur here is a malloc() failure.
+  */
+  createCollation(db, "BINARY", SQLITE_UTF8, 0, binCollFunc, 0);
+  createCollation(db, "BINARY", SQLITE_UTF16BE, 0, binCollFunc, 0);
+  createCollation(db, "BINARY", SQLITE_UTF16LE, 0, binCollFunc, 0);
+  createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
+  if( db->mallocFailed ){
+    db->magic = SQLITE_MAGIC_SICK;
+    goto opendb_out;
+  }
+  db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0);
+  assert( db->pDfltColl!=0 );
+
+  /* Also add a UTF-8 case-insensitive collation sequence. */
+  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
+
+  /* Set flags on the built-in collating sequences */
+  db->pDfltColl->type = SQLITE_COLL_BINARY;
+  pColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "NOCASE", 6, 0);
+  if( pColl ){
+    pColl->type = SQLITE_COLL_NOCASE;
+  }
+
+  /* Open the backend database driver */
+  db->openFlags = flags;
+  rc = sqlite3BtreeFactory(db, zFilename, 0, SQLITE_DEFAULT_CACHE_SIZE, 
+                           flags | SQLITE_OPEN_MAIN_DB,
+                           &db->aDb[0].pBt);
+  if( rc!=SQLITE_OK ){
+    sqlite3Error(db, rc, 0);
+    db->magic = SQLITE_MAGIC_SICK;
+    goto opendb_out;
+  }
+  db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
+  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
+
+
+  /* The default safety_level for the main database is 'full'; for the temp
+  ** database it is 'NONE'. This matches the pager layer defaults.  
+  */
+  db->aDb[0].zName = "main";
+  db->aDb[0].safety_level = 3;
+#ifndef SQLITE_OMIT_TEMPDB
+  db->aDb[1].zName = "temp";
+  db->aDb[1].safety_level = 1;
+#endif
+
+  db->magic = SQLITE_MAGIC_OPEN;
+  if( db->mallocFailed ){
+    goto opendb_out;
+  }
+
+  /* Register all built-in functions, but do not attempt to read the
+  ** database schema yet. This is delayed until the first time the database
+  ** is accessed.
+  */
+  sqlite3Error(db, SQLITE_OK, 0);
+  sqlite3RegisterBuiltinFunctions(db);
+
+  /* Load automatic extensions - extensions that have been registered
+  ** using the sqlite3_automatic_extension() API.
+  */
+  (void)sqlite3AutoLoadExtensions(db);
+  if( sqlite3_errcode(db)!=SQLITE_OK ){
+    goto opendb_out;
+  }
+
+#ifdef SQLITE_ENABLE_FTS1
+  if( !db->mallocFailed ){
+    extern int sqlite3Fts1Init(sqlite3*);
+    rc = sqlite3Fts1Init(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_FTS2
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    extern int sqlite3Fts2Init(sqlite3*);
+    rc = sqlite3Fts2Init(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_FTS3
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    rc = sqlite3Fts3Init(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_ICU
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    extern int sqlite3IcuInit(sqlite3*);
+    rc = sqlite3IcuInit(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_RTREE
+  if( !db->mallocFailed && rc==SQLITE_OK){
+    rc = sqlite3RtreeInit(db);
+  }
+#endif
+
+  sqlite3Error(db, rc, 0);
+
+  /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
+  ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
+  ** mode.  Doing nothing at all also makes NORMAL the default.
+  */
+#ifdef SQLITE_DEFAULT_LOCKING_MODE
+  db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
+  sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
+                          SQLITE_DEFAULT_LOCKING_MODE);
+#endif
+
+  /* Enable the lookaside-malloc subsystem */
+  setupLookaside(db, 0, sqlite3Config.szLookaside, sqlite3Config.nLookaside);
+
+opendb_out:
+  if( db ){
+    assert( db->mutex!=0 || isThreadsafe==0 || sqlite3Config.bFullMutex==0 );
+    sqlite3_mutex_leave(db->mutex);
+  }
+  if( SQLITE_NOMEM==(rc = sqlite3_errcode(db)) ){
+    sqlite3_close(db);
+    db = 0;
+  }
+  *ppDb = db;
+  return sqlite3ApiExit(0, rc);
+}
+
+/*
+** Open a new database handle.
+*/
+int sqlite3_open(
+  const char *zFilename, 
+  sqlite3 **ppDb 
+){
+  return openDatabase(zFilename, ppDb,
+                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
+}
+int sqlite3_open_v2(
+  const char *filename,   /* Database filename (UTF-8) */
+  sqlite3 **ppDb,         /* OUT: SQLite db handle */
+  int flags,              /* Flags */
+  const char *zVfs        /* Name of VFS module to use */
+){
+  return openDatabase(filename, ppDb, flags, zVfs);
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Open a new database handle.
+*/
+int sqlite3_open16(
+  const void *zFilename, 
+  sqlite3 **ppDb
+){
+  char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
+  sqlite3_value *pVal;
+  int rc;
+
+  assert( zFilename );
+  assert( ppDb );
+  *ppDb = 0;
+#ifndef SQLITE_OMIT_AUTOINIT
+  rc = sqlite3_initialize();
+  if( rc ) return rc;
+#endif
+  pVal = sqlite3ValueNew(0);
+  sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
+  zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
+  if( zFilename8 ){
+    rc = openDatabase(zFilename8, ppDb,
+                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
+    assert( *ppDb || rc==SQLITE_NOMEM );
+    if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
+      ENC(*ppDb) = SQLITE_UTF16NATIVE;
+    }
+  }else{
+    rc = SQLITE_NOMEM;
+  }
+  sqlite3ValueFree(pVal);
+
+  return sqlite3ApiExit(0, rc);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+/*
+** Register a new collation sequence with the database handle db.
+*/
+int sqlite3_create_collation(
+  sqlite3* db, 
+  const char *zName, 
+  int enc, 
+  void* pCtx,
+  int(*xCompare)(void*,int,const void*,int,const void*)
+){
+  int rc;
+  sqlite3_mutex_enter(db->mutex);
+  assert( !db->mallocFailed );
+  rc = createCollation(db, zName, enc, pCtx, xCompare, 0);
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Register a new collation sequence with the database handle db.
+*/
+int sqlite3_create_collation_v2(
+  sqlite3* db, 
+  const char *zName, 
+  int enc, 
+  void* pCtx,
+  int(*xCompare)(void*,int,const void*,int,const void*),
+  void(*xDel)(void*)
+){
+  int rc;
+  sqlite3_mutex_enter(db->mutex);
+  assert( !db->mallocFailed );
+  rc = createCollation(db, zName, enc, pCtx, xCompare, xDel);
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Register a new collation sequence with the database handle db.
+*/
+int sqlite3_create_collation16(
+  sqlite3* db, 
+  const void *zName,
+  int enc, 
+  void* pCtx,
+  int(*xCompare)(void*,int,const void*,int,const void*)
+){
+  int rc = SQLITE_OK;
+  char *zName8;
+  sqlite3_mutex_enter(db->mutex);
+  assert( !db->mallocFailed );
+  zName8 = sqlite3Utf16to8(db, zName, -1);
+  if( zName8 ){
+    rc = createCollation(db, zName8, enc, pCtx, xCompare, 0);
+    sqlite3DbFree(db, zName8);
+  }
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+/*
+** Register a collation sequence factory callback with the database handle
+** db. Replace any previously installed collation sequence factory.
+*/
+int sqlite3_collation_needed(
+  sqlite3 *db, 
+  void *pCollNeededArg, 
+  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
+){
+  sqlite3_mutex_enter(db->mutex);
+  db->xCollNeeded = xCollNeeded;
+  db->xCollNeeded16 = 0;
+  db->pCollNeededArg = pCollNeededArg;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Register a collation sequence factory callback with the database handle
+** db. Replace any previously installed collation sequence factory.
+*/
+int sqlite3_collation_needed16(
+  sqlite3 *db, 
+  void *pCollNeededArg, 
+  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
+){
+  sqlite3_mutex_enter(db->mutex);
+  db->xCollNeeded = 0;
+  db->xCollNeeded16 = xCollNeeded16;
+  db->pCollNeededArg = pCollNeededArg;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+#ifndef SQLITE_OMIT_GLOBALRECOVER
+/*
+** This function is now an anachronism. It used to be used to recover from a
+** malloc() failure, but SQLite now does this automatically.
+*/
+int sqlite3_global_recover(void){
+  return SQLITE_OK;
+}
+#endif
+
+/*
+** Test to see whether or not the database connection is in autocommit
+** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
+** by default.  Autocommit is disabled by a BEGIN statement and reenabled
+** by the next COMMIT or ROLLBACK.
+**
+******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
+*/
+int sqlite3_get_autocommit(sqlite3 *db){
+  return db->autoCommit;
+}
+
+#ifdef SQLITE_DEBUG
+/*
+** The following routine is subtituted for constant SQLITE_CORRUPT in
+** debugging builds.  This provides a way to set a breakpoint for when
+** corruption is first detected.
+*/
+int sqlite3Corrupt(void){
+  return SQLITE_CORRUPT;
+}
+#endif
+
+/*
+** This is a convenience routine that makes sure that all thread-specific
+** data for this thread has been deallocated.
+**
+** SQLite no longer uses thread-specific data so this routine is now a
+** no-op.  It is retained for historical compatibility.
+*/
+void sqlite3_thread_cleanup(void){
+}
+
+/*
+** Return meta information about a specific column of a database table.
+** See comment in sqlite3.h (sqlite.h.in) for details.
+*/
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+int sqlite3_table_column_metadata(
+  sqlite3 *db,                /* Connection handle */
+  const char *zDbName,        /* Database name or NULL */
+  const char *zTableName,     /* Table name */
+  const char *zColumnName,    /* Column name */
+  char const **pzDataType,    /* OUTPUT: Declared data type */
+  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
+  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
+  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
+  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
+){
+  int rc;
+  char *zErrMsg = 0;
+  Table *pTab = 0;
+  Column *pCol = 0;
+  int iCol;
+
+  char const *zDataType = 0;
+  char const *zCollSeq = 0;
+  int notnull = 0;
+  int primarykey = 0;
+  int autoinc = 0;
+
+  /* Ensure the database schema has been loaded */
+  sqlite3_mutex_enter(db->mutex);
+  (void)sqlite3SafetyOn(db);
+  sqlite3BtreeEnterAll(db);
+  rc = sqlite3Init(db, &zErrMsg);
+  sqlite3BtreeLeaveAll(db);
+  if( SQLITE_OK!=rc ){
+    goto error_out;
+  }
+
+  /* Locate the table in question */
+  pTab = sqlite3FindTable(db, zTableName, zDbName);
+  if( !pTab || pTab->pSelect ){
+    pTab = 0;
+    goto error_out;
+  }
+
+  /* Find the column for which info is requested */
+  if( sqlite3IsRowid(zColumnName) ){
+    iCol = pTab->iPKey;
+    if( iCol>=0 ){
+      pCol = &pTab->aCol[iCol];
+    }
+  }else{
+    for(iCol=0; iCol<pTab->nCol; iCol++){
+      pCol = &pTab->aCol[iCol];
+      if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
+        break;
+      }
+    }
+    if( iCol==pTab->nCol ){
+      pTab = 0;
+      goto error_out;
+    }
+  }
+
+  /* The following block stores the meta information that will be returned
+  ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
+  ** and autoinc. At this point there are two possibilities:
+  ** 
+  **     1. The specified column name was rowid", "oid" or "_rowid_" 
+  **        and there is no explicitly declared IPK column. 
+  **
+  **     2. The table is not a view and the column name identified an 
+  **        explicitly declared column. Copy meta information from *pCol.
+  */ 
+  if( pCol ){
+    zDataType = pCol->zType;
+    zCollSeq = pCol->zColl;
+    notnull = pCol->notNull!=0;
+    primarykey  = pCol->isPrimKey!=0;
+    autoinc = pTab->iPKey==iCol && pTab->autoInc;
+  }else{
+    zDataType = "INTEGER";
+    primarykey = 1;
+  }
+  if( !zCollSeq ){
+    zCollSeq = "BINARY";
+  }
+
+error_out:
+  (void)sqlite3SafetyOff(db);
+
+  /* Whether the function call succeeded or failed, set the output parameters
+  ** to whatever their local counterparts contain. If an error did occur,
+  ** this has the effect of zeroing all output parameters.
+  */
+  if( pzDataType ) *pzDataType = zDataType;
+  if( pzCollSeq ) *pzCollSeq = zCollSeq;
+  if( pNotNull ) *pNotNull = notnull;
+  if( pPrimaryKey ) *pPrimaryKey = primarykey;
+  if( pAutoinc ) *pAutoinc = autoinc;
+
+  if( SQLITE_OK==rc && !pTab ){
+    sqlite3DbFree(db, zErrMsg);
+    zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
+        zColumnName);
+    rc = SQLITE_ERROR;
+  }
+  sqlite3Error(db, rc, (zErrMsg?"%s":0), zErrMsg);
+  sqlite3DbFree(db, zErrMsg);
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+#endif
+
+/*
+** Sleep for a little while.  Return the amount of time slept.
+*/
+int sqlite3_sleep(int ms){
+  sqlite3_vfs *pVfs;
+  int rc;
+  pVfs = sqlite3_vfs_find(0);
+  if( pVfs==0 ) return 0;
+
+  /* This function works in milliseconds, but the underlying OsSleep() 
+  ** API uses microseconds. Hence the 1000's.
+  */
+  rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
+  return rc;
+}
+
+/*
+** Enable or disable the extended result codes.
+*/
+int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
+  sqlite3_mutex_enter(db->mutex);
+  db->errMask = onoff ? 0xffffffff : 0xff;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+/*
+** Invoke the xFileControl method on a particular database.
+*/
+int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
+  int rc = SQLITE_ERROR;
+  int iDb;
+  sqlite3_mutex_enter(db->mutex);
+  if( zDbName==0 ){
+    iDb = 0;
+  }else{
+    for(iDb=0; iDb<db->nDb; iDb++){
+      if( strcmp(db->aDb[iDb].zName, zDbName)==0 ) break;
+    }
+  }
+  if( iDb<db->nDb ){
+    Btree *pBtree = db->aDb[iDb].pBt;
+    if( pBtree ){
+      Pager *pPager;
+      sqlite3_file *fd;
+      sqlite3BtreeEnter(pBtree);
+      pPager = sqlite3BtreePager(pBtree);
+      assert( pPager!=0 );
+      fd = sqlite3PagerFile(pPager);
+      assert( fd!=0 );
+      if( fd->pMethods ){
+        rc = sqlite3OsFileControl(fd, op, pArg);
+      }
+      sqlite3BtreeLeave(pBtree);
+    }
+  }
+  sqlite3_mutex_leave(db->mutex);
+  return rc;   
+}
+
+/*
+** Interface to the testing logic.
+*/
+int sqlite3_test_control(int op, ...){
+  int rc = 0;
+#ifndef SQLITE_OMIT_BUILTIN_TEST
+  va_list ap;
+  va_start(ap, op);
+  switch( op ){
+
+    /*
+    ** Save the current state of the PRNG.
+    */
+    case SQLITE_TESTCTRL_PRNG_SAVE: {
+      sqlite3PrngSaveState();
+      break;
+    }
+
+    /*
+    ** Restore the state of the PRNG to the last state saved using
+    ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
+    ** this verb acts like PRNG_RESET.
+    */
+    case SQLITE_TESTCTRL_PRNG_RESTORE: {
+      sqlite3PrngRestoreState();
+      break;
+    }
+
+    /*
+    ** Reset the PRNG back to its uninitialized state.  The next call
+    ** to sqlite3_randomness() will reseed the PRNG using a single call
+    ** to the xRandomness method of the default VFS.
+    */
+    case SQLITE_TESTCTRL_PRNG_RESET: {
+      sqlite3PrngResetState();
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(BITVEC_TEST, size, program)
+    **
+    ** Run a test against a Bitvec object of size.  The program argument
+    ** is an array of integers that defines the test.  Return -1 on a
+    ** memory allocation error, 0 on success, or non-zero for an error.
+    ** See the sqlite3BitvecBuiltinTest() for additional information.
+    */
+    case SQLITE_TESTCTRL_BITVEC_TEST: {
+      int sz = va_arg(ap, int);
+      int *aProg = va_arg(ap, int*);
+      rc = sqlite3BitvecBuiltinTest(sz, aProg);
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
+    **
+    ** Register hooks to call to indicate which malloc() failures 
+    ** are benign.
+    */
+    case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
+      typedef void (*void_function)(void);
+      void_function xBenignBegin;
+      void_function xBenignEnd;
+      xBenignBegin = va_arg(ap, void_function);
+      xBenignEnd = va_arg(ap, void_function);
+      sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
+      break;
+    }
+  }
+  va_end(ap);
+#endif /* SQLITE_OMIT_BUILTIN_TEST */
+  return rc;
+}
diff --git a/third_party/sqlite/src/malloc.c b/third_party/sqlite/src/malloc.c
new file mode 100755
index 0000000..fa9c88f
--- /dev/null
+++ b/third_party/sqlite/src/malloc.c
@@ -0,0 +1,742 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** Memory allocation functions used throughout sqlite.
+**
+** $Id: malloc.c,v 1.34 2008/08/05 17:53:23 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <stdarg.h>
+#include <ctype.h>
+
+/*
+** This routine runs when the memory allocator sees that the
+** total memory allocation is about to exceed the soft heap
+** limit.
+*/
+static void softHeapLimitEnforcer(
+  void *NotUsed, 
+  sqlite3_int64 inUse,
+  int allocSize
+){
+  sqlite3_release_memory(allocSize);
+}
+
+/*
+** Set the soft heap-size limit for the library. Passing a zero or 
+** negative value indicates no limit.
+*/
+void sqlite3_soft_heap_limit(int n){
+  sqlite3_uint64 iLimit;
+  int overage;
+  if( n<0 ){
+    iLimit = 0;
+  }else{
+    iLimit = n;
+  }
+  sqlite3_initialize();
+  if( iLimit>0 ){
+    sqlite3_memory_alarm(softHeapLimitEnforcer, 0, iLimit);
+  }else{
+    sqlite3_memory_alarm(0, 0, 0);
+  }
+  overage = sqlite3_memory_used() - n;
+  if( overage>0 ){
+    sqlite3_release_memory(overage);
+  }
+}
+
+/*
+** Attempt to release up to n bytes of non-essential memory currently
+** held by SQLite. An example of non-essential memory is memory used to
+** cache database pages that are not currently in use.
+*/
+int sqlite3_release_memory(int n){
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  int nRet = sqlite3VdbeReleaseMemory(n);
+  nRet += sqlite3PagerReleaseMemory(n-nRet);
+  return nRet;
+#else
+  return SQLITE_OK;
+#endif
+}
+
+/*
+** State information local to the memory allocation subsystem.
+*/
+static struct {
+  sqlite3_mutex *mutex;         /* Mutex to serialize access */
+
+  /*
+  ** The alarm callback and its arguments.  The mem0.mutex lock will
+  ** be held while the callback is running.  Recursive calls into
+  ** the memory subsystem are allowed, but no new callbacks will be
+  ** issued.  The alarmBusy variable is set to prevent recursive
+  ** callbacks.
+  */
+  sqlite3_int64 alarmThreshold;
+  void (*alarmCallback)(void*, sqlite3_int64,int);
+  void *alarmArg;
+  int alarmBusy;
+
+  /*
+  ** Pointers to the end of sqlite3Config.pScratch and
+  ** sqlite3Config.pPage to a block of memory that records
+  ** which pages are available.
+  */
+  u32 *aScratchFree;
+  u32 *aPageFree;
+
+  /* Number of free pages for scratch and page-cache memory */
+  u32 nScratchFree;
+  u32 nPageFree;
+} mem0;
+
+/*
+** Initialize the memory allocation subsystem.
+*/
+int sqlite3MallocInit(void){
+  if( sqlite3Config.m.xMalloc==0 ){
+    sqlite3MemSetDefault();
+  }
+  memset(&mem0, 0, sizeof(mem0));
+  if( sqlite3Config.bCoreMutex ){
+    mem0.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
+  }
+  if( sqlite3Config.pScratch && sqlite3Config.szScratch>=100
+      && sqlite3Config.nScratch>=0 ){
+    int i;
+    sqlite3Config.szScratch -= 4;
+    mem0.aScratchFree = (u32*)&((char*)sqlite3Config.pScratch)
+                  [sqlite3Config.szScratch*sqlite3Config.nScratch];
+    for(i=0; i<sqlite3Config.nScratch; i++){ mem0.aScratchFree[i] = i; }
+    mem0.nScratchFree = sqlite3Config.nScratch;
+  }else{
+    sqlite3Config.pScratch = 0;
+    sqlite3Config.szScratch = 0;
+  }
+  if( sqlite3Config.pPage && sqlite3Config.szPage>=512
+      && sqlite3Config.nPage>=1 ){
+    int i;
+    int overhead;
+    int sz = sqlite3Config.szPage;
+    int n = sqlite3Config.nPage;
+    overhead = (4*n + sz - 1)/sz;
+    sqlite3Config.nPage -= overhead;
+    mem0.aPageFree = (u32*)&((char*)sqlite3Config.pPage)
+                  [sqlite3Config.szPage*sqlite3Config.nPage];
+    for(i=0; i<sqlite3Config.nPage; i++){ mem0.aPageFree[i] = i; }
+    mem0.nPageFree = sqlite3Config.nPage;
+  }else{
+    sqlite3Config.pPage = 0;
+    sqlite3Config.szPage = 0;
+  }
+  return sqlite3Config.m.xInit(sqlite3Config.m.pAppData);
+}
+
+/*
+** Deinitialize the memory allocation subsystem.
+*/
+void sqlite3MallocEnd(void){
+  sqlite3Config.m.xShutdown(sqlite3Config.m.pAppData);
+  memset(&mem0, 0, sizeof(mem0));
+}
+
+/*
+** Return the amount of memory currently checked out.
+*/
+sqlite3_int64 sqlite3_memory_used(void){
+  int n, mx;
+  sqlite3_int64 res;
+  sqlite3_status(SQLITE_STATUS_MEMORY_USED, &n, &mx, 0);
+  res = (sqlite3_int64)n;  /* Work around bug in Borland C. Ticket #3216 */
+  return res;
+}
+
+/*
+** Return the maximum amount of memory that has ever been
+** checked out since either the beginning of this process
+** or since the most recent reset.
+*/
+sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
+  int n, mx;
+  sqlite3_int64 res;
+  sqlite3_status(SQLITE_STATUS_MEMORY_USED, &n, &mx, resetFlag);
+  res = (sqlite3_int64)mx;  /* Work around bug in Borland C. Ticket #3216 */
+  return res;
+}
+
+/*
+** Change the alarm callback
+*/
+int sqlite3_memory_alarm(
+  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
+  void *pArg,
+  sqlite3_int64 iThreshold
+){
+  sqlite3_mutex_enter(mem0.mutex);
+  mem0.alarmCallback = xCallback;
+  mem0.alarmArg = pArg;
+  mem0.alarmThreshold = iThreshold;
+  sqlite3_mutex_leave(mem0.mutex);
+  return SQLITE_OK;
+}
+
+/*
+** Trigger the alarm 
+*/
+static void sqlite3MallocAlarm(int nByte){
+  void (*xCallback)(void*,sqlite3_int64,int);
+  sqlite3_int64 nowUsed;
+  void *pArg;
+  if( mem0.alarmCallback==0 || mem0.alarmBusy  ) return;
+  mem0.alarmBusy = 1;
+  xCallback = mem0.alarmCallback;
+  nowUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
+  pArg = mem0.alarmArg;
+  sqlite3_mutex_leave(mem0.mutex);
+  xCallback(pArg, nowUsed, nByte);
+  sqlite3_mutex_enter(mem0.mutex);
+  mem0.alarmBusy = 0;
+}
+
+/*
+** Do a memory allocation with statistics and alarms.  Assume the
+** lock is already held.
+*/
+static int mallocWithAlarm(int n, void **pp){
+  int nFull;
+  void *p;
+  assert( sqlite3_mutex_held(mem0.mutex) );
+  nFull = sqlite3Config.m.xRoundup(n);
+  sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, n);
+  if( mem0.alarmCallback!=0 ){
+    int nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
+    if( nUsed+nFull >= mem0.alarmThreshold ){
+      sqlite3MallocAlarm(nFull);
+    }
+  }
+  p = sqlite3Config.m.xMalloc(nFull);
+  if( p==0 && mem0.alarmCallback ){
+    sqlite3MallocAlarm(nFull);
+    p = sqlite3Config.m.xMalloc(nFull);
+  }
+  if( p ){
+    nFull = sqlite3MallocSize(p);
+    sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, nFull);
+  }
+  *pp = p;
+  return nFull;
+}
+
+/*
+** Allocate memory.  This routine is like sqlite3_malloc() except that it
+** assumes the memory subsystem has already been initialized.
+*/
+void *sqlite3Malloc(int n){
+  void *p;
+  if( n<=0 ){
+    p = 0;
+  }else if( sqlite3Config.bMemstat ){
+    sqlite3_mutex_enter(mem0.mutex);
+    mallocWithAlarm(n, &p);
+    sqlite3_mutex_leave(mem0.mutex);
+  }else{
+    p = sqlite3Config.m.xMalloc(n);
+  }
+  return p;
+}
+
+/*
+** This version of the memory allocation is for use by the application.
+** First make sure the memory subsystem is initialized, then do the
+** allocation.
+*/
+void *sqlite3_malloc(int n){
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return sqlite3Malloc(n);
+}
+
+/*
+** Each thread may only have a single outstanding allocation from
+** xScratchMalloc().  We verify this constraint in the single-threaded
+** case by setting scratchAllocOut to 1 when an allocation
+** is outstanding clearing it when the allocation is freed.
+*/
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+static int scratchAllocOut = 0;
+#endif
+
+
+/*
+** Allocate memory that is to be used and released right away.
+** This routine is similar to alloca() in that it is not intended
+** for situations where the memory might be held long-term.  This
+** routine is intended to get memory to old large transient data
+** structures that would not normally fit on the stack of an
+** embedded processor.
+*/
+void *sqlite3ScratchMalloc(int n){
+  void *p;
+  assert( n>0 );
+
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+  /* Verify that no more than one scratch allocation per thread
+  ** is outstanding at one time.  (This is only checked in the
+  ** single-threaded case since checking in the multi-threaded case
+  ** would be much more complicated.) */
+  assert( scratchAllocOut==0 );
+#endif
+
+  if( sqlite3Config.szScratch<n ){
+    goto scratch_overflow;
+  }else{  
+    sqlite3_mutex_enter(mem0.mutex);
+    if( mem0.nScratchFree==0 ){
+      sqlite3_mutex_leave(mem0.mutex);
+      goto scratch_overflow;
+    }else{
+      int i;
+      i = mem0.aScratchFree[--mem0.nScratchFree];
+      sqlite3_mutex_leave(mem0.mutex);
+      i *= sqlite3Config.szScratch;
+      sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, 1);
+      sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n);
+      p = (void*)&((char*)sqlite3Config.pScratch)[i];
+    }
+  }
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+  scratchAllocOut = p!=0;
+#endif
+
+  return p;
+
+scratch_overflow:
+  if( sqlite3Config.bMemstat ){
+    sqlite3_mutex_enter(mem0.mutex);
+    sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n);
+    n = mallocWithAlarm(n, &p);
+    if( p ) sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_OVERFLOW, n);
+    sqlite3_mutex_leave(mem0.mutex);
+  }else{
+    p = sqlite3Config.m.xMalloc(n);
+  }
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+  scratchAllocOut = p!=0;
+#endif
+  return p;    
+}
+void sqlite3ScratchFree(void *p){
+  if( p ){
+
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+    /* Verify that no more than one scratch allocation per thread
+    ** is outstanding at one time.  (This is only checked in the
+    ** single-threaded case since checking in the multi-threaded case
+    ** would be much more complicated.) */
+    assert( scratchAllocOut==1 );
+    scratchAllocOut = 0;
+#endif
+
+    if( sqlite3Config.pScratch==0
+           || p<sqlite3Config.pScratch
+           || p>=(void*)mem0.aScratchFree ){
+      if( sqlite3Config.bMemstat ){
+        int iSize = sqlite3MallocSize(p);
+        sqlite3_mutex_enter(mem0.mutex);
+        sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_OVERFLOW, -iSize);
+        sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, -iSize);
+        sqlite3Config.m.xFree(p);
+        sqlite3_mutex_leave(mem0.mutex);
+      }else{
+        sqlite3Config.m.xFree(p);
+      }
+    }else{
+      int i;
+      i = (u8 *)p - (u8 *)sqlite3Config.pScratch;
+      i /= sqlite3Config.szScratch;
+      assert( i>=0 && i<sqlite3Config.nScratch );
+      sqlite3_mutex_enter(mem0.mutex);
+      assert( mem0.nScratchFree<sqlite3Config.nScratch );
+      mem0.aScratchFree[mem0.nScratchFree++] = i;
+      sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, -1);
+      sqlite3_mutex_leave(mem0.mutex);
+    }
+  }
+}
+
+/*
+** Allocate memory to be used by the page cache.  Make use of the
+** memory buffer provided by SQLITE_CONFIG_PAGECACHE if there is one
+** and that memory is of the right size and is not completely
+** consumed.  Otherwise, failover to sqlite3Malloc().
+*/
+void *sqlite3PageMalloc(int n){
+  void *p;
+  assert( n>0 );
+  assert( (n & (n-1))==0 );
+  assert( n>=512 && n<=32768 );
+
+  if( sqlite3Config.szPage<n ){
+    goto page_overflow;
+  }else{  
+    sqlite3_mutex_enter(mem0.mutex);
+    if( mem0.nPageFree==0 ){
+      sqlite3_mutex_leave(mem0.mutex);
+      goto page_overflow;
+    }else{
+      int i;
+      i = mem0.aPageFree[--mem0.nPageFree];
+      sqlite3_mutex_leave(mem0.mutex);
+      i *= sqlite3Config.szPage;
+      sqlite3StatusSet(SQLITE_STATUS_PAGECACHE_SIZE, n);
+      sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, 1);
+      p = (void*)&((char*)sqlite3Config.pPage)[i];
+    }
+  }
+  return p;
+
+page_overflow:
+  if( sqlite3Config.bMemstat ){
+    sqlite3_mutex_enter(mem0.mutex);
+    sqlite3StatusSet(SQLITE_STATUS_PAGECACHE_SIZE, n);
+    n = mallocWithAlarm(n, &p);
+    if( p ) sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, n);
+    sqlite3_mutex_leave(mem0.mutex);
+  }else{
+    p = sqlite3Config.m.xMalloc(n);
+  }
+  return p;    
+}
+void sqlite3PageFree(void *p){
+  if( p ){
+    if( sqlite3Config.pPage==0
+           || p<sqlite3Config.pPage
+           || p>=(void*)mem0.aPageFree ){
+      /* In this case, the page allocation was obtained from a regular 
+      ** call to sqlite3_mem_methods.xMalloc() (a page-cache-memory 
+      ** "overflow"). Free the block with sqlite3_mem_methods.xFree().
+      */
+      if( sqlite3Config.bMemstat ){
+        int iSize = sqlite3MallocSize(p);
+        sqlite3_mutex_enter(mem0.mutex);
+        sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, -iSize);
+        sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, -iSize);
+        sqlite3Config.m.xFree(p);
+        sqlite3_mutex_leave(mem0.mutex);
+      }else{
+        sqlite3Config.m.xFree(p);
+      }
+    }else{
+      /* The page allocation was allocated from the sqlite3Config.pPage
+      ** buffer. In this case all that is add the index of the page in
+      ** the sqlite3Config.pPage array to the set of free indexes stored
+      ** in the mem0.aPageFree[] array.
+      */
+      int i;
+      i = (u8 *)p - (u8 *)sqlite3Config.pPage;
+      i /= sqlite3Config.szPage;
+      assert( i>=0 && i<sqlite3Config.nPage );
+      sqlite3_mutex_enter(mem0.mutex);
+      assert( mem0.nPageFree<sqlite3Config.nPage );
+      mem0.aPageFree[mem0.nPageFree++] = i;
+      sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, -1);
+      sqlite3_mutex_leave(mem0.mutex);
+#if !defined(NDEBUG) && 0
+      /* Assert that a duplicate was not just inserted into aPageFree[]. */
+      for(i=0; i<mem0.nPageFree-1; i++){
+        assert( mem0.aPageFree[i]!=mem0.aPageFree[mem0.nPageFree-1] );
+      }
+#endif
+    }
+  }
+}
+
+/*
+** TRUE if p is a lookaside memory allocation from db
+*/
+static int isLookaside(sqlite3 *db, void *p){
+  return db && p && p>=db->lookaside.pStart && p<db->lookaside.pEnd;
+}
+
+/*
+** Return the size of a memory allocation previously obtained from
+** sqlite3Malloc() or sqlite3_malloc().
+*/
+int sqlite3MallocSize(void *p){
+  return sqlite3Config.m.xSize(p);
+}
+int sqlite3DbMallocSize(sqlite3 *db, void *p){
+  if( isLookaside(db, p) ){
+    return db->lookaside.sz;
+  }else{
+    return sqlite3Config.m.xSize(p);
+  }
+}
+
+/*
+** Free memory previously obtained from sqlite3Malloc().
+*/
+void sqlite3_free(void *p){
+  if( p==0 ) return;
+  if( sqlite3Config.bMemstat ){
+    sqlite3_mutex_enter(mem0.mutex);
+    sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, -sqlite3MallocSize(p));
+    sqlite3Config.m.xFree(p);
+    sqlite3_mutex_leave(mem0.mutex);
+  }else{
+    sqlite3Config.m.xFree(p);
+  }
+}
+
+/*
+** Free memory that might be associated with a particular database
+** connection.
+*/
+void sqlite3DbFree(sqlite3 *db, void *p){
+  if( isLookaside(db, p) ){
+    LookasideSlot *pBuf = (LookasideSlot*)p;
+    pBuf->pNext = db->lookaside.pFree;
+    db->lookaside.pFree = pBuf;
+    db->lookaside.nOut--;
+  }else{
+    sqlite3_free(p);
+  }
+}
+
+/*
+** Change the size of an existing memory allocation
+*/
+void *sqlite3Realloc(void *pOld, int nBytes){
+  int nOld, nNew;
+  void *pNew;
+  if( pOld==0 ){
+    return sqlite3Malloc(nBytes);
+  }
+  if( nBytes<=0 ){
+    sqlite3_free(pOld);
+    return 0;
+  }
+  nOld = sqlite3MallocSize(pOld);
+  if( sqlite3Config.bMemstat ){
+    sqlite3_mutex_enter(mem0.mutex);
+    sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, nBytes);
+    nNew = sqlite3Config.m.xRoundup(nBytes);
+    if( nOld==nNew ){
+      pNew = pOld;
+    }else{
+      if( sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED)+nNew-nOld >= 
+            mem0.alarmThreshold ){
+        sqlite3MallocAlarm(nNew-nOld);
+      }
+      pNew = sqlite3Config.m.xRealloc(pOld, nNew);
+      if( pNew==0 && mem0.alarmCallback ){
+        sqlite3MallocAlarm(nBytes);
+        pNew = sqlite3Config.m.xRealloc(pOld, nNew);
+      }
+      if( pNew ){
+        nNew = sqlite3MallocSize(pNew);
+        sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, nNew-nOld);
+      }
+    }
+    sqlite3_mutex_leave(mem0.mutex);
+  }else{
+    pNew = sqlite3Config.m.xRealloc(pOld, nBytes);
+  }
+  return pNew;
+}
+
+/*
+** The public interface to sqlite3Realloc.  Make sure that the memory
+** subsystem is initialized prior to invoking sqliteRealloc.
+*/
+void *sqlite3_realloc(void *pOld, int n){
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return sqlite3Realloc(pOld, n);
+}
+
+
+/*
+** Allocate and zero memory.
+*/ 
+void *sqlite3MallocZero(int n){
+  void *p = sqlite3Malloc(n);
+  if( p ){
+    memset(p, 0, n);
+  }
+  return p;
+}
+
+/*
+** Allocate and zero memory.  If the allocation fails, make
+** the mallocFailed flag in the connection pointer.
+*/
+void *sqlite3DbMallocZero(sqlite3 *db, int n){
+  void *p = sqlite3DbMallocRaw(db, n);
+  if( p ){
+    memset(p, 0, n);
+  }
+  return p;
+}
+
+/*
+** Allocate and zero memory.  If the allocation fails, make
+** the mallocFailed flag in the connection pointer.
+*/
+void *sqlite3DbMallocRaw(sqlite3 *db, int n){
+  void *p;
+  if( db ){
+    LookasideSlot *pBuf;
+    if( db->mallocFailed ){
+      return 0;
+    }
+    if( db->lookaside.bEnabled && n<=db->lookaside.sz
+         && (pBuf = db->lookaside.pFree)!=0 ){
+      db->lookaside.pFree = pBuf->pNext;
+      db->lookaside.nOut++;
+      if( db->lookaside.nOut>db->lookaside.mxOut ){
+        db->lookaside.mxOut = db->lookaside.nOut;
+      }
+      return (void*)pBuf;
+    }
+  }
+  p = sqlite3Malloc(n);
+  if( !p && db ){
+    db->mallocFailed = 1;
+  }
+  return p;
+}
+
+/*
+** Resize the block of memory pointed to by p to n bytes. If the
+** resize fails, set the mallocFailed flag in the connection object.
+*/
+void *sqlite3DbRealloc(sqlite3 *db, void *p, int n){
+  void *pNew = 0;
+  if( db->mallocFailed==0 ){
+    if( p==0 ){
+      return sqlite3DbMallocRaw(db, n);
+    }
+    if( isLookaside(db, p) ){
+      if( n<=db->lookaside.sz ){
+        return p;
+      }
+      pNew = sqlite3DbMallocRaw(db, n);
+      if( pNew ){
+        memcpy(pNew, p, db->lookaside.sz);
+        sqlite3DbFree(db, p);
+      }
+    }else{
+      pNew = sqlite3_realloc(p, n);
+      if( !pNew ){
+        db->mallocFailed = 1;
+      }
+    }
+  }
+  return pNew;
+}
+
+/*
+** Attempt to reallocate p.  If the reallocation fails, then free p
+** and set the mallocFailed flag in the database connection.
+*/
+void *sqlite3DbReallocOrFree(sqlite3 *db, void *p, int n){
+  void *pNew;
+  pNew = sqlite3DbRealloc(db, p, n);
+  if( !pNew ){
+    sqlite3DbFree(db, p);
+  }
+  return pNew;
+}
+
+/*
+** Make a copy of a string in memory obtained from sqliteMalloc(). These 
+** functions call sqlite3MallocRaw() directly instead of sqliteMalloc(). This
+** is because when memory debugging is turned on, these two functions are 
+** called via macros that record the current file and line number in the
+** ThreadData structure.
+*/
+char *sqlite3DbStrDup(sqlite3 *db, const char *z){
+  char *zNew;
+  size_t n;
+  if( z==0 ){
+    return 0;
+  }
+  n = strlen(z)+1;
+  assert( (n&0x7fffffff)==n );
+  zNew = sqlite3DbMallocRaw(db, (int)n);
+  if( zNew ){
+    memcpy(zNew, z, n);
+  }
+  return zNew;
+}
+char *sqlite3DbStrNDup(sqlite3 *db, const char *z, int n){
+  char *zNew;
+  if( z==0 ){
+    return 0;
+  }
+  assert( (n&0x7fffffff)==n );
+  zNew = sqlite3DbMallocRaw(db, n+1);
+  if( zNew ){
+    memcpy(zNew, z, n);
+    zNew[n] = 0;
+  }
+  return zNew;
+}
+
+/*
+** Create a string from the zFromat argument and the va_list that follows.
+** Store the string in memory obtained from sqliteMalloc() and make *pz
+** point to that string.
+*/
+void sqlite3SetString(char **pz, sqlite3 *db, const char *zFormat, ...){
+  va_list ap;
+  char *z;
+
+  va_start(ap, zFormat);
+  z = sqlite3VMPrintf(db, zFormat, ap);
+  va_end(ap);
+  sqlite3DbFree(db, *pz);
+  *pz = z;
+}
+
+
+/*
+** This function must be called before exiting any API function (i.e. 
+** returning control to the user) that has called sqlite3_malloc or
+** sqlite3_realloc.
+**
+** The returned value is normally a copy of the second argument to this
+** function. However, if a malloc() failure has occured since the previous
+** invocation SQLITE_NOMEM is returned instead. 
+**
+** If the first argument, db, is not NULL and a malloc() error has occured,
+** then the connection error-code (the value returned by sqlite3_errcode())
+** is set to SQLITE_NOMEM.
+*/
+int sqlite3ApiExit(sqlite3* db, int rc){
+  /* If the db handle is not NULL, then we must hold the connection handle
+  ** mutex here. Otherwise the read (and possible write) of db->mallocFailed 
+  ** is unsafe, as is the call to sqlite3Error().
+  */
+  assert( !db || sqlite3_mutex_held(db->mutex) );
+  if( db && db->mallocFailed ){
+    sqlite3Error(db, SQLITE_NOMEM, 0);
+    db->mallocFailed = 0;
+    rc = SQLITE_NOMEM;
+  }
+  return rc & (db ? db->errMask : 0xff);
+}
diff --git a/third_party/sqlite/src/md5.c b/third_party/sqlite/src/md5.c
new file mode 100755
index 0000000..a6b9abb
--- /dev/null
+++ b/third_party/sqlite/src/md5.c
@@ -0,0 +1,389 @@
+/*
+** SQLite uses this code for testing only.  It is not a part of
+** the SQLite library.  This file implements two new TCL commands
+** "md5" and "md5file" that compute md5 checksums on arbitrary text
+** and on complete files.  These commands are used by the "testfixture"
+** program to help verify the correct operation of the SQLite library.
+**
+** The original use of these TCL commands was to test the ROLLBACK
+** feature of SQLite.  First compute the MD5-checksum of the database.
+** Then make some changes but rollback the changes rather than commit
+** them.  Compute a second MD5-checksum of the file and verify that the
+** two checksums are the same.  Such is the original use of this code.
+** New uses may have been added since this comment was written.
+**
+** $Id: md5.c,v 1.17 2008/05/16 04:51:55 danielk1977 Exp $
+*/
+/*
+ * This code implements the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest.  This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ *
+ * To compute the message digest of a chunk of bytes, declare an
+ * MD5Context structure, pass it to MD5Init, call MD5Update as
+ * needed on buffers full of bytes, and then call MD5Final, which
+ * will fill a supplied 16-byte array with the digest.
+ */
+#include <tcl.h>
+#include <string.h>
+#include "sqlite3.h"
+
+/*
+ * If compiled on a machine that doesn't have a 32-bit integer,
+ * you just set "uint32" to the appropriate datatype for an
+ * unsigned 32-bit integer.  For example:
+ *
+ *       cc -Duint32='unsigned long' md5.c
+ *
+ */
+#ifndef uint32
+#  define uint32 unsigned int
+#endif
+
+struct Context {
+  uint32 buf[4];
+  uint32 bits[2];
+  unsigned char in[64];
+};
+typedef char MD5Context[88];
+
+/*
+ * Note: this code is harmless on little-endian machines.
+ */
+static void byteReverse (unsigned char *buf, unsigned longs){
+        uint32 t;
+        do {
+                t = (uint32)((unsigned)buf[3]<<8 | buf[2]) << 16 |
+                            ((unsigned)buf[1]<<8 | buf[0]);
+                *(uint32 *)buf = t;
+                buf += 4;
+        } while (--longs);
+}
+/* The four core functions - F1 is optimized somewhat */
+
+/* #define F1(x, y, z) (x & y | ~x & z) */
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+/* This is the central step in the MD5 algorithm. */
+#define MD5STEP(f, w, x, y, z, data, s) \
+        ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
+
+/*
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data.  MD5Update blocks
+ * the data and converts bytes into longwords for this routine.
+ */
+static void MD5Transform(uint32 buf[4], const uint32 in[16]){
+        register uint32 a, b, c, d;
+
+        a = buf[0];
+        b = buf[1];
+        c = buf[2];
+        d = buf[3];
+
+        MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478,  7);
+        MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
+        MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
+        MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
+        MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf,  7);
+        MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
+        MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
+        MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
+        MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8,  7);
+        MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
+        MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
+        MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
+        MD5STEP(F1, a, b, c, d, in[12]+0x6b901122,  7);
+        MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
+        MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
+        MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);
+
+        MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562,  5);
+        MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340,  9);
+        MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
+        MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
+        MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d,  5);
+        MD5STEP(F2, d, a, b, c, in[10]+0x02441453,  9);
+        MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
+        MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
+        MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6,  5);
+        MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6,  9);
+        MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
+        MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
+        MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905,  5);
+        MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8,  9);
+        MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
+        MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);
+
+        MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942,  4);
+        MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
+        MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
+        MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
+        MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44,  4);
+        MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
+        MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
+        MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
+        MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6,  4);
+        MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
+        MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
+        MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
+        MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039,  4);
+        MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
+        MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
+        MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);
+
+        MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244,  6);
+        MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
+        MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
+        MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
+        MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3,  6);
+        MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
+        MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
+        MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
+        MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f,  6);
+        MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
+        MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
+        MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
+        MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82,  6);
+        MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
+        MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
+        MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);
+
+        buf[0] += a;
+        buf[1] += b;
+        buf[2] += c;
+        buf[3] += d;
+}
+
+/*
+ * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
+ * initialization constants.
+ */
+static void MD5Init(MD5Context *pCtx){
+        struct Context *ctx = (struct Context *)pCtx;
+        ctx->buf[0] = 0x67452301;
+        ctx->buf[1] = 0xefcdab89;
+        ctx->buf[2] = 0x98badcfe;
+        ctx->buf[3] = 0x10325476;
+        ctx->bits[0] = 0;
+        ctx->bits[1] = 0;
+}
+
+/*
+ * Update context to reflect the concatenation of another buffer full
+ * of bytes.
+ */
+static 
+void MD5Update(MD5Context *pCtx, const unsigned char *buf, unsigned int len){
+        struct Context *ctx = (struct Context *)pCtx;
+        uint32 t;
+
+        /* Update bitcount */
+
+        t = ctx->bits[0];
+        if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
+                ctx->bits[1]++; /* Carry from low to high */
+        ctx->bits[1] += len >> 29;
+
+        t = (t >> 3) & 0x3f;    /* Bytes already in shsInfo->data */
+
+        /* Handle any leading odd-sized chunks */
+
+        if ( t ) {
+                unsigned char *p = (unsigned char *)ctx->in + t;
+
+                t = 64-t;
+                if (len < t) {
+                        memcpy(p, buf, len);
+                        return;
+                }
+                memcpy(p, buf, t);
+                byteReverse(ctx->in, 16);
+                MD5Transform(ctx->buf, (uint32 *)ctx->in);
+                buf += t;
+                len -= t;
+        }
+
+        /* Process data in 64-byte chunks */
+
+        while (len >= 64) {
+                memcpy(ctx->in, buf, 64);
+                byteReverse(ctx->in, 16);
+                MD5Transform(ctx->buf, (uint32 *)ctx->in);
+                buf += 64;
+                len -= 64;
+        }
+
+        /* Handle any remaining bytes of data. */
+
+        memcpy(ctx->in, buf, len);
+}
+
+/*
+ * Final wrapup - pad to 64-byte boundary with the bit pattern 
+ * 1 0* (64-bit count of bits processed, MSB-first)
+ */
+static void MD5Final(unsigned char digest[16], MD5Context *pCtx){
+        struct Context *ctx = (struct Context *)pCtx;
+        unsigned count;
+        unsigned char *p;
+
+        /* Compute number of bytes mod 64 */
+        count = (ctx->bits[0] >> 3) & 0x3F;
+
+        /* Set the first char of padding to 0x80.  This is safe since there is
+           always at least one byte free */
+        p = ctx->in + count;
+        *p++ = 0x80;
+
+        /* Bytes of padding needed to make 64 bytes */
+        count = 64 - 1 - count;
+
+        /* Pad out to 56 mod 64 */
+        if (count < 8) {
+                /* Two lots of padding:  Pad the first block to 64 bytes */
+                memset(p, 0, count);
+                byteReverse(ctx->in, 16);
+                MD5Transform(ctx->buf, (uint32 *)ctx->in);
+
+                /* Now fill the next block with 56 bytes */
+                memset(ctx->in, 0, 56);
+        } else {
+                /* Pad block to 56 bytes */
+                memset(p, 0, count-8);
+        }
+        byteReverse(ctx->in, 14);
+
+        /* Append length in bits and transform */
+        ((uint32 *)ctx->in)[ 14 ] = ctx->bits[0];
+        ((uint32 *)ctx->in)[ 15 ] = ctx->bits[1];
+
+        MD5Transform(ctx->buf, (uint32 *)ctx->in);
+        byteReverse((unsigned char *)ctx->buf, 4);
+        memcpy(digest, ctx->buf, 16);
+        memset(ctx, 0, sizeof(ctx));    /* In case it's sensitive */
+}
+
+/*
+** Convert a digest into base-16.  digest should be declared as
+** "unsigned char digest[16]" in the calling function.  The MD5
+** digest is stored in the first 16 bytes.  zBuf should
+** be "char zBuf[33]".
+*/
+static void DigestToBase16(unsigned char *digest, char *zBuf){
+  static char const zEncode[] = "0123456789abcdef";
+  int i, j;
+
+  for(j=i=0; i<16; i++){
+    int a = digest[i];
+    zBuf[j++] = zEncode[(a>>4)&0xf];
+    zBuf[j++] = zEncode[a & 0xf];
+  }
+  zBuf[j] = 0;
+}
+
+/*
+** A TCL command for md5.  The argument is the text to be hashed.  The
+** Result is the hash in base64.  
+*/
+static int md5_cmd(void*cd, Tcl_Interp *interp, int argc, const char **argv){
+  MD5Context ctx;
+  unsigned char digest[16];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0], 
+        " TEXT\"", 0);
+    return TCL_ERROR;
+  }
+  MD5Init(&ctx);
+  MD5Update(&ctx, (unsigned char*)argv[1], (unsigned)strlen(argv[1]));
+  MD5Final(digest, &ctx);
+  DigestToBase16(digest, interp->result);
+  return TCL_OK;
+}
+
+/*
+** A TCL command to take the md5 hash of a file.  The argument is the
+** name of the file.
+*/
+static int md5file_cmd(void*cd, Tcl_Interp*interp, int argc, const char **argv){
+  FILE *in;
+  MD5Context ctx;
+  unsigned char digest[16];
+  char zBuf[10240];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0], 
+        " FILENAME\"", 0);
+    return TCL_ERROR;
+  }
+  in = fopen(argv[1],"rb");
+  if( in==0 ){
+    Tcl_AppendResult(interp,"unable to open file \"", argv[1], 
+         "\" for reading", 0);
+    return TCL_ERROR;
+  }
+  MD5Init(&ctx);
+  for(;;){
+    int n;
+    n = fread(zBuf, 1, sizeof(zBuf), in);
+    if( n<=0 ) break;
+    MD5Update(&ctx, (unsigned char*)zBuf, (unsigned)n);
+  }
+  fclose(in);
+  MD5Final(digest, &ctx);
+  DigestToBase16(digest, interp->result);
+  return TCL_OK;
+}
+
+/*
+** Register the two TCL commands above with the TCL interpreter.
+*/
+int Md5_Init(Tcl_Interp *interp){
+  Tcl_CreateCommand(interp, "md5", (Tcl_CmdProc*)md5_cmd, 0, 0);
+  Tcl_CreateCommand(interp, "md5file", (Tcl_CmdProc*)md5file_cmd, 0, 0);
+  return TCL_OK;
+}
+
+/*
+** During testing, the special md5sum() aggregate function is available.
+** inside SQLite.  The following routines implement that function.
+*/
+static void md5step(sqlite3_context *context, int argc, sqlite3_value **argv){
+  MD5Context *p;
+  int i;
+  if( argc<1 ) return;
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  if( p==0 ) return;
+  if( sqlite3_aggregate_count(context)==1 ){
+    MD5Init(p);
+  }
+  for(i=0; i<argc; i++){
+    const char *zData = (char*)sqlite3_value_text(argv[i]);
+    if( zData ){
+      MD5Update(p, (unsigned char*)zData, strlen(zData));
+    }
+  }
+}
+static void md5finalize(sqlite3_context *context){
+  MD5Context *p;
+  unsigned char digest[16];
+  char zBuf[33];
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  MD5Final(digest,p);
+  DigestToBase16(digest, zBuf);
+  sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
+}
+void Md5_Register(sqlite3 *db){
+  sqlite3_create_function(db, "md5sum", -1, SQLITE_UTF8, 0, 0, 
+      md5step, md5finalize);
+}
diff --git a/third_party/sqlite/src/mem1.c b/third_party/sqlite/src/mem1.c
new file mode 100755
index 0000000..1a3a68e
--- /dev/null
+++ b/third_party/sqlite/src/mem1.c
@@ -0,0 +1,147 @@
+/*
+** 2007 August 14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains low-level memory allocation drivers for when
+** SQLite will use the standard C-library malloc/realloc/free interface
+** to obtain the memory it needs.
+**
+** This file contains implementations of the low-level memory allocation
+** routines specified in the sqlite3_mem_methods object.
+**
+** $Id: mem1.c,v 1.25 2008/07/25 08:49:00 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** This version of the memory allocator is the default.  It is
+** used when no other memory allocator is specified using compile-time
+** macros.
+*/
+#ifdef SQLITE_SYSTEM_MALLOC
+
+/*
+** Like malloc(), but remember the size of the allocation
+** so that we can find it later using sqlite3MemSize().
+**
+** For this low-level routine, we are guaranteed that nByte>0 because
+** cases of nByte<=0 will be intercepted and dealt with by higher level
+** routines.
+*/
+static void *sqlite3MemMalloc(int nByte){
+  sqlite3_int64 *p;
+  assert( nByte>0 );
+  nByte = (nByte+7)&~7;
+  p = malloc( nByte+8 );
+  if( p ){
+    p[0] = nByte;
+    p++;
+  }
+  return (void *)p;
+}
+
+/*
+** Like free() but works for allocations obtained from sqlite3MemMalloc()
+** or sqlite3MemRealloc().
+**
+** For this low-level routine, we already know that pPrior!=0 since
+** cases where pPrior==0 will have been intecepted and dealt with
+** by higher-level routines.
+*/
+static void sqlite3MemFree(void *pPrior){
+  sqlite3_int64 *p = (sqlite3_int64*)pPrior;
+  assert( pPrior!=0 );
+  p--;
+  free(p);
+}
+
+/*
+** Like realloc().  Resize an allocation previously obtained from
+** sqlite3MemMalloc().
+**
+** For this low-level interface, we know that pPrior!=0.  Cases where
+** pPrior==0 while have been intercepted by higher-level routine and
+** redirected to xMalloc.  Similarly, we know that nByte>0 becauses
+** cases where nByte<=0 will have been intercepted by higher-level
+** routines and redirected to xFree.
+*/
+static void *sqlite3MemRealloc(void *pPrior, int nByte){
+  sqlite3_int64 *p = (sqlite3_int64*)pPrior;
+  assert( pPrior!=0 && nByte>0 );
+  nByte = (nByte+7)&~7;
+  p = (sqlite3_int64*)pPrior;
+  p--;
+  p = realloc(p, nByte+8 );
+  if( p ){
+    p[0] = nByte;
+    p++;
+  }
+  return (void*)p;
+}
+
+/*
+** Report the allocated size of a prior return from xMalloc()
+** or xRealloc().
+*/
+static int sqlite3MemSize(void *pPrior){
+  sqlite3_int64 *p;
+  if( pPrior==0 ) return 0;
+  p = (sqlite3_int64*)pPrior;
+  p--;
+  return p[0];
+}
+
+/*
+** Round up a request size to the next valid allocation size.
+*/
+static int sqlite3MemRoundup(int n){
+  return (n+7) & ~7;
+}
+
+/*
+** Initialize this module.
+*/
+static int sqlite3MemInit(void *NotUsed){
+  return SQLITE_OK;
+}
+
+/*
+** Deinitialize this module.
+*/
+static void sqlite3MemShutdown(void *NotUsed){
+  return;
+}
+
+const sqlite3_mem_methods *sqlite3MemGetDefault(void){
+  static const sqlite3_mem_methods defaultMethods = {
+     sqlite3MemMalloc,
+     sqlite3MemFree,
+     sqlite3MemRealloc,
+     sqlite3MemSize,
+     sqlite3MemRoundup,
+     sqlite3MemInit,
+     sqlite3MemShutdown,
+     0
+  };
+  return &defaultMethods;
+}
+
+/*
+** This routine is the only routine in this file with external linkage.
+**
+** Populate the low-level memory allocation function pointers in
+** sqlite3Config.m with pointers to the routines in this file.
+*/
+void sqlite3MemSetDefault(void){
+  sqlite3_config(SQLITE_CONFIG_MALLOC, sqlite3MemGetDefault());
+}
+
+#endif /* SQLITE_SYSTEM_MALLOC */
diff --git a/third_party/sqlite/src/mem2.c b/third_party/sqlite/src/mem2.c
new file mode 100755
index 0000000..f1425e8
--- /dev/null
+++ b/third_party/sqlite/src/mem2.c
@@ -0,0 +1,443 @@
+/*
+** 2007 August 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains low-level memory allocation drivers for when
+** SQLite will use the standard C-library malloc/realloc/free interface
+** to obtain the memory it needs while adding lots of additional debugging
+** information to each allocation in order to help detect and fix memory
+** leaks and memory usage errors.
+**
+** This file contains implementations of the low-level memory allocation
+** routines specified in the sqlite3_mem_methods object.
+**
+** $Id: mem2.c,v 1.37 2008/07/25 08:49:00 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** This version of the memory allocator is used only if the
+** SQLITE_MEMDEBUG macro is defined
+*/
+#ifdef SQLITE_MEMDEBUG
+
+/*
+** The backtrace functionality is only available with GLIBC
+*/
+#ifdef __GLIBC__
+  extern int backtrace(void**,int);
+  extern void backtrace_symbols_fd(void*const*,int,int);
+#else
+# define backtrace(A,B) 0
+# define backtrace_symbols_fd(A,B,C)
+#endif
+#include <stdio.h>
+
+/*
+** Each memory allocation looks like this:
+**
+**  ------------------------------------------------------------------------
+**  | Title |  backtrace pointers |  MemBlockHdr |  allocation |  EndGuard |
+**  ------------------------------------------------------------------------
+**
+** The application code sees only a pointer to the allocation.  We have
+** to back up from the allocation pointer to find the MemBlockHdr.  The
+** MemBlockHdr tells us the size of the allocation and the number of
+** backtrace pointers.  There is also a guard word at the end of the
+** MemBlockHdr.
+*/
+struct MemBlockHdr {
+  i64 iSize;                          /* Size of this allocation */
+  struct MemBlockHdr *pNext, *pPrev;  /* Linked list of all unfreed memory */
+  char nBacktrace;                    /* Number of backtraces on this alloc */
+  char nBacktraceSlots;               /* Available backtrace slots */
+  short nTitle;                       /* Bytes of title; includes '\0' */
+  int iForeGuard;                     /* Guard word for sanity */
+};
+
+/*
+** Guard words
+*/
+#define FOREGUARD 0x80F5E153
+#define REARGUARD 0xE4676B53
+
+/*
+** Number of malloc size increments to track.
+*/
+#define NCSIZE  1000
+
+/*
+** All of the static variables used by this module are collected
+** into a single structure named "mem".  This is to keep the
+** static variables organized and to reduce namespace pollution
+** when this module is combined with other in the amalgamation.
+*/
+static struct {
+  
+  /*
+  ** Mutex to control access to the memory allocation subsystem.
+  */
+  sqlite3_mutex *mutex;
+
+  /*
+  ** Head and tail of a linked list of all outstanding allocations
+  */
+  struct MemBlockHdr *pFirst;
+  struct MemBlockHdr *pLast;
+  
+  /*
+  ** The number of levels of backtrace to save in new allocations.
+  */
+  int nBacktrace;
+  void (*xBacktrace)(int, int, void **);
+
+  /*
+  ** Title text to insert in front of each block
+  */
+  int nTitle;        /* Bytes of zTitle to save.  Includes '\0' and padding */
+  char zTitle[100];  /* The title text */
+
+  /* 
+  ** sqlite3MallocDisallow() increments the following counter.
+  ** sqlite3MallocAllow() decrements it.
+  */
+  int disallow; /* Do not allow memory allocation */
+
+  /*
+  ** Gather statistics on the sizes of memory allocations.
+  ** nAlloc[i] is the number of allocation attempts of i*8
+  ** bytes.  i==NCSIZE is the number of allocation attempts for
+  ** sizes more than NCSIZE*8 bytes.
+  */
+  int nAlloc[NCSIZE];      /* Total number of allocations */
+  int nCurrent[NCSIZE];    /* Current number of allocations */
+  int mxCurrent[NCSIZE];   /* Highwater mark for nCurrent */
+
+} mem;
+
+
+/*
+** Adjust memory usage statistics
+*/
+static void adjustStats(int iSize, int increment){
+  int i = ((iSize+7)&~7)/8;
+  if( i>NCSIZE-1 ){
+    i = NCSIZE - 1;
+  }
+  if( increment>0 ){
+    mem.nAlloc[i]++;
+    mem.nCurrent[i]++;
+    if( mem.nCurrent[i]>mem.mxCurrent[i] ){
+      mem.mxCurrent[i] = mem.nCurrent[i];
+    }
+  }else{
+    mem.nCurrent[i]--;
+    assert( mem.nCurrent[i]>=0 );
+  }
+}
+
+/*
+** Given an allocation, find the MemBlockHdr for that allocation.
+**
+** This routine checks the guards at either end of the allocation and
+** if they are incorrect it asserts.
+*/
+static struct MemBlockHdr *sqlite3MemsysGetHeader(void *pAllocation){
+  struct MemBlockHdr *p;
+  int *pInt;
+  u8 *pU8;
+  int nReserve;
+
+  p = (struct MemBlockHdr*)pAllocation;
+  p--;
+  assert( p->iForeGuard==FOREGUARD );
+  nReserve = (p->iSize+7)&~7;
+  pInt = (int*)pAllocation;
+  pU8 = (u8*)pAllocation;
+  assert( pInt[nReserve/sizeof(int)]==REARGUARD );
+  assert( (nReserve-0)<=p->iSize || pU8[nReserve-1]==0x65 );
+  assert( (nReserve-1)<=p->iSize || pU8[nReserve-2]==0x65 );
+  assert( (nReserve-2)<=p->iSize || pU8[nReserve-3]==0x65 );
+  return p;
+}
+
+/*
+** Return the number of bytes currently allocated at address p.
+*/
+static int sqlite3MemSize(void *p){
+  struct MemBlockHdr *pHdr;
+  if( !p ){
+    return 0;
+  }
+  pHdr = sqlite3MemsysGetHeader(p);
+  return pHdr->iSize;
+}
+
+/*
+** Initialize the memory allocation subsystem.
+*/
+static int sqlite3MemInit(void *NotUsed){
+  if( !sqlite3Config.bMemstat ){
+    /* If memory status is enabled, then the malloc.c wrapper will already
+    ** hold the STATIC_MEM mutex when the routines here are invoked. */
+    mem.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Deinitialize the memory allocation subsystem.
+*/
+static void sqlite3MemShutdown(void *NotUsed){
+  mem.mutex = 0;
+}
+
+/*
+** Round up a request size to the next valid allocation size.
+*/
+static int sqlite3MemRoundup(int n){
+  return (n+7) & ~7;
+}
+
+/*
+** Allocate nByte bytes of memory.
+*/
+static void *sqlite3MemMalloc(int nByte){
+  struct MemBlockHdr *pHdr;
+  void **pBt;
+  char *z;
+  int *pInt;
+  void *p = 0;
+  int totalSize;
+  int nReserve;
+  sqlite3_mutex_enter(mem.mutex);
+  assert( mem.disallow==0 );
+  nReserve = (nByte+7)&~7;
+  totalSize = nReserve + sizeof(*pHdr) + sizeof(int) +
+               mem.nBacktrace*sizeof(void*) + mem.nTitle;
+  p = malloc(totalSize);
+  if( p ){
+    z = p;
+    pBt = (void**)&z[mem.nTitle];
+    pHdr = (struct MemBlockHdr*)&pBt[mem.nBacktrace];
+    pHdr->pNext = 0;
+    pHdr->pPrev = mem.pLast;
+    if( mem.pLast ){
+      mem.pLast->pNext = pHdr;
+    }else{
+      mem.pFirst = pHdr;
+    }
+    mem.pLast = pHdr;
+    pHdr->iForeGuard = FOREGUARD;
+    pHdr->nBacktraceSlots = mem.nBacktrace;
+    pHdr->nTitle = mem.nTitle;
+    if( mem.nBacktrace ){
+      void *aAddr[40];
+      pHdr->nBacktrace = backtrace(aAddr, mem.nBacktrace+1)-1;
+      memcpy(pBt, &aAddr[1], pHdr->nBacktrace*sizeof(void*));
+      if( mem.xBacktrace ){
+        mem.xBacktrace(nByte, pHdr->nBacktrace-1, &aAddr[1]);
+      }
+    }else{
+      pHdr->nBacktrace = 0;
+    }
+    if( mem.nTitle ){
+      memcpy(z, mem.zTitle, mem.nTitle);
+    }
+    pHdr->iSize = nByte;
+    adjustStats(nByte, +1);
+    pInt = (int*)&pHdr[1];
+    pInt[nReserve/sizeof(int)] = REARGUARD;
+    memset(pInt, 0x65, nReserve);
+    p = (void*)pInt;
+  }
+  sqlite3_mutex_leave(mem.mutex);
+  return p; 
+}
+
+/*
+** Free memory.
+*/
+static void sqlite3MemFree(void *pPrior){
+  struct MemBlockHdr *pHdr;
+  void **pBt;
+  char *z;
+  assert( sqlite3Config.bMemstat || mem.mutex!=0 );
+  pHdr = sqlite3MemsysGetHeader(pPrior);
+  pBt = (void**)pHdr;
+  pBt -= pHdr->nBacktraceSlots;
+  sqlite3_mutex_enter(mem.mutex);
+  if( pHdr->pPrev ){
+    assert( pHdr->pPrev->pNext==pHdr );
+    pHdr->pPrev->pNext = pHdr->pNext;
+  }else{
+    assert( mem.pFirst==pHdr );
+    mem.pFirst = pHdr->pNext;
+  }
+  if( pHdr->pNext ){
+    assert( pHdr->pNext->pPrev==pHdr );
+    pHdr->pNext->pPrev = pHdr->pPrev;
+  }else{
+    assert( mem.pLast==pHdr );
+    mem.pLast = pHdr->pPrev;
+  }
+  z = (char*)pBt;
+  z -= pHdr->nTitle;
+  adjustStats(pHdr->iSize, -1);
+  memset(z, 0x2b, sizeof(void*)*pHdr->nBacktraceSlots + sizeof(*pHdr) +
+                  pHdr->iSize + sizeof(int) + pHdr->nTitle);
+  free(z);
+  sqlite3_mutex_leave(mem.mutex);  
+}
+
+/*
+** Change the size of an existing memory allocation.
+**
+** For this debugging implementation, we *always* make a copy of the
+** allocation into a new place in memory.  In this way, if the 
+** higher level code is using pointer to the old allocation, it is 
+** much more likely to break and we are much more liking to find
+** the error.
+*/
+static void *sqlite3MemRealloc(void *pPrior, int nByte){
+  struct MemBlockHdr *pOldHdr;
+  void *pNew;
+  assert( mem.disallow==0 );
+  pOldHdr = sqlite3MemsysGetHeader(pPrior);
+  pNew = sqlite3MemMalloc(nByte);
+  if( pNew ){
+    memcpy(pNew, pPrior, nByte<pOldHdr->iSize ? nByte : pOldHdr->iSize);
+    if( nByte>pOldHdr->iSize ){
+      memset(&((char*)pNew)[pOldHdr->iSize], 0x2b, nByte - pOldHdr->iSize);
+    }
+    sqlite3MemFree(pPrior);
+  }
+  return pNew;
+}
+
+
+const sqlite3_mem_methods *sqlite3MemGetDefault(void){
+  static const sqlite3_mem_methods defaultMethods = {
+     sqlite3MemMalloc,
+     sqlite3MemFree,
+     sqlite3MemRealloc,
+     sqlite3MemSize,
+     sqlite3MemRoundup,
+     sqlite3MemInit,
+     sqlite3MemShutdown,
+     0
+  };
+  return &defaultMethods;
+}
+
+/*
+** Populate the low-level memory allocation function pointers in
+** sqlite3Config.m with pointers to the routines in this file.
+*/
+void sqlite3MemSetDefault(void){
+  sqlite3_config(SQLITE_CONFIG_MALLOC, sqlite3MemGetDefault());
+}
+
+/*
+** Set the number of backtrace levels kept for each allocation.
+** A value of zero turns off backtracing.  The number is always rounded
+** up to a multiple of 2.
+*/
+void sqlite3MemdebugBacktrace(int depth){
+  if( depth<0 ){ depth = 0; }
+  if( depth>20 ){ depth = 20; }
+  depth = (depth+1)&0xfe;
+  mem.nBacktrace = depth;
+}
+
+void sqlite3MemdebugBacktraceCallback(void (*xBacktrace)(int, int, void **)){
+  mem.xBacktrace = xBacktrace;
+}
+
+/*
+** Set the title string for subsequent allocations.
+*/
+void sqlite3MemdebugSettitle(const char *zTitle){
+  int n = strlen(zTitle) + 1;
+  sqlite3_mutex_enter(mem.mutex);
+  if( n>=sizeof(mem.zTitle) ) n = sizeof(mem.zTitle)-1;
+  memcpy(mem.zTitle, zTitle, n);
+  mem.zTitle[n] = 0;
+  mem.nTitle = (n+7)&~7;
+  sqlite3_mutex_leave(mem.mutex);
+}
+
+void sqlite3MemdebugSync(){
+  struct MemBlockHdr *pHdr;
+  for(pHdr=mem.pFirst; pHdr; pHdr=pHdr->pNext){
+    void **pBt = (void**)pHdr;
+    pBt -= pHdr->nBacktraceSlots;
+    mem.xBacktrace(pHdr->iSize, pHdr->nBacktrace-1, &pBt[1]);
+  }
+}
+
+/*
+** Open the file indicated and write a log of all unfreed memory 
+** allocations into that log.
+*/
+void sqlite3MemdebugDump(const char *zFilename){
+  FILE *out;
+  struct MemBlockHdr *pHdr;
+  void **pBt;
+  int i;
+  out = fopen(zFilename, "w");
+  if( out==0 ){
+    fprintf(stderr, "** Unable to output memory debug output log: %s **\n",
+                    zFilename);
+    return;
+  }
+  for(pHdr=mem.pFirst; pHdr; pHdr=pHdr->pNext){
+    char *z = (char*)pHdr;
+    z -= pHdr->nBacktraceSlots*sizeof(void*) + pHdr->nTitle;
+    fprintf(out, "**** %lld bytes at %p from %s ****\n", 
+            pHdr->iSize, &pHdr[1], pHdr->nTitle ? z : "???");
+    if( pHdr->nBacktrace ){
+      fflush(out);
+      pBt = (void**)pHdr;
+      pBt -= pHdr->nBacktraceSlots;
+      backtrace_symbols_fd(pBt, pHdr->nBacktrace, fileno(out));
+      fprintf(out, "\n");
+    }
+  }
+  fprintf(out, "COUNTS:\n");
+  for(i=0; i<NCSIZE-1; i++){
+    if( mem.nAlloc[i] ){
+      fprintf(out, "   %5d: %10d %10d %10d\n", 
+            i*8, mem.nAlloc[i], mem.nCurrent[i], mem.mxCurrent[i]);
+    }
+  }
+  if( mem.nAlloc[NCSIZE-1] ){
+    fprintf(out, "   %5d: %10d %10d %10d\n",
+             NCSIZE*8-8, mem.nAlloc[NCSIZE-1],
+             mem.nCurrent[NCSIZE-1], mem.mxCurrent[NCSIZE-1]);
+  }
+  fclose(out);
+}
+
+/*
+** Return the number of times sqlite3MemMalloc() has been called.
+*/
+int sqlite3MemdebugMallocCount(){
+  int i;
+  int nTotal = 0;
+  for(i=0; i<NCSIZE; i++){
+    nTotal += mem.nAlloc[i];
+  }
+  return nTotal;
+}
+
+
+#endif /* SQLITE_MEMDEBUG */
diff --git a/third_party/sqlite/src/mem3.c b/third_party/sqlite/src/mem3.c
new file mode 100755
index 0000000..46a5898
--- /dev/null
+++ b/third_party/sqlite/src/mem3.c
@@ -0,0 +1,682 @@
+/*
+** 2007 October 14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the C functions that implement a memory
+** allocation subsystem for use by SQLite. 
+**
+** This version of the memory allocation subsystem omits all
+** use of malloc(). The SQLite user supplies a block of memory
+** before calling sqlite3_initialize() from which allocations
+** are made and returned by the xMalloc() and xRealloc() 
+** implementations. Once sqlite3_initialize() has been called,
+** the amount of memory available to SQLite is fixed and cannot
+** be changed.
+**
+** This version of the memory allocation subsystem is included
+** in the build only if SQLITE_ENABLE_MEMSYS3 is defined.
+**
+** $Id: mem3.c,v 1.20 2008/07/18 18:56:17 drh Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** This version of the memory allocator is only built into the library
+** SQLITE_ENABLE_MEMSYS3 is defined. Defining this symbol does not
+** mean that the library will use a memory-pool by default, just that
+** it is available. The mempool allocator is activated by calling
+** sqlite3_config().
+*/
+#ifdef SQLITE_ENABLE_MEMSYS3
+
+/*
+** Maximum size (in Mem3Blocks) of a "small" chunk.
+*/
+#define MX_SMALL 10
+
+
+/*
+** Number of freelist hash slots
+*/
+#define N_HASH  61
+
+/*
+** A memory allocation (also called a "chunk") consists of two or 
+** more blocks where each block is 8 bytes.  The first 8 bytes are 
+** a header that is not returned to the user.
+**
+** A chunk is two or more blocks that is either checked out or
+** free.  The first block has format u.hdr.  u.hdr.size4x is 4 times the
+** size of the allocation in blocks if the allocation is free.
+** The u.hdr.size4x&1 bit is true if the chunk is checked out and
+** false if the chunk is on the freelist.  The u.hdr.size4x&2 bit
+** is true if the previous chunk is checked out and false if the
+** previous chunk is free.  The u.hdr.prevSize field is the size of
+** the previous chunk in blocks if the previous chunk is on the
+** freelist. If the previous chunk is checked out, then
+** u.hdr.prevSize can be part of the data for that chunk and should
+** not be read or written.
+**
+** We often identify a chunk by its index in mem3.aPool[].  When
+** this is done, the chunk index refers to the second block of
+** the chunk.  In this way, the first chunk has an index of 1.
+** A chunk index of 0 means "no such chunk" and is the equivalent
+** of a NULL pointer.
+**
+** The second block of free chunks is of the form u.list.  The
+** two fields form a double-linked list of chunks of related sizes.
+** Pointers to the head of the list are stored in mem3.aiSmall[] 
+** for smaller chunks and mem3.aiHash[] for larger chunks.
+**
+** The second block of a chunk is user data if the chunk is checked 
+** out.  If a chunk is checked out, the user data may extend into
+** the u.hdr.prevSize value of the following chunk.
+*/
+typedef struct Mem3Block Mem3Block;
+struct Mem3Block {
+  union {
+    struct {
+      u32 prevSize;   /* Size of previous chunk in Mem3Block elements */
+      u32 size4x;     /* 4x the size of current chunk in Mem3Block elements */
+    } hdr;
+    struct {
+      u32 next;       /* Index in mem3.aPool[] of next free chunk */
+      u32 prev;       /* Index in mem3.aPool[] of previous free chunk */
+    } list;
+  } u;
+};
+
+/*
+** All of the static variables used by this module are collected
+** into a single structure named "mem3".  This is to keep the
+** static variables organized and to reduce namespace pollution
+** when this module is combined with other in the amalgamation.
+*/
+static struct {
+  /*
+  ** True if we are evaluating an out-of-memory callback.
+  */
+  int alarmBusy;
+  
+  /*
+  ** Mutex to control access to the memory allocation subsystem.
+  */
+  sqlite3_mutex *mutex;
+  
+  /*
+  ** The minimum amount of free space that we have seen.
+  */
+  u32 mnMaster;
+
+  /*
+  ** iMaster is the index of the master chunk.  Most new allocations
+  ** occur off of this chunk.  szMaster is the size (in Mem3Blocks)
+  ** of the current master.  iMaster is 0 if there is not master chunk.
+  ** The master chunk is not in either the aiHash[] or aiSmall[].
+  */
+  u32 iMaster;
+  u32 szMaster;
+
+  /*
+  ** Array of lists of free blocks according to the block size 
+  ** for smaller chunks, or a hash on the block size for larger
+  ** chunks.
+  */
+  u32 aiSmall[MX_SMALL-1];   /* For sizes 2 through MX_SMALL, inclusive */
+  u32 aiHash[N_HASH];        /* For sizes MX_SMALL+1 and larger */
+
+  /*
+  ** Memory available for allocation. nPool is the size of the array
+  ** (in Mem3Blocks) pointed to by aPool less 2.
+  */
+  u32 nPool;
+  Mem3Block *aPool;
+} mem3;
+
+/*
+** Unlink the chunk at mem3.aPool[i] from list it is currently
+** on.  *pRoot is the list that i is a member of.
+*/
+static void memsys3UnlinkFromList(u32 i, u32 *pRoot){
+  u32 next = mem3.aPool[i].u.list.next;
+  u32 prev = mem3.aPool[i].u.list.prev;
+  assert( sqlite3_mutex_held(mem3.mutex) );
+  if( prev==0 ){
+    *pRoot = next;
+  }else{
+    mem3.aPool[prev].u.list.next = next;
+  }
+  if( next ){
+    mem3.aPool[next].u.list.prev = prev;
+  }
+  mem3.aPool[i].u.list.next = 0;
+  mem3.aPool[i].u.list.prev = 0;
+}
+
+/*
+** Unlink the chunk at index i from 
+** whatever list is currently a member of.
+*/
+static void memsys3Unlink(u32 i){
+  u32 size, hash;
+  assert( sqlite3_mutex_held(mem3.mutex) );
+  assert( (mem3.aPool[i-1].u.hdr.size4x & 1)==0 );
+  assert( i>=1 );
+  size = mem3.aPool[i-1].u.hdr.size4x/4;
+  assert( size==mem3.aPool[i+size-1].u.hdr.prevSize );
+  assert( size>=2 );
+  if( size <= MX_SMALL ){
+    memsys3UnlinkFromList(i, &mem3.aiSmall[size-2]);
+  }else{
+    hash = size % N_HASH;
+    memsys3UnlinkFromList(i, &mem3.aiHash[hash]);
+  }
+}
+
+/*
+** Link the chunk at mem3.aPool[i] so that is on the list rooted
+** at *pRoot.
+*/
+static void memsys3LinkIntoList(u32 i, u32 *pRoot){
+  assert( sqlite3_mutex_held(mem3.mutex) );
+  mem3.aPool[i].u.list.next = *pRoot;
+  mem3.aPool[i].u.list.prev = 0;
+  if( *pRoot ){
+    mem3.aPool[*pRoot].u.list.prev = i;
+  }
+  *pRoot = i;
+}
+
+/*
+** Link the chunk at index i into either the appropriate
+** small chunk list, or into the large chunk hash table.
+*/
+static void memsys3Link(u32 i){
+  u32 size, hash;
+  assert( sqlite3_mutex_held(mem3.mutex) );
+  assert( i>=1 );
+  assert( (mem3.aPool[i-1].u.hdr.size4x & 1)==0 );
+  size = mem3.aPool[i-1].u.hdr.size4x/4;
+  assert( size==mem3.aPool[i+size-1].u.hdr.prevSize );
+  assert( size>=2 );
+  if( size <= MX_SMALL ){
+    memsys3LinkIntoList(i, &mem3.aiSmall[size-2]);
+  }else{
+    hash = size % N_HASH;
+    memsys3LinkIntoList(i, &mem3.aiHash[hash]);
+  }
+}
+
+/*
+** If the STATIC_MEM mutex is not already held, obtain it now. The mutex
+** will already be held (obtained by code in malloc.c) if
+** sqlite3Config.bMemStat is true.
+*/
+static void memsys3Enter(void){
+  if( sqlite3Config.bMemstat==0 && mem3.mutex==0 ){
+    mem3.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
+  }
+  sqlite3_mutex_enter(mem3.mutex);
+}
+static void memsys3Leave(void){
+  sqlite3_mutex_leave(mem3.mutex);
+}
+
+/*
+** Called when we are unable to satisfy an allocation of nBytes.
+*/
+static void memsys3OutOfMemory(int nByte){
+  if( !mem3.alarmBusy ){
+    mem3.alarmBusy = 1;
+    assert( sqlite3_mutex_held(mem3.mutex) );
+    sqlite3_mutex_leave(mem3.mutex);
+    sqlite3_release_memory(nByte);
+    sqlite3_mutex_enter(mem3.mutex);
+    mem3.alarmBusy = 0;
+  }
+}
+
+
+/*
+** Chunk i is a free chunk that has been unlinked.  Adjust its 
+** size parameters for check-out and return a pointer to the 
+** user portion of the chunk.
+*/
+static void *memsys3Checkout(u32 i, int nBlock){
+  u32 x;
+  assert( sqlite3_mutex_held(mem3.mutex) );
+  assert( i>=1 );
+  assert( mem3.aPool[i-1].u.hdr.size4x/4==nBlock );
+  assert( mem3.aPool[i+nBlock-1].u.hdr.prevSize==nBlock );
+  x = mem3.aPool[i-1].u.hdr.size4x;
+  mem3.aPool[i-1].u.hdr.size4x = nBlock*4 | 1 | (x&2);
+  mem3.aPool[i+nBlock-1].u.hdr.prevSize = nBlock;
+  mem3.aPool[i+nBlock-1].u.hdr.size4x |= 2;
+  return &mem3.aPool[i];
+}
+
+/*
+** Carve a piece off of the end of the mem3.iMaster free chunk.
+** Return a pointer to the new allocation.  Or, if the master chunk
+** is not large enough, return 0.
+*/
+static void *memsys3FromMaster(int nBlock){
+  assert( sqlite3_mutex_held(mem3.mutex) );
+  assert( mem3.szMaster>=nBlock );
+  if( nBlock>=mem3.szMaster-1 ){
+    /* Use the entire master */
+    void *p = memsys3Checkout(mem3.iMaster, mem3.szMaster);
+    mem3.iMaster = 0;
+    mem3.szMaster = 0;
+    mem3.mnMaster = 0;
+    return p;
+  }else{
+    /* Split the master block.  Return the tail. */
+    u32 newi, x;
+    newi = mem3.iMaster + mem3.szMaster - nBlock;
+    assert( newi > mem3.iMaster+1 );
+    mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = nBlock;
+    mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x |= 2;
+    mem3.aPool[newi-1].u.hdr.size4x = nBlock*4 + 1;
+    mem3.szMaster -= nBlock;
+    mem3.aPool[newi-1].u.hdr.prevSize = mem3.szMaster;
+    x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;
+    mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;
+    if( mem3.szMaster < mem3.mnMaster ){
+      mem3.mnMaster = mem3.szMaster;
+    }
+    return (void*)&mem3.aPool[newi];
+  }
+}
+
+/*
+** *pRoot is the head of a list of free chunks of the same size
+** or same size hash.  In other words, *pRoot is an entry in either
+** mem3.aiSmall[] or mem3.aiHash[].  
+**
+** This routine examines all entries on the given list and tries
+** to coalesce each entries with adjacent free chunks.  
+**
+** If it sees a chunk that is larger than mem3.iMaster, it replaces 
+** the current mem3.iMaster with the new larger chunk.  In order for
+** this mem3.iMaster replacement to work, the master chunk must be
+** linked into the hash tables.  That is not the normal state of
+** affairs, of course.  The calling routine must link the master
+** chunk before invoking this routine, then must unlink the (possibly
+** changed) master chunk once this routine has finished.
+*/
+static void memsys3Merge(u32 *pRoot){
+  u32 iNext, prev, size, i, x;
+
+  assert( sqlite3_mutex_held(mem3.mutex) );
+  for(i=*pRoot; i>0; i=iNext){
+    iNext = mem3.aPool[i].u.list.next;
+    size = mem3.aPool[i-1].u.hdr.size4x;
+    assert( (size&1)==0 );
+    if( (size&2)==0 ){
+      memsys3UnlinkFromList(i, pRoot);
+      assert( i > mem3.aPool[i-1].u.hdr.prevSize );
+      prev = i - mem3.aPool[i-1].u.hdr.prevSize;
+      if( prev==iNext ){
+        iNext = mem3.aPool[prev].u.list.next;
+      }
+      memsys3Unlink(prev);
+      size = i + size/4 - prev;
+      x = mem3.aPool[prev-1].u.hdr.size4x & 2;
+      mem3.aPool[prev-1].u.hdr.size4x = size*4 | x;
+      mem3.aPool[prev+size-1].u.hdr.prevSize = size;
+      memsys3Link(prev);
+      i = prev;
+    }else{
+      size /= 4;
+    }
+    if( size>mem3.szMaster ){
+      mem3.iMaster = i;
+      mem3.szMaster = size;
+    }
+  }
+}
+
+/*
+** Return a block of memory of at least nBytes in size.
+** Return NULL if unable.
+**
+** This function assumes that the necessary mutexes, if any, are
+** already held by the caller. Hence "Unsafe".
+*/
+static void *memsys3MallocUnsafe(int nByte){
+  u32 i;
+  int nBlock;
+  int toFree;
+
+  assert( sqlite3_mutex_held(mem3.mutex) );
+  assert( sizeof(Mem3Block)==8 );
+  if( nByte<=12 ){
+    nBlock = 2;
+  }else{
+    nBlock = (nByte + 11)/8;
+  }
+  assert( nBlock>=2 );
+
+  /* STEP 1:
+  ** Look for an entry of the correct size in either the small
+  ** chunk table or in the large chunk hash table.  This is
+  ** successful most of the time (about 9 times out of 10).
+  */
+  if( nBlock <= MX_SMALL ){
+    i = mem3.aiSmall[nBlock-2];
+    if( i>0 ){
+      memsys3UnlinkFromList(i, &mem3.aiSmall[nBlock-2]);
+      return memsys3Checkout(i, nBlock);
+    }
+  }else{
+    int hash = nBlock % N_HASH;
+    for(i=mem3.aiHash[hash]; i>0; i=mem3.aPool[i].u.list.next){
+      if( mem3.aPool[i-1].u.hdr.size4x/4==nBlock ){
+        memsys3UnlinkFromList(i, &mem3.aiHash[hash]);
+        return memsys3Checkout(i, nBlock);
+      }
+    }
+  }
+
+  /* STEP 2:
+  ** Try to satisfy the allocation by carving a piece off of the end
+  ** of the master chunk.  This step usually works if step 1 fails.
+  */
+  if( mem3.szMaster>=nBlock ){
+    return memsys3FromMaster(nBlock);
+  }
+
+
+  /* STEP 3:  
+  ** Loop through the entire memory pool.  Coalesce adjacent free
+  ** chunks.  Recompute the master chunk as the largest free chunk.
+  ** Then try again to satisfy the allocation by carving a piece off
+  ** of the end of the master chunk.  This step happens very
+  ** rarely (we hope!)
+  */
+  for(toFree=nBlock*16; toFree<(mem3.nPool*16); toFree *= 2){
+    memsys3OutOfMemory(toFree);
+    if( mem3.iMaster ){
+      memsys3Link(mem3.iMaster);
+      mem3.iMaster = 0;
+      mem3.szMaster = 0;
+    }
+    for(i=0; i<N_HASH; i++){
+      memsys3Merge(&mem3.aiHash[i]);
+    }
+    for(i=0; i<MX_SMALL-1; i++){
+      memsys3Merge(&mem3.aiSmall[i]);
+    }
+    if( mem3.szMaster ){
+      memsys3Unlink(mem3.iMaster);
+      if( mem3.szMaster>=nBlock ){
+        return memsys3FromMaster(nBlock);
+      }
+    }
+  }
+
+  /* If none of the above worked, then we fail. */
+  return 0;
+}
+
+/*
+** Free an outstanding memory allocation.
+**
+** This function assumes that the necessary mutexes, if any, are
+** already held by the caller. Hence "Unsafe".
+*/
+void memsys3FreeUnsafe(void *pOld){
+  Mem3Block *p = (Mem3Block*)pOld;
+  int i;
+  u32 size, x;
+  assert( sqlite3_mutex_held(mem3.mutex) );
+  assert( p>mem3.aPool && p<&mem3.aPool[mem3.nPool] );
+  i = p - mem3.aPool;
+  assert( (mem3.aPool[i-1].u.hdr.size4x&1)==1 );
+  size = mem3.aPool[i-1].u.hdr.size4x/4;
+  assert( i+size<=mem3.nPool+1 );
+  mem3.aPool[i-1].u.hdr.size4x &= ~1;
+  mem3.aPool[i+size-1].u.hdr.prevSize = size;
+  mem3.aPool[i+size-1].u.hdr.size4x &= ~2;
+  memsys3Link(i);
+
+  /* Try to expand the master using the newly freed chunk */
+  if( mem3.iMaster ){
+    while( (mem3.aPool[mem3.iMaster-1].u.hdr.size4x&2)==0 ){
+      size = mem3.aPool[mem3.iMaster-1].u.hdr.prevSize;
+      mem3.iMaster -= size;
+      mem3.szMaster += size;
+      memsys3Unlink(mem3.iMaster);
+      x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;
+      mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;
+      mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = mem3.szMaster;
+    }
+    x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;
+    while( (mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x&1)==0 ){
+      memsys3Unlink(mem3.iMaster+mem3.szMaster);
+      mem3.szMaster += mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x/4;
+      mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;
+      mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = mem3.szMaster;
+    }
+  }
+}
+
+/*
+** Return the size of an outstanding allocation, in bytes.  The
+** size returned omits the 8-byte header overhead.  This only
+** works for chunks that are currently checked out.
+*/
+static int memsys3Size(void *p){
+  Mem3Block *pBlock;
+  if( p==0 ) return 0;
+  pBlock = (Mem3Block*)p;
+  assert( (pBlock[-1].u.hdr.size4x&1)!=0 );
+  return (pBlock[-1].u.hdr.size4x&~3)*2 - 4;
+}
+
+/*
+** Round up a request size to the next valid allocation size.
+*/
+static int memsys3Roundup(int n){
+  if( n<=12 ){
+    return 12;
+  }else{
+    return ((n+11)&~7) - 4;
+  }
+}
+
+/*
+** Allocate nBytes of memory.
+*/
+static void *memsys3Malloc(int nBytes){
+  sqlite3_int64 *p;
+  assert( nBytes>0 );          /* malloc.c filters out 0 byte requests */
+  memsys3Enter();
+  p = memsys3MallocUnsafe(nBytes);
+  memsys3Leave();
+  return (void*)p; 
+}
+
+/*
+** Free memory.
+*/
+void memsys3Free(void *pPrior){
+  assert( pPrior );
+  memsys3Enter();
+  memsys3FreeUnsafe(pPrior);
+  memsys3Leave();
+}
+
+/*
+** Change the size of an existing memory allocation
+*/
+void *memsys3Realloc(void *pPrior, int nBytes){
+  int nOld;
+  void *p;
+  if( pPrior==0 ){
+    return sqlite3_malloc(nBytes);
+  }
+  if( nBytes<=0 ){
+    sqlite3_free(pPrior);
+    return 0;
+  }
+  nOld = memsys3Size(pPrior);
+  if( nBytes<=nOld && nBytes>=nOld-128 ){
+    return pPrior;
+  }
+  memsys3Enter();
+  p = memsys3MallocUnsafe(nBytes);
+  if( p ){
+    if( nOld<nBytes ){
+      memcpy(p, pPrior, nOld);
+    }else{
+      memcpy(p, pPrior, nBytes);
+    }
+    memsys3FreeUnsafe(pPrior);
+  }
+  memsys3Leave();
+  return p;
+}
+
+/*
+** Initialize this module.
+*/
+static int memsys3Init(void *NotUsed){
+  if( !sqlite3Config.pHeap ){
+    return SQLITE_ERROR;
+  }
+
+  /* Store a pointer to the memory block in global structure mem3. */
+  assert( sizeof(Mem3Block)==8 );
+  mem3.aPool = (Mem3Block *)sqlite3Config.pHeap;
+  mem3.nPool = (sqlite3Config.nHeap / sizeof(Mem3Block)) - 2;
+
+  /* Initialize the master block. */
+  mem3.szMaster = mem3.nPool;
+  mem3.mnMaster = mem3.szMaster;
+  mem3.iMaster = 1;
+  mem3.aPool[0].u.hdr.size4x = (mem3.szMaster<<2) + 2;
+  mem3.aPool[mem3.nPool].u.hdr.prevSize = mem3.nPool;
+  mem3.aPool[mem3.nPool].u.hdr.size4x = 1;
+
+  return SQLITE_OK;
+}
+
+/*
+** Deinitialize this module.
+*/
+static void memsys3Shutdown(void *NotUsed){
+  return;
+}
+
+
+
+/*
+** Open the file indicated and write a log of all unfreed memory 
+** allocations into that log.
+*/
+#ifdef SQLITE_DEBUG
+void sqlite3Memsys3Dump(const char *zFilename){
+  FILE *out;
+  int i, j;
+  u32 size;
+  if( zFilename==0 || zFilename[0]==0 ){
+    out = stdout;
+  }else{
+    out = fopen(zFilename, "w");
+    if( out==0 ){
+      fprintf(stderr, "** Unable to output memory debug output log: %s **\n",
+                      zFilename);
+      return;
+    }
+  }
+  memsys3Enter();
+  fprintf(out, "CHUNKS:\n");
+  for(i=1; i<=mem3.nPool; i+=size/4){
+    size = mem3.aPool[i-1].u.hdr.size4x;
+    if( size/4<=1 ){
+      fprintf(out, "%p size error\n", &mem3.aPool[i]);
+      assert( 0 );
+      break;
+    }
+    if( (size&1)==0 && mem3.aPool[i+size/4-1].u.hdr.prevSize!=size/4 ){
+      fprintf(out, "%p tail size does not match\n", &mem3.aPool[i]);
+      assert( 0 );
+      break;
+    }
+    if( ((mem3.aPool[i+size/4-1].u.hdr.size4x&2)>>1)!=(size&1) ){
+      fprintf(out, "%p tail checkout bit is incorrect\n", &mem3.aPool[i]);
+      assert( 0 );
+      break;
+    }
+    if( size&1 ){
+      fprintf(out, "%p %6d bytes checked out\n", &mem3.aPool[i], (size/4)*8-8);
+    }else{
+      fprintf(out, "%p %6d bytes free%s\n", &mem3.aPool[i], (size/4)*8-8,
+                  i==mem3.iMaster ? " **master**" : "");
+    }
+  }
+  for(i=0; i<MX_SMALL-1; i++){
+    if( mem3.aiSmall[i]==0 ) continue;
+    fprintf(out, "small(%2d):", i);
+    for(j = mem3.aiSmall[i]; j>0; j=mem3.aPool[j].u.list.next){
+      fprintf(out, " %p(%d)", &mem3.aPool[j],
+              (mem3.aPool[j-1].u.hdr.size4x/4)*8-8);
+    }
+    fprintf(out, "\n"); 
+  }
+  for(i=0; i<N_HASH; i++){
+    if( mem3.aiHash[i]==0 ) continue;
+    fprintf(out, "hash(%2d):", i);
+    for(j = mem3.aiHash[i]; j>0; j=mem3.aPool[j].u.list.next){
+      fprintf(out, " %p(%d)", &mem3.aPool[j],
+              (mem3.aPool[j-1].u.hdr.size4x/4)*8-8);
+    }
+    fprintf(out, "\n"); 
+  }
+  fprintf(out, "master=%d\n", mem3.iMaster);
+  fprintf(out, "nowUsed=%d\n", mem3.nPool*8 - mem3.szMaster*8);
+  fprintf(out, "mxUsed=%d\n", mem3.nPool*8 - mem3.mnMaster*8);
+  sqlite3_mutex_leave(mem3.mutex);
+  if( out==stdout ){
+    fflush(stdout);
+  }else{
+    fclose(out);
+  }
+}
+#endif
+
+/*
+** This routine is the only routine in this file with external 
+** linkage.
+**
+** Populate the low-level memory allocation function pointers in
+** sqlite3Config.m with pointers to the routines in this file. The
+** arguments specify the block of memory to manage.
+**
+** This routine is only called by sqlite3_config(), and therefore
+** is not required to be threadsafe (it is not).
+*/
+const sqlite3_mem_methods *sqlite3MemGetMemsys3(void){
+  static const sqlite3_mem_methods mempoolMethods = {
+     memsys3Malloc,
+     memsys3Free,
+     memsys3Realloc,
+     memsys3Size,
+     memsys3Roundup,
+     memsys3Init,
+     memsys3Shutdown,
+     0
+  };
+  return &mempoolMethods;
+}
+
+#endif /* SQLITE_ENABLE_MEMSYS3 */
diff --git a/third_party/sqlite/src/mem4.c b/third_party/sqlite/src/mem4.c
new file mode 100755
index 0000000..5a78098
--- /dev/null
+++ b/third_party/sqlite/src/mem4.c
@@ -0,0 +1,393 @@
+/*
+** 2007 August 14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the C functions that implement a memory
+** allocation subsystem for use by SQLite.  
+**
+** $Id: mem4.c,v 1.3 2008/06/18 17:09:10 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** This version of the memory allocator attempts to obtain memory
+** from mmap() if the size of the allocation is close to the size
+** of a virtual memory page.  If the size of the allocation is different
+** from the virtual memory page size, then ordinary malloc() is used.
+** Ordinary malloc is also used if space allocated to mmap() is
+** exhausted.
+**
+** Enable this memory allocation by compiling with -DSQLITE_MMAP_HEAP_SIZE=nnn
+** where nnn is the maximum number of bytes of mmap-ed memory you want 
+** to support.   This module may choose to use less memory than requested.
+**
+*/
+#ifdef SQLITE_MMAP_HEAP_SIZE
+
+/*
+** This is a test version of the memory allocator that attempts to
+** use mmap() and madvise() for allocations and frees of approximately
+** the virtual memory page size.
+*/
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <errno.h>
+#include <unistd.h>
+
+
+/*
+** All of the static variables used by this module are collected
+** into a single structure named "mem".  This is to keep the
+** static variables organized and to reduce namespace pollution
+** when this module is combined with other in the amalgamation.
+*/
+static struct {
+  /*
+  ** The alarm callback and its arguments.  The mem.mutex lock will
+  ** be held while the callback is running.  Recursive calls into
+  ** the memory subsystem are allowed, but no new callbacks will be
+  ** issued.  The alarmBusy variable is set to prevent recursive
+  ** callbacks.
+  */
+  sqlite3_int64 alarmThreshold;
+  void (*alarmCallback)(void*, sqlite3_int64,int);
+  void *alarmArg;
+  int alarmBusy;
+  
+  /*
+  ** Mutex to control access to the memory allocation subsystem.
+  */
+  sqlite3_mutex *mutex;
+  
+  /*
+  ** Current allocation and high-water mark.
+  */
+  sqlite3_int64 nowUsed;
+  sqlite3_int64 mxUsed;
+
+  /*
+  ** Current allocation and high-water marks for mmap allocated memory.
+  */
+  sqlite3_int64 nowUsedMMap;
+  sqlite3_int64 mxUsedMMap;
+
+  /*
+  ** Size of a single mmap page.  Obtained from sysconf().
+  */
+  int szPage;
+  int mnPage;
+
+  /*
+  ** The number of available mmap pages.
+  */
+  int nPage;
+
+  /*
+  ** Index of the first free page.  0 means no pages have been freed.
+  */
+  int firstFree;
+
+  /* First unused page on the top of the heap.
+  */
+  int firstUnused;
+
+  /*
+  ** Bulk memory obtained from from mmap().
+  */
+  char *mmapHeap;   /* first byte of the heap */ 
+
+} mem;
+
+
+/*
+** Enter the mutex mem.mutex. Allocate it if it is not already allocated.
+** The mmap() region is initialized the first time this routine is called.
+*/
+static void memsys4Enter(void){
+  if( mem.mutex==0 ){
+    mem.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
+  }
+  sqlite3_mutex_enter(mem.mutex);
+}
+
+/*
+** Attempt to free memory to the mmap heap.  This only works if
+** the pointer p is within the range of memory addresses that
+** comprise the mmap heap.  Return 1 if the memory was freed
+** successfully.  Return 0 if the pointer is out of range.
+*/
+static int mmapFree(void *p){
+  char *z;
+  int idx, *a;
+  if( mem.mmapHeap==MAP_FAILED || mem.nPage==0 ){
+    return 0;
+  }
+  z = (char*)p;
+  idx = (z - mem.mmapHeap)/mem.szPage;
+  if( idx<1 || idx>=mem.nPage ){
+    return 0;
+  }
+  a = (int*)mem.mmapHeap;
+  a[idx] = a[mem.firstFree];
+  mem.firstFree = idx;
+  mem.nowUsedMMap -= mem.szPage;
+  madvise(p, mem.szPage, MADV_DONTNEED);
+  return 1;
+}
+
+/*
+** Attempt to allocate nBytes from the mmap heap.  Return a pointer
+** to the allocated page.  Or, return NULL if the allocation fails.
+** 
+** The allocation will fail if nBytes is not the right size.
+** Or, the allocation will fail if the mmap heap has been exhausted.
+*/
+static void *mmapAlloc(int nBytes){
+  int idx = 0;
+  if( nBytes>mem.szPage || nBytes<mem.mnPage ){
+    return 0;
+  }
+  if( mem.nPage==0 ){
+    mem.szPage = sysconf(_SC_PAGE_SIZE);
+    mem.mnPage = mem.szPage - mem.szPage/10;
+    mem.nPage = SQLITE_MMAP_HEAP_SIZE/mem.szPage;
+    if( mem.nPage * sizeof(int) > mem.szPage ){
+      mem.nPage = mem.szPage/sizeof(int);
+    }
+    mem.mmapHeap =  mmap(0, mem.szPage*mem.nPage, PROT_WRITE|PROT_READ,
+                         MAP_ANONYMOUS|MAP_SHARED, -1, 0);
+    if( mem.mmapHeap==MAP_FAILED ){
+      mem.firstUnused = errno;
+    }else{
+      mem.firstUnused = 1;
+      mem.nowUsedMMap = mem.szPage;
+    }
+  }
+  if( mem.mmapHeap==MAP_FAILED ){
+    return 0;
+  }
+  if( mem.firstFree ){
+    int idx = mem.firstFree;
+    int *a = (int*)mem.mmapHeap;
+    mem.firstFree = a[idx];
+  }else if( mem.firstUnused<mem.nPage ){
+    idx = mem.firstUnused++;
+  }
+  if( idx ){
+    mem.nowUsedMMap += mem.szPage;
+    if( mem.nowUsedMMap>mem.mxUsedMMap ){
+      mem.mxUsedMMap = mem.nowUsedMMap;
+    }
+    return (void*)&mem.mmapHeap[idx*mem.szPage];
+  }else{
+    return 0;
+  }
+}
+
+/*
+** Release the mmap-ed memory region if it is currently allocated and
+** is not in use.
+*/
+static void mmapUnmap(void){
+  if( mem.mmapHeap==MAP_FAILED ) return;
+  if( mem.nPage==0 ) return;
+  if( mem.nowUsedMMap>mem.szPage ) return;
+  munmap(mem.mmapHeap, mem.nPage*mem.szPage);
+  mem.nowUsedMMap = 0;
+  mem.nPage = 0;
+}
+    
+
+/*
+** Return the amount of memory currently checked out.
+*/
+sqlite3_int64 sqlite3_memory_used(void){
+  sqlite3_int64 n;
+  memsys4Enter();
+  n = mem.nowUsed + mem.nowUsedMMap;
+  sqlite3_mutex_leave(mem.mutex);  
+  return n;
+}
+
+/*
+** Return the maximum amount of memory that has ever been
+** checked out since either the beginning of this process
+** or since the most recent reset.
+*/
+sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
+  sqlite3_int64 n;
+  memsys4Enter();
+  n = mem.mxUsed + mem.mxUsedMMap;
+  if( resetFlag ){
+    mem.mxUsed = mem.nowUsed;
+    mem.mxUsedMMap = mem.nowUsedMMap;
+  }
+  sqlite3_mutex_leave(mem.mutex);  
+  return n;
+}
+
+/*
+** Change the alarm callback
+*/
+int sqlite3_memory_alarm(
+  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
+  void *pArg,
+  sqlite3_int64 iThreshold
+){
+  memsys4Enter();
+  mem.alarmCallback = xCallback;
+  mem.alarmArg = pArg;
+  mem.alarmThreshold = iThreshold;
+  sqlite3_mutex_leave(mem.mutex);
+  return SQLITE_OK;
+}
+
+/*
+** Trigger the alarm 
+*/
+static void sqlite3MemsysAlarm(int nByte){
+  void (*xCallback)(void*,sqlite3_int64,int);
+  sqlite3_int64 nowUsed;
+  void *pArg;
+  if( mem.alarmCallback==0 || mem.alarmBusy  ) return;
+  mem.alarmBusy = 1;
+  xCallback = mem.alarmCallback;
+  nowUsed = mem.nowUsed;
+  pArg = mem.alarmArg;
+  sqlite3_mutex_leave(mem.mutex);
+  xCallback(pArg, nowUsed, nByte);
+  sqlite3_mutex_enter(mem.mutex);
+  mem.alarmBusy = 0;
+}
+
+/*
+** Allocate nBytes of memory
+*/
+static void *memsys4Malloc(int nBytes){
+  sqlite3_int64 *p = 0;
+  if( mem.alarmCallback!=0
+         && mem.nowUsed+mem.nowUsedMMap+nBytes>=mem.alarmThreshold ){
+    sqlite3MemsysAlarm(nBytes);
+  }
+  if( (p = mmapAlloc(nBytes))==0 ){
+    p = malloc(nBytes+8);
+    if( p==0 ){
+      sqlite3MemsysAlarm(nBytes);
+      p = malloc(nBytes+8);
+    }
+    if( p ){
+      p[0] = nBytes;
+      p++;
+      mem.nowUsed += nBytes;
+      if( mem.nowUsed>mem.mxUsed ){
+        mem.mxUsed = mem.nowUsed;
+      }
+    }
+  }
+  return (void*)p; 
+}
+
+/*
+** Return the size of a memory allocation
+*/
+static int memsys4Size(void *pPrior){
+  char *z = (char*)pPrior;
+  int idx = mem.nPage ? (z - mem.mmapHeap)/mem.szPage : 0;
+  int nByte;
+  if( idx>=1 && idx<mem.nPage ){
+    nByte = mem.szPage;
+  }else{
+    sqlite3_int64 *p = pPrior;
+    p--;
+    nByte = (int)*p;
+  }
+  return nByte;
+}
+
+/*
+** Free memory.
+*/
+static void memsys4Free(void *pPrior){
+  sqlite3_int64 *p;
+  int nByte;
+  if( mmapFree(pPrior)==0 ){
+    p = pPrior;
+    p--;
+    nByte = (int)*p;
+    mem.nowUsed -= nByte;
+    free(p);
+    if( mem.nowUsed==0 ){
+      mmapUnmap();
+    }      
+  }
+}
+
+/*
+** Allocate nBytes of memory
+*/
+void *sqlite3_malloc(int nBytes){
+  sqlite3_int64 *p = 0;
+  if( nBytes>0 ){
+    memsys4Enter();
+    p = memsys4Malloc(nBytes);
+    sqlite3_mutex_leave(mem.mutex);
+  }
+  return (void*)p; 
+}
+
+/*
+** Free memory.
+*/
+void sqlite3_free(void *pPrior){
+  if( pPrior==0 ){
+    return;
+  }
+  assert( mem.mutex!=0 );
+  sqlite3_mutex_enter(mem.mutex);
+  memsys4Free(pPrior);
+  sqlite3_mutex_leave(mem.mutex);  
+}
+
+
+
+/*
+** Change the size of an existing memory allocation
+*/
+void *sqlite3_realloc(void *pPrior, int nBytes){
+  int nOld;
+  sqlite3_int64 *p;
+  if( pPrior==0 ){
+    return sqlite3_malloc(nBytes);
+  }
+  if( nBytes<=0 ){
+    sqlite3_free(pPrior);
+    return 0;
+  }
+  nOld = memsys4Size(pPrior);
+  if( nBytes<=nOld && nBytes>=nOld-128 ){
+    return pPrior;
+  }
+  assert( mem.mutex!=0 );
+  sqlite3_mutex_enter(mem.mutex);
+  p = memsys4Malloc(nBytes);
+  if( p ){
+    if( nOld<nBytes ){
+      memcpy(p, pPrior, nOld);
+    }else{
+      memcpy(p, pPrior, nBytes);
+    }
+    memsys4Free(pPrior);
+  }
+  assert( mem.mutex!=0 );
+  sqlite3_mutex_leave(mem.mutex);
+  return (void*)p;
+}
+
+#endif /* SQLITE_MMAP_HEAP_SIZE */
diff --git a/third_party/sqlite/src/mem5.c b/third_party/sqlite/src/mem5.c
new file mode 100755
index 0000000..7ce28a3
--- /dev/null
+++ b/third_party/sqlite/src/mem5.c
@@ -0,0 +1,515 @@
+/*
+** 2007 October 14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the C functions that implement a memory
+** allocation subsystem for use by SQLite. 
+**
+** This version of the memory allocation subsystem omits all
+** use of malloc(). The SQLite user supplies a block of memory
+** before calling sqlite3_initialize() from which allocations
+** are made and returned by the xMalloc() and xRealloc() 
+** implementations. Once sqlite3_initialize() has been called,
+** the amount of memory available to SQLite is fixed and cannot
+** be changed.
+**
+** This version of the memory allocation subsystem is included
+** in the build only if SQLITE_ENABLE_MEMSYS5 is defined.
+**
+** $Id: mem5.c,v 1.11 2008/07/16 12:25:32 drh Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** This version of the memory allocator is used only when 
+** SQLITE_POW2_MEMORY_SIZE is defined.
+*/
+#ifdef SQLITE_ENABLE_MEMSYS5
+
+/*
+** Log2 of the minimum size of an allocation.  For example, if
+** 4 then all allocations will be rounded up to at least 16 bytes.
+** If 5 then all allocations will be rounded up to at least 32 bytes.
+*/
+#ifndef SQLITE_POW2_LOGMIN
+# define SQLITE_POW2_LOGMIN 6
+#endif
+
+/*
+** Log2 of the maximum size of an allocation.
+*/
+#ifndef SQLITE_POW2_LOGMAX
+# define SQLITE_POW2_LOGMAX 20
+#endif
+#define POW2_MAX (((unsigned int)1)<<SQLITE_POW2_LOGMAX)
+
+/*
+** Number of distinct allocation sizes.
+*/
+#define NSIZE (SQLITE_POW2_LOGMAX - SQLITE_POW2_LOGMIN + 1)
+
+/*
+** A minimum allocation is an instance of the following structure.
+** Larger allocations are an array of these structures where the
+** size of the array is a power of 2.
+*/
+typedef struct Mem5Link Mem5Link;
+struct Mem5Link {
+  int next;       /* Index of next free chunk */
+  int prev;       /* Index of previous free chunk */
+};
+
+/*
+** Maximum size of any allocation is ((1<<LOGMAX)*mem5.nAtom). Since
+** mem5.nAtom is always at least 8, this is not really a practical
+** limitation.
+*/
+#define LOGMAX 30
+
+/*
+** Masks used for mem5.aCtrl[] elements.
+*/
+#define CTRL_LOGSIZE  0x1f    /* Log2 Size of this block relative to POW2_MIN */
+#define CTRL_FREE     0x20    /* True if not checked out */
+
+/*
+** All of the static variables used by this module are collected
+** into a single structure named "mem5".  This is to keep the
+** static variables organized and to reduce namespace pollution
+** when this module is combined with other in the amalgamation.
+*/
+static struct {
+  /*
+  ** The alarm callback and its arguments.  The mem5.mutex lock will
+  ** be held while the callback is running.  Recursive calls into
+  ** the memory subsystem are allowed, but no new callbacks will be
+  ** issued.  The alarmBusy variable is set to prevent recursive
+  ** callbacks.
+  */
+  sqlite3_int64 alarmThreshold;
+  void (*alarmCallback)(void*, sqlite3_int64,int);
+  void *alarmArg;
+  int alarmBusy;
+  
+  /*
+  ** Mutex to control access to the memory allocation subsystem.
+  */
+  sqlite3_mutex *mutex;
+
+  /*
+  ** Performance statistics
+  */
+  u64 nAlloc;         /* Total number of calls to malloc */
+  u64 totalAlloc;     /* Total of all malloc calls - includes internal frag */
+  u64 totalExcess;    /* Total internal fragmentation */
+  u32 currentOut;     /* Current checkout, including internal fragmentation */
+  u32 currentCount;   /* Current number of distinct checkouts */
+  u32 maxOut;         /* Maximum instantaneous currentOut */
+  u32 maxCount;       /* Maximum instantaneous currentCount */
+  u32 maxRequest;     /* Largest allocation (exclusive of internal frag) */
+  
+  /*
+  ** Lists of free blocks of various sizes.
+  */
+  int aiFreelist[LOGMAX+1];
+
+  /*
+  ** Space for tracking which blocks are checked out and the size
+  ** of each block.  One byte per block.
+  */
+  u8 *aCtrl;
+
+  /*
+  ** Memory available for allocation
+  */
+  int nAtom;       /* Smallest possible allocation in bytes */
+  int nBlock;      /* Number of nAtom sized blocks in zPool */
+  u8 *zPool;
+} mem5;
+
+#define MEM5LINK(idx) ((Mem5Link *)(&mem5.zPool[(idx)*mem5.nAtom]))
+
+/*
+** Unlink the chunk at mem5.aPool[i] from list it is currently
+** on.  It should be found on mem5.aiFreelist[iLogsize].
+*/
+static void memsys5Unlink(int i, int iLogsize){
+  int next, prev;
+  assert( i>=0 && i<mem5.nBlock );
+  assert( iLogsize>=0 && iLogsize<=LOGMAX );
+  assert( (mem5.aCtrl[i] & CTRL_LOGSIZE)==iLogsize );
+
+  next = MEM5LINK(i)->next;
+  prev = MEM5LINK(i)->prev;
+  if( prev<0 ){
+    mem5.aiFreelist[iLogsize] = next;
+  }else{
+    MEM5LINK(prev)->next = next;
+  }
+  if( next>=0 ){
+    MEM5LINK(next)->prev = prev;
+  }
+}
+
+/*
+** Link the chunk at mem5.aPool[i] so that is on the iLogsize
+** free list.
+*/
+static void memsys5Link(int i, int iLogsize){
+  int x;
+  assert( sqlite3_mutex_held(mem5.mutex) );
+  assert( i>=0 && i<mem5.nBlock );
+  assert( iLogsize>=0 && iLogsize<=LOGMAX );
+  assert( (mem5.aCtrl[i] & CTRL_LOGSIZE)==iLogsize );
+
+  x = MEM5LINK(i)->next = mem5.aiFreelist[iLogsize];
+  MEM5LINK(i)->prev = -1;
+  if( x>=0 ){
+    assert( x<mem5.nBlock );
+    MEM5LINK(x)->prev = i;
+  }
+  mem5.aiFreelist[iLogsize] = i;
+}
+
+/*
+** If the STATIC_MEM mutex is not already held, obtain it now. The mutex
+** will already be held (obtained by code in malloc.c) if
+** sqlite3Config.bMemStat is true.
+*/
+static void memsys5Enter(void){
+  if( sqlite3Config.bMemstat==0 && mem5.mutex==0 ){
+    mem5.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
+  }
+  sqlite3_mutex_enter(mem5.mutex);
+}
+static void memsys5Leave(void){
+  sqlite3_mutex_leave(mem5.mutex);
+}
+
+/*
+** Return the size of an outstanding allocation, in bytes.  The
+** size returned omits the 8-byte header overhead.  This only
+** works for chunks that are currently checked out.
+*/
+static int memsys5Size(void *p){
+  int iSize = 0;
+  if( p ){
+    int i = ((u8 *)p-mem5.zPool)/mem5.nAtom;
+    assert( i>=0 && i<mem5.nBlock );
+    iSize = mem5.nAtom * (1 << (mem5.aCtrl[i]&CTRL_LOGSIZE));
+  }
+  return iSize;
+}
+
+/*
+** Find the first entry on the freelist iLogsize.  Unlink that
+** entry and return its index. 
+*/
+static int memsys5UnlinkFirst(int iLogsize){
+  int i;
+  int iFirst;
+
+  assert( iLogsize>=0 && iLogsize<=LOGMAX );
+  i = iFirst = mem5.aiFreelist[iLogsize];
+  assert( iFirst>=0 );
+  while( i>0 ){
+    if( i<iFirst ) iFirst = i;
+    i = MEM5LINK(i)->next;
+  }
+  memsys5Unlink(iFirst, iLogsize);
+  return iFirst;
+}
+
+/*
+** Return a block of memory of at least nBytes in size.
+** Return NULL if unable.
+*/
+static void *memsys5MallocUnsafe(int nByte){
+  int i;           /* Index of a mem5.aPool[] slot */
+  int iBin;        /* Index into mem5.aiFreelist[] */
+  int iFullSz;     /* Size of allocation rounded up to power of 2 */
+  int iLogsize;    /* Log2 of iFullSz/POW2_MIN */
+
+  /* Keep track of the maximum allocation request.  Even unfulfilled
+  ** requests are counted */
+  if( nByte>mem5.maxRequest ){
+    mem5.maxRequest = nByte;
+  }
+
+  /* Round nByte up to the next valid power of two */
+  if( nByte>POW2_MAX ) return 0;
+  for(iFullSz=mem5.nAtom, iLogsize=0; iFullSz<nByte; iFullSz *= 2, iLogsize++){}
+
+  /* Make sure mem5.aiFreelist[iLogsize] contains at least one free
+  ** block.  If not, then split a block of the next larger power of
+  ** two in order to create a new free block of size iLogsize.
+  */
+  for(iBin=iLogsize; mem5.aiFreelist[iBin]<0 && iBin<=LOGMAX; iBin++){}
+  if( iBin>LOGMAX ) return 0;
+  i = memsys5UnlinkFirst(iBin);
+  while( iBin>iLogsize ){
+    int newSize;
+
+    iBin--;
+    newSize = 1 << iBin;
+    mem5.aCtrl[i+newSize] = CTRL_FREE | iBin;
+    memsys5Link(i+newSize, iBin);
+  }
+  mem5.aCtrl[i] = iLogsize;
+
+  /* Update allocator performance statistics. */
+  mem5.nAlloc++;
+  mem5.totalAlloc += iFullSz;
+  mem5.totalExcess += iFullSz - nByte;
+  mem5.currentCount++;
+  mem5.currentOut += iFullSz;
+  if( mem5.maxCount<mem5.currentCount ) mem5.maxCount = mem5.currentCount;
+  if( mem5.maxOut<mem5.currentOut ) mem5.maxOut = mem5.currentOut;
+
+  /* Return a pointer to the allocated memory. */
+  return (void*)&mem5.zPool[i*mem5.nAtom];
+}
+
+/*
+** Free an outstanding memory allocation.
+*/
+static void memsys5FreeUnsafe(void *pOld){
+  u32 size, iLogsize;
+  int iBlock;             
+
+  /* Set iBlock to the index of the block pointed to by pOld in 
+  ** the array of mem5.nAtom byte blocks pointed to by mem5.zPool.
+  */
+  iBlock = ((u8 *)pOld-mem5.zPool)/mem5.nAtom;
+
+  /* Check that the pointer pOld points to a valid, non-free block. */
+  assert( iBlock>=0 && iBlock<mem5.nBlock );
+  assert( ((u8 *)pOld-mem5.zPool)%mem5.nAtom==0 );
+  assert( (mem5.aCtrl[iBlock] & CTRL_FREE)==0 );
+
+  iLogsize = mem5.aCtrl[iBlock] & CTRL_LOGSIZE;
+  size = 1<<iLogsize;
+  assert( iBlock+size-1<mem5.nBlock );
+
+  mem5.aCtrl[iBlock] |= CTRL_FREE;
+  mem5.aCtrl[iBlock+size-1] |= CTRL_FREE;
+  assert( mem5.currentCount>0 );
+  assert( mem5.currentOut>=0 );
+  mem5.currentCount--;
+  mem5.currentOut -= size*mem5.nAtom;
+  assert( mem5.currentOut>0 || mem5.currentCount==0 );
+  assert( mem5.currentCount>0 || mem5.currentOut==0 );
+
+  mem5.aCtrl[iBlock] = CTRL_FREE | iLogsize;
+  while( iLogsize<LOGMAX ){
+    int iBuddy;
+    if( (iBlock>>iLogsize) & 1 ){
+      iBuddy = iBlock - size;
+    }else{
+      iBuddy = iBlock + size;
+    }
+    assert( iBuddy>=0 );
+    if( (iBuddy+(1<<iLogsize))>mem5.nBlock ) break;
+    if( mem5.aCtrl[iBuddy]!=(CTRL_FREE | iLogsize) ) break;
+    memsys5Unlink(iBuddy, iLogsize);
+    iLogsize++;
+    if( iBuddy<iBlock ){
+      mem5.aCtrl[iBuddy] = CTRL_FREE | iLogsize;
+      mem5.aCtrl[iBlock] = 0;
+      iBlock = iBuddy;
+    }else{
+      mem5.aCtrl[iBlock] = CTRL_FREE | iLogsize;
+      mem5.aCtrl[iBuddy] = 0;
+    }
+    size *= 2;
+  }
+  memsys5Link(iBlock, iLogsize);
+}
+
+/*
+** Allocate nBytes of memory
+*/
+static void *memsys5Malloc(int nBytes){
+  sqlite3_int64 *p = 0;
+  if( nBytes>0 ){
+    memsys5Enter();
+    p = memsys5MallocUnsafe(nBytes);
+    memsys5Leave();
+  }
+  return (void*)p; 
+}
+
+/*
+** Free memory.
+*/
+static void memsys5Free(void *pPrior){
+  if( pPrior==0 ){
+assert(0);
+    return;
+  }
+  memsys5Enter();
+  memsys5FreeUnsafe(pPrior);
+  memsys5Leave();  
+}
+
+/*
+** Change the size of an existing memory allocation
+*/
+static void *memsys5Realloc(void *pPrior, int nBytes){
+  int nOld;
+  void *p;
+  if( pPrior==0 ){
+    return memsys5Malloc(nBytes);
+  }
+  if( nBytes<=0 ){
+    memsys5Free(pPrior);
+    return 0;
+  }
+  nOld = memsys5Size(pPrior);
+  if( nBytes<=nOld ){
+    return pPrior;
+  }
+  memsys5Enter();
+  p = memsys5MallocUnsafe(nBytes);
+  if( p ){
+    memcpy(p, pPrior, nOld);
+    memsys5FreeUnsafe(pPrior);
+  }
+  memsys5Leave();
+  return p;
+}
+
+/*
+** Round up a request size to the next valid allocation size.
+*/
+static int memsys5Roundup(int n){
+  int iFullSz;
+  for(iFullSz=mem5.nAtom; iFullSz<n; iFullSz *= 2);
+  return iFullSz;
+}
+
+static int memsys5Log(int iValue){
+  int iLog;
+  for(iLog=0; (1<<iLog)<iValue; iLog++);
+  return iLog;
+}
+
+/*
+** Initialize this module.
+*/
+static int memsys5Init(void *NotUsed){
+  int ii;
+  int nByte = sqlite3Config.nHeap;
+  u8 *zByte = (u8 *)sqlite3Config.pHeap;
+  int nMinLog;                 /* Log of minimum allocation size in bytes*/
+  int iOffset;
+
+  if( !zByte ){
+    return SQLITE_ERROR;
+  }
+
+  nMinLog = memsys5Log(sqlite3Config.mnReq);
+  mem5.nAtom = (1<<nMinLog);
+  while( sizeof(Mem5Link)>mem5.nAtom ){
+    mem5.nAtom = mem5.nAtom << 1;
+  }
+
+  mem5.nBlock = (nByte / (mem5.nAtom+sizeof(u8)));
+  mem5.zPool = zByte;
+  mem5.aCtrl = (u8 *)&mem5.zPool[mem5.nBlock*mem5.nAtom];
+
+  for(ii=0; ii<=LOGMAX; ii++){
+    mem5.aiFreelist[ii] = -1;
+  }
+
+  iOffset = 0;
+  for(ii=LOGMAX; ii>=0; ii--){
+    int nAlloc = (1<<ii);
+    if( (iOffset+nAlloc)<=mem5.nBlock ){
+      mem5.aCtrl[iOffset] = ii | CTRL_FREE;
+      memsys5Link(iOffset, ii);
+      iOffset += nAlloc;
+    }
+    assert((iOffset+nAlloc)>mem5.nBlock);
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Deinitialize this module.
+*/
+static void memsys5Shutdown(void *NotUsed){
+  return;
+}
+
+/*
+** Open the file indicated and write a log of all unfreed memory 
+** allocations into that log.
+*/
+void sqlite3Memsys5Dump(const char *zFilename){
+#ifdef SQLITE_DEBUG
+  FILE *out;
+  int i, j, n;
+  int nMinLog;
+
+  if( zFilename==0 || zFilename[0]==0 ){
+    out = stdout;
+  }else{
+    out = fopen(zFilename, "w");
+    if( out==0 ){
+      fprintf(stderr, "** Unable to output memory debug output log: %s **\n",
+                      zFilename);
+      return;
+    }
+  }
+  memsys5Enter();
+  nMinLog = memsys5Log(mem5.nAtom);
+  for(i=0; i<=LOGMAX && i+nMinLog<32; i++){
+    for(n=0, j=mem5.aiFreelist[i]; j>=0; j = MEM5LINK(j)->next, n++){}
+    fprintf(out, "freelist items of size %d: %d\n", mem5.nAtom << i, n);
+  }
+  fprintf(out, "mem5.nAlloc       = %llu\n", mem5.nAlloc);
+  fprintf(out, "mem5.totalAlloc   = %llu\n", mem5.totalAlloc);
+  fprintf(out, "mem5.totalExcess  = %llu\n", mem5.totalExcess);
+  fprintf(out, "mem5.currentOut   = %u\n", mem5.currentOut);
+  fprintf(out, "mem5.currentCount = %u\n", mem5.currentCount);
+  fprintf(out, "mem5.maxOut       = %u\n", mem5.maxOut);
+  fprintf(out, "mem5.maxCount     = %u\n", mem5.maxCount);
+  fprintf(out, "mem5.maxRequest   = %u\n", mem5.maxRequest);
+  memsys5Leave();
+  if( out==stdout ){
+    fflush(stdout);
+  }else{
+    fclose(out);
+  }
+#endif
+}
+
+/*
+** This routine is the only routine in this file with external 
+** linkage. It returns a pointer to a static sqlite3_mem_methods
+** struct populated with the memsys5 methods.
+*/
+const sqlite3_mem_methods *sqlite3MemGetMemsys5(void){
+  static const sqlite3_mem_methods memsys5Methods = {
+     memsys5Malloc,
+     memsys5Free,
+     memsys5Realloc,
+     memsys5Size,
+     memsys5Roundup,
+     memsys5Init,
+     memsys5Shutdown,
+     0
+  };
+  return &memsys5Methods;
+}
+
+#endif /* SQLITE_ENABLE_MEMSYS5 */
diff --git a/third_party/sqlite/src/mem6.c b/third_party/sqlite/src/mem6.c
new file mode 100755
index 0000000..95723ad
--- /dev/null
+++ b/third_party/sqlite/src/mem6.c
@@ -0,0 +1,496 @@
+/*
+** 2008 July 24
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains an alternative memory allocation system for SQLite.
+** This system is implemented as a wrapper around the system provided
+** by the operating system - vanilla malloc(), realloc() and free().
+**
+** This system differentiates between requests for "small" allocations 
+** (by default those of 128 bytes or less) and "large" allocations (all
+** others). The 256 byte threshhold is configurable at runtime.
+**
+** All requests for large allocations are passed through to the 
+** default system.
+**
+** Requests for small allocations are met by allocating space within
+** one or more larger "chunks" of memory obtained from the default
+** memory allocation system. Chunks of memory are usually 64KB or 
+** larger. The algorithm used to manage space within each chunk is
+** the same as that used by mem5.c. 
+**
+** This strategy is designed to prevent the default memory allocation
+** system (usually the system malloc) from suffering from heap 
+** fragmentation. On some systems, heap fragmentation can cause a 
+** significant real-time slowdown.
+**
+** $Id: mem6.c,v 1.7 2008/07/28 19:34:53 drh Exp $
+*/
+
+#ifdef SQLITE_ENABLE_MEMSYS6
+
+#include "sqliteInt.h"
+
+/*
+** Maximum size of any "small" allocation is ((1<<LOGMAX)*Mem6Chunk.nAtom).
+** Mem6Chunk.nAtom is always at least 8, so this is not a practical
+** limitation
+*/
+#define LOGMAX 30
+
+/*
+** Default value for the "small" allocation size threshold.
+*/
+#define SMALL_MALLOC_DEFAULT_THRESHOLD 256
+
+/*
+** Minimum size for a memory chunk.
+*/
+#define MIN_CHUNKSIZE (1<<16)
+
+#define LOG2_MINALLOC 4
+
+
+typedef struct Mem6Chunk Mem6Chunk;
+typedef struct Mem6Link Mem6Link;
+
+/*
+** A minimum allocation is an instance of the following structure.
+** Larger allocations are an array of these structures where the
+** size of the array is a power of 2.
+*/
+struct Mem6Link {
+  int next;       /* Index of next free chunk */
+  int prev;       /* Index of previous free chunk */
+};
+
+/*
+** Masks used for mem5.aCtrl[] elements.
+*/
+#define CTRL_LOGSIZE  0x1f    /* Log2 Size of this block relative to POW2_MIN */
+#define CTRL_FREE     0x20    /* True if not checked out */
+
+struct Mem6Chunk {
+  Mem6Chunk *pNext;
+
+  /*
+  ** Lists of free blocks of various sizes.
+  */
+  int aiFreelist[LOGMAX+1];
+
+  int nCheckedOut; /* Number of currently outstanding allocations */
+
+  /*
+  ** Space for tracking which blocks are checked out and the size
+  ** of each block. One byte per block.
+  */
+  u8 *aCtrl;
+
+  /*
+  ** Memory available for allocation
+  */
+  int nAtom;       /* Smallest possible allocation in bytes */
+  int nBlock;      /* Number of nAtom sized blocks in zPool */
+  u8 *zPool;       /* Pointer to memory chunk from which allocations are made */
+};
+
+#define MEM6LINK(idx) ((Mem6Link *)(&pChunk->zPool[(idx)*pChunk->nAtom]))
+
+struct Mem6Global {
+  int nMinAlloc;                  /* Minimum allowed allocation size */
+  int nThreshold;                 /* Allocs larger than this go to malloc() */
+  int nLogThreshold;              /* log2 of (nThreshold/nMinAlloc) */
+  sqlite3_mutex *mutex;
+  Mem6Chunk *pChunk;              /* Singly linked list of all memory chunks */
+} mem6;
+
+/*
+** Unlink the chunk at pChunk->aPool[i] from list it is currently
+** on.  It should be found on pChunk->aiFreelist[iLogsize].
+*/
+static void memsys6Unlink(Mem6Chunk *pChunk, int i, int iLogsize){
+  int next, prev;
+  assert( i>=0 && i<pChunk->nBlock );
+  assert( iLogsize>=0 && iLogsize<=mem6.nLogThreshold );
+  assert( (pChunk->aCtrl[i] & CTRL_LOGSIZE)==iLogsize );
+
+  next = MEM6LINK(i)->next;
+  prev = MEM6LINK(i)->prev;
+  if( prev<0 ){
+    pChunk->aiFreelist[iLogsize] = next;
+  }else{
+    MEM6LINK(prev)->next = next;
+  }
+  if( next>=0 ){
+    MEM6LINK(next)->prev = prev;
+  }
+}
+
+/*
+** Link the chunk at mem5.aPool[i] so that is on the iLogsize
+** free list.
+*/
+static void memsys6Link(Mem6Chunk *pChunk, int i, int iLogsize){
+  int x;
+  assert( i>=0 && i<pChunk->nBlock );
+  assert( iLogsize>=0 && iLogsize<=mem6.nLogThreshold );
+  assert( (pChunk->aCtrl[i] & CTRL_LOGSIZE)==iLogsize );
+
+  x = MEM6LINK(i)->next = pChunk->aiFreelist[iLogsize];
+  MEM6LINK(i)->prev = -1;
+  if( x>=0 ){
+    assert( x<pChunk->nBlock );
+    MEM6LINK(x)->prev = i;
+  }
+  pChunk->aiFreelist[iLogsize] = i;
+}
+
+
+/*
+** Find the first entry on the freelist iLogsize.  Unlink that
+** entry and return its index. 
+*/
+static int memsys6UnlinkFirst(Mem6Chunk *pChunk, int iLogsize){
+  int i;
+  int iFirst;
+
+  assert( iLogsize>=0 && iLogsize<=mem6.nLogThreshold );
+  i = iFirst = pChunk->aiFreelist[iLogsize];
+  assert( iFirst>=0 );
+  memsys6Unlink(pChunk, iFirst, iLogsize);
+  return iFirst;
+}
+
+static int roundupLog2(int n){
+  static const char LogTable256[256] = {
+    0,                                                    /* 1 */
+    1,                                                    /* 2 */
+    2, 2,                                                 /* 3..4 */
+    3, 3, 3, 3,                                           /* 5..8 */
+    4, 4, 4, 4, 4, 4, 4, 4,                               /* 9..16 */
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,       /* 17..32 */
+    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,       /* 33..64 */
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,       /* 65..128 */
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,       /* 129..256 */
+  };
+
+  assert(n<=(1<<16) && n>0);
+  if( n<=256 ) return LogTable256[n-1];
+  return LogTable256[(n>>8) - ((n&0xFF)?0:1)] + 8;
+}
+
+/*
+** Allocate and return a block of (pChunk->nAtom << iLogsize) bytes from chunk
+** pChunk. If the allocation request cannot be satisfied, return 0.
+*/
+static void *chunkMalloc(Mem6Chunk *pChunk, int iLogsize){
+  int i;           /* Index of a mem5.aPool[] slot */
+  int iBin;        /* Index into mem5.aiFreelist[] */
+
+  /* Make sure mem5.aiFreelist[iLogsize] contains at least one free
+  ** block.  If not, then split a block of the next larger power of
+  ** two in order to create a new free block of size iLogsize.
+  */
+  for(iBin=iLogsize; pChunk->aiFreelist[iBin]<0 && iBin<=mem6.nLogThreshold; iBin++){}
+  if( iBin>mem6.nLogThreshold ) return 0;
+  i = memsys6UnlinkFirst(pChunk, iBin);
+  while( iBin>iLogsize ){
+    int newSize;
+    iBin--;
+    newSize = 1 << iBin;
+    pChunk->aCtrl[i+newSize] = CTRL_FREE | iBin;
+    memsys6Link(pChunk, i+newSize, iBin);
+  }
+  pChunk->aCtrl[i] = iLogsize;
+
+  /* Return a pointer to the allocated memory. */
+  pChunk->nCheckedOut++;
+  return (void*)&pChunk->zPool[i*pChunk->nAtom];
+}
+
+/*
+** Free the allocation pointed to by p, which is guaranteed to be non-zero
+** and a part of chunk object pChunk.
+*/
+static void chunkFree(Mem6Chunk *pChunk, void *pOld){
+  u32 size, iLogsize;
+  int iBlock;             
+
+  /* Set iBlock to the index of the block pointed to by pOld in 
+  ** the array of pChunk->nAtom byte blocks pointed to by pChunk->zPool.
+  */
+  iBlock = ((u8 *)pOld-pChunk->zPool)/pChunk->nAtom;
+
+  /* Check that the pointer pOld points to a valid, non-free block. */
+  assert( iBlock>=0 && iBlock<pChunk->nBlock );
+  assert( ((u8 *)pOld-pChunk->zPool)%pChunk->nAtom==0 );
+  assert( (pChunk->aCtrl[iBlock] & CTRL_FREE)==0 );
+
+  iLogsize = pChunk->aCtrl[iBlock] & CTRL_LOGSIZE;
+  size = 1<<iLogsize;
+  assert( iBlock+size-1<pChunk->nBlock );
+
+  pChunk->aCtrl[iBlock] |= CTRL_FREE;
+  pChunk->aCtrl[iBlock+size-1] |= CTRL_FREE;
+
+  pChunk->aCtrl[iBlock] = CTRL_FREE | iLogsize;
+  while( iLogsize<mem6.nLogThreshold ){
+    int iBuddy;
+    if( (iBlock>>iLogsize) & 1 ){
+      iBuddy = iBlock - size;
+    }else{
+      iBuddy = iBlock + size;
+    }
+    assert( iBuddy>=0 );
+    if( (iBuddy+(1<<iLogsize))>pChunk->nBlock ) break;
+    if( pChunk->aCtrl[iBuddy]!=(CTRL_FREE | iLogsize) ) break;
+    memsys6Unlink(pChunk, iBuddy, iLogsize);
+    iLogsize++;
+    if( iBuddy<iBlock ){
+      pChunk->aCtrl[iBuddy] = CTRL_FREE | iLogsize;
+      pChunk->aCtrl[iBlock] = 0;
+      iBlock = iBuddy;
+    }else{
+      pChunk->aCtrl[iBlock] = CTRL_FREE | iLogsize;
+      pChunk->aCtrl[iBuddy] = 0;
+    }
+    size *= 2;
+  }
+  pChunk->nCheckedOut--;
+  memsys6Link(pChunk, iBlock, iLogsize);
+}
+
+/*
+** Return the actual size of the block pointed to by p, which is guaranteed
+** to have been allocated from chunk pChunk.
+*/
+static int chunkSize(Mem6Chunk *pChunk, void *p){
+  int iSize = 0;
+  if( p ){
+    int i = ((u8 *)p-pChunk->zPool)/pChunk->nAtom;
+    assert( i>=0 && i<pChunk->nBlock );
+    iSize = pChunk->nAtom * (1 << (pChunk->aCtrl[i]&CTRL_LOGSIZE));
+  }
+  return iSize;
+}
+
+/*
+** Return true if there are currently no outstanding allocations.
+*/
+static int chunkIsEmpty(Mem6Chunk *pChunk){
+  return (pChunk->nCheckedOut==0);
+}
+
+/*
+** Initialize the buffer zChunk, which is nChunk bytes in size, as
+** an Mem6Chunk object. Return a copy of the zChunk pointer.
+*/
+static Mem6Chunk *chunkInit(u8 *zChunk, int nChunk, int nMinAlloc){
+  int ii;
+  int iOffset;
+  Mem6Chunk *pChunk = (Mem6Chunk *)zChunk;
+
+  assert( nChunk>sizeof(Mem6Chunk) );
+  assert( nMinAlloc>sizeof(Mem6Link) );
+
+  memset(pChunk, 0, sizeof(Mem6Chunk));
+  pChunk->nAtom = nMinAlloc;
+  pChunk->nBlock = ((nChunk-sizeof(Mem6Chunk)) / (pChunk->nAtom+sizeof(u8)));
+
+  pChunk->zPool = (u8 *)&pChunk[1];
+  pChunk->aCtrl = &pChunk->zPool[pChunk->nBlock*pChunk->nAtom];
+
+  for(ii=0; ii<=mem6.nLogThreshold; ii++){
+    pChunk->aiFreelist[ii] = -1;
+  }
+
+  iOffset = 0;
+  for(ii=mem6.nLogThreshold; ii>=0; ii--){
+    int nAlloc = (1<<ii);
+    while( (iOffset+nAlloc)<=pChunk->nBlock ){
+      pChunk->aCtrl[iOffset] = ii | CTRL_FREE;
+      memsys6Link(pChunk, iOffset, ii);
+      iOffset += nAlloc;
+    }
+  }
+
+  return pChunk;
+}
+
+
+static void mem6Enter(void){
+  sqlite3_mutex_enter(mem6.mutex);
+}
+
+static void mem6Leave(void){
+  sqlite3_mutex_leave(mem6.mutex);
+}
+
+/*
+** Based on the number and size of the currently allocated chunks, return
+** the size of the next chunk to allocate, in bytes.
+*/
+static int nextChunkSize(void){
+  int iTotal = MIN_CHUNKSIZE;
+  Mem6Chunk *p;
+  for(p=mem6.pChunk; p; p=p->pNext){
+    iTotal = iTotal*2;
+  }
+  return iTotal;
+}
+
+static void freeChunk(Mem6Chunk *pChunk){
+  Mem6Chunk **pp = &mem6.pChunk;
+  for( pp=&mem6.pChunk; *pp!=pChunk; pp = &(*pp)->pNext );
+  *pp = (*pp)->pNext;
+  free(pChunk);
+}
+
+static void *memsys6Malloc(int nByte){
+  Mem6Chunk *pChunk;
+  void *p = 0;
+  int nTotal = nByte+8;
+  int iOffset = 0;
+
+  if( nTotal>mem6.nThreshold ){
+    p = malloc(nTotal);
+  }else{
+    int iLogsize = 0;
+    if( nTotal>(1<<LOG2_MINALLOC) ){
+      iLogsize = roundupLog2(nTotal) - LOG2_MINALLOC;
+    }
+    mem6Enter();
+    for(pChunk=mem6.pChunk; pChunk; pChunk=pChunk->pNext){
+      p = chunkMalloc(pChunk, iLogsize);
+      if( p ){
+        break;
+      }
+    }
+    if( !p ){
+      int iSize = nextChunkSize();
+      p = malloc(iSize);
+      if( p ){
+        pChunk = chunkInit((u8 *)p, iSize, mem6.nMinAlloc);
+        pChunk->pNext = mem6.pChunk;
+        mem6.pChunk = pChunk;
+        p = chunkMalloc(pChunk, iLogsize);
+        assert(p);
+      }
+    }
+    iOffset = ((u8*)p - (u8*)pChunk);
+    mem6Leave();
+  }
+
+  if( !p ){
+    return 0;
+  }
+  ((u32 *)p)[0] = iOffset;
+  ((u32 *)p)[1] = nByte;
+  return &((u32 *)p)[2];
+}
+
+static int memsys6Size(void *pPrior){
+  if( pPrior==0 ) return 0;
+  return ((u32*)pPrior)[-1];
+}
+
+static void memsys6Free(void *pPrior){
+  int iSlot;
+  void *p = &((u32 *)pPrior)[-2];
+  iSlot = ((u32 *)p)[0];
+  if( iSlot ){
+    Mem6Chunk *pChunk;
+    mem6Enter();
+    pChunk = (Mem6Chunk *)(&((u8 *)p)[-1 * iSlot]);
+    chunkFree(pChunk, p);
+    if( chunkIsEmpty(pChunk) ){
+      freeChunk(pChunk);
+    }
+    mem6Leave();
+  }else{
+    free(p);
+  }
+}
+
+static void *memsys6Realloc(void *p, int nByte){
+  void *p2;
+
+  if( p && nByte<=memsys6Size(p) ){
+    p2 = p;
+  }else{
+    p2 = memsys6Malloc(nByte);
+    if( p && p2 ){
+      memcpy(p2, p, memsys6Size(p));
+      memsys6Free(p);
+    }
+  }
+
+  return p2;
+}
+
+static int memsys6Roundup(int n){
+  if( n>mem6.nThreshold ){
+    return n;
+  }else{
+    return (1<<roundupLog2(n));
+  }
+}
+
+static int memsys6Init(void *pCtx){
+  u8 bMemstat = sqlite3Config.bMemstat;
+  mem6.nMinAlloc = (1 << LOG2_MINALLOC);
+  mem6.pChunk = 0;
+  mem6.nThreshold = sqlite3Config.nSmall;
+  if( mem6.nThreshold<=0 ){
+    mem6.nThreshold = SMALL_MALLOC_DEFAULT_THRESHOLD;
+  }
+  mem6.nLogThreshold = roundupLog2(mem6.nThreshold) - LOG2_MINALLOC;
+  if( !bMemstat ){
+    mem6.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
+  }
+  return SQLITE_OK;
+}
+
+static void memsys6Shutdown(void *pCtx){
+  memset(&mem6, 0, sizeof(mem6));
+}
+
+/*
+** This routine is the only routine in this file with external 
+** linkage. It returns a pointer to a static sqlite3_mem_methods
+** struct populated with the memsys6 methods.
+*/
+const sqlite3_mem_methods *sqlite3MemGetMemsys6(void){
+  static const sqlite3_mem_methods memsys6Methods = {
+     memsys6Malloc,
+     memsys6Free,
+     memsys6Realloc,
+     memsys6Size,
+     memsys6Roundup,
+     memsys6Init,
+     memsys6Shutdown,
+     0
+  };
+  return &memsys6Methods;
+}
+
+#endif
diff --git a/third_party/sqlite/src/mutex.c b/third_party/sqlite/src/mutex.c
new file mode 100755
index 0000000..43e1965eb
--- /dev/null
+++ b/third_party/sqlite/src/mutex.c
@@ -0,0 +1,273 @@
+/*
+** 2007 August 14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the C functions that implement mutexes.
+**
+** The implementation in this file does not provide any mutual
+** exclusion and is thus suitable for use only in applications
+** that use SQLite in a single thread.  But this implementation
+** does do a lot of error checking on mutexes to make sure they
+** are called correctly and at appropriate times.  Hence, this
+** implementation is suitable for testing.
+** debugging purposes
+**
+** $Id: mutex.c,v 1.27 2008/06/19 08:51:24 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+
+#ifndef SQLITE_MUTEX_NOOP
+/*
+** Initialize the mutex system.
+*/
+int sqlite3MutexInit(void){ 
+  int rc = SQLITE_OK;
+  if( sqlite3Config.bCoreMutex ){
+    if( !sqlite3Config.mutex.xMutexAlloc ){
+      /* If the xMutexAlloc method has not been set, then the user did not
+      ** install a mutex implementation via sqlite3_config() prior to 
+      ** sqlite3_initialize() being called. This block copies pointers to
+      ** the default implementation into the sqlite3Config structure.
+      **
+      ** The danger is that although sqlite3_config() is not a threadsafe
+      ** API, sqlite3_initialize() is, and so multiple threads may be
+      ** attempting to run this function simultaneously. To guard write
+      ** access to the sqlite3Config structure, the 'MASTER' static mutex
+      ** is obtained before modifying it.
+      */
+      sqlite3_mutex_methods *p = sqlite3DefaultMutex();
+      sqlite3_mutex *pMaster = 0;
+  
+      rc = p->xMutexInit();
+      if( rc==SQLITE_OK ){
+        pMaster = p->xMutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+        assert(pMaster);
+        p->xMutexEnter(pMaster);
+        assert( sqlite3Config.mutex.xMutexAlloc==0 
+             || sqlite3Config.mutex.xMutexAlloc==p->xMutexAlloc
+        );
+        if( !sqlite3Config.mutex.xMutexAlloc ){
+          sqlite3Config.mutex = *p;
+        }
+        p->xMutexLeave(pMaster);
+      }
+    }else{
+      rc = sqlite3Config.mutex.xMutexInit();
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Shutdown the mutex system. This call frees resources allocated by
+** sqlite3MutexInit().
+*/
+int sqlite3MutexEnd(void){
+  int rc = SQLITE_OK;
+  rc = sqlite3Config.mutex.xMutexEnd();
+  return rc;
+}
+
+/*
+** Retrieve a pointer to a static mutex or allocate a new dynamic one.
+*/
+sqlite3_mutex *sqlite3_mutex_alloc(int id){
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return sqlite3Config.mutex.xMutexAlloc(id);
+}
+
+sqlite3_mutex *sqlite3MutexAlloc(int id){
+  if( !sqlite3Config.bCoreMutex ){
+    return 0;
+  }
+  return sqlite3Config.mutex.xMutexAlloc(id);
+}
+
+/*
+** Free a dynamic mutex.
+*/
+void sqlite3_mutex_free(sqlite3_mutex *p){
+  if( p ){
+    sqlite3Config.mutex.xMutexFree(p);
+  }
+}
+
+/*
+** Obtain the mutex p. If some other thread already has the mutex, block
+** until it can be obtained.
+*/
+void sqlite3_mutex_enter(sqlite3_mutex *p){
+  if( p ){
+    sqlite3Config.mutex.xMutexEnter(p);
+  }
+}
+
+/*
+** Obtain the mutex p. If successful, return SQLITE_OK. Otherwise, if another
+** thread holds the mutex and it cannot be obtained, return SQLITE_BUSY.
+*/
+int sqlite3_mutex_try(sqlite3_mutex *p){
+  int rc = SQLITE_OK;
+  if( p ){
+    return sqlite3Config.mutex.xMutexTry(p);
+  }
+  return rc;
+}
+
+/*
+** The sqlite3_mutex_leave() routine exits a mutex that was previously
+** entered by the same thread.  The behavior is undefined if the mutex 
+** is not currently entered. If a NULL pointer is passed as an argument
+** this function is a no-op.
+*/
+void sqlite3_mutex_leave(sqlite3_mutex *p){
+  if( p ){
+    sqlite3Config.mutex.xMutexLeave(p);
+  }
+}
+
+#ifndef NDEBUG
+/*
+** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
+** intended for use inside assert() statements.
+*/
+int sqlite3_mutex_held(sqlite3_mutex *p){
+  return p==0 || sqlite3Config.mutex.xMutexHeld(p);
+}
+int sqlite3_mutex_notheld(sqlite3_mutex *p){
+  return p==0 || sqlite3Config.mutex.xMutexNotheld(p);
+}
+#endif
+
+#endif
+
+#ifdef SQLITE_MUTEX_NOOP_DEBUG
+/*
+** In this implementation, mutexes do not provide any mutual exclusion.
+** But the error checking is provided.  This implementation is useful
+** for test purposes.
+*/
+
+/*
+** The mutex object
+*/
+struct sqlite3_mutex {
+  int id;     /* The mutex type */
+  int cnt;    /* Number of entries without a matching leave */
+};
+
+/*
+** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
+** intended for use inside assert() statements.
+*/
+static int noopMutexHeld(sqlite3_mutex *p){
+  return p==0 || p->cnt>0;
+}
+static int noopMutexNotheld(sqlite3_mutex *p){
+  return p==0 || p->cnt==0;
+}
+
+/*
+** Initialize and deinitialize the mutex subsystem.
+*/
+static int noopMutexInit(void){ return SQLITE_OK; }
+static int noopMutexEnd(void){ return SQLITE_OK; }
+
+/*
+** The sqlite3_mutex_alloc() routine allocates a new
+** mutex and returns a pointer to it.  If it returns NULL
+** that means that a mutex could not be allocated. 
+*/
+static sqlite3_mutex *noopMutexAlloc(int id){
+  static sqlite3_mutex aStatic[6];
+  sqlite3_mutex *pNew = 0;
+  switch( id ){
+    case SQLITE_MUTEX_FAST:
+    case SQLITE_MUTEX_RECURSIVE: {
+      pNew = sqlite3Malloc(sizeof(*pNew));
+      if( pNew ){
+        pNew->id = id;
+        pNew->cnt = 0;
+      }
+      break;
+    }
+    default: {
+      assert( id-2 >= 0 );
+      assert( id-2 < sizeof(aStatic)/sizeof(aStatic[0]) );
+      pNew = &aStatic[id-2];
+      pNew->id = id;
+      break;
+    }
+  }
+  return pNew;
+}
+
+/*
+** This routine deallocates a previously allocated mutex.
+*/
+static void noopMutexFree(sqlite3_mutex *p){
+  assert( p->cnt==0 );
+  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
+  sqlite3_free(p);
+}
+
+/*
+** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
+** to enter a mutex.  If another thread is already within the mutex,
+** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
+** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
+** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
+** be entered multiple times by the same thread.  In such cases the,
+** mutex must be exited an equal number of times before another thread
+** can enter.  If the same thread tries to enter any other kind of mutex
+** more than once, the behavior is undefined.
+*/
+static void noopMutexEnter(sqlite3_mutex *p){
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || noopMutexNotheld(p) );
+  p->cnt++;
+}
+static int noopMutexTry(sqlite3_mutex *p){
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || noopMutexNotheld(p) );
+  p->cnt++;
+  return SQLITE_OK;
+}
+
+/*
+** The sqlite3_mutex_leave() routine exits a mutex that was
+** previously entered by the same thread.  The behavior
+** is undefined if the mutex is not currently entered or
+** is not currently allocated.  SQLite will never do either.
+*/
+static void noopMutexLeave(sqlite3_mutex *p){
+  assert( noopMutexHeld(p) );
+  p->cnt--;
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || noopMutexNotheld(p) );
+}
+
+sqlite3_mutex_methods *sqlite3DefaultMutex(void){
+  static sqlite3_mutex_methods sMutex = {
+    noopMutexInit,
+    noopMutexEnd,
+    noopMutexAlloc,
+    noopMutexFree,
+    noopMutexEnter,
+    noopMutexTry,
+    noopMutexLeave,
+
+    noopMutexHeld,
+    noopMutexNotheld
+  };
+
+  return &sMutex;
+}
+#endif /* SQLITE_MUTEX_NOOP_DEBUG */
diff --git a/third_party/sqlite/src/mutex.h b/third_party/sqlite/src/mutex.h
new file mode 100755
index 0000000..5f51dda
--- /dev/null
+++ b/third_party/sqlite/src/mutex.h
@@ -0,0 +1,85 @@
+/*
+** 2007 August 28
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains the common header for all mutex implementations.
+** The sqliteInt.h header #includes this file so that it is available
+** to all source files.  We break it out in an effort to keep the code
+** better organized.
+**
+** NOTE:  source files should *not* #include this header file directly.
+** Source files should #include the sqliteInt.h file and let that file
+** include this one indirectly.
+**
+** $Id: mutex.h,v 1.8 2008/06/26 10:41:19 danielk1977 Exp $
+*/
+
+
+#ifdef SQLITE_MUTEX_APPDEF
+/*
+** If SQLITE_MUTEX_APPDEF is defined, then this whole module is
+** omitted and equivalent functionality must be provided by the
+** application that links against the SQLite library.
+*/
+#else
+/*
+** Figure out what version of the code to use.  The choices are
+**
+**   SQLITE_MUTEX_NOOP         For single-threaded applications that
+**                             do not desire error checking.
+**
+**   SQLITE_MUTEX_NOOP_DEBUG   For single-threaded applications with
+**                             error checking to help verify that mutexes
+**                             are being used correctly even though they
+**                             are not needed.  Used when SQLITE_DEBUG is
+**                             defined on single-threaded builds.
+**
+**   SQLITE_MUTEX_PTHREADS     For multi-threaded applications on Unix.
+**
+**   SQLITE_MUTEX_W32          For multi-threaded applications on Win32.
+**
+**   SQLITE_MUTEX_OS2          For multi-threaded applications on OS/2.
+*/
+#define SQLITE_MUTEX_NOOP 1   /* The default */
+#if defined(SQLITE_DEBUG) && !SQLITE_THREADSAFE
+# undef SQLITE_MUTEX_NOOP
+# define SQLITE_MUTEX_NOOP_DEBUG
+#endif
+#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && SQLITE_OS_UNIX
+# undef SQLITE_MUTEX_NOOP
+# define SQLITE_MUTEX_PTHREADS
+#endif
+#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && SQLITE_OS_WIN
+# undef SQLITE_MUTEX_NOOP
+# define SQLITE_MUTEX_W32
+#endif
+#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && SQLITE_OS_OS2
+# undef SQLITE_MUTEX_NOOP
+# define SQLITE_MUTEX_OS2
+#endif
+
+#ifdef SQLITE_MUTEX_NOOP
+/*
+** If this is a no-op implementation, implement everything as macros.
+*/
+#define sqlite3_mutex_alloc(X)    ((sqlite3_mutex*)8)
+#define sqlite3_mutex_free(X)
+#define sqlite3_mutex_enter(X)
+#define sqlite3_mutex_try(X)      SQLITE_OK
+#define sqlite3_mutex_leave(X)
+#define sqlite3_mutex_held(X)     1
+#define sqlite3_mutex_notheld(X)  1
+#define sqlite3MutexAlloc(X)      ((sqlite3_mutex*)8)
+#define sqlite3MutexInit()        SQLITE_OK
+#define sqlite3MutexEnd()
+#endif
+
+#endif /* SQLITE_MUTEX_APPDEF */
diff --git a/third_party/sqlite/src/mutex_os2.c b/third_party/sqlite/src/mutex_os2.c
new file mode 100755
index 0000000..6a44370
--- /dev/null
+++ b/third_party/sqlite/src/mutex_os2.c
@@ -0,0 +1,273 @@
+/*
+** 2007 August 28
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the C functions that implement mutexes for OS/2
+**
+** $Id: mutex_os2.c,v 1.10 2008/06/23 22:13:28 pweilbacher Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** The code in this file is only used if SQLITE_MUTEX_OS2 is defined.
+** See the mutex.h file for details.
+*/
+#ifdef SQLITE_MUTEX_OS2
+
+/********************** OS/2 Mutex Implementation **********************
+**
+** This implementation of mutexes is built using the OS/2 API.
+*/
+
+/*
+** The mutex object
+** Each recursive mutex is an instance of the following structure.
+*/
+struct sqlite3_mutex {
+  HMTX mutex;       /* Mutex controlling the lock */
+  int  id;          /* Mutex type */
+  int  nRef;        /* Number of references */
+  TID  owner;       /* Thread holding this mutex */
+};
+
+#define OS2_MUTEX_INITIALIZER   0,0,0,0
+
+/*
+** Initialize and deinitialize the mutex subsystem.
+*/
+static int os2MutexInit(void){ return SQLITE_OK; }
+static int os2MutexEnd(void){ return SQLITE_OK; }
+
+/*
+** The sqlite3_mutex_alloc() routine allocates a new
+** mutex and returns a pointer to it.  If it returns NULL
+** that means that a mutex could not be allocated. 
+** SQLite will unwind its stack and return an error.  The argument
+** to sqlite3_mutex_alloc() is one of these integer constants:
+**
+** <ul>
+** <li>  SQLITE_MUTEX_FAST               0
+** <li>  SQLITE_MUTEX_RECURSIVE          1
+** <li>  SQLITE_MUTEX_STATIC_MASTER      2
+** <li>  SQLITE_MUTEX_STATIC_MEM         3
+** <li>  SQLITE_MUTEX_STATIC_PRNG        4
+** </ul>
+**
+** The first two constants cause sqlite3_mutex_alloc() to create
+** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
+** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
+** The mutex implementation does not need to make a distinction
+** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
+** not want to.  But SQLite will only request a recursive mutex in
+** cases where it really needs one.  If a faster non-recursive mutex
+** implementation is available on the host platform, the mutex subsystem
+** might return such a mutex in response to SQLITE_MUTEX_FAST.
+**
+** The other allowed parameters to sqlite3_mutex_alloc() each return
+** a pointer to a static preexisting mutex.  Three static mutexes are
+** used by the current version of SQLite.  Future versions of SQLite
+** may add additional static mutexes.  Static mutexes are for internal
+** use by SQLite only.  Applications that use SQLite mutexes should
+** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
+** SQLITE_MUTEX_RECURSIVE.
+**
+** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
+** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
+** returns a different mutex on every call.  But for the static
+** mutex types, the same mutex is returned on every call that has
+** the same type number.
+*/
+static sqlite3_mutex *os2MutexAlloc(int iType){
+  sqlite3_mutex *p = NULL;
+  switch( iType ){
+    case SQLITE_MUTEX_FAST:
+    case SQLITE_MUTEX_RECURSIVE: {
+      p = sqlite3MallocZero( sizeof(*p) );
+      if( p ){
+        p->id = iType;
+        if( DosCreateMutexSem( 0, &p->mutex, 0, FALSE ) != NO_ERROR ){
+          sqlite3_free( p );
+          p = NULL;
+        }
+      }
+      break;
+    }
+    default: {
+      static volatile int isInit = 0;
+      static sqlite3_mutex staticMutexes[] = {
+        { OS2_MUTEX_INITIALIZER, },
+        { OS2_MUTEX_INITIALIZER, },
+        { OS2_MUTEX_INITIALIZER, },
+        { OS2_MUTEX_INITIALIZER, },
+        { OS2_MUTEX_INITIALIZER, },
+        { OS2_MUTEX_INITIALIZER, },
+      };
+      if ( !isInit ){
+        APIRET rc;
+        PTIB ptib;
+        PPIB ppib;
+        HMTX mutex;
+        char name[32];
+        DosGetInfoBlocks( &ptib, &ppib );
+        sqlite3_snprintf( sizeof(name), name, "\\SEM32\\SQLITE%04x",
+                          ppib->pib_ulpid );
+        while( !isInit ){
+          mutex = 0;
+          rc = DosCreateMutexSem( name, &mutex, 0, FALSE);
+          if( rc == NO_ERROR ){
+            int i;
+            if( !isInit ){
+              for( i = 0; i < sizeof(staticMutexes)/sizeof(staticMutexes[0]); i++ ){
+                DosCreateMutexSem( 0, &staticMutexes[i].mutex, 0, FALSE );
+              }
+              isInit = 1;
+            }
+            DosCloseMutexSem( mutex );
+          }else if( rc == ERROR_DUPLICATE_NAME ){
+            DosSleep( 1 );
+          }else{
+            return p;
+          }
+        }
+      }
+      assert( iType-2 >= 0 );
+      assert( iType-2 < sizeof(staticMutexes)/sizeof(staticMutexes[0]) );
+      p = &staticMutexes[iType-2];
+      p->id = iType;
+      break;
+    }
+  }
+  return p;
+}
+
+
+/*
+** This routine deallocates a previously allocated mutex.
+** SQLite is careful to deallocate every mutex that it allocates.
+*/
+static void os2MutexFree(sqlite3_mutex *p){
+  if( p==0 ) return;
+  assert( p->nRef==0 );
+  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
+  DosCloseMutexSem( p->mutex );
+  sqlite3_free( p );
+}
+
+/*
+** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
+** to enter a mutex.  If another thread is already within the mutex,
+** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
+** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
+** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
+** be entered multiple times by the same thread.  In such cases the,
+** mutex must be exited an equal number of times before another thread
+** can enter.  If the same thread tries to enter any other kind of mutex
+** more than once, the behavior is undefined.
+*/
+static void os2MutexEnter(sqlite3_mutex *p){
+  TID tid;
+  PID holder1;
+  ULONG holder2;
+  if( p==0 ) return;
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || os2MutexNotheld(p) );
+  DosRequestMutexSem(p->mutex, SEM_INDEFINITE_WAIT);
+  DosQueryMutexSem(p->mutex, &holder1, &tid, &holder2);
+  p->owner = tid;
+  p->nRef++;
+}
+static int os2MutexTry(sqlite3_mutex *p){
+  int rc;
+  TID tid;
+  PID holder1;
+  ULONG holder2;
+  if( p==0 ) return SQLITE_OK;
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || os2MutexNotheld(p) );
+  if( DosRequestMutexSem(p->mutex, SEM_IMMEDIATE_RETURN) == NO_ERROR) {
+    DosQueryMutexSem(p->mutex, &holder1, &tid, &holder2);
+    p->owner = tid;
+    p->nRef++;
+    rc = SQLITE_OK;
+  } else {
+    rc = SQLITE_BUSY;
+  }
+
+  return rc;
+}
+
+/*
+** The sqlite3_mutex_leave() routine exits a mutex that was
+** previously entered by the same thread.  The behavior
+** is undefined if the mutex is not currently entered or
+** is not currently allocated.  SQLite will never do either.
+*/
+static void os2MutexLeave(sqlite3_mutex *p){
+  TID tid;
+  PID holder1;
+  ULONG holder2;
+  if( p==0 ) return;
+  assert( p->nRef>0 );
+  DosQueryMutexSem(p->mutex, &holder1, &tid, &holder2);
+  assert( p->owner==tid );
+  p->nRef--;
+  assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );
+  DosReleaseMutexSem(p->mutex);
+}
+
+#ifdef SQLITE_DEBUG
+/*
+** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
+** intended for use inside assert() statements.
+*/
+static int os2MutexHeld(sqlite3_mutex *p){
+  TID tid;
+  PID pid;
+  ULONG ulCount;
+  PTIB ptib;
+  if( p!=0 ) {
+    DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
+  } else {
+    DosGetInfoBlocks(&ptib, NULL);
+    tid = ptib->tib_ptib2->tib2_ultid;
+  }
+  return p==0 || (p->nRef!=0 && p->owner==tid);
+}
+static int os2MutexNotheld(sqlite3_mutex *p){
+  TID tid;
+  PID pid;
+  ULONG ulCount;
+  PTIB ptib;
+  if( p!= 0 ) {
+    DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
+  } else {
+    DosGetInfoBlocks(&ptib, NULL);
+    tid = ptib->tib_ptib2->tib2_ultid;
+  }
+  return p==0 || p->nRef==0 || p->owner!=tid;
+}
+#endif
+
+sqlite3_mutex_methods *sqlite3DefaultMutex(void){
+  static sqlite3_mutex_methods sMutex = {
+    os2MutexInit,
+    os2MutexEnd,
+    os2MutexAlloc,
+    os2MutexFree,
+    os2MutexEnter,
+    os2MutexTry,
+    os2MutexLeave,
+#ifdef SQLITE_DEBUG
+    os2MutexHeld,
+    os2MutexNotheld
+#endif
+  };
+
+  return &sMutex;
+}
+#endif /* SQLITE_MUTEX_OS2 */
diff --git a/third_party/sqlite/src/mutex_unix.c b/third_party/sqlite/src/mutex_unix.c
new file mode 100755
index 0000000..31f9a97
--- /dev/null
+++ b/third_party/sqlite/src/mutex_unix.c
@@ -0,0 +1,325 @@
+/*
+** 2007 August 28
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the C functions that implement mutexes for pthreads
+**
+** $Id: mutex_unix.c,v 1.13 2008/07/16 12:33:24 drh Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** The code in this file is only used if we are compiling threadsafe
+** under unix with pthreads.
+**
+** Note that this implementation requires a version of pthreads that
+** supports recursive mutexes.
+*/
+#ifdef SQLITE_MUTEX_PTHREADS
+
+#include <pthread.h>
+
+
+/*
+** Each recursive mutex is an instance of the following structure.
+*/
+struct sqlite3_mutex {
+  pthread_mutex_t mutex;     /* Mutex controlling the lock */
+  int id;                    /* Mutex type */
+  int nRef;                  /* Number of entrances */
+  pthread_t owner;           /* Thread that is within this mutex */
+#ifdef SQLITE_DEBUG
+  int trace;                 /* True to trace changes */
+#endif
+};
+#ifdef SQLITE_DEBUG
+#define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, 0, 0, (pthread_t)0, 0 }
+#else
+#define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, 0, 0, (pthread_t)0 }
+#endif
+
+/*
+** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
+** intended for use only inside assert() statements.  On some platforms,
+** there might be race conditions that can cause these routines to
+** deliver incorrect results.  In particular, if pthread_equal() is
+** not an atomic operation, then these routines might delivery
+** incorrect results.  On most platforms, pthread_equal() is a 
+** comparison of two integers and is therefore atomic.  But we are
+** told that HPUX is not such a platform.  If so, then these routines
+** will not always work correctly on HPUX.
+**
+** On those platforms where pthread_equal() is not atomic, SQLite
+** should be compiled without -DSQLITE_DEBUG and with -DNDEBUG to
+** make sure no assert() statements are evaluated and hence these
+** routines are never called.
+*/
+#ifndef NDEBUG
+static int pthreadMutexHeld(sqlite3_mutex *p){
+  return (p->nRef!=0 && pthread_equal(p->owner, pthread_self()));
+}
+static int pthreadMutexNotheld(sqlite3_mutex *p){
+  return p->nRef==0 || pthread_equal(p->owner, pthread_self())==0;
+}
+#endif
+
+/*
+** Initialize and deinitialize the mutex subsystem.
+*/
+static int pthreadMutexInit(void){ return SQLITE_OK; }
+static int pthreadMutexEnd(void){ return SQLITE_OK; }
+
+/*
+** The sqlite3_mutex_alloc() routine allocates a new
+** mutex and returns a pointer to it.  If it returns NULL
+** that means that a mutex could not be allocated.  SQLite
+** will unwind its stack and return an error.  The argument
+** to sqlite3_mutex_alloc() is one of these integer constants:
+**
+** <ul>
+** <li>  SQLITE_MUTEX_FAST
+** <li>  SQLITE_MUTEX_RECURSIVE
+** <li>  SQLITE_MUTEX_STATIC_MASTER
+** <li>  SQLITE_MUTEX_STATIC_MEM
+** <li>  SQLITE_MUTEX_STATIC_MEM2
+** <li>  SQLITE_MUTEX_STATIC_PRNG
+** <li>  SQLITE_MUTEX_STATIC_LRU
+** </ul>
+**
+** The first two constants cause sqlite3_mutex_alloc() to create
+** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
+** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
+** The mutex implementation does not need to make a distinction
+** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
+** not want to.  But SQLite will only request a recursive mutex in
+** cases where it really needs one.  If a faster non-recursive mutex
+** implementation is available on the host platform, the mutex subsystem
+** might return such a mutex in response to SQLITE_MUTEX_FAST.
+**
+** The other allowed parameters to sqlite3_mutex_alloc() each return
+** a pointer to a static preexisting mutex.  Three static mutexes are
+** used by the current version of SQLite.  Future versions of SQLite
+** may add additional static mutexes.  Static mutexes are for internal
+** use by SQLite only.  Applications that use SQLite mutexes should
+** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
+** SQLITE_MUTEX_RECURSIVE.
+**
+** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
+** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
+** returns a different mutex on every call.  But for the static 
+** mutex types, the same mutex is returned on every call that has
+** the same type number.
+*/
+static sqlite3_mutex *pthreadMutexAlloc(int iType){
+  static sqlite3_mutex staticMutexes[] = {
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER
+  };
+  sqlite3_mutex *p;
+  switch( iType ){
+    case SQLITE_MUTEX_RECURSIVE: {
+      p = sqlite3MallocZero( sizeof(*p) );
+      if( p ){
+#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
+        /* If recursive mutexes are not available, we will have to
+        ** build our own.  See below. */
+        pthread_mutex_init(&p->mutex, 0);
+#else
+        /* Use a recursive mutex if it is available */
+        pthread_mutexattr_t recursiveAttr;
+        pthread_mutexattr_init(&recursiveAttr);
+        pthread_mutexattr_settype(&recursiveAttr, PTHREAD_MUTEX_RECURSIVE);
+        pthread_mutex_init(&p->mutex, &recursiveAttr);
+        pthread_mutexattr_destroy(&recursiveAttr);
+#endif
+        p->id = iType;
+      }
+      break;
+    }
+    case SQLITE_MUTEX_FAST: {
+      p = sqlite3MallocZero( sizeof(*p) );
+      if( p ){
+        p->id = iType;
+        pthread_mutex_init(&p->mutex, 0);
+      }
+      break;
+    }
+    default: {
+      assert( iType-2 >= 0 );
+      assert( iType-2 < sizeof(staticMutexes)/sizeof(staticMutexes[0]) );
+      p = &staticMutexes[iType-2];
+      p->id = iType;
+      break;
+    }
+  }
+  return p;
+}
+
+
+/*
+** This routine deallocates a previously
+** allocated mutex.  SQLite is careful to deallocate every
+** mutex that it allocates.
+*/
+static void pthreadMutexFree(sqlite3_mutex *p){
+  assert( p->nRef==0 );
+  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
+  pthread_mutex_destroy(&p->mutex);
+  sqlite3_free(p);
+}
+
+/*
+** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
+** to enter a mutex.  If another thread is already within the mutex,
+** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
+** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
+** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
+** be entered multiple times by the same thread.  In such cases the,
+** mutex must be exited an equal number of times before another thread
+** can enter.  If the same thread tries to enter any other kind of mutex
+** more than once, the behavior is undefined.
+*/
+static void pthreadMutexEnter(sqlite3_mutex *p){
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || pthreadMutexNotheld(p) );
+
+#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
+  /* If recursive mutexes are not available, then we have to grow
+  ** our own.  This implementation assumes that pthread_equal()
+  ** is atomic - that it cannot be deceived into thinking self
+  ** and p->owner are equal if p->owner changes between two values
+  ** that are not equal to self while the comparison is taking place.
+  ** This implementation also assumes a coherent cache - that 
+  ** separate processes cannot read different values from the same
+  ** address at the same time.  If either of these two conditions
+  ** are not met, then the mutexes will fail and problems will result.
+  */
+  {
+    pthread_t self = pthread_self();
+    if( p->nRef>0 && pthread_equal(p->owner, self) ){
+      p->nRef++;
+    }else{
+      pthread_mutex_lock(&p->mutex);
+      assert( p->nRef==0 );
+      p->owner = self;
+      p->nRef = 1;
+    }
+  }
+#else
+  /* Use the built-in recursive mutexes if they are available.
+  */
+  pthread_mutex_lock(&p->mutex);
+  p->owner = pthread_self();
+  p->nRef++;
+#endif
+
+#ifdef SQLITE_DEBUG
+  if( p->trace ){
+    printf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
+  }
+#endif
+}
+static int pthreadMutexTry(sqlite3_mutex *p){
+  int rc;
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || pthreadMutexNotheld(p) );
+
+#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
+  /* If recursive mutexes are not available, then we have to grow
+  ** our own.  This implementation assumes that pthread_equal()
+  ** is atomic - that it cannot be deceived into thinking self
+  ** and p->owner are equal if p->owner changes between two values
+  ** that are not equal to self while the comparison is taking place.
+  ** This implementation also assumes a coherent cache - that 
+  ** separate processes cannot read different values from the same
+  ** address at the same time.  If either of these two conditions
+  ** are not met, then the mutexes will fail and problems will result.
+  */
+  {
+    pthread_t self = pthread_self();
+    if( p->nRef>0 && pthread_equal(p->owner, self) ){
+      p->nRef++;
+      rc = SQLITE_OK;
+    }else if( pthread_mutex_trylock(&p->mutex)==0 ){
+      assert( p->nRef==0 );
+      p->owner = self;
+      p->nRef = 1;
+      rc = SQLITE_OK;
+    }else{
+      rc = SQLITE_BUSY;
+    }
+  }
+#else
+  /* Use the built-in recursive mutexes if they are available.
+  */
+  if( pthread_mutex_trylock(&p->mutex)==0 ){
+    p->owner = pthread_self();
+    p->nRef++;
+    rc = SQLITE_OK;
+  }else{
+    rc = SQLITE_BUSY;
+  }
+#endif
+
+#ifdef SQLITE_DEBUG
+  if( rc==SQLITE_OK && p->trace ){
+    printf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
+  }
+#endif
+  return rc;
+}
+
+/*
+** The sqlite3_mutex_leave() routine exits a mutex that was
+** previously entered by the same thread.  The behavior
+** is undefined if the mutex is not currently entered or
+** is not currently allocated.  SQLite will never do either.
+*/
+static void pthreadMutexLeave(sqlite3_mutex *p){
+  assert( pthreadMutexHeld(p) );
+  p->nRef--;
+  assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );
+
+#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
+  if( p->nRef==0 ){
+    pthread_mutex_unlock(&p->mutex);
+  }
+#else
+  pthread_mutex_unlock(&p->mutex);
+#endif
+
+#ifdef SQLITE_DEBUG
+  if( p->trace ){
+    printf("leave mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
+  }
+#endif
+}
+
+sqlite3_mutex_methods *sqlite3DefaultMutex(void){
+  static sqlite3_mutex_methods sMutex = {
+    pthreadMutexInit,
+    pthreadMutexEnd,
+    pthreadMutexAlloc,
+    pthreadMutexFree,
+    pthreadMutexEnter,
+    pthreadMutexTry,
+    pthreadMutexLeave,
+#ifdef SQLITE_DEBUG
+    pthreadMutexHeld,
+    pthreadMutexNotheld
+#endif
+  };
+
+  return &sMutex;
+}
+
+#endif /* SQLITE_MUTEX_PTHREAD */
diff --git a/third_party/sqlite/src/mutex_w32.c b/third_party/sqlite/src/mutex_w32.c
new file mode 100755
index 0000000..d72f0a3
--- /dev/null
+++ b/third_party/sqlite/src/mutex_w32.c
@@ -0,0 +1,244 @@
+/*
+** 2007 August 14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the C functions that implement mutexes for win32
+**
+** $Id: mutex_w32.c,v 1.11 2008/06/26 10:41:19 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** The code in this file is only used if we are compiling multithreaded
+** on a win32 system.
+*/
+#ifdef SQLITE_MUTEX_W32
+
+/*
+** Each recursive mutex is an instance of the following structure.
+*/
+struct sqlite3_mutex {
+  CRITICAL_SECTION mutex;    /* Mutex controlling the lock */
+  int id;                    /* Mutex type */
+  int nRef;                  /* Number of enterances */
+  DWORD owner;               /* Thread holding this mutex */
+};
+
+/*
+** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,
+** or WinCE.  Return false (zero) for Win95, Win98, or WinME.
+**
+** Here is an interesting observation:  Win95, Win98, and WinME lack
+** the LockFileEx() API.  But we can still statically link against that
+** API as long as we don't call it win running Win95/98/ME.  A call to
+** this routine is used to determine if the host is Win95/98/ME or
+** WinNT/2K/XP so that we will know whether or not we can safely call
+** the LockFileEx() API.
+*/
+#if SQLITE_OS_WINCE
+# define mutexIsNT()  (1)
+#else
+  static int mutexIsNT(void){
+    static int osType = 0;
+    if( osType==0 ){
+      OSVERSIONINFO sInfo;
+      sInfo.dwOSVersionInfoSize = sizeof(sInfo);
+      GetVersionEx(&sInfo);
+      osType = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
+    }
+    return osType==2;
+  }
+#endif /* SQLITE_OS_WINCE */
+
+
+#ifdef SQLITE_DEBUG
+/*
+** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
+** intended for use only inside assert() statements.
+*/
+static int winMutexHeld(sqlite3_mutex *p){
+  return p->nRef!=0 && p->owner==GetCurrentThreadId();
+}
+static int winMutexNotheld(sqlite3_mutex *p){
+  return p->nRef==0 || p->owner!=GetCurrentThreadId();
+}
+#endif
+
+
+/*
+** Initialize and deinitialize the mutex subsystem.
+*/
+static int winMutexInit(void){ return SQLITE_OK; }
+static int winMutexEnd(void){ return SQLITE_OK; }
+
+/*
+** The sqlite3_mutex_alloc() routine allocates a new
+** mutex and returns a pointer to it.  If it returns NULL
+** that means that a mutex could not be allocated.  SQLite
+** will unwind its stack and return an error.  The argument
+** to sqlite3_mutex_alloc() is one of these integer constants:
+**
+** <ul>
+** <li>  SQLITE_MUTEX_FAST               0
+** <li>  SQLITE_MUTEX_RECURSIVE          1
+** <li>  SQLITE_MUTEX_STATIC_MASTER      2
+** <li>  SQLITE_MUTEX_STATIC_MEM         3
+** <li>  SQLITE_MUTEX_STATIC_PRNG        4
+** </ul>
+**
+** The first two constants cause sqlite3_mutex_alloc() to create
+** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
+** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
+** The mutex implementation does not need to make a distinction
+** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
+** not want to.  But SQLite will only request a recursive mutex in
+** cases where it really needs one.  If a faster non-recursive mutex
+** implementation is available on the host platform, the mutex subsystem
+** might return such a mutex in response to SQLITE_MUTEX_FAST.
+**
+** The other allowed parameters to sqlite3_mutex_alloc() each return
+** a pointer to a static preexisting mutex.  Three static mutexes are
+** used by the current version of SQLite.  Future versions of SQLite
+** may add additional static mutexes.  Static mutexes are for internal
+** use by SQLite only.  Applications that use SQLite mutexes should
+** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
+** SQLITE_MUTEX_RECURSIVE.
+**
+** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
+** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
+** returns a different mutex on every call.  But for the static 
+** mutex types, the same mutex is returned on every call that has
+** the same type number.
+*/
+static sqlite3_mutex *winMutexAlloc(int iType){
+  sqlite3_mutex *p;
+
+  switch( iType ){
+    case SQLITE_MUTEX_FAST:
+    case SQLITE_MUTEX_RECURSIVE: {
+      p = sqlite3MallocZero( sizeof(*p) );
+      if( p ){
+        p->id = iType;
+        InitializeCriticalSection(&p->mutex);
+      }
+      break;
+    }
+    default: {
+      static sqlite3_mutex staticMutexes[6];
+      static int isInit = 0;
+      while( !isInit ){
+        static long lock = 0;
+        if( InterlockedIncrement(&lock)==1 ){
+          int i;
+          for(i=0; i<sizeof(staticMutexes)/sizeof(staticMutexes[0]); i++){
+            InitializeCriticalSection(&staticMutexes[i].mutex);
+          }
+          isInit = 1;
+        }else{
+          Sleep(1);
+        }
+      }
+      assert( iType-2 >= 0 );
+      assert( iType-2 < sizeof(staticMutexes)/sizeof(staticMutexes[0]) );
+      p = &staticMutexes[iType-2];
+      p->id = iType;
+      break;
+    }
+  }
+  return p;
+}
+
+
+/*
+** This routine deallocates a previously
+** allocated mutex.  SQLite is careful to deallocate every
+** mutex that it allocates.
+*/
+static void winMutexFree(sqlite3_mutex *p){
+  assert( p );
+  assert( p->nRef==0 );
+  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
+  DeleteCriticalSection(&p->mutex);
+  sqlite3_free(p);
+}
+
+/*
+** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
+** to enter a mutex.  If another thread is already within the mutex,
+** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
+** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
+** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
+** be entered multiple times by the same thread.  In such cases the,
+** mutex must be exited an equal number of times before another thread
+** can enter.  If the same thread tries to enter any other kind of mutex
+** more than once, the behavior is undefined.
+*/
+static void winMutexEnter(sqlite3_mutex *p){
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld(p) );
+  EnterCriticalSection(&p->mutex);
+  p->owner = GetCurrentThreadId(); 
+  p->nRef++;
+}
+static int winMutexTry(sqlite3_mutex *p){
+  int rc = SQLITE_BUSY;
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld(p) );
+  /*
+  ** The sqlite3_mutex_try() routine is very rarely used, and when it
+  ** is used it is merely an optimization.  So it is OK for it to always
+  ** fail.  
+  **
+  ** The TryEnterCriticalSection() interface is only available on WinNT.
+  ** And some windows compilers complain if you try to use it without
+  ** first doing some #defines that prevent SQLite from building on Win98.
+  ** For that reason, we will omit this optimization for now.  See
+  ** ticket #2685.
+  */
+#if 0
+  if( mutexIsNT() && TryEnterCriticalSection(&p->mutex) ){
+    p->owner = GetCurrentThreadId();
+    p->nRef++;
+    rc = SQLITE_OK;
+  }
+#endif
+  return rc;
+}
+
+/*
+** The sqlite3_mutex_leave() routine exits a mutex that was
+** previously entered by the same thread.  The behavior
+** is undefined if the mutex is not currently entered or
+** is not currently allocated.  SQLite will never do either.
+*/
+static void winMutexLeave(sqlite3_mutex *p){
+  assert( p->nRef>0 );
+  assert( p->owner==GetCurrentThreadId() );
+  p->nRef--;
+  assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );
+  LeaveCriticalSection(&p->mutex);
+}
+
+sqlite3_mutex_methods *sqlite3DefaultMutex(void){
+  static sqlite3_mutex_methods sMutex = {
+    winMutexInit,
+    winMutexEnd,
+    winMutexAlloc,
+    winMutexFree,
+    winMutexEnter,
+    winMutexTry,
+    winMutexLeave,
+#ifdef SQLITE_DEBUG
+    winMutexHeld,
+    winMutexNotheld
+#endif
+  };
+
+  return &sMutex;
+}
+#endif /* SQLITE_MUTEX_W32 */
diff --git a/third_party/sqlite/src/os.c b/third_party/sqlite/src/os.c
new file mode 100755
index 0000000..0f141c37
--- /dev/null
+++ b/third_party/sqlite/src/os.c
@@ -0,0 +1,277 @@
+/*
+** 2005 November 29
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains OS interface code that is common to all
+** architectures.
+**
+** $Id: os.c,v 1.120 2008/07/28 19:34:53 drh Exp $
+*/
+#define _SQLITE_OS_C_ 1
+#include "sqliteInt.h"
+#undef _SQLITE_OS_C_
+
+/*
+** The default SQLite sqlite3_vfs implementations do not allocate
+** memory (actually, os_unix.c allocates a small amount of memory
+** from within OsOpen()), but some third-party implementations may.
+** So we test the effects of a malloc() failing and the sqlite3OsXXX()
+** function returning SQLITE_IOERR_NOMEM using the DO_OS_MALLOC_TEST macro.
+**
+** The following functions are instrumented for malloc() failure 
+** testing:
+**
+**     sqlite3OsOpen()
+**     sqlite3OsRead()
+**     sqlite3OsWrite()
+**     sqlite3OsSync()
+**     sqlite3OsLock()
+**
+*/
+#if defined(SQLITE_TEST) && (SQLITE_OS_WIN==0) && 0
+  #define DO_OS_MALLOC_TEST if (1) {            \
+    void *pTstAlloc = sqlite3Malloc(10);       \
+    if (!pTstAlloc) return SQLITE_IOERR_NOMEM;  \
+    sqlite3_free(pTstAlloc);                    \
+  }
+#else
+  #define DO_OS_MALLOC_TEST
+#endif
+
+/*
+** The following routines are convenience wrappers around methods
+** of the sqlite3_file object.  This is mostly just syntactic sugar. All
+** of this would be completely automatic if SQLite were coded using
+** C++ instead of plain old C.
+*/
+int sqlite3OsClose(sqlite3_file *pId){
+  int rc = SQLITE_OK;
+  if( pId->pMethods ){
+    rc = pId->pMethods->xClose(pId);
+    pId->pMethods = 0;
+  }
+  return rc;
+}
+int sqlite3OsRead(sqlite3_file *id, void *pBuf, int amt, i64 offset){
+  DO_OS_MALLOC_TEST;
+  return id->pMethods->xRead(id, pBuf, amt, offset);
+}
+int sqlite3OsWrite(sqlite3_file *id, const void *pBuf, int amt, i64 offset){
+  DO_OS_MALLOC_TEST;
+  return id->pMethods->xWrite(id, pBuf, amt, offset);
+}
+int sqlite3OsTruncate(sqlite3_file *id, i64 size){
+  return id->pMethods->xTruncate(id, size);
+}
+int sqlite3OsSync(sqlite3_file *id, int flags){
+  DO_OS_MALLOC_TEST;
+  return id->pMethods->xSync(id, flags);
+}
+int sqlite3OsFileSize(sqlite3_file *id, i64 *pSize){
+  DO_OS_MALLOC_TEST;
+  return id->pMethods->xFileSize(id, pSize);
+}
+int sqlite3OsLock(sqlite3_file *id, int lockType){
+  DO_OS_MALLOC_TEST;
+  return id->pMethods->xLock(id, lockType);
+}
+int sqlite3OsUnlock(sqlite3_file *id, int lockType){
+  return id->pMethods->xUnlock(id, lockType);
+}
+int sqlite3OsCheckReservedLock(sqlite3_file *id, int *pResOut){
+  DO_OS_MALLOC_TEST;
+  return id->pMethods->xCheckReservedLock(id, pResOut);
+}
+int sqlite3OsFileControl(sqlite3_file *id, int op, void *pArg){
+  return id->pMethods->xFileControl(id, op, pArg);
+}
+int sqlite3OsSectorSize(sqlite3_file *id){
+  int (*xSectorSize)(sqlite3_file*) = id->pMethods->xSectorSize;
+  return (xSectorSize ? xSectorSize(id) : SQLITE_DEFAULT_SECTOR_SIZE);
+}
+int sqlite3OsDeviceCharacteristics(sqlite3_file *id){
+  return id->pMethods->xDeviceCharacteristics(id);
+}
+
+/*
+** The next group of routines are convenience wrappers around the
+** VFS methods.
+*/
+int sqlite3OsOpen(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  sqlite3_file *pFile, 
+  int flags, 
+  int *pFlagsOut
+){
+  DO_OS_MALLOC_TEST;
+  return pVfs->xOpen(pVfs, zPath, pFile, flags, pFlagsOut);
+}
+int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+  return pVfs->xDelete(pVfs, zPath, dirSync);
+}
+int sqlite3OsAccess(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int flags, 
+  int *pResOut
+){
+  DO_OS_MALLOC_TEST;
+  return pVfs->xAccess(pVfs, zPath, flags, pResOut);
+}
+int sqlite3OsFullPathname(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int nPathOut, 
+  char *zPathOut
+){
+  return pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut);
+}
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+void *sqlite3OsDlOpen(sqlite3_vfs *pVfs, const char *zPath){
+  return pVfs->xDlOpen(pVfs, zPath);
+}
+void sqlite3OsDlError(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
+  pVfs->xDlError(pVfs, nByte, zBufOut);
+}
+void *sqlite3OsDlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol){
+  return pVfs->xDlSym(pVfs, pHandle, zSymbol);
+}
+void sqlite3OsDlClose(sqlite3_vfs *pVfs, void *pHandle){
+  pVfs->xDlClose(pVfs, pHandle);
+}
+#endif /* SQLITE_OMIT_LOAD_EXTENSION */
+int sqlite3OsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
+  return pVfs->xRandomness(pVfs, nByte, zBufOut);
+}
+int sqlite3OsSleep(sqlite3_vfs *pVfs, int nMicro){
+  return pVfs->xSleep(pVfs, nMicro);
+}
+int sqlite3OsCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
+  return pVfs->xCurrentTime(pVfs, pTimeOut);
+}
+
+int sqlite3OsOpenMalloc(
+  sqlite3_vfs *pVfs, 
+  const char *zFile, 
+  sqlite3_file **ppFile, 
+  int flags,
+  int *pOutFlags
+){
+  int rc = SQLITE_NOMEM;
+  sqlite3_file *pFile;
+  pFile = (sqlite3_file *)sqlite3Malloc(pVfs->szOsFile);
+  if( pFile ){
+    rc = sqlite3OsOpen(pVfs, zFile, pFile, flags, pOutFlags);
+    if( rc!=SQLITE_OK ){
+      sqlite3_free(pFile);
+    }else{
+      *ppFile = pFile;
+    }
+  }
+  return rc;
+}
+int sqlite3OsCloseFree(sqlite3_file *pFile){
+  int rc = SQLITE_OK;
+  assert( pFile );
+  rc = sqlite3OsClose(pFile);
+  sqlite3_free(pFile);
+  return rc;
+}
+
+/*
+** The list of all registered VFS implementations.
+*/
+static sqlite3_vfs *vfsList = 0;
+
+/*
+** Locate a VFS by name.  If no name is given, simply return the
+** first VFS on the list.
+*/
+sqlite3_vfs *sqlite3_vfs_find(const char *zVfs){
+  sqlite3_vfs *pVfs = 0;
+#ifndef SQLITE_MUTEX_NOOP
+  sqlite3_mutex *mutex;
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  int rc = sqlite3_initialize();
+  if( rc ) return 0;
+#endif
+#ifndef SQLITE_MUTEX_NOOP
+  mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+#endif
+  sqlite3_mutex_enter(mutex);
+  for(pVfs = vfsList; pVfs; pVfs=pVfs->pNext){
+    if( zVfs==0 ) break;
+    if( strcmp(zVfs, pVfs->zName)==0 ) break;
+  }
+  sqlite3_mutex_leave(mutex);
+  return pVfs;
+}
+
+/*
+** Unlink a VFS from the linked list
+*/
+static void vfsUnlink(sqlite3_vfs *pVfs){
+  assert( sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)) );
+  if( pVfs==0 ){
+    /* No-op */
+  }else if( vfsList==pVfs ){
+    vfsList = pVfs->pNext;
+  }else if( vfsList ){
+    sqlite3_vfs *p = vfsList;
+    while( p->pNext && p->pNext!=pVfs ){
+      p = p->pNext;
+    }
+    if( p->pNext==pVfs ){
+      p->pNext = pVfs->pNext;
+    }
+  }
+}
+
+/*
+** Register a VFS with the system.  It is harmless to register the same
+** VFS multiple times.  The new VFS becomes the default if makeDflt is
+** true.
+*/
+int sqlite3_vfs_register(sqlite3_vfs *pVfs, int makeDflt){
+  sqlite3_mutex *mutex = 0;
+#ifndef SQLITE_OMIT_AUTOINIT
+  int rc = sqlite3_initialize();
+  if( rc ) return rc;
+#endif
+  mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+  sqlite3_mutex_enter(mutex);
+  vfsUnlink(pVfs);
+  if( makeDflt || vfsList==0 ){
+    pVfs->pNext = vfsList;
+    vfsList = pVfs;
+  }else{
+    pVfs->pNext = vfsList->pNext;
+    vfsList->pNext = pVfs;
+  }
+  assert(vfsList);
+  sqlite3_mutex_leave(mutex);
+  return SQLITE_OK;
+}
+
+/*
+** Unregister a VFS so that it is no longer accessible.
+*/
+int sqlite3_vfs_unregister(sqlite3_vfs *pVfs){
+#ifndef SQLITE_MUTEX_NOOP
+  sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+#endif
+  sqlite3_mutex_enter(mutex);
+  vfsUnlink(pVfs);
+  sqlite3_mutex_leave(mutex);
+  return SQLITE_OK;
+}
diff --git a/third_party/sqlite/src/os.h b/third_party/sqlite/src/os.h
new file mode 100755
index 0000000..04ce381
--- /dev/null
+++ b/third_party/sqlite/src/os.h
@@ -0,0 +1,279 @@
+/*
+** 2001 September 16
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This header file (together with is companion C source-code file
+** "os.c") attempt to abstract the underlying operating system so that
+** the SQLite library will work on both POSIX and windows systems.
+**
+** This header file is #include-ed by sqliteInt.h and thus ends up
+** being included by every source file.
+**
+** $Id: os.h,v 1.105 2008/06/26 10:41:19 danielk1977 Exp $
+*/
+#ifndef _SQLITE_OS_H_
+#define _SQLITE_OS_H_
+
+/*
+** Figure out if we are dealing with Unix, Windows, or some other
+** operating system.  After the following block of preprocess macros,
+** all of SQLITE_OS_UNIX, SQLITE_OS_WIN, SQLITE_OS_OS2, and SQLITE_OS_OTHER 
+** will defined to either 1 or 0.  One of the four will be 1.  The other 
+** three will be 0.
+*/
+#ifdef OS_SYMBIAN
+# define SQLITE_OS_SYMBIAN 1
+# define SQLITE_OS_OTHER 1
+#endif
+#if defined(SQLITE_OS_OTHER)
+# if SQLITE_OS_OTHER==1
+#   undef SQLITE_OS_UNIX
+#   define SQLITE_OS_UNIX 0
+#   undef SQLITE_OS_WIN
+#   define SQLITE_OS_WIN 0
+#   undef SQLITE_OS_OS2
+#   define SQLITE_OS_OS2 0
+# else
+#   undef SQLITE_OS_OTHER
+# endif
+#endif
+#if !defined(SQLITE_OS_UNIX) && !defined(SQLITE_OS_OTHER)
+# define SQLITE_OS_OTHER 0
+# ifndef SQLITE_OS_WIN
+#   if defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || defined(__MINGW32__) || defined(__BORLANDC__)
+#     define SQLITE_OS_WIN 1
+#     define SQLITE_OS_UNIX 0
+#     define SQLITE_OS_OS2 0
+#   elif defined(__EMX__) || defined(_OS2) || defined(OS2) || defined(_OS2_) || defined(__OS2__)
+#     define SQLITE_OS_WIN 0
+#     define SQLITE_OS_UNIX 0
+#     define SQLITE_OS_OS2 1
+#   else
+#     define SQLITE_OS_WIN 0
+#     define SQLITE_OS_UNIX 1
+#     define SQLITE_OS_OS2 0
+#  endif
+# else
+#  define SQLITE_OS_UNIX 0
+#  define SQLITE_OS_OS2 0
+# endif
+#else
+# ifndef SQLITE_OS_WIN
+#  define SQLITE_OS_WIN 0
+# endif
+#endif
+
+/*
+** Determine if we are dealing with WindowsCE - which has a much
+** reduced API.
+*/
+#if defined(_WIN32_WCE)
+# define SQLITE_OS_WINCE 1
+#else
+# define SQLITE_OS_WINCE 0
+#endif
+
+
+/*
+** Define the maximum size of a temporary filename
+*/
+#if SQLITE_OS_WIN
+# include <windows.h>
+# define SQLITE_TEMPNAME_SIZE (MAX_PATH+50)
+#elif SQLITE_OS_OS2
+# if (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ >= 3) && defined(OS2_HIGH_MEMORY)
+#  include <os2safe.h> /* has to be included before os2.h for linking to work */
+# endif
+# define INCL_DOSDATETIME
+# define INCL_DOSFILEMGR
+# define INCL_DOSERRORS
+# define INCL_DOSMISC
+# define INCL_DOSPROCESS
+# define INCL_DOSMODULEMGR
+# define INCL_DOSSEMAPHORES
+# include <os2.h>
+# include <uconv.h>
+# define SQLITE_TEMPNAME_SIZE (CCHMAXPATHCOMP)
+#else
+# define SQLITE_TEMPNAME_SIZE 200
+#endif
+
+/* If the SET_FULLSYNC macro is not defined above, then make it
+** a no-op
+*/
+#ifndef SET_FULLSYNC
+# define SET_FULLSYNC(x,y)
+#endif
+
+/*
+** The default size of a disk sector
+*/
+#ifndef SQLITE_DEFAULT_SECTOR_SIZE
+# define SQLITE_DEFAULT_SECTOR_SIZE 512
+#endif
+
+/*
+** Temporary files are named starting with this prefix followed by 16 random
+** alphanumeric characters, and no file extension. They are stored in the
+** OS's standard temporary file directory, and are deleted prior to exit.
+** If sqlite is being embedded in another program, you may wish to change the
+** prefix to reflect your program's name, so that if your program exits
+** prematurely, old temporary files can be easily identified. This can be done
+** using -DSQLITE_TEMP_FILE_PREFIX=myprefix_ on the compiler command line.
+**
+** 2006-10-31:  The default prefix used to be "sqlite_".  But then
+** Mcafee started using SQLite in their anti-virus product and it
+** started putting files with the "sqlite" name in the c:/temp folder.
+** This annoyed many windows users.  Those users would then do a 
+** Google search for "sqlite", find the telephone numbers of the
+** developers and call to wake them up at night and complain.
+** For this reason, the default name prefix is changed to be "sqlite" 
+** spelled backwards.  So the temp files are still identified, but
+** anybody smart enough to figure out the code is also likely smart
+** enough to know that calling the developer will not help get rid
+** of the file.
+*/
+#ifndef SQLITE_TEMP_FILE_PREFIX
+# define SQLITE_TEMP_FILE_PREFIX "etilqs_"
+#endif
+
+/*
+** The following values may be passed as the second argument to
+** sqlite3OsLock(). The various locks exhibit the following semantics:
+**
+** SHARED:    Any number of processes may hold a SHARED lock simultaneously.
+** RESERVED:  A single process may hold a RESERVED lock on a file at
+**            any time. Other processes may hold and obtain new SHARED locks.
+** PENDING:   A single process may hold a PENDING lock on a file at
+**            any one time. Existing SHARED locks may persist, but no new
+**            SHARED locks may be obtained by other processes.
+** EXCLUSIVE: An EXCLUSIVE lock precludes all other locks.
+**
+** PENDING_LOCK may not be passed directly to sqlite3OsLock(). Instead, a
+** process that requests an EXCLUSIVE lock may actually obtain a PENDING
+** lock. This can be upgraded to an EXCLUSIVE lock by a subsequent call to
+** sqlite3OsLock().
+*/
+#define NO_LOCK         0
+#define SHARED_LOCK     1
+#define RESERVED_LOCK   2
+#define PENDING_LOCK    3
+#define EXCLUSIVE_LOCK  4
+
+/*
+** File Locking Notes:  (Mostly about windows but also some info for Unix)
+**
+** We cannot use LockFileEx() or UnlockFileEx() on Win95/98/ME because
+** those functions are not available.  So we use only LockFile() and
+** UnlockFile().
+**
+** LockFile() prevents not just writing but also reading by other processes.
+** A SHARED_LOCK is obtained by locking a single randomly-chosen 
+** byte out of a specific range of bytes. The lock byte is obtained at 
+** random so two separate readers can probably access the file at the 
+** same time, unless they are unlucky and choose the same lock byte.
+** An EXCLUSIVE_LOCK is obtained by locking all bytes in the range.
+** There can only be one writer.  A RESERVED_LOCK is obtained by locking
+** a single byte of the file that is designated as the reserved lock byte.
+** A PENDING_LOCK is obtained by locking a designated byte different from
+** the RESERVED_LOCK byte.
+**
+** On WinNT/2K/XP systems, LockFileEx() and UnlockFileEx() are available,
+** which means we can use reader/writer locks.  When reader/writer locks
+** are used, the lock is placed on the same range of bytes that is used
+** for probabilistic locking in Win95/98/ME.  Hence, the locking scheme
+** will support two or more Win95 readers or two or more WinNT readers.
+** But a single Win95 reader will lock out all WinNT readers and a single
+** WinNT reader will lock out all other Win95 readers.
+**
+** The following #defines specify the range of bytes used for locking.
+** SHARED_SIZE is the number of bytes available in the pool from which
+** a random byte is selected for a shared lock.  The pool of bytes for
+** shared locks begins at SHARED_FIRST. 
+**
+** These #defines are available in sqlite_aux.h so that adaptors for
+** connecting SQLite to other operating systems can use the same byte
+** ranges for locking.  In particular, the same locking strategy and
+** byte ranges are used for Unix.  This leaves open the possiblity of having
+** clients on win95, winNT, and unix all talking to the same shared file
+** and all locking correctly.  To do so would require that samba (or whatever
+** tool is being used for file sharing) implements locks correctly between
+** windows and unix.  I'm guessing that isn't likely to happen, but by
+** using the same locking range we are at least open to the possibility.
+**
+** Locking in windows is manditory.  For this reason, we cannot store
+** actual data in the bytes used for locking.  The pager never allocates
+** the pages involved in locking therefore.  SHARED_SIZE is selected so
+** that all locks will fit on a single page even at the minimum page size.
+** PENDING_BYTE defines the beginning of the locks.  By default PENDING_BYTE
+** is set high so that we don't have to allocate an unused page except
+** for very large databases.  But one should test the page skipping logic 
+** by setting PENDING_BYTE low and running the entire regression suite.
+**
+** Changing the value of PENDING_BYTE results in a subtly incompatible
+** file format.  Depending on how it is changed, you might not notice
+** the incompatibility right away, even running a full regression test.
+** The default location of PENDING_BYTE is the first byte past the
+** 1GB boundary.
+**
+*/
+#ifndef SQLITE_TEST
+#define PENDING_BYTE      0x40000000  /* First byte past the 1GB boundary */
+#else
+extern unsigned int sqlite3_pending_byte;
+#define PENDING_BYTE sqlite3_pending_byte
+#endif
+
+#define RESERVED_BYTE     (PENDING_BYTE+1)
+#define SHARED_FIRST      (PENDING_BYTE+2)
+#define SHARED_SIZE       510
+
+/* 
+** Functions for accessing sqlite3_file methods 
+*/
+int sqlite3OsClose(sqlite3_file*);
+int sqlite3OsRead(sqlite3_file*, void*, int amt, i64 offset);
+int sqlite3OsWrite(sqlite3_file*, const void*, int amt, i64 offset);
+int sqlite3OsTruncate(sqlite3_file*, i64 size);
+int sqlite3OsSync(sqlite3_file*, int);
+int sqlite3OsFileSize(sqlite3_file*, i64 *pSize);
+int sqlite3OsLock(sqlite3_file*, int);
+int sqlite3OsUnlock(sqlite3_file*, int);
+int sqlite3OsCheckReservedLock(sqlite3_file *id, int *pResOut);
+int sqlite3OsFileControl(sqlite3_file*,int,void*);
+int sqlite3OsSectorSize(sqlite3_file *id);
+int sqlite3OsDeviceCharacteristics(sqlite3_file *id);
+
+/* 
+** Functions for accessing sqlite3_vfs methods 
+*/
+int sqlite3OsOpen(sqlite3_vfs *, const char *, sqlite3_file*, int, int *);
+int sqlite3OsDelete(sqlite3_vfs *, const char *, int);
+int sqlite3OsAccess(sqlite3_vfs *, const char *, int, int *pResOut);
+int sqlite3OsFullPathname(sqlite3_vfs *, const char *, int, char *);
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+void *sqlite3OsDlOpen(sqlite3_vfs *, const char *);
+void sqlite3OsDlError(sqlite3_vfs *, int, char *);
+void *sqlite3OsDlSym(sqlite3_vfs *, void *, const char *);
+void sqlite3OsDlClose(sqlite3_vfs *, void *);
+#endif /* SQLITE_OMIT_LOAD_EXTENSION */
+int sqlite3OsRandomness(sqlite3_vfs *, int, char *);
+int sqlite3OsSleep(sqlite3_vfs *, int);
+int sqlite3OsCurrentTime(sqlite3_vfs *, double*);
+
+/*
+** Convenience functions for opening and closing files using 
+** sqlite3_malloc() to obtain space for the file-handle structure.
+*/
+int sqlite3OsOpenMalloc(sqlite3_vfs *, const char *, sqlite3_file **, int,int*);
+int sqlite3OsCloseFree(sqlite3_file *);
+
+#endif /* _SQLITE_OS_H_ */
diff --git a/third_party/sqlite/src/os_common.h b/third_party/sqlite/src/os_common.h
new file mode 100755
index 0000000..5fab7a4
--- /dev/null
+++ b/third_party/sqlite/src/os_common.h
@@ -0,0 +1,137 @@
+/*
+** 2004 May 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains macros and a little bit of code that is common to
+** all of the platform-specific files (os_*.c) and is #included into those
+** files.
+**
+** This file should be #included by the os_*.c files only.  It is not a
+** general purpose header file.
+**
+** $Id: os_common.h,v 1.37 2008/05/29 20:22:37 shane Exp $
+*/
+#ifndef _OS_COMMON_H_
+#define _OS_COMMON_H_
+
+/*
+** At least two bugs have slipped in because we changed the MEMORY_DEBUG
+** macro to SQLITE_DEBUG and some older makefiles have not yet made the
+** switch.  The following code should catch this problem at compile-time.
+*/
+#ifdef MEMORY_DEBUG
+# error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
+#endif
+
+
+/*
+ * When testing, this global variable stores the location of the
+ * pending-byte in the database file.
+ */
+#ifdef SQLITE_TEST
+unsigned int sqlite3_pending_byte = 0x40000000;
+#endif
+
+#ifdef SQLITE_DEBUG
+int sqlite3OSTrace = 0;
+#define OSTRACE1(X)         if( sqlite3OSTrace ) sqlite3DebugPrintf(X)
+#define OSTRACE2(X,Y)       if( sqlite3OSTrace ) sqlite3DebugPrintf(X,Y)
+#define OSTRACE3(X,Y,Z)     if( sqlite3OSTrace ) sqlite3DebugPrintf(X,Y,Z)
+#define OSTRACE4(X,Y,Z,A)   if( sqlite3OSTrace ) sqlite3DebugPrintf(X,Y,Z,A)
+#define OSTRACE5(X,Y,Z,A,B) if( sqlite3OSTrace ) sqlite3DebugPrintf(X,Y,Z,A,B)
+#define OSTRACE6(X,Y,Z,A,B,C) \
+    if(sqlite3OSTrace) sqlite3DebugPrintf(X,Y,Z,A,B,C)
+#define OSTRACE7(X,Y,Z,A,B,C,D) \
+    if(sqlite3OSTrace) sqlite3DebugPrintf(X,Y,Z,A,B,C,D)
+#else
+#define OSTRACE1(X)
+#define OSTRACE2(X,Y)
+#define OSTRACE3(X,Y,Z)
+#define OSTRACE4(X,Y,Z,A)
+#define OSTRACE5(X,Y,Z,A,B)
+#define OSTRACE6(X,Y,Z,A,B,C)
+#define OSTRACE7(X,Y,Z,A,B,C,D)
+#endif
+
+/*
+** Macros for performance tracing.  Normally turned off.  Only works
+** on i486 hardware.
+*/
+#ifdef SQLITE_PERFORMANCE_TRACE
+
+/* 
+** hwtime.h contains inline assembler code for implementing 
+** high-performance timing routines.
+*/
+#include "hwtime.h"
+
+static sqlite_uint64 g_start;
+static sqlite_uint64 g_elapsed;
+#define TIMER_START       g_start=sqlite3Hwtime()
+#define TIMER_END         g_elapsed=sqlite3Hwtime()-g_start
+#define TIMER_ELAPSED     g_elapsed
+#else
+#define TIMER_START
+#define TIMER_END
+#define TIMER_ELAPSED     ((sqlite_uint64)0)
+#endif
+
+/*
+** If we compile with the SQLITE_TEST macro set, then the following block
+** of code will give us the ability to simulate a disk I/O error.  This
+** is used for testing the I/O recovery logic.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
+int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
+int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
+int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
+int sqlite3_io_error_benign = 0;         /* True if errors are benign */
+int sqlite3_diskfull_pending = 0;
+int sqlite3_diskfull = 0;
+#define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
+#define SimulateIOError(CODE)  \
+  if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
+       || sqlite3_io_error_pending-- == 1 )  \
+              { local_ioerr(); CODE; }
+static void local_ioerr(){
+  IOTRACE(("IOERR\n"));
+  sqlite3_io_error_hit++;
+  if( !sqlite3_io_error_benign ) sqlite3_io_error_hardhit++;
+}
+#define SimulateDiskfullError(CODE) \
+   if( sqlite3_diskfull_pending ){ \
+     if( sqlite3_diskfull_pending == 1 ){ \
+       local_ioerr(); \
+       sqlite3_diskfull = 1; \
+       sqlite3_io_error_hit = 1; \
+       CODE; \
+     }else{ \
+       sqlite3_diskfull_pending--; \
+     } \
+   }
+#else
+#define SimulateIOErrorBenign(X)
+#define SimulateIOError(A)
+#define SimulateDiskfullError(A)
+#endif
+
+/*
+** When testing, keep a count of the number of open files.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_open_file_count = 0;
+#define OpenCounter(X)  sqlite3_open_file_count+=(X)
+#else
+#define OpenCounter(X)
+#endif
+
+#endif /* !defined(_OS_COMMON_H_) */
diff --git a/third_party/sqlite/src/os_os2.c b/third_party/sqlite/src/os_os2.c
new file mode 100755
index 0000000..f1af91d
--- /dev/null
+++ b/third_party/sqlite/src/os_os2.c
@@ -0,0 +1,1119 @@
+/*
+** 2006 Feb 14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code that is specific to OS/2.
+**
+** $Id: os_os2.c,v 1.55 2008/07/29 18:49:29 pweilbacher Exp $
+*/
+
+#include "sqliteInt.h"
+
+#if SQLITE_OS_OS2
+
+/*
+** A Note About Memory Allocation:
+**
+** This driver uses malloc()/free() directly rather than going through
+** the SQLite-wrappers sqlite3_malloc()/sqlite3_free().  Those wrappers
+** are designed for use on embedded systems where memory is scarce and
+** malloc failures happen frequently.  OS/2 does not typically run on
+** embedded systems, and when it does the developers normally have bigger
+** problems to worry about than running out of memory.  So there is not
+** a compelling need to use the wrappers.
+**
+** But there is a good reason to not use the wrappers.  If we use the
+** wrappers then we will get simulated malloc() failures within this
+** driver.  And that causes all kinds of problems for our tests.  We
+** could enhance SQLite to deal with simulated malloc failures within
+** the OS driver, but the code to deal with those failure would not
+** be exercised on Linux (which does not need to malloc() in the driver)
+** and so we would have difficulty writing coverage tests for that
+** code.  Better to leave the code out, we think.
+**
+** The point of this discussion is as follows:  When creating a new
+** OS layer for an embedded system, if you use this file as an example,
+** avoid the use of malloc()/free().  Those routines work ok on OS/2
+** desktops but not so well in embedded systems.
+*/
+
+/*
+** Macros used to determine whether or not to use threads.
+*/
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE
+# define SQLITE_OS2_THREADS 1
+#endif
+
+/*
+** Include code that is common to all os_*.c files
+*/
+#include "os_common.h"
+
+/*
+** The os2File structure is subclass of sqlite3_file specific for the OS/2
+** protability layer.
+*/
+typedef struct os2File os2File;
+struct os2File {
+  const sqlite3_io_methods *pMethod;  /* Always the first entry */
+  HFILE h;                  /* Handle for accessing the file */
+  char* pathToDel;          /* Name of file to delete on close, NULL if not */
+  unsigned char locktype;   /* Type of lock currently held on this file */
+};
+
+#define LOCK_TIMEOUT 10L /* the default locking timeout */
+
+/*****************************************************************************
+** The next group of routines implement the I/O methods specified
+** by the sqlite3_io_methods object.
+******************************************************************************/
+
+/*
+** Close a file.
+*/
+static int os2Close( sqlite3_file *id ){
+  APIRET rc = NO_ERROR;
+  os2File *pFile;
+  if( id && (pFile = (os2File*)id) != 0 ){
+    OSTRACE2( "CLOSE %d\n", pFile->h );
+    rc = DosClose( pFile->h );
+    pFile->locktype = NO_LOCK;
+    if( pFile->pathToDel != NULL ){
+      rc = DosForceDelete( (PSZ)pFile->pathToDel );
+      free( pFile->pathToDel );
+      pFile->pathToDel = NULL;
+    }
+    id = 0;
+    OpenCounter( -1 );
+  }
+
+  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
+}
+
+/*
+** Read data from a file into a buffer.  Return SQLITE_OK if all
+** bytes were read successfully and SQLITE_IOERR if anything goes
+** wrong.
+*/
+static int os2Read(
+  sqlite3_file *id,               /* File to read from */
+  void *pBuf,                     /* Write content into this buffer */
+  int amt,                        /* Number of bytes to read */
+  sqlite3_int64 offset            /* Begin reading at this offset */
+){
+  ULONG fileLocation = 0L;
+  ULONG got;
+  os2File *pFile = (os2File*)id;
+  assert( id!=0 );
+  SimulateIOError( return SQLITE_IOERR_READ );
+  OSTRACE3( "READ %d lock=%d\n", pFile->h, pFile->locktype );
+  if( DosSetFilePtr(pFile->h, offset, FILE_BEGIN, &fileLocation) != NO_ERROR ){
+    return SQLITE_IOERR;
+  }
+  if( DosRead( pFile->h, pBuf, amt, &got ) != NO_ERROR ){
+    return SQLITE_IOERR_READ;
+  }
+  if( got == (ULONG)amt )
+    return SQLITE_OK;
+  else {
+    memset(&((char*)pBuf)[got], 0, amt-got);
+    return SQLITE_IOERR_SHORT_READ;
+  }
+}
+
+/*
+** Write data from a buffer into a file.  Return SQLITE_OK on success
+** or some other error code on failure.
+*/
+static int os2Write(
+  sqlite3_file *id,               /* File to write into */
+  const void *pBuf,               /* The bytes to be written */
+  int amt,                        /* Number of bytes to write */
+  sqlite3_int64 offset            /* Offset into the file to begin writing at */
+){
+  ULONG fileLocation = 0L;
+  APIRET rc = NO_ERROR;
+  ULONG wrote;
+  os2File *pFile = (os2File*)id;
+  assert( id!=0 );
+  SimulateIOError( return SQLITE_IOERR_WRITE );
+  SimulateDiskfullError( return SQLITE_FULL );
+  OSTRACE3( "WRITE %d lock=%d\n", pFile->h, pFile->locktype );
+  if( DosSetFilePtr(pFile->h, offset, FILE_BEGIN, &fileLocation) != NO_ERROR ){
+    return SQLITE_IOERR;
+  }
+  assert( amt>0 );
+  while( amt > 0 &&
+         ( rc = DosWrite( pFile->h, (PVOID)pBuf, amt, &wrote ) ) == NO_ERROR &&
+         wrote > 0
+  ){
+    amt -= wrote;
+    pBuf = &((char*)pBuf)[wrote];
+  }
+
+  return ( rc != NO_ERROR || amt > (int)wrote ) ? SQLITE_FULL : SQLITE_OK;
+}
+
+/*
+** Truncate an open file to a specified size
+*/
+static int os2Truncate( sqlite3_file *id, i64 nByte ){
+  APIRET rc = NO_ERROR;
+  os2File *pFile = (os2File*)id;
+  OSTRACE3( "TRUNCATE %d %lld\n", pFile->h, nByte );
+  SimulateIOError( return SQLITE_IOERR_TRUNCATE );
+  rc = DosSetFileSize( pFile->h, nByte );
+  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
+}
+
+#ifdef SQLITE_TEST
+/*
+** Count the number of fullsyncs and normal syncs.  This is used to test
+** that syncs and fullsyncs are occuring at the right times.
+*/
+int sqlite3_sync_count = 0;
+int sqlite3_fullsync_count = 0;
+#endif
+
+/*
+** Make sure all writes to a particular file are committed to disk.
+*/
+static int os2Sync( sqlite3_file *id, int flags ){
+  os2File *pFile = (os2File*)id;
+  OSTRACE3( "SYNC %d lock=%d\n", pFile->h, pFile->locktype );
+#ifdef SQLITE_TEST
+  if( flags & SQLITE_SYNC_FULL){
+    sqlite3_fullsync_count++;
+  }
+  sqlite3_sync_count++;
+#endif
+  return DosResetBuffer( pFile->h ) == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
+}
+
+/*
+** Determine the current size of a file in bytes
+*/
+static int os2FileSize( sqlite3_file *id, sqlite3_int64 *pSize ){
+  APIRET rc = NO_ERROR;
+  FILESTATUS3 fsts3FileInfo;
+  memset(&fsts3FileInfo, 0, sizeof(fsts3FileInfo));
+  assert( id!=0 );
+  SimulateIOError( return SQLITE_IOERR );
+  rc = DosQueryFileInfo( ((os2File*)id)->h, FIL_STANDARD, &fsts3FileInfo, sizeof(FILESTATUS3) );
+  if( rc == NO_ERROR ){
+    *pSize = fsts3FileInfo.cbFile;
+    return SQLITE_OK;
+  }else{
+    return SQLITE_IOERR;
+  }
+}
+
+/*
+** Acquire a reader lock.
+*/
+static int getReadLock( os2File *pFile ){
+  FILELOCK  LockArea,
+            UnlockArea;
+  APIRET res;
+  memset(&LockArea, 0, sizeof(LockArea));
+  memset(&UnlockArea, 0, sizeof(UnlockArea));
+  LockArea.lOffset = SHARED_FIRST;
+  LockArea.lRange = SHARED_SIZE;
+  UnlockArea.lOffset = 0L;
+  UnlockArea.lRange = 0L;
+  res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 1L );
+  OSTRACE3( "GETREADLOCK %d res=%d\n", pFile->h, res );
+  return res;
+}
+
+/*
+** Undo a readlock
+*/
+static int unlockReadLock( os2File *id ){
+  FILELOCK  LockArea,
+            UnlockArea;
+  APIRET res;
+  memset(&LockArea, 0, sizeof(LockArea));
+  memset(&UnlockArea, 0, sizeof(UnlockArea));
+  LockArea.lOffset = 0L;
+  LockArea.lRange = 0L;
+  UnlockArea.lOffset = SHARED_FIRST;
+  UnlockArea.lRange = SHARED_SIZE;
+  res = DosSetFileLocks( id->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 1L );
+  OSTRACE3( "UNLOCK-READLOCK file handle=%d res=%d?\n", id->h, res );
+  return res;
+}
+
+/*
+** Lock the file with the lock specified by parameter locktype - one
+** of the following:
+**
+**     (1) SHARED_LOCK
+**     (2) RESERVED_LOCK
+**     (3) PENDING_LOCK
+**     (4) EXCLUSIVE_LOCK
+**
+** Sometimes when requesting one lock state, additional lock states
+** are inserted in between.  The locking might fail on one of the later
+** transitions leaving the lock state different from what it started but
+** still short of its goal.  The following chart shows the allowed
+** transitions and the inserted intermediate states:
+**
+**    UNLOCKED -> SHARED
+**    SHARED -> RESERVED
+**    SHARED -> (PENDING) -> EXCLUSIVE
+**    RESERVED -> (PENDING) -> EXCLUSIVE
+**    PENDING -> EXCLUSIVE
+**
+** This routine will only increase a lock.  The os2Unlock() routine
+** erases all locks at once and returns us immediately to locking level 0.
+** It is not possible to lower the locking level one step at a time.  You
+** must go straight to locking level 0.
+*/
+static int os2Lock( sqlite3_file *id, int locktype ){
+  int rc = SQLITE_OK;       /* Return code from subroutines */
+  APIRET res = NO_ERROR;    /* Result of an OS/2 lock call */
+  int newLocktype;       /* Set pFile->locktype to this value before exiting */
+  int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
+  FILELOCK  LockArea,
+            UnlockArea;
+  os2File *pFile = (os2File*)id;
+  memset(&LockArea, 0, sizeof(LockArea));
+  memset(&UnlockArea, 0, sizeof(UnlockArea));
+  assert( pFile!=0 );
+  OSTRACE4( "LOCK %d %d was %d\n", pFile->h, locktype, pFile->locktype );
+
+  /* If there is already a lock of this type or more restrictive on the
+  ** os2File, do nothing. Don't use the end_lock: exit path, as
+  ** sqlite3_mutex_enter() hasn't been called yet.
+  */
+  if( pFile->locktype>=locktype ){
+    OSTRACE3( "LOCK %d %d ok (already held)\n", pFile->h, locktype );
+    return SQLITE_OK;
+  }
+
+  /* Make sure the locking sequence is correct
+  */
+  assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
+  assert( locktype!=PENDING_LOCK );
+  assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );
+
+  /* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
+  ** a SHARED lock.  If we are acquiring a SHARED lock, the acquisition of
+  ** the PENDING_LOCK byte is temporary.
+  */
+  newLocktype = pFile->locktype;
+  if( pFile->locktype==NO_LOCK
+      || (locktype==EXCLUSIVE_LOCK && pFile->locktype==RESERVED_LOCK)
+  ){
+    LockArea.lOffset = PENDING_BYTE;
+    LockArea.lRange = 1L;
+    UnlockArea.lOffset = 0L;
+    UnlockArea.lRange = 0L;
+
+    /* wait longer than LOCK_TIMEOUT here not to have to try multiple times */
+    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 100L, 0L );
+    if( res == NO_ERROR ){
+      gotPendingLock = 1;
+      OSTRACE3( "LOCK %d pending lock boolean set.  res=%d\n", pFile->h, res );
+    }
+  }
+
+  /* Acquire a shared lock
+  */
+  if( locktype==SHARED_LOCK && res == NO_ERROR ){
+    assert( pFile->locktype==NO_LOCK );
+    res = getReadLock(pFile);
+    if( res == NO_ERROR ){
+      newLocktype = SHARED_LOCK;
+    }
+    OSTRACE3( "LOCK %d acquire shared lock. res=%d\n", pFile->h, res );
+  }
+
+  /* Acquire a RESERVED lock
+  */
+  if( locktype==RESERVED_LOCK && res == NO_ERROR ){
+    assert( pFile->locktype==SHARED_LOCK );
+    LockArea.lOffset = RESERVED_BYTE;
+    LockArea.lRange = 1L;
+    UnlockArea.lOffset = 0L;
+    UnlockArea.lRange = 0L;
+    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
+    if( res == NO_ERROR ){
+      newLocktype = RESERVED_LOCK;
+    }
+    OSTRACE3( "LOCK %d acquire reserved lock. res=%d\n", pFile->h, res );
+  }
+
+  /* Acquire a PENDING lock
+  */
+  if( locktype==EXCLUSIVE_LOCK && res == NO_ERROR ){
+    newLocktype = PENDING_LOCK;
+    gotPendingLock = 0;
+    OSTRACE2( "LOCK %d acquire pending lock. pending lock boolean unset.\n", pFile->h );
+  }
+
+  /* Acquire an EXCLUSIVE lock
+  */
+  if( locktype==EXCLUSIVE_LOCK && res == NO_ERROR ){
+    assert( pFile->locktype>=SHARED_LOCK );
+    res = unlockReadLock(pFile);
+    OSTRACE2( "unreadlock = %d\n", res );
+    LockArea.lOffset = SHARED_FIRST;
+    LockArea.lRange = SHARED_SIZE;
+    UnlockArea.lOffset = 0L;
+    UnlockArea.lRange = 0L;
+    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
+    if( res == NO_ERROR ){
+      newLocktype = EXCLUSIVE_LOCK;
+    }else{
+      OSTRACE2( "OS/2 error-code = %d\n", res );
+      getReadLock(pFile);
+    }
+    OSTRACE3( "LOCK %d acquire exclusive lock.  res=%d\n", pFile->h, res );
+  }
+
+  /* If we are holding a PENDING lock that ought to be released, then
+  ** release it now.
+  */
+  if( gotPendingLock && locktype==SHARED_LOCK ){
+    int r;
+    LockArea.lOffset = 0L;
+    LockArea.lRange = 0L;
+    UnlockArea.lOffset = PENDING_BYTE;
+    UnlockArea.lRange = 1L;
+    r = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
+    OSTRACE3( "LOCK %d unlocking pending/is shared. r=%d\n", pFile->h, r );
+  }
+
+  /* Update the state of the lock has held in the file descriptor then
+  ** return the appropriate result code.
+  */
+  if( res == NO_ERROR ){
+    rc = SQLITE_OK;
+  }else{
+    OSTRACE4( "LOCK FAILED %d trying for %d but got %d\n", pFile->h,
+              locktype, newLocktype );
+    rc = SQLITE_BUSY;
+  }
+  pFile->locktype = newLocktype;
+  OSTRACE3( "LOCK %d now %d\n", pFile->h, pFile->locktype );
+  return rc;
+}
+
+/*
+** This routine checks if there is a RESERVED lock held on the specified
+** file by this or any other process. If such a lock is held, return
+** non-zero, otherwise zero.
+*/
+static int os2CheckReservedLock( sqlite3_file *id, int *pOut ){
+  int r = 0;
+  os2File *pFile = (os2File*)id;
+  assert( pFile!=0 );
+  if( pFile->locktype>=RESERVED_LOCK ){
+    r = 1;
+    OSTRACE3( "TEST WR-LOCK %d %d (local)\n", pFile->h, r );
+  }else{
+    FILELOCK  LockArea,
+              UnlockArea;
+    APIRET rc = NO_ERROR;
+    memset(&LockArea, 0, sizeof(LockArea));
+    memset(&UnlockArea, 0, sizeof(UnlockArea));
+    LockArea.lOffset = RESERVED_BYTE;
+    LockArea.lRange = 1L;
+    UnlockArea.lOffset = 0L;
+    UnlockArea.lRange = 0L;
+    rc = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
+    OSTRACE3( "TEST WR-LOCK %d lock reserved byte rc=%d\n", pFile->h, rc );
+    if( rc == NO_ERROR ){
+      APIRET rcu = NO_ERROR; /* return code for unlocking */
+      LockArea.lOffset = 0L;
+      LockArea.lRange = 0L;
+      UnlockArea.lOffset = RESERVED_BYTE;
+      UnlockArea.lRange = 1L;
+      rcu = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
+      OSTRACE3( "TEST WR-LOCK %d unlock reserved byte r=%d\n", pFile->h, rcu );
+    }
+    r = !(rc == NO_ERROR);
+    OSTRACE3( "TEST WR-LOCK %d %d (remote)\n", pFile->h, r );
+  }
+  *pOut = r;
+  return SQLITE_OK;
+}
+
+/*
+** Lower the locking level on file descriptor id to locktype.  locktype
+** must be either NO_LOCK or SHARED_LOCK.
+**
+** If the locking level of the file descriptor is already at or below
+** the requested locking level, this routine is a no-op.
+**
+** It is not possible for this routine to fail if the second argument
+** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine
+** might return SQLITE_IOERR;
+*/
+static int os2Unlock( sqlite3_file *id, int locktype ){
+  int type;
+  os2File *pFile = (os2File*)id;
+  APIRET rc = SQLITE_OK;
+  APIRET res = NO_ERROR;
+  FILELOCK  LockArea,
+            UnlockArea;
+  memset(&LockArea, 0, sizeof(LockArea));
+  memset(&UnlockArea, 0, sizeof(UnlockArea));
+  assert( pFile!=0 );
+  assert( locktype<=SHARED_LOCK );
+  OSTRACE4( "UNLOCK %d to %d was %d\n", pFile->h, locktype, pFile->locktype );
+  type = pFile->locktype;
+  if( type>=EXCLUSIVE_LOCK ){
+    LockArea.lOffset = 0L;
+    LockArea.lRange = 0L;
+    UnlockArea.lOffset = SHARED_FIRST;
+    UnlockArea.lRange = SHARED_SIZE;
+    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
+    OSTRACE3( "UNLOCK %d exclusive lock res=%d\n", pFile->h, res );
+    if( locktype==SHARED_LOCK && getReadLock(pFile) != NO_ERROR ){
+      /* This should never happen.  We should always be able to
+      ** reacquire the read lock */
+      OSTRACE3( "UNLOCK %d to %d getReadLock() failed\n", pFile->h, locktype );
+      rc = SQLITE_IOERR_UNLOCK;
+    }
+  }
+  if( type>=RESERVED_LOCK ){
+    LockArea.lOffset = 0L;
+    LockArea.lRange = 0L;
+    UnlockArea.lOffset = RESERVED_BYTE;
+    UnlockArea.lRange = 1L;
+    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
+    OSTRACE3( "UNLOCK %d reserved res=%d\n", pFile->h, res );
+  }
+  if( locktype==NO_LOCK && type>=SHARED_LOCK ){
+    res = unlockReadLock(pFile);
+    OSTRACE5( "UNLOCK %d is %d want %d res=%d\n", pFile->h, type, locktype, res );
+  }
+  if( type>=PENDING_LOCK ){
+    LockArea.lOffset = 0L;
+    LockArea.lRange = 0L;
+    UnlockArea.lOffset = PENDING_BYTE;
+    UnlockArea.lRange = 1L;
+    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
+    OSTRACE3( "UNLOCK %d pending res=%d\n", pFile->h, res );
+  }
+  pFile->locktype = locktype;
+  OSTRACE3( "UNLOCK %d now %d\n", pFile->h, pFile->locktype );
+  return rc;
+}
+
+/*
+** Control and query of the open file handle.
+*/
+static int os2FileControl(sqlite3_file *id, int op, void *pArg){
+  switch( op ){
+    case SQLITE_FCNTL_LOCKSTATE: {
+      *(int*)pArg = ((os2File*)id)->locktype;
+      OSTRACE3( "FCNTL_LOCKSTATE %d lock=%d\n", ((os2File*)id)->h, ((os2File*)id)->locktype );
+      return SQLITE_OK;
+    }
+  }
+  return SQLITE_ERROR;
+}
+
+/*
+** Return the sector size in bytes of the underlying block device for
+** the specified file. This is almost always 512 bytes, but may be
+** larger for some devices.
+**
+** SQLite code assumes this function cannot fail. It also assumes that
+** if two files are created in the same file-system directory (i.e.
+** a database and its journal file) that the sector size will be the
+** same for both.
+*/
+static int os2SectorSize(sqlite3_file *id){
+  return SQLITE_DEFAULT_SECTOR_SIZE;
+}
+
+/*
+** Return a vector of device characteristics.
+*/
+static int os2DeviceCharacteristics(sqlite3_file *id){
+  return 0;
+}
+
+
+/*
+** Character set conversion objects used by conversion routines.
+*/
+static UconvObject ucUtf8 = NULL; /* convert between UTF-8 and UCS-2 */
+static UconvObject uclCp = NULL;  /* convert between local codepage and UCS-2 */
+
+/*
+** Helper function to initialize the conversion objects from and to UTF-8.
+*/
+static void initUconvObjects( void ){
+  if( UniCreateUconvObject( UTF_8, &ucUtf8 ) != ULS_SUCCESS )
+    ucUtf8 = NULL;
+  if ( UniCreateUconvObject( (UniChar *)L"@path=yes", &uclCp ) != ULS_SUCCESS )
+    uclCp = NULL;
+}
+
+/*
+** Helper function to free the conversion objects from and to UTF-8.
+*/
+static void freeUconvObjects( void ){
+  if ( ucUtf8 )
+    UniFreeUconvObject( ucUtf8 );
+  if ( uclCp )
+    UniFreeUconvObject( uclCp );
+  ucUtf8 = NULL;
+  uclCp = NULL;
+}
+
+/*
+** Helper function to convert UTF-8 filenames to local OS/2 codepage.
+** The two-step process: first convert the incoming UTF-8 string
+** into UCS-2 and then from UCS-2 to the current codepage.
+** The returned char pointer has to be freed.
+*/
+static char *convertUtf8PathToCp( const char *in ){
+  UniChar tempPath[CCHMAXPATH];
+  char *out = (char *)calloc( CCHMAXPATH, 1 );
+
+  if( !out )
+    return NULL;
+
+  if( !ucUtf8 || !uclCp )
+    initUconvObjects();
+
+  /* determine string for the conversion of UTF-8 which is CP1208 */
+  if( UniStrToUcs( ucUtf8, tempPath, (char *)in, CCHMAXPATH ) != ULS_SUCCESS )
+    return out; /* if conversion fails, return the empty string */
+
+  /* conversion for current codepage which can be used for paths */
+  UniStrFromUcs( uclCp, out, tempPath, CCHMAXPATH );
+
+  return out;
+}
+
+/*
+** Helper function to convert filenames from local codepage to UTF-8.
+** The two-step process: first convert the incoming codepage-specific
+** string into UCS-2 and then from UCS-2 to the codepage of UTF-8.
+** The returned char pointer has to be freed.
+**
+** This function is non-static to be able to use this in shell.c and
+** similar applications that take command line arguments.
+*/
+char *convertCpPathToUtf8( const char *in ){
+  UniChar tempPath[CCHMAXPATH];
+  char *out = (char *)calloc( CCHMAXPATH, 1 );
+
+  if( !out )
+    return NULL;
+
+  if( !ucUtf8 || !uclCp )
+    initUconvObjects();
+
+  /* conversion for current codepage which can be used for paths */
+  if( UniStrToUcs( uclCp, tempPath, (char *)in, CCHMAXPATH ) != ULS_SUCCESS )
+    return out; /* if conversion fails, return the empty string */
+
+  /* determine string for the conversion of UTF-8 which is CP1208 */
+  UniStrFromUcs( ucUtf8, out, tempPath, CCHMAXPATH );
+
+  return out;
+}
+
+/*
+** This vector defines all the methods that can operate on an
+** sqlite3_file for os2.
+*/
+static const sqlite3_io_methods os2IoMethod = {
+  1,                        /* iVersion */
+  os2Close,
+  os2Read,
+  os2Write,
+  os2Truncate,
+  os2Sync,
+  os2FileSize,
+  os2Lock,
+  os2Unlock,
+  os2CheckReservedLock,
+  os2FileControl,
+  os2SectorSize,
+  os2DeviceCharacteristics
+};
+
+/***************************************************************************
+** Here ends the I/O methods that form the sqlite3_io_methods object.
+**
+** The next block of code implements the VFS methods.
+****************************************************************************/
+
+/*
+** Create a temporary file name in zBuf.  zBuf must be big enough to
+** hold at pVfs->mxPathname characters.
+*/
+static int getTempname(int nBuf, char *zBuf ){
+  static const unsigned char zChars[] =
+    "abcdefghijklmnopqrstuvwxyz"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+    "0123456789";
+  int i, j;
+  char zTempPathBuf[3];
+  PSZ zTempPath = (PSZ)&zTempPathBuf;
+  if( sqlite3_temp_directory ){
+    zTempPath = sqlite3_temp_directory;
+  }else{
+    if( DosScanEnv( (PSZ)"TEMP", &zTempPath ) ){
+      if( DosScanEnv( (PSZ)"TMP", &zTempPath ) ){
+        if( DosScanEnv( (PSZ)"TMPDIR", &zTempPath ) ){
+           ULONG ulDriveNum = 0, ulDriveMap = 0;
+           DosQueryCurrentDisk( &ulDriveNum, &ulDriveMap );
+           sprintf( (char*)zTempPath, "%c:", (char)( 'A' + ulDriveNum - 1 ) );
+        }
+      }
+    }
+  }
+  /* Strip off a trailing slashes or backslashes, otherwise we would get *
+   * multiple (back)slashes which causes DosOpen() to fail.              *
+   * Trailing spaces are not allowed, either.                            */
+  j = strlen(zTempPath);
+  while( j > 0 && ( zTempPath[j-1] == '\\' || zTempPath[j-1] == '/'
+                    || zTempPath[j-1] == ' ' ) ){
+    j--;
+  }
+  zTempPath[j] = '\0';
+  if( !sqlite3_temp_directory ){
+    char *zTempPathUTF = convertCpPathToUtf8( zTempPath );
+    sqlite3_snprintf( nBuf-30, zBuf,
+                      "%s\\"SQLITE_TEMP_FILE_PREFIX, zTempPathUTF );
+    free( zTempPathUTF );
+  }else{
+    sqlite3_snprintf( nBuf-30, zBuf,
+                      "%s\\"SQLITE_TEMP_FILE_PREFIX, zTempPath );
+  }
+  j = strlen( zBuf );
+  sqlite3_randomness( 20, &zBuf[j] );
+  for( i = 0; i < 20; i++, j++ ){
+    zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
+  }
+  zBuf[j] = 0;
+  OSTRACE2( "TEMP FILENAME: %s\n", zBuf );
+  return SQLITE_OK;
+}
+
+
+/*
+** Turn a relative pathname into a full pathname.  Write the full
+** pathname into zFull[].  zFull[] will be at least pVfs->mxPathname
+** bytes in size.
+*/
+static int os2FullPathname(
+  sqlite3_vfs *pVfs,          /* Pointer to vfs object */
+  const char *zRelative,      /* Possibly relative input path */
+  int nFull,                  /* Size of output buffer in bytes */
+  char *zFull                 /* Output buffer */
+){
+  char *zRelativeCp = convertUtf8PathToCp( zRelative );
+  char zFullCp[CCHMAXPATH] = "\0";
+  char *zFullUTF;
+  APIRET rc = DosQueryPathInfo( zRelativeCp, FIL_QUERYFULLNAME, zFullCp,
+                                CCHMAXPATH );
+  free( zRelativeCp );
+  zFullUTF = convertCpPathToUtf8( zFullCp );
+  sqlite3_snprintf( nFull, zFull, zFullUTF );
+  free( zFullUTF );
+  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
+}
+
+
+/*
+** Open a file.
+*/
+static int os2Open(
+  sqlite3_vfs *pVfs,            /* Not used */
+  const char *zName,            /* Name of the file */
+  sqlite3_file *id,             /* Write the SQLite file handle here */
+  int flags,                    /* Open mode flags */
+  int *pOutFlags                /* Status return flags */
+){
+  HFILE h;
+  ULONG ulFileAttribute = 0;
+  ULONG ulOpenFlags = 0;
+  ULONG ulOpenMode = 0;
+  os2File *pFile = (os2File*)id;
+  APIRET rc = NO_ERROR;
+  ULONG ulAction;
+  char *zNameCp;
+  char zTmpname[CCHMAXPATH+1];    /* Buffer to hold name of temp file */
+
+  /* If the second argument to this function is NULL, generate a 
+  ** temporary file name to use 
+  */
+  if( !zName ){
+    int rc = getTempname(CCHMAXPATH+1, zTmpname);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    zName = zTmpname;
+  }
+
+
+  memset( pFile, 0, sizeof(*pFile) );
+
+  OSTRACE2( "OPEN want %d\n", flags );
+
+  /*ulOpenMode = flags & SQLITE_OPEN_READWRITE ? OPEN_ACCESS_READWRITE : OPEN_ACCESS_READONLY;*/
+  if( flags & SQLITE_OPEN_READWRITE ){
+    ulOpenMode |= OPEN_ACCESS_READWRITE;
+    OSTRACE1( "OPEN read/write\n" );
+  }else{
+    ulOpenMode |= OPEN_ACCESS_READONLY;
+    OSTRACE1( "OPEN read only\n" );
+  }
+
+  /*ulOpenFlags = flags & SQLITE_OPEN_CREATE ? OPEN_ACTION_CREATE_IF_NEW : OPEN_ACTION_FAIL_IF_NEW;*/
+  if( flags & SQLITE_OPEN_CREATE ){
+    ulOpenFlags |= OPEN_ACTION_OPEN_IF_EXISTS | OPEN_ACTION_CREATE_IF_NEW;
+    OSTRACE1( "OPEN open new/create\n" );
+  }else{
+    ulOpenFlags |= OPEN_ACTION_OPEN_IF_EXISTS | OPEN_ACTION_FAIL_IF_NEW;
+    OSTRACE1( "OPEN open existing\n" );
+  }
+
+  /*ulOpenMode |= flags & SQLITE_OPEN_MAIN_DB ? OPEN_SHARE_DENYNONE : OPEN_SHARE_DENYWRITE;*/
+  if( flags & SQLITE_OPEN_MAIN_DB ){
+    ulOpenMode |= OPEN_SHARE_DENYNONE;
+    OSTRACE1( "OPEN share read/write\n" );
+  }else{
+    ulOpenMode |= OPEN_SHARE_DENYWRITE;
+    OSTRACE1( "OPEN share read only\n" );
+  }
+
+  if( flags & (SQLITE_OPEN_TEMP_DB | SQLITE_OPEN_TEMP_JOURNAL
+               | SQLITE_OPEN_SUBJOURNAL) ){
+    char pathUtf8[CCHMAXPATH];
+#ifdef NDEBUG /* when debugging we want to make sure it is deleted */
+    ulFileAttribute = FILE_HIDDEN;
+#endif
+    ulFileAttribute = FILE_NORMAL;
+    os2FullPathname( pVfs, zName, CCHMAXPATH, pathUtf8 );
+    pFile->pathToDel = convertUtf8PathToCp( pathUtf8 );
+    OSTRACE1( "OPEN hidden/delete on close file attributes\n" );
+  }else{
+    ulFileAttribute = FILE_ARCHIVED | FILE_NORMAL;
+    pFile->pathToDel = NULL;
+    OSTRACE1( "OPEN normal file attribute\n" );
+  }
+
+  /* always open in random access mode for possibly better speed */
+  ulOpenMode |= OPEN_FLAGS_RANDOM;
+  ulOpenMode |= OPEN_FLAGS_FAIL_ON_ERROR;
+  ulOpenMode |= OPEN_FLAGS_NOINHERIT;
+
+  zNameCp = convertUtf8PathToCp( zName );
+  rc = DosOpen( (PSZ)zNameCp,
+                &h,
+                &ulAction,
+                0L,
+                ulFileAttribute,
+                ulOpenFlags,
+                ulOpenMode,
+                (PEAOP2)NULL );
+  free( zNameCp );
+  if( rc != NO_ERROR ){
+    OSTRACE7( "OPEN Invalid handle rc=%d: zName=%s, ulAction=%#lx, ulAttr=%#lx, ulFlags=%#lx, ulMode=%#lx\n",
+              rc, zName, ulAction, ulFileAttribute, ulOpenFlags, ulOpenMode );
+    if( pFile->pathToDel )
+      free( pFile->pathToDel );
+    pFile->pathToDel = NULL;
+    if( flags & SQLITE_OPEN_READWRITE ){
+      OSTRACE2( "OPEN %d Invalid handle\n", ((flags | SQLITE_OPEN_READONLY) & ~SQLITE_OPEN_READWRITE) );
+      return os2Open( pVfs, zName, id,
+                      ((flags | SQLITE_OPEN_READONLY) & ~SQLITE_OPEN_READWRITE),
+                      pOutFlags );
+    }else{
+      return SQLITE_CANTOPEN;
+    }
+  }
+
+  if( pOutFlags ){
+    *pOutFlags = flags & SQLITE_OPEN_READWRITE ? SQLITE_OPEN_READWRITE : SQLITE_OPEN_READONLY;
+  }
+
+  pFile->pMethod = &os2IoMethod;
+  pFile->h = h;
+  OpenCounter(+1);
+  OSTRACE3( "OPEN %d pOutFlags=%d\n", pFile->h, pOutFlags );
+  return SQLITE_OK;
+}
+
+/*
+** Delete the named file.
+*/
+static int os2Delete(
+  sqlite3_vfs *pVfs,                     /* Not used on os2 */
+  const char *zFilename,                 /* Name of file to delete */
+  int syncDir                            /* Not used on os2 */
+){
+  APIRET rc = NO_ERROR;
+  char *zFilenameCp = convertUtf8PathToCp( zFilename );
+  SimulateIOError( return SQLITE_IOERR_DELETE );
+  rc = DosDelete( (PSZ)zFilenameCp );
+  free( zFilenameCp );
+  OSTRACE2( "DELETE \"%s\"\n", zFilename );
+  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
+}
+
+/*
+** Check the existance and status of a file.
+*/
+static int os2Access(
+  sqlite3_vfs *pVfs,        /* Not used on os2 */
+  const char *zFilename,    /* Name of file to check */
+  int flags,                /* Type of test to make on this file */
+  int *pOut                 /* Write results here */
+){
+  FILESTATUS3 fsts3ConfigInfo;
+  APIRET rc = NO_ERROR;
+  char *zFilenameCp = convertUtf8PathToCp( zFilename );
+
+  memset( &fsts3ConfigInfo, 0, sizeof(fsts3ConfigInfo) );
+  rc = DosQueryPathInfo( (PSZ)zFilenameCp, FIL_STANDARD,
+                         &fsts3ConfigInfo, sizeof(FILESTATUS3) );
+  free( zFilenameCp );
+  OSTRACE4( "ACCESS fsts3ConfigInfo.attrFile=%d flags=%d rc=%d\n",
+            fsts3ConfigInfo.attrFile, flags, rc );
+  switch( flags ){
+    case SQLITE_ACCESS_READ:
+    case SQLITE_ACCESS_EXISTS:
+      rc = (rc == NO_ERROR);
+      OSTRACE3( "ACCESS %s access of read and exists  rc=%d\n", zFilename, rc );
+      break;
+    case SQLITE_ACCESS_READWRITE:
+      rc = (rc == NO_ERROR) && ( (fsts3ConfigInfo.attrFile & FILE_READONLY) == 0 );
+      OSTRACE3( "ACCESS %s access of read/write  rc=%d\n", zFilename, rc );
+      break;
+    default:
+      assert( !"Invalid flags argument" );
+  }
+  *pOut = rc;
+  return SQLITE_OK;
+}
+
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+/*
+** Interfaces for opening a shared library, finding entry points
+** within the shared library, and closing the shared library.
+*/
+/*
+** Interfaces for opening a shared library, finding entry points
+** within the shared library, and closing the shared library.
+*/
+static void *os2DlOpen(sqlite3_vfs *pVfs, const char *zFilename){
+  UCHAR loadErr[256];
+  HMODULE hmod;
+  APIRET rc;
+  char *zFilenameCp = convertUtf8PathToCp(zFilename);
+  rc = DosLoadModule((PSZ)loadErr, sizeof(loadErr), zFilenameCp, &hmod);
+  free(zFilenameCp);
+  return rc != NO_ERROR ? 0 : (void*)hmod;
+}
+/*
+** A no-op since the error code is returned on the DosLoadModule call.
+** os2Dlopen returns zero if DosLoadModule is not successful.
+*/
+static void os2DlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
+/* no-op */
+}
+static void *os2DlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol){
+  PFN pfn;
+  APIRET rc;
+  rc = DosQueryProcAddr((HMODULE)pHandle, 0L, zSymbol, &pfn);
+  if( rc != NO_ERROR ){
+    /* if the symbol itself was not found, search again for the same
+     * symbol with an extra underscore, that might be needed depending
+     * on the calling convention */
+    char _zSymbol[256] = "_";
+    strncat(_zSymbol, zSymbol, 255);
+    rc = DosQueryProcAddr((HMODULE)pHandle, 0L, _zSymbol, &pfn);
+  }
+  return rc != NO_ERROR ? 0 : (void*)pfn;
+}
+static void os2DlClose(sqlite3_vfs *pVfs, void *pHandle){
+  DosFreeModule((HMODULE)pHandle);
+}
+#else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
+  #define os2DlOpen 0
+  #define os2DlError 0
+  #define os2DlSym 0
+  #define os2DlClose 0
+#endif
+
+
+/*
+** Write up to nBuf bytes of randomness into zBuf.
+*/
+static int os2Randomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf ){
+  ULONG sizeofULong = sizeof(ULONG);
+  int n = 0;
+  if( sizeof(DATETIME) <= nBuf - n ){
+    DATETIME x;
+    DosGetDateTime(&x);
+    memcpy(&zBuf[n], &x, sizeof(x));
+    n += sizeof(x);
+  }
+
+  if( sizeofULong <= nBuf - n ){
+    PPIB ppib;
+    DosGetInfoBlocks(NULL, &ppib);
+    memcpy(&zBuf[n], &ppib->pib_ulpid, sizeofULong);
+    n += sizeofULong;
+  }
+
+  if( sizeofULong <= nBuf - n ){
+    PTIB ptib;
+    DosGetInfoBlocks(&ptib, NULL);
+    memcpy(&zBuf[n], &ptib->tib_ptib2->tib2_ultid, sizeofULong);
+    n += sizeofULong;
+  }
+
+  /* if we still haven't filled the buffer yet the following will */
+  /* grab everything once instead of making several calls for a single item */
+  if( sizeofULong <= nBuf - n ){
+    ULONG ulSysInfo[QSV_MAX];
+    DosQuerySysInfo(1L, QSV_MAX, ulSysInfo, sizeofULong * QSV_MAX);
+
+    memcpy(&zBuf[n], &ulSysInfo[QSV_MS_COUNT - 1], sizeofULong);
+    n += sizeofULong;
+
+    if( sizeofULong <= nBuf - n ){
+      memcpy(&zBuf[n], &ulSysInfo[QSV_TIMER_INTERVAL - 1], sizeofULong);
+      n += sizeofULong;
+    }
+    if( sizeofULong <= nBuf - n ){
+      memcpy(&zBuf[n], &ulSysInfo[QSV_TIME_LOW - 1], sizeofULong);
+      n += sizeofULong;
+    }
+    if( sizeofULong <= nBuf - n ){
+      memcpy(&zBuf[n], &ulSysInfo[QSV_TIME_HIGH - 1], sizeofULong);
+      n += sizeofULong;
+    }
+    if( sizeofULong <= nBuf - n ){
+      memcpy(&zBuf[n], &ulSysInfo[QSV_TOTAVAILMEM - 1], sizeofULong);
+      n += sizeofULong;
+    }
+  }
+
+  return n;
+}
+
+/*
+** Sleep for a little while.  Return the amount of time slept.
+** The argument is the number of microseconds we want to sleep.
+** The return value is the number of microseconds of sleep actually
+** requested from the underlying operating system, a number which
+** might be greater than or equal to the argument, but not less
+** than the argument.
+*/
+static int os2Sleep( sqlite3_vfs *pVfs, int microsec ){
+  DosSleep( (microsec/1000) );
+  return microsec;
+}
+
+/*
+** The following variable, if set to a non-zero value, becomes the result
+** returned from sqlite3OsCurrentTime().  This is used for testing.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_current_time = 0;
+#endif
+
+/*
+** Find the current time (in Universal Coordinated Time).  Write the
+** current time and date as a Julian Day number into *prNow and
+** return 0.  Return 1 if the time and date cannot be found.
+*/
+int os2CurrentTime( sqlite3_vfs *pVfs, double *prNow ){
+  double now;
+  SHORT minute; /* needs to be able to cope with negative timezone offset */
+  USHORT second, hour,
+         day, month, year;
+  DATETIME dt;
+  DosGetDateTime( &dt );
+  second = (USHORT)dt.seconds;
+  minute = (SHORT)dt.minutes + dt.timezone;
+  hour = (USHORT)dt.hours;
+  day = (USHORT)dt.day;
+  month = (USHORT)dt.month;
+  year = (USHORT)dt.year;
+
+  /* Calculations from http://www.astro.keele.ac.uk/~rno/Astronomy/hjd.html
+     http://www.astro.keele.ac.uk/~rno/Astronomy/hjd-0.1.c */
+  /* Calculate the Julian days */
+  now = day - 32076 +
+    1461*(year + 4800 + (month - 14)/12)/4 +
+    367*(month - 2 - (month - 14)/12*12)/12 -
+    3*((year + 4900 + (month - 14)/12)/100)/4;
+
+  /* Add the fractional hours, mins and seconds */
+  now += (hour + 12.0)/24.0;
+  now += minute/1440.0;
+  now += second/86400.0;
+  *prNow = now;
+#ifdef SQLITE_TEST
+  if( sqlite3_current_time ){
+    *prNow = sqlite3_current_time/86400.0 + 2440587.5;
+  }
+#endif
+  return 0;
+}
+
+static int os2GetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
+  return 0;
+}
+
+/*
+** Initialize and deinitialize the operating system interface.
+*/
+int sqlite3_os_init(void){
+  static sqlite3_vfs os2Vfs = {
+    1,                 /* iVersion */
+    sizeof(os2File),   /* szOsFile */
+    CCHMAXPATH,        /* mxPathname */
+    0,                 /* pNext */
+    "os2",             /* zName */
+    0,                 /* pAppData */
+
+    os2Open,           /* xOpen */
+    os2Delete,         /* xDelete */
+    os2Access,         /* xAccess */
+    os2FullPathname,   /* xFullPathname */
+    os2DlOpen,         /* xDlOpen */
+    os2DlError,        /* xDlError */
+    os2DlSym,          /* xDlSym */
+    os2DlClose,        /* xDlClose */
+    os2Randomness,     /* xRandomness */
+    os2Sleep,          /* xSleep */
+    os2CurrentTime,    /* xCurrentTime */
+    os2GetLastError    /* xGetLastError */
+  };
+  sqlite3_vfs_register(&os2Vfs, 1);
+  initUconvObjects();
+  return SQLITE_OK;
+}
+int sqlite3_os_end(void){
+  freeUconvObjects();
+  return SQLITE_OK;
+}
+
+#endif /* SQLITE_OS_OS2 */
diff --git a/third_party/sqlite/src/os_symbian.cc b/third_party/sqlite/src/os_symbian.cc
new file mode 100755
index 0000000..5b86338
--- /dev/null
+++ b/third_party/sqlite/src/os_symbian.cc
@@ -0,0 +1,579 @@
+// Copyright 2008, Google Inc.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//  1. Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//  2. Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//  3. Neither the name of Google Inc. nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+// EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+// OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+// ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// This file contains code that is specific to Symbian.
+// Differently from the rest of SQLite, it is implemented in C++ as this is
+// the native language of the OS and all interfaces we need to use are C++.
+//
+// This file follows the Gears code style guidelines.
+
+#ifdef OS_SYMBIAN
+#include <coemain.h>
+#include <e32math.h>
+#include <f32file.h>
+#include <utf.h>
+
+extern "C" {
+#include "sqliteInt.h"
+#include "os_common.h"
+}
+
+const TInt kFileLockAttempts = 3;
+
+// The global file system session.
+RFs g_fs_session;
+
+static TInt UTF8ToUTF16(const char *in, TDes *out16) {
+  assert(in);
+  TPtrC8 in_des(reinterpret_cast<const unsigned char*>(in));
+  return CnvUtfConverter::ConvertToUnicodeFromUtf8(*out16, in_des);
+}
+
+static TInt UTF16ToUTF8(const TDesC16& in16, TDes8 *out8) {
+  return CnvUtfConverter::ConvertFromUnicodeToUtf8(*out8, in16);
+}
+
+// The SymbianFile structure is a subclass of sqlite3_file* specific to the
+// Symbian portability layer.
+struct SymbianFile {
+  const sqlite3_io_methods *methods;
+  RFile handle;              // The file handle
+  TUint8 lock_type;          // Type of lock currently held on this file
+  TUint16 shared_lock_byte;  // Randomly chosen byte used as a shared lock
+};
+
+static SymbianFile* ConvertToSymbianFile(sqlite3_file* const id) {
+  assert(id);
+  return reinterpret_cast<SymbianFile*>(id);
+}
+
+static int SymbianClose(sqlite3_file *id) {
+  SymbianFile *file_id = ConvertToSymbianFile(id);
+  file_id->handle.Close();
+  OpenCounter(-1);
+  return SQLITE_OK;
+}
+
+static int SymbianRead(sqlite3_file *id,
+                       void *buffer,
+                       int amount,
+                       sqlite3_int64 offset) {
+  assert(buffer);
+  assert(amount >=0);
+  assert(offset >=0);
+
+  SymbianFile* file_id = ConvertToSymbianFile(id);
+  TPtr8 dest(static_cast<unsigned char*>(buffer), amount);
+
+  if (KErrNone == file_id->handle.Read(offset, dest, amount)) {
+    if (dest.Length() == amount) {
+      return SQLITE_OK;
+    } else {
+      return SQLITE_IOERR_SHORT_READ;
+    }
+  } else {
+    return SQLITE_IOERR;
+  }
+}
+
+static int SymbianWrite(sqlite3_file *id,
+                        const void *buffer,
+                        int amount,
+                        sqlite3_int64 offset) {
+  assert(buffer);
+  assert(amount >=0);
+  assert(offset >=0);
+
+  SymbianFile *file_id = ConvertToSymbianFile(id);
+  TPtrC8 src(static_cast<const unsigned char*>(buffer), amount);
+  if (file_id->handle.Write(offset, src) != KErrNone) {
+    return SQLITE_IOERR_WRITE;
+  }
+
+  return SQLITE_OK;
+}
+
+static int SymbianTruncate(sqlite3_file *id, sqlite3_int64 bytes) {
+  assert(bytes >=0);
+
+  SymbianFile *file_id = ConvertToSymbianFile(id);
+  if (file_id->handle.SetSize(bytes) != KErrNone) {
+    return SQLITE_IOERR;
+  }
+  return SQLITE_OK;
+}
+
+static int SymbianSync(sqlite3_file *id, int /*flags*/) {
+  SymbianFile *file_id = ConvertToSymbianFile(id);
+  if (file_id->handle.Flush() != KErrNone) {
+    return SQLITE_IOERR;
+  } else {
+    return SQLITE_OK;
+  }
+}
+
+static int SymbianFileSize(sqlite3_file *id, sqlite3_int64 *size) {
+  assert(size);
+
+  SymbianFile *file_id = ConvertToSymbianFile(id);
+  TInt size_tmp;
+  if (file_id->handle.Size(size_tmp) != KErrNone) {
+    return SQLITE_IOERR;
+  }
+  *size = size_tmp;
+  return SQLITE_OK;
+}
+
+// File lock/unlock functions; see os_win.c for a description
+// of the algorithm used.
+static int GetReadLock(SymbianFile *file) {
+  file->shared_lock_byte = Math::Random() % (SHARED_SIZE - 1);
+  return file->handle.Lock(SHARED_FIRST + file->shared_lock_byte, 1);
+}
+
+static int UnlockReadLock(SymbianFile *file) {
+  return file->handle.UnLock(SHARED_FIRST + file->shared_lock_byte, 1);
+}
+
+static int SymbianLock(sqlite3_file *id, int lock_type) {
+  SymbianFile *file = ConvertToSymbianFile(id);
+  if (file->lock_type >= lock_type) {
+    return SQLITE_OK;
+  }
+
+  // Make sure the locking sequence is correct
+  assert(file->lock_type != NO_LOCK || lock_type == SHARED_LOCK);
+  assert(lock_type != PENDING_LOCK);
+  assert(lock_type != RESERVED_LOCK || file->lock_type == SHARED_LOCK);
+
+  // Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
+  // a SHARED lock.  If we are acquiring a SHARED lock, the acquisition of
+  // the PENDING_LOCK byte is temporary.
+  int new_lock_type = file->lock_type;
+  int got_pending_lock = 0;
+  int res = KErrNone;
+  if (file->lock_type == NO_LOCK ||
+         (lock_type == EXCLUSIVE_LOCK && file->lock_type == RESERVED_LOCK)) {
+    int count = kFileLockAttempts;
+    while (count-- > 0 &&
+        (res = file->handle.Lock(PENDING_BYTE, 1)) != KErrNone ) {
+      // Try 3 times to get the pending lock.  The pending lock might be
+      // held by another reader process who will release it momentarily.
+      OSTRACE2("could not get a PENDING lock. cnt=%d\n", cnt);
+      User::After(1000);
+    }
+    got_pending_lock = (res == KErrNone? 1 : 0);
+  }
+
+  // Acquire a shared lock
+  if (lock_type == SHARED_LOCK && res == KErrNone) {
+    assert(file->lock_type == NO_LOCK);
+    res = GetReadLock(file);
+    if (res == KErrNone) {
+      new_lock_type = SHARED_LOCK;
+    }
+  }
+
+  // Acquire a RESERVED lock
+  if (lock_type == RESERVED_LOCK && res == KErrNone) {
+    assert(file->lock_type == SHARED_LOCK);
+    res = file->handle.Lock(RESERVED_BYTE, 1);
+    if (res == KErrNone) {
+      new_lock_type = RESERVED_LOCK;
+    }
+  }
+
+  // Acquire a PENDING lock
+  if (lock_type == EXCLUSIVE_LOCK && res == KErrNone) {
+    new_lock_type = PENDING_LOCK;
+    got_pending_lock = 0;
+  }
+
+  // Acquire an EXCLUSIVE lock
+  if (lock_type == EXCLUSIVE_LOCK && res == KErrNone) {
+    assert(file->lock_type >= SHARED_LOCK);
+    res = UnlockReadLock(file);
+    OSTRACE2("unreadlock = %d\n", res);
+    res = file->handle.Lock(SHARED_FIRST, SHARED_SIZE);
+    if (res == KErrNone) {
+      new_lock_type = EXCLUSIVE_LOCK;
+    } else {
+      OSTRACE2("error-code = %d\n", GetLastError());
+      GetReadLock(file);
+    }
+  }
+
+  // If we are holding a PENDING lock that ought to be released, then
+  // release it now.
+  if (got_pending_lock && lock_type == SHARED_LOCK) {
+    file->handle.UnLock(PENDING_BYTE, 1);
+  }
+
+  // Update the state of the lock held in the file descriptor, then
+  // return the appropriate result code.
+  file->lock_type = new_lock_type;
+  if (res == KErrNone) {
+    return SQLITE_OK;
+  } else {
+    OSTRACE4("LOCK FAILED %d trying for %d but got %d\n", file->handle,
+           lock_type, new_lock_type);
+    return SQLITE_BUSY;
+  }
+}
+
+static int SymbianUnlock(sqlite3_file *id, int lock_type) {
+  int type;
+  int rc = SQLITE_OK;
+  SymbianFile *file = ConvertToSymbianFile(id);
+  assert(lock_type <= SHARED_LOCK);
+  OSTRACE5("UNLOCK %d to %d was %d(%d)\n", file->handle, lock_type,
+          file->lock_type, file->shared_lock_byte);
+  type = file->lock_type;
+  if (type >= EXCLUSIVE_LOCK) {
+    file->handle.UnLock(SHARED_FIRST, SHARED_SIZE);
+    if (lock_type == SHARED_LOCK && GetReadLock(file) != KErrNone) {
+      // This should never happen.  We should always be able to
+      // reacquire the read lock
+      rc = SQLITE_IOERR_UNLOCK;
+    }
+  }
+  if (type >= RESERVED_LOCK) {
+    file->handle.UnLock(RESERVED_BYTE, 1);
+  }
+  if (lock_type == NO_LOCK && type >= SHARED_LOCK) {
+    UnlockReadLock(file);
+  }
+  if (type >= PENDING_LOCK) {
+    file->handle.UnLock(PENDING_BYTE, 1);
+  }
+  file->lock_type = lock_type;
+  return rc;
+}
+
+static int SymbianCheckReservedLock(sqlite3_file *id, int *result) {
+  int rc;
+  SymbianFile *file = ConvertToSymbianFile(id);
+  if (file->lock_type >= RESERVED_LOCK) {
+    rc = 1;
+    OSTRACE3("TEST WR-LOCK %d %d (local)\n", pFile->h, rc);
+  } else {
+    rc = file->handle.Lock(RESERVED_BYTE, 1);
+    if (rc == KErrNone) {
+      file->handle.UnLock(RESERVED_BYTE, 1);
+    }
+    rc = !rc;
+    OSTRACE3("TEST WR-LOCK %d %d (remote)\n", file->handle, rc);
+  }
+  *result = rc;
+  return SQLITE_OK;
+}
+
+static int SymbianFileControl(sqlite3_file */*id*/,
+                              int /*op*/,
+                              void */*arg*/) {
+  return SQLITE_OK;
+}
+
+static int SymbianSectorSize(sqlite3_file */*id*/) {
+  return SQLITE_DEFAULT_SECTOR_SIZE;
+}
+
+static int SymbianDeviceCharacteristics(sqlite3_file */*id*/) {
+  return 0;
+}
+
+/*
+** This vector defines all the methods that can operate on a
+** sqlite3_file for Symbian.
+*/
+static const sqlite3_io_methods SymbianIoMethod = {
+  1,    // iVersion
+  SymbianClose,
+  SymbianRead,
+  SymbianWrite,
+  SymbianTruncate,
+  SymbianSync,
+  SymbianFileSize,
+  SymbianLock,
+  SymbianUnlock,
+  SymbianCheckReservedLock,
+  SymbianFileControl,
+  SymbianSectorSize,
+  SymbianDeviceCharacteristics
+};
+
+// ============================================================================
+// vfs methods begin here
+// ============================================================================
+static int SymbianOpen(sqlite3_vfs */*vfs*/,
+                       const char *name,
+                       sqlite3_file *id,
+                       int flags,
+                       int *out_flags) {
+  TUint desired_access;
+  TUint share_mode;
+  TInt err = KErrNone;
+  TFileName name_utf16;
+  SymbianFile *file = ConvertToSymbianFile(id);
+
+  if (out_flags) {
+    *out_flags = flags;
+  }
+
+  // if the name is NULL we have to open a temporary file.
+  if (!name) {
+    TPath private_path;
+    TFileName file_name;
+    if (g_fs_session.PrivatePath(private_path) != KErrNone) {
+      return SQLITE_CANTOPEN;
+    }
+    if (file->handle.Temp(g_fs_session,
+                          private_path,
+                          file_name,
+                          EFileWrite) !=
+        KErrNone) {
+      return SQLITE_CANTOPEN;
+    }
+    file->methods = &SymbianIoMethod;
+    file->lock_type = NO_LOCK;
+    file->shared_lock_byte = 0;
+    OpenCounter(+1);
+    return SQLITE_OK;
+  }
+
+  if (UTF8ToUTF16(name, &name_utf16) != KErrNone)
+    return SQLITE_CANTOPEN;
+
+  if (flags & SQLITE_OPEN_READWRITE) {
+    desired_access = EFileWrite;
+  } else {
+    desired_access = EFileRead;
+  }
+  if (flags & SQLITE_OPEN_MAIN_DB) {
+    share_mode = EFileShareReadersOrWriters;
+  } else {
+    share_mode = 0;
+  }
+
+  if (flags & SQLITE_OPEN_CREATE) {
+    err = file->handle.Create(g_fs_session,
+                              name_utf16,
+                              desired_access | share_mode);
+    if (err != KErrNone && err != KErrAlreadyExists) {
+      return SQLITE_CANTOPEN;
+    }
+  }
+
+  if (err != KErrNone) {
+    err = file->handle.Open(g_fs_session,
+                            name_utf16,
+                            desired_access | share_mode);
+    if (err != KErrNone && flags & SQLITE_OPEN_READWRITE) {
+      if (out_flags) {
+        *out_flags = (flags | SQLITE_OPEN_READONLY) & ~SQLITE_OPEN_READWRITE;
+      }
+      desired_access = EFileRead;
+      err = file->handle.Open(g_fs_session,
+                              name_utf16,
+                              desired_access | share_mode);
+    }
+    if (err != KErrNone) {
+      return SQLITE_CANTOPEN;
+    }
+  }
+  file->methods = &SymbianIoMethod;
+  file->lock_type = NO_LOCK;
+  file->shared_lock_byte = 0;
+  OpenCounter(+1);
+  return SQLITE_OK;
+}
+
+static int SymbianDelete(sqlite3_vfs */*vfs*/,
+                         const char *file_name,
+                         int /*sync_dir*/) {
+  assert(file_name);
+  TFileName file_name_utf16;
+
+  if (UTF8ToUTF16(file_name, &file_name_utf16) != KErrNone) {
+    return SQLITE_ERROR;
+  }
+
+  TInt result = g_fs_session.Delete(file_name_utf16);
+  return (result == KErrNone || result == KErrPathNotFound)?
+         SQLITE_OK : SQLITE_IOERR_DELETE;
+}
+
+static int SymbianAccess(sqlite3_vfs */*vfs*/,
+                         const char *file_name,
+                         int flags,
+                         int *result) {
+  assert(file_name);
+  TEntry entry;
+  TFileName file_name_utf16;
+
+  if (UTF8ToUTF16(file_name, &file_name_utf16) != KErrNone) {
+    return SQLITE_ERROR;
+  }
+
+  if (g_fs_session.Entry(file_name_utf16, entry) != KErrNone) {
+    *result = 0;
+    return SQLITE_OK;
+  }
+
+  switch (flags) {
+    case SQLITE_ACCESS_READ:
+    case SQLITE_ACCESS_EXISTS:
+      *result = !entry.IsDir();
+      break;
+    case SQLITE_ACCESS_READWRITE:
+      *result = !entry.IsDir() && !entry.IsReadOnly();
+      break;
+    default:
+      return SQLITE_ERROR;
+  }
+
+  return SQLITE_OK;
+}
+
+static int SymbianFullPathname(sqlite3_vfs */*vfs*/,
+                               const char *relative,
+                               int full_len,
+                               char *full) {
+  assert(relative);
+  assert(full);
+
+  TParse parse;
+  TPath relative_utf16;
+  TPath base_path;
+  TPtr8 full_utf8(reinterpret_cast<unsigned char*>(full), full_len);
+
+  g_fs_session.PrivatePath(base_path);
+
+  if (UTF8ToUTF16(relative, &relative_utf16) != KErrNone) {
+    return SQLITE_ERROR;
+  }
+
+  if (parse.Set(relative_utf16, &base_path, NULL) != KErrNone) {
+    return SQLITE_ERROR;
+  }
+
+  TDesC full_utf16(parse.FullName());
+  if (UTF16ToUTF8(relative_utf16, &full_utf8) != KErrNone) {
+    return SQLITE_ERROR;
+  }
+
+  full_utf8.PtrZ();
+  return SQLITE_OK;
+}
+
+static int SymbianRandomness(sqlite3_vfs */*vfs*/, int buf_len, char *buffer) {
+  assert(buffer);
+  TInt64 seed = User::TickCount();
+  for (TInt i = 0; i < buf_len; i++) {
+    buffer[i] = Math::Rand(seed) % 255;
+  }
+  return SQLITE_OK;
+}
+
+static int SymbianSleep(sqlite3_vfs */*vfs*/, int microsec) {
+  User::After(microsec);
+  return SQLITE_OK;
+}
+
+int SymbianCurrentTime(sqlite3_vfs */*vfs*/, double *now) {
+  _LIT(kEpoch, "19700101:000000.000000");
+  assert(now);
+  TTime time;
+  TTime epoch_time(kEpoch);
+  TTimeIntervalSeconds interval;
+
+  time.HomeTime();
+  // calculate seconds elapsed since 1-1-1970
+  time.SecondsFrom(epoch_time, interval);
+
+  // Julian date @ 1-1-1970 = 2440587.5
+  // seconds per day = 86400.0
+  *now = interval.Int()/86400.0 + 2440587.5;
+  return SQLITE_OK;
+}
+
+static int SymbianGetLastError(sqlite3_vfs */*vfs*/,
+                               int /*buf_len*/,
+                               char */*buf*/) {
+  assert(buf[0] == '\0');
+  return 0;
+}
+
+// Interfaces for opening a shared library, finding entry points
+// within the shared library, and closing the shared library.
+// TODO(marcogelmi): implement.
+#define SymbianDlOpen  0
+#define SymbianDlError 0
+#define SymbianDlSym   0
+#define SymbianDlClose 0
+
+// Initialize and deinitialize the operating system interface.
+int sqlite3_os_init(void) {
+  static sqlite3_vfs symbian_vfs = {
+    1,                     // iVersion
+    sizeof(SymbianFile),   // szOsFile
+    KMaxPath,              // mxPathname
+    0,                     // pNext
+    "symbian",             // name
+    0,                     // pAppData
+
+    SymbianOpen,           // xOpen
+    SymbianDelete,         // xDelete
+    SymbianAccess,         // xAccess
+    SymbianFullPathname,   // xFullPathname
+    SymbianDlOpen,         // xDlOpen
+    SymbianDlError,        // xDlError
+    SymbianDlSym,          // xDlSym
+    SymbianDlClose,        // xDlClose
+    SymbianRandomness,     // xRandomness
+    SymbianSleep,          // xSleep
+    SymbianCurrentTime,    // xCurrentTime
+    SymbianGetLastError    // xGetLastError
+  };
+
+  if (g_fs_session.Connect() != KErrNone) {
+    return SQLITE_ERROR;
+  }
+
+  if (g_fs_session.ShareAuto() != KErrNone) {
+    g_fs_session.Close();
+    return SQLITE_ERROR;
+  }
+
+  sqlite3_vfs_register(&symbian_vfs, 1);
+  return SQLITE_OK;
+}
+
+int sqlite3_os_end(void) {
+  g_fs_session.Close();
+  return SQLITE_OK;
+}
+
+#endif /* OS_SYMBIAN*/
diff --git a/third_party/sqlite/src/os_unix.c b/third_party/sqlite/src/os_unix.c
new file mode 100755
index 0000000..4874a64
--- /dev/null
+++ b/third_party/sqlite/src/os_unix.c
@@ -0,0 +1,2750 @@
+/*
+** 2004 May 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code that is specific to Unix systems.
+**
+** $Id: os_unix.c,v 1.195 2008/07/30 17:28:04 drh Exp $
+*/
+#include "sqliteInt.h"
+#if SQLITE_OS_UNIX              /* This file is used on unix only */
+
+/*
+** If SQLITE_ENABLE_LOCKING_STYLE is defined, then several different 
+** locking implementations are provided:
+**
+**   * POSIX locking (the default),
+**   * No locking,
+**   * Dot-file locking,
+**   * flock() locking,
+**   * AFP locking (OSX only).
+*/
+/* #define SQLITE_ENABLE_LOCKING_STYLE 0 */
+
+/*
+** These #defines should enable >2GB file support on Posix if the
+** underlying operating system supports it.  If the OS lacks
+** large file support, these should be no-ops.
+**
+** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
+** on the compiler command line.  This is necessary if you are compiling
+** on a recent machine (ex: RedHat 7.2) but you want your code to work
+** on an older machine (ex: RedHat 6.0).  If you compile on RedHat 7.2
+** without this option, LFS is enable.  But LFS does not exist in the kernel
+** in RedHat 6.0, so the code won't work.  Hence, for maximum binary
+** portability you should omit LFS.
+*/
+#ifndef SQLITE_DISABLE_LFS
+# define _LARGE_FILE       1
+# ifndef _FILE_OFFSET_BITS
+#   define _FILE_OFFSET_BITS 64
+# endif
+# define _LARGEFILE_SOURCE 1
+#endif
+
+/*
+** standard include files.
+*/
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/time.h>
+#include <errno.h>
+
+#ifdef SQLITE_ENABLE_LOCKING_STYLE
+#include <sys/ioctl.h>
+#include <sys/param.h>
+#include <sys/mount.h>
+#endif /* SQLITE_ENABLE_LOCKING_STYLE */
+
+/*
+** If we are to be thread-safe, include the pthreads header and define
+** the SQLITE_UNIX_THREADS macro.
+*/
+#if SQLITE_THREADSAFE
+# include <pthread.h>
+# define SQLITE_UNIX_THREADS 1
+#endif
+
+/*
+** Default permissions when creating a new file
+*/
+#ifndef SQLITE_DEFAULT_FILE_PERMISSIONS
+# define SQLITE_DEFAULT_FILE_PERMISSIONS 0644
+#endif
+
+/*
+** Maximum supported path-length.
+*/
+#define MAX_PATHNAME 512
+
+
+/*
+** The unixFile structure is subclass of sqlite3_file specific for the unix
+** protability layer.
+*/
+typedef struct unixFile unixFile;
+struct unixFile {
+  sqlite3_io_methods const *pMethod;  /* Always the first entry */
+#ifdef SQLITE_TEST
+  /* In test mode, increase the size of this structure a bit so that 
+  ** it is larger than the struct CrashFile defined in test6.c.
+  */
+  char aPadding[32];
+#endif
+  struct openCnt *pOpen;    /* Info about all open fd's on this inode */
+  struct lockInfo *pLock;   /* Info about locks on this inode */
+#ifdef SQLITE_ENABLE_LOCKING_STYLE
+  void *lockingContext;     /* Locking style specific state */
+#endif
+  int h;                    /* The file descriptor */
+  unsigned char locktype;   /* The type of lock held on this fd */
+  int dirfd;                /* File descriptor for the directory */
+#if SQLITE_THREADSAFE
+  pthread_t tid;            /* The thread that "owns" this unixFile */
+#endif
+};
+
+/*
+** Include code that is common to all os_*.c files
+*/
+#include "os_common.h"
+
+/*
+** Define various macros that are missing from some systems.
+*/
+#ifndef O_LARGEFILE
+# define O_LARGEFILE 0
+#endif
+#ifdef SQLITE_DISABLE_LFS
+# undef O_LARGEFILE
+# define O_LARGEFILE 0
+#endif
+#ifndef O_NOFOLLOW
+# define O_NOFOLLOW 0
+#endif
+#ifndef O_BINARY
+# define O_BINARY 0
+#endif
+
+/*
+** The DJGPP compiler environment looks mostly like Unix, but it
+** lacks the fcntl() system call.  So redefine fcntl() to be something
+** that always succeeds.  This means that locking does not occur under
+** DJGPP.  But it is DOS - what did you expect?
+*/
+#ifdef __DJGPP__
+# define fcntl(A,B,C) 0
+#endif
+
+/*
+** The threadid macro resolves to the thread-id or to 0.  Used for
+** testing and debugging only.
+*/
+#if SQLITE_THREADSAFE
+#define threadid pthread_self()
+#else
+#define threadid 0
+#endif
+
+/*
+** Set or check the unixFile.tid field.  This field is set when an unixFile
+** is first opened.  All subsequent uses of the unixFile verify that the
+** same thread is operating on the unixFile.  Some operating systems do
+** not allow locks to be overridden by other threads and that restriction
+** means that sqlite3* database handles cannot be moved from one thread
+** to another.  This logic makes sure a user does not try to do that
+** by mistake.
+**
+** Version 3.3.1 (2006-01-15):  unixFile can be moved from one thread to
+** another as long as we are running on a system that supports threads
+** overriding each others locks (which now the most common behavior)
+** or if no locks are held.  But the unixFile.pLock field needs to be
+** recomputed because its key includes the thread-id.  See the 
+** transferOwnership() function below for additional information
+*/
+#if SQLITE_THREADSAFE
+# define SET_THREADID(X)   (X)->tid = pthread_self()
+# define CHECK_THREADID(X) (threadsOverrideEachOthersLocks==0 && \
+                            !pthread_equal((X)->tid, pthread_self()))
+#else
+# define SET_THREADID(X)
+# define CHECK_THREADID(X) 0
+#endif
+
+/*
+** Here is the dirt on POSIX advisory locks:  ANSI STD 1003.1 (1996)
+** section 6.5.2.2 lines 483 through 490 specify that when a process
+** sets or clears a lock, that operation overrides any prior locks set
+** by the same process.  It does not explicitly say so, but this implies
+** that it overrides locks set by the same process using a different
+** file descriptor.  Consider this test case:
+**       int fd2 = open("./file2", O_RDWR|O_CREAT, 0644);
+**
+** Suppose ./file1 and ./file2 are really the same file (because
+** one is a hard or symbolic link to the other) then if you set
+** an exclusive lock on fd1, then try to get an exclusive lock
+** on fd2, it works.  I would have expected the second lock to
+** fail since there was already a lock on the file due to fd1.
+** But not so.  Since both locks came from the same process, the
+** second overrides the first, even though they were on different
+** file descriptors opened on different file names.
+**
+** Bummer.  If you ask me, this is broken.  Badly broken.  It means
+** that we cannot use POSIX locks to synchronize file access among
+** competing threads of the same process.  POSIX locks will work fine
+** to synchronize access for threads in separate processes, but not
+** threads within the same process.
+**
+** To work around the problem, SQLite has to manage file locks internally
+** on its own.  Whenever a new database is opened, we have to find the
+** specific inode of the database file (the inode is determined by the
+** st_dev and st_ino fields of the stat structure that fstat() fills in)
+** and check for locks already existing on that inode.  When locks are
+** created or removed, we have to look at our own internal record of the
+** locks to see if another thread has previously set a lock on that same
+** inode.
+**
+** The sqlite3_file structure for POSIX is no longer just an integer file
+** descriptor.  It is now a structure that holds the integer file
+** descriptor and a pointer to a structure that describes the internal
+** locks on the corresponding inode.  There is one locking structure
+** per inode, so if the same inode is opened twice, both unixFile structures
+** point to the same locking structure.  The locking structure keeps
+** a reference count (so we will know when to delete it) and a "cnt"
+** field that tells us its internal lock status.  cnt==0 means the
+** file is unlocked.  cnt==-1 means the file has an exclusive lock.
+** cnt>0 means there are cnt shared locks on the file.
+**
+** Any attempt to lock or unlock a file first checks the locking
+** structure.  The fcntl() system call is only invoked to set a 
+** POSIX lock if the internal lock structure transitions between
+** a locked and an unlocked state.
+**
+** 2004-Jan-11:
+** More recent discoveries about POSIX advisory locks.  (The more
+** I discover, the more I realize the a POSIX advisory locks are
+** an abomination.)
+**
+** If you close a file descriptor that points to a file that has locks,
+** all locks on that file that are owned by the current process are
+** released.  To work around this problem, each unixFile structure contains
+** a pointer to an openCnt structure.  There is one openCnt structure
+** per open inode, which means that multiple unixFile can point to a single
+** openCnt.  When an attempt is made to close an unixFile, if there are
+** other unixFile open on the same inode that are holding locks, the call
+** to close() the file descriptor is deferred until all of the locks clear.
+** The openCnt structure keeps a list of file descriptors that need to
+** be closed and that list is walked (and cleared) when the last lock
+** clears.
+**
+** First, under Linux threads, because each thread has a separate
+** process ID, lock operations in one thread do not override locks
+** to the same file in other threads.  Linux threads behave like
+** separate processes in this respect.  But, if you close a file
+** descriptor in linux threads, all locks are cleared, even locks
+** on other threads and even though the other threads have different
+** process IDs.  Linux threads is inconsistent in this respect.
+** (I'm beginning to think that linux threads is an abomination too.)
+** The consequence of this all is that the hash table for the lockInfo
+** structure has to include the process id as part of its key because
+** locks in different threads are treated as distinct.  But the 
+** openCnt structure should not include the process id in its
+** key because close() clears lock on all threads, not just the current
+** thread.  Were it not for this goofiness in linux threads, we could
+** combine the lockInfo and openCnt structures into a single structure.
+**
+** 2004-Jun-28:
+** On some versions of linux, threads can override each others locks.
+** On others not.  Sometimes you can change the behavior on the same
+** system by setting the LD_ASSUME_KERNEL environment variable.  The
+** POSIX standard is silent as to which behavior is correct, as far
+** as I can tell, so other versions of unix might show the same
+** inconsistency.  There is no little doubt in my mind that posix
+** advisory locks and linux threads are profoundly broken.
+**
+** To work around the inconsistencies, we have to test at runtime 
+** whether or not threads can override each others locks.  This test
+** is run once, the first time any lock is attempted.  A static 
+** variable is set to record the results of this test for future
+** use.
+*/
+
+/*
+** An instance of the following structure serves as the key used
+** to locate a particular lockInfo structure given its inode.
+**
+** If threads cannot override each others locks, then we set the
+** lockKey.tid field to the thread ID.  If threads can override
+** each others locks then tid is always set to zero.  tid is omitted
+** if we compile without threading support.
+*/
+struct lockKey {
+  dev_t dev;       /* Device number */
+  ino_t ino;       /* Inode number */
+#if SQLITE_THREADSAFE
+  pthread_t tid;   /* Thread ID or zero if threads can override each other */
+#endif
+};
+
+/*
+** An instance of the following structure is allocated for each open
+** inode on each thread with a different process ID.  (Threads have
+** different process IDs on linux, but not on most other unixes.)
+**
+** A single inode can have multiple file descriptors, so each unixFile
+** structure contains a pointer to an instance of this object and this
+** object keeps a count of the number of unixFile pointing to it.
+*/
+struct lockInfo {
+  struct lockKey key;  /* The lookup key */
+  int cnt;             /* Number of SHARED locks held */
+  int locktype;        /* One of SHARED_LOCK, RESERVED_LOCK etc. */
+  int nRef;            /* Number of pointers to this structure */
+  struct lockInfo *pNext, *pPrev;   /* List of all lockInfo objects */
+};
+
+/*
+** An instance of the following structure serves as the key used
+** to locate a particular openCnt structure given its inode.  This
+** is the same as the lockKey except that the thread ID is omitted.
+*/
+struct openKey {
+  dev_t dev;   /* Device number */
+  ino_t ino;   /* Inode number */
+};
+
+/*
+** An instance of the following structure is allocated for each open
+** inode.  This structure keeps track of the number of locks on that
+** inode.  If a close is attempted against an inode that is holding
+** locks, the close is deferred until all locks clear by adding the
+** file descriptor to be closed to the pending list.
+*/
+struct openCnt {
+  struct openKey key;   /* The lookup key */
+  int nRef;             /* Number of pointers to this structure */
+  int nLock;            /* Number of outstanding locks */
+  int nPending;         /* Number of pending close() operations */
+  int *aPending;        /* Malloced space holding fd's awaiting a close() */
+  struct openCnt *pNext, *pPrev;   /* List of all openCnt objects */
+};
+
+/*
+** List of all lockInfo and openCnt objects.  This used to be a hash
+** table.  But the number of objects is rarely more than a dozen and
+** never exceeds a few thousand.  And lookup is not on a critical
+** path oo a simple linked list will suffice.
+*/
+static struct lockInfo *lockList = 0;
+static struct openCnt *openList = 0;
+
+/*
+** The locking styles are associated with the different file locking
+** capabilities supported by different file systems.  
+**
+** POSIX locking style fully supports shared and exclusive byte-range locks 
+** AFP locking only supports exclusive byte-range locks
+** FLOCK only supports a single file-global exclusive lock
+** DOTLOCK isn't a true locking style, it refers to the use of a special
+**   file named the same as the database file with a '.lock' extension, this
+**   can be used on file systems that do not offer any reliable file locking
+** NO locking means that no locking will be attempted, this is only used for
+**   read-only file systems currently
+** UNSUPPORTED means that no locking will be attempted, this is only used for
+**   file systems that are known to be unsupported
+*/
+#define LOCKING_STYLE_POSIX        1
+#define LOCKING_STYLE_NONE         2
+#define LOCKING_STYLE_DOTFILE      3
+#define LOCKING_STYLE_FLOCK        4
+#define LOCKING_STYLE_AFP          5
+
+/*
+** Helper functions to obtain and relinquish the global mutex.
+*/
+static void enterMutex(){
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+}
+static void leaveMutex(){
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+}
+
+#if SQLITE_THREADSAFE
+/*
+** This variable records whether or not threads can override each others
+** locks.
+**
+**    0:  No.  Threads cannot override each others locks.
+**    1:  Yes.  Threads can override each others locks.
+**   -1:  We don't know yet.
+**
+** On some systems, we know at compile-time if threads can override each
+** others locks.  On those systems, the SQLITE_THREAD_OVERRIDE_LOCK macro
+** will be set appropriately.  On other systems, we have to check at
+** runtime.  On these latter systems, SQLTIE_THREAD_OVERRIDE_LOCK is
+** undefined.
+**
+** This variable normally has file scope only.  But during testing, we make
+** it a global so that the test code can change its value in order to verify
+** that the right stuff happens in either case.
+*/
+#ifndef SQLITE_THREAD_OVERRIDE_LOCK
+# define SQLITE_THREAD_OVERRIDE_LOCK -1
+#endif
+#ifdef SQLITE_TEST
+int threadsOverrideEachOthersLocks = SQLITE_THREAD_OVERRIDE_LOCK;
+#else
+static int threadsOverrideEachOthersLocks = SQLITE_THREAD_OVERRIDE_LOCK;
+#endif
+
+/*
+** This structure holds information passed into individual test
+** threads by the testThreadLockingBehavior() routine.
+*/
+struct threadTestData {
+  int fd;                /* File to be locked */
+  struct flock lock;     /* The locking operation */
+  int result;            /* Result of the locking operation */
+};
+
+#ifdef SQLITE_LOCK_TRACE
+/*
+** Print out information about all locking operations.
+**
+** This routine is used for troubleshooting locks on multithreaded
+** platforms.  Enable by compiling with the -DSQLITE_LOCK_TRACE
+** command-line option on the compiler.  This code is normally
+** turned off.
+*/
+static int lockTrace(int fd, int op, struct flock *p){
+  char *zOpName, *zType;
+  int s;
+  int savedErrno;
+  if( op==F_GETLK ){
+    zOpName = "GETLK";
+  }else if( op==F_SETLK ){
+    zOpName = "SETLK";
+  }else{
+    s = fcntl(fd, op, p);
+    sqlite3DebugPrintf("fcntl unknown %d %d %d\n", fd, op, s);
+    return s;
+  }
+  if( p->l_type==F_RDLCK ){
+    zType = "RDLCK";
+  }else if( p->l_type==F_WRLCK ){
+    zType = "WRLCK";
+  }else if( p->l_type==F_UNLCK ){
+    zType = "UNLCK";
+  }else{
+    assert( 0 );
+  }
+  assert( p->l_whence==SEEK_SET );
+  s = fcntl(fd, op, p);
+  savedErrno = errno;
+  sqlite3DebugPrintf("fcntl %d %d %s %s %d %d %d %d\n",
+     threadid, fd, zOpName, zType, (int)p->l_start, (int)p->l_len,
+     (int)p->l_pid, s);
+  if( s==(-1) && op==F_SETLK && (p->l_type==F_RDLCK || p->l_type==F_WRLCK) ){
+    struct flock l2;
+    l2 = *p;
+    fcntl(fd, F_GETLK, &l2);
+    if( l2.l_type==F_RDLCK ){
+      zType = "RDLCK";
+    }else if( l2.l_type==F_WRLCK ){
+      zType = "WRLCK";
+    }else if( l2.l_type==F_UNLCK ){
+      zType = "UNLCK";
+    }else{
+      assert( 0 );
+    }
+    sqlite3DebugPrintf("fcntl-failure-reason: %s %d %d %d\n",
+       zType, (int)l2.l_start, (int)l2.l_len, (int)l2.l_pid);
+  }
+  errno = savedErrno;
+  return s;
+}
+#define fcntl lockTrace
+#endif /* SQLITE_LOCK_TRACE */
+
+/*
+** The testThreadLockingBehavior() routine launches two separate
+** threads on this routine.  This routine attempts to lock a file
+** descriptor then returns.  The success or failure of that attempt
+** allows the testThreadLockingBehavior() procedure to determine
+** whether or not threads can override each others locks.
+*/
+static void *threadLockingTest(void *pArg){
+  struct threadTestData *pData = (struct threadTestData*)pArg;
+  pData->result = fcntl(pData->fd, F_SETLK, &pData->lock);
+  return pArg;
+}
+
+/*
+** This procedure attempts to determine whether or not threads
+** can override each others locks then sets the 
+** threadsOverrideEachOthersLocks variable appropriately.
+*/
+static void testThreadLockingBehavior(int fd_orig){
+  int fd;
+  struct threadTestData d[2];
+  pthread_t t[2];
+
+  fd = dup(fd_orig);
+  if( fd<0 ) return;
+  memset(d, 0, sizeof(d));
+  d[0].fd = fd;
+  d[0].lock.l_type = F_RDLCK;
+  d[0].lock.l_len = 1;
+  d[0].lock.l_start = 0;
+  d[0].lock.l_whence = SEEK_SET;
+  d[1] = d[0];
+  d[1].lock.l_type = F_WRLCK;
+  pthread_create(&t[0], 0, threadLockingTest, &d[0]);
+  pthread_create(&t[1], 0, threadLockingTest, &d[1]);
+  pthread_join(t[0], 0);
+  pthread_join(t[1], 0);
+  close(fd);
+  threadsOverrideEachOthersLocks =  d[0].result==0 && d[1].result==0;
+}
+#endif /* SQLITE_THREADSAFE */
+
+/*
+** Release a lockInfo structure previously allocated by findLockInfo().
+*/
+static void releaseLockInfo(struct lockInfo *pLock){
+  if( pLock ){
+    pLock->nRef--;
+    if( pLock->nRef==0 ){
+      if( pLock->pPrev ){
+        assert( pLock->pPrev->pNext==pLock );
+        pLock->pPrev->pNext = pLock->pNext;
+      }else{
+        assert( lockList==pLock );
+        lockList = pLock->pNext;
+      }
+      if( pLock->pNext ){
+        assert( pLock->pNext->pPrev==pLock );
+        pLock->pNext->pPrev = pLock->pPrev;
+      }
+      sqlite3_free(pLock);
+    }
+  }
+}
+
+/*
+** Release a openCnt structure previously allocated by findLockInfo().
+*/
+static void releaseOpenCnt(struct openCnt *pOpen){
+  if( pOpen ){
+    pOpen->nRef--;
+    if( pOpen->nRef==0 ){
+      if( pOpen->pPrev ){
+        assert( pOpen->pPrev->pNext==pOpen );
+        pOpen->pPrev->pNext = pOpen->pNext;
+      }else{
+        assert( openList==pOpen );
+        openList = pOpen->pNext;
+      }
+      if( pOpen->pNext ){
+        assert( pOpen->pNext->pPrev==pOpen );
+        pOpen->pNext->pPrev = pOpen->pPrev;
+      }
+      sqlite3_free(pOpen->aPending);
+      sqlite3_free(pOpen);
+    }
+  }
+}
+
+#ifdef SQLITE_ENABLE_LOCKING_STYLE
+/*
+** Tests a byte-range locking query to see if byte range locks are 
+** supported, if not we fall back to dotlockLockingStyle.
+*/
+static int testLockingStyle(int fd){
+  struct flock lockInfo;
+
+  /* Test byte-range lock using fcntl(). If the call succeeds, 
+  ** assume that the file-system supports POSIX style locks. 
+  */
+  lockInfo.l_len = 1;
+  lockInfo.l_start = 0;
+  lockInfo.l_whence = SEEK_SET;
+  lockInfo.l_type = F_RDLCK;
+  if( fcntl(fd, F_GETLK, &lockInfo)!=-1 ) {
+    return LOCKING_STYLE_POSIX;
+  }
+  
+  /* Testing for flock() can give false positives.  So if if the above 
+  ** test fails, then we fall back to using dot-file style locking.
+  */  
+  return LOCKING_STYLE_DOTFILE;
+}
+#endif
+
+/* 
+** If SQLITE_ENABLE_LOCKING_STYLE is defined, this function Examines the 
+** f_fstypename entry in the statfs structure as returned by stat() for 
+** the file system hosting the database file and selects  the appropriate
+** locking style based on its value.  These values and assignments are 
+** based on Darwin/OSX behavior and have not been thoroughly tested on 
+** other systems.
+**
+** If SQLITE_ENABLE_LOCKING_STYLE is not defined, this function always
+** returns LOCKING_STYLE_POSIX.
+*/
+static int detectLockingStyle(
+  sqlite3_vfs *pVfs,
+  const char *filePath, 
+  int fd
+){
+#ifdef SQLITE_ENABLE_LOCKING_STYLE
+  struct Mapping {
+    const char *zFilesystem;
+    int eLockingStyle;
+  } aMap[] = {
+    { "hfs",    LOCKING_STYLE_POSIX },
+    { "ufs",    LOCKING_STYLE_POSIX },
+    { "afpfs",  LOCKING_STYLE_AFP },
+    { "smbfs",  LOCKING_STYLE_FLOCK },
+    { "msdos",  LOCKING_STYLE_DOTFILE },
+    { "webdav", LOCKING_STYLE_NONE },
+    { 0, 0 }
+  };
+  int i;
+  struct statfs fsInfo;
+
+  if( !filePath ){
+    return LOCKING_STYLE_NONE;
+  }
+  if( pVfs->pAppData ){
+    return (int)pVfs->pAppData;
+  }
+
+  if( statfs(filePath, &fsInfo) != -1 ){
+    if( fsInfo.f_flags & MNT_RDONLY ){
+      return LOCKING_STYLE_NONE;
+    }
+    for(i=0; aMap[i].zFilesystem; i++){
+      if( strcmp(fsInfo.f_fstypename, aMap[i].zFilesystem)==0 ){
+        return aMap[i].eLockingStyle;
+      }
+    }
+  }
+
+  /* Default case. Handles, amongst others, "nfs". */
+  return testLockingStyle(fd);  
+#endif
+  return LOCKING_STYLE_POSIX;
+}
+
+/*
+** Given a file descriptor, locate lockInfo and openCnt structures that
+** describes that file descriptor.  Create new ones if necessary.  The
+** return values might be uninitialized if an error occurs.
+**
+** Return an appropriate error code.
+*/
+static int findLockInfo(
+  int fd,                      /* The file descriptor used in the key */
+  struct lockInfo **ppLock,    /* Return the lockInfo structure here */
+  struct openCnt **ppOpen      /* Return the openCnt structure here */
+){
+  int rc;
+  struct lockKey key1;
+  struct openKey key2;
+  struct stat statbuf;
+  struct lockInfo *pLock;
+  struct openCnt *pOpen;
+  rc = fstat(fd, &statbuf);
+  if( rc!=0 ){
+#ifdef EOVERFLOW
+    if( errno==EOVERFLOW ) return SQLITE_NOLFS;
+#endif
+    return SQLITE_IOERR;
+  }
+
+  /* On OS X on an msdos filesystem, the inode number is reported
+  ** incorrectly for zero-size files.  See ticket #3260.  To work
+  ** around this problem (we consider it a bug in OS X, not SQLite)
+  ** we always increase the file size to 1 by writing a single byte
+  ** prior to accessing the inode number.  The one byte written is
+  ** an ASCII 'S' character which also happens to be the first byte
+  ** in the header of every SQLite database.  In this way, if there
+  ** is a race condition such that another thread has already populated
+  ** the first page of the database, no damage is done.
+  */
+  if( statbuf.st_size==0 ){
+    write(fd, "S", 1);
+    rc = fstat(fd, &statbuf);
+    if( rc!=0 ){
+      return SQLITE_IOERR;
+    }
+  }
+
+  memset(&key1, 0, sizeof(key1));
+  key1.dev = statbuf.st_dev;
+  key1.ino = statbuf.st_ino;
+#if SQLITE_THREADSAFE
+  if( threadsOverrideEachOthersLocks<0 ){
+    testThreadLockingBehavior(fd);
+  }
+  key1.tid = threadsOverrideEachOthersLocks ? 0 : pthread_self();
+#endif
+  memset(&key2, 0, sizeof(key2));
+  key2.dev = statbuf.st_dev;
+  key2.ino = statbuf.st_ino;
+  pLock = lockList;
+  while( pLock && memcmp(&key1, &pLock->key, sizeof(key1)) ){
+    pLock = pLock->pNext;
+  }
+  if( pLock==0 ){
+    pLock = sqlite3_malloc( sizeof(*pLock) );
+    if( pLock==0 ){
+      rc = SQLITE_NOMEM;
+      goto exit_findlockinfo;
+    }
+    pLock->key = key1;
+    pLock->nRef = 1;
+    pLock->cnt = 0;
+    pLock->locktype = 0;
+    pLock->pNext = lockList;
+    pLock->pPrev = 0;
+    if( lockList ) lockList->pPrev = pLock;
+    lockList = pLock;
+  }else{
+    pLock->nRef++;
+  }
+  *ppLock = pLock;
+  if( ppOpen!=0 ){
+    pOpen = openList;
+    while( pOpen && memcmp(&key2, &pOpen->key, sizeof(key2)) ){
+      pOpen = pOpen->pNext;
+    }
+    if( pOpen==0 ){
+      pOpen = sqlite3_malloc( sizeof(*pOpen) );
+      if( pOpen==0 ){
+        releaseLockInfo(pLock);
+        rc = SQLITE_NOMEM;
+        goto exit_findlockinfo;
+      }
+      pOpen->key = key2;
+      pOpen->nRef = 1;
+      pOpen->nLock = 0;
+      pOpen->nPending = 0;
+      pOpen->aPending = 0;
+      pOpen->pNext = openList;
+      pOpen->pPrev = 0;
+      if( openList ) openList->pPrev = pOpen;
+      openList = pOpen;
+    }else{
+      pOpen->nRef++;
+    }
+    *ppOpen = pOpen;
+  }
+
+exit_findlockinfo:
+  return rc;
+}
+
+#ifdef SQLITE_DEBUG
+/*
+** Helper function for printing out trace information from debugging
+** binaries. This returns the string represetation of the supplied
+** integer lock-type.
+*/
+static const char *locktypeName(int locktype){
+  switch( locktype ){
+  case NO_LOCK: return "NONE";
+  case SHARED_LOCK: return "SHARED";
+  case RESERVED_LOCK: return "RESERVED";
+  case PENDING_LOCK: return "PENDING";
+  case EXCLUSIVE_LOCK: return "EXCLUSIVE";
+  }
+  return "ERROR";
+}
+#endif
+
+/*
+** If we are currently in a different thread than the thread that the
+** unixFile argument belongs to, then transfer ownership of the unixFile
+** over to the current thread.
+**
+** A unixFile is only owned by a thread on systems where one thread is
+** unable to override locks created by a different thread.  RedHat9 is
+** an example of such a system.
+**
+** Ownership transfer is only allowed if the unixFile is currently unlocked.
+** If the unixFile is locked and an ownership is wrong, then return
+** SQLITE_MISUSE.  SQLITE_OK is returned if everything works.
+*/
+#if SQLITE_THREADSAFE
+static int transferOwnership(unixFile *pFile){
+  int rc;
+  pthread_t hSelf;
+  if( threadsOverrideEachOthersLocks ){
+    /* Ownership transfers not needed on this system */
+    return SQLITE_OK;
+  }
+  hSelf = pthread_self();
+  if( pthread_equal(pFile->tid, hSelf) ){
+    /* We are still in the same thread */
+    OSTRACE1("No-transfer, same thread\n");
+    return SQLITE_OK;
+  }
+  if( pFile->locktype!=NO_LOCK ){
+    /* We cannot change ownership while we are holding a lock! */
+    return SQLITE_MISUSE;
+  }
+  OSTRACE4("Transfer ownership of %d from %d to %d\n",
+            pFile->h, pFile->tid, hSelf);
+  pFile->tid = hSelf;
+  if (pFile->pLock != NULL) {
+    releaseLockInfo(pFile->pLock);
+    rc = findLockInfo(pFile->h, &pFile->pLock, 0);
+    OSTRACE5("LOCK    %d is now %s(%s,%d)\n", pFile->h,
+           locktypeName(pFile->locktype),
+           locktypeName(pFile->pLock->locktype), pFile->pLock->cnt);
+    return rc;
+  } else {
+    return SQLITE_OK;
+  }
+}
+#else
+  /* On single-threaded builds, ownership transfer is a no-op */
+# define transferOwnership(X) SQLITE_OK
+#endif
+
+/*
+** Seek to the offset passed as the second argument, then read cnt 
+** bytes into pBuf. Return the number of bytes actually read.
+**
+** NB:  If you define USE_PREAD or USE_PREAD64, then it might also
+** be necessary to define _XOPEN_SOURCE to be 500.  This varies from
+** one system to another.  Since SQLite does not define USE_PREAD
+** any any form by default, we will not attempt to define _XOPEN_SOURCE.
+** See tickets #2741 and #2681.
+*/
+static int seekAndRead(unixFile *id, sqlite3_int64 offset, void *pBuf, int cnt){
+  int got;
+  i64 newOffset;
+  TIMER_START;
+#if defined(USE_PREAD)
+  got = pread(id->h, pBuf, cnt, offset);
+  SimulateIOError( got = -1 );
+#elif defined(USE_PREAD64)
+  got = pread64(id->h, pBuf, cnt, offset);
+  SimulateIOError( got = -1 );
+#else
+  newOffset = lseek(id->h, offset, SEEK_SET);
+  SimulateIOError( newOffset-- );
+  if( newOffset!=offset ){
+    return -1;
+  }
+  got = read(id->h, pBuf, cnt);
+#endif
+  TIMER_END;
+  OSTRACE5("READ    %-3d %5d %7lld %llu\n", id->h, got, offset, TIMER_ELAPSED);
+  return got;
+}
+
+/*
+** Read data from a file into a buffer.  Return SQLITE_OK if all
+** bytes were read successfully and SQLITE_IOERR if anything goes
+** wrong.
+*/
+static int unixRead(
+  sqlite3_file *id, 
+  void *pBuf, 
+  int amt,
+  sqlite3_int64 offset
+){
+  int got;
+  assert( id );
+  got = seekAndRead((unixFile*)id, offset, pBuf, amt);
+  if( got==amt ){
+    return SQLITE_OK;
+  }else if( got<0 ){
+    return SQLITE_IOERR_READ;
+  }else{
+    memset(&((char*)pBuf)[got], 0, amt-got);
+    return SQLITE_IOERR_SHORT_READ;
+  }
+}
+
+/*
+** Seek to the offset in id->offset then read cnt bytes into pBuf.
+** Return the number of bytes actually read.  Update the offset.
+*/
+static int seekAndWrite(unixFile *id, i64 offset, const void *pBuf, int cnt){
+  int got;
+  i64 newOffset;
+  TIMER_START;
+#if defined(USE_PREAD)
+  got = pwrite(id->h, pBuf, cnt, offset);
+#elif defined(USE_PREAD64)
+  got = pwrite64(id->h, pBuf, cnt, offset);
+#else
+  newOffset = lseek(id->h, offset, SEEK_SET);
+  if( newOffset!=offset ){
+    return -1;
+  }
+  got = write(id->h, pBuf, cnt);
+#endif
+  TIMER_END;
+  OSTRACE5("WRITE   %-3d %5d %7lld %llu\n", id->h, got, offset, TIMER_ELAPSED);
+  return got;
+}
+
+
+/*
+** Write data from a buffer into a file.  Return SQLITE_OK on success
+** or some other error code on failure.
+*/
+static int unixWrite(
+  sqlite3_file *id, 
+  const void *pBuf, 
+  int amt,
+  sqlite3_int64 offset 
+){
+  int wrote = 0;
+  assert( id );
+  assert( amt>0 );
+  while( amt>0 && (wrote = seekAndWrite((unixFile*)id, offset, pBuf, amt))>0 ){
+    amt -= wrote;
+    offset += wrote;
+    pBuf = &((char*)pBuf)[wrote];
+  }
+  SimulateIOError(( wrote=(-1), amt=1 ));
+  SimulateDiskfullError(( wrote=0, amt=1 ));
+  if( amt>0 ){
+    if( wrote<0 ){
+      return SQLITE_IOERR_WRITE;
+    }else{
+      return SQLITE_FULL;
+    }
+  }
+  return SQLITE_OK;
+}
+
+#ifdef SQLITE_TEST
+/*
+** Count the number of fullsyncs and normal syncs.  This is used to test
+** that syncs and fullsyncs are occuring at the right times.
+*/
+int sqlite3_sync_count = 0;
+int sqlite3_fullsync_count = 0;
+#endif
+
+/*
+** Use the fdatasync() API only if the HAVE_FDATASYNC macro is defined.
+** Otherwise use fsync() in its place.
+*/
+#ifndef HAVE_FDATASYNC
+# define fdatasync fsync
+#endif
+
+/*
+** Define HAVE_FULLFSYNC to 0 or 1 depending on whether or not
+** the F_FULLFSYNC macro is defined.  F_FULLFSYNC is currently
+** only available on Mac OS X.  But that could change.
+*/
+#ifdef F_FULLFSYNC
+# define HAVE_FULLFSYNC 1
+#else
+# define HAVE_FULLFSYNC 0
+#endif
+
+
+/*
+** The fsync() system call does not work as advertised on many
+** unix systems.  The following procedure is an attempt to make
+** it work better.
+**
+** The SQLITE_NO_SYNC macro disables all fsync()s.  This is useful
+** for testing when we want to run through the test suite quickly.
+** You are strongly advised *not* to deploy with SQLITE_NO_SYNC
+** enabled, however, since with SQLITE_NO_SYNC enabled, an OS crash
+** or power failure will likely corrupt the database file.
+*/
+static int full_fsync(int fd, int fullSync, int dataOnly){
+  int rc;
+
+  /* Record the number of times that we do a normal fsync() and 
+  ** FULLSYNC.  This is used during testing to verify that this procedure
+  ** gets called with the correct arguments.
+  */
+#ifdef SQLITE_TEST
+  if( fullSync ) sqlite3_fullsync_count++;
+  sqlite3_sync_count++;
+#endif
+
+  /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
+  ** no-op
+  */
+#ifdef SQLITE_NO_SYNC
+  rc = SQLITE_OK;
+#else
+
+#if HAVE_FULLFSYNC
+  if( fullSync ){
+    rc = fcntl(fd, F_FULLFSYNC, 0);
+  }else{
+    rc = 1;
+  }
+  /* If the FULLFSYNC failed, fall back to attempting an fsync().
+   * It shouldn't be possible for fullfsync to fail on the local 
+   * file system (on OSX), so failure indicates that FULLFSYNC
+   * isn't supported for this file system. So, attempt an fsync 
+   * and (for now) ignore the overhead of a superfluous fcntl call.  
+   * It'd be better to detect fullfsync support once and avoid 
+   * the fcntl call every time sync is called.
+   */
+  if( rc ) rc = fsync(fd);
+
+#else 
+  if( dataOnly ){
+    rc = fdatasync(fd);
+  }else{
+    rc = fsync(fd);
+  }
+#endif /* HAVE_FULLFSYNC */
+#endif /* defined(SQLITE_NO_SYNC) */
+
+  return rc;
+}
+
+/*
+** Make sure all writes to a particular file are committed to disk.
+**
+** If dataOnly==0 then both the file itself and its metadata (file
+** size, access time, etc) are synced.  If dataOnly!=0 then only the
+** file data is synced.
+**
+** Under Unix, also make sure that the directory entry for the file
+** has been created by fsync-ing the directory that contains the file.
+** If we do not do this and we encounter a power failure, the directory
+** entry for the journal might not exist after we reboot.  The next
+** SQLite to access the file will not know that the journal exists (because
+** the directory entry for the journal was never created) and the transaction
+** will not roll back - possibly leading to database corruption.
+*/
+static int unixSync(sqlite3_file *id, int flags){
+  int rc;
+  unixFile *pFile = (unixFile*)id;
+
+  int isDataOnly = (flags&SQLITE_SYNC_DATAONLY);
+  int isFullsync = (flags&0x0F)==SQLITE_SYNC_FULL;
+
+  /* Check that one of SQLITE_SYNC_NORMAL or FULL was passed */
+  assert((flags&0x0F)==SQLITE_SYNC_NORMAL
+      || (flags&0x0F)==SQLITE_SYNC_FULL
+  );
+
+  assert( pFile );
+  OSTRACE2("SYNC    %-3d\n", pFile->h);
+  rc = full_fsync(pFile->h, isFullsync, isDataOnly);
+  SimulateIOError( rc=1 );
+  if( rc ){
+    return SQLITE_IOERR_FSYNC;
+  }
+  if( pFile->dirfd>=0 ){
+    OSTRACE4("DIRSYNC %-3d (have_fullfsync=%d fullsync=%d)\n", pFile->dirfd,
+            HAVE_FULLFSYNC, isFullsync);
+#ifndef SQLITE_DISABLE_DIRSYNC
+    /* The directory sync is only attempted if full_fsync is
+    ** turned off or unavailable.  If a full_fsync occurred above,
+    ** then the directory sync is superfluous.
+    */
+    if( (!HAVE_FULLFSYNC || !isFullsync) && full_fsync(pFile->dirfd,0,0) ){
+       /*
+       ** We have received multiple reports of fsync() returning
+       ** errors when applied to directories on certain file systems.
+       ** A failed directory sync is not a big deal.  So it seems
+       ** better to ignore the error.  Ticket #1657
+       */
+       /* return SQLITE_IOERR; */
+    }
+#endif
+    close(pFile->dirfd);  /* Only need to sync once, so close the directory */
+    pFile->dirfd = -1;    /* when we are done. */
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Truncate an open file to a specified size
+*/
+static int unixTruncate(sqlite3_file *id, i64 nByte){
+  int rc;
+  assert( id );
+  SimulateIOError( return SQLITE_IOERR_TRUNCATE );
+  rc = ftruncate(((unixFile*)id)->h, (off_t)nByte);
+  if( rc ){
+    return SQLITE_IOERR_TRUNCATE;
+  }else{
+    return SQLITE_OK;
+  }
+}
+
+/*
+** Determine the current size of a file in bytes
+*/
+static int unixFileSize(sqlite3_file *id, i64 *pSize){
+  int rc;
+  struct stat buf;
+  assert( id );
+  rc = fstat(((unixFile*)id)->h, &buf);
+  SimulateIOError( rc=1 );
+  if( rc!=0 ){
+    return SQLITE_IOERR_FSTAT;
+  }
+  *pSize = buf.st_size;
+
+  /* When opening a zero-size database, the findLockInfo() procedure
+  ** writes a single byte into that file in order to work around a bug
+  ** in the OS-X msdos filesystem.  In order to avoid problems with upper
+  ** layers, we need to report this file size as zero even though it is
+  ** really 1.   Ticket #3260.
+  */
+  if( *pSize==1 ) *pSize = 0;
+
+
+  return SQLITE_OK;
+}
+
+/*
+** This routine checks if there is a RESERVED lock held on the specified
+** file by this or any other process. If such a lock is held, return
+** non-zero.  If the file is unlocked or holds only SHARED locks, then
+** return zero.
+*/
+static int unixCheckReservedLock(sqlite3_file *id, int *pResOut){
+  int r = 0;
+  unixFile *pFile = (unixFile*)id;
+
+  SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
+
+  assert( pFile );
+  enterMutex(); /* Because pFile->pLock is shared across threads */
+
+  /* Check if a thread in this process holds such a lock */
+  if( pFile->pLock->locktype>SHARED_LOCK ){
+    r = 1;
+  }
+
+  /* Otherwise see if some other process holds it.
+  */
+  if( !r ){
+    struct flock lock;
+    lock.l_whence = SEEK_SET;
+    lock.l_start = RESERVED_BYTE;
+    lock.l_len = 1;
+    lock.l_type = F_WRLCK;
+    fcntl(pFile->h, F_GETLK, &lock);
+    if( lock.l_type!=F_UNLCK ){
+      r = 1;
+    }
+  }
+  
+  leaveMutex();
+  OSTRACE3("TEST WR-LOCK %d %d\n", pFile->h, r);
+
+  *pResOut = r;
+  return SQLITE_OK;
+}
+
+/*
+** Lock the file with the lock specified by parameter locktype - one
+** of the following:
+**
+**     (1) SHARED_LOCK
+**     (2) RESERVED_LOCK
+**     (3) PENDING_LOCK
+**     (4) EXCLUSIVE_LOCK
+**
+** Sometimes when requesting one lock state, additional lock states
+** are inserted in between.  The locking might fail on one of the later
+** transitions leaving the lock state different from what it started but
+** still short of its goal.  The following chart shows the allowed
+** transitions and the inserted intermediate states:
+**
+**    UNLOCKED -> SHARED
+**    SHARED -> RESERVED
+**    SHARED -> (PENDING) -> EXCLUSIVE
+**    RESERVED -> (PENDING) -> EXCLUSIVE
+**    PENDING -> EXCLUSIVE
+**
+** This routine will only increase a lock.  Use the sqlite3OsUnlock()
+** routine to lower a locking level.
+*/
+static int unixLock(sqlite3_file *id, int locktype){
+  /* The following describes the implementation of the various locks and
+  ** lock transitions in terms of the POSIX advisory shared and exclusive
+  ** lock primitives (called read-locks and write-locks below, to avoid
+  ** confusion with SQLite lock names). The algorithms are complicated
+  ** slightly in order to be compatible with windows systems simultaneously
+  ** accessing the same database file, in case that is ever required.
+  **
+  ** Symbols defined in os.h indentify the 'pending byte' and the 'reserved
+  ** byte', each single bytes at well known offsets, and the 'shared byte
+  ** range', a range of 510 bytes at a well known offset.
+  **
+  ** To obtain a SHARED lock, a read-lock is obtained on the 'pending
+  ** byte'.  If this is successful, a random byte from the 'shared byte
+  ** range' is read-locked and the lock on the 'pending byte' released.
+  **
+  ** A process may only obtain a RESERVED lock after it has a SHARED lock.
+  ** A RESERVED lock is implemented by grabbing a write-lock on the
+  ** 'reserved byte'. 
+  **
+  ** A process may only obtain a PENDING lock after it has obtained a
+  ** SHARED lock. A PENDING lock is implemented by obtaining a write-lock
+  ** on the 'pending byte'. This ensures that no new SHARED locks can be
+  ** obtained, but existing SHARED locks are allowed to persist. A process
+  ** does not have to obtain a RESERVED lock on the way to a PENDING lock.
+  ** This property is used by the algorithm for rolling back a journal file
+  ** after a crash.
+  **
+  ** An EXCLUSIVE lock, obtained after a PENDING lock is held, is
+  ** implemented by obtaining a write-lock on the entire 'shared byte
+  ** range'. Since all other locks require a read-lock on one of the bytes
+  ** within this range, this ensures that no other locks are held on the
+  ** database. 
+  **
+  ** The reason a single byte cannot be used instead of the 'shared byte
+  ** range' is that some versions of windows do not support read-locks. By
+  ** locking a random byte from a range, concurrent SHARED locks may exist
+  ** even if the locking primitive used is always a write-lock.
+  */
+  int rc = SQLITE_OK;
+  unixFile *pFile = (unixFile*)id;
+  struct lockInfo *pLock = pFile->pLock;
+  struct flock lock;
+  int s;
+
+  assert( pFile );
+  OSTRACE7("LOCK    %d %s was %s(%s,%d) pid=%d\n", pFile->h,
+      locktypeName(locktype), locktypeName(pFile->locktype),
+      locktypeName(pLock->locktype), pLock->cnt , getpid());
+
+  /* If there is already a lock of this type or more restrictive on the
+  ** unixFile, do nothing. Don't use the end_lock: exit path, as
+  ** enterMutex() hasn't been called yet.
+  */
+  if( pFile->locktype>=locktype ){
+    OSTRACE3("LOCK    %d %s ok (already held)\n", pFile->h,
+            locktypeName(locktype));
+    return SQLITE_OK;
+  }
+
+  /* Make sure the locking sequence is correct
+  */
+  assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
+  assert( locktype!=PENDING_LOCK );
+  assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );
+
+  /* This mutex is needed because pFile->pLock is shared across threads
+  */
+  enterMutex();
+
+  /* Make sure the current thread owns the pFile.
+  */
+  rc = transferOwnership(pFile);
+  if( rc!=SQLITE_OK ){
+    leaveMutex();
+    return rc;
+  }
+  pLock = pFile->pLock;
+
+  /* If some thread using this PID has a lock via a different unixFile*
+  ** handle that precludes the requested lock, return BUSY.
+  */
+  if( (pFile->locktype!=pLock->locktype && 
+          (pLock->locktype>=PENDING_LOCK || locktype>SHARED_LOCK))
+  ){
+    rc = SQLITE_BUSY;
+    goto end_lock;
+  }
+
+  /* If a SHARED lock is requested, and some thread using this PID already
+  ** has a SHARED or RESERVED lock, then increment reference counts and
+  ** return SQLITE_OK.
+  */
+  if( locktype==SHARED_LOCK && 
+      (pLock->locktype==SHARED_LOCK || pLock->locktype==RESERVED_LOCK) ){
+    assert( locktype==SHARED_LOCK );
+    assert( pFile->locktype==0 );
+    assert( pLock->cnt>0 );
+    pFile->locktype = SHARED_LOCK;
+    pLock->cnt++;
+    pFile->pOpen->nLock++;
+    goto end_lock;
+  }
+
+  lock.l_len = 1L;
+
+  lock.l_whence = SEEK_SET;
+
+  /* A PENDING lock is needed before acquiring a SHARED lock and before
+  ** acquiring an EXCLUSIVE lock.  For the SHARED lock, the PENDING will
+  ** be released.
+  */
+  if( locktype==SHARED_LOCK 
+      || (locktype==EXCLUSIVE_LOCK && pFile->locktype<PENDING_LOCK)
+  ){
+    lock.l_type = (locktype==SHARED_LOCK?F_RDLCK:F_WRLCK);
+    lock.l_start = PENDING_BYTE;
+    s = fcntl(pFile->h, F_SETLK, &lock);
+    if( s==(-1) ){
+      rc = (errno==EINVAL) ? SQLITE_NOLFS : SQLITE_BUSY;
+      goto end_lock;
+    }
+  }
+
+
+  /* If control gets to this point, then actually go ahead and make
+  ** operating system calls for the specified lock.
+  */
+  if( locktype==SHARED_LOCK ){
+    assert( pLock->cnt==0 );
+    assert( pLock->locktype==0 );
+
+    /* Now get the read-lock */
+    lock.l_start = SHARED_FIRST;
+    lock.l_len = SHARED_SIZE;
+    s = fcntl(pFile->h, F_SETLK, &lock);
+
+    /* Drop the temporary PENDING lock */
+    lock.l_start = PENDING_BYTE;
+    lock.l_len = 1L;
+    lock.l_type = F_UNLCK;
+    if( fcntl(pFile->h, F_SETLK, &lock)!=0 ){
+      rc = SQLITE_IOERR_UNLOCK;  /* This should never happen */
+      goto end_lock;
+    }
+    if( s==(-1) ){
+      rc = (errno==EINVAL) ? SQLITE_NOLFS : SQLITE_BUSY;
+    }else{
+      pFile->locktype = SHARED_LOCK;
+      pFile->pOpen->nLock++;
+      pLock->cnt = 1;
+    }
+  }else if( locktype==EXCLUSIVE_LOCK && pLock->cnt>1 ){
+    /* We are trying for an exclusive lock but another thread in this
+    ** same process is still holding a shared lock. */
+    rc = SQLITE_BUSY;
+  }else{
+    /* The request was for a RESERVED or EXCLUSIVE lock.  It is
+    ** assumed that there is a SHARED or greater lock on the file
+    ** already.
+    */
+    assert( 0!=pFile->locktype );
+    lock.l_type = F_WRLCK;
+    switch( locktype ){
+      case RESERVED_LOCK:
+        lock.l_start = RESERVED_BYTE;
+        break;
+      case EXCLUSIVE_LOCK:
+        lock.l_start = SHARED_FIRST;
+        lock.l_len = SHARED_SIZE;
+        break;
+      default:
+        assert(0);
+    }
+    s = fcntl(pFile->h, F_SETLK, &lock);
+    if( s==(-1) ){
+      rc = (errno==EINVAL) ? SQLITE_NOLFS : SQLITE_BUSY;
+    }
+  }
+  
+  if( rc==SQLITE_OK ){
+    pFile->locktype = locktype;
+    pLock->locktype = locktype;
+  }else if( locktype==EXCLUSIVE_LOCK ){
+    pFile->locktype = PENDING_LOCK;
+    pLock->locktype = PENDING_LOCK;
+  }
+
+end_lock:
+  leaveMutex();
+  OSTRACE4("LOCK    %d %s %s\n", pFile->h, locktypeName(locktype), 
+      rc==SQLITE_OK ? "ok" : "failed");
+  return rc;
+}
+
+/*
+** Lower the locking level on file descriptor pFile to locktype.  locktype
+** must be either NO_LOCK or SHARED_LOCK.
+**
+** If the locking level of the file descriptor is already at or below
+** the requested locking level, this routine is a no-op.
+*/
+static int unixUnlock(sqlite3_file *id, int locktype){
+  struct lockInfo *pLock;
+  struct flock lock;
+  int rc = SQLITE_OK;
+  unixFile *pFile = (unixFile*)id;
+  int h;
+
+  assert( pFile );
+  OSTRACE7("UNLOCK  %d %d was %d(%d,%d) pid=%d\n", pFile->h, locktype,
+      pFile->locktype, pFile->pLock->locktype, pFile->pLock->cnt, getpid());
+
+  assert( locktype<=SHARED_LOCK );
+  if( pFile->locktype<=locktype ){
+    return SQLITE_OK;
+  }
+  if( CHECK_THREADID(pFile) ){
+    return SQLITE_MISUSE;
+  }
+  enterMutex();
+  h = pFile->h;
+  pLock = pFile->pLock;
+  assert( pLock->cnt!=0 );
+  if( pFile->locktype>SHARED_LOCK ){
+    assert( pLock->locktype==pFile->locktype );
+    SimulateIOErrorBenign(1);
+    SimulateIOError( h=(-1) )
+    SimulateIOErrorBenign(0);
+    if( locktype==SHARED_LOCK ){
+      lock.l_type = F_RDLCK;
+      lock.l_whence = SEEK_SET;
+      lock.l_start = SHARED_FIRST;
+      lock.l_len = SHARED_SIZE;
+      if( fcntl(h, F_SETLK, &lock)==(-1) ){
+        rc = SQLITE_IOERR_RDLOCK;
+      }
+    }
+    lock.l_type = F_UNLCK;
+    lock.l_whence = SEEK_SET;
+    lock.l_start = PENDING_BYTE;
+    lock.l_len = 2L;  assert( PENDING_BYTE+1==RESERVED_BYTE );
+    if( fcntl(h, F_SETLK, &lock)!=(-1) ){
+      pLock->locktype = SHARED_LOCK;
+    }else{
+      rc = SQLITE_IOERR_UNLOCK;
+    }
+  }
+  if( locktype==NO_LOCK ){
+    struct openCnt *pOpen;
+
+    /* Decrement the shared lock counter.  Release the lock using an
+    ** OS call only when all threads in this same process have released
+    ** the lock.
+    */
+    pLock->cnt--;
+    if( pLock->cnt==0 ){
+      lock.l_type = F_UNLCK;
+      lock.l_whence = SEEK_SET;
+      lock.l_start = lock.l_len = 0L;
+      SimulateIOErrorBenign(1);
+      SimulateIOError( h=(-1) )
+      SimulateIOErrorBenign(0);
+      if( fcntl(h, F_SETLK, &lock)!=(-1) ){
+        pLock->locktype = NO_LOCK;
+      }else{
+        rc = SQLITE_IOERR_UNLOCK;
+        pLock->cnt = 1;
+      }
+    }
+
+    /* Decrement the count of locks against this same file.  When the
+    ** count reaches zero, close any other file descriptors whose close
+    ** was deferred because of outstanding locks.
+    */
+    if( rc==SQLITE_OK ){
+      pOpen = pFile->pOpen;
+      pOpen->nLock--;
+      assert( pOpen->nLock>=0 );
+      if( pOpen->nLock==0 && pOpen->nPending>0 ){
+        int i;
+        for(i=0; i<pOpen->nPending; i++){
+          close(pOpen->aPending[i]);
+        }
+        sqlite3_free(pOpen->aPending);
+        pOpen->nPending = 0;
+        pOpen->aPending = 0;
+      }
+    }
+  }
+  leaveMutex();
+  if( rc==SQLITE_OK ) pFile->locktype = locktype;
+  return rc;
+}
+
+/*
+** This function performs the parts of the "close file" operation 
+** common to all locking schemes. It closes the directory and file
+** handles, if they are valid, and sets all fields of the unixFile
+** structure to 0.
+*/
+static int closeUnixFile(sqlite3_file *id){
+  unixFile *pFile = (unixFile*)id;
+  if( pFile ){
+    if( pFile->dirfd>=0 ){
+      close(pFile->dirfd);
+    }
+    if( pFile->h>=0 ){
+      close(pFile->h);
+    }
+    OSTRACE2("CLOSE   %-3d\n", pFile->h);
+    OpenCounter(-1);
+    memset(pFile, 0, sizeof(unixFile));
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Close a file.
+*/
+static int unixClose(sqlite3_file *id){
+  if( id ){
+    unixFile *pFile = (unixFile *)id;
+    unixUnlock(id, NO_LOCK);
+    enterMutex();
+    if( pFile->pOpen && pFile->pOpen->nLock ){
+      /* If there are outstanding locks, do not actually close the file just
+      ** yet because that would clear those locks.  Instead, add the file
+      ** descriptor to pOpen->aPending.  It will be automatically closed when
+      ** the last lock is cleared.
+      */
+      int *aNew;
+      struct openCnt *pOpen = pFile->pOpen;
+      aNew = sqlite3_realloc(pOpen->aPending, (pOpen->nPending+1)*sizeof(int) );
+      if( aNew==0 ){
+        /* If a malloc fails, just leak the file descriptor */
+      }else{
+        pOpen->aPending = aNew;
+        pOpen->aPending[pOpen->nPending] = pFile->h;
+        pOpen->nPending++;
+        pFile->h = -1;
+      }
+    }
+    releaseLockInfo(pFile->pLock);
+    releaseOpenCnt(pFile->pOpen);
+    closeUnixFile(id);
+    leaveMutex();
+  }
+  return SQLITE_OK;
+}
+
+
+#ifdef SQLITE_ENABLE_LOCKING_STYLE
+#pragma mark AFP Support
+
+/*
+ ** The afpLockingContext structure contains all afp lock specific state
+ */
+typedef struct afpLockingContext afpLockingContext;
+struct afpLockingContext {
+  unsigned long long sharedLockByte;
+  const char *filePath;
+};
+
+struct ByteRangeLockPB2
+{
+  unsigned long long offset;        /* offset to first byte to lock */
+  unsigned long long length;        /* nbr of bytes to lock */
+  unsigned long long retRangeStart; /* nbr of 1st byte locked if successful */
+  unsigned char unLockFlag;         /* 1 = unlock, 0 = lock */
+  unsigned char startEndFlag;       /* 1=rel to end of fork, 0=rel to start */
+  int fd;                           /* file desc to assoc this lock with */
+};
+
+#define afpfsByteRangeLock2FSCTL        _IOWR('z', 23, struct ByteRangeLockPB2)
+
+/* 
+** Return 0 on success, 1 on failure.  To match the behavior of the 
+** normal posix file locking (used in unixLock for example), we should 
+** provide 'richer' return codes - specifically to differentiate between
+** 'file busy' and 'file system error' results.
+*/
+static int _AFPFSSetLock(
+  const char *path, 
+  int fd, 
+  unsigned long long offset, 
+  unsigned long long length, 
+  int setLockFlag
+){
+  struct ByteRangeLockPB2       pb;
+  int                     err;
+  
+  pb.unLockFlag = setLockFlag ? 0 : 1;
+  pb.startEndFlag = 0;
+  pb.offset = offset;
+  pb.length = length; 
+  pb.fd = fd;
+  OSTRACE5("AFPLOCK setting lock %s for %d in range %llx:%llx\n", 
+    (setLockFlag?"ON":"OFF"), fd, offset, length);
+  err = fsctl(path, afpfsByteRangeLock2FSCTL, &pb, 0);
+  if ( err==-1 ) {
+    OSTRACE4("AFPLOCK failed to fsctl() '%s' %d %s\n", path, errno, 
+      strerror(errno));
+    return 1; /* error */
+  } else {
+    return 0;
+  }
+}
+
+/*
+ ** This routine checks if there is a RESERVED lock held on the specified
+ ** file by this or any other process. If such a lock is held, return
+ ** non-zero.  If the file is unlocked or holds only SHARED locks, then
+ ** return zero.
+ */
+static int afpCheckReservedLock(sqlite3_file *id, int *pResOut){
+  int r = 0;
+  unixFile *pFile = (unixFile*)id;
+  
+  assert( pFile ); 
+  afpLockingContext *context = (afpLockingContext *) pFile->lockingContext;
+  
+  /* Check if a thread in this process holds such a lock */
+  if( pFile->locktype>SHARED_LOCK ){
+    r = 1;
+  }
+  
+  /* Otherwise see if some other process holds it.
+   */
+  if ( !r ) {
+    /* lock the byte */
+    int failed = _AFPFSSetLock(context->filePath, pFile->h, RESERVED_BYTE, 1,1);  
+    if (failed) {
+      /* if we failed to get the lock then someone else must have it */
+      r = 1;
+    } else {
+      /* if we succeeded in taking the reserved lock, unlock it to restore
+      ** the original state */
+      _AFPFSSetLock(context->filePath, pFile->h, RESERVED_BYTE, 1, 0);
+    }
+  }
+  OSTRACE3("TEST WR-LOCK %d %d\n", pFile->h, r);
+  
+  *pResOut = r;
+  return SQLITE_OK;
+}
+
+/* AFP-style locking following the behavior of unixLock, see the unixLock 
+** function comments for details of lock management. */
+static int afpLock(sqlite3_file *id, int locktype){
+  int rc = SQLITE_OK;
+  unixFile *pFile = (unixFile*)id;
+  afpLockingContext *context = (afpLockingContext *) pFile->lockingContext;
+  
+  assert( pFile );
+  OSTRACE5("LOCK    %d %s was %s pid=%d\n", pFile->h,
+         locktypeName(locktype), locktypeName(pFile->locktype), getpid());
+
+  /* If there is already a lock of this type or more restrictive on the
+  ** unixFile, do nothing. Don't use the afp_end_lock: exit path, as
+  ** enterMutex() hasn't been called yet.
+  */
+  if( pFile->locktype>=locktype ){
+    OSTRACE3("LOCK    %d %s ok (already held)\n", pFile->h,
+           locktypeName(locktype));
+    return SQLITE_OK;
+  }
+
+  /* Make sure the locking sequence is correct
+  */
+  assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
+  assert( locktype!=PENDING_LOCK );
+  assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );
+  
+  /* This mutex is needed because pFile->pLock is shared across threads
+  */
+  enterMutex();
+
+  /* Make sure the current thread owns the pFile.
+  */
+  rc = transferOwnership(pFile);
+  if( rc!=SQLITE_OK ){
+    leaveMutex();
+    return rc;
+  }
+    
+  /* A PENDING lock is needed before acquiring a SHARED lock and before
+  ** acquiring an EXCLUSIVE lock.  For the SHARED lock, the PENDING will
+  ** be released.
+  */
+  if( locktype==SHARED_LOCK 
+      || (locktype==EXCLUSIVE_LOCK && pFile->locktype<PENDING_LOCK)
+  ){
+    int failed;
+    failed = _AFPFSSetLock(context->filePath, pFile->h, PENDING_BYTE, 1, 1);
+    if (failed) {
+      rc = SQLITE_BUSY;
+      goto afp_end_lock;
+    }
+  }
+  
+  /* If control gets to this point, then actually go ahead and make
+  ** operating system calls for the specified lock.
+  */
+  if( locktype==SHARED_LOCK ){
+    int lk, failed;
+    
+    /* Now get the read-lock */
+    /* note that the quality of the randomness doesn't matter that much */
+    lk = random(); 
+    context->sharedLockByte = (lk & 0x7fffffff)%(SHARED_SIZE - 1);
+    failed = _AFPFSSetLock(context->filePath, pFile->h, 
+      SHARED_FIRST+context->sharedLockByte, 1, 1);
+    
+    /* Drop the temporary PENDING lock */
+    if (_AFPFSSetLock(context->filePath, pFile->h, PENDING_BYTE, 1, 0)) {
+      rc = SQLITE_IOERR_UNLOCK;  /* This should never happen */
+      goto afp_end_lock;
+    }
+    
+    if( failed ){
+      rc = SQLITE_BUSY;
+    } else {
+      pFile->locktype = SHARED_LOCK;
+    }
+  }else{
+    /* The request was for a RESERVED or EXCLUSIVE lock.  It is
+    ** assumed that there is a SHARED or greater lock on the file
+    ** already.
+    */
+    int failed = 0;
+    assert( 0!=pFile->locktype );
+    if (locktype >= RESERVED_LOCK && pFile->locktype < RESERVED_LOCK) {
+        /* Acquire a RESERVED lock */
+        failed = _AFPFSSetLock(context->filePath, pFile->h, RESERVED_BYTE, 1,1);
+    }
+    if (!failed && locktype == EXCLUSIVE_LOCK) {
+      /* Acquire an EXCLUSIVE lock */
+        
+      /* Remove the shared lock before trying the range.  we'll need to 
+      ** reestablish the shared lock if we can't get the  afpUnlock
+      */
+      if (!_AFPFSSetLock(context->filePath, pFile->h, SHARED_FIRST +
+                         context->sharedLockByte, 1, 0)) {
+        /* now attemmpt to get the exclusive lock range */
+        failed = _AFPFSSetLock(context->filePath, pFile->h, SHARED_FIRST, 
+                               SHARED_SIZE, 1);
+        if (failed && _AFPFSSetLock(context->filePath, pFile->h, SHARED_FIRST +
+                                    context->sharedLockByte, 1, 1)) {
+          rc = SQLITE_IOERR_RDLOCK; /* this should never happen */
+        }
+      } else {
+        /* */
+        rc = SQLITE_IOERR_UNLOCK; /* this should never happen */
+      }
+    }
+    if( failed && rc == SQLITE_OK){
+      rc = SQLITE_BUSY;
+    }
+  }
+  
+  if( rc==SQLITE_OK ){
+    pFile->locktype = locktype;
+  }else if( locktype==EXCLUSIVE_LOCK ){
+    pFile->locktype = PENDING_LOCK;
+  }
+  
+afp_end_lock:
+  leaveMutex();
+  OSTRACE4("LOCK    %d %s %s\n", pFile->h, locktypeName(locktype), 
+         rc==SQLITE_OK ? "ok" : "failed");
+  return rc;
+}
+
+/*
+** Lower the locking level on file descriptor pFile to locktype.  locktype
+** must be either NO_LOCK or SHARED_LOCK.
+**
+** If the locking level of the file descriptor is already at or below
+** the requested locking level, this routine is a no-op.
+*/
+static int afpUnlock(sqlite3_file *id, int locktype) {
+  int rc = SQLITE_OK;
+  unixFile *pFile = (unixFile*)id;
+  afpLockingContext *context = (afpLockingContext *) pFile->lockingContext;
+
+  assert( pFile );
+  OSTRACE5("UNLOCK  %d %d was %d pid=%d\n", pFile->h, locktype,
+         pFile->locktype, getpid());
+  
+  assert( locktype<=SHARED_LOCK );
+  if( pFile->locktype<=locktype ){
+    return SQLITE_OK;
+  }
+  if( CHECK_THREADID(pFile) ){
+    return SQLITE_MISUSE;
+  }
+  enterMutex();
+  if( pFile->locktype>SHARED_LOCK ){
+    if( locktype==SHARED_LOCK ){
+      int failed = 0;
+
+      /* unlock the exclusive range - then re-establish the shared lock */
+      if (pFile->locktype==EXCLUSIVE_LOCK) {
+        failed = _AFPFSSetLock(context->filePath, pFile->h, SHARED_FIRST, 
+                                 SHARED_SIZE, 0);
+        if (!failed) {
+          /* successfully removed the exclusive lock */
+          if (_AFPFSSetLock(context->filePath, pFile->h, SHARED_FIRST+
+                            context->sharedLockByte, 1, 1)) {
+            /* failed to re-establish our shared lock */
+            rc = SQLITE_IOERR_RDLOCK; /* This should never happen */
+          }
+        } else {
+          /* This should never happen - failed to unlock the exclusive range */
+          rc = SQLITE_IOERR_UNLOCK;
+        } 
+      }
+    }
+    if (rc == SQLITE_OK && pFile->locktype>=PENDING_LOCK) {
+      if (_AFPFSSetLock(context->filePath, pFile->h, PENDING_BYTE, 1, 0)){
+        /* failed to release the pending lock */
+        rc = SQLITE_IOERR_UNLOCK; /* This should never happen */
+      }
+    } 
+    if (rc == SQLITE_OK && pFile->locktype>=RESERVED_LOCK) {
+      if (_AFPFSSetLock(context->filePath, pFile->h, RESERVED_BYTE, 1, 0)) {
+        /* failed to release the reserved lock */
+        rc = SQLITE_IOERR_UNLOCK;  /* This should never happen */
+      }
+    } 
+  }
+  if( locktype==NO_LOCK ){
+    int failed = _AFPFSSetLock(context->filePath, pFile->h, 
+                               SHARED_FIRST + context->sharedLockByte, 1, 0);
+    if (failed) {
+      rc = SQLITE_IOERR_UNLOCK;  /* This should never happen */
+    }
+  }
+  if (rc == SQLITE_OK)
+    pFile->locktype = locktype;
+  leaveMutex();
+  return rc;
+}
+
+/*
+** Close a file & cleanup AFP specific locking context 
+*/
+static int afpClose(sqlite3_file *id) {
+  if( id ){
+    unixFile *pFile = (unixFile*)id;
+    afpUnlock(id, NO_LOCK);
+    sqlite3_free(pFile->lockingContext);
+  }
+  return closeUnixFile(id);
+}
+
+
+#pragma mark flock() style locking
+
+/*
+** The flockLockingContext is not used
+*/
+typedef void flockLockingContext;
+
+static int flockCheckReservedLock(sqlite3_file *id, int *pResOut){
+  int r = 1;
+  unixFile *pFile = (unixFile*)id;
+  
+  if (pFile->locktype != RESERVED_LOCK) {
+    /* attempt to get the lock */
+    int rc = flock(pFile->h, LOCK_EX | LOCK_NB);
+    if (!rc) {
+      /* got the lock, unlock it */
+      flock(pFile->h, LOCK_UN);
+      r = 0;  /* no one has it reserved */
+    }
+  }
+
+  *pResOut = r;
+  return SQLITE_OK;
+}
+
+static int flockLock(sqlite3_file *id, int locktype) {
+  unixFile *pFile = (unixFile*)id;
+  
+  /* if we already have a lock, it is exclusive.  
+  ** Just adjust level and punt on outta here. */
+  if (pFile->locktype > NO_LOCK) {
+    pFile->locktype = locktype;
+    return SQLITE_OK;
+  }
+  
+  /* grab an exclusive lock */
+  int rc = flock(pFile->h, LOCK_EX | LOCK_NB);
+  if (rc) {
+    /* didn't get, must be busy */
+    return SQLITE_BUSY;
+  } else {
+    /* got it, set the type and return ok */
+    pFile->locktype = locktype;
+    return SQLITE_OK;
+  }
+}
+
+static int flockUnlock(sqlite3_file *id, int locktype) {
+  unixFile *pFile = (unixFile*)id;
+  
+  assert( locktype<=SHARED_LOCK );
+  
+  /* no-op if possible */
+  if( pFile->locktype==locktype ){
+    return SQLITE_OK;
+  }
+  
+  /* shared can just be set because we always have an exclusive */
+  if (locktype==SHARED_LOCK) {
+    pFile->locktype = locktype;
+    return SQLITE_OK;
+  }
+  
+  /* no, really, unlock. */
+  int rc = flock(pFile->h, LOCK_UN);
+  if (rc)
+    return SQLITE_IOERR_UNLOCK;
+  else {
+    pFile->locktype = NO_LOCK;
+    return SQLITE_OK;
+  }
+}
+
+/*
+** Close a file.
+*/
+static int flockClose(sqlite3_file *id) {
+  if( id ){
+    flockUnlock(id, NO_LOCK);
+  }
+  return closeUnixFile(id);
+}
+
+#pragma mark Old-School .lock file based locking
+
+static int dotlockCheckReservedLock(sqlite3_file *id, int *pResOut) {
+  int r = 1;
+  unixFile *pFile = (unixFile*)id;
+  char *zLockFile = (char *)pFile->lockingContext;
+
+  if (pFile->locktype != RESERVED_LOCK) {
+    struct stat statBuf;
+    if (lstat(zLockFile, &statBuf) != 0){
+      /* file does not exist, we could have it if we want it */
+      r = 0;
+    }
+  }
+
+  *pResOut = r;
+  return SQLITE_OK;
+}
+
+static int dotlockLock(sqlite3_file *id, int locktype) {
+  unixFile *pFile = (unixFile*)id;
+  int fd;
+  char *zLockFile = (char *)pFile->lockingContext;
+
+  /* if we already have a lock, it is exclusive.  
+  ** Just adjust level and punt on outta here. */
+  if (pFile->locktype > NO_LOCK) {
+    pFile->locktype = locktype;
+    
+    /* Always update the timestamp on the old file */
+    utimes(zLockFile, NULL);
+    return SQLITE_OK;
+  }
+  
+  /* check to see if lock file already exists */
+  struct stat statBuf;
+  if (lstat(zLockFile,&statBuf) == 0){
+    return SQLITE_BUSY; /* it does, busy */
+  }
+  
+  /* grab an exclusive lock */
+  fd = open(zLockFile,O_RDONLY|O_CREAT|O_EXCL,0600);
+  if( fd<0 ){
+    /* failed to open/create the file, someone else may have stolen the lock */
+    return SQLITE_BUSY; 
+  }
+  close(fd);
+  
+  /* got it, set the type and return ok */
+  pFile->locktype = locktype;
+  return SQLITE_OK;
+}
+
+static int dotlockUnlock(sqlite3_file *id, int locktype) {
+  unixFile *pFile = (unixFile*)id;
+  char *zLockFile = (char *)pFile->lockingContext;
+
+  assert( locktype<=SHARED_LOCK );
+  
+  /* no-op if possible */
+  if( pFile->locktype==locktype ){
+    return SQLITE_OK;
+  }
+  
+  /* shared can just be set because we always have an exclusive */
+  if (locktype==SHARED_LOCK) {
+    pFile->locktype = locktype;
+    return SQLITE_OK;
+  }
+  
+  /* no, really, unlock. */
+  unlink(zLockFile);
+  pFile->locktype = NO_LOCK;
+  return SQLITE_OK;
+}
+
+/*
+ ** Close a file.
+ */
+static int dotlockClose(sqlite3_file *id) {
+  if( id ){
+    unixFile *pFile = (unixFile*)id;
+    dotlockUnlock(id, NO_LOCK);
+    sqlite3_free(pFile->lockingContext);
+  }
+  return closeUnixFile(id);
+}
+
+
+#endif /* SQLITE_ENABLE_LOCKING_STYLE */
+
+/*
+** The nolockLockingContext is void
+*/
+typedef void nolockLockingContext;
+
+static int nolockCheckReservedLock(sqlite3_file *id, int *pResOut) {
+  *pResOut = 0;
+  return SQLITE_OK;
+}
+
+static int nolockLock(sqlite3_file *id, int locktype) {
+  return SQLITE_OK;
+}
+
+static int nolockUnlock(sqlite3_file *id, int locktype) {
+  return SQLITE_OK;
+}
+
+/*
+** Close a file.
+*/
+static int nolockClose(sqlite3_file *id) {
+  return closeUnixFile(id);
+}
+
+
+/*
+** Information and control of an open file handle.
+*/
+static int unixFileControl(sqlite3_file *id, int op, void *pArg){
+  switch( op ){
+    case SQLITE_FCNTL_LOCKSTATE: {
+      *(int*)pArg = ((unixFile*)id)->locktype;
+      return SQLITE_OK;
+    }
+  }
+  return SQLITE_ERROR;
+}
+
+/*
+** Return the sector size in bytes of the underlying block device for
+** the specified file. This is almost always 512 bytes, but may be
+** larger for some devices.
+**
+** SQLite code assumes this function cannot fail. It also assumes that
+** if two files are created in the same file-system directory (i.e.
+** a database and its journal file) that the sector size will be the
+** same for both.
+*/
+static int unixSectorSize(sqlite3_file *id){
+  return SQLITE_DEFAULT_SECTOR_SIZE;
+}
+
+/*
+** Return the device characteristics for the file. This is always 0.
+*/
+static int unixDeviceCharacteristics(sqlite3_file *id){
+  return 0;
+}
+
+/*
+** Initialize the contents of the unixFile structure pointed to by pId.
+**
+** When locking extensions are enabled, the filepath and locking style 
+** are needed to determine the unixFile pMethod to use for locking operations.
+** The locking-style specific lockingContext data structure is created 
+** and assigned here also.
+*/
+static int fillInUnixFile(
+  sqlite3_vfs *pVfs,      /* Pointer to vfs object */
+  int h,                  /* Open file descriptor of file being opened */
+  int dirfd,              /* Directory file descriptor */
+  sqlite3_file *pId,      /* Write to the unixFile structure here */
+  const char *zFilename,  /* Name of the file being opened */
+  int noLock              /* Omit locking if true */
+){
+  int eLockingStyle;
+  unixFile *pNew = (unixFile *)pId;
+  int rc = SQLITE_OK;
+
+  /* Macro to define the static contents of an sqlite3_io_methods 
+  ** structure for a unix backend file. Different locking methods
+  ** require different functions for the xClose, xLock, xUnlock and
+  ** xCheckReservedLock methods.
+  */
+  #define IOMETHODS(xClose, xLock, xUnlock, xCheckReservedLock) {    \
+    1,                          /* iVersion */                           \
+    xClose,                     /* xClose */                             \
+    unixRead,                   /* xRead */                              \
+    unixWrite,                  /* xWrite */                             \
+    unixTruncate,               /* xTruncate */                          \
+    unixSync,                   /* xSync */                              \
+    unixFileSize,               /* xFileSize */                          \
+    xLock,                      /* xLock */                              \
+    xUnlock,                    /* xUnlock */                            \
+    xCheckReservedLock,         /* xCheckReservedLock */                 \
+    unixFileControl,            /* xFileControl */                       \
+    unixSectorSize,             /* xSectorSize */                        \
+    unixDeviceCharacteristics   /* xDeviceCapabilities */                \
+  }
+  static sqlite3_io_methods aIoMethod[] = {
+    IOMETHODS(unixClose, unixLock, unixUnlock, unixCheckReservedLock) 
+   ,IOMETHODS(nolockClose, nolockLock, nolockUnlock, nolockCheckReservedLock)
+#ifdef SQLITE_ENABLE_LOCKING_STYLE
+   ,IOMETHODS(dotlockClose, dotlockLock, dotlockUnlock,dotlockCheckReservedLock)
+   ,IOMETHODS(flockClose, flockLock, flockUnlock, flockCheckReservedLock)
+   ,IOMETHODS(afpClose, afpLock, afpUnlock, afpCheckReservedLock)
+#endif
+  };
+  /* The order of the IOMETHODS macros above is important.  It must be the
+  ** same order as the LOCKING_STYLE numbers
+  */
+  assert(LOCKING_STYLE_POSIX==1);
+  assert(LOCKING_STYLE_NONE==2);
+  assert(LOCKING_STYLE_DOTFILE==3);
+  assert(LOCKING_STYLE_FLOCK==4);
+  assert(LOCKING_STYLE_AFP==5);
+
+  assert( pNew->pLock==NULL );
+  assert( pNew->pOpen==NULL );
+
+  OSTRACE3("OPEN    %-3d %s\n", h, zFilename);    
+  pNew->h = h;
+  pNew->dirfd = dirfd;
+  SET_THREADID(pNew);
+
+  if( noLock ){
+    eLockingStyle = LOCKING_STYLE_NONE;
+  }else{
+    eLockingStyle = detectLockingStyle(pVfs, zFilename, h);
+  }
+
+  switch( eLockingStyle ){
+
+    case LOCKING_STYLE_POSIX: {
+      enterMutex();
+      rc = findLockInfo(h, &pNew->pLock, &pNew->pOpen);
+      leaveMutex();
+      break;
+    }
+
+#ifdef SQLITE_ENABLE_LOCKING_STYLE
+    case LOCKING_STYLE_AFP: {
+      /* AFP locking uses the file path so it needs to be included in
+      ** the afpLockingContext.
+      */
+      afpLockingContext *pCtx;
+      pNew->lockingContext = pCtx = sqlite3_malloc( sizeof(*pCtx) );
+      if( pCtx==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        /* NB: zFilename exists and remains valid until the file is closed
+        ** according to requirement F11141.  So we do not need to make a
+        ** copy of the filename. */
+        pCtx->filePath = zFilename;
+        srandomdev();
+      }
+      break;
+    }
+
+    case LOCKING_STYLE_DOTFILE: {
+      /* Dotfile locking uses the file path so it needs to be included in
+      ** the dotlockLockingContext 
+      */
+      char *zLockFile;
+      int nFilename;
+      nFilename = strlen(zFilename) + 6;
+      zLockFile = (char *)sqlite3_malloc(nFilename);
+      if( zLockFile==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        sqlite3_snprintf(nFilename, zLockFile, "%s.lock", zFilename);
+      }
+      pNew->lockingContext = zLockFile;
+      break;
+    }
+
+    case LOCKING_STYLE_FLOCK: 
+    case LOCKING_STYLE_NONE: 
+      break;
+#endif
+  }
+
+  if( rc!=SQLITE_OK ){
+    if( dirfd>=0 ) close(dirfd);
+    close(h);
+  }else{
+    pNew->pMethod = &aIoMethod[eLockingStyle-1];
+    OpenCounter(+1);
+  }
+  return rc;
+}
+
+/*
+** Open a file descriptor to the directory containing file zFilename.
+** If successful, *pFd is set to the opened file descriptor and
+** SQLITE_OK is returned. If an error occurs, either SQLITE_NOMEM
+** or SQLITE_CANTOPEN is returned and *pFd is set to an undefined
+** value.
+**
+** If SQLITE_OK is returned, the caller is responsible for closing
+** the file descriptor *pFd using close().
+*/
+static int openDirectory(const char *zFilename, int *pFd){
+  int ii;
+  int fd = -1;
+  char zDirname[MAX_PATHNAME+1];
+
+  sqlite3_snprintf(MAX_PATHNAME, zDirname, "%s", zFilename);
+  for(ii=strlen(zDirname); ii>=0 && zDirname[ii]!='/'; ii--);
+  if( ii>0 ){
+    zDirname[ii] = '\0';
+    fd = open(zDirname, O_RDONLY|O_BINARY, 0);
+    if( fd>=0 ){
+#ifdef FD_CLOEXEC
+      fcntl(fd, F_SETFD, fcntl(fd, F_GETFD, 0) | FD_CLOEXEC);
+#endif
+      OSTRACE3("OPENDIR %-3d %s\n", fd, zDirname);
+    }
+  }
+  *pFd = fd;
+  return (fd>=0?SQLITE_OK:SQLITE_CANTOPEN);
+}
+
+/*
+** Create a temporary file name in zBuf.  zBuf must be allocated
+** by the calling process and must be big enough to hold at least
+** pVfs->mxPathname bytes.
+*/
+static int getTempname(int nBuf, char *zBuf){
+  static const char *azDirs[] = {
+     0,
+     "/var/tmp",
+     "/usr/tmp",
+     "/tmp",
+     ".",
+  };
+  static const unsigned char zChars[] =
+    "abcdefghijklmnopqrstuvwxyz"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+    "0123456789";
+  int i, j;
+  struct stat buf;
+  const char *zDir = ".";
+
+  /* It's odd to simulate an io-error here, but really this is just
+  ** using the io-error infrastructure to test that SQLite handles this
+  ** function failing. 
+  */
+  SimulateIOError( return SQLITE_IOERR );
+
+  azDirs[0] = sqlite3_temp_directory;
+  for(i=0; i<sizeof(azDirs)/sizeof(azDirs[0]); i++){
+    if( azDirs[i]==0 ) continue;
+    if( stat(azDirs[i], &buf) ) continue;
+    if( !S_ISDIR(buf.st_mode) ) continue;
+    if( access(azDirs[i], 07) ) continue;
+    zDir = azDirs[i];
+    break;
+  }
+
+  /* Check that the output buffer is large enough for the temporary file 
+  ** name. If it is not, return SQLITE_ERROR.
+  */
+  if( (strlen(zDir) + strlen(SQLITE_TEMP_FILE_PREFIX) + 17) >= nBuf ){
+    return SQLITE_ERROR;
+  }
+
+  do{
+    sqlite3_snprintf(nBuf-17, zBuf, "%s/"SQLITE_TEMP_FILE_PREFIX, zDir);
+    j = strlen(zBuf);
+    sqlite3_randomness(15, &zBuf[j]);
+    for(i=0; i<15; i++, j++){
+      zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
+    }
+    zBuf[j] = 0;
+  }while( access(zBuf,0)==0 );
+  return SQLITE_OK;
+}
+
+
+/*
+** Open the file zPath.
+** 
+** Previously, the SQLite OS layer used three functions in place of this
+** one:
+**
+**     sqlite3OsOpenReadWrite();
+**     sqlite3OsOpenReadOnly();
+**     sqlite3OsOpenExclusive();
+**
+** These calls correspond to the following combinations of flags:
+**
+**     ReadWrite() ->     (READWRITE | CREATE)
+**     ReadOnly()  ->     (READONLY) 
+**     OpenExclusive() -> (READWRITE | CREATE | EXCLUSIVE)
+**
+** The old OpenExclusive() accepted a boolean argument - "delFlag". If
+** true, the file was configured to be automatically deleted when the
+** file handle closed. To achieve the same effect using this new 
+** interface, add the DELETEONCLOSE flag to those specified above for 
+** OpenExclusive().
+*/
+static int unixOpen(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  sqlite3_file *pFile,
+  int flags,
+  int *pOutFlags
+){
+  int fd = 0;                    /* File descriptor returned by open() */
+  int dirfd = -1;                /* Directory file descriptor */
+  int oflags = 0;                /* Flags to pass to open() */
+  int eType = flags&0xFFFFFF00;  /* Type of file to open */
+  int noLock;                    /* True to omit locking primitives */
+
+  int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
+  int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
+  int isCreate     = (flags & SQLITE_OPEN_CREATE);
+  int isReadonly   = (flags & SQLITE_OPEN_READONLY);
+  int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);
+
+  /* If creating a master or main-file journal, this function will open
+  ** a file-descriptor on the directory too. The first time unixSync()
+  ** is called the directory file descriptor will be fsync()ed and close()d.
+  */
+  int isOpenDirectory = (isCreate && 
+      (eType==SQLITE_OPEN_MASTER_JOURNAL || eType==SQLITE_OPEN_MAIN_JOURNAL)
+  );
+
+  /* If argument zPath is a NULL pointer, this function is required to open
+  ** a temporary file. Use this buffer to store the file name in.
+  */
+  char zTmpname[MAX_PATHNAME+1];
+  const char *zName = zPath;
+
+  /* Check the following statements are true: 
+  **
+  **   (a) Exactly one of the READWRITE and READONLY flags must be set, and 
+  **   (b) if CREATE is set, then READWRITE must also be set, and
+  **   (c) if EXCLUSIVE is set, then CREATE must also be set.
+  **   (d) if DELETEONCLOSE is set, then CREATE must also be set.
+  */
+  assert((isReadonly==0 || isReadWrite==0) && (isReadWrite || isReadonly));
+  assert(isCreate==0 || isReadWrite);
+  assert(isExclusive==0 || isCreate);
+  assert(isDelete==0 || isCreate);
+
+  /* The main DB, main journal, and master journal are never automatically
+  ** deleted
+  */
+  assert( eType!=SQLITE_OPEN_MAIN_DB || !isDelete );
+  assert( eType!=SQLITE_OPEN_MAIN_JOURNAL || !isDelete );
+  assert( eType!=SQLITE_OPEN_MASTER_JOURNAL || !isDelete );
+
+  /* Assert that the upper layer has set one of the "file-type" flags. */
+  assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB 
+       || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL 
+       || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_MASTER_JOURNAL 
+       || eType==SQLITE_OPEN_TRANSIENT_DB
+  );
+
+  memset(pFile, 0, sizeof(unixFile));
+
+  if( !zName ){
+    int rc;
+    assert(isDelete && !isOpenDirectory);
+    rc = getTempname(MAX_PATHNAME+1, zTmpname);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    zName = zTmpname;
+  }
+
+  if( isReadonly )  oflags |= O_RDONLY;
+  if( isReadWrite ) oflags |= O_RDWR;
+  if( isCreate )    oflags |= O_CREAT;
+  if( isExclusive ) oflags |= (O_EXCL|O_NOFOLLOW);
+  oflags |= (O_LARGEFILE|O_BINARY);
+
+  fd = open(zName, oflags, isDelete?0600:SQLITE_DEFAULT_FILE_PERMISSIONS);
+  if( fd<0 && errno!=EISDIR && isReadWrite && !isExclusive ){
+    /* Failed to open the file for read/write access. Try read-only. */
+    flags &= ~(SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
+    flags |= SQLITE_OPEN_READONLY;
+    return unixOpen(pVfs, zPath, pFile, flags, pOutFlags);
+  }
+  if( fd<0 ){
+    return SQLITE_CANTOPEN;
+  }
+  if( isDelete ){
+    unlink(zName);
+  }
+  if( pOutFlags ){
+    *pOutFlags = flags;
+  }
+
+  assert(fd!=0);
+  if( isOpenDirectory ){
+    int rc = openDirectory(zPath, &dirfd);
+    if( rc!=SQLITE_OK ){
+      close(fd);
+      return rc;
+    }
+  }
+
+#ifdef FD_CLOEXEC
+  fcntl(fd, F_SETFD, fcntl(fd, F_GETFD, 0) | FD_CLOEXEC);
+#endif
+
+  noLock = eType!=SQLITE_OPEN_MAIN_DB;
+  return fillInUnixFile(pVfs, fd, dirfd, pFile, zPath, noLock);
+}
+
+/*
+** Delete the file at zPath. If the dirSync argument is true, fsync()
+** the directory after deleting the file.
+*/
+static int unixDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+  int rc = SQLITE_OK;
+  SimulateIOError(return SQLITE_IOERR_DELETE);
+  unlink(zPath);
+  if( dirSync ){
+    int fd;
+    rc = openDirectory(zPath, &fd);
+    if( rc==SQLITE_OK ){
+      if( fsync(fd) ){
+        rc = SQLITE_IOERR_DIR_FSYNC;
+      }
+      close(fd);
+    }
+  }
+  return rc;
+}
+
+/*
+** Test the existance of or access permissions of file zPath. The
+** test performed depends on the value of flags:
+**
+**     SQLITE_ACCESS_EXISTS: Return 1 if the file exists
+**     SQLITE_ACCESS_READWRITE: Return 1 if the file is read and writable.
+**     SQLITE_ACCESS_READONLY: Return 1 if the file is readable.
+**
+** Otherwise return 0.
+*/
+static int unixAccess(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int flags, 
+  int *pResOut
+){
+  int amode = 0;
+  SimulateIOError( return SQLITE_IOERR_ACCESS; );
+  switch( flags ){
+    case SQLITE_ACCESS_EXISTS:
+      amode = F_OK;
+      break;
+    case SQLITE_ACCESS_READWRITE:
+      amode = W_OK|R_OK;
+      break;
+    case SQLITE_ACCESS_READ:
+      amode = R_OK;
+      break;
+
+    default:
+      assert(!"Invalid flags argument");
+  }
+  *pResOut = (access(zPath, amode)==0);
+  return SQLITE_OK;
+}
+
+
+/*
+** Turn a relative pathname into a full pathname. The relative path
+** is stored as a nul-terminated string in the buffer pointed to by
+** zPath. 
+**
+** zOut points to a buffer of at least sqlite3_vfs.mxPathname bytes 
+** (in this case, MAX_PATHNAME bytes). The full-path is written to
+** this buffer before returning.
+*/
+static int unixFullPathname(
+  sqlite3_vfs *pVfs,            /* Pointer to vfs object */
+  const char *zPath,            /* Possibly relative input path */
+  int nOut,                     /* Size of output buffer in bytes */
+  char *zOut                    /* Output buffer */
+){
+
+  /* It's odd to simulate an io-error here, but really this is just
+  ** using the io-error infrastructure to test that SQLite handles this
+  ** function failing. This function could fail if, for example, the
+  ** current working directly has been unlinked.
+  */
+  SimulateIOError( return SQLITE_ERROR );
+
+  assert( pVfs->mxPathname==MAX_PATHNAME );
+  zOut[nOut-1] = '\0';
+  if( zPath[0]=='/' ){
+    sqlite3_snprintf(nOut, zOut, "%s", zPath);
+  }else{
+    int nCwd;
+    if( getcwd(zOut, nOut-1)==0 ){
+      return SQLITE_CANTOPEN;
+    }
+    nCwd = strlen(zOut);
+    sqlite3_snprintf(nOut-nCwd, &zOut[nCwd], "/%s", zPath);
+  }
+  return SQLITE_OK;
+
+#if 0
+  /*
+  ** Remove "/./" path elements and convert "/A/./" path elements
+  ** to just "/".
+  */
+  if( zFull ){
+    int i, j;
+    for(i=j=0; zFull[i]; i++){
+      if( zFull[i]=='/' ){
+        if( zFull[i+1]=='/' ) continue;
+        if( zFull[i+1]=='.' && zFull[i+2]=='/' ){
+          i += 1;
+          continue;
+        }
+        if( zFull[i+1]=='.' && zFull[i+2]=='.' && zFull[i+3]=='/' ){
+          while( j>0 && zFull[j-1]!='/' ){ j--; }
+          i += 3;
+          continue;
+        }
+      }
+      zFull[j++] = zFull[i];
+    }
+    zFull[j] = 0;
+  }
+#endif
+}
+
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+/*
+** Interfaces for opening a shared library, finding entry points
+** within the shared library, and closing the shared library.
+*/
+#include <dlfcn.h>
+static void *unixDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
+  return dlopen(zFilename, RTLD_NOW | RTLD_GLOBAL);
+}
+
+/*
+** SQLite calls this function immediately after a call to unixDlSym() or
+** unixDlOpen() fails (returns a null pointer). If a more detailed error
+** message is available, it is written to zBufOut. If no error message
+** is available, zBufOut is left unmodified and SQLite uses a default
+** error message.
+*/
+static void unixDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
+  char *zErr;
+  enterMutex();
+  zErr = dlerror();
+  if( zErr ){
+    sqlite3_snprintf(nBuf, zBufOut, "%s", zErr);
+  }
+  leaveMutex();
+}
+static void *unixDlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol){
+  return dlsym(pHandle, zSymbol);
+}
+static void unixDlClose(sqlite3_vfs *pVfs, void *pHandle){
+  dlclose(pHandle);
+}
+#else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
+  #define unixDlOpen  0
+  #define unixDlError 0
+  #define unixDlSym   0
+  #define unixDlClose 0
+#endif
+
+/*
+** Write nBuf bytes of random data to the supplied buffer zBuf.
+*/
+static int unixRandomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
+
+  assert(nBuf>=(sizeof(time_t)+sizeof(int)));
+
+  /* We have to initialize zBuf to prevent valgrind from reporting
+  ** errors.  The reports issued by valgrind are incorrect - we would
+  ** prefer that the randomness be increased by making use of the
+  ** uninitialized space in zBuf - but valgrind errors tend to worry
+  ** some users.  Rather than argue, it seems easier just to initialize
+  ** the whole array and silence valgrind, even if that means less randomness
+  ** in the random seed.
+  **
+  ** When testing, initializing zBuf[] to zero is all we do.  That means
+  ** that we always use the same random number sequence.  This makes the
+  ** tests repeatable.
+  */
+  memset(zBuf, 0, nBuf);
+#if !defined(SQLITE_TEST)
+  {
+    int pid, fd;
+    fd = open("/dev/urandom", O_RDONLY);
+    if( fd<0 ){
+      time_t t;
+      time(&t);
+      memcpy(zBuf, &t, sizeof(t));
+      pid = getpid();
+      memcpy(&zBuf[sizeof(t)], &pid, sizeof(pid));
+    }else{
+      read(fd, zBuf, nBuf);
+      close(fd);
+    }
+  }
+#endif
+  return SQLITE_OK;
+}
+
+
+/*
+** Sleep for a little while.  Return the amount of time slept.
+** The argument is the number of microseconds we want to sleep.
+** The return value is the number of microseconds of sleep actually
+** requested from the underlying operating system, a number which
+** might be greater than or equal to the argument, but not less
+** than the argument.
+*/
+static int unixSleep(sqlite3_vfs *pVfs, int microseconds){
+#if defined(HAVE_USLEEP) && HAVE_USLEEP
+  usleep(microseconds);
+  return microseconds;
+#else
+  int seconds = (microseconds+999999)/1000000;
+  sleep(seconds);
+  return seconds*1000000;
+#endif
+}
+
+/*
+** The following variable, if set to a non-zero value, becomes the result
+** returned from sqlite3OsCurrentTime().  This is used for testing.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_current_time = 0;
+#endif
+
+/*
+** Find the current time (in Universal Coordinated Time).  Write the
+** current time and date as a Julian Day number into *prNow and
+** return 0.  Return 1 if the time and date cannot be found.
+*/
+static int unixCurrentTime(sqlite3_vfs *pVfs, double *prNow){
+#ifdef NO_GETTOD
+  time_t t;
+  time(&t);
+  *prNow = t/86400.0 + 2440587.5;
+#else
+  struct timeval sNow;
+  gettimeofday(&sNow, 0);
+  *prNow = 2440587.5 + sNow.tv_sec/86400.0 + sNow.tv_usec/86400000000.0;
+#endif
+#ifdef SQLITE_TEST
+  if( sqlite3_current_time ){
+    *prNow = sqlite3_current_time/86400.0 + 2440587.5;
+  }
+#endif
+  return 0;
+}
+
+static int unixGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
+  return 0;
+}
+
+/*
+** Initialize the operating system interface.
+*/
+int sqlite3_os_init(void){ 
+  /* Macro to define the static contents of an sqlite3_vfs structure for
+  ** the unix backend. The two parameters are the values to use for
+  ** the sqlite3_vfs.zName and sqlite3_vfs.pAppData fields, respectively.
+  ** 
+  */
+  #define UNIXVFS(zVfsName, pVfsAppData) {                  \
+    1,                    /* iVersion */                    \
+    sizeof(unixFile),     /* szOsFile */                    \
+    MAX_PATHNAME,         /* mxPathname */                  \
+    0,                    /* pNext */                       \
+    zVfsName,             /* zName */                       \
+    (void *)pVfsAppData,  /* pAppData */                    \
+    unixOpen,             /* xOpen */                       \
+    unixDelete,           /* xDelete */                     \
+    unixAccess,           /* xAccess */                     \
+    unixFullPathname,     /* xFullPathname */               \
+    unixDlOpen,           /* xDlOpen */                     \
+    unixDlError,          /* xDlError */                    \
+    unixDlSym,            /* xDlSym */                      \
+    unixDlClose,          /* xDlClose */                    \
+    unixRandomness,       /* xRandomness */                 \
+    unixSleep,            /* xSleep */                      \
+    unixCurrentTime,      /* xCurrentTime */                \
+    unixGetLastError      /* xGetLastError */               \
+  }
+
+  static sqlite3_vfs unixVfs = UNIXVFS("unix", 0);
+#ifdef SQLITE_ENABLE_LOCKING_STYLE
+#if 0
+  int i;
+  static sqlite3_vfs aVfs[] = {
+    UNIXVFS("unix-posix",   LOCKING_STYLE_POSIX), 
+    UNIXVFS("unix-afp",     LOCKING_STYLE_AFP), 
+    UNIXVFS("unix-flock",   LOCKING_STYLE_FLOCK), 
+    UNIXVFS("unix-dotfile", LOCKING_STYLE_DOTFILE), 
+    UNIXVFS("unix-none",    LOCKING_STYLE_NONE)
+  };
+  for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){
+    sqlite3_vfs_register(&aVfs[i], 0);
+  }
+#endif
+#endif
+  sqlite3_vfs_register(&unixVfs, 1);
+  return SQLITE_OK; 
+}
+
+/*
+** Shutdown the operating system interface. This is a no-op for unix.
+*/
+int sqlite3_os_end(void){ 
+  return SQLITE_OK; 
+}
+ 
+#endif /* SQLITE_OS_UNIX */
diff --git a/third_party/sqlite/src/os_win.c b/third_party/sqlite/src/os_win.c
new file mode 100755
index 0000000..ec30add
--- /dev/null
+++ b/third_party/sqlite/src/os_win.c
@@ -0,0 +1,1638 @@
+/*
+** 2004 May 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code that is specific to windows.
+**
+** $Id: os_win.c,v 1.132 2008/07/31 01:34:34 shane Exp $
+*/
+#include "sqliteInt.h"
+#if SQLITE_OS_WIN               /* This file is used for windows only */
+
+
+/*
+** A Note About Memory Allocation:
+**
+** This driver uses malloc()/free() directly rather than going through
+** the SQLite-wrappers sqlite3_malloc()/sqlite3_free().  Those wrappers
+** are designed for use on embedded systems where memory is scarce and
+** malloc failures happen frequently.  Win32 does not typically run on
+** embedded systems, and when it does the developers normally have bigger
+** problems to worry about than running out of memory.  So there is not
+** a compelling need to use the wrappers.
+**
+** But there is a good reason to not use the wrappers.  If we use the
+** wrappers then we will get simulated malloc() failures within this
+** driver.  And that causes all kinds of problems for our tests.  We
+** could enhance SQLite to deal with simulated malloc failures within
+** the OS driver, but the code to deal with those failure would not
+** be exercised on Linux (which does not need to malloc() in the driver)
+** and so we would have difficulty writing coverage tests for that
+** code.  Better to leave the code out, we think.
+**
+** The point of this discussion is as follows:  When creating a new
+** OS layer for an embedded system, if you use this file as an example,
+** avoid the use of malloc()/free().  Those routines work ok on windows
+** desktops but not so well in embedded systems.
+*/
+
+#include <winbase.h>
+
+#ifdef __CYGWIN__
+# include <sys/cygwin.h>
+#endif
+
+/*
+** Macros used to determine whether or not to use threads.
+*/
+#if defined(THREADSAFE) && THREADSAFE
+# define SQLITE_W32_THREADS 1
+#endif
+
+/*
+** Include code that is common to all os_*.c files
+*/
+#include "os_common.h"
+
+/*
+** Determine if we are dealing with WindowsCE - which has a much
+** reduced API.
+*/
+#if defined(SQLITE_OS_WINCE)
+# define AreFileApisANSI() 1
+#endif
+
+/*
+** WinCE lacks native support for file locking so we have to fake it
+** with some code of our own.
+*/
+#if SQLITE_OS_WINCE
+typedef struct winceLock {
+  int nReaders;       /* Number of reader locks obtained */
+  BOOL bPending;      /* Indicates a pending lock has been obtained */
+  BOOL bReserved;     /* Indicates a reserved lock has been obtained */
+  BOOL bExclusive;    /* Indicates an exclusive lock has been obtained */
+} winceLock;
+#endif
+
+/*
+** The winFile structure is a subclass of sqlite3_file* specific to the win32
+** portability layer.
+*/
+typedef struct winFile winFile;
+struct winFile {
+  const sqlite3_io_methods *pMethod;/* Must be first */
+  HANDLE h;               /* Handle for accessing the file */
+  unsigned char locktype; /* Type of lock currently held on this file */
+  short sharedLockByte;   /* Randomly chosen byte used as a shared lock */
+#if SQLITE_OS_WINCE
+  WCHAR *zDeleteOnClose;  /* Name of file to delete when closing */
+  HANDLE hMutex;          /* Mutex used to control access to shared lock */  
+  HANDLE hShared;         /* Shared memory segment used for locking */
+  winceLock local;        /* Locks obtained by this instance of winFile */
+  winceLock *shared;      /* Global shared lock memory for the file  */
+#endif
+};
+
+
+/*
+** The following variable is (normally) set once and never changes
+** thereafter.  It records whether the operating system is Win95
+** or WinNT.
+**
+** 0:   Operating system unknown.
+** 1:   Operating system is Win95.
+** 2:   Operating system is WinNT.
+**
+** In order to facilitate testing on a WinNT system, the test fixture
+** can manually set this value to 1 to emulate Win98 behavior.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_os_type = 0;
+#else
+static int sqlite3_os_type = 0;
+#endif
+
+/*
+** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,
+** or WinCE.  Return false (zero) for Win95, Win98, or WinME.
+**
+** Here is an interesting observation:  Win95, Win98, and WinME lack
+** the LockFileEx() API.  But we can still statically link against that
+** API as long as we don't call it win running Win95/98/ME.  A call to
+** this routine is used to determine if the host is Win95/98/ME or
+** WinNT/2K/XP so that we will know whether or not we can safely call
+** the LockFileEx() API.
+*/
+#if SQLITE_OS_WINCE
+# define isNT()  (1)
+#else
+  static int isNT(void){
+    if( sqlite3_os_type==0 ){
+      OSVERSIONINFO sInfo;
+      sInfo.dwOSVersionInfoSize = sizeof(sInfo);
+      GetVersionEx(&sInfo);
+      sqlite3_os_type = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
+    }
+    return sqlite3_os_type==2;
+  }
+#endif /* SQLITE_OS_WINCE */
+
+/*
+** Convert a UTF-8 string to microsoft unicode (UTF-16?). 
+**
+** Space to hold the returned string is obtained from malloc.
+*/
+static WCHAR *utf8ToUnicode(const char *zFilename){
+  int nChar;
+  WCHAR *zWideFilename;
+
+  nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, NULL, 0);
+  zWideFilename = malloc( nChar*sizeof(zWideFilename[0]) );
+  if( zWideFilename==0 ){
+    return 0;
+  }
+  nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, zWideFilename, nChar);
+  if( nChar==0 ){
+    free(zWideFilename);
+    zWideFilename = 0;
+  }
+  return zWideFilename;
+}
+
+/*
+** Convert microsoft unicode to UTF-8.  Space to hold the returned string is
+** obtained from malloc().
+*/
+static char *unicodeToUtf8(const WCHAR *zWideFilename){
+  int nByte;
+  char *zFilename;
+
+  nByte = WideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, 0, 0, 0, 0);
+  zFilename = malloc( nByte );
+  if( zFilename==0 ){
+    return 0;
+  }
+  nByte = WideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, zFilename, nByte,
+                              0, 0);
+  if( nByte == 0 ){
+    free(zFilename);
+    zFilename = 0;
+  }
+  return zFilename;
+}
+
+/*
+** Convert an ansi string to microsoft unicode, based on the
+** current codepage settings for file apis.
+** 
+** Space to hold the returned string is obtained
+** from malloc.
+*/
+static WCHAR *mbcsToUnicode(const char *zFilename){
+  int nByte;
+  WCHAR *zMbcsFilename;
+  int codepage = AreFileApisANSI() ? CP_ACP : CP_OEMCP;
+
+  nByte = MultiByteToWideChar(codepage, 0, zFilename, -1, NULL,0)*sizeof(WCHAR);
+  zMbcsFilename = malloc( nByte*sizeof(zMbcsFilename[0]) );
+  if( zMbcsFilename==0 ){
+    return 0;
+  }
+  nByte = MultiByteToWideChar(codepage, 0, zFilename, -1, zMbcsFilename, nByte);
+  if( nByte==0 ){
+    free(zMbcsFilename);
+    zMbcsFilename = 0;
+  }
+  return zMbcsFilename;
+}
+
+/*
+** Convert microsoft unicode to multibyte character string, based on the
+** user's Ansi codepage.
+**
+** Space to hold the returned string is obtained from
+** malloc().
+*/
+static char *unicodeToMbcs(const WCHAR *zWideFilename){
+  int nByte;
+  char *zFilename;
+  int codepage = AreFileApisANSI() ? CP_ACP : CP_OEMCP;
+
+  nByte = WideCharToMultiByte(codepage, 0, zWideFilename, -1, 0, 0, 0, 0);
+  zFilename = malloc( nByte );
+  if( zFilename==0 ){
+    return 0;
+  }
+  nByte = WideCharToMultiByte(codepage, 0, zWideFilename, -1, zFilename, nByte,
+                              0, 0);
+  if( nByte == 0 ){
+    free(zFilename);
+    zFilename = 0;
+  }
+  return zFilename;
+}
+
+/*
+** Convert multibyte character string to UTF-8.  Space to hold the
+** returned string is obtained from malloc().
+*/
+static char *mbcsToUtf8(const char *zFilename){
+  char *zFilenameUtf8;
+  WCHAR *zTmpWide;
+
+  zTmpWide = mbcsToUnicode(zFilename);
+  if( zTmpWide==0 ){
+    return 0;
+  }
+  zFilenameUtf8 = unicodeToUtf8(zTmpWide);
+  free(zTmpWide);
+  return zFilenameUtf8;
+}
+
+/*
+** Convert UTF-8 to multibyte character string.  Space to hold the 
+** returned string is obtained from malloc().
+*/
+static char *utf8ToMbcs(const char *zFilename){
+  char *zFilenameMbcs;
+  WCHAR *zTmpWide;
+
+  zTmpWide = utf8ToUnicode(zFilename);
+  if( zTmpWide==0 ){
+    return 0;
+  }
+  zFilenameMbcs = unicodeToMbcs(zTmpWide);
+  free(zTmpWide);
+  return zFilenameMbcs;
+}
+
+#if SQLITE_OS_WINCE
+/*************************************************************************
+** This section contains code for WinCE only.
+*/
+/*
+** WindowsCE does not have a localtime() function.  So create a
+** substitute.
+*/
+#include <time.h>
+struct tm *__cdecl localtime(const time_t *t)
+{
+  static struct tm y;
+  FILETIME uTm, lTm;
+  SYSTEMTIME pTm;
+  sqlite3_int64 t64;
+  t64 = *t;
+  t64 = (t64 + 11644473600)*10000000;
+  uTm.dwLowDateTime = t64 & 0xFFFFFFFF;
+  uTm.dwHighDateTime= t64 >> 32;
+  FileTimeToLocalFileTime(&uTm,&lTm);
+  FileTimeToSystemTime(&lTm,&pTm);
+  y.tm_year = pTm.wYear - 1900;
+  y.tm_mon = pTm.wMonth - 1;
+  y.tm_wday = pTm.wDayOfWeek;
+  y.tm_mday = pTm.wDay;
+  y.tm_hour = pTm.wHour;
+  y.tm_min = pTm.wMinute;
+  y.tm_sec = pTm.wSecond;
+  return &y;
+}
+
+/* This will never be called, but defined to make the code compile */
+#define GetTempPathA(a,b)
+
+#define LockFile(a,b,c,d,e)       winceLockFile(&a, b, c, d, e)
+#define UnlockFile(a,b,c,d,e)     winceUnlockFile(&a, b, c, d, e)
+#define LockFileEx(a,b,c,d,e,f)   winceLockFileEx(&a, b, c, d, e, f)
+
+#define HANDLE_TO_WINFILE(a) (winFile*)&((char*)a)[-offsetof(winFile,h)]
+
+/*
+** Acquire a lock on the handle h
+*/
+static void winceMutexAcquire(HANDLE h){
+   DWORD dwErr;
+   do {
+     dwErr = WaitForSingleObject(h, INFINITE);
+   } while (dwErr != WAIT_OBJECT_0 && dwErr != WAIT_ABANDONED);
+}
+/*
+** Release a lock acquired by winceMutexAcquire()
+*/
+#define winceMutexRelease(h) ReleaseMutex(h)
+
+/*
+** Create the mutex and shared memory used for locking in the file
+** descriptor pFile
+*/
+static BOOL winceCreateLock(const char *zFilename, winFile *pFile){
+  WCHAR *zTok;
+  WCHAR *zName = utf8ToUnicode(zFilename);
+  BOOL bInit = TRUE;
+
+  /* Initialize the local lockdata */
+  ZeroMemory(&pFile->local, sizeof(pFile->local));
+
+  /* Replace the backslashes from the filename and lowercase it
+  ** to derive a mutex name. */
+  zTok = CharLowerW(zName);
+  for (;*zTok;zTok++){
+    if (*zTok == '\\') *zTok = '_';
+  }
+
+  /* Create/open the named mutex */
+  pFile->hMutex = CreateMutexW(NULL, FALSE, zName);
+  if (!pFile->hMutex){
+    free(zName);
+    return FALSE;
+  }
+
+  /* Acquire the mutex before continuing */
+  winceMutexAcquire(pFile->hMutex);
+  
+  /* Since the names of named mutexes, semaphores, file mappings etc are 
+  ** case-sensitive, take advantage of that by uppercasing the mutex name
+  ** and using that as the shared filemapping name.
+  */
+  CharUpperW(zName);
+  pFile->hShared = CreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
+                                       PAGE_READWRITE, 0, sizeof(winceLock),
+                                       zName);  
+
+  /* Set a flag that indicates we're the first to create the memory so it 
+  ** must be zero-initialized */
+  if (GetLastError() == ERROR_ALREADY_EXISTS){
+    bInit = FALSE;
+  }
+
+  free(zName);
+
+  /* If we succeeded in making the shared memory handle, map it. */
+  if (pFile->hShared){
+    pFile->shared = (winceLock*)MapViewOfFile(pFile->hShared, 
+             FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, sizeof(winceLock));
+    /* If mapping failed, close the shared memory handle and erase it */
+    if (!pFile->shared){
+      CloseHandle(pFile->hShared);
+      pFile->hShared = NULL;
+    }
+  }
+
+  /* If shared memory could not be created, then close the mutex and fail */
+  if (pFile->hShared == NULL){
+    winceMutexRelease(pFile->hMutex);
+    CloseHandle(pFile->hMutex);
+    pFile->hMutex = NULL;
+    return FALSE;
+  }
+  
+  /* Initialize the shared memory if we're supposed to */
+  if (bInit) {
+    ZeroMemory(pFile->shared, sizeof(winceLock));
+  }
+
+  winceMutexRelease(pFile->hMutex);
+  return TRUE;
+}
+
+/*
+** Destroy the part of winFile that deals with wince locks
+*/
+static void winceDestroyLock(winFile *pFile){
+  if (pFile->hMutex){
+    /* Acquire the mutex */
+    winceMutexAcquire(pFile->hMutex);
+
+    /* The following blocks should probably assert in debug mode, but they
+       are to cleanup in case any locks remained open */
+    if (pFile->local.nReaders){
+      pFile->shared->nReaders --;
+    }
+    if (pFile->local.bReserved){
+      pFile->shared->bReserved = FALSE;
+    }
+    if (pFile->local.bPending){
+      pFile->shared->bPending = FALSE;
+    }
+    if (pFile->local.bExclusive){
+      pFile->shared->bExclusive = FALSE;
+    }
+
+    /* De-reference and close our copy of the shared memory handle */
+    UnmapViewOfFile(pFile->shared);
+    CloseHandle(pFile->hShared);
+
+    /* Done with the mutex */
+    winceMutexRelease(pFile->hMutex);    
+    CloseHandle(pFile->hMutex);
+    pFile->hMutex = NULL;
+  }
+}
+
+/* 
+** An implementation of the LockFile() API of windows for wince
+*/
+static BOOL winceLockFile(
+  HANDLE *phFile,
+  DWORD dwFileOffsetLow,
+  DWORD dwFileOffsetHigh,
+  DWORD nNumberOfBytesToLockLow,
+  DWORD nNumberOfBytesToLockHigh
+){
+  winFile *pFile = HANDLE_TO_WINFILE(phFile);
+  BOOL bReturn = FALSE;
+
+  if (!pFile->hMutex) return TRUE;
+  winceMutexAcquire(pFile->hMutex);
+
+  /* Wanting an exclusive lock? */
+  if (dwFileOffsetLow == SHARED_FIRST
+       && nNumberOfBytesToLockLow == SHARED_SIZE){
+    if (pFile->shared->nReaders == 0 && pFile->shared->bExclusive == 0){
+       pFile->shared->bExclusive = TRUE;
+       pFile->local.bExclusive = TRUE;
+       bReturn = TRUE;
+    }
+  }
+
+  /* Want a read-only lock? */
+  else if ((dwFileOffsetLow >= SHARED_FIRST &&
+            dwFileOffsetLow < SHARED_FIRST + SHARED_SIZE) &&
+            nNumberOfBytesToLockLow == 1){
+    if (pFile->shared->bExclusive == 0){
+      pFile->local.nReaders ++;
+      if (pFile->local.nReaders == 1){
+        pFile->shared->nReaders ++;
+      }
+      bReturn = TRUE;
+    }
+  }
+
+  /* Want a pending lock? */
+  else if (dwFileOffsetLow == PENDING_BYTE && nNumberOfBytesToLockLow == 1){
+    /* If no pending lock has been acquired, then acquire it */
+    if (pFile->shared->bPending == 0) {
+      pFile->shared->bPending = TRUE;
+      pFile->local.bPending = TRUE;
+      bReturn = TRUE;
+    }
+  }
+  /* Want a reserved lock? */
+  else if (dwFileOffsetLow == RESERVED_BYTE && nNumberOfBytesToLockLow == 1){
+    if (pFile->shared->bReserved == 0) {
+      pFile->shared->bReserved = TRUE;
+      pFile->local.bReserved = TRUE;
+      bReturn = TRUE;
+    }
+  }
+
+  winceMutexRelease(pFile->hMutex);
+  return bReturn;
+}
+
+/*
+** An implementation of the UnlockFile API of windows for wince
+*/
+static BOOL winceUnlockFile(
+  HANDLE *phFile,
+  DWORD dwFileOffsetLow,
+  DWORD dwFileOffsetHigh,
+  DWORD nNumberOfBytesToUnlockLow,
+  DWORD nNumberOfBytesToUnlockHigh
+){
+  winFile *pFile = HANDLE_TO_WINFILE(phFile);
+  BOOL bReturn = FALSE;
+
+  if (!pFile->hMutex) return TRUE;
+  winceMutexAcquire(pFile->hMutex);
+
+  /* Releasing a reader lock or an exclusive lock */
+  if (dwFileOffsetLow >= SHARED_FIRST &&
+       dwFileOffsetLow < SHARED_FIRST + SHARED_SIZE){
+    /* Did we have an exclusive lock? */
+    if (pFile->local.bExclusive){
+      pFile->local.bExclusive = FALSE;
+      pFile->shared->bExclusive = FALSE;
+      bReturn = TRUE;
+    }
+
+    /* Did we just have a reader lock? */
+    else if (pFile->local.nReaders){
+      pFile->local.nReaders --;
+      if (pFile->local.nReaders == 0)
+      {
+        pFile->shared->nReaders --;
+      }
+      bReturn = TRUE;
+    }
+  }
+
+  /* Releasing a pending lock */
+  else if (dwFileOffsetLow == PENDING_BYTE && nNumberOfBytesToUnlockLow == 1){
+    if (pFile->local.bPending){
+      pFile->local.bPending = FALSE;
+      pFile->shared->bPending = FALSE;
+      bReturn = TRUE;
+    }
+  }
+  /* Releasing a reserved lock */
+  else if (dwFileOffsetLow == RESERVED_BYTE && nNumberOfBytesToUnlockLow == 1){
+    if (pFile->local.bReserved) {
+      pFile->local.bReserved = FALSE;
+      pFile->shared->bReserved = FALSE;
+      bReturn = TRUE;
+    }
+  }
+
+  winceMutexRelease(pFile->hMutex);
+  return bReturn;
+}
+
+/*
+** An implementation of the LockFileEx() API of windows for wince
+*/
+static BOOL winceLockFileEx(
+  HANDLE *phFile,
+  DWORD dwFlags,
+  DWORD dwReserved,
+  DWORD nNumberOfBytesToLockLow,
+  DWORD nNumberOfBytesToLockHigh,
+  LPOVERLAPPED lpOverlapped
+){
+  /* If the caller wants a shared read lock, forward this call
+  ** to winceLockFile */
+  if (lpOverlapped->Offset == SHARED_FIRST &&
+      dwFlags == 1 &&
+      nNumberOfBytesToLockLow == SHARED_SIZE){
+    return winceLockFile(phFile, SHARED_FIRST, 0, 1, 0);
+  }
+  return FALSE;
+}
+/*
+** End of the special code for wince
+*****************************************************************************/
+#endif /* SQLITE_OS_WINCE */
+
+/*****************************************************************************
+** The next group of routines implement the I/O methods specified
+** by the sqlite3_io_methods object.
+******************************************************************************/
+
+/*
+** Close a file.
+**
+** It is reported that an attempt to close a handle might sometimes
+** fail.  This is a very unreasonable result, but windows is notorious
+** for being unreasonable so I do not doubt that it might happen.  If
+** the close fails, we pause for 100 milliseconds and try again.  As
+** many as MX_CLOSE_ATTEMPT attempts to close the handle are made before
+** giving up and returning an error.
+*/
+#define MX_CLOSE_ATTEMPT 3
+static int winClose(sqlite3_file *id){
+  int rc, cnt = 0;
+  winFile *pFile = (winFile*)id;
+  OSTRACE2("CLOSE %d\n", pFile->h);
+  do{
+    rc = CloseHandle(pFile->h);
+  }while( rc==0 && cnt++ < MX_CLOSE_ATTEMPT && (Sleep(100), 1) );
+#if SQLITE_OS_WINCE
+#define WINCE_DELETION_ATTEMPTS 3
+  winceDestroyLock(pFile);
+  if( pFile->zDeleteOnClose ){
+    int cnt = 0;
+    while(
+           DeleteFileW(pFile->zDeleteOnClose)==0
+        && GetFileAttributesW(pFile->zDeleteOnClose)!=0xffffffff 
+        && cnt++ < WINCE_DELETION_ATTEMPTS
+    ){
+       Sleep(100);  /* Wait a little before trying again */
+    }
+    free(pFile->zDeleteOnClose);
+  }
+#endif
+  OpenCounter(-1);
+  return rc ? SQLITE_OK : SQLITE_IOERR;
+}
+
+/*
+** Some microsoft compilers lack this definition.
+*/
+#ifndef INVALID_SET_FILE_POINTER
+# define INVALID_SET_FILE_POINTER ((DWORD)-1)
+#endif
+
+/*
+** Read data from a file into a buffer.  Return SQLITE_OK if all
+** bytes were read successfully and SQLITE_IOERR if anything goes
+** wrong.
+*/
+static int winRead(
+  sqlite3_file *id,          /* File to read from */
+  void *pBuf,                /* Write content into this buffer */
+  int amt,                   /* Number of bytes to read */
+  sqlite3_int64 offset       /* Begin reading at this offset */
+){
+  LONG upperBits = (offset>>32) & 0x7fffffff;
+  LONG lowerBits = offset & 0xffffffff;
+  DWORD rc;
+  DWORD got;
+  winFile *pFile = (winFile*)id;
+  assert( id!=0 );
+  SimulateIOError(return SQLITE_IOERR_READ);
+  OSTRACE3("READ %d lock=%d\n", pFile->h, pFile->locktype);
+  rc = SetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
+  if( rc==INVALID_SET_FILE_POINTER && GetLastError()!=NO_ERROR ){
+    return SQLITE_FULL;
+  }
+  if( !ReadFile(pFile->h, pBuf, amt, &got, 0) ){
+    return SQLITE_IOERR_READ;
+  }
+  if( got==(DWORD)amt ){
+    return SQLITE_OK;
+  }else{
+    memset(&((char*)pBuf)[got], 0, amt-got);
+    return SQLITE_IOERR_SHORT_READ;
+  }
+}
+
+/*
+** Write data from a buffer into a file.  Return SQLITE_OK on success
+** or some other error code on failure.
+*/
+static int winWrite(
+  sqlite3_file *id,         /* File to write into */
+  const void *pBuf,         /* The bytes to be written */
+  int amt,                  /* Number of bytes to write */
+  sqlite3_int64 offset      /* Offset into the file to begin writing at */
+){
+  LONG upperBits = (offset>>32) & 0x7fffffff;
+  LONG lowerBits = offset & 0xffffffff;
+  DWORD rc;
+  DWORD wrote;
+  winFile *pFile = (winFile*)id;
+  assert( id!=0 );
+  SimulateIOError(return SQLITE_IOERR_WRITE);
+  SimulateDiskfullError(return SQLITE_FULL);
+  OSTRACE3("WRITE %d lock=%d\n", pFile->h, pFile->locktype);
+  rc = SetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
+  if( rc==INVALID_SET_FILE_POINTER && GetLastError()!=NO_ERROR ){
+    return SQLITE_FULL;
+  }
+  assert( amt>0 );
+  while(
+     amt>0
+     && (rc = WriteFile(pFile->h, pBuf, amt, &wrote, 0))!=0
+     && wrote>0
+  ){
+    amt -= wrote;
+    pBuf = &((char*)pBuf)[wrote];
+  }
+  if( !rc || amt>(int)wrote ){
+    return SQLITE_FULL;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Truncate an open file to a specified size
+*/
+static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
+  LONG upperBits = (nByte>>32) & 0x7fffffff;
+  LONG lowerBits = nByte & 0xffffffff;
+  winFile *pFile = (winFile*)id;
+  OSTRACE3("TRUNCATE %d %lld\n", pFile->h, nByte);
+  SimulateIOError(return SQLITE_IOERR_TRUNCATE);
+  SetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
+  SetEndOfFile(pFile->h);
+  return SQLITE_OK;
+}
+
+#ifdef SQLITE_TEST
+/*
+** Count the number of fullsyncs and normal syncs.  This is used to test
+** that syncs and fullsyncs are occuring at the right times.
+*/
+int sqlite3_sync_count = 0;
+int sqlite3_fullsync_count = 0;
+#endif
+
+/*
+** Make sure all writes to a particular file are committed to disk.
+*/
+static int winSync(sqlite3_file *id, int flags){
+  winFile *pFile = (winFile*)id;
+  OSTRACE3("SYNC %d lock=%d\n", pFile->h, pFile->locktype);
+#ifdef SQLITE_TEST
+  if( flags & SQLITE_SYNC_FULL ){
+    sqlite3_fullsync_count++;
+  }
+  sqlite3_sync_count++;
+#endif
+  if( FlushFileBuffers(pFile->h) ){
+    return SQLITE_OK;
+  }else{
+    return SQLITE_IOERR;
+  }
+}
+
+/*
+** Determine the current size of a file in bytes
+*/
+static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){
+  winFile *pFile = (winFile*)id;
+  DWORD upperBits, lowerBits;
+  SimulateIOError(return SQLITE_IOERR_FSTAT);
+  lowerBits = GetFileSize(pFile->h, &upperBits);
+  *pSize = (((sqlite3_int64)upperBits)<<32) + lowerBits;
+  return SQLITE_OK;
+}
+
+/*
+** LOCKFILE_FAIL_IMMEDIATELY is undefined on some Windows systems.
+*/
+#ifndef LOCKFILE_FAIL_IMMEDIATELY
+# define LOCKFILE_FAIL_IMMEDIATELY 1
+#endif
+
+/*
+** Acquire a reader lock.
+** Different API routines are called depending on whether or not this
+** is Win95 or WinNT.
+*/
+static int getReadLock(winFile *pFile){
+  int res;
+  if( isNT() ){
+    OVERLAPPED ovlp;
+    ovlp.Offset = SHARED_FIRST;
+    ovlp.OffsetHigh = 0;
+    ovlp.hEvent = 0;
+    res = LockFileEx(pFile->h, LOCKFILE_FAIL_IMMEDIATELY,
+                     0, SHARED_SIZE, 0, &ovlp);
+  }else{
+    int lk;
+    sqlite3_randomness(sizeof(lk), &lk);
+    pFile->sharedLockByte = (lk & 0x7fffffff)%(SHARED_SIZE - 1);
+    res = LockFile(pFile->h, SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
+  }
+  return res;
+}
+
+/*
+** Undo a readlock
+*/
+static int unlockReadLock(winFile *pFile){
+  int res;
+  if( isNT() ){
+    res = UnlockFile(pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
+  }else{
+    res = UnlockFile(pFile->h, SHARED_FIRST + pFile->sharedLockByte, 0, 1, 0);
+  }
+  return res;
+}
+
+/*
+** Lock the file with the lock specified by parameter locktype - one
+** of the following:
+**
+**     (1) SHARED_LOCK
+**     (2) RESERVED_LOCK
+**     (3) PENDING_LOCK
+**     (4) EXCLUSIVE_LOCK
+**
+** Sometimes when requesting one lock state, additional lock states
+** are inserted in between.  The locking might fail on one of the later
+** transitions leaving the lock state different from what it started but
+** still short of its goal.  The following chart shows the allowed
+** transitions and the inserted intermediate states:
+**
+**    UNLOCKED -> SHARED
+**    SHARED -> RESERVED
+**    SHARED -> (PENDING) -> EXCLUSIVE
+**    RESERVED -> (PENDING) -> EXCLUSIVE
+**    PENDING -> EXCLUSIVE
+**
+** This routine will only increase a lock.  The winUnlock() routine
+** erases all locks at once and returns us immediately to locking level 0.
+** It is not possible to lower the locking level one step at a time.  You
+** must go straight to locking level 0.
+*/
+static int winLock(sqlite3_file *id, int locktype){
+  int rc = SQLITE_OK;    /* Return code from subroutines */
+  int res = 1;           /* Result of a windows lock call */
+  int newLocktype;       /* Set pFile->locktype to this value before exiting */
+  int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
+  winFile *pFile = (winFile*)id;
+
+  assert( pFile!=0 );
+  OSTRACE5("LOCK %d %d was %d(%d)\n",
+          pFile->h, locktype, pFile->locktype, pFile->sharedLockByte);
+
+  /* If there is already a lock of this type or more restrictive on the
+  ** OsFile, do nothing. Don't use the end_lock: exit path, as
+  ** sqlite3OsEnterMutex() hasn't been called yet.
+  */
+  if( pFile->locktype>=locktype ){
+    return SQLITE_OK;
+  }
+
+  /* Make sure the locking sequence is correct
+  */
+  assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
+  assert( locktype!=PENDING_LOCK );
+  assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );
+
+  /* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
+  ** a SHARED lock.  If we are acquiring a SHARED lock, the acquisition of
+  ** the PENDING_LOCK byte is temporary.
+  */
+  newLocktype = pFile->locktype;
+  if( pFile->locktype==NO_LOCK
+   || (locktype==EXCLUSIVE_LOCK && pFile->locktype==RESERVED_LOCK)
+  ){
+    int cnt = 3;
+    while( cnt-->0 && (res = LockFile(pFile->h, PENDING_BYTE, 0, 1, 0))==0 ){
+      /* Try 3 times to get the pending lock.  The pending lock might be
+      ** held by another reader process who will release it momentarily.
+      */
+      OSTRACE2("could not get a PENDING lock. cnt=%d\n", cnt);
+      Sleep(1);
+    }
+    gotPendingLock = res;
+  }
+
+  /* Acquire a shared lock
+  */
+  if( locktype==SHARED_LOCK && res ){
+    assert( pFile->locktype==NO_LOCK );
+    res = getReadLock(pFile);
+    if( res ){
+      newLocktype = SHARED_LOCK;
+    }
+  }
+
+  /* Acquire a RESERVED lock
+  */
+  if( locktype==RESERVED_LOCK && res ){
+    assert( pFile->locktype==SHARED_LOCK );
+    res = LockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
+    if( res ){
+      newLocktype = RESERVED_LOCK;
+    }
+  }
+
+  /* Acquire a PENDING lock
+  */
+  if( locktype==EXCLUSIVE_LOCK && res ){
+    newLocktype = PENDING_LOCK;
+    gotPendingLock = 0;
+  }
+
+  /* Acquire an EXCLUSIVE lock
+  */
+  if( locktype==EXCLUSIVE_LOCK && res ){
+    assert( pFile->locktype>=SHARED_LOCK );
+    res = unlockReadLock(pFile);
+    OSTRACE2("unreadlock = %d\n", res);
+    res = LockFile(pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
+    if( res ){
+      newLocktype = EXCLUSIVE_LOCK;
+    }else{
+      OSTRACE2("error-code = %d\n", GetLastError());
+      getReadLock(pFile);
+    }
+  }
+
+  /* If we are holding a PENDING lock that ought to be released, then
+  ** release it now.
+  */
+  if( gotPendingLock && locktype==SHARED_LOCK ){
+    UnlockFile(pFile->h, PENDING_BYTE, 0, 1, 0);
+  }
+
+  /* Update the state of the lock has held in the file descriptor then
+  ** return the appropriate result code.
+  */
+  if( res ){
+    rc = SQLITE_OK;
+  }else{
+    OSTRACE4("LOCK FAILED %d trying for %d but got %d\n", pFile->h,
+           locktype, newLocktype);
+    rc = SQLITE_BUSY;
+  }
+  pFile->locktype = newLocktype;
+  return rc;
+}
+
+/*
+** This routine checks if there is a RESERVED lock held on the specified
+** file by this or any other process. If such a lock is held, return
+** non-zero, otherwise zero.
+*/
+static int winCheckReservedLock(sqlite3_file *id, int *pResOut){
+  int rc;
+  winFile *pFile = (winFile*)id;
+  assert( pFile!=0 );
+  if( pFile->locktype>=RESERVED_LOCK ){
+    rc = 1;
+    OSTRACE3("TEST WR-LOCK %d %d (local)\n", pFile->h, rc);
+  }else{
+    rc = LockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
+    if( rc ){
+      UnlockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
+    }
+    rc = !rc;
+    OSTRACE3("TEST WR-LOCK %d %d (remote)\n", pFile->h, rc);
+  }
+  *pResOut = rc;
+  return SQLITE_OK;
+}
+
+/*
+** Lower the locking level on file descriptor id to locktype.  locktype
+** must be either NO_LOCK or SHARED_LOCK.
+**
+** If the locking level of the file descriptor is already at or below
+** the requested locking level, this routine is a no-op.
+**
+** It is not possible for this routine to fail if the second argument
+** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine
+** might return SQLITE_IOERR;
+*/
+static int winUnlock(sqlite3_file *id, int locktype){
+  int type;
+  winFile *pFile = (winFile*)id;
+  int rc = SQLITE_OK;
+  assert( pFile!=0 );
+  assert( locktype<=SHARED_LOCK );
+  OSTRACE5("UNLOCK %d to %d was %d(%d)\n", pFile->h, locktype,
+          pFile->locktype, pFile->sharedLockByte);
+  type = pFile->locktype;
+  if( type>=EXCLUSIVE_LOCK ){
+    UnlockFile(pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
+    if( locktype==SHARED_LOCK && !getReadLock(pFile) ){
+      /* This should never happen.  We should always be able to
+      ** reacquire the read lock */
+      rc = SQLITE_IOERR_UNLOCK;
+    }
+  }
+  if( type>=RESERVED_LOCK ){
+    UnlockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
+  }
+  if( locktype==NO_LOCK && type>=SHARED_LOCK ){
+    unlockReadLock(pFile);
+  }
+  if( type>=PENDING_LOCK ){
+    UnlockFile(pFile->h, PENDING_BYTE, 0, 1, 0);
+  }
+  pFile->locktype = locktype;
+  return rc;
+}
+
+/*
+** Control and query of the open file handle.
+*/
+static int winFileControl(sqlite3_file *id, int op, void *pArg){
+  switch( op ){
+    case SQLITE_FCNTL_LOCKSTATE: {
+      *(int*)pArg = ((winFile*)id)->locktype;
+      return SQLITE_OK;
+    }
+  }
+  return SQLITE_ERROR;
+}
+
+/*
+** Return the sector size in bytes of the underlying block device for
+** the specified file. This is almost always 512 bytes, but may be
+** larger for some devices.
+**
+** SQLite code assumes this function cannot fail. It also assumes that
+** if two files are created in the same file-system directory (i.e.
+** a database and its journal file) that the sector size will be the
+** same for both.
+*/
+static int winSectorSize(sqlite3_file *id){
+  return SQLITE_DEFAULT_SECTOR_SIZE;
+}
+
+/*
+** Return a vector of device characteristics.
+*/
+static int winDeviceCharacteristics(sqlite3_file *id){
+  return 0;
+}
+
+/*
+** This vector defines all the methods that can operate on an
+** sqlite3_file for win32.
+*/
+static const sqlite3_io_methods winIoMethod = {
+  1,                        /* iVersion */
+  winClose,
+  winRead,
+  winWrite,
+  winTruncate,
+  winSync,
+  winFileSize,
+  winLock,
+  winUnlock,
+  winCheckReservedLock,
+  winFileControl,
+  winSectorSize,
+  winDeviceCharacteristics
+};
+
+/***************************************************************************
+** Here ends the I/O methods that form the sqlite3_io_methods object.
+**
+** The next block of code implements the VFS methods.
+****************************************************************************/
+
+/*
+** Convert a UTF-8 filename into whatever form the underlying
+** operating system wants filenames in.  Space to hold the result
+** is obtained from malloc and must be freed by the calling
+** function.
+*/
+static void *convertUtf8Filename(const char *zFilename){
+  void *zConverted = 0;
+  if( isNT() ){
+    zConverted = utf8ToUnicode(zFilename);
+  }else{
+    zConverted = utf8ToMbcs(zFilename);
+  }
+  /* caller will handle out of memory */
+  return zConverted;
+}
+
+/*
+** Create a temporary file name in zBuf.  zBuf must be big enough to
+** hold at pVfs->mxPathname characters.
+*/
+static int getTempname(int nBuf, char *zBuf){
+  static char zChars[] =
+    "abcdefghijklmnopqrstuvwxyz"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+    "0123456789";
+  size_t i, j;
+  char zTempPath[MAX_PATH+1];
+  if( sqlite3_temp_directory ){
+    sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", sqlite3_temp_directory);
+  }else if( isNT() ){
+    char *zMulti;
+    WCHAR zWidePath[MAX_PATH];
+    GetTempPathW(MAX_PATH-30, zWidePath);
+    zMulti = unicodeToUtf8(zWidePath);
+    if( zMulti ){
+      sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", zMulti);
+      free(zMulti);
+    }else{
+      return SQLITE_NOMEM;
+    }
+  }else{
+    char *zUtf8;
+    char zMbcsPath[MAX_PATH];
+    GetTempPathA(MAX_PATH-30, zMbcsPath);
+    zUtf8 = mbcsToUtf8(zMbcsPath);
+    if( zUtf8 ){
+      sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", zUtf8);
+      free(zUtf8);
+    }else{
+      return SQLITE_NOMEM;
+    }
+  }
+  for(i=strlen(zTempPath); i>0 && zTempPath[i-1]=='\\'; i--){}
+  zTempPath[i] = 0;
+  sqlite3_snprintf(nBuf-30, zBuf,
+                   "%s\\"SQLITE_TEMP_FILE_PREFIX, zTempPath);
+  j = strlen(zBuf);
+  sqlite3_randomness(20, &zBuf[j]);
+  for(i=0; i<20; i++, j++){
+    zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
+  }
+  zBuf[j] = 0;
+  OSTRACE2("TEMP FILENAME: %s\n", zBuf);
+  return SQLITE_OK; 
+}
+
+/*
+** The return value of getLastErrorMsg
+** is zero if the error message fits in the buffer, or non-zero
+** otherwise (if the message was truncated).
+*/
+static int getLastErrorMsg(int nBuf, char *zBuf){
+  DWORD error = GetLastError();
+
+#if SQLITE_OS_WINCE
+  sqlite3_snprintf(nBuf, zBuf, "OsError 0x%x (%u)", error, error);
+#else
+  /* FormatMessage returns 0 on failure.  Otherwise it
+  ** returns the number of TCHARs written to the output
+  ** buffer, excluding the terminating null char.
+  */
+  if (!FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM,
+                      NULL,
+                      error,
+                      0,
+                      zBuf,
+                      nBuf-1,
+                      0))
+  {
+    sqlite3_snprintf(nBuf, zBuf, "OsError 0x%x (%u)", error, error);
+  }
+#endif
+
+  return 0;
+}
+
+
+/*
+** Open a file.
+*/
+static int winOpen(
+  sqlite3_vfs *pVfs,        /* Not used */
+  const char *zName,        /* Name of the file (UTF-8) */
+  sqlite3_file *id,         /* Write the SQLite file handle here */
+  int flags,                /* Open mode flags */
+  int *pOutFlags            /* Status return flags */
+){
+  HANDLE h;
+  DWORD dwDesiredAccess;
+  DWORD dwShareMode;
+  DWORD dwCreationDisposition;
+  DWORD dwFlagsAndAttributes = 0;
+  int isTemp;
+  winFile *pFile = (winFile*)id;
+  void *zConverted;                 /* Filename in OS encoding */
+  const char *zUtf8Name = zName;    /* Filename in UTF-8 encoding */
+  char zTmpname[MAX_PATH+1];        /* Buffer used to create temp filename */
+
+  /* If the second argument to this function is NULL, generate a 
+  ** temporary file name to use 
+  */
+  if( !zUtf8Name ){
+    int rc = getTempname(MAX_PATH+1, zTmpname);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    zUtf8Name = zTmpname;
+  }
+
+  /* Convert the filename to the system encoding. */
+  zConverted = convertUtf8Filename(zUtf8Name);
+  if( zConverted==0 ){
+    return SQLITE_NOMEM;
+  }
+
+  if( flags & SQLITE_OPEN_READWRITE ){
+    dwDesiredAccess = GENERIC_READ | GENERIC_WRITE;
+  }else{
+    dwDesiredAccess = GENERIC_READ;
+  }
+  if( flags & SQLITE_OPEN_CREATE ){
+    dwCreationDisposition = OPEN_ALWAYS;
+  }else{
+    dwCreationDisposition = OPEN_EXISTING;
+  }
+  if( flags & SQLITE_OPEN_MAIN_DB ){
+    dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
+  }else{
+    dwShareMode = 0;
+  }
+  if( flags & SQLITE_OPEN_DELETEONCLOSE ){
+#if SQLITE_OS_WINCE
+    dwFlagsAndAttributes = FILE_ATTRIBUTE_HIDDEN;
+#else
+    dwFlagsAndAttributes = FILE_ATTRIBUTE_TEMPORARY
+                               | FILE_ATTRIBUTE_HIDDEN
+                               | FILE_FLAG_DELETE_ON_CLOSE;
+#endif
+    isTemp = 1;
+  }else{
+    dwFlagsAndAttributes = FILE_ATTRIBUTE_NORMAL;
+    isTemp = 0;
+  }
+  /* Reports from the internet are that performance is always
+  ** better if FILE_FLAG_RANDOM_ACCESS is used.  Ticket #2699. */
+  dwFlagsAndAttributes |= FILE_FLAG_RANDOM_ACCESS;
+  if( isNT() ){
+    h = CreateFileW((WCHAR*)zConverted,
+       dwDesiredAccess,
+       dwShareMode,
+       NULL,
+       dwCreationDisposition,
+       dwFlagsAndAttributes,
+       NULL
+    );
+  }else{
+#if SQLITE_OS_WINCE
+    free(zConverted);
+    return SQLITE_NOMEM;
+#else
+    h = CreateFileA((char*)zConverted,
+       dwDesiredAccess,
+       dwShareMode,
+       NULL,
+       dwCreationDisposition,
+       dwFlagsAndAttributes,
+       NULL
+    );
+#endif
+  }
+  if( h==INVALID_HANDLE_VALUE ){
+    free(zConverted);
+    if( flags & SQLITE_OPEN_READWRITE ){
+      return winOpen(0, zName, id, 
+             ((flags|SQLITE_OPEN_READONLY)&~SQLITE_OPEN_READWRITE), pOutFlags);
+    }else{
+      return SQLITE_CANTOPEN;
+    }
+  }
+  if( pOutFlags ){
+    if( flags & SQLITE_OPEN_READWRITE ){
+      *pOutFlags = SQLITE_OPEN_READWRITE;
+    }else{
+      *pOutFlags = SQLITE_OPEN_READONLY;
+    }
+  }
+  memset(pFile, 0, sizeof(*pFile));
+  pFile->pMethod = &winIoMethod;
+  pFile->h = h;
+#if SQLITE_OS_WINCE
+  if( (flags & (SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_DB)) ==
+               (SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_DB)
+       && !winceCreateLock(zName, pFile)
+  ){
+    CloseHandle(h);
+    free(zConverted);
+    return SQLITE_CANTOPEN;
+  }
+  if( isTemp ){
+    pFile->zDeleteOnClose = zConverted;
+  }else
+#endif
+  {
+    free(zConverted);
+  }
+  OpenCounter(+1);
+  return SQLITE_OK;
+}
+
+/*
+** Delete the named file.
+**
+** Note that windows does not allow a file to be deleted if some other
+** process has it open.  Sometimes a virus scanner or indexing program
+** will open a journal file shortly after it is created in order to do
+** whatever it does.  While this other process is holding the
+** file open, we will be unable to delete it.  To work around this
+** problem, we delay 100 milliseconds and try to delete again.  Up
+** to MX_DELETION_ATTEMPTs deletion attempts are run before giving
+** up and returning an error.
+*/
+#define MX_DELETION_ATTEMPTS 5
+static int winDelete(
+  sqlite3_vfs *pVfs,          /* Not used on win32 */
+  const char *zFilename,      /* Name of file to delete */
+  int syncDir                 /* Not used on win32 */
+){
+  int cnt = 0;
+  int rc;
+  DWORD error;
+  void *zConverted = convertUtf8Filename(zFilename);
+  if( zConverted==0 ){
+    return SQLITE_NOMEM;
+  }
+  SimulateIOError(return SQLITE_IOERR_DELETE);
+  if( isNT() ){
+    do{
+      DeleteFileW(zConverted);
+    }while(   (   ((rc = GetFileAttributesW(zConverted)) != INVALID_FILE_ATTRIBUTES)
+               || ((error = GetLastError()) == ERROR_ACCESS_DENIED))
+           && (cnt++ < MX_DELETION_ATTEMPTS)
+           && (Sleep(100), 1) );
+  }else{
+#if SQLITE_OS_WINCE
+    free(zConverted);
+    return SQLITE_NOMEM;
+#else
+    do{
+      DeleteFileA(zConverted);
+    }while(   (   ((rc = GetFileAttributesA(zConverted)) != INVALID_FILE_ATTRIBUTES)
+               || ((error = GetLastError()) == ERROR_ACCESS_DENIED))
+           && (cnt++ < MX_DELETION_ATTEMPTS)
+           && (Sleep(100), 1) );
+#endif
+  }
+  free(zConverted);
+  OSTRACE2("DELETE \"%s\"\n", zFilename);
+  return (   (rc==INVALID_FILE_ATTRIBUTES) 
+          && (error == ERROR_FILE_NOT_FOUND)) ? SQLITE_OK : SQLITE_IOERR_DELETE;
+}
+
+/*
+** Check the existance and status of a file.
+*/
+static int winAccess(
+  sqlite3_vfs *pVfs,         /* Not used on win32 */
+  const char *zFilename,     /* Name of file to check */
+  int flags,                 /* Type of test to make on this file */
+  int *pResOut               /* OUT: Result */
+){
+  DWORD attr;
+  int rc;
+  void *zConverted = convertUtf8Filename(zFilename);
+  if( zConverted==0 ){
+    return SQLITE_NOMEM;
+  }
+  if( isNT() ){
+    attr = GetFileAttributesW((WCHAR*)zConverted);
+  }else{
+#if SQLITE_OS_WINCE
+    free(zConverted);
+    return SQLITE_NOMEM;
+#else
+    attr = GetFileAttributesA((char*)zConverted);
+#endif
+  }
+  free(zConverted);
+  switch( flags ){
+    case SQLITE_ACCESS_READ:
+    case SQLITE_ACCESS_EXISTS:
+      rc = attr!=INVALID_FILE_ATTRIBUTES;
+      break;
+    case SQLITE_ACCESS_READWRITE:
+      rc = (attr & FILE_ATTRIBUTE_READONLY)==0;
+      break;
+    default:
+      assert(!"Invalid flags argument");
+  }
+  *pResOut = rc;
+  return SQLITE_OK;
+}
+
+
+/*
+** Turn a relative pathname into a full pathname.  Write the full
+** pathname into zOut[].  zOut[] will be at least pVfs->mxPathname
+** bytes in size.
+*/
+static int winFullPathname(
+  sqlite3_vfs *pVfs,            /* Pointer to vfs object */
+  const char *zRelative,        /* Possibly relative input path */
+  int nFull,                    /* Size of output buffer in bytes */
+  char *zFull                   /* Output buffer */
+){
+
+#if defined(__CYGWIN__)
+  cygwin_conv_to_full_win32_path(zRelative, zFull);
+  return SQLITE_OK;
+#endif
+
+#if SQLITE_OS_WINCE
+  /* WinCE has no concept of a relative pathname, or so I am told. */
+  sqlite3_snprintf(pVfs->mxPathname, zFull, "%s", zRelative);
+  return SQLITE_OK;
+#endif
+
+#if !SQLITE_OS_WINCE && !defined(__CYGWIN__)
+  int nByte;
+  void *zConverted;
+  char *zOut;
+  zConverted = convertUtf8Filename(zRelative);
+  if( isNT() ){
+    WCHAR *zTemp;
+    nByte = GetFullPathNameW((WCHAR*)zConverted, 0, 0, 0) + 3;
+    zTemp = malloc( nByte*sizeof(zTemp[0]) );
+    if( zTemp==0 ){
+      free(zConverted);
+      return SQLITE_NOMEM;
+    }
+    GetFullPathNameW((WCHAR*)zConverted, nByte, zTemp, 0);
+    free(zConverted);
+    zOut = unicodeToUtf8(zTemp);
+    free(zTemp);
+  }else{
+    char *zTemp;
+    nByte = GetFullPathNameA((char*)zConverted, 0, 0, 0) + 3;
+    zTemp = malloc( nByte*sizeof(zTemp[0]) );
+    if( zTemp==0 ){
+      free(zConverted);
+      return SQLITE_NOMEM;
+    }
+    GetFullPathNameA((char*)zConverted, nByte, zTemp, 0);
+    free(zConverted);
+    zOut = mbcsToUtf8(zTemp);
+    free(zTemp);
+  }
+  if( zOut ){
+    sqlite3_snprintf(pVfs->mxPathname, zFull, "%s", zOut);
+    free(zOut);
+    return SQLITE_OK;
+  }else{
+    return SQLITE_NOMEM;
+  }
+#endif
+}
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+/*
+** Interfaces for opening a shared library, finding entry points
+** within the shared library, and closing the shared library.
+*/
+/*
+** Interfaces for opening a shared library, finding entry points
+** within the shared library, and closing the shared library.
+*/
+static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
+  HANDLE h;
+  void *zConverted = convertUtf8Filename(zFilename);
+  if( zConverted==0 ){
+    return 0;
+  }
+  if( isNT() ){
+    h = LoadLibraryW((WCHAR*)zConverted);
+  }else{
+    h = LoadLibraryA((char*)zConverted);
+  }
+  free(zConverted);
+  return (void*)h;
+}
+static void winDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
+  getLastErrorMsg(nBuf, zBufOut);
+}
+void *winDlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol){
+#if SQLITE_OS_WINCE
+  /* The GetProcAddressA() routine is only available on wince. */
+  return GetProcAddressA((HANDLE)pHandle, zSymbol);
+#else
+  /* All other windows platforms expect GetProcAddress() to take
+  ** an Ansi string regardless of the _UNICODE setting */
+  return GetProcAddress((HANDLE)pHandle, zSymbol);
+#endif
+}
+void winDlClose(sqlite3_vfs *pVfs, void *pHandle){
+  FreeLibrary((HANDLE)pHandle);
+}
+#else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
+  #define winDlOpen  0
+  #define winDlError 0
+  #define winDlSym   0
+  #define winDlClose 0
+#endif
+
+
+/*
+** Write up to nBuf bytes of randomness into zBuf.
+*/
+static int winRandomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
+  int n = 0;
+  if( sizeof(SYSTEMTIME)<=nBuf-n ){
+    SYSTEMTIME x;
+    GetSystemTime(&x);
+    memcpy(&zBuf[n], &x, sizeof(x));
+    n += sizeof(x);
+  }
+  if( sizeof(DWORD)<=nBuf-n ){
+    DWORD pid = GetCurrentProcessId();
+    memcpy(&zBuf[n], &pid, sizeof(pid));
+    n += sizeof(pid);
+  }
+  if( sizeof(DWORD)<=nBuf-n ){
+    DWORD cnt = GetTickCount();
+    memcpy(&zBuf[n], &cnt, sizeof(cnt));
+    n += sizeof(cnt);
+  }
+  if( sizeof(LARGE_INTEGER)<=nBuf-n ){
+    LARGE_INTEGER i;
+    QueryPerformanceCounter(&i);
+    memcpy(&zBuf[n], &i, sizeof(i));
+    n += sizeof(i);
+  }
+  return n;
+}
+
+
+/*
+** Sleep for a little while.  Return the amount of time slept.
+*/
+static int winSleep(sqlite3_vfs *pVfs, int microsec){
+  Sleep((microsec+999)/1000);
+  return ((microsec+999)/1000)*1000;
+}
+
+/*
+** The following variable, if set to a non-zero value, becomes the result
+** returned from sqlite3OsCurrentTime().  This is used for testing.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_current_time = 0;
+#endif
+
+/*
+** Find the current time (in Universal Coordinated Time).  Write the
+** current time and date as a Julian Day number into *prNow and
+** return 0.  Return 1 if the time and date cannot be found.
+*/
+int winCurrentTime(sqlite3_vfs *pVfs, double *prNow){
+  FILETIME ft;
+  /* FILETIME structure is a 64-bit value representing the number of 
+     100-nanosecond intervals since January 1, 1601 (= JD 2305813.5). 
+  */
+  double now;
+#if SQLITE_OS_WINCE
+  SYSTEMTIME time;
+  GetSystemTime(&time);
+  /* if SystemTimeToFileTime() fails, it returns zero. */
+  if (!SystemTimeToFileTime(&time,&ft)){
+    return 1;
+  }
+#else
+  GetSystemTimeAsFileTime( &ft );
+#endif
+  now = ((double)ft.dwHighDateTime) * 4294967296.0; 
+  *prNow = (now + ft.dwLowDateTime)/864000000000.0 + 2305813.5;
+#ifdef SQLITE_TEST
+  if( sqlite3_current_time ){
+    *prNow = sqlite3_current_time/86400.0 + 2440587.5;
+  }
+#endif
+  return 0;
+}
+
+/*
+** The idea is that this function works like a combination of
+** GetLastError() and FormatMessage() on windows (or errno and
+** strerror_r() on unix). After an error is returned by an OS
+** function, SQLite calls this function with zBuf pointing to
+** a buffer of nBuf bytes. The OS layer should populate the
+** buffer with a nul-terminated UTF-8 encoded error message
+** describing the last IO error to have occured within the calling
+** thread.
+**
+** If the error message is too large for the supplied buffer,
+** it should be truncated. The return value of xGetLastError
+** is zero if the error message fits in the buffer, or non-zero
+** otherwise (if the message was truncated). If non-zero is returned,
+** then it is not necessary to include the nul-terminator character
+** in the output buffer.
+**
+** Not supplying an error message will have no adverse effect
+** on SQLite. It is fine to have an implementation that never
+** returns an error message:
+**
+**   int xGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
+**     assert(zBuf[0]=='\0');
+**     return 0;
+**   }
+**
+** However if an error message is supplied, it will be incorporated
+** by sqlite into the error message available to the user using
+** sqlite3_errmsg(), possibly making IO errors easier to debug.
+*/
+static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
+  return getLastErrorMsg(nBuf, zBuf);
+}
+
+/*
+** Initialize and deinitialize the operating system interface.
+*/
+int sqlite3_os_init(void){
+  static sqlite3_vfs winVfs = {
+    1,                 /* iVersion */
+    sizeof(winFile),   /* szOsFile */
+    MAX_PATH,          /* mxPathname */
+    0,                 /* pNext */
+    "win32",           /* zName */
+    0,                 /* pAppData */
+ 
+    winOpen,           /* xOpen */
+    winDelete,         /* xDelete */
+    winAccess,         /* xAccess */
+    winFullPathname,   /* xFullPathname */
+    winDlOpen,         /* xDlOpen */
+    winDlError,        /* xDlError */
+    winDlSym,          /* xDlSym */
+    winDlClose,        /* xDlClose */
+    winRandomness,     /* xRandomness */
+    winSleep,          /* xSleep */
+    winCurrentTime,    /* xCurrentTime */
+    winGetLastError    /* xGetLastError */
+  };
+  sqlite3_vfs_register(&winVfs, 1);
+  return SQLITE_OK; 
+}
+int sqlite3_os_end(void){ 
+  return SQLITE_OK;
+}
+
+#endif /* SQLITE_OS_WIN */
diff --git a/third_party/sqlite/src/pager.c b/third_party/sqlite/src/pager.c
new file mode 100755
index 0000000..b9f50a4
--- /dev/null
+++ b/third_party/sqlite/src/pager.c
@@ -0,0 +1,5494 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This is the implementation of the page cache subsystem or "pager".
+** 
+** The pager is used to access a database disk file.  It implements
+** atomic commit and rollback through the use of a journal file that
+** is separate from the database file.  The pager also implements file
+** locking to prevent two processes from writing the same database
+** file simultaneously, or one process from reading the database while
+** another is writing.
+**
+** @(#) $Id: pager.c,v 1.469 2008/08/02 03:50:39 drh Exp $
+*/
+#ifndef SQLITE_OMIT_DISKIO
+#include "sqliteInt.h"
+#include <assert.h>
+#include <string.h>
+
+/*
+** Macros for troubleshooting.  Normally turned off
+*/
+#if 0
+#define sqlite3DebugPrintf printf
+#define PAGERTRACE1(X)       sqlite3DebugPrintf(X)
+#define PAGERTRACE2(X,Y)     sqlite3DebugPrintf(X,Y)
+#define PAGERTRACE3(X,Y,Z)   sqlite3DebugPrintf(X,Y,Z)
+#define PAGERTRACE4(X,Y,Z,W) sqlite3DebugPrintf(X,Y,Z,W)
+#define PAGERTRACE5(X,Y,Z,W,V) sqlite3DebugPrintf(X,Y,Z,W,V)
+#else
+#define PAGERTRACE1(X)
+#define PAGERTRACE2(X,Y)
+#define PAGERTRACE3(X,Y,Z)
+#define PAGERTRACE4(X,Y,Z,W)
+#define PAGERTRACE5(X,Y,Z,W,V)
+#endif
+
+/*
+** The following two macros are used within the PAGERTRACEX() macros above
+** to print out file-descriptors. 
+**
+** PAGERID() takes a pointer to a Pager struct as its argument. The
+** associated file-descriptor is returned. FILEHANDLEID() takes an sqlite3_file
+** struct as its argument.
+*/
+#define PAGERID(p) ((int)(p->fd))
+#define FILEHANDLEID(fd) ((int)fd)
+
+/*
+** The page cache as a whole is always in one of the following
+** states:
+**
+**   PAGER_UNLOCK        The page cache is not currently reading or 
+**                       writing the database file.  There is no
+**                       data held in memory.  This is the initial
+**                       state.
+**
+**   PAGER_SHARED        The page cache is reading the database.
+**                       Writing is not permitted.  There can be
+**                       multiple readers accessing the same database
+**                       file at the same time.
+**
+**   PAGER_RESERVED      This process has reserved the database for writing
+**                       but has not yet made any changes.  Only one process
+**                       at a time can reserve the database.  The original
+**                       database file has not been modified so other
+**                       processes may still be reading the on-disk
+**                       database file.
+**
+**   PAGER_EXCLUSIVE     The page cache is writing the database.
+**                       Access is exclusive.  No other processes or
+**                       threads can be reading or writing while one
+**                       process is writing.
+**
+**   PAGER_SYNCED        The pager moves to this state from PAGER_EXCLUSIVE
+**                       after all dirty pages have been written to the
+**                       database file and the file has been synced to
+**                       disk. All that remains to do is to remove or
+**                       truncate the journal file and the transaction 
+**                       will be committed.
+**
+** The page cache comes up in PAGER_UNLOCK.  The first time a
+** sqlite3PagerGet() occurs, the state transitions to PAGER_SHARED.
+** After all pages have been released using sqlite_page_unref(),
+** the state transitions back to PAGER_UNLOCK.  The first time
+** that sqlite3PagerWrite() is called, the state transitions to
+** PAGER_RESERVED.  (Note that sqlite3PagerWrite() can only be
+** called on an outstanding page which means that the pager must
+** be in PAGER_SHARED before it transitions to PAGER_RESERVED.)
+** PAGER_RESERVED means that there is an open rollback journal.
+** The transition to PAGER_EXCLUSIVE occurs before any changes
+** are made to the database file, though writes to the rollback
+** journal occurs with just PAGER_RESERVED.  After an sqlite3PagerRollback()
+** or sqlite3PagerCommitPhaseTwo(), the state can go back to PAGER_SHARED,
+** or it can stay at PAGER_EXCLUSIVE if we are in exclusive access mode.
+*/
+#define PAGER_UNLOCK      0
+#define PAGER_SHARED      1   /* same as SHARED_LOCK */
+#define PAGER_RESERVED    2   /* same as RESERVED_LOCK */
+#define PAGER_EXCLUSIVE   4   /* same as EXCLUSIVE_LOCK */
+#define PAGER_SYNCED      5
+
+/*
+** If the SQLITE_BUSY_RESERVED_LOCK macro is set to true at compile-time,
+** then failed attempts to get a reserved lock will invoke the busy callback.
+** This is off by default.  To see why, consider the following scenario:
+** 
+** Suppose thread A already has a shared lock and wants a reserved lock.
+** Thread B already has a reserved lock and wants an exclusive lock.  If
+** both threads are using their busy callbacks, it might be a long time
+** be for one of the threads give up and allows the other to proceed.
+** But if the thread trying to get the reserved lock gives up quickly
+** (if it never invokes its busy callback) then the contention will be
+** resolved quickly.
+*/
+#ifndef SQLITE_BUSY_RESERVED_LOCK
+# define SQLITE_BUSY_RESERVED_LOCK 0
+#endif
+
+/*
+** This macro rounds values up so that if the value is an address it
+** is guaranteed to be an address that is aligned to an 8-byte boundary.
+*/
+#define FORCE_ALIGNMENT(X)   (((X)+7)&~7)
+
+typedef struct PgHdr PgHdr;
+
+/*
+** Each pager stores all currently unreferenced pages in a list sorted
+** in least-recently-used (LRU) order (i.e. the first item on the list has 
+** not been referenced in a long time, the last item has been recently
+** used). An instance of this structure is included as part of each
+** pager structure for this purpose (variable Pager.lru).
+**
+** Additionally, if memory-management is enabled, all unreferenced pages 
+** are stored in a global LRU list (global variable sqlite3LruPageList).
+**
+** In both cases, the PagerLruList.pFirstSynced variable points to
+** the first page in the corresponding list that does not require an
+** fsync() operation before its memory can be reclaimed. If no such
+** page exists, PagerLruList.pFirstSynced is set to NULL.
+*/
+typedef struct PagerLruList PagerLruList;
+struct PagerLruList {
+  PgHdr *pFirst;         /* First page in LRU list */
+  PgHdr *pLast;          /* Last page in LRU list (the most recently used) */
+  PgHdr *pFirstSynced;   /* First page in list with PgHdr.needSync==0 */
+};
+
+/*
+** The following structure contains the next and previous pointers used
+** to link a PgHdr structure into a PagerLruList linked list. 
+*/
+typedef struct PagerLruLink PagerLruLink;
+struct PagerLruLink {
+  PgHdr *pNext;
+  PgHdr *pPrev;
+};
+
+/*
+** Each in-memory image of a page begins with the following header.
+** This header is only visible to this pager module.  The client
+** code that calls pager sees only the data that follows the header.
+**
+** Client code should call sqlite3PagerWrite() on a page prior to making
+** any modifications to that page.  The first time sqlite3PagerWrite()
+** is called, the original page contents are written into the rollback
+** journal and PgHdr.inJournal and PgHdr.needSync are set.  Later, once
+** the journal page has made it onto the disk surface, PgHdr.needSync
+** is cleared.  The modified page cannot be written back into the original
+** database file until the journal pages has been synced to disk and the
+** PgHdr.needSync has been cleared.
+**
+** The PgHdr.dirty flag is set when sqlite3PagerWrite() is called and
+** is cleared again when the page content is written back to the original
+** database file.
+**
+** Details of important structure elements:
+**
+** needSync
+**
+**     If this is true, this means that it is not safe to write the page
+**     content to the database because the original content needed
+**     for rollback has not by synced to the main rollback journal.
+**     The original content may have been written to the rollback journal
+**     but it has not yet been synced.  So we cannot write to the database
+**     file because power failure might cause the page in the journal file
+**     to never reach the disk.  It is as if the write to the journal file
+**     does not occur until the journal file is synced.
+**     
+**     This flag is false if the page content exactly matches what
+**     currently exists in the database file.  The needSync flag is also
+**     false if the original content has been written to the main rollback
+**     journal and synced.  If the page represents a new page that has
+**     been added onto the end of the database during the current
+**     transaction, the needSync flag is true until the original database
+**     size in the journal header has been synced to disk.
+**
+** inJournal
+**
+**     This is true if the original page has been written into the main
+**     rollback journal.  This is always false for new pages added to
+**     the end of the database file during the current transaction.
+**     And this flag says nothing about whether or not the journal
+**     has been synced to disk.  For pages that are in the original
+**     database file, the following expression should always be true:
+**
+**       inJournal = sqlite3BitvecTest(pPager->pInJournal, pgno)
+**
+**     The pPager->pInJournal object is only valid for the original
+**     pages of the database, not new pages that are added to the end
+**     of the database, so obviously the above expression cannot be
+**     valid for new pages.  For new pages inJournal is always 0.
+**
+** dirty
+**
+**     When true, this means that the content of the page has been
+**     modified and needs to be written back to the database file.
+**     If false, it means that either the content of the page is
+**     unchanged or else the content is unimportant and we do not
+**     care whether or not it is preserved.
+**
+** alwaysRollback
+**
+**     This means that the sqlite3PagerDontRollback() API should be
+**     ignored for this page.  The DontRollback() API attempts to say
+**     that the content of the page on disk is unimportant (it is an
+**     unused page on the freelist) so that it is unnecessary to 
+**     rollback changes to this page because the content of the page
+**     can change without changing the meaning of the database.  This
+**     flag overrides any DontRollback() attempt.  This flag is set
+**     when a page that originally contained valid data is added to
+**     the freelist.  Later in the same transaction, this page might
+**     be pulled from the freelist and reused for something different
+**     and at that point the DontRollback() API will be called because
+**     pages taken from the freelist do not need to be protected by
+**     the rollback journal.  But this flag says that the page was
+**     not originally part of the freelist so that it still needs to
+**     be rolled back in spite of any subsequent DontRollback() calls.
+**
+** needRead 
+**
+**     This flag means (when true) that the content of the page has
+**     not yet been loaded from disk.  The in-memory content is just
+**     garbage.  (Actually, we zero the content, but you should not
+**     make any assumptions about the content nevertheless.)  If the
+**     content is needed in the future, it should be read from the
+**     original database file.
+*/
+struct PgHdr {
+  Pager *pPager;                 /* The pager to which this page belongs */
+  Pgno pgno;                     /* The page number for this page */
+  PgHdr *pNextHash, *pPrevHash;  /* Hash collision chain for PgHdr.pgno */
+  PagerLruLink free;             /* Next and previous free pages */
+  PgHdr *pNextAll;               /* A list of all pages */
+  u8 inJournal;                  /* TRUE if has been written to journal */
+  u8 dirty;                      /* TRUE if we need to write back changes */
+  u8 needSync;                   /* Sync journal before writing this page */
+  u8 alwaysRollback;             /* Disable DontRollback() for this page */
+  u8 needRead;                   /* Read content if PagerWrite() is called */
+  short int nRef;                /* Number of users of this page */
+  PgHdr *pDirty, *pPrevDirty;    /* Dirty pages */
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  PgHdr *pPrevAll;               /* A list of all pages */
+  PagerLruLink gfree;            /* Global list of nRef==0 pages */
+#endif
+#ifdef SQLITE_CHECK_PAGES
+  u32 pageHash;
+#endif
+  void *pData;                   /* Page data */
+  /* Pager.nExtra bytes of local data appended to this header */
+};
+
+/*
+** For an in-memory only database, some extra information is recorded about
+** each page so that changes can be rolled back.  (Journal files are not
+** used for in-memory databases.)  The following information is added to
+** the end of every EXTRA block for in-memory databases.
+**
+** This information could have been added directly to the PgHdr structure.
+** But then it would take up an extra 8 bytes of storage on every PgHdr
+** even for disk-based databases.  Splitting it out saves 8 bytes.  This
+** is only a savings of 0.8% but those percentages add up.
+*/
+typedef struct PgHistory PgHistory;
+struct PgHistory {
+  u8 *pOrig;     /* Original page text.  Restore to this on a full rollback */
+  u8 *pStmt;     /* Text as it was at the beginning of the current statement */
+  PgHdr *pNextStmt, *pPrevStmt;  /* List of pages in the statement journal */
+  u8 inStmt;                     /* TRUE if in the statement subjournal */
+};
+
+/*
+** A macro used for invoking the codec if there is one
+*/
+#ifdef SQLITE_HAS_CODEC
+# define CODEC1(P,D,N,X) if( P->xCodec!=0 ){ P->xCodec(P->pCodecArg,D,N,X); }
+# define CODEC2(P,D,N,X) ((char*)(P->xCodec!=0?P->xCodec(P->pCodecArg,D,N,X):D))
+#else
+# define CODEC1(P,D,N,X) /* NO-OP */
+# define CODEC2(P,D,N,X) ((char*)D)
+#endif
+
+/*
+** Convert a pointer to a PgHdr into a pointer to its data
+** and back again.
+*/
+#define PGHDR_TO_DATA(P)    ((P)->pData)
+#define PGHDR_TO_EXTRA(G,P) ((void*)&((G)[1]))
+#define PGHDR_TO_HIST(P,PGR)  \
+            ((PgHistory*)&((char*)(&(P)[1]))[(PGR)->nExtra])
+
+/*
+** A open page cache is an instance of the following structure.
+**
+** Pager.errCode may be set to SQLITE_IOERR, SQLITE_CORRUPT, or
+** or SQLITE_FULL. Once one of the first three errors occurs, it persists
+** and is returned as the result of every major pager API call.  The
+** SQLITE_FULL return code is slightly different. It persists only until the
+** next successful rollback is performed on the pager cache. Also,
+** SQLITE_FULL does not affect the sqlite3PagerGet() and sqlite3PagerLookup()
+** APIs, they may still be used successfully.
+*/
+struct Pager {
+  sqlite3_vfs *pVfs;          /* OS functions to use for IO */
+  u8 journalOpen;             /* True if journal file descriptors is valid */
+  u8 journalStarted;          /* True if header of journal is synced */
+  u8 useJournal;              /* Use a rollback journal on this file */
+  u8 noReadlock;              /* Do not bother to obtain readlocks */
+  u8 stmtOpen;                /* True if the statement subjournal is open */
+  u8 stmtInUse;               /* True we are in a statement subtransaction */
+  u8 stmtAutoopen;            /* Open stmt journal when main journal is opened*/
+  u8 noSync;                  /* Do not sync the journal if true */
+  u8 fullSync;                /* Do extra syncs of the journal for robustness */
+  u8 sync_flags;              /* One of SYNC_NORMAL or SYNC_FULL */
+  u8 state;                   /* PAGER_UNLOCK, _SHARED, _RESERVED, etc. */
+  u8 tempFile;                /* zFilename is a temporary file */
+  u8 readOnly;                /* True for a read-only database */
+  u8 needSync;                /* True if an fsync() is needed on the journal */
+  u8 dirtyCache;              /* True if cached pages have changed */
+  u8 alwaysRollback;          /* Disable DontRollback() for all pages */
+  u8 memDb;                   /* True to inhibit all file I/O */
+  u8 setMaster;               /* True if a m-j name has been written to jrnl */
+  u8 doNotSync;               /* Boolean. While true, do not spill the cache */
+  u8 exclusiveMode;           /* Boolean. True if locking_mode==EXCLUSIVE */
+  u8 journalMode;             /* On of the PAGER_JOURNALMODE_* values */
+  u8 dbModified;              /* True if there are any changes to the Db */
+  u8 changeCountDone;         /* Set after incrementing the change-counter */
+  u32 vfsFlags;               /* Flags for sqlite3_vfs.xOpen() */
+  int errCode;                /* One of several kinds of errors */
+  int dbSize;                 /* Number of pages in the file */
+  int origDbSize;             /* dbSize before the current change */
+  int stmtSize;               /* Size of database (in pages) at stmt_begin() */
+  int nRec;                   /* Number of pages written to the journal */
+  u32 cksumInit;              /* Quasi-random value added to every checksum */
+  int stmtNRec;               /* Number of records in stmt subjournal */
+  int nExtra;                 /* Add this many bytes to each in-memory page */
+  int pageSize;               /* Number of bytes in a page */
+  int nPage;                  /* Total number of in-memory pages */
+  int nRef;                   /* Number of in-memory pages with PgHdr.nRef>0 */
+  int mxPage;                 /* Maximum number of pages to hold in cache */
+  Pgno mxPgno;                /* Maximum allowed size of the database */
+  Bitvec *pInJournal;         /* One bit for each page in the database file */
+  Bitvec *pInStmt;            /* One bit for each page in the database */
+  char *zFilename;            /* Name of the database file */
+  char *zJournal;             /* Name of the journal file */
+  char *zDirectory;           /* Directory hold database and journal files */
+  sqlite3_file *fd, *jfd;     /* File descriptors for database and journal */
+  sqlite3_file *stfd;         /* File descriptor for the statement subjournal*/
+  BusyHandler *pBusyHandler;  /* Pointer to sqlite.busyHandler */
+  PagerLruList lru;           /* LRU list of free pages */
+  PgHdr *pAll;                /* List of all pages */
+  PgHdr *pStmt;               /* List of pages in the statement subjournal */
+  PgHdr *pDirty;              /* List of all dirty pages */
+  i64 journalOff;             /* Current byte offset in the journal file */
+  i64 journalHdr;             /* Byte offset to previous journal header */
+  i64 stmtHdrOff;             /* First journal header written this statement */
+  i64 stmtCksum;              /* cksumInit when statement was started */
+  i64 stmtJSize;              /* Size of journal at stmt_begin() */
+  int sectorSize;             /* Assumed sector size during rollback */
+#ifdef SQLITE_TEST
+  int nHit, nMiss;            /* Cache hits and missing */
+  int nRead, nWrite;          /* Database pages read/written */
+#endif
+  void (*xDestructor)(DbPage*,int); /* Call this routine when freeing pages */
+  void (*xReiniter)(DbPage*,int);   /* Call this routine when reloading pages */
+#ifdef SQLITE_HAS_CODEC
+  void *(*xCodec)(void*,void*,Pgno,int); /* Routine for en/decoding data */
+  void *pCodecArg;            /* First argument to xCodec() */
+#endif
+  int nHash;                  /* Size of the pager hash table */
+  PgHdr **aHash;              /* Hash table to map page number to PgHdr */
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  Pager *pNext;               /* Doubly linked list of pagers on which */
+  Pager *pPrev;               /* sqlite3_release_memory() will work */
+  volatile int iInUseMM;      /* Non-zero if unavailable to MM */
+  volatile int iInUseDB;      /* Non-zero if in sqlite3_release_memory() */
+#endif
+  char *pTmpSpace;            /* Pager.pageSize bytes of space for tmp use */
+  char dbFileVers[16];        /* Changes whenever database file changes */
+  i64 journalSizeLimit;       /* Size limit for persistent journal files */
+};
+
+/*
+** The following global variables hold counters used for
+** testing purposes only.  These variables do not exist in
+** a non-testing build.  These variables are not thread-safe.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_pager_readdb_count = 0;    /* Number of full pages read from DB */
+int sqlite3_pager_writedb_count = 0;   /* Number of full pages written to DB */
+int sqlite3_pager_writej_count = 0;    /* Number of pages written to journal */
+int sqlite3_pager_pgfree_count = 0;    /* Number of cache pages freed */
+# define PAGER_INCR(v)  v++
+#else
+# define PAGER_INCR(v)
+#endif
+
+/*
+** The following variable points to the head of a double-linked list
+** of all pagers that are eligible for page stealing by the
+** sqlite3_release_memory() interface.  Access to this list is
+** protected by the SQLITE_MUTEX_STATIC_MEM2 mutex.
+*/
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+static Pager *sqlite3PagerList = 0;
+static PagerLruList sqlite3LruPageList = {0, 0, 0};
+#endif
+
+
+/*
+** Journal files begin with the following magic string.  The data
+** was obtained from /dev/random.  It is used only as a sanity check.
+**
+** Since version 2.8.0, the journal format contains additional sanity
+** checking information.  If the power fails while the journal is begin
+** written, semi-random garbage data might appear in the journal
+** file after power is restored.  If an attempt is then made
+** to roll the journal back, the database could be corrupted.  The additional
+** sanity checking data is an attempt to discover the garbage in the
+** journal and ignore it.
+**
+** The sanity checking information for the new journal format consists
+** of a 32-bit checksum on each page of data.  The checksum covers both
+** the page number and the pPager->pageSize bytes of data for the page.
+** This cksum is initialized to a 32-bit random value that appears in the
+** journal file right after the header.  The random initializer is important,
+** because garbage data that appears at the end of a journal is likely
+** data that was once in other files that have now been deleted.  If the
+** garbage data came from an obsolete journal file, the checksums might
+** be correct.  But by initializing the checksum to random value which
+** is different for every journal, we minimize that risk.
+*/
+static const unsigned char aJournalMagic[] = {
+  0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd7,
+};
+
+/*
+** The size of the header and of each page in the journal is determined
+** by the following macros.
+*/
+#define JOURNAL_PG_SZ(pPager)  ((pPager->pageSize) + 8)
+
+/*
+** The journal header size for this pager. In the future, this could be
+** set to some value read from the disk controller. The important
+** characteristic is that it is the same size as a disk sector.
+*/
+#define JOURNAL_HDR_SZ(pPager) (pPager->sectorSize)
+
+/*
+** The macro MEMDB is true if we are dealing with an in-memory database.
+** We do this as a macro so that if the SQLITE_OMIT_MEMORYDB macro is set,
+** the value of MEMDB will be a constant and the compiler will optimize
+** out code that would never execute.
+*/
+#ifdef SQLITE_OMIT_MEMORYDB
+# define MEMDB 0
+#else
+# define MEMDB pPager->memDb
+#endif
+
+/*
+** Page number PAGER_MJ_PGNO is never used in an SQLite database (it is
+** reserved for working around a windows/posix incompatibility). It is
+** used in the journal to signify that the remainder of the journal file 
+** is devoted to storing a master journal name - there are no more pages to
+** roll back. See comments for function writeMasterJournal() for details.
+*/
+/* #define PAGER_MJ_PGNO(x) (PENDING_BYTE/((x)->pageSize)) */
+#define PAGER_MJ_PGNO(x) ((PENDING_BYTE/((x)->pageSize))+1)
+
+/*
+** The maximum legal page number is (2^31 - 1).
+*/
+#define PAGER_MAX_PGNO 2147483647
+
+/* Begin preload-cache.patch for Chromium */
+/* See comments above the definition. */
+int sqlite3PagerAcquire2(
+  Pager *pPager,
+  Pgno pgno,
+  DbPage **ppPage,
+  int noContent,
+  unsigned char *pDataToFill);
+/* End preload-cache.patch for Chromium */
+
+/*
+** The pagerEnter() and pagerLeave() routines acquire and release
+** a mutex on each pager.  The mutex is recursive.
+**
+** This is a special-purpose mutex.  It only provides mutual exclusion
+** between the Btree and the Memory Management sqlite3_release_memory()
+** function.  It does not prevent, for example, two Btrees from accessing
+** the same pager at the same time.  Other general-purpose mutexes in
+** the btree layer handle that chore.
+*/
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  static void pagerEnter(Pager *p){
+    p->iInUseDB++;
+    if( p->iInUseMM && p->iInUseDB==1 ){
+#ifndef SQLITE_MUTEX_NOOP
+      sqlite3_mutex *mutex;
+      mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM2);
+#endif
+      p->iInUseDB = 0;
+      sqlite3_mutex_enter(mutex);
+      p->iInUseDB = 1;
+      sqlite3_mutex_leave(mutex);
+    }
+    assert( p->iInUseMM==0 );
+  }
+  static void pagerLeave(Pager *p){
+    p->iInUseDB--;
+    assert( p->iInUseDB>=0 );
+  }
+#else
+# define pagerEnter(X)
+# define pagerLeave(X)
+#endif
+
+/*
+** Add page pPg to the end of the linked list managed by structure
+** pList (pPg becomes the last entry in the list - the most recently 
+** used). Argument pLink should point to either pPg->free or pPg->gfree,
+** depending on whether pPg is being added to the pager-specific or
+** global LRU list.
+*/
+static void listAdd(PagerLruList *pList, PagerLruLink *pLink, PgHdr *pPg){
+  pLink->pNext = 0;
+  pLink->pPrev = pList->pLast;
+
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  assert(pLink==&pPg->free || pLink==&pPg->gfree);
+  assert(pLink==&pPg->gfree || pList!=&sqlite3LruPageList);
+#endif
+
+  if( pList->pLast ){
+    int iOff = (char *)pLink - (char *)pPg;
+    PagerLruLink *pLastLink = (PagerLruLink *)(&((u8 *)pList->pLast)[iOff]);
+    pLastLink->pNext = pPg;
+  }else{
+    assert(!pList->pFirst);
+    pList->pFirst = pPg;
+  }
+
+  pList->pLast = pPg;
+  if( !pList->pFirstSynced && pPg->needSync==0 ){
+    pList->pFirstSynced = pPg;
+  }
+}
+
+/*
+** Remove pPg from the list managed by the structure pointed to by pList.
+**
+** Argument pLink should point to either pPg->free or pPg->gfree, depending 
+** on whether pPg is being added to the pager-specific or global LRU list.
+*/
+static void listRemove(PagerLruList *pList, PagerLruLink *pLink, PgHdr *pPg){
+  int iOff = (char *)pLink - (char *)pPg;
+
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  assert(pLink==&pPg->free || pLink==&pPg->gfree);
+  assert(pLink==&pPg->gfree || pList!=&sqlite3LruPageList);
+#endif
+
+  if( pPg==pList->pFirst ){
+    pList->pFirst = pLink->pNext;
+  }
+  if( pPg==pList->pLast ){
+    pList->pLast = pLink->pPrev;
+  }
+  if( pLink->pPrev ){
+    PagerLruLink *pPrevLink = (PagerLruLink *)(&((u8 *)pLink->pPrev)[iOff]);
+    pPrevLink->pNext = pLink->pNext;
+  }
+  if( pLink->pNext ){
+    PagerLruLink *pNextLink = (PagerLruLink *)(&((u8 *)pLink->pNext)[iOff]);
+    pNextLink->pPrev = pLink->pPrev;
+  }
+  if( pPg==pList->pFirstSynced ){
+    PgHdr *p = pLink->pNext;
+    while( p && p->needSync ){
+      PagerLruLink *pL = (PagerLruLink *)(&((u8 *)p)[iOff]);
+      p = pL->pNext;
+    }
+    pList->pFirstSynced = p;
+  }
+
+  pLink->pNext = pLink->pPrev = 0;
+}
+
+/* 
+** Add page pPg to the list of free pages for the pager. If 
+** memory-management is enabled, also add the page to the global 
+** list of free pages.
+*/
+static void lruListAdd(PgHdr *pPg){
+  listAdd(&pPg->pPager->lru, &pPg->free, pPg);
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  if( !pPg->pPager->memDb ){
+    sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU));
+    listAdd(&sqlite3LruPageList, &pPg->gfree, pPg);
+    sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU));
+  }
+#endif
+}
+
+/* 
+** Remove page pPg from the list of free pages for the associated pager.
+** If memory-management is enabled, also remove pPg from the global list
+** of free pages.
+*/
+static void lruListRemove(PgHdr *pPg){
+  listRemove(&pPg->pPager->lru, &pPg->free, pPg);
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  if( !pPg->pPager->memDb ){
+    sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU));
+    listRemove(&sqlite3LruPageList, &pPg->gfree, pPg);
+    sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU));
+  }
+#endif
+}
+
+/* 
+** This function is called just after the needSync flag has been cleared
+** from all pages managed by pPager (usually because the journal file
+** has just been synced). It updates the pPager->lru.pFirstSynced variable
+** and, if memory-management is enabled, the sqlite3LruPageList.pFirstSynced
+** variable also.
+*/
+static void lruListSetFirstSynced(Pager *pPager){
+  pPager->lru.pFirstSynced = pPager->lru.pFirst;
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  if( !pPager->memDb ){
+    PgHdr *p;
+    sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU));
+    for(p=sqlite3LruPageList.pFirst; p && p->needSync; p=p->gfree.pNext);
+    assert(p==pPager->lru.pFirstSynced || p==sqlite3LruPageList.pFirstSynced);
+    sqlite3LruPageList.pFirstSynced = p;
+    sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU));
+  }
+#endif
+}
+
+/*
+** Return true if page *pPg has already been written to the statement
+** journal (or statement snapshot has been created, if *pPg is part
+** of an in-memory database).
+*/
+static int pageInStatement(PgHdr *pPg){
+  Pager *pPager = pPg->pPager;
+  if( MEMDB ){
+    return PGHDR_TO_HIST(pPg, pPager)->inStmt;
+  }else{
+    return sqlite3BitvecTest(pPager->pInStmt, pPg->pgno);
+  }
+}
+
+/*
+** Change the size of the pager hash table to N.  N must be a power
+** of two.
+*/
+static void pager_resize_hash_table(Pager *pPager, int N){
+  PgHdr **aHash, *pPg;
+  assert( N>0 && (N&(N-1))==0 );
+#ifdef SQLITE_MALLOC_SOFT_LIMIT
+  if( N*sizeof(aHash[0])>SQLITE_MALLOC_SOFT_LIMIT ){
+    N = SQLITE_MALLOC_SOFT_LIMIT/sizeof(aHash[0]);
+  }
+  if( N==pPager->nHash ) return;
+#endif
+  pagerLeave(pPager);
+  if( pPager->aHash!=0 ) sqlite3BeginBenignMalloc();
+  aHash = sqlite3MallocZero( sizeof(aHash[0])*N );
+  if( pPager->aHash!=0 ) sqlite3EndBenignMalloc();
+  pagerEnter(pPager);
+  if( aHash==0 ){
+    /* Failure to rehash is not an error.  It is only a performance hit. */
+    return;
+  }
+  sqlite3_free(pPager->aHash);
+  pPager->nHash = N;
+  pPager->aHash = aHash;
+  for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
+    int h;
+    if( pPg->pgno==0 ){
+      assert( pPg->pNextHash==0 && pPg->pPrevHash==0 );
+      continue;
+    }
+    h = pPg->pgno & (N-1);
+    pPg->pNextHash = aHash[h];
+    if( aHash[h] ){
+      aHash[h]->pPrevHash = pPg;
+    }
+    aHash[h] = pPg;
+    pPg->pPrevHash = 0;
+  }
+}
+
+/*
+** Read a 32-bit integer from the given file descriptor.  Store the integer
+** that is read in *pRes.  Return SQLITE_OK if everything worked, or an
+** error code is something goes wrong.
+**
+** All values are stored on disk as big-endian.
+*/
+static int read32bits(sqlite3_file *fd, i64 offset, u32 *pRes){
+  unsigned char ac[4];
+  int rc = sqlite3OsRead(fd, ac, sizeof(ac), offset);
+  if( rc==SQLITE_OK ){
+    *pRes = sqlite3Get4byte(ac);
+  }
+  return rc;
+}
+
+/*
+** Write a 32-bit integer into a string buffer in big-endian byte order.
+*/
+#define put32bits(A,B)  sqlite3Put4byte((u8*)A,B)
+
+/*
+** Write a 32-bit integer into the given file descriptor.  Return SQLITE_OK
+** on success or an error code is something goes wrong.
+*/
+static int write32bits(sqlite3_file *fd, i64 offset, u32 val){
+  char ac[4];
+  put32bits(ac, val);
+  return sqlite3OsWrite(fd, ac, 4, offset);
+}
+
+/*
+** If file pFd is open, call sqlite3OsUnlock() on it.
+*/
+static int osUnlock(sqlite3_file *pFd, int eLock){
+  if( !pFd->pMethods ){
+    return SQLITE_OK;
+  }
+  return sqlite3OsUnlock(pFd, eLock);
+}
+
+/*
+** This function determines whether or not the atomic-write optimization
+** can be used with this pager. The optimization can be used if:
+**
+**  (a) the value returned by OsDeviceCharacteristics() indicates that
+**      a database page may be written atomically, and
+**  (b) the value returned by OsSectorSize() is less than or equal
+**      to the page size.
+**
+** If the optimization cannot be used, 0 is returned. If it can be used,
+** then the value returned is the size of the journal file when it
+** contains rollback data for exactly one page.
+*/
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+static int jrnlBufferSize(Pager *pPager){
+  int dc;           /* Device characteristics */
+  int nSector;      /* Sector size */
+  int szPage;        /* Page size */
+  sqlite3_file *fd = pPager->fd;
+
+  if( fd->pMethods ){
+    dc = sqlite3OsDeviceCharacteristics(fd);
+    nSector = sqlite3OsSectorSize(fd);
+    szPage = pPager->pageSize;
+  }
+
+  assert(SQLITE_IOCAP_ATOMIC512==(512>>8));
+  assert(SQLITE_IOCAP_ATOMIC64K==(65536>>8));
+
+  if( !fd->pMethods || 
+       (dc & (SQLITE_IOCAP_ATOMIC|(szPage>>8)) && nSector<=szPage) ){
+    return JOURNAL_HDR_SZ(pPager) + JOURNAL_PG_SZ(pPager);
+  }
+  return 0;
+}
+#endif
+
+/*
+** This function should be called when an error occurs within the pager
+** code. The first argument is a pointer to the pager structure, the
+** second the error-code about to be returned by a pager API function. 
+** The value returned is a copy of the second argument to this function. 
+**
+** If the second argument is SQLITE_IOERR, SQLITE_CORRUPT, or SQLITE_FULL
+** the error becomes persistent. Until the persisten error is cleared,
+** subsequent API calls on this Pager will immediately return the same 
+** error code.
+**
+** A persistent error indicates that the contents of the pager-cache 
+** cannot be trusted. This state can be cleared by completely discarding 
+** the contents of the pager-cache. If a transaction was active when
+** the persistent error occured, then the rollback journal may need
+** to be replayed.
+*/
+static void pager_unlock(Pager *pPager);
+static int pager_error(Pager *pPager, int rc){
+  int rc2 = rc & 0xff;
+  assert(
+       pPager->errCode==SQLITE_FULL ||
+       pPager->errCode==SQLITE_OK ||
+       (pPager->errCode & 0xff)==SQLITE_IOERR
+  );
+  if(
+    rc2==SQLITE_FULL ||
+    rc2==SQLITE_IOERR ||
+    rc2==SQLITE_CORRUPT
+  ){
+    pPager->errCode = rc;
+    if( pPager->state==PAGER_UNLOCK && pPager->nRef==0 ){
+      /* If the pager is already unlocked, call pager_unlock() now to
+      ** clear the error state and ensure that the pager-cache is 
+      ** completely empty.
+      */
+      pager_unlock(pPager);
+    }
+  }
+  return rc;
+}
+
+/*
+** If SQLITE_CHECK_PAGES is defined then we do some sanity checking
+** on the cache using a hash function.  This is used for testing
+** and debugging only.
+*/
+#ifdef SQLITE_CHECK_PAGES
+/*
+** Return a 32-bit hash of the page data for pPage.
+*/
+static u32 pager_datahash(int nByte, unsigned char *pData){
+  u32 hash = 0;
+  int i;
+  for(i=0; i<nByte; i++){
+    hash = (hash*1039) + pData[i];
+  }
+  return hash;
+}
+static u32 pager_pagehash(PgHdr *pPage){
+  return pager_datahash(pPage->pPager->pageSize, 
+                        (unsigned char *)PGHDR_TO_DATA(pPage));
+}
+
+/*
+** The CHECK_PAGE macro takes a PgHdr* as an argument. If SQLITE_CHECK_PAGES
+** is defined, and NDEBUG is not defined, an assert() statement checks
+** that the page is either dirty or still matches the calculated page-hash.
+*/
+#define CHECK_PAGE(x) checkPage(x)
+static void checkPage(PgHdr *pPg){
+  Pager *pPager = pPg->pPager;
+  assert( !pPg->pageHash || pPager->errCode || MEMDB || pPg->dirty || 
+      pPg->pageHash==pager_pagehash(pPg) );
+}
+
+#else
+#define pager_datahash(X,Y)  0
+#define pager_pagehash(X)  0
+#define CHECK_PAGE(x)
+#endif
+
+/*
+** When this is called the journal file for pager pPager must be open.
+** The master journal file name is read from the end of the file and 
+** written into memory supplied by the caller. 
+**
+** zMaster must point to a buffer of at least nMaster bytes allocated by
+** the caller. This should be sqlite3_vfs.mxPathname+1 (to ensure there is
+** enough space to write the master journal name). If the master journal
+** name in the journal is longer than nMaster bytes (including a
+** nul-terminator), then this is handled as if no master journal name
+** were present in the journal.
+**
+** If no master journal file name is present zMaster[0] is set to 0 and
+** SQLITE_OK returned.
+*/
+static int readMasterJournal(sqlite3_file *pJrnl, char *zMaster, int nMaster){
+  int rc;
+  u32 len;
+  i64 szJ;
+  u32 cksum;
+  u32 u;                   /* Unsigned loop counter */
+  unsigned char aMagic[8]; /* A buffer to hold the magic header */
+
+  zMaster[0] = '\0';
+
+  rc = sqlite3OsFileSize(pJrnl, &szJ);
+  if( rc!=SQLITE_OK || szJ<16 ) return rc;
+
+  rc = read32bits(pJrnl, szJ-16, &len);
+  if( rc!=SQLITE_OK ) return rc;
+
+  if( len>=nMaster ){
+    return SQLITE_OK;
+  }
+
+  rc = read32bits(pJrnl, szJ-12, &cksum);
+  if( rc!=SQLITE_OK ) return rc;
+
+  rc = sqlite3OsRead(pJrnl, aMagic, 8, szJ-8);
+  if( rc!=SQLITE_OK || memcmp(aMagic, aJournalMagic, 8) ) return rc;
+
+  rc = sqlite3OsRead(pJrnl, zMaster, len, szJ-16-len);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+  zMaster[len] = '\0';
+
+  /* See if the checksum matches the master journal name */
+  for(u=0; u<len; u++){
+    cksum -= zMaster[u];
+   }
+  if( cksum ){
+    /* If the checksum doesn't add up, then one or more of the disk sectors
+    ** containing the master journal filename is corrupted. This means
+    ** definitely roll back, so just return SQLITE_OK and report a (nul)
+    ** master-journal filename.
+    */
+    zMaster[0] = '\0';
+  }
+   
+  return SQLITE_OK;
+}
+
+/*
+** Seek the journal file descriptor to the next sector boundary where a
+** journal header may be read or written. Pager.journalOff is updated with
+** the new seek offset.
+**
+** i.e for a sector size of 512:
+**
+** Input Offset              Output Offset
+** ---------------------------------------
+** 0                         0
+** 512                       512
+** 100                       512
+** 2000                      2048
+** 
+*/
+static void seekJournalHdr(Pager *pPager){
+  i64 offset = 0;
+  i64 c = pPager->journalOff;
+  if( c ){
+    offset = ((c-1)/JOURNAL_HDR_SZ(pPager) + 1) * JOURNAL_HDR_SZ(pPager);
+  }
+  assert( offset%JOURNAL_HDR_SZ(pPager)==0 );
+  assert( offset>=c );
+  assert( (offset-c)<JOURNAL_HDR_SZ(pPager) );
+  pPager->journalOff = offset;
+}
+
+/*
+** Write zeros over the header of the journal file.  This has the
+** effect of invalidating the journal file and committing the
+** transaction.
+*/
+static int zeroJournalHdr(Pager *pPager, int doTruncate){
+  int rc = SQLITE_OK;
+  static const char zeroHdr[28];
+
+  if( pPager->journalOff ){
+    i64 iLimit = pPager->journalSizeLimit;
+
+    IOTRACE(("JZEROHDR %p\n", pPager))
+    if( doTruncate || iLimit==0 ){
+      rc = sqlite3OsTruncate(pPager->jfd, 0);
+    }else{
+      rc = sqlite3OsWrite(pPager->jfd, zeroHdr, sizeof(zeroHdr), 0);
+    }
+    if( rc==SQLITE_OK && !pPager->noSync ){
+      rc = sqlite3OsSync(pPager->jfd, SQLITE_SYNC_DATAONLY|pPager->sync_flags);
+    }
+
+    /* At this point the transaction is committed but the write lock 
+    ** is still held on the file. If there is a size limit configured for 
+    ** the persistent journal and the journal file currently consumes more
+    ** space than that limit allows for, truncate it now. There is no need
+    ** to sync the file following this operation.
+    */
+    if( rc==SQLITE_OK && iLimit>0 ){
+      i64 sz;
+      rc = sqlite3OsFileSize(pPager->jfd, &sz);
+      if( rc==SQLITE_OK && sz>iLimit ){
+        rc = sqlite3OsTruncate(pPager->jfd, iLimit);
+      }
+    }
+  }
+  return rc;
+}
+
+/*
+** The journal file must be open when this routine is called. A journal
+** header (JOURNAL_HDR_SZ bytes) is written into the journal file at the
+** current location.
+**
+** The format for the journal header is as follows:
+** - 8 bytes: Magic identifying journal format.
+** - 4 bytes: Number of records in journal, or -1 no-sync mode is on.
+** - 4 bytes: Random number used for page hash.
+** - 4 bytes: Initial database page count.
+** - 4 bytes: Sector size used by the process that wrote this journal.
+** - 4 bytes: Database page size.
+** 
+** Followed by (JOURNAL_HDR_SZ - 28) bytes of unused space.
+*/
+static int writeJournalHdr(Pager *pPager){
+  int rc = SQLITE_OK;
+  char *zHeader = pPager->pTmpSpace;
+  int nHeader = pPager->pageSize;
+  int nWrite;
+
+  if( nHeader>JOURNAL_HDR_SZ(pPager) ){
+    nHeader = JOURNAL_HDR_SZ(pPager);
+  }
+
+  if( pPager->stmtHdrOff==0 ){
+    pPager->stmtHdrOff = pPager->journalOff;
+  }
+
+  seekJournalHdr(pPager);
+  pPager->journalHdr = pPager->journalOff;
+
+  memcpy(zHeader, aJournalMagic, sizeof(aJournalMagic));
+
+  /* 
+  ** Write the nRec Field - the number of page records that follow this
+  ** journal header. Normally, zero is written to this value at this time.
+  ** After the records are added to the journal (and the journal synced, 
+  ** if in full-sync mode), the zero is overwritten with the true number
+  ** of records (see syncJournal()).
+  **
+  ** A faster alternative is to write 0xFFFFFFFF to the nRec field. When
+  ** reading the journal this value tells SQLite to assume that the
+  ** rest of the journal file contains valid page records. This assumption
+  ** is dangerous, as if a failure occured whilst writing to the journal
+  ** file it may contain some garbage data. There are two scenarios
+  ** where this risk can be ignored:
+  **
+  **   * When the pager is in no-sync mode. Corruption can follow a
+  **     power failure in this case anyway.
+  **
+  **   * When the SQLITE_IOCAP_SAFE_APPEND flag is set. This guarantees
+  **     that garbage data is never appended to the journal file.
+  */
+  assert(pPager->fd->pMethods||pPager->noSync);
+  if( (pPager->noSync) 
+   || (sqlite3OsDeviceCharacteristics(pPager->fd)&SQLITE_IOCAP_SAFE_APPEND) 
+  ){
+    put32bits(&zHeader[sizeof(aJournalMagic)], 0xffffffff);
+  }else{
+    put32bits(&zHeader[sizeof(aJournalMagic)], 0);
+  }
+
+  /* The random check-hash initialiser */ 
+  sqlite3_randomness(sizeof(pPager->cksumInit), &pPager->cksumInit);
+  put32bits(&zHeader[sizeof(aJournalMagic)+4], pPager->cksumInit);
+  /* The initial database size */
+  put32bits(&zHeader[sizeof(aJournalMagic)+8], pPager->dbSize);
+  /* The assumed sector size for this process */
+  put32bits(&zHeader[sizeof(aJournalMagic)+12], pPager->sectorSize);
+  if( pPager->journalHdr==0 ){
+    /* The page size */
+    put32bits(&zHeader[sizeof(aJournalMagic)+16], pPager->pageSize);
+  }
+
+  for(nWrite=0; rc==SQLITE_OK&&nWrite<JOURNAL_HDR_SZ(pPager); nWrite+=nHeader){
+    IOTRACE(("JHDR %p %lld %d\n", pPager, pPager->journalHdr, nHeader))
+    rc = sqlite3OsWrite(pPager->jfd, zHeader, nHeader, pPager->journalOff);
+    pPager->journalOff += nHeader;
+  }
+
+  return rc;
+}
+
+/*
+** The journal file must be open when this is called. A journal header file
+** (JOURNAL_HDR_SZ bytes) is read from the current location in the journal
+** file. See comments above function writeJournalHdr() for a description of
+** the journal header format.
+**
+** If the header is read successfully, *nRec is set to the number of
+** page records following this header and *dbSize is set to the size of the
+** database before the transaction began, in pages. Also, pPager->cksumInit
+** is set to the value read from the journal header. SQLITE_OK is returned
+** in this case.
+**
+** If the journal header file appears to be corrupted, SQLITE_DONE is
+** returned and *nRec and *dbSize are not set.  If JOURNAL_HDR_SZ bytes
+** cannot be read from the journal file an error code is returned.
+*/
+static int readJournalHdr(
+  Pager *pPager, 
+  i64 journalSize,
+  u32 *pNRec, 
+  u32 *pDbSize
+){
+  int rc;
+  unsigned char aMagic[8]; /* A buffer to hold the magic header */
+  i64 jrnlOff;
+  int iPageSize;
+
+  seekJournalHdr(pPager);
+  if( pPager->journalOff+JOURNAL_HDR_SZ(pPager) > journalSize ){
+    return SQLITE_DONE;
+  }
+  jrnlOff = pPager->journalOff;
+
+  rc = sqlite3OsRead(pPager->jfd, aMagic, sizeof(aMagic), jrnlOff);
+  if( rc ) return rc;
+  jrnlOff += sizeof(aMagic);
+
+  if( memcmp(aMagic, aJournalMagic, sizeof(aMagic))!=0 ){
+    return SQLITE_DONE;
+  }
+
+  rc = read32bits(pPager->jfd, jrnlOff, pNRec);
+  if( rc ) return rc;
+
+  rc = read32bits(pPager->jfd, jrnlOff+4, &pPager->cksumInit);
+  if( rc ) return rc;
+
+  rc = read32bits(pPager->jfd, jrnlOff+8, pDbSize);
+  if( rc ) return rc;
+
+  rc = read32bits(pPager->jfd, jrnlOff+16, (u32 *)&iPageSize);
+  if( rc==SQLITE_OK 
+   && iPageSize>=512 
+   && iPageSize<=SQLITE_MAX_PAGE_SIZE 
+   && ((iPageSize-1)&iPageSize)==0 
+  ){
+    u16 pagesize = iPageSize;
+    rc = sqlite3PagerSetPagesize(pPager, &pagesize);
+  }
+  if( rc ) return rc;
+
+  /* Update the assumed sector-size to match the value used by 
+  ** the process that created this journal. If this journal was
+  ** created by a process other than this one, then this routine
+  ** is being called from within pager_playback(). The local value
+  ** of Pager.sectorSize is restored at the end of that routine.
+  */
+  rc = read32bits(pPager->jfd, jrnlOff+12, (u32 *)&pPager->sectorSize);
+  if( rc ) return rc;
+
+  pPager->journalOff += JOURNAL_HDR_SZ(pPager);
+  return SQLITE_OK;
+}
+
+
+/*
+** Write the supplied master journal name into the journal file for pager
+** pPager at the current location. The master journal name must be the last
+** thing written to a journal file. If the pager is in full-sync mode, the
+** journal file descriptor is advanced to the next sector boundary before
+** anything is written. The format is:
+**
+** + 4 bytes: PAGER_MJ_PGNO.
+** + N bytes: length of master journal name.
+** + 4 bytes: N
+** + 4 bytes: Master journal name checksum.
+** + 8 bytes: aJournalMagic[].
+**
+** The master journal page checksum is the sum of the bytes in the master
+** journal name.
+**
+** If zMaster is a NULL pointer (occurs for a single database transaction), 
+** this call is a no-op.
+*/
+static int writeMasterJournal(Pager *pPager, const char *zMaster){
+  int rc;
+  int len; 
+  int i; 
+  i64 jrnlOff;
+  i64 jrnlSize;
+  u32 cksum = 0;
+  char zBuf[sizeof(aJournalMagic)+2*4];
+
+  if( !zMaster || pPager->setMaster) return SQLITE_OK;
+  pPager->setMaster = 1;
+
+  len = strlen(zMaster);
+  for(i=0; i<len; i++){
+    cksum += zMaster[i];
+  }
+
+  /* If in full-sync mode, advance to the next disk sector before writing
+  ** the master journal name. This is in case the previous page written to
+  ** the journal has already been synced.
+  */
+  if( pPager->fullSync ){
+    seekJournalHdr(pPager);
+  }
+  jrnlOff = pPager->journalOff;
+  pPager->journalOff += (len+20);
+
+  rc = write32bits(pPager->jfd, jrnlOff, PAGER_MJ_PGNO(pPager));
+  if( rc!=SQLITE_OK ) return rc;
+  jrnlOff += 4;
+
+  rc = sqlite3OsWrite(pPager->jfd, zMaster, len, jrnlOff);
+  if( rc!=SQLITE_OK ) return rc;
+  jrnlOff += len;
+
+  put32bits(zBuf, len);
+  put32bits(&zBuf[4], cksum);
+  memcpy(&zBuf[8], aJournalMagic, sizeof(aJournalMagic));
+  rc = sqlite3OsWrite(pPager->jfd, zBuf, 8+sizeof(aJournalMagic), jrnlOff);
+  jrnlOff += 8+sizeof(aJournalMagic);
+  pPager->needSync = !pPager->noSync;
+
+  /* If the pager is in peristent-journal mode, then the physical 
+  ** journal-file may extend past the end of the master-journal name
+  ** and 8 bytes of magic data just written to the file. This is 
+  ** dangerous because the code to rollback a hot-journal file
+  ** will not be able to find the master-journal name to determine 
+  ** whether or not the journal is hot. 
+  **
+  ** Easiest thing to do in this scenario is to truncate the journal 
+  ** file to the required size.
+  */ 
+  if( (rc==SQLITE_OK)
+   && (rc = sqlite3OsFileSize(pPager->jfd, &jrnlSize))==SQLITE_OK
+   && jrnlSize>jrnlOff
+  ){
+    rc = sqlite3OsTruncate(pPager->jfd, jrnlOff);
+  }
+  return rc;
+}
+
+/*
+** Add or remove a page from the list of all pages that are in the
+** statement journal.
+**
+** The Pager keeps a separate list of pages that are currently in
+** the statement journal.  This helps the sqlite3PagerStmtCommit()
+** routine run MUCH faster for the common case where there are many
+** pages in memory but only a few are in the statement journal.
+*/
+static void page_add_to_stmt_list(PgHdr *pPg){
+  Pager *pPager = pPg->pPager;
+  PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
+  assert( MEMDB );
+  if( !pHist->inStmt ){
+    assert( pHist->pPrevStmt==0 && pHist->pNextStmt==0 );
+    if( pPager->pStmt ){
+      PGHDR_TO_HIST(pPager->pStmt, pPager)->pPrevStmt = pPg;
+    }
+    pHist->pNextStmt = pPager->pStmt;
+    pPager->pStmt = pPg;
+    pHist->inStmt = 1;
+  }
+}
+
+/*
+** Find a page in the hash table given its page number.  Return
+** a pointer to the page or NULL if not found.
+*/
+static PgHdr *pager_lookup(Pager *pPager, Pgno pgno){
+  PgHdr *p;
+  if( pPager->aHash==0 ) return 0;
+  p = pPager->aHash[pgno & (pPager->nHash-1)];
+  while( p && p->pgno!=pgno ){
+    p = p->pNextHash;
+  }
+  return p;
+}
+
+/*
+** Clear the in-memory cache.  This routine
+** sets the state of the pager back to what it was when it was first
+** opened.  Any outstanding pages are invalidated and subsequent attempts
+** to access those pages will likely result in a coredump.
+*/
+static void pager_reset(Pager *pPager){
+  PgHdr *pPg, *pNext;
+  if( pPager->errCode ) return;
+  for(pPg=pPager->pAll; pPg; pPg=pNext){
+    IOTRACE(("PGFREE %p %d\n", pPager, pPg->pgno));
+    PAGER_INCR(sqlite3_pager_pgfree_count);
+    pNext = pPg->pNextAll;
+    lruListRemove(pPg);
+    sqlite3PageFree(pPg->pData);
+    sqlite3_free(pPg);
+  }
+  assert(pPager->lru.pFirst==0);
+  assert(pPager->lru.pFirstSynced==0);
+  assert(pPager->lru.pLast==0);
+  pPager->pStmt = 0;
+  pPager->pAll = 0;
+  pPager->pDirty = 0;
+  pPager->nHash = 0;
+  sqlite3_free(pPager->aHash);
+  pPager->nPage = 0;
+  pPager->aHash = 0;
+  pPager->nRef = 0;
+}
+
+/*
+** Unlock the database file. 
+**
+** If the pager is currently in error state, discard the contents of 
+** the cache and reset the Pager structure internal state. If there is
+** an open journal-file, then the next time a shared-lock is obtained
+** on the pager file (by this or any other process), it will be
+** treated as a hot-journal and rolled back.
+*/
+static void pager_unlock(Pager *pPager){
+  if( !pPager->exclusiveMode ){
+    if( !MEMDB ){
+      int rc = osUnlock(pPager->fd, NO_LOCK);
+      if( rc ) pPager->errCode = rc;
+      pPager->dbSize = -1;
+      IOTRACE(("UNLOCK %p\n", pPager))
+
+      /* Always close the journal file when dropping the database lock.
+      ** Otherwise, another connection with journal_mode=delete might
+      ** delete the file out from under us.
+      */
+      if( pPager->journalOpen ){
+        sqlite3OsClose(pPager->jfd);
+        pPager->journalOpen = 0;
+        sqlite3BitvecDestroy(pPager->pInJournal);
+        pPager->pInJournal = 0;
+      }
+
+      /* If Pager.errCode is set, the contents of the pager cache cannot be
+      ** trusted. Now that the pager file is unlocked, the contents of the
+      ** cache can be discarded and the error code safely cleared.
+      */
+      if( pPager->errCode ){
+        if( rc==SQLITE_OK ) pPager->errCode = SQLITE_OK;
+        pager_reset(pPager);
+        if( pPager->stmtOpen ){
+          sqlite3OsClose(pPager->stfd);
+          sqlite3BitvecDestroy(pPager->pInStmt);
+          pPager->pInStmt = 0;
+        }
+        pPager->stmtOpen = 0;
+        pPager->stmtInUse = 0;
+        pPager->journalOff = 0;
+        pPager->journalStarted = 0;
+        pPager->stmtAutoopen = 0;
+        pPager->origDbSize = 0;
+      }
+    }
+
+    if( !MEMDB || pPager->errCode==SQLITE_OK ){
+      pPager->state = PAGER_UNLOCK;
+      pPager->changeCountDone = 0;
+    }
+  }
+}
+
+/*
+** Execute a rollback if a transaction is active and unlock the 
+** database file. If the pager has already entered the error state, 
+** do not attempt the rollback.
+*/
+static void pagerUnlockAndRollback(Pager *p){
+  /* assert( p->state>=PAGER_RESERVED || p->journalOpen==0 ); */
+  if( p->errCode==SQLITE_OK && p->state>=PAGER_RESERVED ){
+    sqlite3BeginBenignMalloc();
+    sqlite3PagerRollback(p);
+    sqlite3EndBenignMalloc();
+  }
+  pager_unlock(p);
+#if 0
+  assert( p->errCode || !p->journalOpen || (p->exclusiveMode&&!p->journalOff) );
+  assert( p->errCode || !p->stmtOpen || p->exclusiveMode );
+#endif
+}
+
+/*
+** This routine ends a transaction.  A transaction is ended by either
+** a COMMIT or a ROLLBACK.
+**
+** When this routine is called, the pager has the journal file open and
+** a RESERVED or EXCLUSIVE lock on the database.  This routine will release
+** the database lock and acquires a SHARED lock in its place if that is
+** the appropriate thing to do.  Release locks usually is appropriate,
+** unless we are in exclusive access mode or unless this is a 
+** COMMIT AND BEGIN or ROLLBACK AND BEGIN operation.
+**
+** The journal file is either deleted or truncated.
+**
+** TODO: Consider keeping the journal file open for temporary databases.
+** This might give a performance improvement on windows where opening
+** a file is an expensive operation.
+*/
+static int pager_end_transaction(Pager *pPager, int hasMaster){
+  PgHdr *pPg;
+  int rc = SQLITE_OK;
+  int rc2 = SQLITE_OK;
+  assert( !MEMDB );
+  if( pPager->state<PAGER_RESERVED ){
+    return SQLITE_OK;
+  }
+  sqlite3PagerStmtCommit(pPager);
+  if( pPager->stmtOpen && !pPager->exclusiveMode ){
+    sqlite3OsClose(pPager->stfd);
+    pPager->stmtOpen = 0;
+  }
+  if( pPager->journalOpen ){
+    if( pPager->exclusiveMode 
+     || pPager->journalMode==PAGER_JOURNALMODE_PERSIST
+    ){
+      rc = zeroJournalHdr(pPager, hasMaster);
+      pager_error(pPager, rc);
+      pPager->journalOff = 0;
+      pPager->journalStarted = 0;
+    }else{
+      sqlite3OsClose(pPager->jfd);
+      pPager->journalOpen = 0;
+      if( rc==SQLITE_OK && !pPager->tempFile ){
+        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
+      }
+    }
+    sqlite3BitvecDestroy(pPager->pInJournal);
+    pPager->pInJournal = 0;
+    for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
+      pPg->inJournal = 0;
+      pPg->dirty = 0;
+      pPg->needSync = 0;
+      pPg->alwaysRollback = 0;
+#ifdef SQLITE_CHECK_PAGES
+      pPg->pageHash = pager_pagehash(pPg);
+#endif
+    }
+    pPager->pDirty = 0;
+    pPager->dirtyCache = 0;
+    pPager->nRec = 0;
+  }else{
+    assert( pPager->pInJournal==0 );
+  }
+
+  if( !pPager->exclusiveMode ){
+    rc2 = osUnlock(pPager->fd, SHARED_LOCK);
+    pPager->state = PAGER_SHARED;
+  }else if( pPager->state==PAGER_SYNCED ){
+    pPager->state = PAGER_EXCLUSIVE;
+  }
+  pPager->origDbSize = 0;
+  pPager->setMaster = 0;
+  pPager->needSync = 0;
+  lruListSetFirstSynced(pPager);
+  pPager->dbSize = -1;
+  pPager->dbModified = 0;
+
+  return (rc==SQLITE_OK?rc2:rc);
+}
+
+/*
+** Compute and return a checksum for the page of data.
+**
+** This is not a real checksum.  It is really just the sum of the 
+** random initial value and the page number.  We experimented with
+** a checksum of the entire data, but that was found to be too slow.
+**
+** Note that the page number is stored at the beginning of data and
+** the checksum is stored at the end.  This is important.  If journal
+** corruption occurs due to a power failure, the most likely scenario
+** is that one end or the other of the record will be changed.  It is
+** much less likely that the two ends of the journal record will be
+** correct and the middle be corrupt.  Thus, this "checksum" scheme,
+** though fast and simple, catches the mostly likely kind of corruption.
+**
+** FIX ME:  Consider adding every 200th (or so) byte of the data to the
+** checksum.  That way if a single page spans 3 or more disk sectors and
+** only the middle sector is corrupt, we will still have a reasonable
+** chance of failing the checksum and thus detecting the problem.
+*/
+static u32 pager_cksum(Pager *pPager, const u8 *aData){
+  u32 cksum = pPager->cksumInit;
+  int i = pPager->pageSize-200;
+  while( i>0 ){
+    cksum += aData[i];
+    i -= 200;
+  }
+  return cksum;
+}
+
+/* Forward declaration */
+static void makeClean(PgHdr*);
+
+/*
+** Read a single page from the journal file opened on file descriptor
+** jfd.  Playback this one page.
+**
+** If useCksum==0 it means this journal does not use checksums.  Checksums
+** are not used in statement journals because statement journals do not
+** need to survive power failures.
+*/
+static int pager_playback_one_page(
+  Pager *pPager, 
+  sqlite3_file *jfd,
+  i64 offset,
+  int useCksum
+){
+  int rc;
+  PgHdr *pPg;                   /* An existing page in the cache */
+  Pgno pgno;                    /* The page number of a page in journal */
+  u32 cksum;                    /* Checksum used for sanity checking */
+  u8 *aData = (u8 *)pPager->pTmpSpace;   /* Temp storage for a page */
+
+  /* useCksum should be true for the main journal and false for
+  ** statement journals.  Verify that this is always the case
+  */
+  assert( jfd == (useCksum ? pPager->jfd : pPager->stfd) );
+  assert( aData );
+
+  rc = read32bits(jfd, offset, &pgno);
+  if( rc!=SQLITE_OK ) return rc;
+  rc = sqlite3OsRead(jfd, aData, pPager->pageSize, offset+4);
+  if( rc!=SQLITE_OK ) return rc;
+  pPager->journalOff += pPager->pageSize + 4;
+
+  /* Sanity checking on the page.  This is more important that I originally
+  ** thought.  If a power failure occurs while the journal is being written,
+  ** it could cause invalid data to be written into the journal.  We need to
+  ** detect this invalid data (with high probability) and ignore it.
+  */
+  if( pgno==0 || pgno==PAGER_MJ_PGNO(pPager) ){
+    return SQLITE_DONE;
+  }
+  if( pgno>(unsigned)pPager->dbSize ){
+    return SQLITE_OK;
+  }
+  if( useCksum ){
+    rc = read32bits(jfd, offset+pPager->pageSize+4, &cksum);
+    if( rc ) return rc;
+    pPager->journalOff += 4;
+    if( pager_cksum(pPager, aData)!=cksum ){
+      return SQLITE_DONE;
+    }
+  }
+
+  assert( pPager->state==PAGER_RESERVED || pPager->state>=PAGER_EXCLUSIVE );
+
+  /* If the pager is in RESERVED state, then there must be a copy of this
+  ** page in the pager cache. In this case just update the pager cache,
+  ** not the database file. The page is left marked dirty in this case.
+  **
+  ** An exception to the above rule: If the database is in no-sync mode
+  ** and a page is moved during an incremental vacuum then the page may
+  ** not be in the pager cache. Later: if a malloc() or IO error occurs
+  ** during a Movepage() call, then the page may not be in the cache
+  ** either. So the condition described in the above paragraph is not
+  ** assert()able.
+  **
+  ** If in EXCLUSIVE state, then we update the pager cache if it exists
+  ** and the main file. The page is then marked not dirty.
+  **
+  ** Ticket #1171:  The statement journal might contain page content that is
+  ** different from the page content at the start of the transaction.
+  ** This occurs when a page is changed prior to the start of a statement
+  ** then changed again within the statement.  When rolling back such a
+  ** statement we must not write to the original database unless we know
+  ** for certain that original page contents are synced into the main rollback
+  ** journal.  Otherwise, a power loss might leave modified data in the
+  ** database file without an entry in the rollback journal that can
+  ** restore the database to its original form.  Two conditions must be
+  ** met before writing to the database files. (1) the database must be
+  ** locked.  (2) we know that the original page content is fully synced
+  ** in the main journal either because the page is not in cache or else
+  ** the page is marked as needSync==0.
+  **
+  ** 2008-04-14:  When attempting to vacuum a corrupt database file, it
+  ** is possible to fail a statement on a database that does not yet exist.
+  ** Do not attempt to write if database file has never been opened.
+  */
+  pPg = pager_lookup(pPager, pgno);
+  PAGERTRACE4("PLAYBACK %d page %d hash(%08x)\n",
+               PAGERID(pPager), pgno, pager_datahash(pPager->pageSize, aData));
+  if( pPager->state>=PAGER_EXCLUSIVE && (pPg==0 || pPg->needSync==0)
+        && pPager->fd->pMethods ){
+    i64 offset = (pgno-1)*(i64)pPager->pageSize;
+    rc = sqlite3OsWrite(pPager->fd, aData, pPager->pageSize, offset);
+    if( pPg ){
+      makeClean(pPg);
+    }
+  }
+  if( pPg ){
+    /* No page should ever be explicitly rolled back that is in use, except
+    ** for page 1 which is held in use in order to keep the lock on the
+    ** database active. However such a page may be rolled back as a result
+    ** of an internal error resulting in an automatic call to
+    ** sqlite3PagerRollback().
+    */
+    void *pData;
+    /* assert( pPg->nRef==0 || pPg->pgno==1 ); */
+    pData = PGHDR_TO_DATA(pPg);
+    memcpy(pData, aData, pPager->pageSize);
+    if( pPager->xReiniter ){
+      pPager->xReiniter(pPg, pPager->pageSize);
+    }
+#ifdef SQLITE_CHECK_PAGES
+    pPg->pageHash = pager_pagehash(pPg);
+#endif
+    /* If this was page 1, then restore the value of Pager.dbFileVers.
+    ** Do this before any decoding. */
+    if( pgno==1 ){
+      memcpy(&pPager->dbFileVers, &((u8*)pData)[24],sizeof(pPager->dbFileVers));
+    }
+
+    /* Decode the page just read from disk */
+    CODEC1(pPager, pData, pPg->pgno, 3);
+  }
+  return rc;
+}
+
+/*
+** Parameter zMaster is the name of a master journal file. A single journal
+** file that referred to the master journal file has just been rolled back.
+** This routine checks if it is possible to delete the master journal file,
+** and does so if it is.
+**
+** Argument zMaster may point to Pager.pTmpSpace. So that buffer is not 
+** available for use within this function.
+**
+**
+** The master journal file contains the names of all child journals.
+** To tell if a master journal can be deleted, check to each of the
+** children.  If all children are either missing or do not refer to
+** a different master journal, then this master journal can be deleted.
+*/
+static int pager_delmaster(Pager *pPager, const char *zMaster){
+  sqlite3_vfs *pVfs = pPager->pVfs;
+  int rc;
+  int master_open = 0;
+  sqlite3_file *pMaster;
+  sqlite3_file *pJournal;
+  char *zMasterJournal = 0; /* Contents of master journal file */
+  i64 nMasterJournal;       /* Size of master journal file */
+
+  /* Open the master journal file exclusively in case some other process
+  ** is running this routine also. Not that it makes too much difference.
+  */
+  pMaster = (sqlite3_file *)sqlite3Malloc(pVfs->szOsFile * 2);
+  pJournal = (sqlite3_file *)(((u8 *)pMaster) + pVfs->szOsFile);
+  if( !pMaster ){
+    rc = SQLITE_NOMEM;
+  }else{
+    int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MASTER_JOURNAL);
+    rc = sqlite3OsOpen(pVfs, zMaster, pMaster, flags, 0);
+  }
+  if( rc!=SQLITE_OK ) goto delmaster_out;
+  master_open = 1;
+
+  rc = sqlite3OsFileSize(pMaster, &nMasterJournal);
+  if( rc!=SQLITE_OK ) goto delmaster_out;
+
+  if( nMasterJournal>0 ){
+    char *zJournal;
+    char *zMasterPtr = 0;
+    int nMasterPtr = pPager->pVfs->mxPathname+1;
+
+    /* Load the entire master journal file into space obtained from
+    ** sqlite3_malloc() and pointed to by zMasterJournal. 
+    */
+    zMasterJournal = (char *)sqlite3Malloc(nMasterJournal + nMasterPtr);
+    if( !zMasterJournal ){
+      rc = SQLITE_NOMEM;
+      goto delmaster_out;
+    }
+    zMasterPtr = &zMasterJournal[nMasterJournal];
+    rc = sqlite3OsRead(pMaster, zMasterJournal, nMasterJournal, 0);
+    if( rc!=SQLITE_OK ) goto delmaster_out;
+
+    zJournal = zMasterJournal;
+    while( (zJournal-zMasterJournal)<nMasterJournal ){
+      int exists;
+      rc = sqlite3OsAccess(pVfs, zJournal, SQLITE_ACCESS_EXISTS, &exists);
+      if( rc!=SQLITE_OK ){
+        goto delmaster_out;
+      }
+      if( exists ){
+        /* One of the journals pointed to by the master journal exists.
+        ** Open it and check if it points at the master journal. If
+        ** so, return without deleting the master journal file.
+        */
+        int c;
+        int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL);
+        rc = sqlite3OsOpen(pVfs, zJournal, pJournal, flags, 0);
+        if( rc!=SQLITE_OK ){
+          goto delmaster_out;
+        }
+
+        rc = readMasterJournal(pJournal, zMasterPtr, nMasterPtr);
+        sqlite3OsClose(pJournal);
+        if( rc!=SQLITE_OK ){
+          goto delmaster_out;
+        }
+
+        c = zMasterPtr[0]!=0 && strcmp(zMasterPtr, zMaster)==0;
+        if( c ){
+          /* We have a match. Do not delete the master journal file. */
+          goto delmaster_out;
+        }
+      }
+      zJournal += (strlen(zJournal)+1);
+    }
+  }
+  
+  rc = sqlite3OsDelete(pVfs, zMaster, 0);
+
+delmaster_out:
+  if( zMasterJournal ){
+    sqlite3_free(zMasterJournal);
+  }  
+  if( master_open ){
+    sqlite3OsClose(pMaster);
+  }
+  sqlite3_free(pMaster);
+  return rc;
+}
+
+
+static void pager_truncate_cache(Pager *pPager);
+
+/*
+** Truncate the main file of the given pager to the number of pages
+** indicated. Also truncate the cached representation of the file.
+**
+** Might might be the case that the file on disk is smaller than nPage.
+** This can happen, for example, if we are in the middle of a transaction
+** which has extended the file size and the new pages are still all held
+** in cache, then an INSERT or UPDATE does a statement rollback.  Some
+** operating system implementations can get confused if you try to
+** truncate a file to some size that is larger than it currently is,
+** so detect this case and write a single zero byte to the end of the new
+** file instead.
+*/
+static int pager_truncate(Pager *pPager, int nPage){
+  int rc = SQLITE_OK;
+  if( pPager->state>=PAGER_EXCLUSIVE && pPager->fd->pMethods ){
+    i64 currentSize, newSize;
+    rc = sqlite3OsFileSize(pPager->fd, &currentSize);
+    newSize = pPager->pageSize*(i64)nPage;
+    if( rc==SQLITE_OK && currentSize!=newSize ){
+      if( currentSize>newSize ){
+        rc = sqlite3OsTruncate(pPager->fd, newSize);
+      }else{
+        rc = sqlite3OsWrite(pPager->fd, "", 1, newSize-1);
+      }
+    }
+  }
+  if( rc==SQLITE_OK ){
+    pPager->dbSize = nPage;
+    pager_truncate_cache(pPager);
+  }
+  return rc;
+}
+
+/*
+** Set the sectorSize for the given pager.
+**
+** The sector size is at least as big as the sector size reported
+** by sqlite3OsSectorSize().  The minimum sector size is 512.
+*/
+static void setSectorSize(Pager *pPager){
+  assert(pPager->fd->pMethods||pPager->tempFile);
+  if( !pPager->tempFile ){
+    /* Sector size doesn't matter for temporary files. Also, the file
+    ** may not have been opened yet, in whcih case the OsSectorSize()
+    ** call will segfault.
+    */
+    pPager->sectorSize = sqlite3OsSectorSize(pPager->fd);
+  }
+  if( pPager->sectorSize<512 ){
+    pPager->sectorSize = 512;
+  }
+}
+
+/*
+** Playback the journal and thus restore the database file to
+** the state it was in before we started making changes.  
+**
+** The journal file format is as follows: 
+**
+**  (1)  8 byte prefix.  A copy of aJournalMagic[].
+**  (2)  4 byte big-endian integer which is the number of valid page records
+**       in the journal.  If this value is 0xffffffff, then compute the
+**       number of page records from the journal size.
+**  (3)  4 byte big-endian integer which is the initial value for the 
+**       sanity checksum.
+**  (4)  4 byte integer which is the number of pages to truncate the
+**       database to during a rollback.
+**  (5)  4 byte big-endian integer which is the sector size.  The header
+**       is this many bytes in size.
+**  (6)  4 byte big-endian integer which is the page case.
+**  (7)  4 byte integer which is the number of bytes in the master journal
+**       name.  The value may be zero (indicate that there is no master
+**       journal.)
+**  (8)  N bytes of the master journal name.  The name will be nul-terminated
+**       and might be shorter than the value read from (5).  If the first byte
+**       of the name is \000 then there is no master journal.  The master
+**       journal name is stored in UTF-8.
+**  (9)  Zero or more pages instances, each as follows:
+**        +  4 byte page number.
+**        +  pPager->pageSize bytes of data.
+**        +  4 byte checksum
+**
+** When we speak of the journal header, we mean the first 8 items above.
+** Each entry in the journal is an instance of the 9th item.
+**
+** Call the value from the second bullet "nRec".  nRec is the number of
+** valid page entries in the journal.  In most cases, you can compute the
+** value of nRec from the size of the journal file.  But if a power
+** failure occurred while the journal was being written, it could be the
+** case that the size of the journal file had already been increased but
+** the extra entries had not yet made it safely to disk.  In such a case,
+** the value of nRec computed from the file size would be too large.  For
+** that reason, we always use the nRec value in the header.
+**
+** If the nRec value is 0xffffffff it means that nRec should be computed
+** from the file size.  This value is used when the user selects the
+** no-sync option for the journal.  A power failure could lead to corruption
+** in this case.  But for things like temporary table (which will be
+** deleted when the power is restored) we don't care.  
+**
+** If the file opened as the journal file is not a well-formed
+** journal file then all pages up to the first corrupted page are rolled
+** back (or no pages if the journal header is corrupted). The journal file
+** is then deleted and SQLITE_OK returned, just as if no corruption had
+** been encountered.
+**
+** If an I/O or malloc() error occurs, the journal-file is not deleted
+** and an error code is returned.
+*/
+static int pager_playback(Pager *pPager, int isHot){
+  sqlite3_vfs *pVfs = pPager->pVfs;
+  i64 szJ;                 /* Size of the journal file in bytes */
+  u32 nRec;                /* Number of Records in the journal */
+  u32 u;                   /* Unsigned loop counter */
+  Pgno mxPg = 0;           /* Size of the original file in pages */
+  int rc;                  /* Result code of a subroutine */
+  int res = 1;             /* Value returned by sqlite3OsAccess() */
+  char *zMaster = 0;       /* Name of master journal file if any */
+
+  /* Figure out how many records are in the journal.  Abort early if
+  ** the journal is empty.
+  */
+  assert( pPager->journalOpen );
+  rc = sqlite3OsFileSize(pPager->jfd, &szJ);
+  if( rc!=SQLITE_OK || szJ==0 ){
+    goto end_playback;
+  }
+
+  /* Read the master journal name from the journal, if it is present.
+  ** If a master journal file name is specified, but the file is not
+  ** present on disk, then the journal is not hot and does not need to be
+  ** played back.
+  */
+  zMaster = pPager->pTmpSpace;
+  rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);
+  if( rc==SQLITE_OK && zMaster[0] ){
+    rc = sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS, &res);
+  }
+  zMaster = 0;
+  if( rc!=SQLITE_OK || !res ){
+    goto end_playback;
+  }
+  pPager->journalOff = 0;
+
+  /* This loop terminates either when the readJournalHdr() call returns
+  ** SQLITE_DONE or an IO error occurs. */
+  while( 1 ){
+
+    /* Read the next journal header from the journal file.  If there are
+    ** not enough bytes left in the journal file for a complete header, or
+    ** it is corrupted, then a process must of failed while writing it.
+    ** This indicates nothing more needs to be rolled back.
+    */
+    rc = readJournalHdr(pPager, szJ, &nRec, &mxPg);
+    if( rc!=SQLITE_OK ){ 
+      if( rc==SQLITE_DONE ){
+        rc = SQLITE_OK;
+      }
+      goto end_playback;
+    }
+
+    /* If nRec is 0xffffffff, then this journal was created by a process
+    ** working in no-sync mode. This means that the rest of the journal
+    ** file consists of pages, there are no more journal headers. Compute
+    ** the value of nRec based on this assumption.
+    */
+    if( nRec==0xffffffff ){
+      assert( pPager->journalOff==JOURNAL_HDR_SZ(pPager) );
+      nRec = (szJ - JOURNAL_HDR_SZ(pPager))/JOURNAL_PG_SZ(pPager);
+    }
+
+    /* If nRec is 0 and this rollback is of a transaction created by this
+    ** process and if this is the final header in the journal, then it means
+    ** that this part of the journal was being filled but has not yet been
+    ** synced to disk.  Compute the number of pages based on the remaining
+    ** size of the file.
+    **
+    ** The third term of the test was added to fix ticket #2565.
+    */
+    if( nRec==0 && !isHot &&
+        pPager->journalHdr+JOURNAL_HDR_SZ(pPager)==pPager->journalOff ){
+      nRec = (szJ - pPager->journalOff) / JOURNAL_PG_SZ(pPager);
+    }
+
+    /* If this is the first header read from the journal, truncate the
+    ** database file back to its original size.
+    */
+    if( pPager->journalOff==JOURNAL_HDR_SZ(pPager) ){
+      rc = pager_truncate(pPager, mxPg);
+      if( rc!=SQLITE_OK ){
+        goto end_playback;
+      }
+    }
+
+    /* Copy original pages out of the journal and back into the database file.
+    */
+    for(u=0; u<nRec; u++){
+      rc = pager_playback_one_page(pPager, pPager->jfd, pPager->journalOff, 1);
+      if( rc!=SQLITE_OK ){
+        if( rc==SQLITE_DONE ){
+          rc = SQLITE_OK;
+          pPager->journalOff = szJ;
+          break;
+        }else{
+          goto end_playback;
+        }
+      }
+    }
+  }
+  /*NOTREACHED*/
+  assert( 0 );
+
+end_playback:
+  if( rc==SQLITE_OK ){
+    zMaster = pPager->pTmpSpace;
+    rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);
+  }
+  if( rc==SQLITE_OK ){
+    rc = pager_end_transaction(pPager, zMaster[0]!='\0');
+  }
+  if( rc==SQLITE_OK && zMaster[0] ){
+    /* If there was a master journal and this routine will return success,
+    ** see if it is possible to delete the master journal.
+    */
+    rc = pager_delmaster(pPager, zMaster);
+  }
+
+  /* The Pager.sectorSize variable may have been updated while rolling
+  ** back a journal created by a process with a different sector size
+  ** value. Reset it to the correct value for this process.
+  */
+  setSectorSize(pPager);
+  return rc;
+}
+
+/*
+** Playback the statement journal.
+**
+** This is similar to playing back the transaction journal but with
+** a few extra twists.
+**
+**    (1)  The number of pages in the database file at the start of
+**         the statement is stored in pPager->stmtSize, not in the
+**         journal file itself.
+**
+**    (2)  In addition to playing back the statement journal, also
+**         playback all pages of the transaction journal beginning
+**         at offset pPager->stmtJSize.
+*/
+static int pager_stmt_playback(Pager *pPager){
+  i64 szJ;                 /* Size of the full journal */
+  i64 hdrOff;
+  int nRec;                /* Number of Records */
+  int i;                   /* Loop counter */
+  int rc;
+
+  szJ = pPager->journalOff;
+
+  /* Set hdrOff to be the offset just after the end of the last journal
+  ** page written before the first journal-header for this statement
+  ** transaction was written, or the end of the file if no journal
+  ** header was written.
+  */
+  hdrOff = pPager->stmtHdrOff;
+  assert( pPager->fullSync || !hdrOff );
+  if( !hdrOff ){
+    hdrOff = szJ;
+  }
+  
+  /* Truncate the database back to its original size.
+  */
+  rc = pager_truncate(pPager, pPager->stmtSize);
+  assert( pPager->state>=PAGER_SHARED );
+
+  /* Figure out how many records are in the statement journal.
+  */
+  assert( pPager->stmtInUse && pPager->journalOpen );
+  nRec = pPager->stmtNRec;
+  
+  /* Copy original pages out of the statement journal and back into the
+  ** database file.  Note that the statement journal omits checksums from
+  ** each record since power-failure recovery is not important to statement
+  ** journals.
+  */
+  for(i=0; i<nRec; i++){
+    i64 offset = i*(4+pPager->pageSize);
+    rc = pager_playback_one_page(pPager, pPager->stfd, offset, 0);
+    assert( rc!=SQLITE_DONE );
+    if( rc!=SQLITE_OK ) goto end_stmt_playback;
+  }
+
+  /* Now roll some pages back from the transaction journal. Pager.stmtJSize
+  ** was the size of the journal file when this statement was started, so
+  ** everything after that needs to be rolled back, either into the
+  ** database, the memory cache, or both.
+  **
+  ** If it is not zero, then Pager.stmtHdrOff is the offset to the start
+  ** of the first journal header written during this statement transaction.
+  */
+  pPager->journalOff = pPager->stmtJSize;
+  pPager->cksumInit = pPager->stmtCksum;
+  while( pPager->journalOff < hdrOff ){
+    rc = pager_playback_one_page(pPager, pPager->jfd, pPager->journalOff, 1);
+    assert( rc!=SQLITE_DONE );
+    if( rc!=SQLITE_OK ) goto end_stmt_playback;
+  }
+
+  while( pPager->journalOff < szJ ){
+    u32 nJRec;         /* Number of Journal Records */
+    u32 dummy;
+    rc = readJournalHdr(pPager, szJ, &nJRec, &dummy);
+    if( rc!=SQLITE_OK ){
+      assert( rc!=SQLITE_DONE );
+      goto end_stmt_playback;
+    }
+    if( nJRec==0 ){
+      nJRec = (szJ - pPager->journalOff) / (pPager->pageSize+8);
+    }
+    for(i=nJRec-1; i>=0 && pPager->journalOff < szJ; i--){
+      rc = pager_playback_one_page(pPager, pPager->jfd, pPager->journalOff, 1);
+      assert( rc!=SQLITE_DONE );
+      if( rc!=SQLITE_OK ) goto end_stmt_playback;
+    }
+  }
+
+  pPager->journalOff = szJ;
+  
+end_stmt_playback:
+  if( rc==SQLITE_OK) {
+    pPager->journalOff = szJ;
+    /* pager_reload_cache(pPager); */
+  }
+  return rc;
+}
+
+/*
+** Change the maximum number of in-memory pages that are allowed.
+*/
+void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
+  if( mxPage>10 ){
+    pPager->mxPage = mxPage;
+  }else{
+    pPager->mxPage = 10;
+  }
+}
+
+/*
+** Adjust the robustness of the database to damage due to OS crashes
+** or power failures by changing the number of syncs()s when writing
+** the rollback journal.  There are three levels:
+**
+**    OFF       sqlite3OsSync() is never called.  This is the default
+**              for temporary and transient files.
+**
+**    NORMAL    The journal is synced once before writes begin on the
+**              database.  This is normally adequate protection, but
+**              it is theoretically possible, though very unlikely,
+**              that an inopertune power failure could leave the journal
+**              in a state which would cause damage to the database
+**              when it is rolled back.
+**
+**    FULL      The journal is synced twice before writes begin on the
+**              database (with some additional information - the nRec field
+**              of the journal header - being written in between the two
+**              syncs).  If we assume that writing a
+**              single disk sector is atomic, then this mode provides
+**              assurance that the journal will not be corrupted to the
+**              point of causing damage to the database during rollback.
+**
+** Numeric values associated with these states are OFF==1, NORMAL=2,
+** and FULL=3.
+*/
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+void sqlite3PagerSetSafetyLevel(Pager *pPager, int level, int full_fsync){
+  pPager->noSync =  level==1 || pPager->tempFile;
+  pPager->fullSync = level==3 && !pPager->tempFile;
+  pPager->sync_flags = (full_fsync?SQLITE_SYNC_FULL:SQLITE_SYNC_NORMAL);
+  if( pPager->noSync ) pPager->needSync = 0;
+}
+#endif
+
+/*
+** The following global variable is incremented whenever the library
+** attempts to open a temporary file.  This information is used for
+** testing and analysis only.  
+*/
+#ifdef SQLITE_TEST
+int sqlite3_opentemp_count = 0;
+#endif
+
+/*
+** Open a temporary file. 
+**
+** Write the file descriptor into *fd.  Return SQLITE_OK on success or some
+** other error code if we fail. The OS will automatically delete the temporary
+** file when it is closed.
+*/
+static int sqlite3PagerOpentemp(
+  Pager *pPager,        /* The pager object */
+  sqlite3_file *pFile,  /* Write the file descriptor here */
+  int vfsFlags          /* Flags passed through to the VFS */
+){
+  int rc;
+
+#ifdef SQLITE_TEST
+  sqlite3_opentemp_count++;  /* Used for testing and analysis only */
+#endif
+
+  vfsFlags |=  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |
+            SQLITE_OPEN_EXCLUSIVE | SQLITE_OPEN_DELETEONCLOSE;
+  rc = sqlite3OsOpen(pPager->pVfs, 0, pFile, vfsFlags, 0);
+  assert( rc!=SQLITE_OK || pFile->pMethods );
+  return rc;
+}
+
+/*
+** Create a new page cache and put a pointer to the page cache in *ppPager.
+** The file to be cached need not exist.  The file is not locked until
+** the first call to sqlite3PagerGet() and is only held open until the
+** last page is released using sqlite3PagerUnref().
+**
+** If zFilename is NULL then a randomly-named temporary file is created
+** and used as the file to be cached.  The file will be deleted
+** automatically when it is closed.
+**
+** If zFilename is ":memory:" then all information is held in cache.
+** It is never written to disk.  This can be used to implement an
+** in-memory database.
+*/
+int sqlite3PagerOpen(
+  sqlite3_vfs *pVfs,       /* The virtual file system to use */
+  Pager **ppPager,         /* Return the Pager structure here */
+  const char *zFilename,   /* Name of the database file to open */
+  int nExtra,              /* Extra bytes append to each in-memory page */
+  int flags,               /* flags controlling this file */
+  int vfsFlags             /* flags passed through to sqlite3_vfs.xOpen() */
+){
+  u8 *pPtr;
+  Pager *pPager = 0;
+  int rc = SQLITE_OK;
+  int i;
+  int tempFile = 0;
+  int memDb = 0;
+  int readOnly = 0;
+  int useJournal = (flags & PAGER_OMIT_JOURNAL)==0;
+  int noReadlock = (flags & PAGER_NO_READLOCK)!=0;
+  int journalFileSize = sqlite3JournalSize(pVfs);
+  int szPageDflt = SQLITE_DEFAULT_PAGE_SIZE;
+  char *zPathname = 0;
+  int nPathname = 0;
+
+  /* The default return is a NULL pointer */
+  *ppPager = 0;
+
+  /* Compute and store the full pathname in an allocated buffer pointed
+  ** to by zPathname, length nPathname. Or, if this is a temporary file,
+  ** leave both nPathname and zPathname set to 0.
+  */
+  if( zFilename && zFilename[0] ){
+    nPathname = pVfs->mxPathname+1;
+    zPathname = sqlite3Malloc(nPathname*2);
+    if( zPathname==0 ){
+      return SQLITE_NOMEM;
+    }
+#ifndef SQLITE_OMIT_MEMORYDB
+    if( strcmp(zFilename,":memory:")==0 ){
+      memDb = 1;
+      zPathname[0] = 0;
+    }else
+#endif
+    {
+      rc = sqlite3OsFullPathname(pVfs, zFilename, nPathname, zPathname);
+    }
+    if( rc!=SQLITE_OK ){
+      sqlite3_free(zPathname);
+      return rc;
+    }
+    nPathname = strlen(zPathname);
+  }
+
+  /* Allocate memory for the pager structure */
+  pPager = sqlite3MallocZero(
+    sizeof(*pPager) +           /* Pager structure */
+    journalFileSize +           /* The journal file structure */ 
+    pVfs->szOsFile * 3 +        /* The main db and two journal files */ 
+    3*nPathname + 40            /* zFilename, zDirectory, zJournal */
+  );
+  if( !pPager ){
+    sqlite3_free(zPathname);
+    return SQLITE_NOMEM;
+  }
+  pPtr = (u8 *)&pPager[1];
+  pPager->vfsFlags = vfsFlags;
+  pPager->fd = (sqlite3_file*)&pPtr[pVfs->szOsFile*0];
+  pPager->stfd = (sqlite3_file*)&pPtr[pVfs->szOsFile*1];
+  pPager->jfd = (sqlite3_file*)&pPtr[pVfs->szOsFile*2];
+  pPager->zFilename = (char*)&pPtr[pVfs->szOsFile*2+journalFileSize];
+  pPager->zDirectory = &pPager->zFilename[nPathname+1];
+  pPager->zJournal = &pPager->zDirectory[nPathname+1];
+  pPager->pVfs = pVfs;
+  if( zPathname ){
+    memcpy(pPager->zFilename, zPathname, nPathname+1);
+    sqlite3_free(zPathname);
+  }
+
+  /* Open the pager file.
+  */
+  if( zFilename && zFilename[0] && !memDb ){
+    if( nPathname>(pVfs->mxPathname - sizeof("-journal")) ){
+      rc = SQLITE_CANTOPEN;
+    }else{
+      int fout = 0;
+      rc = sqlite3OsOpen(pVfs, pPager->zFilename, pPager->fd,
+                         pPager->vfsFlags, &fout);
+      readOnly = (fout&SQLITE_OPEN_READONLY);
+
+      /* If the file was successfully opened for read/write access,
+      ** choose a default page size in case we have to create the
+      ** database file. The default page size is the maximum of:
+      **
+      **    + SQLITE_DEFAULT_PAGE_SIZE,
+      **    + The value returned by sqlite3OsSectorSize()
+      **    + The largest page size that can be written atomically.
+      */
+      if( rc==SQLITE_OK && !readOnly ){
+        int iSectorSize = sqlite3OsSectorSize(pPager->fd);
+        if( szPageDflt<iSectorSize ){
+          szPageDflt = iSectorSize;
+        }
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+        {
+          int iDc = sqlite3OsDeviceCharacteristics(pPager->fd);
+          int ii;
+          assert(SQLITE_IOCAP_ATOMIC512==(512>>8));
+          assert(SQLITE_IOCAP_ATOMIC64K==(65536>>8));
+          assert(SQLITE_MAX_DEFAULT_PAGE_SIZE<=65536);
+          for(ii=szPageDflt; ii<=SQLITE_MAX_DEFAULT_PAGE_SIZE; ii=ii*2){
+            if( iDc&(SQLITE_IOCAP_ATOMIC|(ii>>8)) ) szPageDflt = ii;
+          }
+        }
+#endif
+        if( szPageDflt>SQLITE_MAX_DEFAULT_PAGE_SIZE ){
+          szPageDflt = SQLITE_MAX_DEFAULT_PAGE_SIZE;
+        }
+      }
+    }
+  }else if( !memDb ){
+    /* If a temporary file is requested, it is not opened immediately.
+    ** In this case we accept the default page size and delay actually
+    ** opening the file until the first call to OsWrite().
+    */ 
+    tempFile = 1;
+    pPager->state = PAGER_EXCLUSIVE;
+  }
+
+  if( pPager && rc==SQLITE_OK ){
+    pPager->pTmpSpace = sqlite3PageMalloc(szPageDflt);
+  }
+
+  /* If an error occured in either of the blocks above.
+  ** Free the Pager structure and close the file.
+  ** Since the pager is not allocated there is no need to set 
+  ** any Pager.errMask variables.
+  */
+  if( !pPager || !pPager->pTmpSpace ){
+    sqlite3OsClose(pPager->fd);
+    sqlite3_free(pPager);
+    return ((rc==SQLITE_OK)?SQLITE_NOMEM:rc);
+  }
+
+  PAGERTRACE3("OPEN %d %s\n", FILEHANDLEID(pPager->fd), pPager->zFilename);
+  IOTRACE(("OPEN %p %s\n", pPager, pPager->zFilename))
+
+  /* Fill in Pager.zDirectory[] */
+  memcpy(pPager->zDirectory, pPager->zFilename, nPathname+1);
+  for(i=strlen(pPager->zDirectory); i>0 && pPager->zDirectory[i-1]!='/'; i--){}
+  if( i>0 ) pPager->zDirectory[i-1] = 0;
+
+  /* Fill in Pager.zJournal[] */
+  if( zPathname ){
+    memcpy(pPager->zJournal, pPager->zFilename, nPathname);
+    memcpy(&pPager->zJournal[nPathname], "-journal", 9);
+  }else{
+    pPager->zJournal = 0;
+  }
+
+  /* pPager->journalOpen = 0; */
+  pPager->useJournal = useJournal && !memDb;
+  pPager->noReadlock = noReadlock && readOnly;
+  /* pPager->stmtOpen = 0; */
+  /* pPager->stmtInUse = 0; */
+  /* pPager->nRef = 0; */
+  pPager->dbSize = memDb-1;
+  pPager->pageSize = szPageDflt;
+  /* pPager->stmtSize = 0; */
+  /* pPager->stmtJSize = 0; */
+  /* pPager->nPage = 0; */
+  pPager->mxPage = 100;
+  pPager->mxPgno = SQLITE_MAX_PAGE_COUNT;
+  /* pPager->state = PAGER_UNLOCK; */
+  assert( pPager->state == (tempFile ? PAGER_EXCLUSIVE : PAGER_UNLOCK) );
+  /* pPager->errMask = 0; */
+  pPager->tempFile = tempFile;
+  assert( tempFile==PAGER_LOCKINGMODE_NORMAL 
+          || tempFile==PAGER_LOCKINGMODE_EXCLUSIVE );
+  assert( PAGER_LOCKINGMODE_EXCLUSIVE==1 );
+  pPager->exclusiveMode = tempFile; 
+  pPager->memDb = memDb;
+  pPager->readOnly = readOnly;
+  /* pPager->needSync = 0; */
+  pPager->noSync = pPager->tempFile || !useJournal;
+  pPager->fullSync = (pPager->noSync?0:1);
+  pPager->sync_flags = SQLITE_SYNC_NORMAL;
+  /* pPager->pFirst = 0; */
+  /* pPager->pFirstSynced = 0; */
+  /* pPager->pLast = 0; */
+  pPager->nExtra = FORCE_ALIGNMENT(nExtra);
+  pPager->journalSizeLimit = SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT;
+  assert(pPager->fd->pMethods||memDb||tempFile);
+  if( !memDb ){
+    setSectorSize(pPager);
+  }
+  /* pPager->pBusyHandler = 0; */
+  /* memset(pPager->aHash, 0, sizeof(pPager->aHash)); */
+  *ppPager = pPager;
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  pPager->iInUseMM = 0;
+  pPager->iInUseDB = 0;
+  if( !memDb ){
+#ifndef SQLITE_MUTEX_NOOP
+    sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM2);
+#endif
+    sqlite3_mutex_enter(mutex);
+    pPager->pNext = sqlite3PagerList;
+    if( sqlite3PagerList ){
+      assert( sqlite3PagerList->pPrev==0 );
+      sqlite3PagerList->pPrev = pPager;
+    }
+    pPager->pPrev = 0;
+    sqlite3PagerList = pPager;
+    sqlite3_mutex_leave(mutex);
+  }
+#endif
+  return SQLITE_OK;
+}
+
+/*
+** Set the busy handler function.
+*/
+void sqlite3PagerSetBusyhandler(Pager *pPager, BusyHandler *pBusyHandler){
+  pPager->pBusyHandler = pBusyHandler;
+}
+
+/*
+** Set the destructor for this pager.  If not NULL, the destructor is called
+** when the reference count on each page reaches zero.  The destructor can
+** be used to clean up information in the extra segment appended to each page.
+**
+** The destructor is not called as a result sqlite3PagerClose().  
+** Destructors are only called by sqlite3PagerUnref().
+*/
+void sqlite3PagerSetDestructor(Pager *pPager, void (*xDesc)(DbPage*,int)){
+  pPager->xDestructor = xDesc;
+}
+
+/*
+** Set the reinitializer for this pager.  If not NULL, the reinitializer
+** is called when the content of a page in cache is restored to its original
+** value as a result of a rollback.  The callback gives higher-level code
+** an opportunity to restore the EXTRA section to agree with the restored
+** page data.
+*/
+void sqlite3PagerSetReiniter(Pager *pPager, void (*xReinit)(DbPage*,int)){
+  pPager->xReiniter = xReinit;
+}
+
+/*
+** Set the page size to *pPageSize. If the suggest new page size is
+** inappropriate, then an alternative page size is set to that
+** value before returning.
+*/
+int sqlite3PagerSetPagesize(Pager *pPager, u16 *pPageSize){
+  int rc = SQLITE_OK;
+  u16 pageSize = *pPageSize;
+  assert( pageSize==0 || (pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE) );
+  if( pageSize && pageSize!=pPager->pageSize 
+   && !pPager->memDb && pPager->nRef==0 
+  ){
+    char *pNew = (char *)sqlite3PageMalloc(pageSize);
+    if( !pNew ){
+      rc = SQLITE_NOMEM;
+    }else{
+      pagerEnter(pPager);
+      pager_reset(pPager);
+      pPager->pageSize = pageSize;
+      setSectorSize(pPager);
+      sqlite3PageFree(pPager->pTmpSpace);
+      pPager->pTmpSpace = pNew;
+      pagerLeave(pPager);
+    }
+  }
+  *pPageSize = pPager->pageSize;
+  return rc;
+}
+
+/*
+** Return a pointer to the "temporary page" buffer held internally
+** by the pager.  This is a buffer that is big enough to hold the
+** entire content of a database page.  This buffer is used internally
+** during rollback and will be overwritten whenever a rollback
+** occurs.  But other modules are free to use it too, as long as
+** no rollbacks are happening.
+*/
+void *sqlite3PagerTempSpace(Pager *pPager){
+  return pPager->pTmpSpace;
+}
+
+/*
+** Attempt to set the maximum database page count if mxPage is positive. 
+** Make no changes if mxPage is zero or negative.  And never reduce the
+** maximum page count below the current size of the database.
+**
+** Regardless of mxPage, return the current maximum page count.
+*/
+int sqlite3PagerMaxPageCount(Pager *pPager, int mxPage){
+  if( mxPage>0 ){
+    pPager->mxPgno = mxPage;
+  }
+  sqlite3PagerPagecount(pPager, 0);
+  return pPager->mxPgno;
+}
+
+/*
+** The following set of routines are used to disable the simulated
+** I/O error mechanism.  These routines are used to avoid simulated
+** errors in places where we do not care about errors.
+**
+** Unless -DSQLITE_TEST=1 is used, these routines are all no-ops
+** and generate no code.
+*/
+#ifdef SQLITE_TEST
+extern int sqlite3_io_error_pending;
+extern int sqlite3_io_error_hit;
+static int saved_cnt;
+void disable_simulated_io_errors(void){
+  saved_cnt = sqlite3_io_error_pending;
+  sqlite3_io_error_pending = -1;
+}
+void enable_simulated_io_errors(void){
+  sqlite3_io_error_pending = saved_cnt;
+}
+#else
+# define disable_simulated_io_errors()
+# define enable_simulated_io_errors()
+#endif
+
+/*
+** Read the first N bytes from the beginning of the file into memory
+** that pDest points to. 
+**
+** No error checking is done. The rational for this is that this function 
+** may be called even if the file does not exist or contain a header. In 
+** these cases sqlite3OsRead() will return an error, to which the correct 
+** response is to zero the memory at pDest and continue.  A real IO error 
+** will presumably recur and be picked up later (Todo: Think about this).
+*/
+int sqlite3PagerReadFileheader(Pager *pPager, int N, unsigned char *pDest){
+  int rc = SQLITE_OK;
+  memset(pDest, 0, N);
+  assert(MEMDB||pPager->fd->pMethods||pPager->tempFile);
+  if( pPager->fd->pMethods ){
+    IOTRACE(("DBHDR %p 0 %d\n", pPager, N))
+    rc = sqlite3OsRead(pPager->fd, pDest, N, 0);
+    if( rc==SQLITE_IOERR_SHORT_READ ){
+      rc = SQLITE_OK;
+    }
+  }
+  return rc;
+}
+
+/*
+** Return the total number of pages in the disk file associated with
+** pPager. 
+**
+** If the PENDING_BYTE lies on the page directly after the end of the
+** file, then consider this page part of the file too. For example, if
+** PENDING_BYTE is byte 4096 (the first byte of page 5) and the size of the
+** file is 4096 bytes, 5 is returned instead of 4.
+*/
+int sqlite3PagerPagecount(Pager *pPager, int *pnPage){
+  i64 n = 0;
+  int rc;
+  assert( pPager!=0 );
+  if( pPager->errCode ){
+    return pPager->errCode;
+  }
+  if( pPager->dbSize>=0 ){
+    n = pPager->dbSize;
+  } else {
+    assert(pPager->fd->pMethods||pPager->tempFile);
+    if( (pPager->fd->pMethods)
+     && (rc = sqlite3OsFileSize(pPager->fd, &n))!=SQLITE_OK ){
+      pPager->nRef++;
+      pager_error(pPager, rc);
+      pPager->nRef--;
+      return rc;
+    }
+    if( n>0 && n<pPager->pageSize ){
+      n = 1;
+    }else{
+      n /= pPager->pageSize;
+    }
+    if( pPager->state!=PAGER_UNLOCK ){
+      pPager->dbSize = n;
+    }
+  }
+  if( n==(PENDING_BYTE/pPager->pageSize) ){
+    n++;
+  }
+  if( n>pPager->mxPgno ){
+    pPager->mxPgno = n;
+  }
+  if( pnPage ){
+    *pnPage = n;
+  }
+  return SQLITE_OK;
+}
+
+
+#ifndef SQLITE_OMIT_MEMORYDB
+/*
+** Clear a PgHistory block
+*/
+static void clearHistory(PgHistory *pHist){
+  sqlite3PageFree(pHist->pOrig);
+  sqlite3PageFree(pHist->pStmt);
+  pHist->pOrig = 0;
+  pHist->pStmt = 0;
+}
+#else
+#define clearHistory(x)
+#endif
+
+/*
+** Forward declaration
+*/
+static int syncJournal(Pager*);
+
+/*
+** Unlink pPg from its hash chain. Also set the page number to 0 to indicate
+** that the page is not part of any hash chain. This is required because the
+** sqlite3PagerMovepage() routine can leave a page in the 
+** pNextFree/pPrevFree list that is not a part of any hash-chain.
+*/
+static void unlinkHashChain(Pager *pPager, PgHdr *pPg){
+  if( pPg->pgno==0 ){
+    assert( pPg->pNextHash==0 && pPg->pPrevHash==0 );
+    return;
+  }
+  if( pPg->pNextHash ){
+    pPg->pNextHash->pPrevHash = pPg->pPrevHash;
+  }
+  if( pPg->pPrevHash ){
+    assert( pPager->aHash[pPg->pgno & (pPager->nHash-1)]!=pPg );
+    pPg->pPrevHash->pNextHash = pPg->pNextHash;
+  }else{
+    int h = pPg->pgno & (pPager->nHash-1);
+    pPager->aHash[h] = pPg->pNextHash;
+  }
+  if( MEMDB ){
+    clearHistory(PGHDR_TO_HIST(pPg, pPager));
+  }
+  pPg->pgno = 0;
+  pPg->pNextHash = pPg->pPrevHash = 0;
+}
+
+/*
+** Unlink a page from the free list (the list of all pages where nRef==0)
+** and from its hash collision chain.
+*/
+static void unlinkPage(PgHdr *pPg){
+  Pager *pPager = pPg->pPager;
+
+  /* Unlink from free page list */
+  lruListRemove(pPg);
+
+  /* Unlink from the pgno hash table */
+  unlinkHashChain(pPager, pPg);
+}
+
+/*
+** This routine is used to truncate the cache when a database
+** is truncated.  Drop from the cache all pages whose pgno is
+** larger than pPager->dbSize and is unreferenced.
+**
+** Referenced pages larger than pPager->dbSize are zeroed.
+**
+** Actually, at the point this routine is called, it would be
+** an error to have a referenced page.  But rather than delete
+** that page and guarantee a subsequent segfault, it seems better
+** to zero it and hope that we error out sanely.
+*/
+static void pager_truncate_cache(Pager *pPager){
+  PgHdr *pPg;
+  PgHdr **ppPg;
+  int dbSize = pPager->dbSize;
+
+  ppPg = &pPager->pAll;
+  while( (pPg = *ppPg)!=0 ){
+    if( pPg->pgno<=dbSize ){
+      ppPg = &pPg->pNextAll;
+    }else if( pPg->nRef>0 ){
+      memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
+      ppPg = &pPg->pNextAll;
+    }else{
+      *ppPg = pPg->pNextAll;
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+      if( *ppPg ){
+        (*ppPg)->pPrevAll = pPg->pPrevAll;
+      }
+#endif
+      IOTRACE(("PGFREE %p %d\n", pPager, pPg->pgno));
+      PAGER_INCR(sqlite3_pager_pgfree_count);
+      unlinkPage(pPg);
+      makeClean(pPg);
+      sqlite3PageFree(pPg->pData);
+      sqlite3_free(pPg);
+      pPager->nPage--;
+    }
+  }
+}
+
+/*
+** Try to obtain a lock on a file.  Invoke the busy callback if the lock
+** is currently not available.  Repeat until the busy callback returns
+** false or until the lock succeeds.
+**
+** Return SQLITE_OK on success and an error code if we cannot obtain
+** the lock.
+*/
+static int pager_wait_on_lock(Pager *pPager, int locktype){
+  int rc;
+
+  /* The OS lock values must be the same as the Pager lock values */
+  assert( PAGER_SHARED==SHARED_LOCK );
+  assert( PAGER_RESERVED==RESERVED_LOCK );
+  assert( PAGER_EXCLUSIVE==EXCLUSIVE_LOCK );
+
+  /* If the file is currently unlocked then the size must be unknown */
+  assert( pPager->state>=PAGER_SHARED || pPager->dbSize<0 || MEMDB );
+
+  if( pPager->state>=locktype ){
+    rc = SQLITE_OK;
+  }else{
+    if( pPager->pBusyHandler ) pPager->pBusyHandler->nBusy = 0;
+    do {
+      rc = sqlite3OsLock(pPager->fd, locktype);
+    }while( rc==SQLITE_BUSY && sqlite3InvokeBusyHandler(pPager->pBusyHandler) );
+    if( rc==SQLITE_OK ){
+      pPager->state = locktype;
+      IOTRACE(("LOCK %p %d\n", pPager, locktype))
+    }
+  }
+  return rc;
+}
+
+/*
+** Truncate the file to the number of pages specified.
+*/
+int sqlite3PagerTruncate(Pager *pPager, Pgno nPage){
+  int rc;
+  assert( pPager->state>=PAGER_SHARED || MEMDB );
+  sqlite3PagerPagecount(pPager, 0);
+  if( pPager->errCode ){
+    rc = pPager->errCode;
+    return rc;
+  }
+  if( nPage>=(unsigned)pPager->dbSize ){
+    return SQLITE_OK;
+  }
+  if( MEMDB ){
+    pPager->dbSize = nPage;
+    pager_truncate_cache(pPager);
+    return SQLITE_OK;
+  }
+  pagerEnter(pPager);
+  rc = syncJournal(pPager);
+  pagerLeave(pPager);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  /* Get an exclusive lock on the database before truncating. */
+  pagerEnter(pPager);
+  rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
+  pagerLeave(pPager);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  rc = pager_truncate(pPager, nPage);
+  return rc;
+}
+
+/*
+** Shutdown the page cache.  Free all memory and close all files.
+**
+** If a transaction was in progress when this routine is called, that
+** transaction is rolled back.  All outstanding pages are invalidated
+** and their memory is freed.  Any attempt to use a page associated
+** with this page cache after this function returns will likely
+** result in a coredump.
+**
+** This function always succeeds. If a transaction is active an attempt
+** is made to roll it back. If an error occurs during the rollback 
+** a hot journal may be left in the filesystem but no error is returned
+** to the caller.
+*/
+int sqlite3PagerClose(Pager *pPager){
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  if( !MEMDB ){
+#ifndef SQLITE_MUTEX_NOOP
+    sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM2);
+#endif
+    sqlite3_mutex_enter(mutex);
+    if( pPager->pPrev ){
+      pPager->pPrev->pNext = pPager->pNext;
+    }else{
+      sqlite3PagerList = pPager->pNext;
+    }
+    if( pPager->pNext ){
+      pPager->pNext->pPrev = pPager->pPrev;
+    }
+    sqlite3_mutex_leave(mutex);
+  }
+#endif
+
+  disable_simulated_io_errors();
+  sqlite3BeginBenignMalloc();
+  pPager->errCode = 0;
+  pPager->exclusiveMode = 0;
+  pager_reset(pPager);
+  pagerUnlockAndRollback(pPager);
+  enable_simulated_io_errors();
+  sqlite3EndBenignMalloc();
+  PAGERTRACE2("CLOSE %d\n", PAGERID(pPager));
+  IOTRACE(("CLOSE %p\n", pPager))
+  if( pPager->journalOpen ){
+    sqlite3OsClose(pPager->jfd);
+  }
+  sqlite3BitvecDestroy(pPager->pInJournal);
+  if( pPager->stmtOpen ){
+    sqlite3OsClose(pPager->stfd);
+  }
+  sqlite3OsClose(pPager->fd);
+  /* Temp files are automatically deleted by the OS
+  ** if( pPager->tempFile ){
+  **   sqlite3OsDelete(pPager->zFilename);
+  ** }
+  */
+
+  sqlite3_free(pPager->aHash);
+  sqlite3PageFree(pPager->pTmpSpace);
+  sqlite3_free(pPager);
+  return SQLITE_OK;
+}
+
+#if !defined(NDEBUG) || defined(SQLITE_TEST)
+/*
+** Return the page number for the given page data.
+*/
+Pgno sqlite3PagerPagenumber(DbPage *p){
+  return p->pgno;
+}
+#endif
+
+/*
+** The page_ref() function increments the reference count for a page.
+** If the page is currently on the freelist (the reference count is zero) then
+** remove it from the freelist.
+**
+** For non-test systems, page_ref() is a macro that calls _page_ref()
+** online of the reference count is zero.  For test systems, page_ref()
+** is a real function so that we can set breakpoints and trace it.
+*/
+static void _page_ref(PgHdr *pPg){
+  if( pPg->nRef==0 ){
+    /* The page is currently on the freelist.  Remove it. */
+    lruListRemove(pPg);
+    pPg->pPager->nRef++;
+  }
+  pPg->nRef++;
+}
+#ifdef SQLITE_DEBUG
+  static void page_ref(PgHdr *pPg){
+    if( pPg->nRef==0 ){
+      _page_ref(pPg);
+    }else{
+      pPg->nRef++;
+    }
+  }
+#else
+# define page_ref(P)   ((P)->nRef==0?_page_ref(P):(void)(P)->nRef++)
+#endif
+
+/*
+** Increment the reference count for a page.  The input pointer is
+** a reference to the page data.
+*/
+int sqlite3PagerRef(DbPage *pPg){
+  pagerEnter(pPg->pPager);
+  page_ref(pPg);
+  pagerLeave(pPg->pPager);
+  return SQLITE_OK;
+}
+
+/*
+** Sync the journal.  In other words, make sure all the pages that have
+** been written to the journal have actually reached the surface of the
+** disk.  It is not safe to modify the original database file until after
+** the journal has been synced.  If the original database is modified before
+** the journal is synced and a power failure occurs, the unsynced journal
+** data would be lost and we would be unable to completely rollback the
+** database changes.  Database corruption would occur.
+** 
+** This routine also updates the nRec field in the header of the journal.
+** (See comments on the pager_playback() routine for additional information.)
+** If the sync mode is FULL, two syncs will occur.  First the whole journal
+** is synced, then the nRec field is updated, then a second sync occurs.
+**
+** For temporary databases, we do not care if we are able to rollback
+** after a power failure, so no sync occurs.
+**
+** If the IOCAP_SEQUENTIAL flag is set for the persistent media on which
+** the database is stored, then OsSync() is never called on the journal
+** file. In this case all that is required is to update the nRec field in
+** the journal header.
+**
+** This routine clears the needSync field of every page current held in
+** memory.
+*/
+static int syncJournal(Pager *pPager){
+  PgHdr *pPg;
+  int rc = SQLITE_OK;
+
+  /* Sync the journal before modifying the main database
+  ** (assuming there is a journal and it needs to be synced.)
+  */
+  if( pPager->needSync ){
+    if( !pPager->tempFile ){
+      int iDc = sqlite3OsDeviceCharacteristics(pPager->fd);
+      assert( pPager->journalOpen );
+
+      if( 0==(iDc&SQLITE_IOCAP_SAFE_APPEND) ){
+        /* Write the nRec value into the journal file header. If in
+        ** full-synchronous mode, sync the journal first. This ensures that
+        ** all data has really hit the disk before nRec is updated to mark
+        ** it as a candidate for rollback.
+        **
+        ** This is not required if the persistent media supports the
+        ** SAFE_APPEND property. Because in this case it is not possible 
+        ** for garbage data to be appended to the file, the nRec field
+        ** is populated with 0xFFFFFFFF when the journal header is written
+        ** and never needs to be updated.
+        */
+        i64 jrnlOff;
+        if( pPager->fullSync && 0==(iDc&SQLITE_IOCAP_SEQUENTIAL) ){
+          PAGERTRACE2("SYNC journal of %d\n", PAGERID(pPager));
+          IOTRACE(("JSYNC %p\n", pPager))
+          rc = sqlite3OsSync(pPager->jfd, pPager->sync_flags);
+          if( rc!=0 ) return rc;
+        }
+
+        jrnlOff = pPager->journalHdr + sizeof(aJournalMagic);
+        IOTRACE(("JHDR %p %lld %d\n", pPager, jrnlOff, 4));
+        rc = write32bits(pPager->jfd, jrnlOff, pPager->nRec);
+        if( rc ) return rc;
+      }
+      if( 0==(iDc&SQLITE_IOCAP_SEQUENTIAL) ){
+        PAGERTRACE2("SYNC journal of %d\n", PAGERID(pPager));
+        IOTRACE(("JSYNC %p\n", pPager))
+        rc = sqlite3OsSync(pPager->jfd, pPager->sync_flags| 
+          (pPager->sync_flags==SQLITE_SYNC_FULL?SQLITE_SYNC_DATAONLY:0)
+        );
+        if( rc!=0 ) return rc;
+      }
+      pPager->journalStarted = 1;
+    }
+    pPager->needSync = 0;
+
+    /* Erase the needSync flag from every page.
+    */
+    for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
+      pPg->needSync = 0;
+    }
+    lruListSetFirstSynced(pPager);
+  }
+
+#ifndef NDEBUG
+  /* If the Pager.needSync flag is clear then the PgHdr.needSync
+  ** flag must also be clear for all pages.  Verify that this
+  ** invariant is true.
+  */
+  else{
+    for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
+      assert( pPg->needSync==0 );
+    }
+    assert( pPager->lru.pFirstSynced==pPager->lru.pFirst );
+  }
+#endif
+
+  return rc;
+}
+
+/*
+** Merge two lists of pages connected by pDirty and in pgno order.
+** Do not both fixing the pPrevDirty pointers.
+*/
+static PgHdr *merge_pagelist(PgHdr *pA, PgHdr *pB){
+  PgHdr result, *pTail;
+  pTail = &result;
+  while( pA && pB ){
+    if( pA->pgno<pB->pgno ){
+      pTail->pDirty = pA;
+      pTail = pA;
+      pA = pA->pDirty;
+    }else{
+      pTail->pDirty = pB;
+      pTail = pB;
+      pB = pB->pDirty;
+    }
+  }
+  if( pA ){
+    pTail->pDirty = pA;
+  }else if( pB ){
+    pTail->pDirty = pB;
+  }else{
+    pTail->pDirty = 0;
+  }
+  return result.pDirty;
+}
+
+/*
+** Sort the list of pages in accending order by pgno.  Pages are
+** connected by pDirty pointers.  The pPrevDirty pointers are
+** corrupted by this sort.
+*/
+#define N_SORT_BUCKET_ALLOC 25
+#define N_SORT_BUCKET       25
+#ifdef SQLITE_TEST
+  int sqlite3_pager_n_sort_bucket = 0;
+  #undef N_SORT_BUCKET
+  #define N_SORT_BUCKET \
+   (sqlite3_pager_n_sort_bucket?sqlite3_pager_n_sort_bucket:N_SORT_BUCKET_ALLOC)
+#endif
+static PgHdr *sort_pagelist(PgHdr *pIn){
+  PgHdr *a[N_SORT_BUCKET_ALLOC], *p;
+  int i;
+  memset(a, 0, sizeof(a));
+  while( pIn ){
+    p = pIn;
+    pIn = p->pDirty;
+    p->pDirty = 0;
+    for(i=0; i<N_SORT_BUCKET-1; i++){
+      if( a[i]==0 ){
+        a[i] = p;
+        break;
+      }else{
+        p = merge_pagelist(a[i], p);
+        a[i] = 0;
+      }
+    }
+    if( i==N_SORT_BUCKET-1 ){
+      /* Coverage: To get here, there need to be 2^(N_SORT_BUCKET) 
+      ** elements in the input list. This is possible, but impractical.
+      ** Testing this line is the point of global variable
+      ** sqlite3_pager_n_sort_bucket.
+      */
+      a[i] = merge_pagelist(a[i], p);
+    }
+  }
+  p = a[0];
+  for(i=1; i<N_SORT_BUCKET; i++){
+    p = merge_pagelist(p, a[i]);
+  }
+  return p;
+}
+
+/*
+** Given a list of pages (connected by the PgHdr.pDirty pointer) write
+** every one of those pages out to the database file and mark them all
+** as clean.
+*/
+static int pager_write_pagelist(PgHdr *pList){
+  Pager *pPager;
+  PgHdr *p;
+  int rc;
+
+  if( pList==0 ) return SQLITE_OK;
+  pPager = pList->pPager;
+
+  /* At this point there may be either a RESERVED or EXCLUSIVE lock on the
+  ** database file. If there is already an EXCLUSIVE lock, the following
+  ** calls to sqlite3OsLock() are no-ops.
+  **
+  ** Moving the lock from RESERVED to EXCLUSIVE actually involves going
+  ** through an intermediate state PENDING.   A PENDING lock prevents new
+  ** readers from attaching to the database but is unsufficient for us to
+  ** write.  The idea of a PENDING lock is to prevent new readers from
+  ** coming in while we wait for existing readers to clear.
+  **
+  ** While the pager is in the RESERVED state, the original database file
+  ** is unchanged and we can rollback without having to playback the
+  ** journal into the original database file.  Once we transition to
+  ** EXCLUSIVE, it means the database file has been changed and any rollback
+  ** will require a journal playback.
+  */
+  rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  pList = sort_pagelist(pList);
+  for(p=pList; p; p=p->pDirty){
+    assert( p->dirty );
+    p->dirty = 0;
+  }
+  while( pList ){
+
+    /* If the file has not yet been opened, open it now. */
+    if( !pPager->fd->pMethods ){
+      assert(pPager->tempFile);
+      rc = sqlite3PagerOpentemp(pPager, pPager->fd, pPager->vfsFlags);
+      if( rc ) return rc;
+    }
+
+    /* If there are dirty pages in the page cache with page numbers greater
+    ** than Pager.dbSize, this means sqlite3PagerTruncate() was called to
+    ** make the file smaller (presumably by auto-vacuum code). Do not write
+    ** any such pages to the file.
+    */
+    if( pList->pgno<=pPager->dbSize ){
+      i64 offset = (pList->pgno-1)*(i64)pPager->pageSize;
+      char *pData = CODEC2(pPager, PGHDR_TO_DATA(pList), pList->pgno, 6);
+      PAGERTRACE4("STORE %d page %d hash(%08x)\n",
+                   PAGERID(pPager), pList->pgno, pager_pagehash(pList));
+      IOTRACE(("PGOUT %p %d\n", pPager, pList->pgno));
+      rc = sqlite3OsWrite(pPager->fd, pData, pPager->pageSize, offset);
+      PAGER_INCR(sqlite3_pager_writedb_count);
+      PAGER_INCR(pPager->nWrite);
+      if( pList->pgno==1 ){
+        memcpy(&pPager->dbFileVers, &pData[24], sizeof(pPager->dbFileVers));
+      }
+    }
+#ifndef NDEBUG
+    else{
+      PAGERTRACE3("NOSTORE %d page %d\n", PAGERID(pPager), pList->pgno);
+    }
+#endif
+    if( rc ) return rc;
+#ifdef SQLITE_CHECK_PAGES
+    pList->pageHash = pager_pagehash(pList);
+#endif
+    pList = pList->pDirty;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Collect every dirty page into a dirty list and
+** return a pointer to the head of that list.  All pages are
+** collected even if they are still in use.
+*/
+static PgHdr *pager_get_all_dirty_pages(Pager *pPager){
+
+#ifndef NDEBUG
+  /* Verify the sanity of the dirty list when we are running
+  ** in debugging mode.  This is expensive, so do not
+  ** do this on a normal build. */
+  int n1 = 0;
+  int n2 = 0;
+  PgHdr *p;
+  for(p=pPager->pAll; p; p=p->pNextAll){ if( p->dirty ) n1++; }
+  for(p=pPager->pDirty; p; p=p->pDirty){ n2++; }
+  assert( n1==n2 );
+#endif
+
+  return pPager->pDirty;
+}
+
+/*
+** Return 1 if there is a hot journal on the given pager.
+** A hot journal is one that needs to be played back.
+**
+** If the current size of the database file is 0 but a journal file
+** exists, that is probably an old journal left over from a prior
+** database with the same name.  Just delete the journal.
+**
+** Return negative if unable to determine the status of the journal.
+**
+** This routine does not open the journal file to examine its
+** content.  Hence, the journal might contain the name of a master
+** journal file that has been deleted, and hence not be hot.  Or
+** the header of the journal might be zeroed out.  This routine
+** does not discover these cases of a non-hot journal - if the
+** journal file exists and is not empty this routine assumes it
+** is hot.  The pager_playback() routine will discover that the
+** journal file is not really hot and will no-op.
+*/
+static int hasHotJournal(Pager *pPager, int *pExists){
+  sqlite3_vfs *pVfs = pPager->pVfs;
+  int rc = SQLITE_OK;
+  *pExists = 0;
+  if( pPager->useJournal && pPager->fd->pMethods ){
+    int exists;
+    int locked;
+
+    rc = sqlite3OsAccess(pVfs, pPager->zJournal, SQLITE_ACCESS_EXISTS, &exists);
+    if( rc==SQLITE_OK && exists ){
+      rc = sqlite3OsCheckReservedLock(pPager->fd, &locked);
+    }
+
+    if( rc==SQLITE_OK && exists && !locked ){
+      int nPage;
+      rc = sqlite3PagerPagecount(pPager, &nPage);
+      if( rc==SQLITE_OK ){
+        if( nPage==0 ){
+          sqlite3OsDelete(pVfs, pPager->zJournal, 0);
+        }else{
+          *pExists = 1;
+        }
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Try to find a page in the cache that can be recycled. 
+**
+** This routine may return SQLITE_IOERR, SQLITE_FULL or SQLITE_OK. It 
+** does not set the pPager->errCode variable.
+*/
+static int pager_recycle(Pager *pPager, PgHdr **ppPg){
+  PgHdr *pPg;
+  *ppPg = 0;
+
+  /* It is illegal to call this function unless the pager object
+  ** pointed to by pPager has at least one free page (page with nRef==0).
+  */ 
+  assert(!MEMDB);
+  assert(pPager->lru.pFirst);
+
+  /* Find a page to recycle.  Try to locate a page that does not
+  ** require us to do an fsync() on the journal.
+  */
+  pPg = pPager->lru.pFirstSynced;
+
+  /* If we could not find a page that does not require an fsync()
+  ** on the journal file then fsync the journal file.  This is a
+  ** very slow operation, so we work hard to avoid it.  But sometimes
+  ** it can't be helped.
+  */
+  if( pPg==0 && pPager->lru.pFirst ){
+    if( !pPager->errCode ){
+      int iDc = sqlite3OsDeviceCharacteristics(pPager->fd);
+      int rc = syncJournal(pPager);
+      if( rc!=0 ){
+        return rc;
+      }
+      if( pPager->fullSync && 0==(iDc&SQLITE_IOCAP_SAFE_APPEND) ){
+        /* If in full-sync mode, write a new journal header into the
+        ** journal file. This is done to avoid ever modifying a journal
+        ** header that is involved in the rollback of pages that have
+        ** already been written to the database (in case the header is
+        ** trashed when the nRec field is updated).
+        */
+        pPager->nRec = 0;
+        assert( pPager->journalOff > 0 );
+        assert( pPager->doNotSync==0 );
+        rc = writeJournalHdr(pPager);
+        if( rc!=0 ){
+          return rc;
+        }
+      }
+    }
+    pPg = pPager->lru.pFirst;
+  }
+
+  assert( pPg->nRef==0 );
+
+  /* Write the page to the database file if it is dirty.
+  */
+  if( pPg->dirty && !pPager->errCode ){
+    int rc;
+    assert( pPg->needSync==0 );
+    makeClean(pPg);
+    pPg->dirty = 1;
+    pPg->pDirty = 0;
+    rc = pager_write_pagelist( pPg );
+    pPg->dirty = 0;
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+  }
+  assert( pPg->dirty==0 || pPager->errCode );
+
+  /* If the page we are recycling is marked as alwaysRollback, then
+  ** set the global alwaysRollback flag, thus disabling the
+  ** sqlite3PagerDontRollback() optimization for the rest of this transaction.
+  ** It is necessary to do this because the page marked alwaysRollback
+  ** might be reloaded at a later time but at that point we won't remember
+  ** that is was marked alwaysRollback.  This means that all pages must
+  ** be marked as alwaysRollback from here on out.
+  */
+  if( pPg->alwaysRollback ){
+    IOTRACE(("ALWAYS_ROLLBACK %p\n", pPager))
+    pPager->alwaysRollback = 1;
+  }
+
+  /* Unlink the old page from the free list and the hash table
+  */
+  unlinkPage(pPg);
+  assert( pPg->pgno==0 );
+
+  *ppPg = pPg;
+  return SQLITE_OK;
+}
+
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+/*
+** This function is called to free superfluous dynamically allocated memory
+** held by the pager system. Memory in use by any SQLite pager allocated
+** by the current thread may be sqlite3_free()ed.
+**
+** nReq is the number of bytes of memory required. Once this much has
+** been released, the function returns. The return value is the total number 
+** of bytes of memory released.
+*/
+int sqlite3PagerReleaseMemory(int nReq){
+  int nReleased = 0;          /* Bytes of memory released so far */
+  Pager *pPager;              /* For looping over pagers */
+  BusyHandler *savedBusy;     /* Saved copy of the busy handler */
+  int rc = SQLITE_OK;
+
+  /* Acquire the memory-management mutex
+  */
+#ifndef SQLITE_MUTEX_NOOP
+  sqlite3_mutex *mutex;       /* The MEM2 mutex */
+  mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM2);
+#endif
+  sqlite3_mutex_enter(mutex);
+
+  /* Signal all database connections that memory management wants
+  ** to have access to the pagers.
+  */
+  for(pPager=sqlite3PagerList; pPager; pPager=pPager->pNext){
+     pPager->iInUseMM = 1;
+  }
+
+  while( rc==SQLITE_OK && (nReq<0 || nReleased<nReq) ){
+    PgHdr *pPg;
+    PgHdr *pRecycled;
+ 
+    /* Try to find a page to recycle that does not require a sync(). If
+    ** this is not possible, find one that does require a sync().
+    */
+    sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU));
+    pPg = sqlite3LruPageList.pFirstSynced;
+    while( pPg && (pPg->needSync || pPg->pPager->iInUseDB) ){
+      pPg = pPg->gfree.pNext;
+    }
+    if( !pPg ){
+      pPg = sqlite3LruPageList.pFirst;
+      while( pPg && pPg->pPager->iInUseDB ){
+        pPg = pPg->gfree.pNext;
+      }
+    }
+    sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU));
+
+    /* If pPg==0, then the block above has failed to find a page to
+    ** recycle. In this case return early - no further memory will
+    ** be released.
+    */
+    if( !pPg ) break;
+
+    pPager = pPg->pPager;
+    assert(!pPg->needSync || pPg==pPager->lru.pFirst);
+    assert(pPg->needSync || pPg==pPager->lru.pFirstSynced);
+  
+    savedBusy = pPager->pBusyHandler;
+    pPager->pBusyHandler = 0;
+    rc = pager_recycle(pPager, &pRecycled);
+    pPager->pBusyHandler = savedBusy;
+    assert(pRecycled==pPg || rc!=SQLITE_OK);
+    if( rc==SQLITE_OK ){
+      /* We've found a page to free. At this point the page has been 
+      ** removed from the page hash-table, free-list and synced-list 
+      ** (pFirstSynced). It is still in the all pages (pAll) list. 
+      ** Remove it from this list before freeing.
+      **
+      ** Todo: Check the Pager.pStmt list to make sure this is Ok. It 
+      ** probably is though.
+      */
+      PgHdr *pTmp;
+      assert( pPg );
+      if( pPg==pPager->pAll ){
+         assert(pPg->pPrevAll==0);
+         assert(pPg->pNextAll==0 || pPg->pNextAll->pPrevAll==pPg);
+         pPager->pAll = pPg->pNextAll;
+         if( pPager->pAll ){
+           pPager->pAll->pPrevAll = 0;
+         }
+      }else{
+         assert(pPg->pPrevAll);
+         assert(pPg->pPrevAll->pNextAll==pPg);
+         pTmp = pPg->pPrevAll;
+         pTmp->pNextAll = pPg->pNextAll;
+         if( pTmp->pNextAll ){
+           pTmp->pNextAll->pPrevAll = pTmp;
+         }
+      }
+      nReleased += (
+          sizeof(*pPg) + pPager->pageSize
+          + sizeof(u32) + pPager->nExtra
+          + MEMDB*sizeof(PgHistory) 
+      );
+      IOTRACE(("PGFREE %p %d *\n", pPager, pPg->pgno));
+      PAGER_INCR(sqlite3_pager_pgfree_count);
+      sqlite3PageFree(pPg->pData);
+      sqlite3_free(pPg);
+      pPager->nPage--;
+    }else{
+      /* An error occured whilst writing to the database file or 
+      ** journal in pager_recycle(). The error is not returned to the 
+      ** caller of this function. Instead, set the Pager.errCode variable.
+      ** The error will be returned to the user (or users, in the case 
+      ** of a shared pager cache) of the pager for which the error occured.
+      */
+      assert(
+          (rc&0xff)==SQLITE_IOERR ||
+          rc==SQLITE_FULL ||
+          rc==SQLITE_BUSY
+      );
+      assert( pPager->state>=PAGER_RESERVED );
+      pager_error(pPager, rc);
+    }
+  }
+
+  /* Clear the memory management flags and release the mutex
+  */
+  for(pPager=sqlite3PagerList; pPager; pPager=pPager->pNext){
+     pPager->iInUseMM = 0;
+  }
+  sqlite3_mutex_leave(mutex);
+
+  /* Return the number of bytes released
+  */
+  return nReleased;
+}
+#endif /* SQLITE_ENABLE_MEMORY_MANAGEMENT */
+
+/*
+** Read the content of page pPg out of the database file.
+*/
+static int readDbPage(Pager *pPager, PgHdr *pPg, Pgno pgno){
+  int rc;
+  i64 offset;
+  assert( MEMDB==0 );
+  assert(pPager->fd->pMethods||pPager->tempFile);
+  if( !pPager->fd->pMethods ){
+    return SQLITE_IOERR_SHORT_READ;
+  }
+  offset = (pgno-1)*(i64)pPager->pageSize;
+  rc = sqlite3OsRead(pPager->fd, PGHDR_TO_DATA(pPg), pPager->pageSize, offset);
+  PAGER_INCR(sqlite3_pager_readdb_count);
+  PAGER_INCR(pPager->nRead);
+  IOTRACE(("PGIN %p %d\n", pPager, pgno));
+  if( pgno==1 ){
+    memcpy(&pPager->dbFileVers, &((u8*)PGHDR_TO_DATA(pPg))[24],
+                                              sizeof(pPager->dbFileVers));
+  }
+  CODEC1(pPager, PGHDR_TO_DATA(pPg), pPg->pgno, 3);
+  PAGERTRACE4("FETCH %d page %d hash(%08x)\n",
+               PAGERID(pPager), pPg->pgno, pager_pagehash(pPg));
+  return rc;
+}
+
+
+/*
+** This function is called to obtain the shared lock required before
+** data may be read from the pager cache. If the shared lock has already
+** been obtained, this function is a no-op.
+**
+** Immediately after obtaining the shared lock (if required), this function
+** checks for a hot-journal file. If one is found, an emergency rollback
+** is performed immediately.
+*/
+static int pagerSharedLock(Pager *pPager){
+  int rc = SQLITE_OK;
+  int isErrorReset = 0;
+
+  /* If this database is opened for exclusive access, has no outstanding 
+  ** page references and is in an error-state, now is the chance to clear
+  ** the error. Discard the contents of the pager-cache and treat any
+  ** open journal file as a hot-journal.
+  */
+  if( !MEMDB && pPager->exclusiveMode && pPager->nRef==0 && pPager->errCode ){
+    if( pPager->journalOpen ){
+      isErrorReset = 1;
+    }
+    pPager->errCode = SQLITE_OK;
+    pager_reset(pPager);
+  }
+
+  /* If the pager is still in an error state, do not proceed. The error 
+  ** state will be cleared at some point in the future when all page 
+  ** references are dropped and the cache can be discarded.
+  */
+  if( pPager->errCode && pPager->errCode!=SQLITE_FULL ){
+    return pPager->errCode;
+  }
+
+  if( pPager->state==PAGER_UNLOCK || isErrorReset ){
+    sqlite3_vfs *pVfs = pPager->pVfs;
+    if( !MEMDB ){
+      int isHotJournal;
+      assert( pPager->nRef==0 );
+      if( !pPager->noReadlock ){
+        rc = pager_wait_on_lock(pPager, SHARED_LOCK);
+        if( rc!=SQLITE_OK ){
+          assert( pPager->state==PAGER_UNLOCK );
+          return pager_error(pPager, rc);
+        }
+        assert( pPager->state>=SHARED_LOCK );
+      }
+  
+      /* If a journal file exists, and there is no RESERVED lock on the
+      ** database file, then it either needs to be played back or deleted.
+      */
+      if( !isErrorReset ){
+        rc = hasHotJournal(pPager, &isHotJournal);
+        if( rc!=SQLITE_OK ){
+          goto failed;
+        }
+      }
+      if( isErrorReset || isHotJournal ){
+        /* Get an EXCLUSIVE lock on the database file. At this point it is
+        ** important that a RESERVED lock is not obtained on the way to the
+        ** EXCLUSIVE lock. If it were, another process might open the
+        ** database file, detect the RESERVED lock, and conclude that the
+        ** database is safe to read while this process is still rolling it 
+        ** back.
+        ** 
+        ** Because the intermediate RESERVED lock is not requested, the
+        ** second process will get to this point in the code and fail to
+        ** obtain its own EXCLUSIVE lock on the database file.
+        */
+        if( pPager->state<EXCLUSIVE_LOCK ){
+          rc = sqlite3OsLock(pPager->fd, EXCLUSIVE_LOCK);
+          if( rc!=SQLITE_OK ){
+            rc = pager_error(pPager, rc);
+            goto failed;
+          }
+          pPager->state = PAGER_EXCLUSIVE;
+        }
+ 
+        /* Open the journal for read/write access. This is because in 
+        ** exclusive-access mode the file descriptor will be kept open and
+        ** possibly used for a transaction later on. On some systems, the
+        ** OsTruncate() call used in exclusive-access mode also requires
+        ** a read/write file handle.
+        */
+        if( !isErrorReset && pPager->journalOpen==0 ){
+          int res;
+          rc = sqlite3OsAccess(pVfs,pPager->zJournal,SQLITE_ACCESS_EXISTS,&res);
+          if( rc==SQLITE_OK ){
+            if( res ){
+              int fout = 0;
+              int f = SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_JOURNAL;
+              assert( !pPager->tempFile );
+              rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &fout);
+              assert( rc!=SQLITE_OK || pPager->jfd->pMethods );
+              if( fout&SQLITE_OPEN_READONLY ){
+                rc = SQLITE_BUSY;
+                sqlite3OsClose(pPager->jfd);
+              }
+            }else{
+              /* If the journal does not exist, that means some other process
+              ** has already rolled it back */
+              rc = SQLITE_BUSY;
+            }
+          }
+        }
+        if( rc!=SQLITE_OK ){
+          if( rc!=SQLITE_NOMEM && rc!=SQLITE_IOERR_UNLOCK 
+           && rc!=SQLITE_IOERR_NOMEM 
+          ){
+            rc = SQLITE_BUSY;
+          }
+          goto failed;
+        }
+        pPager->journalOpen = 1;
+        pPager->journalStarted = 0;
+        pPager->journalOff = 0;
+        pPager->setMaster = 0;
+        pPager->journalHdr = 0;
+ 
+        /* Playback and delete the journal.  Drop the database write
+        ** lock and reacquire the read lock.
+        */
+        rc = pager_playback(pPager, 1);
+        if( rc!=SQLITE_OK ){
+          rc = pager_error(pPager, rc);
+          goto failed;
+        }
+        assert(pPager->state==PAGER_SHARED || 
+            (pPager->exclusiveMode && pPager->state>PAGER_SHARED)
+        );
+      }
+
+      if( pPager->pAll ){
+        /* The shared-lock has just been acquired on the database file
+        ** and there are already pages in the cache (from a previous
+        ** read or write transaction).  Check to see if the database
+        ** has been modified.  If the database has changed, flush the
+        ** cache.
+        **
+        ** Database changes is detected by looking at 15 bytes beginning
+        ** at offset 24 into the file.  The first 4 of these 16 bytes are
+        ** a 32-bit counter that is incremented with each change.  The
+        ** other bytes change randomly with each file change when
+        ** a codec is in use.
+        ** 
+        ** There is a vanishingly small chance that a change will not be 
+        ** detected.  The chance of an undetected change is so small that
+        ** it can be neglected.
+        */
+        char dbFileVers[sizeof(pPager->dbFileVers)];
+        sqlite3PagerPagecount(pPager, 0);
+
+        if( pPager->errCode ){
+          rc = pPager->errCode;
+          goto failed;
+        }
+
+        if( pPager->dbSize>0 ){
+          IOTRACE(("CKVERS %p %d\n", pPager, sizeof(dbFileVers)));
+          rc = sqlite3OsRead(pPager->fd, &dbFileVers, sizeof(dbFileVers), 24);
+          if( rc!=SQLITE_OK ){
+            goto failed;
+          }
+        }else{
+          memset(dbFileVers, 0, sizeof(dbFileVers));
+        }
+
+        if( memcmp(pPager->dbFileVers, dbFileVers, sizeof(dbFileVers))!=0 ){
+          pager_reset(pPager);
+        }
+      }
+    }
+    assert( pPager->exclusiveMode || pPager->state<=PAGER_SHARED );
+    if( pPager->state==PAGER_UNLOCK ){
+      pPager->state = PAGER_SHARED;
+    }
+  }
+
+ failed:
+  if( rc!=SQLITE_OK ){
+    /* pager_unlock() is a no-op for exclusive mode and in-memory databases. */
+    pager_unlock(pPager);
+  }
+  return rc;
+}
+
+/*
+** Allocate a PgHdr object.   Either create a new one or reuse
+** an existing one that is not otherwise in use.
+**
+** A new PgHdr structure is created if any of the following are
+** true:
+**
+**     (1)  We have not exceeded our maximum allocated cache size
+**          as set by the "PRAGMA cache_size" command.
+**
+**     (2)  There are no unused PgHdr objects available at this time.
+**
+**     (3)  This is an in-memory database.
+**
+**     (4)  There are no PgHdr objects that do not require a journal
+**          file sync and a sync of the journal file is currently
+**          prohibited.
+**
+** Otherwise, reuse an existing PgHdr.  In other words, reuse an
+** existing PgHdr if all of the following are true:
+**
+**     (1)  We have reached or exceeded the maximum cache size
+**          allowed by "PRAGMA cache_size".
+**
+**     (2)  There is a PgHdr available with PgHdr->nRef==0
+**
+**     (3)  We are not in an in-memory database
+**
+**     (4)  Either there is an available PgHdr that does not need
+**          to be synced to disk or else disk syncing is currently
+**          allowed.
+*/
+static int pagerAllocatePage(Pager *pPager, PgHdr **ppPg){
+  int rc = SQLITE_OK;
+  PgHdr *pPg;
+  int nByteHdr;
+
+  /* Create a new PgHdr if any of the four conditions defined 
+  ** above are met: */
+  if( pPager->nPage<pPager->mxPage
+   || pPager->lru.pFirst==0 
+   || MEMDB
+   || (pPager->lru.pFirstSynced==0 && pPager->doNotSync)
+  ){
+    void *pData;
+    if( pPager->nPage>=pPager->nHash ){
+      pager_resize_hash_table(pPager,
+         pPager->nHash<256 ? 256 : pPager->nHash*2);
+      if( pPager->nHash==0 ){
+        rc = SQLITE_NOMEM;
+        goto pager_allocate_out;
+      }
+    }
+    pagerLeave(pPager);
+    nByteHdr = sizeof(*pPg) + sizeof(u32) + pPager->nExtra
+              + MEMDB*sizeof(PgHistory);
+    pPg = sqlite3Malloc( nByteHdr );
+    if( pPg ){
+      pData = sqlite3PageMalloc( pPager->pageSize );
+      if( pData==0 ){
+        sqlite3_free(pPg);
+        pPg = 0;
+      }
+    }
+    pagerEnter(pPager);
+    if( pPg==0 ){
+      rc = SQLITE_NOMEM;
+      goto pager_allocate_out;
+    }
+    memset(pPg, 0, nByteHdr);
+    pPg->pData = pData;
+    pPg->pPager = pPager;
+    pPg->pNextAll = pPager->pAll;
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+    if( pPg->pNextAll ){
+      pPg->pNextAll->pPrevAll = pPg;
+    }
+#endif
+    pPager->pAll = pPg;
+    pPager->nPage++;
+  }else{
+    /* Recycle an existing page with a zero ref-count. */
+    rc = pager_recycle(pPager, &pPg);
+    if( rc==SQLITE_BUSY ){
+      rc = SQLITE_IOERR_BLOCKED;
+    }
+    if( rc!=SQLITE_OK ){
+      goto pager_allocate_out;
+    }
+    assert( pPager->state>=SHARED_LOCK );
+    assert(pPg);
+  }
+  *ppPg = pPg;
+
+pager_allocate_out:
+  return rc;
+}
+
+/*
+** Make sure we have the content for a page.  If the page was
+** previously acquired with noContent==1, then the content was
+** just initialized to zeros instead of being read from disk.
+** But now we need the real data off of disk.  So make sure we
+** have it.  Read it in if we do not have it already.
+*/
+static int pager_get_content(PgHdr *pPg){
+  if( pPg->needRead ){
+    int rc = readDbPage(pPg->pPager, pPg, pPg->pgno);
+    if( rc==SQLITE_OK ){
+      pPg->needRead = 0;
+    }else{
+      return rc;
+    }
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Acquire a page.
+**
+** A read lock on the disk file is obtained when the first page is acquired. 
+** This read lock is dropped when the last page is released.
+**
+** This routine works for any page number greater than 0.  If the database
+** file is smaller than the requested page, then no actual disk
+** read occurs and the memory image of the page is initialized to
+** all zeros.  The extra data appended to a page is always initialized
+** to zeros the first time a page is loaded into memory.
+**
+** The acquisition might fail for several reasons.  In all cases,
+** an appropriate error code is returned and *ppPage is set to NULL.
+**
+** See also sqlite3PagerLookup().  Both this routine and Lookup() attempt
+** to find a page in the in-memory cache first.  If the page is not already
+** in memory, this routine goes to disk to read it in whereas Lookup()
+** just returns 0.  This routine acquires a read-lock the first time it
+** has to go to disk, and could also playback an old journal if necessary.
+** Since Lookup() never goes to disk, it never has to deal with locks
+** or journal files.
+**
+** If noContent is false, the page contents are actually read from disk.
+** If noContent is true, it means that we do not care about the contents
+** of the page at this time, so do not do a disk read.  Just fill in the
+** page content with zeros.  But mark the fact that we have not read the
+** content by setting the PgHdr.needRead flag.  Later on, if 
+** sqlite3PagerWrite() is called on this page or if this routine is
+** called again with noContent==0, that means that the content is needed
+** and the disk read should occur at that point.
+*/
+static int pagerAcquire(
+  Pager *pPager,      /* The pager open on the database file */
+  Pgno pgno,          /* Page number to fetch */
+  DbPage **ppPage,    /* Write a pointer to the page here */
+  int noContent       /* Do not bother reading content from disk if true */
+){
+  /* This just passes through to our modified version with NULL data. */
+  return sqlite3PagerAcquire2(pPager, pgno, ppPage, noContent, 0);
+}
+
+/*
+** This is an internal version of sqlite3PagerAcquire that takes an extra
+** parameter of data to use to fill the page with. This allows more efficient
+** filling for preloaded data. If this extra parameter is NULL, we'll go to
+** the file.
+**
+** See sqlite3PagerLoadall which uses this function.
+*/
+int sqlite3PagerAcquire2(
+  Pager *pPager,      /* The pager open on the database file */
+  Pgno pgno,          /* Page number to fetch */
+  DbPage **ppPage,    /* Write a pointer to the page here */
+  int noContent,      /* Do not bother reading content from disk if true */
+  unsigned char* pDataToFill
+){
+  PgHdr *pPg;
+  int rc;
+
+  assert( pPager->state==PAGER_UNLOCK || pPager->nRef>0 || pgno==1 );
+
+  /* The maximum page number is 2^31. Return SQLITE_CORRUPT if a page
+  ** number greater than this, or zero, is requested.
+  */
+  if( pgno>PAGER_MAX_PGNO || pgno==0 || pgno==PAGER_MJ_PGNO(pPager) ){
+    return SQLITE_CORRUPT_BKPT;
+  }
+
+  /* Make sure we have not hit any critical errors.
+  */ 
+  assert( pPager!=0 );
+  *ppPage = 0;
+
+  /* If this is the first page accessed, then get a SHARED lock
+  ** on the database file. pagerSharedLock() is a no-op if 
+  ** a database lock is already held.
+  */
+  rc = pagerSharedLock(pPager);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+  assert( pPager->state!=PAGER_UNLOCK );
+
+  pPg = pager_lookup(pPager, pgno);
+  if( pPg==0 ){
+    /* The requested page is not in the page cache. */
+    int nMax;
+    int h;
+    PAGER_INCR(pPager->nMiss);
+    rc = pagerAllocatePage(pPager, &pPg);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+
+    pPg->pgno = pgno;
+    assert( !MEMDB || pgno>pPager->stmtSize );
+    pPg->inJournal = sqlite3BitvecTest(pPager->pInJournal, pgno);
+    pPg->needSync = 0;
+
+    makeClean(pPg);
+    pPg->nRef = 1;
+
+    pPager->nRef++;
+    if( pPager->nExtra>0 ){
+      memset(PGHDR_TO_EXTRA(pPg, pPager), 0, pPager->nExtra);
+    }
+    rc = sqlite3PagerPagecount(pPager, &nMax);
+    if( rc!=SQLITE_OK ){
+      sqlite3PagerUnref(pPg);
+      return rc;
+    }
+
+    /* Populate the page with data, either by reading from the database
+    ** file, or by setting the entire page to zero.
+    */
+    if( nMax<(int)pgno || MEMDB || (noContent && !pPager->alwaysRollback) ){
+      if( pgno>pPager->mxPgno ){
+        sqlite3PagerUnref(pPg);
+        return SQLITE_FULL;
+      }
+      memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
+      pPg->needRead = noContent && !pPager->alwaysRollback;
+      IOTRACE(("ZERO %p %d\n", pPager, pgno));
+    }else{
+      if (pDataToFill) {
+        /* Just copy from the given memory. */
+        memcpy(PGHDR_TO_DATA(pPg), pDataToFill, pPager->pageSize);
+        CODEC1(pPager, PGHDR_TO_DATA(pPg), pPg->pgno, 3);
+      } else {
+        /* Load from disk (old regular sqlite code path). */
+        rc = readDbPage(pPager, pPg, pgno);
+        if( rc!=SQLITE_OK && rc!=SQLITE_IOERR_SHORT_READ ){
+          pPg->pgno = 0;
+          sqlite3PagerUnref(pPg);
+          return rc;
+        }
+      }
+      pPg->needRead = 0;
+    }
+
+    /* Link the page into the page hash table */
+    h = pgno & (pPager->nHash-1);
+    assert( pgno!=0 );
+    pPg->pNextHash = pPager->aHash[h];
+    pPager->aHash[h] = pPg;
+    if( pPg->pNextHash ){
+      assert( pPg->pNextHash->pPrevHash==0 );
+      pPg->pNextHash->pPrevHash = pPg;
+    }
+
+#ifdef SQLITE_CHECK_PAGES
+    pPg->pageHash = pager_pagehash(pPg);
+#endif
+  }else{
+    /* The requested page is in the page cache. */
+    assert(pPager->nRef>0 || pgno==1);
+    PAGER_INCR(pPager->nHit);
+    if( !noContent ){
+      rc = pager_get_content(pPg);
+      if( rc ){
+        return rc;
+      }
+    }
+    page_ref(pPg);
+  }
+  *ppPage = pPg;
+  return SQLITE_OK;
+}
+int sqlite3PagerAcquire(
+  Pager *pPager,      /* The pager open on the database file */
+  Pgno pgno,          /* Page number to fetch */
+  DbPage **ppPage,    /* Write a pointer to the page here */
+  int noContent       /* Do not bother reading content from disk if true */
+){
+  int rc;
+  pagerEnter(pPager);
+  rc = pagerAcquire(pPager, pgno, ppPage, noContent);
+  pagerLeave(pPager);
+  return rc;
+}
+
+
+/*
+** Acquire a page if it is already in the in-memory cache.  Do
+** not read the page from disk.  Return a pointer to the page,
+** or 0 if the page is not in cache.
+**
+** See also sqlite3PagerGet().  The difference between this routine
+** and sqlite3PagerGet() is that _get() will go to the disk and read
+** in the page if the page is not already in cache.  This routine
+** returns NULL if the page is not in cache or if a disk I/O error 
+** has ever happened.
+*/
+DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno){
+  PgHdr *pPg = 0;
+
+  assert( pPager!=0 );
+  assert( pgno!=0 );
+
+  pagerEnter(pPager);
+  if( pPager->state==PAGER_UNLOCK ){
+    assert( !pPager->pAll || pPager->exclusiveMode );
+  }else if( pPager->errCode && pPager->errCode!=SQLITE_FULL ){
+    /* Do nothing */
+  }else if( (pPg = pager_lookup(pPager, pgno))!=0 ){
+    page_ref(pPg);
+  }
+  pagerLeave(pPager);
+  return pPg;
+}
+
+/*
+** Release a page.
+**
+** If the number of references to the page drop to zero, then the
+** page is added to the LRU list.  When all references to all pages
+** are released, a rollback occurs and the lock on the database is
+** removed.
+*/
+int sqlite3PagerUnref(DbPage *pPg){
+  Pager *pPager;
+
+  if( pPg==0 ) return SQLITE_OK;
+  pPager = pPg->pPager;
+
+  /* Decrement the reference count for this page
+  */
+  assert( pPg->nRef>0 );
+  pagerEnter(pPg->pPager);
+  pPg->nRef--;
+
+  CHECK_PAGE(pPg);
+
+  /* When the number of references to a page reach 0, call the
+  ** destructor and add the page to the freelist.
+  */
+  if( pPg->nRef==0 ){
+
+    lruListAdd(pPg);
+    if( pPager->xDestructor ){
+      pPager->xDestructor(pPg, pPager->pageSize);
+    }
+  
+    /* When all pages reach the freelist, drop the read lock from
+    ** the database file.
+    */
+    pPager->nRef--;
+    assert( pPager->nRef>=0 );
+    if( pPager->nRef==0 && (!pPager->exclusiveMode || pPager->journalOff>0) ){
+      pagerUnlockAndRollback(pPager);
+    }
+  }
+  pagerLeave(pPager);
+  return SQLITE_OK;
+}
+
+/*
+** Create a journal file for pPager.  There should already be a RESERVED
+** or EXCLUSIVE lock on the database file when this routine is called.
+**
+** Return SQLITE_OK if everything.  Return an error code and release the
+** write lock if anything goes wrong.
+*/
+static int pager_open_journal(Pager *pPager){
+  sqlite3_vfs *pVfs = pPager->pVfs;
+  int flags = (SQLITE_OPEN_READWRITE|SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_CREATE);
+
+  int rc;
+  assert( !MEMDB );
+  assert( pPager->state>=PAGER_RESERVED );
+  assert( pPager->useJournal );
+  assert( pPager->pInJournal==0 );
+  sqlite3PagerPagecount(pPager, 0);
+  pagerLeave(pPager);
+  pPager->pInJournal = sqlite3BitvecCreate(pPager->dbSize);
+  pagerEnter(pPager);
+  if( pPager->pInJournal==0 ){
+    rc = SQLITE_NOMEM;
+    goto failed_to_open_journal;
+  }
+
+  if( pPager->journalOpen==0 ){
+    if( pPager->tempFile ){
+      flags |= (SQLITE_OPEN_DELETEONCLOSE|SQLITE_OPEN_TEMP_JOURNAL);
+    }else{
+      flags |= (SQLITE_OPEN_MAIN_JOURNAL);
+    }
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+    rc = sqlite3JournalOpen(
+        pVfs, pPager->zJournal, pPager->jfd, flags, jrnlBufferSize(pPager)
+    );
+#else
+    rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, flags, 0);
+#endif
+    assert( rc!=SQLITE_OK || pPager->jfd->pMethods );
+    pPager->journalOff = 0;
+    pPager->setMaster = 0;
+    pPager->journalHdr = 0;
+    if( rc!=SQLITE_OK ){
+      if( rc==SQLITE_NOMEM ){
+        sqlite3OsDelete(pVfs, pPager->zJournal, 0);
+      }
+      goto failed_to_open_journal;
+    }
+  }
+  pPager->journalOpen = 1;
+  pPager->journalStarted = 0;
+  pPager->needSync = 0;
+  pPager->alwaysRollback = 0;
+  pPager->nRec = 0;
+  if( pPager->errCode ){
+    rc = pPager->errCode;
+    goto failed_to_open_journal;
+  }
+  pPager->origDbSize = pPager->dbSize;
+
+  rc = writeJournalHdr(pPager);
+
+  if( pPager->stmtAutoopen && rc==SQLITE_OK ){
+    rc = sqlite3PagerStmtBegin(pPager);
+  }
+  if( rc!=SQLITE_OK && rc!=SQLITE_NOMEM && rc!=SQLITE_IOERR_NOMEM ){
+    rc = pager_end_transaction(pPager, 0);
+    if( rc==SQLITE_OK ){
+      rc = SQLITE_FULL;
+    }
+  }
+  return rc;
+
+failed_to_open_journal:
+  sqlite3BitvecDestroy(pPager->pInJournal);
+  pPager->pInJournal = 0;
+  return rc;
+}
+
+/*
+** Acquire a write-lock on the database.  The lock is removed when
+** the any of the following happen:
+**
+**   *  sqlite3PagerCommitPhaseTwo() is called.
+**   *  sqlite3PagerRollback() is called.
+**   *  sqlite3PagerClose() is called.
+**   *  sqlite3PagerUnref() is called to on every outstanding page.
+**
+** The first parameter to this routine is a pointer to any open page of the
+** database file.  Nothing changes about the page - it is used merely to
+** acquire a pointer to the Pager structure and as proof that there is
+** already a read-lock on the database.
+**
+** The second parameter indicates how much space in bytes to reserve for a
+** master journal file-name at the start of the journal when it is created.
+**
+** A journal file is opened if this is not a temporary file.  For temporary
+** files, the opening of the journal file is deferred until there is an
+** actual need to write to the journal.
+**
+** If the database is already reserved for writing, this routine is a no-op.
+**
+** If exFlag is true, go ahead and get an EXCLUSIVE lock on the file
+** immediately instead of waiting until we try to flush the cache.  The
+** exFlag is ignored if a transaction is already active.
+*/
+int sqlite3PagerBegin(DbPage *pPg, int exFlag){
+  Pager *pPager = pPg->pPager;
+  int rc = SQLITE_OK;
+  pagerEnter(pPager);
+  assert( pPg->nRef>0 );
+  assert( pPager->state!=PAGER_UNLOCK );
+  if( pPager->state==PAGER_SHARED ){
+    assert( pPager->pInJournal==0 );
+    if( MEMDB ){
+      pPager->state = PAGER_EXCLUSIVE;
+      pPager->origDbSize = pPager->dbSize;
+    }else{
+      rc = sqlite3OsLock(pPager->fd, RESERVED_LOCK);
+      if( rc==SQLITE_OK ){
+        pPager->state = PAGER_RESERVED;
+        if( exFlag ){
+          rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
+        }
+      }
+      if( rc!=SQLITE_OK ){
+        pagerLeave(pPager);
+        return rc;
+      }
+      pPager->dirtyCache = 0;
+      PAGERTRACE2("TRANSACTION %d\n", PAGERID(pPager));
+      if( pPager->useJournal && !pPager->tempFile
+             && pPager->journalMode!=PAGER_JOURNALMODE_OFF ){
+        rc = pager_open_journal(pPager);
+      }
+    }
+  }else if( pPager->journalOpen && pPager->journalOff==0 ){
+    /* This happens when the pager was in exclusive-access mode the last
+    ** time a (read or write) transaction was successfully concluded
+    ** by this connection. Instead of deleting the journal file it was 
+    ** kept open and either was truncated to 0 bytes or its header was
+    ** overwritten with zeros.
+    */
+    assert( pPager->nRec==0 );
+    assert( pPager->origDbSize==0 );
+    assert( pPager->pInJournal==0 );
+    sqlite3PagerPagecount(pPager, 0);
+    pagerLeave(pPager);
+    pPager->pInJournal = sqlite3BitvecCreate( pPager->dbSize );
+    pagerEnter(pPager);
+    if( !pPager->pInJournal ){
+      rc = SQLITE_NOMEM;
+    }else{
+      pPager->origDbSize = pPager->dbSize;
+      rc = writeJournalHdr(pPager);
+    }
+  }
+  assert( !pPager->journalOpen || pPager->journalOff>0 || rc!=SQLITE_OK );
+  pagerLeave(pPager);
+  return rc;
+}
+
+/*
+** Make a page dirty.  Set its dirty flag and add it to the dirty
+** page list.
+*/
+static void makeDirty(PgHdr *pPg){
+  if( pPg->dirty==0 ){
+    Pager *pPager = pPg->pPager;
+    pPg->dirty = 1;
+    pPg->pDirty = pPager->pDirty;
+    if( pPager->pDirty ){
+      pPager->pDirty->pPrevDirty = pPg;
+    }
+    pPg->pPrevDirty = 0;
+    pPager->pDirty = pPg;
+  }
+}
+
+/*
+** Make a page clean.  Clear its dirty bit and remove it from the
+** dirty page list.
+*/
+static void makeClean(PgHdr *pPg){
+  if( pPg->dirty ){
+    pPg->dirty = 0;
+    if( pPg->pDirty ){
+      assert( pPg->pDirty->pPrevDirty==pPg );
+      pPg->pDirty->pPrevDirty = pPg->pPrevDirty;
+    }
+    if( pPg->pPrevDirty ){
+      assert( pPg->pPrevDirty->pDirty==pPg );
+      pPg->pPrevDirty->pDirty = pPg->pDirty;
+    }else{
+      assert( pPg->pPager->pDirty==pPg );
+      pPg->pPager->pDirty = pPg->pDirty;
+    }
+  }
+}
+
+
+/*
+** Mark a data page as writeable.  The page is written into the journal 
+** if it is not there already.  This routine must be called before making
+** changes to a page.
+**
+** The first time this routine is called, the pager creates a new
+** journal and acquires a RESERVED lock on the database.  If the RESERVED
+** lock could not be acquired, this routine returns SQLITE_BUSY.  The
+** calling routine must check for that return value and be careful not to
+** change any page data until this routine returns SQLITE_OK.
+**
+** If the journal file could not be written because the disk is full,
+** then this routine returns SQLITE_FULL and does an immediate rollback.
+** All subsequent write attempts also return SQLITE_FULL until there
+** is a call to sqlite3PagerCommit() or sqlite3PagerRollback() to
+** reset.
+*/
+static int pager_write(PgHdr *pPg){
+  void *pData = PGHDR_TO_DATA(pPg);
+  Pager *pPager = pPg->pPager;
+  int rc = SQLITE_OK;
+
+  /* Check for errors
+  */
+  if( pPager->errCode ){ 
+    return pPager->errCode;
+  }
+  if( pPager->readOnly ){
+    return SQLITE_PERM;
+  }
+
+  assert( !pPager->setMaster );
+
+  CHECK_PAGE(pPg);
+
+  /* If this page was previously acquired with noContent==1, that means
+  ** we didn't really read in the content of the page.  This can happen
+  ** (for example) when the page is being moved to the freelist.  But
+  ** now we are (perhaps) moving the page off of the freelist for
+  ** reuse and we need to know its original content so that content
+  ** can be stored in the rollback journal.  So do the read at this
+  ** time.
+  */
+  rc = pager_get_content(pPg);
+  if( rc ){
+    return rc;
+  }
+
+  /* Mark the page as dirty.  If the page has already been written
+  ** to the journal then we can return right away.
+  */
+  makeDirty(pPg);
+  if( pPg->inJournal && (pageInStatement(pPg) || pPager->stmtInUse==0) ){
+    pPager->dirtyCache = 1;
+    pPager->dbModified = 1;
+  }else{
+
+    /* If we get this far, it means that the page needs to be
+    ** written to the transaction journal or the ckeckpoint journal
+    ** or both.
+    **
+    ** First check to see that the transaction journal exists and
+    ** create it if it does not.
+    */
+    assert( pPager->state!=PAGER_UNLOCK );
+    rc = sqlite3PagerBegin(pPg, 0);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    assert( pPager->state>=PAGER_RESERVED );
+    if( !pPager->journalOpen && pPager->useJournal
+          && pPager->journalMode!=PAGER_JOURNALMODE_OFF ){
+      rc = pager_open_journal(pPager);
+      if( rc!=SQLITE_OK ) return rc;
+    }
+    pPager->dirtyCache = 1;
+    pPager->dbModified = 1;
+  
+    /* The transaction journal now exists and we have a RESERVED or an
+    ** EXCLUSIVE lock on the main database file.  Write the current page to
+    ** the transaction journal if it is not there already.
+    */
+    if( !pPg->inJournal && (pPager->journalOpen || MEMDB) ){
+      if( (int)pPg->pgno <= pPager->origDbSize ){
+        if( MEMDB ){
+          PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
+          PAGERTRACE3("JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
+          assert( pHist->pOrig==0 );
+          pHist->pOrig = sqlite3PageMalloc( pPager->pageSize );
+          if( !pHist->pOrig ){
+            return SQLITE_NOMEM;
+          }
+          memcpy(pHist->pOrig, PGHDR_TO_DATA(pPg), pPager->pageSize);
+        }else{
+          u32 cksum;
+          char *pData2;
+
+          /* We should never write to the journal file the page that
+          ** contains the database locks.  The following assert verifies
+          ** that we do not. */
+          assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
+          pData2 = CODEC2(pPager, pData, pPg->pgno, 7);
+          cksum = pager_cksum(pPager, (u8*)pData2);
+          rc = write32bits(pPager->jfd, pPager->journalOff, pPg->pgno);
+          if( rc==SQLITE_OK ){
+            rc = sqlite3OsWrite(pPager->jfd, pData2, pPager->pageSize,
+                                pPager->journalOff + 4);
+            pPager->journalOff += pPager->pageSize+4;
+          }
+          if( rc==SQLITE_OK ){
+            rc = write32bits(pPager->jfd, pPager->journalOff, cksum);
+            pPager->journalOff += 4;
+          }
+          IOTRACE(("JOUT %p %d %lld %d\n", pPager, pPg->pgno, 
+                   pPager->journalOff, pPager->pageSize));
+          PAGER_INCR(sqlite3_pager_writej_count);
+          PAGERTRACE5("JOURNAL %d page %d needSync=%d hash(%08x)\n",
+               PAGERID(pPager), pPg->pgno, pPg->needSync, pager_pagehash(pPg));
+
+          /* An error has occured writing to the journal file. The 
+          ** transaction will be rolled back by the layer above.
+          */
+          if( rc!=SQLITE_OK ){
+            return rc;
+          }
+
+          pPager->nRec++;
+          assert( pPager->pInJournal!=0 );
+          sqlite3BitvecSet(pPager->pInJournal, pPg->pgno);
+          pPg->needSync = !pPager->noSync;
+          if( pPager->stmtInUse ){
+            sqlite3BitvecSet(pPager->pInStmt, pPg->pgno);
+          }
+        }
+      }else{
+        pPg->needSync = !pPager->journalStarted && !pPager->noSync;
+        PAGERTRACE4("APPEND %d page %d needSync=%d\n",
+                PAGERID(pPager), pPg->pgno, pPg->needSync);
+      }
+      if( pPg->needSync ){
+        pPager->needSync = 1;
+      }
+      pPg->inJournal = 1;
+    }
+  
+    /* If the statement journal is open and the page is not in it,
+    ** then write the current page to the statement journal.  Note that
+    ** the statement journal format differs from the standard journal format
+    ** in that it omits the checksums and the header.
+    */
+    if( pPager->stmtInUse 
+     && !pageInStatement(pPg) 
+     && (int)pPg->pgno<=pPager->stmtSize 
+    ){
+      assert( pPg->inJournal || (int)pPg->pgno>pPager->origDbSize );
+      if( MEMDB ){
+        PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
+        assert( pHist->pStmt==0 );
+        pHist->pStmt = sqlite3PageMalloc( pPager->pageSize );
+        if( pHist->pStmt ){
+          memcpy(pHist->pStmt, PGHDR_TO_DATA(pPg), pPager->pageSize);
+        }
+        PAGERTRACE3("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
+        page_add_to_stmt_list(pPg);
+      }else{
+        i64 offset = pPager->stmtNRec*(4+pPager->pageSize);
+        char *pData2 = CODEC2(pPager, pData, pPg->pgno, 7);
+        rc = write32bits(pPager->stfd, offset, pPg->pgno);
+        if( rc==SQLITE_OK ){
+          rc = sqlite3OsWrite(pPager->stfd, pData2, pPager->pageSize, offset+4);
+        }
+        PAGERTRACE3("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
+        if( rc!=SQLITE_OK ){
+          return rc;
+        }
+        pPager->stmtNRec++;
+        assert( pPager->pInStmt!=0 );
+        sqlite3BitvecSet(pPager->pInStmt, pPg->pgno);
+      }
+    }
+  }
+
+  /* Update the database size and return.
+  */
+  assert( pPager->state>=PAGER_SHARED );
+  if( pPager->dbSize<(int)pPg->pgno ){
+    pPager->dbSize = pPg->pgno;
+    if( !MEMDB && pPager->dbSize==PENDING_BYTE/pPager->pageSize ){
+      pPager->dbSize++;
+    }
+  }
+  return rc;
+}
+
+/*
+** This function is used to mark a data-page as writable. It uses 
+** pager_write() to open a journal file (if it is not already open)
+** and write the page *pData to the journal.
+**
+** The difference between this function and pager_write() is that this
+** function also deals with the special case where 2 or more pages
+** fit on a single disk sector. In this case all co-resident pages
+** must have been written to the journal file before returning.
+*/
+int sqlite3PagerWrite(DbPage *pDbPage){
+  int rc = SQLITE_OK;
+
+  PgHdr *pPg = pDbPage;
+  Pager *pPager = pPg->pPager;
+  Pgno nPagePerSector = (pPager->sectorSize/pPager->pageSize);
+
+  pagerEnter(pPager);
+  if( !MEMDB && nPagePerSector>1 ){
+    Pgno nPageCount;          /* Total number of pages in database file */
+    Pgno pg1;                 /* First page of the sector pPg is located on. */
+    int nPage;                /* Number of pages starting at pg1 to journal */
+    int ii;
+    int needSync = 0;
+
+    /* Set the doNotSync flag to 1. This is because we cannot allow a journal
+    ** header to be written between the pages journaled by this function.
+    */
+    assert( pPager->doNotSync==0 );
+    pPager->doNotSync = 1;
+
+    /* This trick assumes that both the page-size and sector-size are
+    ** an integer power of 2. It sets variable pg1 to the identifier
+    ** of the first page of the sector pPg is located on.
+    */
+    pg1 = ((pPg->pgno-1) & ~(nPagePerSector-1)) + 1;
+
+    sqlite3PagerPagecount(pPager, (int *)&nPageCount);
+    if( pPg->pgno>nPageCount ){
+      nPage = (pPg->pgno - pg1)+1;
+    }else if( (pg1+nPagePerSector-1)>nPageCount ){
+      nPage = nPageCount+1-pg1;
+    }else{
+      nPage = nPagePerSector;
+    }
+    assert(nPage>0);
+    assert(pg1<=pPg->pgno);
+    assert((pg1+nPage)>pPg->pgno);
+
+    for(ii=0; ii<nPage && rc==SQLITE_OK; ii++){
+      Pgno pg = pg1+ii;
+      PgHdr *pPage;
+      if( pg==pPg->pgno || !sqlite3BitvecTest(pPager->pInJournal, pg) ){
+        if( pg!=PAGER_MJ_PGNO(pPager) ){
+          rc = sqlite3PagerGet(pPager, pg, &pPage);
+          if( rc==SQLITE_OK ){
+            rc = pager_write(pPage);
+            if( pPage->needSync ){
+              needSync = 1;
+            }
+            sqlite3PagerUnref(pPage);
+          }
+        }
+      }else if( (pPage = pager_lookup(pPager, pg))!=0 ){
+        if( pPage->needSync ){
+          needSync = 1;
+        }
+      }
+    }
+
+    /* If the PgHdr.needSync flag is set for any of the nPage pages 
+    ** starting at pg1, then it needs to be set for all of them. Because
+    ** writing to any of these nPage pages may damage the others, the
+    ** journal file must contain sync()ed copies of all of them
+    ** before any of them can be written out to the database file.
+    */
+    if( needSync ){
+      for(ii=0; ii<nPage && needSync; ii++){
+        PgHdr *pPage = pager_lookup(pPager, pg1+ii);
+        if( pPage ) pPage->needSync = 1;
+      }
+      assert(pPager->needSync);
+    }
+
+    assert( pPager->doNotSync==1 );
+    pPager->doNotSync = 0;
+  }else{
+    rc = pager_write(pDbPage);
+  }
+  pagerLeave(pPager);
+  return rc;
+}
+
+/*
+** Return TRUE if the page given in the argument was previously passed
+** to sqlite3PagerWrite().  In other words, return TRUE if it is ok
+** to change the content of the page.
+*/
+#ifndef NDEBUG
+int sqlite3PagerIswriteable(DbPage *pPg){
+  return pPg->dirty;
+}
+#endif
+
+/*
+** A call to this routine tells the pager that it is not necessary to
+** write the information on page pPg back to the disk, even though
+** that page might be marked as dirty.
+**
+** The overlying software layer calls this routine when all of the data
+** on the given page is unused.  The pager marks the page as clean so
+** that it does not get written to disk.
+**
+** Tests show that this optimization, together with the
+** sqlite3PagerDontRollback() below, more than double the speed
+** of large INSERT operations and quadruple the speed of large DELETEs.
+**
+** When this routine is called, set the alwaysRollback flag to true.
+** Subsequent calls to sqlite3PagerDontRollback() for the same page
+** will thereafter be ignored.  This is necessary to avoid a problem
+** where a page with data is added to the freelist during one part of
+** a transaction then removed from the freelist during a later part
+** of the same transaction and reused for some other purpose.  When it
+** is first added to the freelist, this routine is called.  When reused,
+** the sqlite3PagerDontRollback() routine is called.  But because the
+** page contains critical data, we still need to be sure it gets
+** rolled back in spite of the sqlite3PagerDontRollback() call.
+*/
+void sqlite3PagerDontWrite(DbPage *pDbPage){
+  PgHdr *pPg = pDbPage;
+  Pager *pPager = pPg->pPager;
+
+  if( MEMDB ) return;
+  pagerEnter(pPager);
+  pPg->alwaysRollback = 1;
+  if( pPg->dirty && !pPager->stmtInUse ){
+    assert( pPager->state>=PAGER_SHARED );
+    if( pPager->dbSize==(int)pPg->pgno && pPager->origDbSize<pPager->dbSize ){
+      /* If this pages is the last page in the file and the file has grown
+      ** during the current transaction, then do NOT mark the page as clean.
+      ** When the database file grows, we must make sure that the last page
+      ** gets written at least once so that the disk file will be the correct
+      ** size. If you do not write this page and the size of the file
+      ** on the disk ends up being too small, that can lead to database
+      ** corruption during the next transaction.
+      */
+    }else{
+      PAGERTRACE3("DONT_WRITE page %d of %d\n", pPg->pgno, PAGERID(pPager));
+      IOTRACE(("CLEAN %p %d\n", pPager, pPg->pgno))
+      makeClean(pPg);
+#ifdef SQLITE_CHECK_PAGES
+      pPg->pageHash = pager_pagehash(pPg);
+#endif
+    }
+  }
+  pagerLeave(pPager);
+}
+
+/*
+** A call to this routine tells the pager that if a rollback occurs,
+** it is not necessary to restore the data on the given page.  This
+** means that the pager does not have to record the given page in the
+** rollback journal.
+**
+** If we have not yet actually read the content of this page (if
+** the PgHdr.needRead flag is set) then this routine acts as a promise
+** that we will never need to read the page content in the future.
+** so the needRead flag can be cleared at this point.
+*/
+void sqlite3PagerDontRollback(DbPage *pPg){
+  Pager *pPager = pPg->pPager;
+
+  pagerEnter(pPager);
+  assert( pPager->state>=PAGER_RESERVED );
+
+  /* If the journal file is not open, or DontWrite() has been called on
+  ** this page (DontWrite() sets the alwaysRollback flag), then this
+  ** function is a no-op.
+  */
+  if( pPager->journalOpen==0 || pPg->alwaysRollback || pPager->alwaysRollback ){
+    pagerLeave(pPager);
+    return;
+  }
+  assert( !MEMDB );    /* For a memdb, pPager->journalOpen is always 0 */
+
+#ifdef SQLITE_SECURE_DELETE
+  if( pPg->inJournal || (int)pPg->pgno > pPager->origDbSize ){
+    return;
+  }
+#endif
+
+  /* If SECURE_DELETE is disabled, then there is no way that this
+  ** routine can be called on a page for which sqlite3PagerDontWrite()
+  ** has not been previously called during the same transaction.
+  ** And if DontWrite() has previously been called, the following
+  ** conditions must be met.
+  **
+  ** (Later:)  Not true.  If the database is corrupted by having duplicate
+  ** pages on the freelist (ex: corrupt9.test) then the following is not
+  ** necessarily true:
+  */
+  /* assert( !pPg->inJournal && (int)pPg->pgno <= pPager->origDbSize ); */
+
+  assert( pPager->pInJournal!=0 );
+  sqlite3BitvecSet(pPager->pInJournal, pPg->pgno);
+  pPg->inJournal = 1;
+  pPg->needRead = 0;
+  if( pPager->stmtInUse ){
+    assert( pPager->stmtSize >= pPager->origDbSize );
+    sqlite3BitvecSet(pPager->pInStmt, pPg->pgno);
+  }
+  PAGERTRACE3("DONT_ROLLBACK page %d of %d\n", pPg->pgno, PAGERID(pPager));
+  IOTRACE(("GARBAGE %p %d\n", pPager, pPg->pgno))
+  pagerLeave(pPager);
+}
+
+
+/*
+** This routine is called to increment the database file change-counter,
+** stored at byte 24 of the pager file.
+*/
+static int pager_incr_changecounter(Pager *pPager, int isDirect){
+  PgHdr *pPgHdr;
+  u32 change_counter;
+  int rc = SQLITE_OK;
+
+#ifndef SQLITE_ENABLE_ATOMIC_WRITE
+  assert( isDirect==0 );  /* isDirect is only true for atomic writes */
+#endif
+  if( !pPager->changeCountDone ){
+    /* Open page 1 of the file for writing. */
+    rc = sqlite3PagerGet(pPager, 1, &pPgHdr);
+    if( rc!=SQLITE_OK ) return rc;
+
+    if( !isDirect ){
+      rc = sqlite3PagerWrite(pPgHdr);
+      if( rc!=SQLITE_OK ){
+        sqlite3PagerUnref(pPgHdr);
+        return rc;
+      }
+    }
+
+    /* Increment the value just read and write it back to byte 24. */
+    change_counter = sqlite3Get4byte((u8*)pPager->dbFileVers);
+    change_counter++;
+    put32bits(((char*)PGHDR_TO_DATA(pPgHdr))+24, change_counter);
+
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+    if( isDirect && pPager->fd->pMethods ){
+      const void *zBuf = PGHDR_TO_DATA(pPgHdr);
+      rc = sqlite3OsWrite(pPager->fd, zBuf, pPager->pageSize, 0);
+    }
+#endif
+
+    /* Release the page reference. */
+    sqlite3PagerUnref(pPgHdr);
+    pPager->changeCountDone = 1;
+  }
+  return rc;
+}
+
+/*
+** Sync the pager file to disk.
+*/
+int sqlite3PagerSync(Pager *pPager){
+  int rc;
+  pagerEnter(pPager);
+  rc = sqlite3OsSync(pPager->fd, pPager->sync_flags);
+  pagerLeave(pPager);
+  return rc;
+}
+
+/*
+** Sync the database file for the pager pPager. zMaster points to the name
+** of a master journal file that should be written into the individual
+** journal file. zMaster may be NULL, which is interpreted as no master
+** journal (a single database transaction).
+**
+** This routine ensures that the journal is synced, all dirty pages written
+** to the database file and the database file synced. The only thing that
+** remains to commit the transaction is to delete the journal file (or
+** master journal file if specified).
+**
+** Note that if zMaster==NULL, this does not overwrite a previous value
+** passed to an sqlite3PagerCommitPhaseOne() call.
+**
+** If parameter nTrunc is non-zero, then the pager file is truncated to
+** nTrunc pages (this is used by auto-vacuum databases).
+**
+** If the final parameter - noSync - is true, then the database file itself
+** is not synced. The caller must call sqlite3PagerSync() directly to
+** sync the database file before calling CommitPhaseTwo() to delete the
+** journal file in this case.
+*/
+int sqlite3PagerCommitPhaseOne(
+  Pager *pPager, 
+  const char *zMaster, 
+  Pgno nTrunc,
+  int noSync
+){
+  int rc = SQLITE_OK;
+
+  if( pPager->errCode ){
+    return pPager->errCode;
+  }
+
+  /* If no changes have been made, we can leave the transaction early.
+  */
+  if( pPager->dbModified==0 &&
+        (pPager->journalMode!=PAGER_JOURNALMODE_DELETE ||
+          pPager->exclusiveMode!=0) ){
+    assert( pPager->dirtyCache==0 || pPager->journalOpen==0 );
+    return SQLITE_OK;
+  }
+
+  PAGERTRACE4("DATABASE SYNC: File=%s zMaster=%s nTrunc=%d\n", 
+      pPager->zFilename, zMaster, nTrunc);
+  pagerEnter(pPager);
+
+  /* If this is an in-memory db, or no pages have been written to, or this
+  ** function has already been called, it is a no-op.
+  */
+  if( pPager->state!=PAGER_SYNCED && !MEMDB && pPager->dirtyCache ){
+    PgHdr *pPg;
+
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+    /* The atomic-write optimization can be used if all of the
+    ** following are true:
+    **
+    **    + The file-system supports the atomic-write property for
+    **      blocks of size page-size, and
+    **    + This commit is not part of a multi-file transaction, and
+    **    + Exactly one page has been modified and store in the journal file.
+    **
+    ** If the optimization can be used, then the journal file will never
+    ** be created for this transaction.
+    */
+    int useAtomicWrite = (
+        !zMaster && 
+        pPager->journalOpen &&
+        pPager->journalOff==jrnlBufferSize(pPager) && 
+        nTrunc==0 && 
+        (0==pPager->pDirty || 0==pPager->pDirty->pDirty)
+    );
+    assert( pPager->journalOpen || pPager->journalMode==PAGER_JOURNALMODE_OFF );
+    if( useAtomicWrite ){
+      /* Update the nRec field in the journal file. */
+      int offset = pPager->journalHdr + sizeof(aJournalMagic);
+      assert(pPager->nRec==1);
+      rc = write32bits(pPager->jfd, offset, pPager->nRec);
+
+      /* Update the db file change counter. The following call will modify
+      ** the in-memory representation of page 1 to include the updated
+      ** change counter and then write page 1 directly to the database
+      ** file. Because of the atomic-write property of the host file-system, 
+      ** this is safe.
+      */
+      if( rc==SQLITE_OK ){
+        rc = pager_incr_changecounter(pPager, 1);
+      }
+    }else{
+      rc = sqlite3JournalCreate(pPager->jfd);
+    }
+
+    if( !useAtomicWrite && rc==SQLITE_OK )
+#endif
+
+    /* If a master journal file name has already been written to the
+    ** journal file, then no sync is required. This happens when it is
+    ** written, then the process fails to upgrade from a RESERVED to an
+    ** EXCLUSIVE lock. The next time the process tries to commit the
+    ** transaction the m-j name will have already been written.
+    */
+    if( !pPager->setMaster ){
+      rc = pager_incr_changecounter(pPager, 0);
+      if( rc!=SQLITE_OK ) goto sync_exit;
+      if( pPager->journalMode!=PAGER_JOURNALMODE_OFF ){
+#ifndef SQLITE_OMIT_AUTOVACUUM
+        if( nTrunc!=0 ){
+          /* If this transaction has made the database smaller, then all pages
+          ** being discarded by the truncation must be written to the journal
+          ** file.
+          */
+          Pgno i;
+          int iSkip = PAGER_MJ_PGNO(pPager);
+          for( i=nTrunc+1; i<=pPager->origDbSize; i++ ){
+            if( !sqlite3BitvecTest(pPager->pInJournal, i) && i!=iSkip ){
+              rc = sqlite3PagerGet(pPager, i, &pPg);
+              if( rc!=SQLITE_OK ) goto sync_exit;
+              rc = sqlite3PagerWrite(pPg);
+              sqlite3PagerUnref(pPg);
+              if( rc!=SQLITE_OK ) goto sync_exit;
+            }
+          } 
+        }
+#endif
+        rc = writeMasterJournal(pPager, zMaster);
+        if( rc!=SQLITE_OK ) goto sync_exit;
+        rc = syncJournal(pPager);
+      }
+    }
+    if( rc!=SQLITE_OK ) goto sync_exit;
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    if( nTrunc!=0 ){
+      rc = sqlite3PagerTruncate(pPager, nTrunc);
+      if( rc!=SQLITE_OK ) goto sync_exit;
+    }
+#endif
+
+    /* Write all dirty pages to the database file */
+    pPg = pager_get_all_dirty_pages(pPager);
+    rc = pager_write_pagelist(pPg);
+    if( rc!=SQLITE_OK ){
+      assert( rc!=SQLITE_IOERR_BLOCKED );
+      /* The error might have left the dirty list all fouled up here,
+      ** but that does not matter because if the if the dirty list did
+      ** get corrupted, then the transaction will roll back and
+      ** discard the dirty list.  There is an assert in
+      ** pager_get_all_dirty_pages() that verifies that no attempt
+      ** is made to use an invalid dirty list.
+      */
+      goto sync_exit;
+    }
+    pPager->pDirty = 0;
+
+    /* Sync the database file. */
+    if( !pPager->noSync && !noSync ){
+      rc = sqlite3OsSync(pPager->fd, pPager->sync_flags);
+    }
+    IOTRACE(("DBSYNC %p\n", pPager))
+
+    pPager->state = PAGER_SYNCED;
+  }else if( MEMDB && nTrunc!=0 ){
+    rc = sqlite3PagerTruncate(pPager, nTrunc);
+  }
+
+sync_exit:
+  if( rc==SQLITE_IOERR_BLOCKED ){
+    /* pager_incr_changecounter() may attempt to obtain an exclusive
+     * lock to spill the cache and return IOERR_BLOCKED. But since 
+     * there is no chance the cache is inconsistent, it is
+     * better to return SQLITE_BUSY.
+     */
+    rc = SQLITE_BUSY;
+  }
+  pagerLeave(pPager);
+  return rc;
+}
+
+
+/*
+** Commit all changes to the database and release the write lock.
+**
+** If the commit fails for any reason, a rollback attempt is made
+** and an error code is returned.  If the commit worked, SQLITE_OK
+** is returned.
+*/
+int sqlite3PagerCommitPhaseTwo(Pager *pPager){
+  int rc;
+  PgHdr *pPg;
+
+  if( pPager->errCode ){
+    return pPager->errCode;
+  }
+  if( pPager->state<PAGER_RESERVED ){
+    return SQLITE_ERROR;
+  }
+  if( pPager->dbModified==0 &&
+        (pPager->journalMode!=PAGER_JOURNALMODE_DELETE ||
+          pPager->exclusiveMode!=0) ){
+    assert( pPager->dirtyCache==0 || pPager->journalOpen==0 );
+    return SQLITE_OK;
+  }
+  pagerEnter(pPager);
+  PAGERTRACE2("COMMIT %d\n", PAGERID(pPager));
+  if( MEMDB ){
+    pPg = pager_get_all_dirty_pages(pPager);
+    while( pPg ){
+      PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
+      clearHistory(pHist);
+      pPg->dirty = 0;
+      pPg->inJournal = 0;
+      pHist->inStmt = 0;
+      pPg->needSync = 0;
+      pHist->pPrevStmt = pHist->pNextStmt = 0;
+      pPg = pPg->pDirty;
+    }
+    pPager->pDirty = 0;
+#ifndef NDEBUG
+    for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
+      PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
+      assert( !pPg->alwaysRollback );
+      assert( !pHist->pOrig );
+      assert( !pHist->pStmt );
+    }
+#endif
+    pPager->pStmt = 0;
+    pPager->state = PAGER_SHARED;
+    pagerLeave(pPager);
+    return SQLITE_OK;
+  }
+  assert( pPager->state==PAGER_SYNCED || !pPager->dirtyCache );
+  rc = pager_end_transaction(pPager, pPager->setMaster);
+  rc = pager_error(pPager, rc);
+  pagerLeave(pPager);
+  return rc;
+}
+
+/*
+** Rollback all changes.  The database falls back to PAGER_SHARED mode.
+** All in-memory cache pages revert to their original data contents.
+** The journal is deleted.
+**
+** This routine cannot fail unless some other process is not following
+** the correct locking protocol or unless some other
+** process is writing trash into the journal file (SQLITE_CORRUPT) or
+** unless a prior malloc() failed (SQLITE_NOMEM).  Appropriate error
+** codes are returned for all these occasions.  Otherwise,
+** SQLITE_OK is returned.
+*/
+int sqlite3PagerRollback(Pager *pPager){
+  int rc;
+  PAGERTRACE2("ROLLBACK %d\n", PAGERID(pPager));
+  if( MEMDB ){
+    PgHdr *p;
+    for(p=pPager->pAll; p; p=p->pNextAll){
+      PgHistory *pHist;
+      assert( !p->alwaysRollback );
+      if( !p->dirty ){
+        assert( !((PgHistory *)PGHDR_TO_HIST(p, pPager))->pOrig );
+        assert( !((PgHistory *)PGHDR_TO_HIST(p, pPager))->pStmt );
+        continue;
+      }
+
+      pHist = PGHDR_TO_HIST(p, pPager);
+      if( pHist->pOrig ){
+        memcpy(PGHDR_TO_DATA(p), pHist->pOrig, pPager->pageSize);
+        PAGERTRACE3("ROLLBACK-PAGE %d of %d\n", p->pgno, PAGERID(pPager));
+      }else{
+        PAGERTRACE3("PAGE %d is clean on %d\n", p->pgno, PAGERID(pPager));
+      }
+      clearHistory(pHist);
+      p->dirty = 0;
+      p->inJournal = 0;
+      pHist->inStmt = 0;
+      pHist->pPrevStmt = pHist->pNextStmt = 0;
+      if( pPager->xReiniter ){
+        pPager->xReiniter(p, pPager->pageSize);
+      }
+    }
+    pPager->pDirty = 0;
+    pPager->pStmt = 0;
+    pPager->dbSize = pPager->origDbSize;
+    pager_truncate_cache(pPager);
+    pPager->stmtInUse = 0;
+    pPager->state = PAGER_SHARED;
+    return SQLITE_OK;
+  }
+
+  pagerEnter(pPager);
+  if( !pPager->dirtyCache || !pPager->journalOpen ){
+    rc = pager_end_transaction(pPager, pPager->setMaster);
+    pagerLeave(pPager);
+    return rc;
+  }
+
+  if( pPager->errCode && pPager->errCode!=SQLITE_FULL ){
+    if( pPager->state>=PAGER_EXCLUSIVE ){
+      pager_playback(pPager, 0);
+    }
+    pagerLeave(pPager);
+    return pPager->errCode;
+  }
+  if( pPager->state==PAGER_RESERVED ){
+    int rc2;
+    rc = pager_playback(pPager, 0);
+    rc2 = pager_end_transaction(pPager, pPager->setMaster);
+    if( rc==SQLITE_OK ){
+      rc = rc2;
+    }
+  }else{
+    rc = pager_playback(pPager, 0);
+  }
+  /* pager_reset(pPager); */
+  pPager->dbSize = -1;
+
+  /* If an error occurs during a ROLLBACK, we can no longer trust the pager
+  ** cache. So call pager_error() on the way out to make any error 
+  ** persistent.
+  */
+  rc = pager_error(pPager, rc);
+  pagerLeave(pPager);
+  return rc;
+}
+
+/*
+** Return TRUE if the database file is opened read-only.  Return FALSE
+** if the database is (in theory) writable.
+*/
+int sqlite3PagerIsreadonly(Pager *pPager){
+  return pPager->readOnly;
+}
+
+/*
+** Return the number of references to the pager.
+*/
+int sqlite3PagerRefcount(Pager *pPager){
+  return pPager->nRef;
+}
+
+#ifdef SQLITE_TEST
+/*
+** This routine is used for testing and analysis only.
+*/
+int *sqlite3PagerStats(Pager *pPager){
+  static int a[11];
+  a[0] = pPager->nRef;
+  a[1] = pPager->nPage;
+  a[2] = pPager->mxPage;
+  a[3] = pPager->dbSize;
+  a[4] = pPager->state;
+  a[5] = pPager->errCode;
+  a[6] = pPager->nHit;
+  a[7] = pPager->nMiss;
+  a[8] = 0;  /* Used to be pPager->nOvfl */
+  a[9] = pPager->nRead;
+  a[10] = pPager->nWrite;
+  return a;
+}
+int sqlite3PagerIsMemdb(Pager *pPager){
+  return MEMDB;
+}
+#endif
+
+/*
+** Set the statement rollback point.
+**
+** This routine should be called with the transaction journal already
+** open.  A new statement journal is created that can be used to rollback
+** changes of a single SQL command within a larger transaction.
+*/
+static int pagerStmtBegin(Pager *pPager){
+  int rc;
+  assert( !pPager->stmtInUse );
+  assert( pPager->state>=PAGER_SHARED );
+  assert( pPager->dbSize>=0 );
+  PAGERTRACE2("STMT-BEGIN %d\n", PAGERID(pPager));
+  if( MEMDB ){
+    pPager->stmtInUse = 1;
+    pPager->stmtSize = pPager->dbSize;
+    return SQLITE_OK;
+  }
+  if( !pPager->journalOpen ){
+    pPager->stmtAutoopen = 1;
+    return SQLITE_OK;
+  }
+  assert( pPager->journalOpen );
+  pagerLeave(pPager);
+  assert( pPager->pInStmt==0 );
+  pPager->pInStmt = sqlite3BitvecCreate(pPager->dbSize);
+  pagerEnter(pPager);
+  if( pPager->pInStmt==0 ){
+    /* sqlite3OsLock(pPager->fd, SHARED_LOCK); */
+    return SQLITE_NOMEM;
+  }
+  pPager->stmtJSize = pPager->journalOff;
+  pPager->stmtSize = pPager->dbSize;
+  pPager->stmtHdrOff = 0;
+  pPager->stmtCksum = pPager->cksumInit;
+  if( !pPager->stmtOpen ){
+    rc = sqlite3PagerOpentemp(pPager, pPager->stfd, SQLITE_OPEN_SUBJOURNAL);
+    if( rc ){
+      goto stmt_begin_failed;
+    }
+    pPager->stmtOpen = 1;
+    pPager->stmtNRec = 0;
+  }
+  pPager->stmtInUse = 1;
+  return SQLITE_OK;
+ 
+stmt_begin_failed:
+  if( pPager->pInStmt ){
+    sqlite3BitvecDestroy(pPager->pInStmt);
+    pPager->pInStmt = 0;
+  }
+  return rc;
+}
+int sqlite3PagerStmtBegin(Pager *pPager){
+  int rc;
+  pagerEnter(pPager);
+  rc = pagerStmtBegin(pPager);
+  pagerLeave(pPager);
+  return rc;
+}
+
+/*
+** Commit a statement.
+*/
+int sqlite3PagerStmtCommit(Pager *pPager){
+  pagerEnter(pPager);
+  if( pPager->stmtInUse ){
+    PgHdr *pPg, *pNext;
+    PAGERTRACE2("STMT-COMMIT %d\n", PAGERID(pPager));
+    if( !MEMDB ){
+      /* sqlite3OsTruncate(pPager->stfd, 0); */
+      sqlite3BitvecDestroy(pPager->pInStmt);
+      pPager->pInStmt = 0;
+    }else{
+      for(pPg=pPager->pStmt; pPg; pPg=pNext){
+        PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
+        pNext = pHist->pNextStmt;
+        assert( pHist->inStmt );
+        pHist->inStmt = 0;
+        pHist->pPrevStmt = pHist->pNextStmt = 0;
+        sqlite3PageFree(pHist->pStmt);
+        pHist->pStmt = 0;
+      }
+    }
+    pPager->stmtNRec = 0;
+    pPager->stmtInUse = 0;
+    pPager->pStmt = 0;
+  }
+  pPager->stmtAutoopen = 0;
+  pagerLeave(pPager);
+  return SQLITE_OK;
+}
+
+/*
+** Rollback a statement.
+*/
+int sqlite3PagerStmtRollback(Pager *pPager){
+  int rc;
+  pagerEnter(pPager);
+  if( pPager->stmtInUse ){
+    PAGERTRACE2("STMT-ROLLBACK %d\n", PAGERID(pPager));
+    if( MEMDB ){
+      PgHdr *pPg;
+      PgHistory *pHist;
+      for(pPg=pPager->pStmt; pPg; pPg=pHist->pNextStmt){
+        pHist = PGHDR_TO_HIST(pPg, pPager);
+        if( pHist->pStmt ){
+          memcpy(PGHDR_TO_DATA(pPg), pHist->pStmt, pPager->pageSize);
+          sqlite3PageFree(pHist->pStmt);
+          pHist->pStmt = 0;
+        }
+      }
+      pPager->dbSize = pPager->stmtSize;
+      pager_truncate_cache(pPager);
+      rc = SQLITE_OK;
+    }else{
+      rc = pager_stmt_playback(pPager);
+    }
+    sqlite3PagerStmtCommit(pPager);
+  }else{
+    rc = SQLITE_OK;
+  }
+  pPager->stmtAutoopen = 0;
+  pagerLeave(pPager);
+  return rc;
+}
+
+/*
+** Return the full pathname of the database file.
+*/
+const char *sqlite3PagerFilename(Pager *pPager){
+  return pPager->zFilename;
+}
+
+/*
+** Return the VFS structure for the pager.
+*/
+const sqlite3_vfs *sqlite3PagerVfs(Pager *pPager){
+  return pPager->pVfs;
+}
+
+/*
+** Return the file handle for the database file associated
+** with the pager.  This might return NULL if the file has
+** not yet been opened.
+*/
+sqlite3_file *sqlite3PagerFile(Pager *pPager){
+  return pPager->fd;
+}
+
+/*
+** Return the directory of the database file.
+*/
+const char *sqlite3PagerDirname(Pager *pPager){
+  return pPager->zDirectory;
+}
+
+/*
+** Return the full pathname of the journal file.
+*/
+const char *sqlite3PagerJournalname(Pager *pPager){
+  return pPager->zJournal;
+}
+
+/*
+** Return true if fsync() calls are disabled for this pager.  Return FALSE
+** if fsync()s are executed normally.
+*/
+int sqlite3PagerNosync(Pager *pPager){
+  return pPager->noSync;
+}
+
+#ifdef SQLITE_HAS_CODEC
+/*
+** Set the codec for this pager
+*/
+void sqlite3PagerSetCodec(
+  Pager *pPager,
+  void *(*xCodec)(void*,void*,Pgno,int),
+  void *pCodecArg
+){
+  pPager->xCodec = xCodec;
+  pPager->pCodecArg = pCodecArg;
+}
+#endif
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+/*
+** Move the page pPg to location pgno in the file.
+**
+** There must be no references to the page previously located at
+** pgno (which we call pPgOld) though that page is allowed to be
+** in cache.  If the page previous located at pgno is not already
+** in the rollback journal, it is not put there by by this routine.
+**
+** References to the page pPg remain valid. Updating any
+** meta-data associated with pPg (i.e. data stored in the nExtra bytes
+** allocated along with the page) is the responsibility of the caller.
+**
+** A transaction must be active when this routine is called. It used to be
+** required that a statement transaction was not active, but this restriction
+** has been removed (CREATE INDEX needs to move a page when a statement
+** transaction is active).
+**
+** If the fourth argument, isCommit, is non-zero, then this page is being
+** moved as part of a database reorganization just before the transaction 
+** is being committed. In this case, it is guaranteed that the database page 
+** pPg refers to will not be written to again within this transaction.
+*/
+int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, int isCommit){
+  PgHdr *pPgOld;  /* The page being overwritten. */
+  int h;
+  Pgno needSyncPgno = 0;
+
+  pagerEnter(pPager);
+  assert( pPg->nRef>0 );
+
+  PAGERTRACE5("MOVE %d page %d (needSync=%d) moves to %d\n", 
+      PAGERID(pPager), pPg->pgno, pPg->needSync, pgno);
+  IOTRACE(("MOVE %p %d %d\n", pPager, pPg->pgno, pgno))
+
+  pager_get_content(pPg);
+
+  /* If the journal needs to be sync()ed before page pPg->pgno can
+  ** be written to, store pPg->pgno in local variable needSyncPgno.
+  **
+  ** If the isCommit flag is set, there is no need to remember that
+  ** the journal needs to be sync()ed before database page pPg->pgno 
+  ** can be written to. The caller has already promised not to write to it.
+  */
+  if( pPg->needSync && !isCommit ){
+    needSyncPgno = pPg->pgno;
+    assert( pPg->inJournal || (int)pgno>pPager->origDbSize );
+    assert( pPg->dirty );
+    assert( pPager->needSync );
+  }
+
+  /* Unlink pPg from its hash-chain */
+  unlinkHashChain(pPager, pPg);
+
+  /* If the cache contains a page with page-number pgno, remove it
+  ** from its hash chain. Also, if the PgHdr.needSync was set for 
+  ** page pgno before the 'move' operation, it needs to be retained 
+  ** for the page moved there.
+  */
+  pPg->needSync = 0;
+  pPgOld = pager_lookup(pPager, pgno);
+  if( pPgOld ){
+    assert( pPgOld->nRef==0 );
+    unlinkHashChain(pPager, pPgOld);
+    makeClean(pPgOld);
+    pPg->needSync = pPgOld->needSync;
+  }else{
+    pPg->needSync = 0;
+  }
+  pPg->inJournal = sqlite3BitvecTest(pPager->pInJournal, pgno);
+
+  /* Change the page number for pPg and insert it into the new hash-chain. */
+  assert( pgno!=0 );
+  pPg->pgno = pgno;
+  h = pgno & (pPager->nHash-1);
+  if( pPager->aHash[h] ){
+    assert( pPager->aHash[h]->pPrevHash==0 );
+    pPager->aHash[h]->pPrevHash = pPg;
+  }
+  pPg->pNextHash = pPager->aHash[h];
+  pPager->aHash[h] = pPg;
+  pPg->pPrevHash = 0;
+
+  makeDirty(pPg);
+  pPager->dirtyCache = 1;
+  pPager->dbModified = 1;
+
+  if( needSyncPgno ){
+    /* If needSyncPgno is non-zero, then the journal file needs to be 
+    ** sync()ed before any data is written to database file page needSyncPgno.
+    ** Currently, no such page exists in the page-cache and the 
+    ** "is journaled" bitvec flag has been set. This needs to be remedied by
+    ** loading the page into the pager-cache and setting the PgHdr.needSync 
+    ** flag.
+    **
+    ** If the attempt to load the page into the page-cache fails, (due
+    ** to a malloc() or IO failure), clear the bit in the pInJournal[]
+    ** array. Otherwise, if the page is loaded and written again in
+    ** this transaction, it may be written to the database file before
+    ** it is synced into the journal file. This way, it may end up in
+    ** the journal file twice, but that is not a problem.
+    **
+    ** The sqlite3PagerGet() call may cause the journal to sync. So make
+    ** sure the Pager.needSync flag is set too.
+    */
+    int rc;
+    PgHdr *pPgHdr;
+    assert( pPager->needSync );
+    rc = sqlite3PagerGet(pPager, needSyncPgno, &pPgHdr);
+    if( rc!=SQLITE_OK ){
+      if( pPager->pInJournal && (int)needSyncPgno<=pPager->origDbSize ){
+        sqlite3BitvecClear(pPager->pInJournal, needSyncPgno);
+      }
+      pagerLeave(pPager);
+      return rc;
+    }
+    pPager->needSync = 1;
+    pPgHdr->needSync = 1;
+    pPgHdr->inJournal = 1;
+    makeDirty(pPgHdr);
+    sqlite3PagerUnref(pPgHdr);
+  }
+
+  pagerLeave(pPager);
+  return SQLITE_OK;
+}
+#endif
+
+/* Begin preload-cache.patch for Chromium */
+/**
+** When making large allocations, there is no need to stress the heap and
+** potentially hold its lock while we allocate a bunch of memory.  If we know
+** the allocation will be large, go directly to the OS instead of the heap.
+**/
+static void* allocLarge(size_t size) {
+#if SQLITE_OS_WIN
+  return VirtualAlloc(NULL, size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
+#else
+  return sqlite3Malloc(size);
+#endif
+}
+
+static void freeLarge(void* ptr) {
+#if SQLITE_OS_WIN
+  VirtualFree(ptr, 0, MEM_RELEASE);
+#else
+  sqlite3_free(ptr);
+#endif
+}
+
+/**
+** Addition: This will attempt to populate the database cache with
+** the first N bytes of the file, where N is the total size of the cache.
+** Because we can load this as one chunk from the disk, this is much faster
+** than loading a subset of the pages one at a time in random order.
+**
+** The pager must be initialized before this function is called. This means a
+* statement must be open that has initialized the pager and is keeping the
+** cache in memory.
+**/
+int sqlite3PagerLoadall(Pager* pPager)
+{
+  int i;
+  int rc;
+  int loadSize;
+  int loadPages;
+  unsigned char *fileData;
+
+  if (pPager->dbSize < 0 || pPager->pageSize < 0) {
+    /* pager not initialized, this means a statement is not open */
+    return SQLITE_MISUSE;
+  }
+
+  /* compute sizes */
+  if (pPager->mxPage < pPager->dbSize)
+    loadPages = pPager->mxPage;
+  else
+    loadPages = pPager->dbSize;
+  loadSize = loadPages * pPager->pageSize;
+
+  /* load the file as one chunk */
+  fileData = allocLarge(loadSize);
+  if (! fileData)
+    return SQLITE_NOMEM;
+  rc = sqlite3OsRead(pPager->fd, fileData, loadSize, 0);
+  if (rc != SQLITE_OK) {
+    freeLarge(fileData);
+    return rc;
+  }
+
+  /* Copy the data to each page. Note that the page numbers we pass to _get
+   * are one-based, 0 is a marker for no page. We also need to check that we
+   * haven't loaded more pages than the cache can hold total. There may have
+   * already been a few pages loaded before, so we may fill the cache before
+   * loading all of the pages we want to.
+   */
+  for(i=1; i <= loadPages && pPager->nPage < pPager->mxPage; i++) {
+    DbPage *pPage;
+    rc = sqlite3PagerAcquire2(pPager, i, &pPage, 0,
+                              &fileData[(i-1)*(i64)pPager->pageSize]);
+    if (rc != SQLITE_OK)
+      break;
+    sqlite3PagerUnref(pPage);
+  }
+  freeLarge(fileData);
+  return SQLITE_OK;
+}
+/* End preload-cache.patch for Chromium */
+
+/*
+** Return a pointer to the data for the specified page.
+*/
+void *sqlite3PagerGetData(DbPage *pPg){
+  return PGHDR_TO_DATA(pPg);
+}
+
+/*
+** Return a pointer to the Pager.nExtra bytes of "extra" space 
+** allocated along with the specified page.
+*/
+void *sqlite3PagerGetExtra(DbPage *pPg){
+  Pager *pPager = pPg->pPager;
+  return (pPager?PGHDR_TO_EXTRA(pPg, pPager):0);
+}
+
+/*
+** Get/set the locking-mode for this pager. Parameter eMode must be one
+** of PAGER_LOCKINGMODE_QUERY, PAGER_LOCKINGMODE_NORMAL or 
+** PAGER_LOCKINGMODE_EXCLUSIVE. If the parameter is not _QUERY, then
+** the locking-mode is set to the value specified.
+**
+** The returned value is either PAGER_LOCKINGMODE_NORMAL or
+** PAGER_LOCKINGMODE_EXCLUSIVE, indicating the current (possibly updated)
+** locking-mode.
+*/
+int sqlite3PagerLockingMode(Pager *pPager, int eMode){
+  assert( eMode==PAGER_LOCKINGMODE_QUERY
+            || eMode==PAGER_LOCKINGMODE_NORMAL
+            || eMode==PAGER_LOCKINGMODE_EXCLUSIVE );
+  assert( PAGER_LOCKINGMODE_QUERY<0 );
+  assert( PAGER_LOCKINGMODE_NORMAL>=0 && PAGER_LOCKINGMODE_EXCLUSIVE>=0 );
+  if( eMode>=0 && !pPager->tempFile ){
+    pPager->exclusiveMode = eMode;
+  }
+  return (int)pPager->exclusiveMode;
+}
+
+/*
+** Get/set the journal-mode for this pager. Parameter eMode must be one
+** of PAGER_JOURNALMODE_QUERY, PAGER_JOURNALMODE_DELETE or 
+** PAGER_JOURNALMODE_PERSIST. If the parameter is not _QUERY, then
+** the journal-mode is set to the value specified.
+**
+** The returned value is either PAGER_JOURNALMODE_DELETE or
+** PAGER_JOURNALMODE_PERSIST, indicating the current (possibly updated)
+** journal-mode.
+*/
+int sqlite3PagerJournalMode(Pager *pPager, int eMode){
+  assert( eMode==PAGER_JOURNALMODE_QUERY
+            || eMode==PAGER_JOURNALMODE_DELETE
+            || eMode==PAGER_JOURNALMODE_PERSIST
+            || eMode==PAGER_JOURNALMODE_OFF );
+  assert( PAGER_JOURNALMODE_QUERY<0 );
+  assert( PAGER_JOURNALMODE_DELETE>=0 && PAGER_JOURNALMODE_PERSIST>=0 );
+  if( eMode>=0 ){
+    pPager->journalMode = eMode;
+  }
+  return (int)pPager->journalMode;
+}
+
+/*
+** Get/set the size-limit used for persistent journal files.
+*/
+i64 sqlite3PagerJournalSizeLimit(Pager *pPager, i64 iLimit){
+  if( iLimit>=-1 ){
+    pPager->journalSizeLimit = iLimit;
+  }
+  return pPager->journalSizeLimit;
+}
+
+#endif /* SQLITE_OMIT_DISKIO */
diff --git a/third_party/sqlite/src/pager.h b/third_party/sqlite/src/pager.h
new file mode 100755
index 0000000..9c989c3
--- /dev/null
+++ b/third_party/sqlite/src/pager.h
@@ -0,0 +1,146 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This header file defines the interface that the sqlite page cache
+** subsystem.  The page cache subsystem reads and writes a file a page
+** at a time and provides a journal for rollback.
+**
+** @(#) $Id: pager.h,v 1.77 2008/07/16 18:17:56 danielk1977 Exp $
+*/
+
+#ifndef _PAGER_H_
+#define _PAGER_H_
+
+/*
+** If defined as non-zero, auto-vacuum is enabled by default. Otherwise
+** it must be turned on for each database using "PRAGMA auto_vacuum = 1".
+*/
+#ifndef SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT
+  #define SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT -1
+#endif
+
+/*
+** The type used to represent a page number.  The first page in a file
+** is called page 1.  0 is used to represent "not a page".
+*/
+typedef u32 Pgno;
+
+/*
+** Each open file is managed by a separate instance of the "Pager" structure.
+*/
+typedef struct Pager Pager;
+
+/*
+** Handle type for pages.
+*/
+typedef struct PgHdr DbPage;
+
+/*
+** Allowed values for the flags parameter to sqlite3PagerOpen().
+**
+** NOTE: This values must match the corresponding BTREE_ values in btree.h.
+*/
+#define PAGER_OMIT_JOURNAL  0x0001    /* Do not use a rollback journal */
+#define PAGER_NO_READLOCK   0x0002    /* Omit readlocks on readonly files */
+
+/*
+** Valid values for the second argument to sqlite3PagerLockingMode().
+*/
+#define PAGER_LOCKINGMODE_QUERY      -1
+#define PAGER_LOCKINGMODE_NORMAL      0
+#define PAGER_LOCKINGMODE_EXCLUSIVE   1
+
+/*
+** Valid values for the second argument to sqlite3PagerJournalMode().
+*/
+#define PAGER_JOURNALMODE_QUERY      -1
+#define PAGER_JOURNALMODE_DELETE      0   /* Commit by deleting journal file */
+#define PAGER_JOURNALMODE_PERSIST     1   /* Commit by zeroing journal header */
+#define PAGER_JOURNALMODE_OFF         2   /* Journal omitted.  */
+
+/*
+** See source code comments for a detailed description of the following
+** routines:
+*/
+int sqlite3PagerOpen(sqlite3_vfs *, Pager **ppPager, const char*, int,int,int);
+void sqlite3PagerSetBusyhandler(Pager*, BusyHandler *pBusyHandler);
+void sqlite3PagerSetDestructor(Pager*, void(*)(DbPage*,int));
+void sqlite3PagerSetReiniter(Pager*, void(*)(DbPage*,int));
+int sqlite3PagerSetPagesize(Pager*, u16*);
+int sqlite3PagerMaxPageCount(Pager*, int);
+int sqlite3PagerReadFileheader(Pager*, int, unsigned char*);
+void sqlite3PagerSetCachesize(Pager*, int);
+int sqlite3PagerClose(Pager *pPager);
+int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
+#define sqlite3PagerGet(A,B,C) sqlite3PagerAcquire(A,B,C,0)
+DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);
+int sqlite3PagerRef(DbPage*);
+int sqlite3PagerUnref(DbPage*);
+int sqlite3PagerWrite(DbPage*);
+int sqlite3PagerPagecount(Pager*, int*);
+int sqlite3PagerTruncate(Pager*,Pgno);
+int sqlite3PagerBegin(DbPage*, int exFlag);
+int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, Pgno, int);
+int sqlite3PagerCommitPhaseTwo(Pager*);
+int sqlite3PagerRollback(Pager*);
+int sqlite3PagerIsreadonly(Pager*);
+int sqlite3PagerStmtBegin(Pager*);
+int sqlite3PagerStmtCommit(Pager*);
+int sqlite3PagerStmtRollback(Pager*);
+void sqlite3PagerDontRollback(DbPage*);
+void sqlite3PagerDontWrite(DbPage*);
+int sqlite3PagerRefcount(Pager*);
+void sqlite3PagerSetSafetyLevel(Pager*,int,int);
+const char *sqlite3PagerFilename(Pager*);
+const sqlite3_vfs *sqlite3PagerVfs(Pager*);
+sqlite3_file *sqlite3PagerFile(Pager*);
+const char *sqlite3PagerDirname(Pager*);
+const char *sqlite3PagerJournalname(Pager*);
+int sqlite3PagerNosync(Pager*);
+int sqlite3PagerMovepage(Pager*,DbPage*,Pgno,int);
+void *sqlite3PagerGetData(DbPage *); 
+void *sqlite3PagerGetExtra(DbPage *); 
+int sqlite3PagerLockingMode(Pager *, int);
+/* This function is for preload-cache.patch for Chromium: */
+int sqlite3PagerLoadall(Pager*);
+int sqlite3PagerJournalMode(Pager *, int);
+i64 sqlite3PagerJournalSizeLimit(Pager *, i64);
+void *sqlite3PagerTempSpace(Pager*);
+int sqlite3PagerSync(Pager *pPager);
+
+#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) && !defined(SQLITE_OMIT_DISKIO)
+  int sqlite3PagerReleaseMemory(int);
+#endif
+
+#ifdef SQLITE_HAS_CODEC
+  void sqlite3PagerSetCodec(Pager*,void*(*)(void*,void*,Pgno,int),void*);
+#endif
+
+#if !defined(NDEBUG) || defined(SQLITE_TEST)
+  Pgno sqlite3PagerPagenumber(DbPage*);
+  int sqlite3PagerIswriteable(DbPage*);
+#endif
+
+#ifdef SQLITE_TEST
+  int *sqlite3PagerStats(Pager*);
+  void sqlite3PagerRefdump(Pager*);
+  int sqlite3PagerIsMemdb(Pager*);
+#endif
+
+#ifdef SQLITE_TEST
+void disable_simulated_io_errors(void);
+void enable_simulated_io_errors(void);
+#else
+# define disable_simulated_io_errors()
+# define enable_simulated_io_errors()
+#endif
+
+#endif /* _PAGER_H_ */
diff --git a/third_party/sqlite/src/parse.y b/third_party/sqlite/src/parse.y
new file mode 100755
index 0000000..3ff8d65
--- /dev/null
+++ b/third_party/sqlite/src/parse.y
@@ -0,0 +1,1122 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains SQLite's grammar for SQL.  Process this file
+** using the lemon parser generator to generate C code that runs
+** the parser.  Lemon will also generate a header file containing
+** numeric codes for all of the tokens.
+**
+** @(#) $Id: parse.y,v 1.248 2008/07/31 01:40:42 shane Exp $
+*/
+
+// All token codes are small integers with #defines that begin with "TK_"
+%token_prefix TK_
+
+// The type of the data attached to each token is Token.  This is also the
+// default type for non-terminals.
+//
+%token_type {Token}
+%default_type {Token}
+
+// The generated parser function takes a 4th argument as follows:
+%extra_argument {Parse *pParse}
+
+// This code runs whenever there is a syntax error
+//
+%syntax_error {
+  assert( TOKEN.z[0] );  /* The tokenizer always gives us a token */
+  sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &TOKEN);
+  pParse->parseError = 1;
+}
+%stack_overflow {
+  sqlite3ErrorMsg(pParse, "parser stack overflow");
+  pParse->parseError = 1;
+}
+
+// The name of the generated procedure that implements the parser
+// is as follows:
+%name sqlite3Parser
+
+// The following text is included near the beginning of the C source
+// code file that implements the parser.
+//
+%include {
+#include "sqliteInt.h"
+
+/*
+** An instance of this structure holds information about the
+** LIMIT clause of a SELECT statement.
+*/
+struct LimitVal {
+  Expr *pLimit;    /* The LIMIT expression.  NULL if there is no limit */
+  Expr *pOffset;   /* The OFFSET expression.  NULL if there is none */
+};
+
+/*
+** An instance of this structure is used to store the LIKE,
+** GLOB, NOT LIKE, and NOT GLOB operators.
+*/
+struct LikeOp {
+  Token eOperator;  /* "like" or "glob" or "regexp" */
+  int not;         /* True if the NOT keyword is present */
+};
+
+/*
+** An instance of the following structure describes the event of a
+** TRIGGER.  "a" is the event type, one of TK_UPDATE, TK_INSERT,
+** TK_DELETE, or TK_INSTEAD.  If the event is of the form
+**
+**      UPDATE ON (a,b,c)
+**
+** Then the "b" IdList records the list "a,b,c".
+*/
+struct TrigEvent { int a; IdList * b; };
+
+/*
+** An instance of this structure holds the ATTACH key and the key type.
+*/
+struct AttachKey { int type;  Token key; };
+
+} // end %include
+
+// Input is a single SQL command
+input ::= cmdlist.
+cmdlist ::= cmdlist ecmd.
+cmdlist ::= ecmd.
+cmdx ::= cmd.           { sqlite3FinishCoding(pParse); }
+ecmd ::= SEMI.
+ecmd ::= explain cmdx SEMI.
+explain ::= .           { sqlite3BeginParse(pParse, 0); }
+%ifndef SQLITE_OMIT_EXPLAIN
+explain ::= EXPLAIN.              { sqlite3BeginParse(pParse, 1); }
+explain ::= EXPLAIN QUERY PLAN.   { sqlite3BeginParse(pParse, 2); }
+%endif  SQLITE_OMIT_EXPLAIN
+
+///////////////////// Begin and end transactions. ////////////////////////////
+//
+
+cmd ::= BEGIN transtype(Y) trans_opt.  {sqlite3BeginTransaction(pParse, Y);}
+trans_opt ::= .
+trans_opt ::= TRANSACTION.
+trans_opt ::= TRANSACTION nm.
+%type transtype {int}
+%ifdef SQLITE_TRANSACTION_DEFAULT_IMMEDIATE
+transtype(A) ::= .             {A = TK_IMMEDIATE;}
+%endif  SQLITE_TRANSACTION_DEFAULT_IMMEDIATE
+%ifndef SQLITE_TRANSACTION_DEFAULT_IMMEDIATE
+transtype(A) ::= .             {A = TK_DEFERRED;}
+%endif  SQLITE_TRANSACTION_DEFAULT_IMMEDIATE
+transtype(A) ::= DEFERRED(X).  {A = @X;}
+transtype(A) ::= IMMEDIATE(X). {A = @X;}
+transtype(A) ::= EXCLUSIVE(X). {A = @X;}
+cmd ::= COMMIT trans_opt.      {sqlite3CommitTransaction(pParse);}
+cmd ::= END trans_opt.         {sqlite3CommitTransaction(pParse);}
+cmd ::= ROLLBACK trans_opt.    {sqlite3RollbackTransaction(pParse);}
+
+///////////////////// The CREATE TABLE statement ////////////////////////////
+//
+cmd ::= create_table create_table_args.
+create_table ::= CREATE temp(T) TABLE ifnotexists(E) nm(Y) dbnm(Z). {
+   sqlite3StartTable(pParse,&Y,&Z,T,0,0,E);
+}
+%type ifnotexists {int}
+ifnotexists(A) ::= .              {A = 0;}
+ifnotexists(A) ::= IF NOT EXISTS. {A = 1;}
+%type temp {int}
+%ifndef SQLITE_OMIT_TEMPDB
+temp(A) ::= TEMP.  {A = 1;}
+%endif  SQLITE_OMIT_TEMPDB
+temp(A) ::= .      {A = 0;}
+create_table_args ::= LP columnlist conslist_opt(X) RP(Y). {
+  sqlite3EndTable(pParse,&X,&Y,0);
+}
+create_table_args ::= AS select(S). {
+  sqlite3EndTable(pParse,0,0,S);
+  sqlite3SelectDelete(pParse->db, S);
+}
+columnlist ::= columnlist COMMA column.
+columnlist ::= column.
+
+// A "column" is a complete description of a single column in a
+// CREATE TABLE statement.  This includes the column name, its
+// datatype, and other keywords such as PRIMARY KEY, UNIQUE, REFERENCES,
+// NOT NULL and so forth.
+//
+column(A) ::= columnid(X) type carglist. {
+  A.z = X.z;
+  A.n = (pParse->sLastToken.z-X.z) + pParse->sLastToken.n;
+}
+columnid(A) ::= nm(X). {
+  sqlite3AddColumn(pParse,&X);
+  A = X;
+}
+
+
+// An IDENTIFIER can be a generic identifier, or one of several
+// keywords.  Any non-standard keyword can also be an identifier.
+//
+%type id {Token}
+id(A) ::= ID(X).         {A = X;}
+
+// The following directive causes tokens ABORT, AFTER, ASC, etc. to
+// fallback to ID if they will not parse as their original value.
+// This obviates the need for the "id" nonterminal.
+//
+%fallback ID
+  ABORT AFTER ANALYZE ASC ATTACH BEFORE BEGIN CASCADE CAST CONFLICT
+  DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL FOR
+  IGNORE IMMEDIATE INITIALLY INSTEAD LIKE_KW MATCH PLAN
+  QUERY KEY OF OFFSET PRAGMA RAISE REPLACE RESTRICT ROW
+  TEMP TRIGGER VACUUM VIEW VIRTUAL
+%ifdef SQLITE_OMIT_COMPOUND_SELECT
+  EXCEPT INTERSECT UNION
+%endif SQLITE_OMIT_COMPOUND_SELECT
+  REINDEX RENAME CTIME_KW IF
+  .
+%wildcard ANY.
+
+// Define operator precedence early so that this is the first occurance
+// of the operator tokens in the grammer.  Keeping the operators together
+// causes them to be assigned integer values that are close together,
+// which keeps parser tables smaller.
+//
+// The token values assigned to these symbols is determined by the order
+// in which lemon first sees them.  It must be the case that ISNULL/NOTNULL,
+// NE/EQ, GT/LE, and GE/LT are separated by only a single value.  See
+// the sqlite3ExprIfFalse() routine for additional information on this
+// constraint.
+//
+%left OR.
+%left AND.
+%right NOT.
+%left IS MATCH LIKE_KW BETWEEN IN ISNULL NOTNULL NE EQ.
+%left GT LE LT GE.
+%right ESCAPE.
+%left BITAND BITOR LSHIFT RSHIFT.
+%left PLUS MINUS.
+%left STAR SLASH REM.
+%left CONCAT.
+%left COLLATE.
+%right UMINUS UPLUS BITNOT.
+
+// And "ids" is an identifer-or-string.
+//
+%type ids {Token}
+ids(A) ::= ID|STRING(X).   {A = X;}
+
+// The name of a column or table can be any of the following:
+//
+%type nm {Token}
+nm(A) ::= ID(X).         {A = X;}
+nm(A) ::= STRING(X).     {A = X;}
+nm(A) ::= JOIN_KW(X).    {A = X;}
+
+// A typetoken is really one or more tokens that form a type name such
+// as can be found after the column name in a CREATE TABLE statement.
+// Multiple tokens are concatenated to form the value of the typetoken.
+//
+%type typetoken {Token}
+type ::= .
+type ::= typetoken(X).                   {sqlite3AddColumnType(pParse,&X);}
+typetoken(A) ::= typename(X).   {A = X;}
+typetoken(A) ::= typename(X) LP signed RP(Y). {
+  A.z = X.z;
+  A.n = &Y.z[Y.n] - X.z;
+}
+typetoken(A) ::= typename(X) LP signed COMMA signed RP(Y). {
+  A.z = X.z;
+  A.n = &Y.z[Y.n] - X.z;
+}
+%type typename {Token}
+typename(A) ::= ids(X).             {A = X;}
+typename(A) ::= typename(X) ids(Y). {A.z=X.z; A.n=Y.n+(Y.z-X.z);}
+signed ::= plus_num.
+signed ::= minus_num.
+
+// "carglist" is a list of additional constraints that come after the
+// column name and column type in a CREATE TABLE statement.
+//
+carglist ::= carglist carg.
+carglist ::= .
+carg ::= CONSTRAINT nm ccons.
+carg ::= ccons.
+ccons ::= DEFAULT term(X).            {sqlite3AddDefaultValue(pParse,X);}
+ccons ::= DEFAULT LP expr(X) RP.      {sqlite3AddDefaultValue(pParse,X);}
+ccons ::= DEFAULT PLUS term(X).       {sqlite3AddDefaultValue(pParse,X);}
+ccons ::= DEFAULT MINUS term(X).      {
+  Expr *p = sqlite3PExpr(pParse, TK_UMINUS, X, 0, 0);
+  sqlite3AddDefaultValue(pParse,p);
+}
+ccons ::= DEFAULT id(X).              {
+  Expr *p = sqlite3PExpr(pParse, TK_STRING, 0, 0, &X);
+  sqlite3AddDefaultValue(pParse,p);
+}
+
+// In addition to the type name, we also care about the primary key and
+// UNIQUE constraints.
+//
+ccons ::= NULL onconf.
+ccons ::= NOT NULL onconf(R).               {sqlite3AddNotNull(pParse, R);}
+ccons ::= PRIMARY KEY sortorder(Z) onconf(R) autoinc(I).
+                                     {sqlite3AddPrimaryKey(pParse,0,R,I,Z);}
+ccons ::= UNIQUE onconf(R).    {sqlite3CreateIndex(pParse,0,0,0,0,R,0,0,0,0);}
+ccons ::= CHECK LP expr(X) RP.       {sqlite3AddCheckConstraint(pParse,X);}
+ccons ::= REFERENCES nm(T) idxlist_opt(TA) refargs(R).
+                                {sqlite3CreateForeignKey(pParse,0,&T,TA,R);}
+ccons ::= defer_subclause(D).   {sqlite3DeferForeignKey(pParse,D);}
+ccons ::= COLLATE ids(C).  {sqlite3AddCollateType(pParse, &C);}
+
+// The optional AUTOINCREMENT keyword
+%type autoinc {int}
+autoinc(X) ::= .          {X = 0;}
+autoinc(X) ::= AUTOINCR.  {X = 1;}
+
+// The next group of rules parses the arguments to a REFERENCES clause
+// that determine if the referential integrity checking is deferred or
+// or immediate and which determine what action to take if a ref-integ
+// check fails.
+//
+%type refargs {int}
+refargs(A) ::= .                     { A = OE_Restrict * 0x010101; }
+refargs(A) ::= refargs(X) refarg(Y). { A = (X & Y.mask) | Y.value; }
+%type refarg {struct {int value; int mask;}}
+refarg(A) ::= MATCH nm.              { A.value = 0;     A.mask = 0x000000; }
+refarg(A) ::= ON DELETE refact(X).   { A.value = X;     A.mask = 0x0000ff; }
+refarg(A) ::= ON UPDATE refact(X).   { A.value = X<<8;  A.mask = 0x00ff00; }
+refarg(A) ::= ON INSERT refact(X).   { A.value = X<<16; A.mask = 0xff0000; }
+%type refact {int}
+refact(A) ::= SET NULL.              { A = OE_SetNull; }
+refact(A) ::= SET DEFAULT.           { A = OE_SetDflt; }
+refact(A) ::= CASCADE.               { A = OE_Cascade; }
+refact(A) ::= RESTRICT.              { A = OE_Restrict; }
+%type defer_subclause {int}
+defer_subclause(A) ::= NOT DEFERRABLE init_deferred_pred_opt(X).  {A = X;}
+defer_subclause(A) ::= DEFERRABLE init_deferred_pred_opt(X).      {A = X;}
+%type init_deferred_pred_opt {int}
+init_deferred_pred_opt(A) ::= .                       {A = 0;}
+init_deferred_pred_opt(A) ::= INITIALLY DEFERRED.     {A = 1;}
+init_deferred_pred_opt(A) ::= INITIALLY IMMEDIATE.    {A = 0;}
+
+// For the time being, the only constraint we care about is the primary
+// key and UNIQUE.  Both create indices.
+//
+conslist_opt(A) ::= .                   {A.n = 0; A.z = 0;}
+conslist_opt(A) ::= COMMA(X) conslist.  {A = X;}
+conslist ::= conslist COMMA tcons.
+conslist ::= conslist tcons.
+conslist ::= tcons.
+tcons ::= CONSTRAINT nm.
+tcons ::= PRIMARY KEY LP idxlist(X) autoinc(I) RP onconf(R).
+                                         {sqlite3AddPrimaryKey(pParse,X,R,I,0);}
+tcons ::= UNIQUE LP idxlist(X) RP onconf(R).
+                                 {sqlite3CreateIndex(pParse,0,0,0,X,R,0,0,0,0);}
+tcons ::= CHECK LP expr(E) RP onconf. {sqlite3AddCheckConstraint(pParse,E);}
+tcons ::= FOREIGN KEY LP idxlist(FA) RP
+          REFERENCES nm(T) idxlist_opt(TA) refargs(R) defer_subclause_opt(D). {
+    sqlite3CreateForeignKey(pParse, FA, &T, TA, R);
+    sqlite3DeferForeignKey(pParse, D);
+}
+%type defer_subclause_opt {int}
+defer_subclause_opt(A) ::= .                    {A = 0;}
+defer_subclause_opt(A) ::= defer_subclause(X).  {A = X;}
+
+// The following is a non-standard extension that allows us to declare the
+// default behavior when there is a constraint conflict.
+//
+%type onconf {int}
+%type orconf {int}
+%type resolvetype {int}
+onconf(A) ::= .                              {A = OE_Default;}
+onconf(A) ::= ON CONFLICT resolvetype(X).    {A = X;}
+orconf(A) ::= .                              {A = OE_Default;}
+orconf(A) ::= OR resolvetype(X).             {A = X;}
+resolvetype(A) ::= raisetype(X).             {A = X;}
+resolvetype(A) ::= IGNORE.                   {A = OE_Ignore;}
+resolvetype(A) ::= REPLACE.                  {A = OE_Replace;}
+
+////////////////////////// The DROP TABLE /////////////////////////////////////
+//
+cmd ::= DROP TABLE ifexists(E) fullname(X). {
+  sqlite3DropTable(pParse, X, 0, E);
+}
+%type ifexists {int}
+ifexists(A) ::= IF EXISTS.   {A = 1;}
+ifexists(A) ::= .            {A = 0;}
+
+///////////////////// The CREATE VIEW statement /////////////////////////////
+//
+%ifndef SQLITE_OMIT_VIEW
+cmd ::= CREATE(X) temp(T) VIEW ifnotexists(E) nm(Y) dbnm(Z) AS select(S). {
+  sqlite3CreateView(pParse, &X, &Y, &Z, S, T, E);
+}
+cmd ::= DROP VIEW ifexists(E) fullname(X). {
+  sqlite3DropTable(pParse, X, 1, E);
+}
+%endif  SQLITE_OMIT_VIEW
+
+//////////////////////// The SELECT statement /////////////////////////////////
+//
+cmd ::= select(X).  {
+  SelectDest dest = {SRT_Callback, 0, 0, 0, 0};
+  sqlite3Select(pParse, X, &dest, 0, 0, 0);
+  sqlite3SelectDelete(pParse->db, X);
+}
+
+%type select {Select*}
+%destructor select {sqlite3SelectDelete(pParse->db, $$);}
+%type oneselect {Select*}
+%destructor oneselect {sqlite3SelectDelete(pParse->db, $$);}
+
+select(A) ::= oneselect(X).                      {A = X;}
+%ifndef SQLITE_OMIT_COMPOUND_SELECT
+select(A) ::= select(X) multiselect_op(Y) oneselect(Z).  {
+  if( Z ){
+    Z->op = Y;
+    Z->pPrior = X;
+  }else{
+    sqlite3SelectDelete(pParse->db, X);
+  }
+  A = Z;
+}
+%type multiselect_op {int}
+multiselect_op(A) ::= UNION(OP).             {A = @OP;}
+multiselect_op(A) ::= UNION ALL.             {A = TK_ALL;}
+multiselect_op(A) ::= EXCEPT|INTERSECT(OP).  {A = @OP;}
+%endif SQLITE_OMIT_COMPOUND_SELECT
+oneselect(A) ::= SELECT distinct(D) selcollist(W) from(X) where_opt(Y)
+                 groupby_opt(P) having_opt(Q) orderby_opt(Z) limit_opt(L). {
+  A = sqlite3SelectNew(pParse,W,X,Y,P,Q,Z,D,L.pLimit,L.pOffset);
+}
+
+// The "distinct" nonterminal is true (1) if the DISTINCT keyword is
+// present and false (0) if it is not.
+//
+%type distinct {int}
+distinct(A) ::= DISTINCT.   {A = 1;}
+distinct(A) ::= ALL.        {A = 0;}
+distinct(A) ::= .           {A = 0;}
+
+// selcollist is a list of expressions that are to become the return
+// values of the SELECT statement.  The "*" in statements like
+// "SELECT * FROM ..." is encoded as a special expression with an
+// opcode of TK_ALL.
+//
+%type selcollist {ExprList*}
+%destructor selcollist {sqlite3ExprListDelete(pParse->db, $$);}
+%type sclp {ExprList*}
+%destructor sclp {sqlite3ExprListDelete(pParse->db, $$);}
+sclp(A) ::= selcollist(X) COMMA.             {A = X;}
+sclp(A) ::= .                                {A = 0;}
+selcollist(A) ::= sclp(P) expr(X) as(Y).     {
+   A = sqlite3ExprListAppend(pParse,P,X,Y.n?&Y:0);
+}
+selcollist(A) ::= sclp(P) STAR. {
+  Expr *p = sqlite3PExpr(pParse, TK_ALL, 0, 0, 0);
+  A = sqlite3ExprListAppend(pParse, P, p, 0);
+}
+selcollist(A) ::= sclp(P) nm(X) DOT STAR(Y). {
+  Expr *pRight = sqlite3PExpr(pParse, TK_ALL, 0, 0, &Y);
+  Expr *pLeft = sqlite3PExpr(pParse, TK_ID, 0, 0, &X);
+  Expr *pDot = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
+  A = sqlite3ExprListAppend(pParse,P, pDot, 0);
+}
+
+// An option "AS <id>" phrase that can follow one of the expressions that
+// define the result set, or one of the tables in the FROM clause.
+//
+%type as {Token}
+as(X) ::= AS nm(Y).    {X = Y;}
+as(X) ::= ids(Y).      {X = Y;}
+as(X) ::= .            {X.n = 0;}
+
+
+%type seltablist {SrcList*}
+%destructor seltablist {sqlite3SrcListDelete(pParse->db, $$);}
+%type stl_prefix {SrcList*}
+%destructor stl_prefix {sqlite3SrcListDelete(pParse->db, $$);}
+%type from {SrcList*}
+%destructor from {sqlite3SrcListDelete(pParse->db, $$);}
+
+// A complete FROM clause.
+//
+from(A) ::= .                {A = sqlite3DbMallocZero(pParse->db, sizeof(*A));}
+from(A) ::= FROM seltablist(X).  {
+  A = X;
+  sqlite3SrcListShiftJoinType(A);
+}
+
+// "seltablist" is a "Select Table List" - the content of the FROM clause
+// in a SELECT statement.  "stl_prefix" is a prefix of this list.
+//
+stl_prefix(A) ::= seltablist(X) joinop(Y).    {
+   A = X;
+   if( A && A->nSrc>0 ) A->a[A->nSrc-1].jointype = Y;
+}
+stl_prefix(A) ::= .                           {A = 0;}
+seltablist(A) ::= stl_prefix(X) nm(Y) dbnm(D) as(Z) on_opt(N) using_opt(U). {
+  A = sqlite3SrcListAppendFromTerm(pParse,X,&Y,&D,&Z,0,N,U);
+}
+%ifndef SQLITE_OMIT_SUBQUERY
+  seltablist(A) ::= stl_prefix(X) LP seltablist_paren(S) RP
+                    as(Z) on_opt(N) using_opt(U). {
+    A = sqlite3SrcListAppendFromTerm(pParse,X,0,0,&Z,S,N,U);
+  }
+  
+  // A seltablist_paren nonterminal represents anything in a FROM that
+  // is contained inside parentheses.  This can be either a subquery or
+  // a grouping of table and subqueries.
+  //
+  %type seltablist_paren {Select*}
+  %destructor seltablist_paren {sqlite3SelectDelete(pParse->db, $$);}
+  seltablist_paren(A) ::= select(S).      {A = S;}
+  seltablist_paren(A) ::= seltablist(F).  {
+     sqlite3SrcListShiftJoinType(F);
+     A = sqlite3SelectNew(pParse,0,F,0,0,0,0,0,0,0);
+  }
+%endif  SQLITE_OMIT_SUBQUERY
+
+%type dbnm {Token}
+dbnm(A) ::= .          {A.z=0; A.n=0;}
+dbnm(A) ::= DOT nm(X). {A = X;}
+
+%type fullname {SrcList*}
+%destructor fullname {sqlite3SrcListDelete(pParse->db, $$);}
+fullname(A) ::= nm(X) dbnm(Y).  {A = sqlite3SrcListAppend(pParse->db,0,&X,&Y);}
+
+%type joinop {int}
+%type joinop2 {int}
+joinop(X) ::= COMMA|JOIN.              { X = JT_INNER; }
+joinop(X) ::= JOIN_KW(A) JOIN.         { X = sqlite3JoinType(pParse,&A,0,0); }
+joinop(X) ::= JOIN_KW(A) nm(B) JOIN.   { X = sqlite3JoinType(pParse,&A,&B,0); }
+joinop(X) ::= JOIN_KW(A) nm(B) nm(C) JOIN.
+                                       { X = sqlite3JoinType(pParse,&A,&B,&C); }
+
+%type on_opt {Expr*}
+%destructor on_opt {sqlite3ExprDelete(pParse->db, $$);}
+on_opt(N) ::= ON expr(E).   {N = E;}
+on_opt(N) ::= .             {N = 0;}
+
+%type using_opt {IdList*}
+%destructor using_opt {sqlite3IdListDelete(pParse->db, $$);}
+using_opt(U) ::= USING LP inscollist(L) RP.  {U = L;}
+using_opt(U) ::= .                        {U = 0;}
+
+
+%type orderby_opt {ExprList*}
+%destructor orderby_opt {sqlite3ExprListDelete(pParse->db, $$);}
+%type sortlist {ExprList*}
+%destructor sortlist {sqlite3ExprListDelete(pParse->db, $$);}
+%type sortitem {Expr*}
+%destructor sortitem {sqlite3ExprDelete(pParse->db, $$);}
+
+orderby_opt(A) ::= .                          {A = 0;}
+orderby_opt(A) ::= ORDER BY sortlist(X).      {A = X;}
+sortlist(A) ::= sortlist(X) COMMA sortitem(Y) sortorder(Z). {
+  A = sqlite3ExprListAppend(pParse,X,Y,0);
+  if( A ) A->a[A->nExpr-1].sortOrder = Z;
+}
+sortlist(A) ::= sortitem(Y) sortorder(Z). {
+  A = sqlite3ExprListAppend(pParse,0,Y,0);
+  if( A && A->a ) A->a[0].sortOrder = Z;
+}
+sortitem(A) ::= expr(X).   {A = X;}
+
+%type sortorder {int}
+
+sortorder(A) ::= ASC.           {A = SQLITE_SO_ASC;}
+sortorder(A) ::= DESC.          {A = SQLITE_SO_DESC;}
+sortorder(A) ::= .              {A = SQLITE_SO_ASC;}
+
+%type groupby_opt {ExprList*}
+%destructor groupby_opt {sqlite3ExprListDelete(pParse->db, $$);}
+groupby_opt(A) ::= .                      {A = 0;}
+groupby_opt(A) ::= GROUP BY nexprlist(X). {A = X;}
+
+%type having_opt {Expr*}
+%destructor having_opt {sqlite3ExprDelete(pParse->db, $$);}
+having_opt(A) ::= .                {A = 0;}
+having_opt(A) ::= HAVING expr(X).  {A = X;}
+
+%type limit_opt {struct LimitVal}
+
+// The destructor for limit_opt will never fire in the current grammar.
+// The limit_opt non-terminal only occurs at the end of a single production
+// rule for SELECT statements.  As soon as the rule that create the 
+// limit_opt non-terminal reduces, the SELECT statement rule will also
+// reduce.  So there is never a limit_opt non-terminal on the stack 
+// except as a transient.  So there is never anything to destroy.
+//
+//%destructor limit_opt {
+//  sqlite3ExprDelete(pParse->db, $$.pLimit);
+//  sqlite3ExprDelete(pParse->db, $$.pOffset);
+//}
+limit_opt(A) ::= .                     {A.pLimit = 0; A.pOffset = 0;}
+limit_opt(A) ::= LIMIT expr(X).        {A.pLimit = X; A.pOffset = 0;}
+limit_opt(A) ::= LIMIT expr(X) OFFSET expr(Y). 
+                                       {A.pLimit = X; A.pOffset = Y;}
+limit_opt(A) ::= LIMIT expr(X) COMMA expr(Y). 
+                                       {A.pOffset = X; A.pLimit = Y;}
+
+/////////////////////////// The DELETE statement /////////////////////////////
+//
+cmd ::= DELETE FROM fullname(X) where_opt(Y). {sqlite3DeleteFrom(pParse,X,Y);}
+
+%type where_opt {Expr*}
+%destructor where_opt {sqlite3ExprDelete(pParse->db, $$);}
+
+where_opt(A) ::= .                    {A = 0;}
+where_opt(A) ::= WHERE expr(X).       {A = X;}
+
+////////////////////////// The UPDATE command ////////////////////////////////
+//
+cmd ::= UPDATE orconf(R) fullname(X) SET setlist(Y) where_opt(Z).  {
+  sqlite3ExprListCheckLength(pParse,Y,"set list"); 
+  sqlite3Update(pParse,X,Y,Z,R);
+}
+
+%type setlist {ExprList*}
+%destructor setlist {sqlite3ExprListDelete(pParse->db, $$);}
+
+setlist(A) ::= setlist(Z) COMMA nm(X) EQ expr(Y).
+    {A = sqlite3ExprListAppend(pParse,Z,Y,&X);}
+setlist(A) ::= nm(X) EQ expr(Y).
+    {A = sqlite3ExprListAppend(pParse,0,Y,&X);}
+
+////////////////////////// The INSERT command /////////////////////////////////
+//
+cmd ::= insert_cmd(R) INTO fullname(X) inscollist_opt(F) 
+        VALUES LP itemlist(Y) RP.
+            {sqlite3Insert(pParse, X, Y, 0, F, R);}
+cmd ::= insert_cmd(R) INTO fullname(X) inscollist_opt(F) select(S).
+            {sqlite3Insert(pParse, X, 0, S, F, R);}
+cmd ::= insert_cmd(R) INTO fullname(X) inscollist_opt(F) DEFAULT VALUES.
+            {sqlite3Insert(pParse, X, 0, 0, F, R);}
+
+%type insert_cmd {int}
+insert_cmd(A) ::= INSERT orconf(R).   {A = R;}
+insert_cmd(A) ::= REPLACE.            {A = OE_Replace;}
+
+
+%type itemlist {ExprList*}
+%destructor itemlist {sqlite3ExprListDelete(pParse->db, $$);}
+
+itemlist(A) ::= itemlist(X) COMMA expr(Y).
+    {A = sqlite3ExprListAppend(pParse,X,Y,0);}
+itemlist(A) ::= expr(X).
+    {A = sqlite3ExprListAppend(pParse,0,X,0);}
+
+%type inscollist_opt {IdList*}
+%destructor inscollist_opt {sqlite3IdListDelete(pParse->db, $$);}
+%type inscollist {IdList*}
+%destructor inscollist {sqlite3IdListDelete(pParse->db, $$);}
+
+inscollist_opt(A) ::= .                       {A = 0;}
+inscollist_opt(A) ::= LP inscollist(X) RP.    {A = X;}
+inscollist(A) ::= inscollist(X) COMMA nm(Y).
+    {A = sqlite3IdListAppend(pParse->db,X,&Y);}
+inscollist(A) ::= nm(Y).
+    {A = sqlite3IdListAppend(pParse->db,0,&Y);}
+
+/////////////////////////// Expression Processing /////////////////////////////
+//
+
+%type expr {Expr*}
+%destructor expr {sqlite3ExprDelete(pParse->db, $$);}
+%type term {Expr*}
+%destructor term {sqlite3ExprDelete(pParse->db, $$);}
+
+expr(A) ::= term(X).             {A = X;}
+expr(A) ::= LP(B) expr(X) RP(E). {A = X; sqlite3ExprSpan(A,&B,&E); }
+term(A) ::= NULL(X).             {A = sqlite3PExpr(pParse, @X, 0, 0, &X);}
+expr(A) ::= ID(X).               {A = sqlite3PExpr(pParse, TK_ID, 0, 0, &X);}
+expr(A) ::= JOIN_KW(X).          {A = sqlite3PExpr(pParse, TK_ID, 0, 0, &X);}
+expr(A) ::= nm(X) DOT nm(Y). {
+  Expr *temp1 = sqlite3PExpr(pParse, TK_ID, 0, 0, &X);
+  Expr *temp2 = sqlite3PExpr(pParse, TK_ID, 0, 0, &Y);
+  A = sqlite3PExpr(pParse, TK_DOT, temp1, temp2, 0);
+}
+expr(A) ::= nm(X) DOT nm(Y) DOT nm(Z). {
+  Expr *temp1 = sqlite3PExpr(pParse, TK_ID, 0, 0, &X);
+  Expr *temp2 = sqlite3PExpr(pParse, TK_ID, 0, 0, &Y);
+  Expr *temp3 = sqlite3PExpr(pParse, TK_ID, 0, 0, &Z);
+  Expr *temp4 = sqlite3PExpr(pParse, TK_DOT, temp2, temp3, 0);
+  A = sqlite3PExpr(pParse, TK_DOT, temp1, temp4, 0);
+}
+term(A) ::= INTEGER|FLOAT|BLOB(X).  {A = sqlite3PExpr(pParse, @X, 0, 0, &X);}
+term(A) ::= STRING(X).       {A = sqlite3PExpr(pParse, @X, 0, 0, &X);}
+expr(A) ::= REGISTER(X).     {A = sqlite3RegisterExpr(pParse, &X);}
+expr(A) ::= VARIABLE(X).     {
+  Token *pToken = &X;
+  Expr *pExpr = A = sqlite3PExpr(pParse, TK_VARIABLE, 0, 0, pToken);
+  sqlite3ExprAssignVarNumber(pParse, pExpr);
+}
+expr(A) ::= expr(E) COLLATE ids(C). {
+  A = sqlite3ExprSetColl(pParse, E, &C);
+}
+%ifndef SQLITE_OMIT_CAST
+expr(A) ::= CAST(X) LP expr(E) AS typetoken(T) RP(Y). {
+  A = sqlite3PExpr(pParse, TK_CAST, E, 0, &T);
+  sqlite3ExprSpan(A,&X,&Y);
+}
+%endif  SQLITE_OMIT_CAST
+expr(A) ::= ID(X) LP distinct(D) exprlist(Y) RP(E). {
+  if( Y && Y->nExpr>SQLITE_MAX_FUNCTION_ARG ){
+    sqlite3ErrorMsg(pParse, "too many arguments on function %T", &X);
+  }
+  A = sqlite3ExprFunction(pParse, Y, &X);
+  sqlite3ExprSpan(A,&X,&E);
+  if( D && A ){
+    A->flags |= EP_Distinct;
+  }
+}
+expr(A) ::= ID(X) LP STAR RP(E). {
+  A = sqlite3ExprFunction(pParse, 0, &X);
+  sqlite3ExprSpan(A,&X,&E);
+}
+term(A) ::= CTIME_KW(OP). {
+  /* The CURRENT_TIME, CURRENT_DATE, and CURRENT_TIMESTAMP values are
+  ** treated as functions that return constants */
+  A = sqlite3ExprFunction(pParse, 0,&OP);
+  if( A ){
+    A->op = TK_CONST_FUNC;  
+    A->span = OP;
+  }
+}
+expr(A) ::= expr(X) AND(OP) expr(Y).       {A = sqlite3PExpr(pParse,@OP,X,Y,0);}
+expr(A) ::= expr(X) OR(OP) expr(Y).        {A = sqlite3PExpr(pParse,@OP,X,Y,0);}
+expr(A) ::= expr(X) LT|GT|GE|LE(OP) expr(Y).
+                                           {A = sqlite3PExpr(pParse,@OP,X,Y,0);}
+expr(A) ::= expr(X) EQ|NE(OP) expr(Y).     {A = sqlite3PExpr(pParse,@OP,X,Y,0);}
+expr(A) ::= expr(X) BITAND|BITOR|LSHIFT|RSHIFT(OP) expr(Y).
+                                           {A = sqlite3PExpr(pParse,@OP,X,Y,0);}
+expr(A) ::= expr(X) PLUS|MINUS(OP) expr(Y).{A = sqlite3PExpr(pParse,@OP,X,Y,0);}
+expr(A) ::= expr(X) STAR|SLASH|REM(OP) expr(Y).
+                                           {A = sqlite3PExpr(pParse,@OP,X,Y,0);}
+expr(A) ::= expr(X) CONCAT(OP) expr(Y).    {A = sqlite3PExpr(pParse,@OP,X,Y,0);}
+%type likeop {struct LikeOp}
+likeop(A) ::= LIKE_KW(X).     {A.eOperator = X; A.not = 0;}
+likeop(A) ::= NOT LIKE_KW(X). {A.eOperator = X; A.not = 1;}
+likeop(A) ::= MATCH(X).       {A.eOperator = X; A.not = 0;}
+likeop(A) ::= NOT MATCH(X).   {A.eOperator = X; A.not = 1;}
+%type escape {Expr*}
+%destructor escape {sqlite3ExprDelete(pParse->db, $$);}
+escape(X) ::= ESCAPE expr(A). [ESCAPE] {X = A;}
+escape(X) ::= .               [ESCAPE] {X = 0;}
+expr(A) ::= expr(X) likeop(OP) expr(Y) escape(E).  [LIKE_KW]  {
+  ExprList *pList;
+  pList = sqlite3ExprListAppend(pParse,0, Y, 0);
+  pList = sqlite3ExprListAppend(pParse,pList, X, 0);
+  if( E ){
+    pList = sqlite3ExprListAppend(pParse,pList, E, 0);
+  }
+  A = sqlite3ExprFunction(pParse, pList, &OP.eOperator);
+  if( OP.not ) A = sqlite3PExpr(pParse, TK_NOT, A, 0, 0);
+  sqlite3ExprSpan(A, &X->span, &Y->span);
+  if( A ) A->flags |= EP_InfixFunc;
+}
+
+expr(A) ::= expr(X) ISNULL|NOTNULL(E). {
+  A = sqlite3PExpr(pParse, @E, X, 0, 0);
+  sqlite3ExprSpan(A,&X->span,&E);
+}
+expr(A) ::= expr(X) IS NULL(E). {
+  A = sqlite3PExpr(pParse, TK_ISNULL, X, 0, 0);
+  sqlite3ExprSpan(A,&X->span,&E);
+}
+expr(A) ::= expr(X) NOT NULL(E). {
+  A = sqlite3PExpr(pParse, TK_NOTNULL, X, 0, 0);
+  sqlite3ExprSpan(A,&X->span,&E);
+}
+expr(A) ::= expr(X) IS NOT NULL(E). {
+  A = sqlite3PExpr(pParse, TK_NOTNULL, X, 0, 0);
+  sqlite3ExprSpan(A,&X->span,&E);
+}
+expr(A) ::= NOT(B) expr(X). {
+  A = sqlite3PExpr(pParse, @B, X, 0, 0);
+  sqlite3ExprSpan(A,&B,&X->span);
+}
+expr(A) ::= BITNOT(B) expr(X). {
+  A = sqlite3PExpr(pParse, @B, X, 0, 0);
+  sqlite3ExprSpan(A,&B,&X->span);
+}
+expr(A) ::= MINUS(B) expr(X). [UMINUS] {
+  A = sqlite3PExpr(pParse, TK_UMINUS, X, 0, 0);
+  sqlite3ExprSpan(A,&B,&X->span);
+}
+expr(A) ::= PLUS(B) expr(X). [UPLUS] {
+  A = sqlite3PExpr(pParse, TK_UPLUS, X, 0, 0);
+  sqlite3ExprSpan(A,&B,&X->span);
+}
+%type between_op {int}
+between_op(A) ::= BETWEEN.     {A = 0;}
+between_op(A) ::= NOT BETWEEN. {A = 1;}
+expr(A) ::= expr(W) between_op(N) expr(X) AND expr(Y). [BETWEEN] {
+  ExprList *pList = sqlite3ExprListAppend(pParse,0, X, 0);
+  pList = sqlite3ExprListAppend(pParse,pList, Y, 0);
+  A = sqlite3PExpr(pParse, TK_BETWEEN, W, 0, 0);
+  if( A ){
+    A->pList = pList;
+  }else{
+    sqlite3ExprListDelete(pParse->db, pList);
+  } 
+  if( N ) A = sqlite3PExpr(pParse, TK_NOT, A, 0, 0);
+  sqlite3ExprSpan(A,&W->span,&Y->span);
+}
+%ifndef SQLITE_OMIT_SUBQUERY
+  %type in_op {int}
+  in_op(A) ::= IN.      {A = 0;}
+  in_op(A) ::= NOT IN.  {A = 1;}
+  expr(A) ::= expr(X) in_op(N) LP exprlist(Y) RP(E). [IN] {
+    A = sqlite3PExpr(pParse, TK_IN, X, 0, 0);
+    if( A ){
+      A->pList = Y;
+      sqlite3ExprSetHeight(pParse, A);
+    }else{
+      sqlite3ExprListDelete(pParse->db, Y);
+    }
+    if( N ) A = sqlite3PExpr(pParse, TK_NOT, A, 0, 0);
+    sqlite3ExprSpan(A,&X->span,&E);
+  }
+  expr(A) ::= LP(B) select(X) RP(E). {
+    A = sqlite3PExpr(pParse, TK_SELECT, 0, 0, 0);
+    if( A ){
+      A->pSelect = X;
+      sqlite3ExprSetHeight(pParse, A);
+    }else{
+      sqlite3SelectDelete(pParse->db, X);
+    }
+    sqlite3ExprSpan(A,&B,&E);
+  }
+  expr(A) ::= expr(X) in_op(N) LP select(Y) RP(E).  [IN] {
+    A = sqlite3PExpr(pParse, TK_IN, X, 0, 0);
+    if( A ){
+      A->pSelect = Y;
+      sqlite3ExprSetHeight(pParse, A);
+    }else{
+      sqlite3SelectDelete(pParse->db, Y);
+    }
+    if( N ) A = sqlite3PExpr(pParse, TK_NOT, A, 0, 0);
+    sqlite3ExprSpan(A,&X->span,&E);
+  }
+  expr(A) ::= expr(X) in_op(N) nm(Y) dbnm(Z). [IN] {
+    SrcList *pSrc = sqlite3SrcListAppend(pParse->db, 0,&Y,&Z);
+    A = sqlite3PExpr(pParse, TK_IN, X, 0, 0);
+    if( A ){
+      A->pSelect = sqlite3SelectNew(pParse, 0,pSrc,0,0,0,0,0,0,0);
+      sqlite3ExprSetHeight(pParse, A);
+    }else{
+      sqlite3SrcListDelete(pParse->db, pSrc);
+    }
+    if( N ) A = sqlite3PExpr(pParse, TK_NOT, A, 0, 0);
+    sqlite3ExprSpan(A,&X->span,Z.z?&Z:&Y);
+  }
+  expr(A) ::= EXISTS(B) LP select(Y) RP(E). {
+    Expr *p = A = sqlite3PExpr(pParse, TK_EXISTS, 0, 0, 0);
+    if( p ){
+      p->pSelect = Y;
+      sqlite3ExprSpan(p,&B,&E);
+      sqlite3ExprSetHeight(pParse, A);
+    }else{
+      sqlite3SelectDelete(pParse->db, Y);
+    }
+  }
+%endif SQLITE_OMIT_SUBQUERY
+
+/* CASE expressions */
+expr(A) ::= CASE(C) case_operand(X) case_exprlist(Y) case_else(Z) END(E). {
+  A = sqlite3PExpr(pParse, TK_CASE, X, Z, 0);
+  if( A ){
+    A->pList = Y;
+    sqlite3ExprSetHeight(pParse, A);
+  }else{
+    sqlite3ExprListDelete(pParse->db, Y);
+  }
+  sqlite3ExprSpan(A, &C, &E);
+}
+%type case_exprlist {ExprList*}
+%destructor case_exprlist {sqlite3ExprListDelete(pParse->db, $$);}
+case_exprlist(A) ::= case_exprlist(X) WHEN expr(Y) THEN expr(Z). {
+  A = sqlite3ExprListAppend(pParse,X, Y, 0);
+  A = sqlite3ExprListAppend(pParse,A, Z, 0);
+}
+case_exprlist(A) ::= WHEN expr(Y) THEN expr(Z). {
+  A = sqlite3ExprListAppend(pParse,0, Y, 0);
+  A = sqlite3ExprListAppend(pParse,A, Z, 0);
+}
+%type case_else {Expr*}
+%destructor case_else {sqlite3ExprDelete(pParse->db, $$);}
+case_else(A) ::=  ELSE expr(X).         {A = X;}
+case_else(A) ::=  .                     {A = 0;} 
+%type case_operand {Expr*}
+%destructor case_operand {sqlite3ExprDelete(pParse->db, $$);}
+case_operand(A) ::= expr(X).            {A = X;} 
+case_operand(A) ::= .                   {A = 0;} 
+
+%type exprlist {ExprList*}
+%destructor exprlist {sqlite3ExprListDelete(pParse->db, $$);}
+%type nexprlist {ExprList*}
+%destructor nexprlist {sqlite3ExprListDelete(pParse->db, $$);}
+
+exprlist(A) ::= nexprlist(X).                {A = X;}
+exprlist(A) ::= .                            {A = 0;}
+nexprlist(A) ::= nexprlist(X) COMMA expr(Y).
+    {A = sqlite3ExprListAppend(pParse,X,Y,0);}
+nexprlist(A) ::= expr(Y).
+    {A = sqlite3ExprListAppend(pParse,0,Y,0);}
+
+
+///////////////////////////// The CREATE INDEX command ///////////////////////
+//
+cmd ::= CREATE(S) uniqueflag(U) INDEX ifnotexists(NE) nm(X) dbnm(D)
+        ON nm(Y) LP idxlist(Z) RP(E). {
+  sqlite3CreateIndex(pParse, &X, &D, 
+                     sqlite3SrcListAppend(pParse->db,0,&Y,0), Z, U,
+                      &S, &E, SQLITE_SO_ASC, NE);
+}
+
+%type uniqueflag {int}
+uniqueflag(A) ::= UNIQUE.  {A = OE_Abort;}
+uniqueflag(A) ::= .        {A = OE_None;}
+
+%type idxlist {ExprList*}
+%destructor idxlist {sqlite3ExprListDelete(pParse->db, $$);}
+%type idxlist_opt {ExprList*}
+%destructor idxlist_opt {sqlite3ExprListDelete(pParse->db, $$);}
+%type idxitem {Token}
+
+idxlist_opt(A) ::= .                         {A = 0;}
+idxlist_opt(A) ::= LP idxlist(X) RP.         {A = X;}
+idxlist(A) ::= idxlist(X) COMMA idxitem(Y) collate(C) sortorder(Z).  {
+  Expr *p = 0;
+  if( C.n>0 ){
+    p = sqlite3PExpr(pParse, TK_COLUMN, 0, 0, 0);
+    sqlite3ExprSetColl(pParse, p, &C);
+  }
+  A = sqlite3ExprListAppend(pParse,X, p, &Y);
+  sqlite3ExprListCheckLength(pParse, A, "index");
+  if( A ) A->a[A->nExpr-1].sortOrder = Z;
+}
+idxlist(A) ::= idxitem(Y) collate(C) sortorder(Z). {
+  Expr *p = 0;
+  if( C.n>0 ){
+    p = sqlite3PExpr(pParse, TK_COLUMN, 0, 0, 0);
+    sqlite3ExprSetColl(pParse, p, &C);
+  }
+  A = sqlite3ExprListAppend(pParse,0, p, &Y);
+  sqlite3ExprListCheckLength(pParse, A, "index");
+  if( A ) A->a[A->nExpr-1].sortOrder = Z;
+}
+idxitem(A) ::= nm(X).              {A = X;}
+
+%type collate {Token}
+collate(C) ::= .                {C.z = 0; C.n = 0;}
+collate(C) ::= COLLATE ids(X).   {C = X;}
+
+
+///////////////////////////// The DROP INDEX command /////////////////////////
+//
+cmd ::= DROP INDEX ifexists(E) fullname(X).   {sqlite3DropIndex(pParse, X, E);}
+
+///////////////////////////// The VACUUM command /////////////////////////////
+//
+%ifndef SQLITE_OMIT_VACUUM
+%ifndef SQLITE_OMIT_ATTACH
+cmd ::= VACUUM.                {sqlite3Vacuum(pParse);}
+cmd ::= VACUUM nm.             {sqlite3Vacuum(pParse);}
+%endif  SQLITE_OMIT_ATTACH
+%endif  SQLITE_OMIT_VACUUM
+
+///////////////////////////// The PRAGMA command /////////////////////////////
+//
+%ifndef SQLITE_OMIT_PARSER
+%ifndef SQLITE_OMIT_PRAGMA
+cmd ::= PRAGMA nm(X) dbnm(Z) EQ nmnum(Y).   {sqlite3Pragma(pParse,&X,&Z,&Y,0);}
+cmd ::= PRAGMA nm(X) dbnm(Z) EQ ON(Y).      {sqlite3Pragma(pParse,&X,&Z,&Y,0);}
+cmd ::= PRAGMA nm(X) dbnm(Z) EQ DELETE(Y).  {sqlite3Pragma(pParse,&X,&Z,&Y,0);}
+cmd ::= PRAGMA nm(X) dbnm(Z) EQ minus_num(Y). {
+  sqlite3Pragma(pParse,&X,&Z,&Y,1);
+}
+cmd ::= PRAGMA nm(X) dbnm(Z) LP nmnum(Y) RP. {sqlite3Pragma(pParse,&X,&Z,&Y,0);}
+cmd ::= PRAGMA nm(X) dbnm(Z).             {sqlite3Pragma(pParse,&X,&Z,0,0);}
+nmnum(A) ::= plus_num(X).             {A = X;}
+nmnum(A) ::= nm(X).                   {A = X;}
+%endif SQLITE_OMIT_PRAGMA
+%endif SQLITE_OMIT_PARSER
+plus_num(A) ::= plus_opt number(X).   {A = X;}
+minus_num(A) ::= MINUS number(X).     {A = X;}
+number(A) ::= INTEGER|FLOAT(X).       {A = X;}
+plus_opt ::= PLUS.
+plus_opt ::= .
+
+//////////////////////////// The CREATE TRIGGER command /////////////////////
+
+%ifndef SQLITE_OMIT_TRIGGER
+
+cmd ::= CREATE trigger_decl(A) BEGIN trigger_cmd_list(S) END(Z). {
+  Token all;
+  all.z = A.z;
+  all.n = (Z.z - A.z) + Z.n;
+  sqlite3FinishTrigger(pParse, S, &all);
+}
+
+trigger_decl(A) ::= temp(T) TRIGGER ifnotexists(NOERR) nm(B) dbnm(Z) 
+                    trigger_time(C) trigger_event(D)
+                    ON fullname(E) foreach_clause when_clause(G). {
+  sqlite3BeginTrigger(pParse, &B, &Z, C, D.a, D.b, E, G, T, NOERR);
+  A = (Z.n==0?B:Z);
+}
+
+%type trigger_time {int}
+trigger_time(A) ::= BEFORE.      { A = TK_BEFORE; }
+trigger_time(A) ::= AFTER.       { A = TK_AFTER;  }
+trigger_time(A) ::= INSTEAD OF.  { A = TK_INSTEAD;}
+trigger_time(A) ::= .            { A = TK_BEFORE; }
+
+%type trigger_event {struct TrigEvent}
+%destructor trigger_event {sqlite3IdListDelete(pParse->db, $$.b);}
+trigger_event(A) ::= DELETE|INSERT(OP).       {A.a = @OP; A.b = 0;}
+trigger_event(A) ::= UPDATE(OP).              {A.a = @OP; A.b = 0;}
+trigger_event(A) ::= UPDATE OF inscollist(X). {A.a = TK_UPDATE; A.b = X;}
+
+foreach_clause ::= .
+foreach_clause ::= FOR EACH ROW.
+
+%type when_clause {Expr*}
+%destructor when_clause {sqlite3ExprDelete(pParse->db, $$);}
+when_clause(A) ::= .             { A = 0; }
+when_clause(A) ::= WHEN expr(X). { A = X; }
+
+%type trigger_cmd_list {TriggerStep*}
+%destructor trigger_cmd_list {sqlite3DeleteTriggerStep(pParse->db, $$);}
+trigger_cmd_list(A) ::= trigger_cmd_list(Y) trigger_cmd(X) SEMI. {
+  if( Y ){
+    Y->pLast->pNext = X;
+  }else{
+    Y = X;
+  }
+  Y->pLast = X;
+  A = Y;
+}
+trigger_cmd_list(A) ::= . { A = 0; }
+
+%type trigger_cmd {TriggerStep*}
+%destructor trigger_cmd {sqlite3DeleteTriggerStep(pParse->db, $$);}
+// UPDATE 
+trigger_cmd(A) ::= UPDATE orconf(R) nm(X) SET setlist(Y) where_opt(Z).  
+               { A = sqlite3TriggerUpdateStep(pParse->db, &X, Y, Z, R); }
+
+// INSERT
+trigger_cmd(A) ::= insert_cmd(R) INTO nm(X) inscollist_opt(F) 
+                   VALUES LP itemlist(Y) RP.  
+               {A = sqlite3TriggerInsertStep(pParse->db, &X, F, Y, 0, R);}
+
+trigger_cmd(A) ::= insert_cmd(R) INTO nm(X) inscollist_opt(F) select(S).
+               {A = sqlite3TriggerInsertStep(pParse->db, &X, F, 0, S, R);}
+
+// DELETE
+trigger_cmd(A) ::= DELETE FROM nm(X) where_opt(Y).
+               {A = sqlite3TriggerDeleteStep(pParse->db, &X, Y);}
+
+// SELECT
+trigger_cmd(A) ::= select(X).  {A = sqlite3TriggerSelectStep(pParse->db, X); }
+
+// The special RAISE expression that may occur in trigger programs
+expr(A) ::= RAISE(X) LP IGNORE RP(Y).  {
+  A = sqlite3PExpr(pParse, TK_RAISE, 0, 0, 0); 
+  if( A ){
+    A->iColumn = OE_Ignore;
+    sqlite3ExprSpan(A, &X, &Y);
+  }
+}
+expr(A) ::= RAISE(X) LP raisetype(T) COMMA nm(Z) RP(Y).  {
+  A = sqlite3PExpr(pParse, TK_RAISE, 0, 0, &Z); 
+  if( A ) {
+    A->iColumn = T;
+    sqlite3ExprSpan(A, &X, &Y);
+  }
+}
+%endif  !SQLITE_OMIT_TRIGGER
+
+%type raisetype {int}
+raisetype(A) ::= ROLLBACK.  {A = OE_Rollback;}
+raisetype(A) ::= ABORT.     {A = OE_Abort;}
+raisetype(A) ::= FAIL.      {A = OE_Fail;}
+
+
+////////////////////////  DROP TRIGGER statement //////////////////////////////
+%ifndef SQLITE_OMIT_TRIGGER
+cmd ::= DROP TRIGGER ifexists(NOERR) fullname(X). {
+  sqlite3DropTrigger(pParse,X,NOERR);
+}
+%endif  !SQLITE_OMIT_TRIGGER
+
+//////////////////////// ATTACH DATABASE file AS name /////////////////////////
+%ifndef SQLITE_OMIT_ATTACH
+cmd ::= ATTACH database_kw_opt expr(F) AS expr(D) key_opt(K). {
+  sqlite3Attach(pParse, F, D, K);
+}
+cmd ::= DETACH database_kw_opt expr(D). {
+  sqlite3Detach(pParse, D);
+}
+
+%type key_opt {Expr*}
+%destructor key_opt {sqlite3ExprDelete(pParse->db, $$);}
+key_opt(A) ::= .                     { A = 0; }
+key_opt(A) ::= KEY expr(X).          { A = X; }
+
+database_kw_opt ::= DATABASE.
+database_kw_opt ::= .
+%endif SQLITE_OMIT_ATTACH
+
+////////////////////////// REINDEX collation //////////////////////////////////
+%ifndef SQLITE_OMIT_REINDEX
+cmd ::= REINDEX.                {sqlite3Reindex(pParse, 0, 0);}
+cmd ::= REINDEX nm(X) dbnm(Y).  {sqlite3Reindex(pParse, &X, &Y);}
+%endif  SQLITE_OMIT_REINDEX
+
+/////////////////////////////////// ANALYZE ///////////////////////////////////
+%ifndef SQLITE_OMIT_ANALYZE
+cmd ::= ANALYZE.                {sqlite3Analyze(pParse, 0, 0);}
+cmd ::= ANALYZE nm(X) dbnm(Y).  {sqlite3Analyze(pParse, &X, &Y);}
+%endif
+
+//////////////////////// ALTER TABLE table ... ////////////////////////////////
+%ifndef SQLITE_OMIT_ALTERTABLE
+cmd ::= ALTER TABLE fullname(X) RENAME TO nm(Z). {
+  sqlite3AlterRenameTable(pParse,X,&Z);
+}
+cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt column(Y). {
+  sqlite3AlterFinishAddColumn(pParse, &Y);
+}
+add_column_fullname ::= fullname(X). {
+  sqlite3AlterBeginAddColumn(pParse, X);
+}
+kwcolumn_opt ::= .
+kwcolumn_opt ::= COLUMNKW.
+%endif  SQLITE_OMIT_ALTERTABLE
+
+//////////////////////// CREATE VIRTUAL TABLE ... /////////////////////////////
+%ifndef SQLITE_OMIT_VIRTUALTABLE
+cmd ::= create_vtab.                       {sqlite3VtabFinishParse(pParse,0);}
+cmd ::= create_vtab LP vtabarglist RP(X).  {sqlite3VtabFinishParse(pParse,&X);}
+create_vtab ::= CREATE VIRTUAL TABLE nm(X) dbnm(Y) USING nm(Z). {
+    sqlite3VtabBeginParse(pParse, &X, &Y, &Z);
+}
+vtabarglist ::= vtabarg.
+vtabarglist ::= vtabarglist COMMA vtabarg.
+vtabarg ::= .                       {sqlite3VtabArgInit(pParse);}
+vtabarg ::= vtabarg vtabargtoken.
+vtabargtoken ::= ANY(X).            {sqlite3VtabArgExtend(pParse,&X);}
+vtabargtoken ::= lp anylist RP(X).  {sqlite3VtabArgExtend(pParse,&X);}
+lp ::= LP(X).                       {sqlite3VtabArgExtend(pParse,&X);}
+anylist ::= .
+anylist ::= anylist ANY(X).         {sqlite3VtabArgExtend(pParse,&X);}
+%endif  SQLITE_OMIT_VIRTUALTABLE
diff --git a/third_party/sqlite/src/pragma.c b/third_party/sqlite/src/pragma.c
new file mode 100755
index 0000000..6ffc60d
--- /dev/null
+++ b/third_party/sqlite/src/pragma.c
@@ -0,0 +1,1329 @@
+/*
+** 2003 April 6
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code used to implement the PRAGMA command.
+**
+** $Id: pragma.c,v 1.183 2008/07/28 19:34:53 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+
+/* Ignore this whole file if pragmas are disabled
+*/
+#if !defined(SQLITE_OMIT_PRAGMA) && !defined(SQLITE_OMIT_PARSER)
+
+/*
+** Interpret the given string as a safety level.  Return 0 for OFF,
+** 1 for ON or NORMAL and 2 for FULL.  Return 1 for an empty or 
+** unrecognized string argument.
+**
+** Note that the values returned are one less that the values that
+** should be passed into sqlite3BtreeSetSafetyLevel().  The is done
+** to support legacy SQL code.  The safety level used to be boolean
+** and older scripts may have used numbers 0 for OFF and 1 for ON.
+*/
+static int getSafetyLevel(const char *z){
+                             /* 123456789 123456789 */
+  static const char zText[] = "onoffalseyestruefull";
+  static const u8 iOffset[] = {0, 1, 2, 4, 9, 12, 16};
+  static const u8 iLength[] = {2, 2, 3, 5, 3, 4, 4};
+  static const u8 iValue[] =  {1, 0, 0, 0, 1, 1, 2};
+  int i, n;
+  if( isdigit(*z) ){
+    return atoi(z);
+  }
+  n = strlen(z);
+  for(i=0; i<sizeof(iLength); i++){
+    if( iLength[i]==n && sqlite3StrNICmp(&zText[iOffset[i]],z,n)==0 ){
+      return iValue[i];
+    }
+  }
+  return 1;
+}
+
+/*
+** Interpret the given string as a boolean value.
+*/
+static int getBoolean(const char *z){
+  return getSafetyLevel(z)&1;
+}
+
+/*
+** Interpret the given string as a locking mode value.
+*/
+static int getLockingMode(const char *z){
+  if( z ){
+    if( 0==sqlite3StrICmp(z, "exclusive") ) return PAGER_LOCKINGMODE_EXCLUSIVE;
+    if( 0==sqlite3StrICmp(z, "normal") ) return PAGER_LOCKINGMODE_NORMAL;
+  }
+  return PAGER_LOCKINGMODE_QUERY;
+}
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+/*
+** Interpret the given string as an auto-vacuum mode value.
+**
+** The following strings, "none", "full" and "incremental" are 
+** acceptable, as are their numeric equivalents: 0, 1 and 2 respectively.
+*/
+static int getAutoVacuum(const char *z){
+  int i;
+  if( 0==sqlite3StrICmp(z, "none") ) return BTREE_AUTOVACUUM_NONE;
+  if( 0==sqlite3StrICmp(z, "full") ) return BTREE_AUTOVACUUM_FULL;
+  if( 0==sqlite3StrICmp(z, "incremental") ) return BTREE_AUTOVACUUM_INCR;
+  i = atoi(z);
+  return ((i>=0&&i<=2)?i:0);
+}
+#endif /* ifndef SQLITE_OMIT_AUTOVACUUM */
+
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+/*
+** Interpret the given string as a temp db location. Return 1 for file
+** backed temporary databases, 2 for the Red-Black tree in memory database
+** and 0 to use the compile-time default.
+*/
+static int getTempStore(const char *z){
+  if( z[0]>='0' && z[0]<='2' ){
+    return z[0] - '0';
+  }else if( sqlite3StrICmp(z, "file")==0 ){
+    return 1;
+  }else if( sqlite3StrICmp(z, "memory")==0 ){
+    return 2;
+  }else{
+    return 0;
+  }
+}
+#endif /* SQLITE_PAGER_PRAGMAS */
+
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+/*
+** Invalidate temp storage, either when the temp storage is changed
+** from default, or when 'file' and the temp_store_directory has changed
+*/
+static int invalidateTempStorage(Parse *pParse){
+  sqlite3 *db = pParse->db;
+  if( db->aDb[1].pBt!=0 ){
+    if( !db->autoCommit || sqlite3BtreeIsInReadTrans(db->aDb[1].pBt) ){
+      sqlite3ErrorMsg(pParse, "temporary storage cannot be changed "
+        "from within a transaction");
+      return SQLITE_ERROR;
+    }
+    sqlite3BtreeClose(db->aDb[1].pBt);
+    db->aDb[1].pBt = 0;
+    sqlite3ResetInternalSchema(db, 0);
+  }
+  return SQLITE_OK;
+}
+#endif /* SQLITE_PAGER_PRAGMAS */
+
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+/*
+** If the TEMP database is open, close it and mark the database schema
+** as needing reloading.  This must be done when using the SQLITE_TEMP_STORE
+** or DEFAULT_TEMP_STORE pragmas.
+*/
+static int changeTempStorage(Parse *pParse, const char *zStorageType){
+  int ts = getTempStore(zStorageType);
+  sqlite3 *db = pParse->db;
+  if( db->temp_store==ts ) return SQLITE_OK;
+  if( invalidateTempStorage( pParse ) != SQLITE_OK ){
+    return SQLITE_ERROR;
+  }
+  db->temp_store = ts;
+  return SQLITE_OK;
+}
+#endif /* SQLITE_PAGER_PRAGMAS */
+
+/*
+** Generate code to return a single integer value.
+*/
+static void returnSingleInt(Parse *pParse, const char *zLabel, int value){
+  Vdbe *v = sqlite3GetVdbe(pParse);
+  int mem = ++pParse->nMem;
+  sqlite3VdbeAddOp2(v, OP_Integer, value, mem);
+  if( pParse->explain==0 ){
+    sqlite3VdbeSetNumCols(v, 1);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLabel, P4_STATIC);
+  }
+  sqlite3VdbeAddOp2(v, OP_ResultRow, mem, 1);
+}
+
+#ifndef SQLITE_OMIT_FLAG_PRAGMAS
+/*
+** Check to see if zRight and zLeft refer to a pragma that queries
+** or changes one of the flags in db->flags.  Return 1 if so and 0 if not.
+** Also, implement the pragma.
+*/
+static int flagPragma(Parse *pParse, const char *zLeft, const char *zRight){
+  static const struct sPragmaType {
+    const char *zName;  /* Name of the pragma */
+    int mask;           /* Mask for the db->flags value */
+  } aPragma[] = {
+    { "full_column_names",        SQLITE_FullColNames  },
+    { "short_column_names",       SQLITE_ShortColNames },
+    { "count_changes",            SQLITE_CountRows     },
+    { "empty_result_callbacks",   SQLITE_NullCallback  },
+    { "legacy_file_format",       SQLITE_LegacyFileFmt },
+    { "fullfsync",                SQLITE_FullFSync     },
+#ifdef SQLITE_DEBUG
+    { "sql_trace",                SQLITE_SqlTrace      },
+    { "vdbe_listing",             SQLITE_VdbeListing   },
+    { "vdbe_trace",               SQLITE_VdbeTrace     },
+#endif
+#ifndef SQLITE_OMIT_CHECK
+    { "ignore_check_constraints", SQLITE_IgnoreChecks  },
+#endif
+    /* The following is VERY experimental */
+    { "writable_schema",          SQLITE_WriteSchema|SQLITE_RecoveryMode },
+    { "omit_readlock",            SQLITE_NoReadlock    },
+
+    /* TODO: Maybe it shouldn't be possible to change the ReadUncommitted
+    ** flag if there are any active statements. */
+    { "read_uncommitted",         SQLITE_ReadUncommitted },
+  };
+  int i;
+  const struct sPragmaType *p;
+  for(i=0, p=aPragma; i<sizeof(aPragma)/sizeof(aPragma[0]); i++, p++){
+    if( sqlite3StrICmp(zLeft, p->zName)==0 ){
+      sqlite3 *db = pParse->db;
+      Vdbe *v;
+      v = sqlite3GetVdbe(pParse);
+      if( v ){
+        if( zRight==0 ){
+          returnSingleInt(pParse, p->zName, (db->flags & p->mask)!=0 );
+        }else{
+          if( getBoolean(zRight) ){
+            db->flags |= p->mask;
+          }else{
+            db->flags &= ~p->mask;
+          }
+
+          /* Many of the flag-pragmas modify the code generated by the SQL 
+          ** compiler (eg. count_changes). So add an opcode to expire all
+          ** compiled SQL statements after modifying a pragma value.
+          */
+          sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
+        }
+      }
+
+      return 1;
+    }
+  }
+  return 0;
+}
+#endif /* SQLITE_OMIT_FLAG_PRAGMAS */
+
+/*
+** Process a pragma statement.  
+**
+** Pragmas are of this form:
+**
+**      PRAGMA [database.]id [= value]
+**
+** The identifier might also be a string.  The value is a string, and
+** identifier, or a number.  If minusFlag is true, then the value is
+** a number that was preceded by a minus sign.
+**
+** If the left side is "database.id" then pId1 is the database name
+** and pId2 is the id.  If the left side is just "id" then pId1 is the
+** id and pId2 is any empty string.
+*/
+void sqlite3Pragma(
+  Parse *pParse, 
+  Token *pId1,        /* First part of [database.]id field */
+  Token *pId2,        /* Second part of [database.]id field, or NULL */
+  Token *pValue,      /* Token for <value>, or NULL */
+  int minusFlag       /* True if a '-' sign preceded <value> */
+){
+  char *zLeft = 0;       /* Nul-terminated UTF-8 string <id> */
+  char *zRight = 0;      /* Nul-terminated UTF-8 string <value>, or NULL */
+  const char *zDb = 0;   /* The database name */
+  Token *pId;            /* Pointer to <id> token */
+  int iDb;               /* Database index for <database> */
+  sqlite3 *db = pParse->db;
+  Db *pDb;
+  Vdbe *v = pParse->pVdbe = sqlite3VdbeCreate(db);
+  if( v==0 ) return;
+  pParse->nMem = 2;
+
+  /* Interpret the [database.] part of the pragma statement. iDb is the
+  ** index of the database this pragma is being applied to in db.aDb[]. */
+  iDb = sqlite3TwoPartName(pParse, pId1, pId2, &pId);
+  if( iDb<0 ) return;
+  pDb = &db->aDb[iDb];
+
+  /* If the temp database has been explicitly named as part of the 
+  ** pragma, make sure it is open. 
+  */
+  if( iDb==1 && sqlite3OpenTempDatabase(pParse) ){
+    return;
+  }
+
+  zLeft = sqlite3NameFromToken(db, pId);
+  if( !zLeft ) return;
+  if( minusFlag ){
+    zRight = sqlite3MPrintf(db, "-%T", pValue);
+  }else{
+    zRight = sqlite3NameFromToken(db, pValue);
+  }
+
+  zDb = ((iDb>0)?pDb->zName:0);
+  if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){
+    goto pragma_out;
+  }
+ 
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+  /*
+  **  PRAGMA [database.]default_cache_size
+  **  PRAGMA [database.]default_cache_size=N
+  **
+  ** The first form reports the current persistent setting for the
+  ** page cache size.  The value returned is the maximum number of
+  ** pages in the page cache.  The second form sets both the current
+  ** page cache size value and the persistent page cache size value
+  ** stored in the database file.
+  **
+  ** The default cache size is stored in meta-value 2 of page 1 of the
+  ** database file.  The cache size is actually the absolute value of
+  ** this memory location.  The sign of meta-value 2 determines the
+  ** synchronous setting.  A negative value means synchronous is off
+  ** and a positive value means synchronous is on.
+  */
+  if( sqlite3StrICmp(zLeft,"default_cache_size")==0 ){
+    static const VdbeOpList getCacheSize[] = {
+      { OP_ReadCookie,  0, 1,        2},  /* 0 */
+      { OP_IfPos,       1, 6,        0},
+      { OP_Integer,     0, 2,        0},
+      { OP_Subtract,    1, 2,        1},
+      { OP_IfPos,       1, 6,        0},
+      { OP_Integer,     0, 1,        0},  /* 5 */
+      { OP_ResultRow,   1, 1,        0},
+    };
+    int addr;
+    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    sqlite3VdbeUsesBtree(v, iDb);
+    if( !zRight ){
+      sqlite3VdbeSetNumCols(v, 1);
+      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cache_size", P4_STATIC);
+      pParse->nMem += 2;
+      addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize);
+      sqlite3VdbeChangeP1(v, addr, iDb);
+      sqlite3VdbeChangeP1(v, addr+5, SQLITE_DEFAULT_CACHE_SIZE);
+    }else{
+      int size = atoi(zRight);
+      if( size<0 ) size = -size;
+      sqlite3BeginWriteOperation(pParse, 0, iDb);
+      sqlite3VdbeAddOp2(v, OP_Integer, size, 1);
+      sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, 2, 2);
+      addr = sqlite3VdbeAddOp2(v, OP_IfPos, 2, 0);
+      sqlite3VdbeAddOp2(v, OP_Integer, -size, 1);
+      sqlite3VdbeJumpHere(v, addr);
+      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, 2, 1);
+      pDb->pSchema->cache_size = size;
+      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
+    }
+  }else
+
+  /*
+  **  PRAGMA [database.]page_size
+  **  PRAGMA [database.]page_size=N
+  **
+  ** The first form reports the current setting for the
+  ** database page size in bytes.  The second form sets the
+  ** database page size value.  The value can only be set if
+  ** the database has not yet been created.
+  */
+  if( sqlite3StrICmp(zLeft,"page_size")==0 ){
+    Btree *pBt = pDb->pBt;
+    if( !zRight ){
+      int size = pBt ? sqlite3BtreeGetPageSize(pBt) : 0;
+      returnSingleInt(pParse, "page_size", size);
+    }else{
+      /* Malloc may fail when setting the page-size, as there is an internal
+      ** buffer that the pager module resizes using sqlite3_realloc().
+      */
+      db->nextPagesize = atoi(zRight);
+      if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, -1) ){
+        db->mallocFailed = 1;
+      }
+    }
+  }else
+
+  /*
+  **  PRAGMA [database.]max_page_count
+  **  PRAGMA [database.]max_page_count=N
+  **
+  ** The first form reports the current setting for the
+  ** maximum number of pages in the database file.  The 
+  ** second form attempts to change this setting.  Both
+  ** forms return the current setting.
+  */
+  if( sqlite3StrICmp(zLeft,"max_page_count")==0 ){
+    Btree *pBt = pDb->pBt;
+    int newMax = 0;
+    if( zRight ){
+      newMax = atoi(zRight);
+    }
+    if( pBt ){
+      newMax = sqlite3BtreeMaxPageCount(pBt, newMax);
+    }
+    returnSingleInt(pParse, "max_page_count", newMax);
+  }else
+
+  /*
+  **  PRAGMA [database.]page_count
+  **
+  ** Return the number of pages in the specified database.
+  */
+  if( sqlite3StrICmp(zLeft,"page_count")==0 ){
+    Vdbe *v;
+    int iReg;
+    v = sqlite3GetVdbe(pParse);
+    if( !v || sqlite3ReadSchema(pParse) ) goto pragma_out;
+    sqlite3CodeVerifySchema(pParse, iDb);
+    iReg = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Pagecount, iDb, iReg);
+    sqlite3VdbeAddOp2(v, OP_ResultRow, iReg, 1);
+    sqlite3VdbeSetNumCols(v, 1);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "page_count", P4_STATIC);
+  }else
+
+  /*
+  **  PRAGMA [database.]locking_mode
+  **  PRAGMA [database.]locking_mode = (normal|exclusive)
+  */
+  if( sqlite3StrICmp(zLeft,"locking_mode")==0 ){
+    const char *zRet = "normal";
+    int eMode = getLockingMode(zRight);
+
+    if( pId2->n==0 && eMode==PAGER_LOCKINGMODE_QUERY ){
+      /* Simple "PRAGMA locking_mode;" statement. This is a query for
+      ** the current default locking mode (which may be different to
+      ** the locking-mode of the main database).
+      */
+      eMode = db->dfltLockMode;
+    }else{
+      Pager *pPager;
+      if( pId2->n==0 ){
+        /* This indicates that no database name was specified as part
+        ** of the PRAGMA command. In this case the locking-mode must be
+        ** set on all attached databases, as well as the main db file.
+        **
+        ** Also, the sqlite3.dfltLockMode variable is set so that
+        ** any subsequently attached databases also use the specified
+        ** locking mode.
+        */
+        int ii;
+        assert(pDb==&db->aDb[0]);
+        for(ii=2; ii<db->nDb; ii++){
+          pPager = sqlite3BtreePager(db->aDb[ii].pBt);
+          sqlite3PagerLockingMode(pPager, eMode);
+        }
+        db->dfltLockMode = eMode;
+      }
+      pPager = sqlite3BtreePager(pDb->pBt);
+      eMode = sqlite3PagerLockingMode(pPager, eMode);
+    }
+
+    assert(eMode==PAGER_LOCKINGMODE_NORMAL||eMode==PAGER_LOCKINGMODE_EXCLUSIVE);
+    if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){
+      zRet = "exclusive";
+    }
+    sqlite3VdbeSetNumCols(v, 1);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "locking_mode", P4_STATIC);
+    sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zRet, 0);
+    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
+  }else
+
+  /*
+  **  PRAGMA [database.]journal_mode
+  **  PRAGMA [database.]journal_mode = (delete|persist|off)
+  */
+  if( sqlite3StrICmp(zLeft,"journal_mode")==0 ){
+    int eMode;
+    static const char *azModeName[] = {"delete", "persist", "off"};
+
+    if( zRight==0 ){
+      eMode = PAGER_JOURNALMODE_QUERY;
+    }else{
+      int n = strlen(zRight);
+      eMode = 2;
+      while( eMode>=0 && sqlite3StrNICmp(zRight, azModeName[eMode], n)!=0 ){
+        eMode--;
+      }
+    }
+    if( pId2->n==0 && eMode==PAGER_JOURNALMODE_QUERY ){
+      /* Simple "PRAGMA journal_mode;" statement. This is a query for
+      ** the current default journal mode (which may be different to
+      ** the journal-mode of the main database).
+      */
+      eMode = db->dfltJournalMode;
+    }else{
+      Pager *pPager;
+      if( pId2->n==0 ){
+        /* This indicates that no database name was specified as part
+        ** of the PRAGMA command. In this case the journal-mode must be
+        ** set on all attached databases, as well as the main db file.
+        **
+        ** Also, the sqlite3.dfltJournalMode variable is set so that
+        ** any subsequently attached databases also use the specified
+        ** journal mode.
+        */
+        int ii;
+        assert(pDb==&db->aDb[0]);
+        for(ii=1; ii<db->nDb; ii++){
+          if( db->aDb[ii].pBt ){
+            pPager = sqlite3BtreePager(db->aDb[ii].pBt);
+            sqlite3PagerJournalMode(pPager, eMode);
+          }
+        }
+        db->dfltJournalMode = eMode;
+      }
+      pPager = sqlite3BtreePager(pDb->pBt);
+      eMode = sqlite3PagerJournalMode(pPager, eMode);
+    }
+    assert( eMode==PAGER_JOURNALMODE_DELETE
+              || eMode==PAGER_JOURNALMODE_PERSIST
+              || eMode==PAGER_JOURNALMODE_OFF );
+    sqlite3VdbeSetNumCols(v, 1);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "journal_mode", P4_STATIC);
+    sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, 
+           azModeName[eMode], P4_STATIC);
+    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
+  }else
+
+  /*
+  **  PRAGMA [database.]journal_size_limit
+  **  PRAGMA [database.]journal_size_limit=N
+  **
+  ** Get or set the (boolean) value of the database 'auto-vacuum' parameter.
+  */
+  if( sqlite3StrICmp(zLeft,"journal_size_limit")==0 ){
+    Pager *pPager = sqlite3BtreePager(pDb->pBt);
+    i64 iLimit = -2;
+    if( zRight ){
+      int iLimit32 = atoi(zRight);
+      if( iLimit32<-1 ){
+        iLimit32 = -1;
+      }
+      iLimit = iLimit32;
+    }
+    iLimit = sqlite3PagerJournalSizeLimit(pPager, iLimit);
+    returnSingleInt(pParse, "journal_size_limit", (int)iLimit);
+  }else
+
+#endif /* SQLITE_OMIT_PAGER_PRAGMAS */
+
+  /*
+  **  PRAGMA [database.]auto_vacuum
+  **  PRAGMA [database.]auto_vacuum=N
+  **
+  ** Get or set the (boolean) value of the database 'auto-vacuum' parameter.
+  */
+#ifndef SQLITE_OMIT_AUTOVACUUM
+  if( sqlite3StrICmp(zLeft,"auto_vacuum")==0 ){
+    Btree *pBt = pDb->pBt;
+    if( sqlite3ReadSchema(pParse) ){
+      goto pragma_out;
+    }
+    if( !zRight ){
+      int auto_vacuum = 
+          pBt ? sqlite3BtreeGetAutoVacuum(pBt) : SQLITE_DEFAULT_AUTOVACUUM;
+      returnSingleInt(pParse, "auto_vacuum", auto_vacuum);
+    }else{
+      int eAuto = getAutoVacuum(zRight);
+      db->nextAutovac = eAuto;
+      if( eAuto>=0 ){
+        /* Call SetAutoVacuum() to set initialize the internal auto and
+        ** incr-vacuum flags. This is required in case this connection
+        ** creates the database file. It is important that it is created
+        ** as an auto-vacuum capable db.
+        */
+        int rc = sqlite3BtreeSetAutoVacuum(pBt, eAuto);
+        if( rc==SQLITE_OK && (eAuto==1 || eAuto==2) ){
+          /* When setting the auto_vacuum mode to either "full" or 
+          ** "incremental", write the value of meta[6] in the database
+          ** file. Before writing to meta[6], check that meta[3] indicates
+          ** that this really is an auto-vacuum capable database.
+          */
+          static const VdbeOpList setMeta6[] = {
+            { OP_Transaction,    0,               1,        0},    /* 0 */
+            { OP_ReadCookie,     0,               1,        3},    /* 1 */
+            { OP_If,             1,               0,        0},    /* 2 */
+            { OP_Halt,           SQLITE_OK,       OE_Abort, 0},    /* 3 */
+            { OP_Integer,        0,               1,        0},    /* 4 */
+            { OP_SetCookie,      0,               6,        1},    /* 5 */
+          };
+          int iAddr;
+          iAddr = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6);
+          sqlite3VdbeChangeP1(v, iAddr, iDb);
+          sqlite3VdbeChangeP1(v, iAddr+1, iDb);
+          sqlite3VdbeChangeP2(v, iAddr+2, iAddr+4);
+          sqlite3VdbeChangeP1(v, iAddr+4, eAuto-1);
+          sqlite3VdbeChangeP1(v, iAddr+5, iDb);
+          sqlite3VdbeUsesBtree(v, iDb);
+        }
+      }
+    }
+  }else
+#endif
+
+  /*
+  **  PRAGMA [database.]incremental_vacuum(N)
+  **
+  ** Do N steps of incremental vacuuming on a database.
+  */
+#ifndef SQLITE_OMIT_AUTOVACUUM
+  if( sqlite3StrICmp(zLeft,"incremental_vacuum")==0 ){
+    int iLimit, addr;
+    if( sqlite3ReadSchema(pParse) ){
+      goto pragma_out;
+    }
+    if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){
+      iLimit = 0x7fffffff;
+    }
+    sqlite3BeginWriteOperation(pParse, 0, iDb);
+    sqlite3VdbeAddOp2(v, OP_Integer, iLimit, 1);
+    addr = sqlite3VdbeAddOp1(v, OP_IncrVacuum, iDb);
+    sqlite3VdbeAddOp1(v, OP_ResultRow, 1);
+    sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
+    sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr);
+    sqlite3VdbeJumpHere(v, addr);
+  }else
+#endif
+
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+  /*
+  **  PRAGMA [database.]cache_size
+  **  PRAGMA [database.]cache_size=N
+  **
+  ** The first form reports the current local setting for the
+  ** page cache size.  The local setting can be different from
+  ** the persistent cache size value that is stored in the database
+  ** file itself.  The value returned is the maximum number of
+  ** pages in the page cache.  The second form sets the local
+  ** page cache size value.  It does not change the persistent
+  ** cache size stored on the disk so the cache size will revert
+  ** to its default value when the database is closed and reopened.
+  ** N should be a positive integer.
+  */
+  if( sqlite3StrICmp(zLeft,"cache_size")==0 ){
+    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    if( !zRight ){
+      returnSingleInt(pParse, "cache_size", pDb->pSchema->cache_size);
+    }else{
+      int size = atoi(zRight);
+      if( size<0 ) size = -size;
+      pDb->pSchema->cache_size = size;
+      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
+    }
+  }else
+
+  /*
+  **   PRAGMA temp_store
+  **   PRAGMA temp_store = "default"|"memory"|"file"
+  **
+  ** Return or set the local value of the temp_store flag.  Changing
+  ** the local value does not make changes to the disk file and the default
+  ** value will be restored the next time the database is opened.
+  **
+  ** Note that it is possible for the library compile-time options to
+  ** override this setting
+  */
+  if( sqlite3StrICmp(zLeft, "temp_store")==0 ){
+    if( !zRight ){
+      returnSingleInt(pParse, "temp_store", db->temp_store);
+    }else{
+      changeTempStorage(pParse, zRight);
+    }
+  }else
+
+  /*
+  **   PRAGMA temp_store_directory
+  **   PRAGMA temp_store_directory = ""|"directory_name"
+  **
+  ** Return or set the local value of the temp_store_directory flag.  Changing
+  ** the value sets a specific directory to be used for temporary files.
+  ** Setting to a null string reverts to the default temporary directory search.
+  ** If temporary directory is changed, then invalidateTempStorage.
+  **
+  */
+  if( sqlite3StrICmp(zLeft, "temp_store_directory")==0 ){
+    if( !zRight ){
+      if( sqlite3_temp_directory ){
+        sqlite3VdbeSetNumCols(v, 1);
+        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
+            "temp_store_directory", P4_STATIC);
+        sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_temp_directory, 0);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
+      }
+    }else{
+      if( zRight[0] ){
+        int res;
+        sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);
+        if( res==0 ){
+          sqlite3ErrorMsg(pParse, "not a writable directory");
+          goto pragma_out;
+        }
+      }
+      if( SQLITE_TEMP_STORE==0
+       || (SQLITE_TEMP_STORE==1 && db->temp_store<=1)
+       || (SQLITE_TEMP_STORE==2 && db->temp_store==1)
+      ){
+        invalidateTempStorage(pParse);
+      }
+      sqlite3_free(sqlite3_temp_directory);
+      if( zRight[0] ){
+        sqlite3_temp_directory = sqlite3DbStrDup(0, zRight);
+      }else{
+        sqlite3_temp_directory = 0;
+      }
+    }
+  }else
+
+  /*
+  **   PRAGMA [database.]synchronous
+  **   PRAGMA [database.]synchronous=OFF|ON|NORMAL|FULL
+  **
+  ** Return or set the local value of the synchronous flag.  Changing
+  ** the local value does not make changes to the disk file and the
+  ** default value will be restored the next time the database is
+  ** opened.
+  */
+  if( sqlite3StrICmp(zLeft,"synchronous")==0 ){
+    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    if( !zRight ){
+      returnSingleInt(pParse, "synchronous", pDb->safety_level-1);
+    }else{
+      if( !db->autoCommit ){
+        sqlite3ErrorMsg(pParse, 
+            "Safety level may not be changed inside a transaction");
+      }else{
+        pDb->safety_level = getSafetyLevel(zRight)+1;
+      }
+    }
+  }else
+#endif /* SQLITE_OMIT_PAGER_PRAGMAS */
+
+#ifndef SQLITE_OMIT_FLAG_PRAGMAS
+  if( flagPragma(pParse, zLeft, zRight) ){
+    /* The flagPragma() subroutine also generates any necessary code
+    ** there is nothing more to do here */
+  }else
+#endif /* SQLITE_OMIT_FLAG_PRAGMAS */
+
+#ifndef SQLITE_OMIT_SCHEMA_PRAGMAS
+  /*
+  **   PRAGMA table_info(<table>)
+  **
+  ** Return a single row for each column of the named table. The columns of
+  ** the returned data set are:
+  **
+  ** cid:        Column id (numbered from left to right, starting at 0)
+  ** name:       Column name
+  ** type:       Column declaration type.
+  ** notnull:    True if 'NOT NULL' is part of column declaration
+  ** dflt_value: The default value for the column, if any.
+  */
+  if( sqlite3StrICmp(zLeft, "table_info")==0 && zRight ){
+    Table *pTab;
+    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    pTab = sqlite3FindTable(db, zRight, zDb);
+    if( pTab ){
+      int i;
+      int nHidden = 0;
+      Column *pCol;
+      sqlite3VdbeSetNumCols(v, 6);
+      pParse->nMem = 6;
+      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cid", P4_STATIC);
+      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
+      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "type", P4_STATIC);
+      sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "notnull", P4_STATIC);
+      sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "dflt_value", P4_STATIC);
+      sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "pk", P4_STATIC);
+      sqlite3ViewGetColumnNames(pParse, pTab);
+      for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
+        const Token *pDflt;
+        if( IsHiddenColumn(pCol) ){
+          nHidden++;
+          continue;
+        }
+        sqlite3VdbeAddOp2(v, OP_Integer, i-nHidden, 1);
+        sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pCol->zName, 0);
+        sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
+           pCol->zType ? pCol->zType : "", 0);
+        sqlite3VdbeAddOp2(v, OP_Integer, pCol->notNull, 4);
+        if( pCol->pDflt && (pDflt = &pCol->pDflt->span)->z ){
+          sqlite3VdbeAddOp4(v, OP_String8, 0, 5, 0, (char*)pDflt->z, pDflt->n);
+        }else{
+          sqlite3VdbeAddOp2(v, OP_Null, 0, 5);
+        }
+        sqlite3VdbeAddOp2(v, OP_Integer, pCol->isPrimKey, 6);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 6);
+      }
+    }
+  }else
+
+  if( sqlite3StrICmp(zLeft, "index_info")==0 && zRight ){
+    Index *pIdx;
+    Table *pTab;
+    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    pIdx = sqlite3FindIndex(db, zRight, zDb);
+    if( pIdx ){
+      int i;
+      pTab = pIdx->pTable;
+      sqlite3VdbeSetNumCols(v, 3);
+      pParse->nMem = 3;
+      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", P4_STATIC);
+      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", P4_STATIC);
+      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", P4_STATIC);
+      for(i=0; i<pIdx->nColumn; i++){
+        int cnum = pIdx->aiColumn[i];
+        sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
+        sqlite3VdbeAddOp2(v, OP_Integer, cnum, 2);
+        assert( pTab->nCol>cnum );
+        sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pTab->aCol[cnum].zName, 0);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
+      }
+    }
+  }else
+
+  if( sqlite3StrICmp(zLeft, "index_list")==0 && zRight ){
+    Index *pIdx;
+    Table *pTab;
+    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    pTab = sqlite3FindTable(db, zRight, zDb);
+    if( pTab ){
+      v = sqlite3GetVdbe(pParse);
+      pIdx = pTab->pIndex;
+      if( pIdx ){
+        int i = 0; 
+        sqlite3VdbeSetNumCols(v, 3);
+        pParse->nMem = 3;
+        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
+        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
+        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", P4_STATIC);
+        while(pIdx){
+          sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
+          sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0);
+          sqlite3VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 3);
+          sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
+          ++i;
+          pIdx = pIdx->pNext;
+        }
+      }
+    }
+  }else
+
+  if( sqlite3StrICmp(zLeft, "database_list")==0 ){
+    int i;
+    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    sqlite3VdbeSetNumCols(v, 3);
+    pParse->nMem = 3;
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
+    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
+    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "file", P4_STATIC);
+    for(i=0; i<db->nDb; i++){
+      if( db->aDb[i].pBt==0 ) continue;
+      assert( db->aDb[i].zName!=0 );
+      sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
+      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, db->aDb[i].zName, 0);
+      sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
+           sqlite3BtreeGetFilename(db->aDb[i].pBt), 0);
+      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
+    }
+  }else
+
+  if( sqlite3StrICmp(zLeft, "collation_list")==0 ){
+    int i = 0;
+    HashElem *p;
+    sqlite3VdbeSetNumCols(v, 2);
+    pParse->nMem = 2;
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
+    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
+    for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
+      CollSeq *pColl = (CollSeq *)sqliteHashData(p);
+      sqlite3VdbeAddOp2(v, OP_Integer, i++, 1);
+      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pColl->zName, 0);
+      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
+    }
+  }else
+#endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */
+
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+  if( sqlite3StrICmp(zLeft, "foreign_key_list")==0 && zRight ){
+    FKey *pFK;
+    Table *pTab;
+    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    pTab = sqlite3FindTable(db, zRight, zDb);
+    if( pTab ){
+      v = sqlite3GetVdbe(pParse);
+      pFK = pTab->pFKey;
+      if( pFK ){
+        int i = 0; 
+        sqlite3VdbeSetNumCols(v, 5);
+        pParse->nMem = 5;
+        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "id", P4_STATIC);
+        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "seq", P4_STATIC);
+        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "table", P4_STATIC);
+        sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "from", P4_STATIC);
+        sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "to", P4_STATIC);
+        while(pFK){
+          int j;
+          for(j=0; j<pFK->nCol; j++){
+            char *zCol = pFK->aCol[j].zCol;
+            sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
+            sqlite3VdbeAddOp2(v, OP_Integer, j, 2);
+            sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pFK->zTo, 0);
+            sqlite3VdbeAddOp4(v, OP_String8, 0, 4, 0,
+                              pTab->aCol[pFK->aCol[j].iFrom].zName, 0);
+            sqlite3VdbeAddOp4(v, zCol ? OP_String8 : OP_Null, 0, 5, 0, zCol, 0);
+            sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 5);
+          }
+          ++i;
+          pFK = pFK->pNextFrom;
+        }
+      }
+    }
+  }else
+#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
+
+#ifndef NDEBUG
+  if( sqlite3StrICmp(zLeft, "parser_trace")==0 ){
+    if( zRight ){
+      if( getBoolean(zRight) ){
+        sqlite3ParserTrace(stderr, "parser: ");
+      }else{
+        sqlite3ParserTrace(0, 0);
+      }
+    }
+  }else
+#endif
+
+  /* Reinstall the LIKE and GLOB functions.  The variant of LIKE
+  ** used will be case sensitive or not depending on the RHS.
+  */
+  if( sqlite3StrICmp(zLeft, "case_sensitive_like")==0 ){
+    if( zRight ){
+      sqlite3RegisterLikeFunctions(db, getBoolean(zRight));
+    }
+  }else
+
+#ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX
+# define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100
+#endif
+
+#ifndef SQLITE_OMIT_INTEGRITY_CHECK
+  /* Pragma "quick_check" is an experimental reduced version of 
+  ** integrity_check designed to detect most database corruption
+  ** without most of the overhead of a full integrity-check.
+  */
+  if( sqlite3StrICmp(zLeft, "integrity_check")==0
+   || sqlite3StrICmp(zLeft, "quick_check")==0 
+  ){
+    int i, j, addr, mxErr;
+
+    /* Code that appears at the end of the integrity check.  If no error
+    ** messages have been generated, output OK.  Otherwise output the
+    ** error message
+    */
+    static const VdbeOpList endCode[] = {
+      { OP_AddImm,      1, 0,        0},    /* 0 */
+      { OP_IfNeg,       1, 0,        0},    /* 1 */
+      { OP_String8,     0, 3,        0},    /* 2 */
+      { OP_ResultRow,   3, 1,        0},
+    };
+
+    int isQuick = (zLeft[0]=='q');
+
+    /* Initialize the VDBE program */
+    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    pParse->nMem = 6;
+    sqlite3VdbeSetNumCols(v, 1);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", P4_STATIC);
+
+    /* Set the maximum error count */
+    mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
+    if( zRight ){
+      mxErr = atoi(zRight);
+      if( mxErr<=0 ){
+        mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
+      }
+    }
+    sqlite3VdbeAddOp2(v, OP_Integer, mxErr, 1);  /* reg[1] holds errors left */
+
+    /* Do an integrity check on each database file */
+    for(i=0; i<db->nDb; i++){
+      HashElem *x;
+      Hash *pTbls;
+      int cnt = 0;
+
+      if( OMIT_TEMPDB && i==1 ) continue;
+
+      sqlite3CodeVerifySchema(pParse, i);
+      addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1); /* Halt if out of errors */
+      sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
+      sqlite3VdbeJumpHere(v, addr);
+
+      /* Do an integrity check of the B-Tree
+      **
+      ** Begin by filling registers 2, 3, ... with the root pages numbers
+      ** for all tables and indices in the database.
+      */
+      pTbls = &db->aDb[i].pSchema->tblHash;
+      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
+        Table *pTab = sqliteHashData(x);
+        Index *pIdx;
+        sqlite3VdbeAddOp2(v, OP_Integer, pTab->tnum, 2+cnt);
+        cnt++;
+        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+          sqlite3VdbeAddOp2(v, OP_Integer, pIdx->tnum, 2+cnt);
+          cnt++;
+        }
+      }
+      if( cnt==0 ) continue;
+
+      /* Make sure sufficient number of registers have been allocated */
+      if( pParse->nMem < cnt+4 ){
+        pParse->nMem = cnt+4;
+      }
+
+      /* Do the b-tree integrity checks */
+      sqlite3VdbeAddOp3(v, OP_IntegrityCk, 2, cnt, 1);
+      sqlite3VdbeChangeP5(v, i);
+      addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2);
+      sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
+         sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zName),
+         P4_DYNAMIC);
+      sqlite3VdbeAddOp3(v, OP_Move, 2, 4, 1);
+      sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 2);
+      sqlite3VdbeAddOp2(v, OP_ResultRow, 2, 1);
+      sqlite3VdbeJumpHere(v, addr);
+
+      /* Make sure all the indices are constructed correctly.
+      */
+      for(x=sqliteHashFirst(pTbls); x && !isQuick; x=sqliteHashNext(x)){
+        Table *pTab = sqliteHashData(x);
+        Index *pIdx;
+        int loopTop;
+
+        if( pTab->pIndex==0 ) continue;
+        addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);  /* Stop if out of errors */
+        sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
+        sqlite3VdbeJumpHere(v, addr);
+        sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
+        sqlite3VdbeAddOp2(v, OP_Integer, 0, 2);  /* reg(2) will count entries */
+        loopTop = sqlite3VdbeAddOp2(v, OP_Rewind, 1, 0);
+        sqlite3VdbeAddOp2(v, OP_AddImm, 2, 1);   /* increment entry count */
+        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
+          int jmp2;
+          static const VdbeOpList idxErr[] = {
+            { OP_AddImm,      1, -1,  0},
+            { OP_String8,     0,  3,  0},    /* 1 */
+            { OP_Rowid,       1,  4,  0},
+            { OP_String8,     0,  5,  0},    /* 3 */
+            { OP_String8,     0,  6,  0},    /* 4 */
+            { OP_Concat,      4,  3,  3},
+            { OP_Concat,      5,  3,  3},
+            { OP_Concat,      6,  3,  3},
+            { OP_ResultRow,   3,  1,  0},
+            { OP_IfPos,       1,  0,  0},    /* 9 */
+            { OP_Halt,        0,  0,  0},
+          };
+          sqlite3GenerateIndexKey(pParse, pIdx, 1, 3, 1);
+          jmp2 = sqlite3VdbeAddOp3(v, OP_Found, j+2, 0, 3);
+          addr = sqlite3VdbeAddOpList(v, ArraySize(idxErr), idxErr);
+          sqlite3VdbeChangeP4(v, addr+1, "rowid ", P4_STATIC);
+          sqlite3VdbeChangeP4(v, addr+3, " missing from index ", P4_STATIC);
+          sqlite3VdbeChangeP4(v, addr+4, pIdx->zName, P4_STATIC);
+          sqlite3VdbeJumpHere(v, addr+9);
+          sqlite3VdbeJumpHere(v, jmp2);
+        }
+        sqlite3VdbeAddOp2(v, OP_Next, 1, loopTop+1);
+        sqlite3VdbeJumpHere(v, loopTop);
+        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
+          static const VdbeOpList cntIdx[] = {
+             { OP_Integer,      0,  3,  0},
+             { OP_Rewind,       0,  0,  0},  /* 1 */
+             { OP_AddImm,       3,  1,  0},
+             { OP_Next,         0,  0,  0},  /* 3 */
+             { OP_Eq,           2,  0,  3},  /* 4 */
+             { OP_AddImm,       1, -1,  0},
+             { OP_String8,      0,  2,  0},  /* 6 */
+             { OP_String8,      0,  3,  0},  /* 7 */
+             { OP_Concat,       3,  2,  2},
+             { OP_ResultRow,    2,  1,  0},
+          };
+          if( pIdx->tnum==0 ) continue;
+          addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);
+          sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
+          sqlite3VdbeJumpHere(v, addr);
+          addr = sqlite3VdbeAddOpList(v, ArraySize(cntIdx), cntIdx);
+          sqlite3VdbeChangeP1(v, addr+1, j+2);
+          sqlite3VdbeChangeP2(v, addr+1, addr+4);
+          sqlite3VdbeChangeP1(v, addr+3, j+2);
+          sqlite3VdbeChangeP2(v, addr+3, addr+2);
+          sqlite3VdbeJumpHere(v, addr+4);
+          sqlite3VdbeChangeP4(v, addr+6, 
+                     "wrong # of entries in index ", P4_STATIC);
+          sqlite3VdbeChangeP4(v, addr+7, pIdx->zName, P4_STATIC);
+        }
+      } 
+    }
+    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
+    sqlite3VdbeChangeP2(v, addr, -mxErr);
+    sqlite3VdbeJumpHere(v, addr+1);
+    sqlite3VdbeChangeP4(v, addr+2, "ok", P4_STATIC);
+  }else
+#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
+
+#ifndef SQLITE_OMIT_UTF16
+  /*
+  **   PRAGMA encoding
+  **   PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be"
+  **
+  ** In its first form, this pragma returns the encoding of the main
+  ** database. If the database is not initialized, it is initialized now.
+  **
+  ** The second form of this pragma is a no-op if the main database file
+  ** has not already been initialized. In this case it sets the default
+  ** encoding that will be used for the main database file if a new file
+  ** is created. If an existing main database file is opened, then the
+  ** default text encoding for the existing database is used.
+  ** 
+  ** In all cases new databases created using the ATTACH command are
+  ** created to use the same default text encoding as the main database. If
+  ** the main database has not been initialized and/or created when ATTACH
+  ** is executed, this is done before the ATTACH operation.
+  **
+  ** In the second form this pragma sets the text encoding to be used in
+  ** new database files created using this database handle. It is only
+  ** useful if invoked immediately after the main database i
+  */
+  if( sqlite3StrICmp(zLeft, "encoding")==0 ){
+    static const struct EncName {
+      char *zName;
+      u8 enc;
+    } encnames[] = {
+      { "UTF-8",    SQLITE_UTF8        },
+      { "UTF8",     SQLITE_UTF8        },
+      { "UTF-16le", SQLITE_UTF16LE     },
+      { "UTF16le",  SQLITE_UTF16LE     },
+      { "UTF-16be", SQLITE_UTF16BE     },
+      { "UTF16be",  SQLITE_UTF16BE     },
+      { "UTF-16",   0                  }, /* SQLITE_UTF16NATIVE */
+      { "UTF16",    0                  }, /* SQLITE_UTF16NATIVE */
+      { 0, 0 }
+    };
+    const struct EncName *pEnc;
+    if( !zRight ){    /* "PRAGMA encoding" */
+      if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+      sqlite3VdbeSetNumCols(v, 1);
+      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "encoding", P4_STATIC);
+      sqlite3VdbeAddOp2(v, OP_String8, 0, 1);
+      for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
+        if( pEnc->enc==ENC(pParse->db) ){
+          sqlite3VdbeChangeP4(v, -1, pEnc->zName, P4_STATIC);
+          break;
+        }
+      }
+      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
+    }else{                        /* "PRAGMA encoding = XXX" */
+      /* Only change the value of sqlite.enc if the database handle is not
+      ** initialized. If the main database exists, the new sqlite.enc value
+      ** will be overwritten when the schema is next loaded. If it does not
+      ** already exists, it will be created to use the new encoding value.
+      */
+      if( 
+        !(DbHasProperty(db, 0, DB_SchemaLoaded)) || 
+        DbHasProperty(db, 0, DB_Empty) 
+      ){
+        for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
+          if( 0==sqlite3StrICmp(zRight, pEnc->zName) ){
+            ENC(pParse->db) = pEnc->enc ? pEnc->enc : SQLITE_UTF16NATIVE;
+            break;
+          }
+        }
+        if( !pEnc->zName ){
+          sqlite3ErrorMsg(pParse, "unsupported encoding: %s", zRight);
+        }
+      }
+    }
+  }else
+#endif /* SQLITE_OMIT_UTF16 */
+
+#ifndef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
+  /*
+  **   PRAGMA [database.]schema_version
+  **   PRAGMA [database.]schema_version = <integer>
+  **
+  **   PRAGMA [database.]user_version
+  **   PRAGMA [database.]user_version = <integer>
+  **
+  ** The pragma's schema_version and user_version are used to set or get
+  ** the value of the schema-version and user-version, respectively. Both
+  ** the schema-version and the user-version are 32-bit signed integers
+  ** stored in the database header.
+  **
+  ** The schema-cookie is usually only manipulated internally by SQLite. It
+  ** is incremented by SQLite whenever the database schema is modified (by
+  ** creating or dropping a table or index). The schema version is used by
+  ** SQLite each time a query is executed to ensure that the internal cache
+  ** of the schema used when compiling the SQL query matches the schema of
+  ** the database against which the compiled query is actually executed.
+  ** Subverting this mechanism by using "PRAGMA schema_version" to modify
+  ** the schema-version is potentially dangerous and may lead to program
+  ** crashes or database corruption. Use with caution!
+  **
+  ** The user-version is not used internally by SQLite. It may be used by
+  ** applications for any purpose.
+  */
+  if( sqlite3StrICmp(zLeft, "schema_version")==0 
+   || sqlite3StrICmp(zLeft, "user_version")==0 
+   || sqlite3StrICmp(zLeft, "freelist_count")==0 
+  ){
+
+    int iCookie;   /* Cookie index. 0 for schema-cookie, 6 for user-cookie. */
+    sqlite3VdbeUsesBtree(v, iDb);
+    switch( zLeft[0] ){
+      case 's': case 'S':
+        iCookie = 0;
+        break;
+      case 'f': case 'F':
+        iCookie = 1;
+        iDb = (-1*(iDb+1));
+        assert(iDb<=0);
+        break;
+      default:
+        iCookie = 5;
+        break;
+    }
+
+    if( zRight && iDb>=0 ){
+      /* Write the specified cookie value */
+      static const VdbeOpList setCookie[] = {
+        { OP_Transaction,    0,  1,  0},    /* 0 */
+        { OP_Integer,        0,  1,  0},    /* 1 */
+        { OP_SetCookie,      0,  0,  1},    /* 2 */
+      };
+      int addr = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie);
+      sqlite3VdbeChangeP1(v, addr, iDb);
+      sqlite3VdbeChangeP1(v, addr+1, atoi(zRight));
+      sqlite3VdbeChangeP1(v, addr+2, iDb);
+      sqlite3VdbeChangeP2(v, addr+2, iCookie);
+    }else{
+      /* Read the specified cookie value */
+      static const VdbeOpList readCookie[] = {
+        { OP_ReadCookie,      0,  1,  0},    /* 0 */
+        { OP_ResultRow,       1,  1,  0}
+      };
+      int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie);
+      sqlite3VdbeChangeP1(v, addr, iDb);
+      sqlite3VdbeChangeP3(v, addr, iCookie);
+      sqlite3VdbeSetNumCols(v, 1);
+      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, P4_TRANSIENT);
+    }
+  }else
+#endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */
+
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
+  /*
+  ** Report the current state of file logs for all databases
+  */
+  if( sqlite3StrICmp(zLeft, "lock_status")==0 ){
+    static const char *const azLockName[] = {
+      "unlocked", "shared", "reserved", "pending", "exclusive"
+    };
+    int i;
+    Vdbe *v = sqlite3GetVdbe(pParse);
+    sqlite3VdbeSetNumCols(v, 2);
+    pParse->nMem = 2;
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", P4_STATIC);
+    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "status", P4_STATIC);
+    for(i=0; i<db->nDb; i++){
+      Btree *pBt;
+      Pager *pPager;
+      const char *zState = "unknown";
+      int j;
+      if( db->aDb[i].zName==0 ) continue;
+      sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, db->aDb[i].zName, P4_STATIC);
+      pBt = db->aDb[i].pBt;
+      if( pBt==0 || (pPager = sqlite3BtreePager(pBt))==0 ){
+        zState = "closed";
+      }else if( sqlite3_file_control(db, i ? db->aDb[i].zName : 0, 
+                                     SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
+         zState = azLockName[j];
+      }
+      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, zState, P4_STATIC);
+      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
+    }
+  }else
+#endif
+
+#ifdef SQLITE_SSE
+  /*
+  ** Check to see if the sqlite_statements table exists.  Create it
+  ** if it does not.
+  */
+  if( sqlite3StrICmp(zLeft, "create_sqlite_statement_table")==0 ){
+    extern int sqlite3CreateStatementsTable(Parse*);
+    sqlite3CreateStatementsTable(pParse);
+  }else
+#endif
+
+#if SQLITE_HAS_CODEC
+  if( sqlite3StrICmp(zLeft, "key")==0 ){
+    sqlite3_key(db, zRight, strlen(zRight));
+  }else
+#endif
+#if SQLITE_HAS_CODEC || defined(SQLITE_ENABLE_CEROD)
+  if( sqlite3StrICmp(zLeft, "activate_extensions")==0 ){
+#if SQLITE_HAS_CODEC
+    if( sqlite3StrNICmp(zRight, "see-", 4)==0 ){
+      extern void sqlite3_activate_see(const char*);
+      sqlite3_activate_see(&zRight[4]);
+    }
+#endif
+#ifdef SQLITE_ENABLE_CEROD
+    if( sqlite3StrNICmp(zRight, "cerod-", 6)==0 ){
+      extern void sqlite3_activate_cerod(const char*);
+      sqlite3_activate_cerod(&zRight[6]);
+    }
+#endif
+  }
+#endif
+
+  {}
+
+  if( v ){
+    /* Code an OP_Expire at the end of each PRAGMA program to cause
+    ** the VDBE implementing the pragma to expire. Most (all?) pragmas
+    ** are only valid for a single execution.
+    */
+    sqlite3VdbeAddOp2(v, OP_Expire, 1, 0);
+
+    /*
+    ** Reset the safety level, in case the fullfsync flag or synchronous
+    ** setting changed.
+    */
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+    if( db->autoCommit ){
+      sqlite3BtreeSetSafetyLevel(pDb->pBt, pDb->safety_level,
+                 (db->flags&SQLITE_FullFSync)!=0);
+    }
+#endif
+  }
+pragma_out:
+  sqlite3DbFree(db, zLeft);
+  sqlite3DbFree(db, zRight);
+}
+
+#endif /* SQLITE_OMIT_PRAGMA || SQLITE_OMIT_PARSER */
diff --git a/third_party/sqlite/src/prepare.c b/third_party/sqlite/src/prepare.c
new file mode 100755
index 0000000..ef49f0a
--- /dev/null
+++ b/third_party/sqlite/src/prepare.c
@@ -0,0 +1,813 @@
+/*
+** 2005 May 25
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the implementation of the sqlite3_prepare()
+** interface, and routines that contribute to loading the database schema
+** from disk.
+**
+** $Id: prepare.c,v 1.91 2008/08/02 03:50:39 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+
+/*
+** Fill the InitData structure with an error message that indicates
+** that the database is corrupt.
+*/
+static void corruptSchema(
+  InitData *pData,     /* Initialization context */
+  const char *zObj,    /* Object being parsed at the point of error */
+  const char *zExtra   /* Error information */
+){
+  if( !pData->db->mallocFailed ){
+    if( zObj==0 ) zObj = "?";
+    sqlite3SetString(pData->pzErrMsg, pData->db,
+       "malformed database schema (%s)", zObj);
+    if( zExtra && zExtra[0] ){
+      *pData->pzErrMsg = sqlite3MAppendf(pData->db, *pData->pzErrMsg, "%s - %s",
+                                  *pData->pzErrMsg, zExtra);
+    }
+  }
+  pData->rc = SQLITE_CORRUPT;
+}
+
+/*
+** This is the callback routine for the code that initializes the
+** database.  See sqlite3Init() below for additional information.
+** This routine is also called from the OP_ParseSchema opcode of the VDBE.
+**
+** Each callback contains the following information:
+**
+**     argv[0] = name of thing being created
+**     argv[1] = root page number for table or index. 0 for trigger or view.
+**     argv[2] = SQL text for the CREATE statement.
+**
+*/
+int sqlite3InitCallback(void *pInit, int argc, char **argv, char **azColName){
+  InitData *pData = (InitData*)pInit;
+  sqlite3 *db = pData->db;
+  int iDb = pData->iDb;
+
+  assert( sqlite3_mutex_held(db->mutex) );
+  pData->rc = SQLITE_OK;
+  DbClearProperty(db, iDb, DB_Empty);
+  if( db->mallocFailed ){
+    corruptSchema(pData, argv[0], 0);
+    return SQLITE_NOMEM;
+  }
+
+  assert( argc==3 );
+  if( argv==0 ) return 0;   /* Might happen if EMPTY_RESULT_CALLBACKS are on */
+  if( argv[1]==0 ){
+    corruptSchema(pData, argv[0], 0);
+    return 1;
+  }
+  assert( iDb>=0 && iDb<db->nDb );
+  if( argv[2] && argv[2][0] ){
+    /* Call the parser to process a CREATE TABLE, INDEX or VIEW.
+    ** But because db->init.busy is set to 1, no VDBE code is generated
+    ** or executed.  All the parser does is build the internal data
+    ** structures that describe the table, index, or view.
+    */
+    char *zErr;
+    int rc;
+    u8 lookasideEnabled;
+    assert( db->init.busy );
+    db->init.iDb = iDb;
+    db->init.newTnum = atoi(argv[1]);
+    lookasideEnabled = db->lookaside.bEnabled;
+    db->lookaside.bEnabled = 0;
+    rc = sqlite3_exec(db, argv[2], 0, 0, &zErr);
+    db->init.iDb = 0;
+    db->lookaside.bEnabled = lookasideEnabled;
+    assert( rc!=SQLITE_OK || zErr==0 );
+    if( SQLITE_OK!=rc ){
+      pData->rc = rc;
+      if( rc==SQLITE_NOMEM ){
+        db->mallocFailed = 1;
+      }else if( rc!=SQLITE_INTERRUPT ){
+        corruptSchema(pData, argv[0], zErr);
+      }
+      sqlite3DbFree(db, zErr);
+      return 1;
+    }
+  }else if( argv[0]==0 ){
+    corruptSchema(pData, 0, 0);
+  }else{
+    /* If the SQL column is blank it means this is an index that
+    ** was created to be the PRIMARY KEY or to fulfill a UNIQUE
+    ** constraint for a CREATE TABLE.  The index should have already
+    ** been created when we processed the CREATE TABLE.  All we have
+    ** to do here is record the root page number for that index.
+    */
+    Index *pIndex;
+    pIndex = sqlite3FindIndex(db, argv[0], db->aDb[iDb].zName);
+    if( pIndex==0 || pIndex->tnum!=0 ){
+      /* This can occur if there exists an index on a TEMP table which
+      ** has the same name as another index on a permanent index.  Since
+      ** the permanent table is hidden by the TEMP table, we can also
+      ** safely ignore the index on the permanent table.
+      */
+      /* Do Nothing */;
+    }else{
+      pIndex->tnum = atoi(argv[1]);
+    }
+  }
+  return 0;
+}
+
+/*
+** Attempt to read the database schema and initialize internal
+** data structures for a single database file.  The index of the
+** database file is given by iDb.  iDb==0 is used for the main
+** database.  iDb==1 should never be used.  iDb>=2 is used for
+** auxiliary databases.  Return one of the SQLITE_ error codes to
+** indicate success or failure.
+*/
+static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
+  int rc;
+  BtCursor *curMain;
+  int size;
+  Table *pTab;
+  Db *pDb;
+  char const *azArg[4];
+  int meta[10];
+  InitData initData;
+  char const *zMasterSchema;
+  char const *zMasterName = SCHEMA_TABLE(iDb);
+
+  /*
+  ** The master database table has a structure like this
+  */
+  static const char master_schema[] = 
+     "CREATE TABLE sqlite_master(\n"
+     "  type text,\n"
+     "  name text,\n"
+     "  tbl_name text,\n"
+     "  rootpage integer,\n"
+     "  sql text\n"
+     ")"
+  ;
+#ifndef SQLITE_OMIT_TEMPDB
+  static const char temp_master_schema[] = 
+     "CREATE TEMP TABLE sqlite_temp_master(\n"
+     "  type text,\n"
+     "  name text,\n"
+     "  tbl_name text,\n"
+     "  rootpage integer,\n"
+     "  sql text\n"
+     ")"
+  ;
+#else
+  #define temp_master_schema 0
+#endif
+
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( db->aDb[iDb].pSchema );
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
+
+  /* zMasterSchema and zInitScript are set to point at the master schema
+  ** and initialisation script appropriate for the database being
+  ** initialised. zMasterName is the name of the master table.
+  */
+  if( !OMIT_TEMPDB && iDb==1 ){
+    zMasterSchema = temp_master_schema;
+  }else{
+    zMasterSchema = master_schema;
+  }
+  zMasterName = SCHEMA_TABLE(iDb);
+
+  /* Construct the schema tables.  */
+  azArg[0] = zMasterName;
+  azArg[1] = "1";
+  azArg[2] = zMasterSchema;
+  azArg[3] = 0;
+  initData.db = db;
+  initData.iDb = iDb;
+  initData.pzErrMsg = pzErrMsg;
+  (void)sqlite3SafetyOff(db);
+  rc = sqlite3InitCallback(&initData, 3, (char **)azArg, 0);
+  (void)sqlite3SafetyOn(db);
+  if( rc ){
+    rc = initData.rc;
+    goto error_out;
+  }
+  pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
+  if( pTab ){
+    pTab->readOnly = 1;
+  }
+
+  /* Create a cursor to hold the database open
+  */
+  pDb = &db->aDb[iDb];
+  if( pDb->pBt==0 ){
+    if( !OMIT_TEMPDB && iDb==1 ){
+      DbSetProperty(db, 1, DB_SchemaLoaded);
+    }
+    return SQLITE_OK;
+  }
+  curMain = sqlite3MallocZero(sqlite3BtreeCursorSize());
+  if( !curMain ){
+    rc = SQLITE_NOMEM;
+    goto error_out;
+  }
+  sqlite3BtreeEnter(pDb->pBt);
+  rc = sqlite3BtreeCursor(pDb->pBt, MASTER_ROOT, 0, 0, curMain);
+  if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
+    sqlite3SetString(pzErrMsg, db, "%s", sqlite3ErrStr(rc));
+    goto initone_error_out;
+  }
+
+  /* Get the database meta information.
+  **
+  ** Meta values are as follows:
+  **    meta[0]   Schema cookie.  Changes with each schema change.
+  **    meta[1]   File format of schema layer.
+  **    meta[2]   Size of the page cache.
+  **    meta[3]   Use freelist if 0.  Autovacuum if greater than zero.
+  **    meta[4]   Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE
+  **    meta[5]   The user cookie. Used by the application.
+  **    meta[6]   Incremental-vacuum flag.
+  **    meta[7]
+  **    meta[8]
+  **    meta[9]
+  **
+  ** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to
+  ** the possible values of meta[4].
+  */
+  if( rc==SQLITE_OK ){
+    int i;
+    for(i=0; i<sizeof(meta)/sizeof(meta[0]); i++){
+      rc = sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
+      if( rc ){
+        sqlite3SetString(pzErrMsg, db, "%s", sqlite3ErrStr(rc));
+        goto initone_error_out;
+      }
+    }
+  }else{
+    memset(meta, 0, sizeof(meta));
+  }
+  pDb->pSchema->schema_cookie = meta[0];
+
+  /* If opening a non-empty database, check the text encoding. For the
+  ** main database, set sqlite3.enc to the encoding of the main database.
+  ** For an attached db, it is an error if the encoding is not the same
+  ** as sqlite3.enc.
+  */
+  if( meta[4] ){  /* text encoding */
+    if( iDb==0 ){
+      /* If opening the main database, set ENC(db). */
+      ENC(db) = (u8)meta[4];
+      db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0);
+    }else{
+      /* If opening an attached database, the encoding much match ENC(db) */
+      if( meta[4]!=ENC(db) ){
+        sqlite3SetString(pzErrMsg, db, "attached databases must use the same"
+            " text encoding as main database");
+        rc = SQLITE_ERROR;
+        goto initone_error_out;
+      }
+    }
+  }else{
+    DbSetProperty(db, iDb, DB_Empty);
+  }
+  pDb->pSchema->enc = ENC(db);
+
+  if( pDb->pSchema->cache_size==0 ){
+    size = meta[2];
+    if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; }
+    if( size<0 ) size = -size;
+    pDb->pSchema->cache_size = size;
+    sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
+  }
+
+  /*
+  ** file_format==1    Version 3.0.0.
+  ** file_format==2    Version 3.1.3.  // ALTER TABLE ADD COLUMN
+  ** file_format==3    Version 3.1.4.  // ditto but with non-NULL defaults
+  ** file_format==4    Version 3.3.0.  // DESC indices.  Boolean constants
+  */
+  pDb->pSchema->file_format = meta[1];
+  if( pDb->pSchema->file_format==0 ){
+    pDb->pSchema->file_format = 1;
+  }
+  if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){
+    sqlite3SetString(pzErrMsg, db, "unsupported file format");
+    rc = SQLITE_ERROR;
+    goto initone_error_out;
+  }
+
+  /* Ticket #2804:  When we open a database in the newer file format,
+  ** clear the legacy_file_format pragma flag so that a VACUUM will
+  ** not downgrade the database and thus invalidate any descending
+  ** indices that the user might have created.
+  */
+  if( iDb==0 && meta[1]>=4 ){
+    db->flags &= ~SQLITE_LegacyFileFmt;
+  }
+
+  /* Read the schema information out of the schema tables
+  */
+  assert( db->init.busy );
+  if( rc==SQLITE_EMPTY ){
+    /* For an empty database, there is nothing to read */
+    rc = SQLITE_OK;
+  }else{
+    char *zSql;
+    zSql = sqlite3MPrintf(db, 
+        "SELECT name, rootpage, sql FROM '%q'.%s",
+        db->aDb[iDb].zName, zMasterName);
+    (void)sqlite3SafetyOff(db);
+#ifndef SQLITE_OMIT_AUTHORIZATION
+    {
+      int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
+      xAuth = db->xAuth;
+      db->xAuth = 0;
+#endif
+      rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
+#ifndef SQLITE_OMIT_AUTHORIZATION
+      db->xAuth = xAuth;
+    }
+#endif
+    if( rc==SQLITE_ABORT ) rc = initData.rc;
+    (void)sqlite3SafetyOn(db);
+    sqlite3DbFree(db, zSql);
+#ifndef SQLITE_OMIT_ANALYZE
+    if( rc==SQLITE_OK ){
+      sqlite3AnalysisLoad(db, iDb);
+    }
+#endif
+  }
+  if( db->mallocFailed ){
+    rc = SQLITE_NOMEM;
+    sqlite3ResetInternalSchema(db, 0);
+  }
+  if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){
+    /* Black magic: If the SQLITE_RecoveryMode flag is set, then consider
+    ** the schema loaded, even if errors occured. In this situation the 
+    ** current sqlite3_prepare() operation will fail, but the following one
+    ** will attempt to compile the supplied statement against whatever subset
+    ** of the schema was loaded before the error occured. The primary
+    ** purpose of this is to allow access to the sqlite_master table
+    ** even when its contents have been corrupted.
+    */
+    DbSetProperty(db, iDb, DB_SchemaLoaded);
+    rc = SQLITE_OK;
+  }
+
+  /* Jump here for an error that occurs after successfully allocating
+  ** curMain and calling sqlite3BtreeEnter(). For an error that occurs
+  ** before that point, jump to error_out.
+  */
+initone_error_out:
+  sqlite3BtreeCloseCursor(curMain);
+  sqlite3_free(curMain);
+  sqlite3BtreeLeave(pDb->pBt);
+
+error_out:
+  if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
+    db->mallocFailed = 1;
+  }
+  return rc;
+}
+
+/*
+** Initialize all database files - the main database file, the file
+** used to store temporary tables, and any additional database files
+** created using ATTACH statements.  Return a success code.  If an
+** error occurs, write an error message into *pzErrMsg.
+**
+** After a database is initialized, the DB_SchemaLoaded bit is set
+** bit is set in the flags field of the Db structure. If the database
+** file was of zero-length, then the DB_Empty flag is also set.
+*/
+int sqlite3Init(sqlite3 *db, char **pzErrMsg){
+  int i, rc;
+  int commit_internal = !(db->flags&SQLITE_InternChanges);
+  
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( db->init.busy ) return SQLITE_OK;
+  rc = SQLITE_OK;
+  db->init.busy = 1;
+  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
+    if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue;
+    rc = sqlite3InitOne(db, i, pzErrMsg);
+    if( rc ){
+      sqlite3ResetInternalSchema(db, i);
+    }
+  }
+
+  /* Once all the other databases have been initialised, load the schema
+  ** for the TEMP database. This is loaded last, as the TEMP database
+  ** schema may contain references to objects in other databases.
+  */
+#ifndef SQLITE_OMIT_TEMPDB
+  if( rc==SQLITE_OK && db->nDb>1 && !DbHasProperty(db, 1, DB_SchemaLoaded) ){
+    rc = sqlite3InitOne(db, 1, pzErrMsg);
+    if( rc ){
+      sqlite3ResetInternalSchema(db, 1);
+    }
+  }
+#endif
+
+  db->init.busy = 0;
+  if( rc==SQLITE_OK && commit_internal ){
+    sqlite3CommitInternalChanges(db);
+  }
+
+  return rc; 
+}
+
+/*
+** This routine is a no-op if the database schema is already initialised.
+** Otherwise, the schema is loaded. An error code is returned.
+*/
+int sqlite3ReadSchema(Parse *pParse){
+  int rc = SQLITE_OK;
+  sqlite3 *db = pParse->db;
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( !db->init.busy ){
+    rc = sqlite3Init(db, &pParse->zErrMsg);
+  }
+  if( rc!=SQLITE_OK ){
+    pParse->rc = rc;
+    pParse->nErr++;
+  }
+  return rc;
+}
+
+
+/*
+** Check schema cookies in all databases.  If any cookie is out
+** of date, return 0.  If all schema cookies are current, return 1.
+*/
+static int schemaIsValid(sqlite3 *db){
+  int iDb;
+  int rc;
+  BtCursor *curTemp;
+  int cookie;
+  int allOk = 1;
+
+  curTemp = (BtCursor *)sqlite3Malloc(sqlite3BtreeCursorSize());
+  if( curTemp ){
+    assert( sqlite3_mutex_held(db->mutex) );
+    for(iDb=0; allOk && iDb<db->nDb; iDb++){
+      Btree *pBt;
+      pBt = db->aDb[iDb].pBt;
+      if( pBt==0 ) continue;
+      memset(curTemp, 0, sqlite3BtreeCursorSize());
+      rc = sqlite3BtreeCursor(pBt, MASTER_ROOT, 0, 0, curTemp);
+      if( rc==SQLITE_OK ){
+        rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&cookie);
+        if( rc==SQLITE_OK && cookie!=db->aDb[iDb].pSchema->schema_cookie ){
+          allOk = 0;
+        }
+        sqlite3BtreeCloseCursor(curTemp);
+      }
+      if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
+        db->mallocFailed = 1;
+      }
+    }
+    sqlite3_free(curTemp);
+  }else{
+    allOk = 0;
+    db->mallocFailed = 1;
+  }
+
+  return allOk;
+}
+
+/*
+** Convert a schema pointer into the iDb index that indicates
+** which database file in db->aDb[] the schema refers to.
+**
+** If the same database is attached more than once, the first
+** attached database is returned.
+*/
+int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){
+  int i = -1000000;
+
+  /* If pSchema is NULL, then return -1000000. This happens when code in 
+  ** expr.c is trying to resolve a reference to a transient table (i.e. one
+  ** created by a sub-select). In this case the return value of this 
+  ** function should never be used.
+  **
+  ** We return -1000000 instead of the more usual -1 simply because using
+  ** -1000000 as incorrectly using -1000000 index into db->aDb[] is much 
+  ** more likely to cause a segfault than -1 (of course there are assert()
+  ** statements too, but it never hurts to play the odds).
+  */
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( pSchema ){
+    for(i=0; i<db->nDb; i++){
+      if( db->aDb[i].pSchema==pSchema ){
+        break;
+      }
+    }
+    assert( i>=0 &&i>=0 &&  i<db->nDb );
+  }
+  return i;
+}
+
+/*
+** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
+*/
+static int sqlite3Prepare(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  int saveSqlFlag,          /* True to copy SQL text into the sqlite3_stmt */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  Parse sParse;
+  char *zErrMsg = 0;
+  int rc = SQLITE_OK;
+  int i;
+
+  assert( ppStmt );
+  *ppStmt = 0;
+  if( sqlite3SafetyOn(db) ){
+    return SQLITE_MISUSE;
+  }
+  assert( !db->mallocFailed );
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  /* If any attached database schemas are locked, do not proceed with
+  ** compilation. Instead return SQLITE_LOCKED immediately.
+  */
+  for(i=0; i<db->nDb; i++) {
+    Btree *pBt = db->aDb[i].pBt;
+    if( pBt ){
+      int rc;
+      rc = sqlite3BtreeSchemaLocked(pBt);
+      if( rc ){
+        const char *zDb = db->aDb[i].zName;
+        sqlite3Error(db, SQLITE_LOCKED, "database schema is locked: %s", zDb);
+        (void)sqlite3SafetyOff(db);
+        return sqlite3ApiExit(db, SQLITE_LOCKED);
+      }
+    }
+  }
+  
+  memset(&sParse, 0, sizeof(sParse));
+  sParse.db = db;
+  if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){
+    char *zSqlCopy;
+    int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
+    if( nBytes>mxLen ){
+      sqlite3Error(db, SQLITE_TOOBIG, "statement too long");
+      (void)sqlite3SafetyOff(db);
+      return sqlite3ApiExit(db, SQLITE_TOOBIG);
+    }
+    zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
+    if( zSqlCopy ){
+      sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg);
+      sqlite3DbFree(db, zSqlCopy);
+      sParse.zTail = &zSql[sParse.zTail-zSqlCopy];
+    }else{
+      sParse.zTail = &zSql[nBytes];
+    }
+  }else{
+    sqlite3RunParser(&sParse, zSql, &zErrMsg);
+  }
+
+  if( db->mallocFailed ){
+    sParse.rc = SQLITE_NOMEM;
+  }
+  if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;
+  if( sParse.checkSchema && !schemaIsValid(db) ){
+    sParse.rc = SQLITE_SCHEMA;
+  }
+  if( sParse.rc==SQLITE_SCHEMA ){
+    sqlite3ResetInternalSchema(db, 0);
+  }
+  if( db->mallocFailed ){
+    sParse.rc = SQLITE_NOMEM;
+  }
+  if( pzTail ){
+    *pzTail = sParse.zTail;
+  }
+  rc = sParse.rc;
+
+#ifndef SQLITE_OMIT_EXPLAIN
+  if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){
+    if( sParse.explain==2 ){
+      sqlite3VdbeSetNumCols(sParse.pVdbe, 3);
+      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "order", P4_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "from", P4_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "detail", P4_STATIC);
+    }else{
+      sqlite3VdbeSetNumCols(sParse.pVdbe, 8);
+      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "addr", P4_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "opcode", P4_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "p1", P4_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 3, COLNAME_NAME, "p2", P4_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 4, COLNAME_NAME, "p3", P4_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 5, COLNAME_NAME, "p4", P4_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 6, COLNAME_NAME, "p5", P4_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 7, COLNAME_NAME, "comment",P4_STATIC);
+    }
+  }
+#endif
+
+  if( sqlite3SafetyOff(db) ){
+    rc = SQLITE_MISUSE;
+  }
+
+  if( saveSqlFlag ){
+    sqlite3VdbeSetSql(sParse.pVdbe, zSql, sParse.zTail - zSql);
+  }
+  if( rc!=SQLITE_OK || db->mallocFailed ){
+    sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe);
+    assert(!(*ppStmt));
+  }else{
+    *ppStmt = (sqlite3_stmt*)sParse.pVdbe;
+  }
+
+  if( zErrMsg ){
+    sqlite3Error(db, rc, "%s", zErrMsg);
+    sqlite3DbFree(db, zErrMsg);
+  }else{
+    sqlite3Error(db, rc, 0);
+  }
+
+  rc = sqlite3ApiExit(db, rc);
+  assert( (rc&db->errMask)==rc );
+  return rc;
+}
+static int sqlite3LockAndPrepare(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  int saveSqlFlag,          /* True to copy SQL text into the sqlite3_stmt */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE;
+  }
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, ppStmt, pzTail);
+  sqlite3BtreeLeaveAll(db);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Rerun the compilation of a statement after a schema change.
+** Return true if the statement was recompiled successfully.
+** Return false if there is an error of some kind.
+*/
+int sqlite3Reprepare(Vdbe *p){
+  int rc;
+  sqlite3_stmt *pNew;
+  const char *zSql;
+  sqlite3 *db;
+
+  assert( sqlite3_mutex_held(sqlite3VdbeDb(p)->mutex) );
+  zSql = sqlite3_sql((sqlite3_stmt *)p);
+  assert( zSql!=0 );  /* Reprepare only called for prepare_v2() statements */
+  db = sqlite3VdbeDb(p);
+  assert( sqlite3_mutex_held(db->mutex) );
+  rc = sqlite3LockAndPrepare(db, zSql, -1, 0, &pNew, 0);
+  if( rc ){
+    if( rc==SQLITE_NOMEM ){
+      db->mallocFailed = 1;
+    }
+    assert( pNew==0 );
+    return 0;
+  }else{
+    assert( pNew!=0 );
+  }
+  sqlite3VdbeSwap((Vdbe*)pNew, p);
+  sqlite3_transfer_bindings(pNew, (sqlite3_stmt*)p);
+  sqlite3VdbeResetStepResult((Vdbe*)pNew);
+  sqlite3VdbeFinalize((Vdbe*)pNew);
+  return 1;
+}
+
+
+/*
+** Two versions of the official API.  Legacy and new use.  In the legacy
+** version, the original SQL text is not saved in the prepared statement
+** and so if a schema change occurs, SQLITE_SCHEMA is returned by
+** sqlite3_step().  In the new version, the original SQL text is retained
+** and the statement is automatically recompiled if an schema change
+** occurs.
+*/
+int sqlite3_prepare(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  rc = sqlite3LockAndPrepare(db,zSql,nBytes,0,ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
+  return rc;
+}
+int sqlite3_prepare_v2(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  rc = sqlite3LockAndPrepare(db,zSql,nBytes,1,ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
+  return rc;
+}
+
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
+*/
+static int sqlite3Prepare16(
+  sqlite3 *db,              /* Database handle. */ 
+  const void *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  int saveSqlFlag,          /* True to save SQL text into the sqlite3_stmt */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const void **pzTail       /* OUT: End of parsed string */
+){
+  /* This function currently works by first transforming the UTF-16
+  ** encoded string to UTF-8, then invoking sqlite3_prepare(). The
+  ** tricky bit is figuring out the pointer to return in *pzTail.
+  */
+  char *zSql8;
+  const char *zTail8 = 0;
+  int rc = SQLITE_OK;
+
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE;
+  }
+  sqlite3_mutex_enter(db->mutex);
+  zSql8 = sqlite3Utf16to8(db, zSql, nBytes);
+  if( zSql8 ){
+    rc = sqlite3LockAndPrepare(db, zSql8, -1, saveSqlFlag, ppStmt, &zTail8);
+  }
+
+  if( zTail8 && pzTail ){
+    /* If sqlite3_prepare returns a tail pointer, we calculate the
+    ** equivalent pointer into the UTF-16 string by counting the unicode
+    ** characters between zSql8 and zTail8, and then returning a pointer
+    ** the same number of characters into the UTF-16 string.
+    */
+    int chars_parsed = sqlite3Utf8CharLen(zSql8, zTail8-zSql8);
+    *pzTail = (u8 *)zSql + sqlite3Utf16ByteLen(zSql, chars_parsed);
+  }
+  sqlite3DbFree(db, zSql8); 
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Two versions of the official API.  Legacy and new use.  In the legacy
+** version, the original SQL text is not saved in the prepared statement
+** and so if a schema change occurs, SQLITE_SCHEMA is returned by
+** sqlite3_step().  In the new version, the original SQL text is retained
+** and the statement is automatically recompiled if an schema change
+** occurs.
+*/
+int sqlite3_prepare16(
+  sqlite3 *db,              /* Database handle. */ 
+  const void *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const void **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  rc = sqlite3Prepare16(db,zSql,nBytes,0,ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
+  return rc;
+}
+int sqlite3_prepare16_v2(
+  sqlite3 *db,              /* Database handle. */ 
+  const void *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const void **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  rc = sqlite3Prepare16(db,zSql,nBytes,1,ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
+  return rc;
+}
+
+#endif /* SQLITE_OMIT_UTF16 */
diff --git a/third_party/sqlite/src/printf.c b/third_party/sqlite/src/printf.c
new file mode 100755
index 0000000..b88a7d8
--- /dev/null
+++ b/third_party/sqlite/src/printf.c
@@ -0,0 +1,934 @@
+/*
+** The "printf" code that follows dates from the 1980's.  It is in
+** the public domain.  The original comments are included here for
+** completeness.  They are very out-of-date but might be useful as
+** an historical reference.  Most of the "enhancements" have been backed
+** out so that the functionality is now the same as standard printf().
+**
+** $Id: printf.c,v 1.93 2008/07/28 19:34:53 drh Exp $
+**
+**************************************************************************
+**
+** The following modules is an enhanced replacement for the "printf" subroutines
+** found in the standard C library.  The following enhancements are
+** supported:
+**
+**      +  Additional functions.  The standard set of "printf" functions
+**         includes printf, fprintf, sprintf, vprintf, vfprintf, and
+**         vsprintf.  This module adds the following:
+**
+**           *  snprintf -- Works like sprintf, but has an extra argument
+**                          which is the size of the buffer written to.
+**
+**           *  mprintf --  Similar to sprintf.  Writes output to memory
+**                          obtained from malloc.
+**
+**           *  xprintf --  Calls a function to dispose of output.
+**
+**           *  nprintf --  No output, but returns the number of characters
+**                          that would have been output by printf.
+**
+**           *  A v- version (ex: vsnprintf) of every function is also
+**              supplied.
+**
+**      +  A few extensions to the formatting notation are supported:
+**
+**           *  The "=" flag (similar to "-") causes the output to be
+**              be centered in the appropriately sized field.
+**
+**           *  The %b field outputs an integer in binary notation.
+**
+**           *  The %c field now accepts a precision.  The character output
+**              is repeated by the number of times the precision specifies.
+**
+**           *  The %' field works like %c, but takes as its character the
+**              next character of the format string, instead of the next
+**              argument.  For example,  printf("%.78'-")  prints 78 minus
+**              signs, the same as  printf("%.78c",'-').
+**
+**      +  When compiled using GCC on a SPARC, this version of printf is
+**         faster than the library printf for SUN OS 4.1.
+**
+**      +  All functions are fully reentrant.
+**
+*/
+#include "sqliteInt.h"
+
+/*
+** Conversion types fall into various categories as defined by the
+** following enumeration.
+*/
+#define etRADIX       1 /* Integer types.  %d, %x, %o, and so forth */
+#define etFLOAT       2 /* Floating point.  %f */
+#define etEXP         3 /* Exponentional notation. %e and %E */
+#define etGENERIC     4 /* Floating or exponential, depending on exponent. %g */
+#define etSIZE        5 /* Return number of characters processed so far. %n */
+#define etSTRING      6 /* Strings. %s */
+#define etDYNSTRING   7 /* Dynamically allocated strings. %z */
+#define etPERCENT     8 /* Percent symbol. %% */
+#define etCHARX       9 /* Characters. %c */
+/* The rest are extensions, not normally found in printf() */
+#define etSQLESCAPE  10 /* Strings with '\'' doubled.  %q */
+#define etSQLESCAPE2 11 /* Strings with '\'' doubled and enclosed in '',
+                          NULL pointers replaced by SQL NULL.  %Q */
+#define etTOKEN      12 /* a pointer to a Token structure */
+#define etSRCLIST    13 /* a pointer to a SrcList */
+#define etPOINTER    14 /* The %p conversion */
+#define etSQLESCAPE3 15 /* %w -> Strings with '\"' doubled */
+#define etORDINAL    16 /* %r -> 1st, 2nd, 3rd, 4th, etc.  English only */
+
+
+/*
+** An "etByte" is an 8-bit unsigned value.
+*/
+typedef unsigned char etByte;
+
+/*
+** Each builtin conversion character (ex: the 'd' in "%d") is described
+** by an instance of the following structure
+*/
+typedef struct et_info {   /* Information about each format field */
+  char fmttype;            /* The format field code letter */
+  etByte base;             /* The base for radix conversion */
+  etByte flags;            /* One or more of FLAG_ constants below */
+  etByte type;             /* Conversion paradigm */
+  etByte charset;          /* Offset into aDigits[] of the digits string */
+  etByte prefix;           /* Offset into aPrefix[] of the prefix string */
+} et_info;
+
+/*
+** Allowed values for et_info.flags
+*/
+#define FLAG_SIGNED  1     /* True if the value to convert is signed */
+#define FLAG_INTERN  2     /* True if for internal use only */
+#define FLAG_STRING  4     /* Allow infinity precision */
+
+
+/*
+** The following table is searched linearly, so it is good to put the
+** most frequently used conversion types first.
+*/
+static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";
+static const char aPrefix[] = "-x0\000X0";
+static const et_info fmtinfo[] = {
+  {  'd', 10, 1, etRADIX,      0,  0 },
+  {  's',  0, 4, etSTRING,     0,  0 },
+  {  'g',  0, 1, etGENERIC,    30, 0 },
+  {  'z',  0, 4, etDYNSTRING,  0,  0 },
+  {  'q',  0, 4, etSQLESCAPE,  0,  0 },
+  {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },
+  {  'w',  0, 4, etSQLESCAPE3, 0,  0 },
+  {  'c',  0, 0, etCHARX,      0,  0 },
+  {  'o',  8, 0, etRADIX,      0,  2 },
+  {  'u', 10, 0, etRADIX,      0,  0 },
+  {  'x', 16, 0, etRADIX,      16, 1 },
+  {  'X', 16, 0, etRADIX,      0,  4 },
+#ifndef SQLITE_OMIT_FLOATING_POINT
+  {  'f',  0, 1, etFLOAT,      0,  0 },
+  {  'e',  0, 1, etEXP,        30, 0 },
+  {  'E',  0, 1, etEXP,        14, 0 },
+  {  'G',  0, 1, etGENERIC,    14, 0 },
+#endif
+  {  'i', 10, 1, etRADIX,      0,  0 },
+  {  'n',  0, 0, etSIZE,       0,  0 },
+  {  '%',  0, 0, etPERCENT,    0,  0 },
+  {  'p', 16, 0, etPOINTER,    0,  1 },
+  {  'T',  0, 2, etTOKEN,      0,  0 },
+  {  'S',  0, 2, etSRCLIST,    0,  0 },
+  {  'r', 10, 3, etORDINAL,    0,  0 },
+};
+#define etNINFO  (sizeof(fmtinfo)/sizeof(fmtinfo[0]))
+
+/*
+** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
+** conversions will work.
+*/
+#ifndef SQLITE_OMIT_FLOATING_POINT
+/*
+** "*val" is a double such that 0.1 <= *val < 10.0
+** Return the ascii code for the leading digit of *val, then
+** multiply "*val" by 10.0 to renormalize.
+**
+** Example:
+**     input:     *val = 3.14159
+**     output:    *val = 1.4159    function return = '3'
+**
+** The counter *cnt is incremented each time.  After counter exceeds
+** 16 (the number of significant digits in a 64-bit float) '0' is
+** always returned.
+*/
+static int et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
+  int digit;
+  LONGDOUBLE_TYPE d;
+  if( (*cnt)++ >= 16 ) return '0';
+  digit = (int)*val;
+  d = digit;
+  digit += '0';
+  *val = (*val - d)*10.0;
+  return digit;
+}
+#endif /* SQLITE_OMIT_FLOATING_POINT */
+
+/*
+** Append N space characters to the given string buffer.
+*/
+static void appendSpace(StrAccum *pAccum, int N){
+  static const char zSpaces[] = "                             ";
+  while( N>=sizeof(zSpaces)-1 ){
+    sqlite3StrAccumAppend(pAccum, zSpaces, sizeof(zSpaces)-1);
+    N -= sizeof(zSpaces)-1;
+  }
+  if( N>0 ){
+    sqlite3StrAccumAppend(pAccum, zSpaces, N);
+  }
+}
+
+/*
+** On machines with a small stack size, you can redefine the
+** SQLITE_PRINT_BUF_SIZE to be less than 350.  But beware - for
+** smaller values some %f conversions may go into an infinite loop.
+*/
+#ifndef SQLITE_PRINT_BUF_SIZE
+# define SQLITE_PRINT_BUF_SIZE 350
+#endif
+#define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */
+
+/*
+** The root program.  All variations call this core.
+**
+** INPUTS:
+**   func   This is a pointer to a function taking three arguments
+**            1. A pointer to anything.  Same as the "arg" parameter.
+**            2. A pointer to the list of characters to be output
+**               (Note, this list is NOT null terminated.)
+**            3. An integer number of characters to be output.
+**               (Note: This number might be zero.)
+**
+**   arg    This is the pointer to anything which will be passed as the
+**          first argument to "func".  Use it for whatever you like.
+**
+**   fmt    This is the format string, as in the usual print.
+**
+**   ap     This is a pointer to a list of arguments.  Same as in
+**          vfprint.
+**
+** OUTPUTS:
+**          The return value is the total number of characters sent to
+**          the function "func".  Returns -1 on a error.
+**
+** Note that the order in which automatic variables are declared below
+** seems to make a big difference in determining how fast this beast
+** will run.
+*/
+void sqlite3VXPrintf(
+  StrAccum *pAccum,                  /* Accumulate results here */
+  int useExtended,                   /* Allow extended %-conversions */
+  const char *fmt,                   /* Format string */
+  va_list ap                         /* arguments */
+){
+  int c;                     /* Next character in the format string */
+  char *bufpt;               /* Pointer to the conversion buffer */
+  int precision;             /* Precision of the current field */
+  int length;                /* Length of the field */
+  int idx;                   /* A general purpose loop counter */
+  int width;                 /* Width of the current field */
+  etByte flag_leftjustify;   /* True if "-" flag is present */
+  etByte flag_plussign;      /* True if "+" flag is present */
+  etByte flag_blanksign;     /* True if " " flag is present */
+  etByte flag_alternateform; /* True if "#" flag is present */
+  etByte flag_altform2;      /* True if "!" flag is present */
+  etByte flag_zeropad;       /* True if field width constant starts with zero */
+  etByte flag_long;          /* True if "l" flag is present */
+  etByte flag_longlong;      /* True if the "ll" flag is present */
+  etByte done;               /* Loop termination flag */
+  sqlite_uint64 longvalue;   /* Value for integer types */
+  LONGDOUBLE_TYPE realvalue; /* Value for real types */
+  const et_info *infop;      /* Pointer to the appropriate info structure */
+  char buf[etBUFSIZE];       /* Conversion buffer */
+  char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
+  etByte errorflag = 0;      /* True if an error is encountered */
+  etByte xtype;              /* Conversion paradigm */
+  char *zExtra;              /* Extra memory used for etTCLESCAPE conversions */
+#ifndef SQLITE_OMIT_FLOATING_POINT
+  int  exp, e2;              /* exponent of real numbers */
+  double rounder;            /* Used for rounding floating point values */
+  etByte flag_dp;            /* True if decimal point should be shown */
+  etByte flag_rtz;           /* True if trailing zeros should be removed */
+  etByte flag_exp;           /* True to force display of the exponent */
+  int nsd;                   /* Number of significant digits returned */
+#endif
+
+  length = 0;
+  bufpt = 0;
+  for(; (c=(*fmt))!=0; ++fmt){
+    if( c!='%' ){
+      int amt;
+      bufpt = (char *)fmt;
+      amt = 1;
+      while( (c=(*++fmt))!='%' && c!=0 ) amt++;
+      sqlite3StrAccumAppend(pAccum, bufpt, amt);
+      if( c==0 ) break;
+    }
+    if( (c=(*++fmt))==0 ){
+      errorflag = 1;
+      sqlite3StrAccumAppend(pAccum, "%", 1);
+      break;
+    }
+    /* Find out what flags are present */
+    flag_leftjustify = flag_plussign = flag_blanksign = 
+     flag_alternateform = flag_altform2 = flag_zeropad = 0;
+    done = 0;
+    do{
+      switch( c ){
+        case '-':   flag_leftjustify = 1;     break;
+        case '+':   flag_plussign = 1;        break;
+        case ' ':   flag_blanksign = 1;       break;
+        case '#':   flag_alternateform = 1;   break;
+        case '!':   flag_altform2 = 1;        break;
+        case '0':   flag_zeropad = 1;         break;
+        default:    done = 1;                 break;
+      }
+    }while( !done && (c=(*++fmt))!=0 );
+    /* Get the field width */
+    width = 0;
+    if( c=='*' ){
+      width = va_arg(ap,int);
+      if( width<0 ){
+        flag_leftjustify = 1;
+        width = -width;
+      }
+      c = *++fmt;
+    }else{
+      while( c>='0' && c<='9' ){
+        width = width*10 + c - '0';
+        c = *++fmt;
+      }
+    }
+    if( width > etBUFSIZE-10 ){
+      width = etBUFSIZE-10;
+    }
+    /* Get the precision */
+    if( c=='.' ){
+      precision = 0;
+      c = *++fmt;
+      if( c=='*' ){
+        precision = va_arg(ap,int);
+        if( precision<0 ) precision = -precision;
+        c = *++fmt;
+      }else{
+        while( c>='0' && c<='9' ){
+          precision = precision*10 + c - '0';
+          c = *++fmt;
+        }
+      }
+    }else{
+      precision = -1;
+    }
+    /* Get the conversion type modifier */
+    if( c=='l' ){
+      flag_long = 1;
+      c = *++fmt;
+      if( c=='l' ){
+        flag_longlong = 1;
+        c = *++fmt;
+      }else{
+        flag_longlong = 0;
+      }
+    }else{
+      flag_long = flag_longlong = 0;
+    }
+    /* Fetch the info entry for the field */
+    infop = 0;
+    for(idx=0; idx<etNINFO; idx++){
+      if( c==fmtinfo[idx].fmttype ){
+        infop = &fmtinfo[idx];
+        if( useExtended || (infop->flags & FLAG_INTERN)==0 ){
+          xtype = infop->type;
+        }else{
+          return;
+        }
+        break;
+      }
+    }
+    zExtra = 0;
+    if( infop==0 ){
+      return;
+    }
+
+
+    /* Limit the precision to prevent overflowing buf[] during conversion */
+    if( precision>etBUFSIZE-40 && (infop->flags & FLAG_STRING)==0 ){
+      precision = etBUFSIZE-40;
+    }
+
+    /*
+    ** At this point, variables are initialized as follows:
+    **
+    **   flag_alternateform          TRUE if a '#' is present.
+    **   flag_altform2               TRUE if a '!' is present.
+    **   flag_plussign               TRUE if a '+' is present.
+    **   flag_leftjustify            TRUE if a '-' is present or if the
+    **                               field width was negative.
+    **   flag_zeropad                TRUE if the width began with 0.
+    **   flag_long                   TRUE if the letter 'l' (ell) prefixed
+    **                               the conversion character.
+    **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
+    **                               the conversion character.
+    **   flag_blanksign              TRUE if a ' ' is present.
+    **   width                       The specified field width.  This is
+    **                               always non-negative.  Zero is the default.
+    **   precision                   The specified precision.  The default
+    **                               is -1.
+    **   xtype                       The class of the conversion.
+    **   infop                       Pointer to the appropriate info struct.
+    */
+    switch( xtype ){
+      case etPOINTER:
+        flag_longlong = sizeof(char*)==sizeof(i64);
+        flag_long = sizeof(char*)==sizeof(long int);
+        /* Fall through into the next case */
+      case etORDINAL:
+      case etRADIX:
+        if( infop->flags & FLAG_SIGNED ){
+          i64 v;
+          if( flag_longlong )   v = va_arg(ap,i64);
+          else if( flag_long )  v = va_arg(ap,long int);
+          else                  v = va_arg(ap,int);
+          if( v<0 ){
+            longvalue = -v;
+            prefix = '-';
+          }else{
+            longvalue = v;
+            if( flag_plussign )        prefix = '+';
+            else if( flag_blanksign )  prefix = ' ';
+            else                       prefix = 0;
+          }
+        }else{
+          if( flag_longlong )   longvalue = va_arg(ap,u64);
+          else if( flag_long )  longvalue = va_arg(ap,unsigned long int);
+          else                  longvalue = va_arg(ap,unsigned int);
+          prefix = 0;
+        }
+        if( longvalue==0 ) flag_alternateform = 0;
+        if( flag_zeropad && precision<width-(prefix!=0) ){
+          precision = width-(prefix!=0);
+        }
+        bufpt = &buf[etBUFSIZE-1];
+        if( xtype==etORDINAL ){
+          static const char zOrd[] = "thstndrd";
+          int x = longvalue % 10;
+          if( x>=4 || (longvalue/10)%10==1 ){
+            x = 0;
+          }
+          buf[etBUFSIZE-3] = zOrd[x*2];
+          buf[etBUFSIZE-2] = zOrd[x*2+1];
+          bufpt -= 2;
+        }
+        {
+          register const char *cset;      /* Use registers for speed */
+          register int base;
+          cset = &aDigits[infop->charset];
+          base = infop->base;
+          do{                                           /* Convert to ascii */
+            *(--bufpt) = cset[longvalue%base];
+            longvalue = longvalue/base;
+          }while( longvalue>0 );
+        }
+        length = &buf[etBUFSIZE-1]-bufpt;
+        for(idx=precision-length; idx>0; idx--){
+          *(--bufpt) = '0';                             /* Zero pad */
+        }
+        if( prefix ) *(--bufpt) = prefix;               /* Add sign */
+        if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
+          const char *pre;
+          char x;
+          pre = &aPrefix[infop->prefix];
+          for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
+        }
+        length = &buf[etBUFSIZE-1]-bufpt;
+        break;
+      case etFLOAT:
+      case etEXP:
+      case etGENERIC:
+        realvalue = va_arg(ap,double);
+#ifndef SQLITE_OMIT_FLOATING_POINT
+        if( precision<0 ) precision = 6;         /* Set default precision */
+        if( precision>etBUFSIZE/2-10 ) precision = etBUFSIZE/2-10;
+        if( realvalue<0.0 ){
+          realvalue = -realvalue;
+          prefix = '-';
+        }else{
+          if( flag_plussign )          prefix = '+';
+          else if( flag_blanksign )    prefix = ' ';
+          else                         prefix = 0;
+        }
+        if( xtype==etGENERIC && precision>0 ) precision--;
+#if 0
+        /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
+        for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
+#else
+        /* It makes more sense to use 0.5 */
+        for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1){}
+#endif
+        if( xtype==etFLOAT ) realvalue += rounder;
+        /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
+        exp = 0;
+        if( sqlite3IsNaN(realvalue) ){
+          bufpt = "NaN";
+          length = 3;
+          break;
+        }
+        if( realvalue>0.0 ){
+          while( realvalue>=1e32 && exp<=350 ){ realvalue *= 1e-32; exp+=32; }
+          while( realvalue>=1e8 && exp<=350 ){ realvalue *= 1e-8; exp+=8; }
+          while( realvalue>=10.0 && exp<=350 ){ realvalue *= 0.1; exp++; }
+          while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
+          while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
+          if( exp>350 ){
+            if( prefix=='-' ){
+              bufpt = "-Inf";
+            }else if( prefix=='+' ){
+              bufpt = "+Inf";
+            }else{
+              bufpt = "Inf";
+            }
+            length = strlen(bufpt);
+            break;
+          }
+        }
+        bufpt = buf;
+        /*
+        ** If the field type is etGENERIC, then convert to either etEXP
+        ** or etFLOAT, as appropriate.
+        */
+        flag_exp = xtype==etEXP;
+        if( xtype!=etFLOAT ){
+          realvalue += rounder;
+          if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
+        }
+        if( xtype==etGENERIC ){
+          flag_rtz = !flag_alternateform;
+          if( exp<-4 || exp>precision ){
+            xtype = etEXP;
+          }else{
+            precision = precision - exp;
+            xtype = etFLOAT;
+          }
+        }else{
+          flag_rtz = 0;
+        }
+        if( xtype==etEXP ){
+          e2 = 0;
+        }else{
+          e2 = exp;
+        }
+        nsd = 0;
+        flag_dp = (precision>0) | flag_alternateform | flag_altform2;
+        /* The sign in front of the number */
+        if( prefix ){
+          *(bufpt++) = prefix;
+        }
+        /* Digits prior to the decimal point */
+        if( e2<0 ){
+          *(bufpt++) = '0';
+        }else{
+          for(; e2>=0; e2--){
+            *(bufpt++) = et_getdigit(&realvalue,&nsd);
+          }
+        }
+        /* The decimal point */
+        if( flag_dp ){
+          *(bufpt++) = '.';
+        }
+        /* "0" digits after the decimal point but before the first
+        ** significant digit of the number */
+        for(e2++; e2<0; precision--, e2++){
+          assert( precision>0 );
+          *(bufpt++) = '0';
+        }
+        /* Significant digits after the decimal point */
+        while( (precision--)>0 ){
+          *(bufpt++) = et_getdigit(&realvalue,&nsd);
+        }
+        /* Remove trailing zeros and the "." if no digits follow the "." */
+        if( flag_rtz && flag_dp ){
+          while( bufpt[-1]=='0' ) *(--bufpt) = 0;
+          assert( bufpt>buf );
+          if( bufpt[-1]=='.' ){
+            if( flag_altform2 ){
+              *(bufpt++) = '0';
+            }else{
+              *(--bufpt) = 0;
+            }
+          }
+        }
+        /* Add the "eNNN" suffix */
+        if( flag_exp || xtype==etEXP ){
+          *(bufpt++) = aDigits[infop->charset];
+          if( exp<0 ){
+            *(bufpt++) = '-'; exp = -exp;
+          }else{
+            *(bufpt++) = '+';
+          }
+          if( exp>=100 ){
+            *(bufpt++) = (exp/100)+'0';                /* 100's digit */
+            exp %= 100;
+          }
+          *(bufpt++) = exp/10+'0';                     /* 10's digit */
+          *(bufpt++) = exp%10+'0';                     /* 1's digit */
+        }
+        *bufpt = 0;
+
+        /* The converted number is in buf[] and zero terminated. Output it.
+        ** Note that the number is in the usual order, not reversed as with
+        ** integer conversions. */
+        length = bufpt-buf;
+        bufpt = buf;
+
+        /* Special case:  Add leading zeros if the flag_zeropad flag is
+        ** set and we are not left justified */
+        if( flag_zeropad && !flag_leftjustify && length < width){
+          int i;
+          int nPad = width - length;
+          for(i=width; i>=nPad; i--){
+            bufpt[i] = bufpt[i-nPad];
+          }
+          i = prefix!=0;
+          while( nPad-- ) bufpt[i++] = '0';
+          length = width;
+        }
+#endif
+        break;
+      case etSIZE:
+        *(va_arg(ap,int*)) = pAccum->nChar;
+        length = width = 0;
+        break;
+      case etPERCENT:
+        buf[0] = '%';
+        bufpt = buf;
+        length = 1;
+        break;
+      case etCHARX:
+        c = buf[0] = va_arg(ap,int);
+        if( precision>=0 ){
+          for(idx=1; idx<precision; idx++) buf[idx] = c;
+          length = precision;
+        }else{
+          length =1;
+        }
+        bufpt = buf;
+        break;
+      case etSTRING:
+      case etDYNSTRING:
+        bufpt = va_arg(ap,char*);
+        if( bufpt==0 ){
+          bufpt = "";
+        }else if( xtype==etDYNSTRING ){
+          zExtra = bufpt;
+        }
+        if( precision>=0 ){
+          for(length=0; length<precision && bufpt[length]; length++){}
+        }else{
+          length = strlen(bufpt);
+        }
+        break;
+      case etSQLESCAPE:
+      case etSQLESCAPE2:
+      case etSQLESCAPE3: {
+        int i, j, n, ch, isnull;
+        int needQuote;
+        char q = ((xtype==etSQLESCAPE3)?'"':'\'');   /* Quote character */
+        char *escarg = va_arg(ap,char*);
+        isnull = escarg==0;
+        if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
+        for(i=n=0; (ch=escarg[i])!=0; i++){
+          if( ch==q )  n++;
+        }
+        needQuote = !isnull && xtype==etSQLESCAPE2;
+        n += i + 1 + needQuote*2;
+        if( n>etBUFSIZE ){
+          bufpt = zExtra = sqlite3Malloc( n );
+          if( bufpt==0 ) return;
+        }else{
+          bufpt = buf;
+        }
+        j = 0;
+        if( needQuote ) bufpt[j++] = q;
+        for(i=0; (ch=escarg[i])!=0; i++){
+          bufpt[j++] = ch;
+          if( ch==q ) bufpt[j++] = ch;
+        }
+        if( needQuote ) bufpt[j++] = q;
+        bufpt[j] = 0;
+        length = j;
+        /* The precision is ignored on %q and %Q */
+        /* if( precision>=0 && precision<length ) length = precision; */
+        break;
+      }
+      case etTOKEN: {
+        Token *pToken = va_arg(ap, Token*);
+        if( pToken ){
+          sqlite3StrAccumAppend(pAccum, (const char*)pToken->z, pToken->n);
+        }
+        length = width = 0;
+        break;
+      }
+      case etSRCLIST: {
+        SrcList *pSrc = va_arg(ap, SrcList*);
+        int k = va_arg(ap, int);
+        struct SrcList_item *pItem = &pSrc->a[k];
+        assert( k>=0 && k<pSrc->nSrc );
+        if( pItem->zDatabase ){
+          sqlite3StrAccumAppend(pAccum, pItem->zDatabase, -1);
+          sqlite3StrAccumAppend(pAccum, ".", 1);
+        }
+        sqlite3StrAccumAppend(pAccum, pItem->zName, -1);
+        length = width = 0;
+        break;
+      }
+    }/* End switch over the format type */
+    /*
+    ** The text of the conversion is pointed to by "bufpt" and is
+    ** "length" characters long.  The field width is "width".  Do
+    ** the output.
+    */
+    if( !flag_leftjustify ){
+      register int nspace;
+      nspace = width-length;
+      if( nspace>0 ){
+        appendSpace(pAccum, nspace);
+      }
+    }
+    if( length>0 ){
+      sqlite3StrAccumAppend(pAccum, bufpt, length);
+    }
+    if( flag_leftjustify ){
+      register int nspace;
+      nspace = width-length;
+      if( nspace>0 ){
+        appendSpace(pAccum, nspace);
+      }
+    }
+    if( zExtra ){
+      sqlite3_free(zExtra);
+    }
+  }/* End for loop over the format string */
+} /* End of function */
+
+/*
+** Append N bytes of text from z to the StrAccum object.
+*/
+void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
+  if( p->tooBig | p->mallocFailed ){
+    return;
+  }
+  if( N<0 ){
+    N = strlen(z);
+  }
+  if( N==0 ){
+    return;
+  }
+  if( p->nChar+N >= p->nAlloc ){
+    char *zNew;
+    if( !p->useMalloc ){
+      p->tooBig = 1;
+      N = p->nAlloc - p->nChar - 1;
+      if( N<=0 ){
+        return;
+      }
+    }else{
+      i64 szNew = p->nChar;
+      szNew += N + 1;
+      if( szNew > p->mxAlloc ){
+        sqlite3StrAccumReset(p);
+        p->tooBig = 1;
+        return;
+      }else{
+        p->nAlloc = szNew;
+      }
+      zNew = sqlite3DbMallocRaw(p->db, p->nAlloc );
+      if( zNew ){
+        memcpy(zNew, p->zText, p->nChar);
+        sqlite3StrAccumReset(p);
+        p->zText = zNew;
+      }else{
+        p->mallocFailed = 1;
+        sqlite3StrAccumReset(p);
+        return;
+      }
+    }
+  }
+  memcpy(&p->zText[p->nChar], z, N);
+  p->nChar += N;
+}
+
+/*
+** Finish off a string by making sure it is zero-terminated.
+** Return a pointer to the resulting string.  Return a NULL
+** pointer if any kind of error was encountered.
+*/
+char *sqlite3StrAccumFinish(StrAccum *p){
+  if( p->zText ){
+    p->zText[p->nChar] = 0;
+    if( p->useMalloc && p->zText==p->zBase ){
+      p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
+      if( p->zText ){
+        memcpy(p->zText, p->zBase, p->nChar+1);
+      }else{
+        p->mallocFailed = 1;
+      }
+    }
+  }
+  return p->zText;
+}
+
+/*
+** Reset an StrAccum string.  Reclaim all malloced memory.
+*/
+void sqlite3StrAccumReset(StrAccum *p){
+  if( p->zText!=p->zBase ){
+    sqlite3DbFree(p->db, p->zText);
+  }
+  p->zText = 0;
+}
+
+/*
+** Initialize a string accumulator
+*/
+void sqlite3StrAccumInit(StrAccum *p, char *zBase, int n, int mx){
+  p->zText = p->zBase = zBase;
+  p->db = 0;
+  p->nChar = 0;
+  p->nAlloc = n;
+  p->mxAlloc = mx;
+  p->useMalloc = 1;
+  p->tooBig = 0;
+  p->mallocFailed = 0;
+}
+
+/*
+** Print into memory obtained from sqliteMalloc().  Use the internal
+** %-conversion extensions.
+*/
+char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){
+  char *z;
+  char zBase[SQLITE_PRINT_BUF_SIZE];
+  StrAccum acc;
+  sqlite3StrAccumInit(&acc, zBase, sizeof(zBase),
+                      db ? db->aLimit[SQLITE_LIMIT_LENGTH] : SQLITE_MAX_LENGTH);
+  acc.db = db;
+  sqlite3VXPrintf(&acc, 1, zFormat, ap);
+  z = sqlite3StrAccumFinish(&acc);
+  if( acc.mallocFailed && db ){
+    db->mallocFailed = 1;
+  }
+  return z;
+}
+
+/*
+** Print into memory obtained from sqliteMalloc().  Use the internal
+** %-conversion extensions.
+*/
+char *sqlite3MPrintf(sqlite3 *db, const char *zFormat, ...){
+  va_list ap;
+  char *z;
+  va_start(ap, zFormat);
+  z = sqlite3VMPrintf(db, zFormat, ap);
+  va_end(ap);
+  return z;
+}
+
+/*
+** Like sqlite3MPrintf(), but call sqlite3DbFree() on zStr after formatting
+** the string and before returnning.  This routine is intended to be used
+** to modify an existing string.  For example:
+**
+**       x = sqlite3MPrintf(db, x, "prefix %s suffix", x);
+**
+*/
+char *sqlite3MAppendf(sqlite3 *db, char *zStr, const char *zFormat, ...){
+  va_list ap;
+  char *z;
+  va_start(ap, zFormat);
+  z = sqlite3VMPrintf(db, zFormat, ap);
+  va_end(ap);
+  sqlite3DbFree(db, zStr);
+  return z;
+}
+
+/*
+** Print into memory obtained from sqlite3_malloc().  Omit the internal
+** %-conversion extensions.
+*/
+char *sqlite3_vmprintf(const char *zFormat, va_list ap){
+  char *z;
+  char zBase[SQLITE_PRINT_BUF_SIZE];
+  StrAccum acc;
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  sqlite3StrAccumInit(&acc, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
+  sqlite3VXPrintf(&acc, 0, zFormat, ap);
+  z = sqlite3StrAccumFinish(&acc);
+  return z;
+}
+
+/*
+** Print into memory obtained from sqlite3_malloc()().  Omit the internal
+** %-conversion extensions.
+*/
+char *sqlite3_mprintf(const char *zFormat, ...){
+  va_list ap;
+  char *z;
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  va_start(ap, zFormat);
+  z = sqlite3_vmprintf(zFormat, ap);
+  va_end(ap);
+  return z;
+}
+
+/*
+** sqlite3_snprintf() works like snprintf() except that it ignores the
+** current locale settings.  This is important for SQLite because we
+** are not able to use a "," as the decimal point in place of "." as
+** specified by some locales.
+*/
+char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
+  char *z;
+  va_list ap;
+  StrAccum acc;
+
+  if( n<=0 ){
+    return zBuf;
+  }
+  sqlite3StrAccumInit(&acc, zBuf, n, 0);
+  acc.useMalloc = 0;
+  va_start(ap,zFormat);
+  sqlite3VXPrintf(&acc, 0, zFormat, ap);
+  va_end(ap);
+  z = sqlite3StrAccumFinish(&acc);
+  return z;
+}
+
+#if defined(SQLITE_DEBUG)
+/*
+** A version of printf() that understands %lld.  Used for debugging.
+** The printf() built into some versions of windows does not understand %lld
+** and segfaults if you give it a long long int.
+*/
+void sqlite3DebugPrintf(const char *zFormat, ...){
+  va_list ap;
+  StrAccum acc;
+  char zBuf[500];
+  sqlite3StrAccumInit(&acc, zBuf, sizeof(zBuf), 0);
+  acc.useMalloc = 0;
+  va_start(ap,zFormat);
+  sqlite3VXPrintf(&acc, 0, zFormat, ap);
+  va_end(ap);
+  sqlite3StrAccumFinish(&acc);
+  fprintf(stdout,"%s", zBuf);
+  fflush(stdout);
+}
+#endif
diff --git a/third_party/sqlite/src/random.c b/third_party/sqlite/src/random.c
new file mode 100755
index 0000000..f328232
--- /dev/null
+++ b/third_party/sqlite/src/random.c
@@ -0,0 +1,122 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code to implement a pseudo-random number
+** generator (PRNG) for SQLite.
+**
+** Random numbers are used by some of the database backends in order
+** to generate random integer keys for tables or random filenames.
+**
+** $Id: random.c,v 1.25 2008/06/19 01:03:18 drh Exp $
+*/
+#include "sqliteInt.h"
+
+
+/* All threads share a single random number generator.
+** This structure is the current state of the generator.
+*/
+static struct sqlite3PrngType {
+  unsigned char isInit;          /* True if initialized */
+  unsigned char i, j;            /* State variables */
+  unsigned char s[256];          /* State variables */
+} sqlite3Prng;
+
+/*
+** Get a single 8-bit random value from the RC4 PRNG.  The Mutex
+** must be held while executing this routine.
+**
+** Why not just use a library random generator like lrand48() for this?
+** Because the OP_NewRowid opcode in the VDBE depends on having a very
+** good source of random numbers.  The lrand48() library function may
+** well be good enough.  But maybe not.  Or maybe lrand48() has some
+** subtle problems on some systems that could cause problems.  It is hard
+** to know.  To minimize the risk of problems due to bad lrand48()
+** implementations, SQLite uses this random number generator based
+** on RC4, which we know works very well.
+**
+** (Later):  Actually, OP_NewRowid does not depend on a good source of
+** randomness any more.  But we will leave this code in all the same.
+*/
+static int randomByte(void){
+  unsigned char t;
+
+
+  /* Initialize the state of the random number generator once,
+  ** the first time this routine is called.  The seed value does
+  ** not need to contain a lot of randomness since we are not
+  ** trying to do secure encryption or anything like that...
+  **
+  ** Nothing in this file or anywhere else in SQLite does any kind of
+  ** encryption.  The RC4 algorithm is being used as a PRNG (pseudo-random
+  ** number generator) not as an encryption device.
+  */
+  if( !sqlite3Prng.isInit ){
+    int i;
+    char k[256];
+    sqlite3Prng.j = 0;
+    sqlite3Prng.i = 0;
+    sqlite3OsRandomness(sqlite3_vfs_find(0), 256, k);
+    for(i=0; i<256; i++){
+      sqlite3Prng.s[i] = i;
+    }
+    for(i=0; i<256; i++){
+      sqlite3Prng.j += sqlite3Prng.s[i] + k[i];
+      t = sqlite3Prng.s[sqlite3Prng.j];
+      sqlite3Prng.s[sqlite3Prng.j] = sqlite3Prng.s[i];
+      sqlite3Prng.s[i] = t;
+    }
+    sqlite3Prng.isInit = 1;
+  }
+
+  /* Generate and return single random byte
+  */
+  sqlite3Prng.i++;
+  t = sqlite3Prng.s[sqlite3Prng.i];
+  sqlite3Prng.j += t;
+  sqlite3Prng.s[sqlite3Prng.i] = sqlite3Prng.s[sqlite3Prng.j];
+  sqlite3Prng.s[sqlite3Prng.j] = t;
+  t += sqlite3Prng.s[sqlite3Prng.i];
+  return sqlite3Prng.s[t];
+}
+
+/*
+** Return N random bytes.
+*/
+void sqlite3_randomness(int N, void *pBuf){
+  unsigned char *zBuf = pBuf;
+#ifndef SQLITE_MUTEX_NOOP
+  sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_PRNG);
+#endif
+  sqlite3_mutex_enter(mutex);
+  while( N-- ){
+    *(zBuf++) = randomByte();
+  }
+  sqlite3_mutex_leave(mutex);
+}
+
+#ifndef SQLITE_OMIT_BUILTIN_TEST
+/*
+** For testing purposes, we sometimes want to preserve the state of
+** PRNG and restore the PRNG to its saved state at a later time.
+** The sqlite3_test_control() interface calls these routines to
+** control the PRNG.
+*/
+static struct sqlite3PrngType sqlite3SavedPrng;
+void sqlite3PrngSaveState(void){
+  memcpy(&sqlite3SavedPrng, &sqlite3Prng, sizeof(sqlite3Prng));
+}
+void sqlite3PrngRestoreState(void){
+  memcpy(&sqlite3Prng, &sqlite3SavedPrng, sizeof(sqlite3Prng));
+}
+void sqlite3PrngResetState(void){
+  sqlite3Prng.isInit = 0;
+}
+#endif /* SQLITE_OMIT_BUILTIN_TEST */
diff --git a/third_party/sqlite/src/select.c b/third_party/sqlite/src/select.c
new file mode 100755
index 0000000..5a8ddf0
--- /dev/null
+++ b/third_party/sqlite/src/select.c
@@ -0,0 +1,4292 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains C code routines that are called by the parser
+** to handle SELECT statements in SQLite.
+**
+** $Id: select.c,v 1.463 2008/08/04 03:51:24 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+
+
+/*
+** Delete all the content of a Select structure but do not deallocate
+** the select structure itself.
+*/
+static void clearSelect(sqlite3 *db, Select *p){
+  sqlite3ExprListDelete(db, p->pEList);
+  sqlite3SrcListDelete(db, p->pSrc);
+  sqlite3ExprDelete(db, p->pWhere);
+  sqlite3ExprListDelete(db, p->pGroupBy);
+  sqlite3ExprDelete(db, p->pHaving);
+  sqlite3ExprListDelete(db, p->pOrderBy);
+  sqlite3SelectDelete(db, p->pPrior);
+  sqlite3ExprDelete(db, p->pLimit);
+  sqlite3ExprDelete(db, p->pOffset);
+}
+
+/*
+** Initialize a SelectDest structure.
+*/
+void sqlite3SelectDestInit(SelectDest *pDest, int eDest, int iParm){
+  pDest->eDest = eDest;
+  pDest->iParm = iParm;
+  pDest->affinity = 0;
+  pDest->iMem = 0;
+  pDest->nMem = 0;
+}
+
+
+/*
+** Allocate a new Select structure and return a pointer to that
+** structure.
+*/
+Select *sqlite3SelectNew(
+  Parse *pParse,        /* Parsing context */
+  ExprList *pEList,     /* which columns to include in the result */
+  SrcList *pSrc,        /* the FROM clause -- which tables to scan */
+  Expr *pWhere,         /* the WHERE clause */
+  ExprList *pGroupBy,   /* the GROUP BY clause */
+  Expr *pHaving,        /* the HAVING clause */
+  ExprList *pOrderBy,   /* the ORDER BY clause */
+  int isDistinct,       /* true if the DISTINCT keyword is present */
+  Expr *pLimit,         /* LIMIT value.  NULL means not used */
+  Expr *pOffset         /* OFFSET value.  NULL means no offset */
+){
+  Select *pNew;
+  Select standin;
+  sqlite3 *db = pParse->db;
+  pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
+  assert( !pOffset || pLimit );   /* Can't have OFFSET without LIMIT. */
+  if( pNew==0 ){
+    pNew = &standin;
+    memset(pNew, 0, sizeof(*pNew));
+  }
+  if( pEList==0 ){
+    pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db,TK_ALL,0,0,0), 0);
+  }
+  pNew->pEList = pEList;
+  pNew->pSrc = pSrc;
+  pNew->pWhere = pWhere;
+  pNew->pGroupBy = pGroupBy;
+  pNew->pHaving = pHaving;
+  pNew->pOrderBy = pOrderBy;
+  pNew->isDistinct = isDistinct;
+  pNew->op = TK_SELECT;
+  assert( pOffset==0 || pLimit!=0 );
+  pNew->pLimit = pLimit;
+  pNew->pOffset = pOffset;
+  pNew->addrOpenEphm[0] = -1;
+  pNew->addrOpenEphm[1] = -1;
+  pNew->addrOpenEphm[2] = -1;
+  if( pNew==&standin) {
+    clearSelect(db, pNew);
+    pNew = 0;
+  }
+  return pNew;
+}
+
+/*
+** Delete the given Select structure and all of its substructures.
+*/
+void sqlite3SelectDelete(sqlite3 *db, Select *p){
+  if( p ){
+    clearSelect(db, p);
+    sqlite3DbFree(db, p);
+  }
+}
+
+/*
+** Given 1 to 3 identifiers preceeding the JOIN keyword, determine the
+** type of join.  Return an integer constant that expresses that type
+** in terms of the following bit values:
+**
+**     JT_INNER
+**     JT_CROSS
+**     JT_OUTER
+**     JT_NATURAL
+**     JT_LEFT
+**     JT_RIGHT
+**
+** A full outer join is the combination of JT_LEFT and JT_RIGHT.
+**
+** If an illegal or unsupported join type is seen, then still return
+** a join type, but put an error in the pParse structure.
+*/
+int sqlite3JoinType(Parse *pParse, Token *pA, Token *pB, Token *pC){
+  int jointype = 0;
+  Token *apAll[3];
+  Token *p;
+  static const struct {
+    const char zKeyword[8];
+    u8 nChar;
+    u8 code;
+  } keywords[] = {
+    { "natural", 7, JT_NATURAL },
+    { "left",    4, JT_LEFT|JT_OUTER },
+    { "right",   5, JT_RIGHT|JT_OUTER },
+    { "full",    4, JT_LEFT|JT_RIGHT|JT_OUTER },
+    { "outer",   5, JT_OUTER },
+    { "inner",   5, JT_INNER },
+    { "cross",   5, JT_INNER|JT_CROSS },
+  };
+  int i, j;
+  apAll[0] = pA;
+  apAll[1] = pB;
+  apAll[2] = pC;
+  for(i=0; i<3 && apAll[i]; i++){
+    p = apAll[i];
+    for(j=0; j<sizeof(keywords)/sizeof(keywords[0]); j++){
+      if( p->n==keywords[j].nChar 
+          && sqlite3StrNICmp((char*)p->z, keywords[j].zKeyword, p->n)==0 ){
+        jointype |= keywords[j].code;
+        break;
+      }
+    }
+    if( j>=sizeof(keywords)/sizeof(keywords[0]) ){
+      jointype |= JT_ERROR;
+      break;
+    }
+  }
+  if(
+     (jointype & (JT_INNER|JT_OUTER))==(JT_INNER|JT_OUTER) ||
+     (jointype & JT_ERROR)!=0
+  ){
+    const char *zSp = " ";
+    assert( pB!=0 );
+    if( pC==0 ){ zSp++; }
+    sqlite3ErrorMsg(pParse, "unknown or unsupported join type: "
+       "%T %T%s%T", pA, pB, zSp, pC);
+    jointype = JT_INNER;
+  }else if( jointype & JT_RIGHT ){
+    sqlite3ErrorMsg(pParse, 
+      "RIGHT and FULL OUTER JOINs are not currently supported");
+    jointype = JT_INNER;
+  }
+  return jointype;
+}
+
+/*
+** Return the index of a column in a table.  Return -1 if the column
+** is not contained in the table.
+*/
+static int columnIndex(Table *pTab, const char *zCol){
+  int i;
+  for(i=0; i<pTab->nCol; i++){
+    if( sqlite3StrICmp(pTab->aCol[i].zName, zCol)==0 ) return i;
+  }
+  return -1;
+}
+
+/*
+** Set the value of a token to a '\000'-terminated string.
+*/
+static void setToken(Token *p, const char *z){
+  p->z = (u8*)z;
+  p->n = z ? strlen(z) : 0;
+  p->dyn = 0;
+}
+
+/*
+** Set the token to the double-quoted and escaped version of the string pointed
+** to by z. For example;
+**
+**    {a"bc}  ->  {"a""bc"}
+*/
+static void setQuotedToken(Parse *pParse, Token *p, const char *z){
+
+  /* Check if the string contains any " characters. If it does, then
+  ** this function will malloc space to create a quoted version of
+  ** the string in. Otherwise, save a call to sqlite3MPrintf() by
+  ** just copying the pointer to the string.
+  */
+  const char *z2 = z;
+  while( *z2 ){
+    if( *z2=='"' ) break;
+    z2++;
+  }
+
+  if( *z2 ){
+    /* String contains " characters - copy and quote the string. */
+    p->z = (u8 *)sqlite3MPrintf(pParse->db, "\"%w\"", z);
+    if( p->z ){
+      p->n = strlen((char *)p->z);
+      p->dyn = 1;
+    }
+  }else{
+    /* String contains no " characters - copy the pointer. */
+    p->z = (u8*)z;
+    p->n = (z2 - z);
+    p->dyn = 0;
+  }
+}
+
+/*
+** Create an expression node for an identifier with the name of zName
+*/
+Expr *sqlite3CreateIdExpr(Parse *pParse, const char *zName){
+  Token dummy;
+  setToken(&dummy, zName);
+  return sqlite3PExpr(pParse, TK_ID, 0, 0, &dummy);
+}
+
+/*
+** Add a term to the WHERE expression in *ppExpr that requires the
+** zCol column to be equal in the two tables pTab1 and pTab2.
+*/
+static void addWhereTerm(
+  Parse *pParse,           /* Parsing context */
+  const char *zCol,        /* Name of the column */
+  const Table *pTab1,      /* First table */
+  const char *zAlias1,     /* Alias for first table.  May be NULL */
+  const Table *pTab2,      /* Second table */
+  const char *zAlias2,     /* Alias for second table.  May be NULL */
+  int iRightJoinTable,     /* VDBE cursor for the right table */
+  Expr **ppExpr,           /* Add the equality term to this expression */
+  int isOuterJoin          /* True if dealing with an OUTER join */
+){
+  Expr *pE1a, *pE1b, *pE1c;
+  Expr *pE2a, *pE2b, *pE2c;
+  Expr *pE;
+
+  pE1a = sqlite3CreateIdExpr(pParse, zCol);
+  pE2a = sqlite3CreateIdExpr(pParse, zCol);
+  if( zAlias1==0 ){
+    zAlias1 = pTab1->zName;
+  }
+  pE1b = sqlite3CreateIdExpr(pParse, zAlias1);
+  if( zAlias2==0 ){
+    zAlias2 = pTab2->zName;
+  }
+  pE2b = sqlite3CreateIdExpr(pParse, zAlias2);
+  pE1c = sqlite3PExpr(pParse, TK_DOT, pE1b, pE1a, 0);
+  pE2c = sqlite3PExpr(pParse, TK_DOT, pE2b, pE2a, 0);
+  pE = sqlite3PExpr(pParse, TK_EQ, pE1c, pE2c, 0);
+  if( pE && isOuterJoin ){
+    ExprSetProperty(pE, EP_FromJoin);
+    pE->iRightJoinTable = iRightJoinTable;
+  }
+  *ppExpr = sqlite3ExprAnd(pParse->db,*ppExpr, pE);
+}
+
+/*
+** Set the EP_FromJoin property on all terms of the given expression.
+** And set the Expr.iRightJoinTable to iTable for every term in the
+** expression.
+**
+** The EP_FromJoin property is used on terms of an expression to tell
+** the LEFT OUTER JOIN processing logic that this term is part of the
+** join restriction specified in the ON or USING clause and not a part
+** of the more general WHERE clause.  These terms are moved over to the
+** WHERE clause during join processing but we need to remember that they
+** originated in the ON or USING clause.
+**
+** The Expr.iRightJoinTable tells the WHERE clause processing that the
+** expression depends on table iRightJoinTable even if that table is not
+** explicitly mentioned in the expression.  That information is needed
+** for cases like this:
+**
+**    SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.b AND t1.x=5
+**
+** The where clause needs to defer the handling of the t1.x=5
+** term until after the t2 loop of the join.  In that way, a
+** NULL t2 row will be inserted whenever t1.x!=5.  If we do not
+** defer the handling of t1.x=5, it will be processed immediately
+** after the t1 loop and rows with t1.x!=5 will never appear in
+** the output, which is incorrect.
+*/
+static void setJoinExpr(Expr *p, int iTable){
+  while( p ){
+    ExprSetProperty(p, EP_FromJoin);
+    p->iRightJoinTable = iTable;
+    setJoinExpr(p->pLeft, iTable);
+    p = p->pRight;
+  } 
+}
+
+/*
+** This routine processes the join information for a SELECT statement.
+** ON and USING clauses are converted into extra terms of the WHERE clause.
+** NATURAL joins also create extra WHERE clause terms.
+**
+** The terms of a FROM clause are contained in the Select.pSrc structure.
+** The left most table is the first entry in Select.pSrc.  The right-most
+** table is the last entry.  The join operator is held in the entry to
+** the left.  Thus entry 0 contains the join operator for the join between
+** entries 0 and 1.  Any ON or USING clauses associated with the join are
+** also attached to the left entry.
+**
+** This routine returns the number of errors encountered.
+*/
+static int sqliteProcessJoin(Parse *pParse, Select *p){
+  SrcList *pSrc;                  /* All tables in the FROM clause */
+  int i, j;                       /* Loop counters */
+  struct SrcList_item *pLeft;     /* Left table being joined */
+  struct SrcList_item *pRight;    /* Right table being joined */
+
+  pSrc = p->pSrc;
+  pLeft = &pSrc->a[0];
+  pRight = &pLeft[1];
+  for(i=0; i<pSrc->nSrc-1; i++, pRight++, pLeft++){
+    Table *pLeftTab = pLeft->pTab;
+    Table *pRightTab = pRight->pTab;
+    int isOuter;
+
+    if( pLeftTab==0 || pRightTab==0 ) continue;
+    isOuter = (pRight->jointype & JT_OUTER)!=0;
+
+    /* When the NATURAL keyword is present, add WHERE clause terms for
+    ** every column that the two tables have in common.
+    */
+    if( pRight->jointype & JT_NATURAL ){
+      if( pRight->pOn || pRight->pUsing ){
+        sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
+           "an ON or USING clause", 0);
+        return 1;
+      }
+      for(j=0; j<pLeftTab->nCol; j++){
+        char *zName = pLeftTab->aCol[j].zName;
+        if( columnIndex(pRightTab, zName)>=0 ){
+          addWhereTerm(pParse, zName, pLeftTab, pLeft->zAlias, 
+                              pRightTab, pRight->zAlias,
+                              pRight->iCursor, &p->pWhere, isOuter);
+          
+        }
+      }
+    }
+
+    /* Disallow both ON and USING clauses in the same join
+    */
+    if( pRight->pOn && pRight->pUsing ){
+      sqlite3ErrorMsg(pParse, "cannot have both ON and USING "
+        "clauses in the same join");
+      return 1;
+    }
+
+    /* Add the ON clause to the end of the WHERE clause, connected by
+    ** an AND operator.
+    */
+    if( pRight->pOn ){
+      if( isOuter ) setJoinExpr(pRight->pOn, pRight->iCursor);
+      p->pWhere = sqlite3ExprAnd(pParse->db, p->pWhere, pRight->pOn);
+      pRight->pOn = 0;
+    }
+
+    /* Create extra terms on the WHERE clause for each column named
+    ** in the USING clause.  Example: If the two tables to be joined are 
+    ** A and B and the USING clause names X, Y, and Z, then add this
+    ** to the WHERE clause:    A.X=B.X AND A.Y=B.Y AND A.Z=B.Z
+    ** Report an error if any column mentioned in the USING clause is
+    ** not contained in both tables to be joined.
+    */
+    if( pRight->pUsing ){
+      IdList *pList = pRight->pUsing;
+      for(j=0; j<pList->nId; j++){
+        char *zName = pList->a[j].zName;
+        if( columnIndex(pLeftTab, zName)<0 || columnIndex(pRightTab, zName)<0 ){
+          sqlite3ErrorMsg(pParse, "cannot join using column %s - column "
+            "not present in both tables", zName);
+          return 1;
+        }
+        addWhereTerm(pParse, zName, pLeftTab, pLeft->zAlias, 
+                            pRightTab, pRight->zAlias,
+                            pRight->iCursor, &p->pWhere, isOuter);
+      }
+    }
+  }
+  return 0;
+}
+
+/*
+** Insert code into "v" that will push the record on the top of the
+** stack into the sorter.
+*/
+static void pushOntoSorter(
+  Parse *pParse,         /* Parser context */
+  ExprList *pOrderBy,    /* The ORDER BY clause */
+  Select *pSelect,       /* The whole SELECT statement */
+  int regData            /* Register holding data to be sorted */
+){
+  Vdbe *v = pParse->pVdbe;
+  int nExpr = pOrderBy->nExpr;
+  int regBase = sqlite3GetTempRange(pParse, nExpr+2);
+  int regRecord = sqlite3GetTempReg(pParse);
+  sqlite3ExprCodeExprList(pParse, pOrderBy, regBase, 0);
+  sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr);
+  sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+1, 1);
+  sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nExpr + 2, regRecord);
+  sqlite3VdbeAddOp2(v, OP_IdxInsert, pOrderBy->iECursor, regRecord);
+  sqlite3ReleaseTempReg(pParse, regRecord);
+  sqlite3ReleaseTempRange(pParse, regBase, nExpr+2);
+  if( pSelect->iLimit ){
+    int addr1, addr2;
+    int iLimit;
+    if( pSelect->iOffset ){
+      iLimit = pSelect->iOffset+1;
+    }else{
+      iLimit = pSelect->iLimit;
+    }
+    addr1 = sqlite3VdbeAddOp1(v, OP_IfZero, iLimit);
+    sqlite3VdbeAddOp2(v, OP_AddImm, iLimit, -1);
+    addr2 = sqlite3VdbeAddOp0(v, OP_Goto);
+    sqlite3VdbeJumpHere(v, addr1);
+    sqlite3VdbeAddOp1(v, OP_Last, pOrderBy->iECursor);
+    sqlite3VdbeAddOp1(v, OP_Delete, pOrderBy->iECursor);
+    sqlite3VdbeJumpHere(v, addr2);
+    pSelect->iLimit = 0;
+  }
+}
+
+/*
+** Add code to implement the OFFSET
+*/
+static void codeOffset(
+  Vdbe *v,          /* Generate code into this VM */
+  Select *p,        /* The SELECT statement being coded */
+  int iContinue     /* Jump here to skip the current record */
+){
+  if( p->iOffset && iContinue!=0 ){
+    int addr;
+    sqlite3VdbeAddOp2(v, OP_AddImm, p->iOffset, -1);
+    addr = sqlite3VdbeAddOp1(v, OP_IfNeg, p->iOffset);
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, iContinue);
+    VdbeComment((v, "skip OFFSET records"));
+    sqlite3VdbeJumpHere(v, addr);
+  }
+}
+
+/*
+** Add code that will check to make sure the N registers starting at iMem
+** form a distinct entry.  iTab is a sorting index that holds previously
+** seen combinations of the N values.  A new entry is made in iTab
+** if the current N values are new.
+**
+** A jump to addrRepeat is made and the N+1 values are popped from the
+** stack if the top N elements are not distinct.
+*/
+static void codeDistinct(
+  Parse *pParse,     /* Parsing and code generating context */
+  int iTab,          /* A sorting index used to test for distinctness */
+  int addrRepeat,    /* Jump to here if not distinct */
+  int N,             /* Number of elements */
+  int iMem           /* First element */
+){
+  Vdbe *v;
+  int r1;
+
+  v = pParse->pVdbe;
+  r1 = sqlite3GetTempReg(pParse);
+  sqlite3VdbeAddOp3(v, OP_MakeRecord, iMem, N, r1);
+  sqlite3VdbeAddOp3(v, OP_Found, iTab, addrRepeat, r1);
+  sqlite3VdbeAddOp2(v, OP_IdxInsert, iTab, r1);
+  sqlite3ReleaseTempReg(pParse, r1);
+}
+
+/*
+** Generate an error message when a SELECT is used within a subexpression
+** (example:  "a IN (SELECT * FROM table)") but it has more than 1 result
+** column.  We do this in a subroutine because the error occurs in multiple
+** places.
+*/
+static int checkForMultiColumnSelectError(
+  Parse *pParse,       /* Parse context. */
+  SelectDest *pDest,   /* Destination of SELECT results */
+  int nExpr            /* Number of result columns returned by SELECT */
+){
+  int eDest = pDest->eDest;
+  if( nExpr>1 && (eDest==SRT_Mem || eDest==SRT_Set) ){
+    sqlite3ErrorMsg(pParse, "only a single result allowed for "
+       "a SELECT that is part of an expression");
+    return 1;
+  }else{
+    return 0;
+  }
+}
+
+/*
+** This routine generates the code for the inside of the inner loop
+** of a SELECT.
+**
+** If srcTab and nColumn are both zero, then the pEList expressions
+** are evaluated in order to get the data for this row.  If nColumn>0
+** then data is pulled from srcTab and pEList is used only to get the
+** datatypes for each column.
+*/
+static void selectInnerLoop(
+  Parse *pParse,          /* The parser context */
+  Select *p,              /* The complete select statement being coded */
+  ExprList *pEList,       /* List of values being extracted */
+  int srcTab,             /* Pull data from this table */
+  int nColumn,            /* Number of columns in the source table */
+  ExprList *pOrderBy,     /* If not NULL, sort results using this key */
+  int distinct,           /* If >=0, make sure results are distinct */
+  SelectDest *pDest,      /* How to dispose of the results */
+  int iContinue,          /* Jump here to continue with next row */
+  int iBreak              /* Jump here to break out of the inner loop */
+){
+  Vdbe *v = pParse->pVdbe;
+  int i;
+  int hasDistinct;        /* True if the DISTINCT keyword is present */
+  int regResult;              /* Start of memory holding result set */
+  int eDest = pDest->eDest;   /* How to dispose of results */
+  int iParm = pDest->iParm;   /* First argument to disposal method */
+  int nResultCol;             /* Number of result columns */
+
+  if( v==0 ) return;
+  assert( pEList!=0 );
+  hasDistinct = distinct>=0;
+  if( pOrderBy==0 && !hasDistinct ){
+    codeOffset(v, p, iContinue);
+  }
+
+  /* Pull the requested columns.
+  */
+  if( nColumn>0 ){
+    nResultCol = nColumn;
+  }else{
+    nResultCol = pEList->nExpr;
+  }
+  if( pDest->iMem==0 ){
+    pDest->iMem = pParse->nMem+1;
+    pDest->nMem = nResultCol;
+    pParse->nMem += nResultCol;
+  }else if( pDest->nMem!=nResultCol ){
+    /* This happens when two SELECTs of a compound SELECT have differing
+    ** numbers of result columns.  The error message will be generated by
+    ** a higher-level routine. */
+    return;
+  }
+  regResult = pDest->iMem;
+  if( nColumn>0 ){
+    for(i=0; i<nColumn; i++){
+      sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i);
+    }
+  }else if( eDest!=SRT_Exists ){
+    /* If the destination is an EXISTS(...) expression, the actual
+    ** values returned by the SELECT are not required.
+    */
+    sqlite3ExprCodeExprList(pParse, pEList, regResult, eDest==SRT_Callback);
+  }
+  nColumn = nResultCol;
+
+  /* If the DISTINCT keyword was present on the SELECT statement
+  ** and this row has been seen before, then do not make this row
+  ** part of the result.
+  */
+  if( hasDistinct ){
+    assert( pEList!=0 );
+    assert( pEList->nExpr==nColumn );
+    codeDistinct(pParse, distinct, iContinue, nColumn, regResult);
+    if( pOrderBy==0 ){
+      codeOffset(v, p, iContinue);
+    }
+  }
+
+  if( checkForMultiColumnSelectError(pParse, pDest, pEList->nExpr) ){
+    return;
+  }
+
+  switch( eDest ){
+    /* In this mode, write each query result to the key of the temporary
+    ** table iParm.
+    */
+#ifndef SQLITE_OMIT_COMPOUND_SELECT
+    case SRT_Union: {
+      int r1;
+      r1 = sqlite3GetTempReg(pParse);
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
+      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
+      sqlite3ReleaseTempReg(pParse, r1);
+      break;
+    }
+
+    /* Construct a record from the query result, but instead of
+    ** saving that record, use it as a key to delete elements from
+    ** the temporary table iParm.
+    */
+    case SRT_Except: {
+      sqlite3VdbeAddOp3(v, OP_IdxDelete, iParm, regResult, nColumn);
+      break;
+    }
+#endif
+
+    /* Store the result as data using a unique key.
+    */
+    case SRT_Table:
+    case SRT_EphemTab: {
+      int r1 = sqlite3GetTempReg(pParse);
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
+      if( pOrderBy ){
+        pushOntoSorter(pParse, pOrderBy, p, r1);
+      }else{
+        int r2 = sqlite3GetTempReg(pParse);
+        sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);
+        sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, r2);
+        sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
+        sqlite3ReleaseTempReg(pParse, r2);
+      }
+      sqlite3ReleaseTempReg(pParse, r1);
+      break;
+    }
+
+#ifndef SQLITE_OMIT_SUBQUERY
+    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
+    ** then there should be a single item on the stack.  Write this
+    ** item into the set table with bogus data.
+    */
+    case SRT_Set: {
+      assert( nColumn==1 );
+      p->affinity = sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affinity);
+      if( pOrderBy ){
+        /* At first glance you would think we could optimize out the
+        ** ORDER BY in this case since the order of entries in the set
+        ** does not matter.  But there might be a LIMIT clause, in which
+        ** case the order does matter */
+        pushOntoSorter(pParse, pOrderBy, p, regResult);
+      }else{
+        int r1 = sqlite3GetTempReg(pParse);
+        sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult, 1, r1, &p->affinity, 1);
+        sqlite3ExprCacheAffinityChange(pParse, regResult, 1);
+        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
+        sqlite3ReleaseTempReg(pParse, r1);
+      }
+      break;
+    }
+
+    /* If any row exist in the result set, record that fact and abort.
+    */
+    case SRT_Exists: {
+      sqlite3VdbeAddOp2(v, OP_Integer, 1, iParm);
+      /* The LIMIT clause will terminate the loop for us */
+      break;
+    }
+
+    /* If this is a scalar select that is part of an expression, then
+    ** store the results in the appropriate memory cell and break out
+    ** of the scan loop.
+    */
+    case SRT_Mem: {
+      assert( nColumn==1 );
+      if( pOrderBy ){
+        pushOntoSorter(pParse, pOrderBy, p, regResult);
+      }else{
+        sqlite3ExprCodeMove(pParse, regResult, iParm, 1);
+        /* The LIMIT clause will jump out of the loop for us */
+      }
+      break;
+    }
+#endif /* #ifndef SQLITE_OMIT_SUBQUERY */
+
+    /* Send the data to the callback function or to a subroutine.  In the
+    ** case of a subroutine, the subroutine itself is responsible for
+    ** popping the data from the stack.
+    */
+    case SRT_Coroutine:
+    case SRT_Callback: {
+      if( pOrderBy ){
+        int r1 = sqlite3GetTempReg(pParse);
+        sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
+        pushOntoSorter(pParse, pOrderBy, p, r1);
+        sqlite3ReleaseTempReg(pParse, r1);
+      }else if( eDest==SRT_Coroutine ){
+        sqlite3VdbeAddOp1(v, OP_Yield, pDest->iParm);
+      }else{
+        sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nColumn);
+        sqlite3ExprCacheAffinityChange(pParse, regResult, nColumn);
+      }
+      break;
+    }
+
+#if !defined(SQLITE_OMIT_TRIGGER)
+    /* Discard the results.  This is used for SELECT statements inside
+    ** the body of a TRIGGER.  The purpose of such selects is to call
+    ** user-defined functions that have side effects.  We do not care
+    ** about the actual results of the select.
+    */
+    default: {
+      assert( eDest==SRT_Discard );
+      break;
+    }
+#endif
+  }
+
+  /* Jump to the end of the loop if the LIMIT is reached.
+  */
+  if( p->iLimit ){
+    assert( pOrderBy==0 );  /* If there is an ORDER BY, the call to
+                            ** pushOntoSorter() would have cleared p->iLimit */
+    sqlite3VdbeAddOp2(v, OP_AddImm, p->iLimit, -1);
+    sqlite3VdbeAddOp2(v, OP_IfZero, p->iLimit, iBreak);
+  }
+}
+
+/*
+** Given an expression list, generate a KeyInfo structure that records
+** the collating sequence for each expression in that expression list.
+**
+** If the ExprList is an ORDER BY or GROUP BY clause then the resulting
+** KeyInfo structure is appropriate for initializing a virtual index to
+** implement that clause.  If the ExprList is the result set of a SELECT
+** then the KeyInfo structure is appropriate for initializing a virtual
+** index to implement a DISTINCT test.
+**
+** Space to hold the KeyInfo structure is obtain from malloc.  The calling
+** function is responsible for seeing that this structure is eventually
+** freed.  Add the KeyInfo structure to the P4 field of an opcode using
+** P4_KEYINFO_HANDOFF is the usual way of dealing with this.
+*/
+static KeyInfo *keyInfoFromExprList(Parse *pParse, ExprList *pList){
+  sqlite3 *db = pParse->db;
+  int nExpr;
+  KeyInfo *pInfo;
+  struct ExprList_item *pItem;
+  int i;
+
+  nExpr = pList->nExpr;
+  pInfo = sqlite3DbMallocZero(db, sizeof(*pInfo) + nExpr*(sizeof(CollSeq*)+1) );
+  if( pInfo ){
+    pInfo->aSortOrder = (u8*)&pInfo->aColl[nExpr];
+    pInfo->nField = nExpr;
+    pInfo->enc = ENC(db);
+    for(i=0, pItem=pList->a; i<nExpr; i++, pItem++){
+      CollSeq *pColl;
+      pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
+      if( !pColl ){
+        pColl = db->pDfltColl;
+      }
+      pInfo->aColl[i] = pColl;
+      pInfo->aSortOrder[i] = pItem->sortOrder;
+    }
+  }
+  return pInfo;
+}
+
+
+/*
+** If the inner loop was generated using a non-null pOrderBy argument,
+** then the results were placed in a sorter.  After the loop is terminated
+** we need to run the sorter and output the results.  The following
+** routine generates the code needed to do that.
+*/
+static void generateSortTail(
+  Parse *pParse,    /* Parsing context */
+  Select *p,        /* The SELECT statement */
+  Vdbe *v,          /* Generate code into this VDBE */
+  int nColumn,      /* Number of columns of data */
+  SelectDest *pDest /* Write the sorted results here */
+){
+  int brk = sqlite3VdbeMakeLabel(v);
+  int cont = sqlite3VdbeMakeLabel(v);
+  int addr;
+  int iTab;
+  int pseudoTab = 0;
+  ExprList *pOrderBy = p->pOrderBy;
+
+  int eDest = pDest->eDest;
+  int iParm = pDest->iParm;
+
+  int regRow;
+  int regRowid;
+
+  iTab = pOrderBy->iECursor;
+  if( eDest==SRT_Callback || eDest==SRT_Coroutine ){
+    pseudoTab = pParse->nTab++;
+    sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, nColumn);
+    sqlite3VdbeAddOp2(v, OP_OpenPseudo, pseudoTab, eDest==SRT_Callback);
+  }
+  addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, brk);
+  codeOffset(v, p, cont);
+  regRow = sqlite3GetTempReg(pParse);
+  regRowid = sqlite3GetTempReg(pParse);
+  sqlite3VdbeAddOp3(v, OP_Column, iTab, pOrderBy->nExpr + 1, regRow);
+  switch( eDest ){
+    case SRT_Table:
+    case SRT_EphemTab: {
+      sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);
+      sqlite3VdbeAddOp3(v, OP_Insert, iParm, regRow, regRowid);
+      sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
+      break;
+    }
+#ifndef SQLITE_OMIT_SUBQUERY
+    case SRT_Set: {
+      assert( nColumn==1 );
+      sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, 1, regRowid, &p->affinity, 1);
+      sqlite3ExprCacheAffinityChange(pParse, regRow, 1);
+      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, regRowid);
+      break;
+    }
+    case SRT_Mem: {
+      assert( nColumn==1 );
+      sqlite3ExprCodeMove(pParse, regRow, iParm, 1);
+      /* The LIMIT clause will terminate the loop for us */
+      break;
+    }
+#endif
+    case SRT_Callback:
+    case SRT_Coroutine: {
+      int i;
+      sqlite3VdbeAddOp2(v, OP_Integer, 1, regRowid);
+      sqlite3VdbeAddOp3(v, OP_Insert, pseudoTab, regRow, regRowid);
+      for(i=0; i<nColumn; i++){
+        assert( regRow!=pDest->iMem+i );
+        sqlite3VdbeAddOp3(v, OP_Column, pseudoTab, i, pDest->iMem+i);
+      }
+      if( eDest==SRT_Callback ){
+        sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iMem, nColumn);
+        sqlite3ExprCacheAffinityChange(pParse, pDest->iMem, nColumn);
+      }else{
+        sqlite3VdbeAddOp1(v, OP_Yield, pDest->iParm);
+      }
+      break;
+    }
+    default: {
+      /* Do nothing */
+      break;
+    }
+  }
+  sqlite3ReleaseTempReg(pParse, regRow);
+  sqlite3ReleaseTempReg(pParse, regRowid);
+
+  /* LIMIT has been implemented by the pushOntoSorter() routine.
+  */
+  assert( p->iLimit==0 );
+
+  /* The bottom of the loop
+  */
+  sqlite3VdbeResolveLabel(v, cont);
+  sqlite3VdbeAddOp2(v, OP_Next, iTab, addr);
+  sqlite3VdbeResolveLabel(v, brk);
+  if( eDest==SRT_Callback || eDest==SRT_Coroutine ){
+    sqlite3VdbeAddOp2(v, OP_Close, pseudoTab, 0);
+  }
+
+}
+
+/*
+** Return a pointer to a string containing the 'declaration type' of the
+** expression pExpr. The string may be treated as static by the caller.
+**
+** The declaration type is the exact datatype definition extracted from the
+** original CREATE TABLE statement if the expression is a column. The
+** declaration type for a ROWID field is INTEGER. Exactly when an expression
+** is considered a column can be complex in the presence of subqueries. The
+** result-set expression in all of the following SELECT statements is 
+** considered a column by this function.
+**
+**   SELECT col FROM tbl;
+**   SELECT (SELECT col FROM tbl;
+**   SELECT (SELECT col FROM tbl);
+**   SELECT abc FROM (SELECT col AS abc FROM tbl);
+** 
+** The declaration type for any expression other than a column is NULL.
+*/
+static const char *columnType(
+  NameContext *pNC, 
+  Expr *pExpr,
+  const char **pzOriginDb,
+  const char **pzOriginTab,
+  const char **pzOriginCol
+){
+  char const *zType = 0;
+  char const *zOriginDb = 0;
+  char const *zOriginTab = 0;
+  char const *zOriginCol = 0;
+  int j;
+  if( pExpr==0 || pNC->pSrcList==0 ) return 0;
+
+  switch( pExpr->op ){
+    case TK_AGG_COLUMN:
+    case TK_COLUMN: {
+      /* The expression is a column. Locate the table the column is being
+      ** extracted from in NameContext.pSrcList. This table may be real
+      ** database table or a subquery.
+      */
+      Table *pTab = 0;            /* Table structure column is extracted from */
+      Select *pS = 0;             /* Select the column is extracted from */
+      int iCol = pExpr->iColumn;  /* Index of column in pTab */
+      while( pNC && !pTab ){
+        SrcList *pTabList = pNC->pSrcList;
+        for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);
+        if( j<pTabList->nSrc ){
+          pTab = pTabList->a[j].pTab;
+          pS = pTabList->a[j].pSelect;
+        }else{
+          pNC = pNC->pNext;
+        }
+      }
+
+      if( pTab==0 ){
+        /* FIX ME:
+        ** This can occurs if you have something like "SELECT new.x;" inside
+        ** a trigger.  In other words, if you reference the special "new"
+        ** table in the result set of a select.  We do not have a good way
+        ** to find the actual table type, so call it "TEXT".  This is really
+        ** something of a bug, but I do not know how to fix it.
+        **
+        ** This code does not produce the correct answer - it just prevents
+        ** a segfault.  See ticket #1229.
+        */
+        zType = "TEXT";
+        break;
+      }
+
+      assert( pTab );
+      if( pS ){
+        /* The "table" is actually a sub-select or a view in the FROM clause
+        ** of the SELECT statement. Return the declaration type and origin
+        ** data for the result-set column of the sub-select.
+        */
+        if( iCol>=0 && iCol<pS->pEList->nExpr ){
+          /* If iCol is less than zero, then the expression requests the
+          ** rowid of the sub-select or view. This expression is legal (see 
+          ** test case misc2.2.2) - it always evaluates to NULL.
+          */
+          NameContext sNC;
+          Expr *p = pS->pEList->a[iCol].pExpr;
+          sNC.pSrcList = pS->pSrc;
+          sNC.pNext = 0;
+          sNC.pParse = pNC->pParse;
+          zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol); 
+        }
+      }else if( pTab->pSchema ){
+        /* A real table */
+        assert( !pS );
+        if( iCol<0 ) iCol = pTab->iPKey;
+        assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
+        if( iCol<0 ){
+          zType = "INTEGER";
+          zOriginCol = "rowid";
+        }else{
+          zType = pTab->aCol[iCol].zType;
+          zOriginCol = pTab->aCol[iCol].zName;
+        }
+        zOriginTab = pTab->zName;
+        if( pNC->pParse ){
+          int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema);
+          zOriginDb = pNC->pParse->db->aDb[iDb].zName;
+        }
+      }
+      break;
+    }
+#ifndef SQLITE_OMIT_SUBQUERY
+    case TK_SELECT: {
+      /* The expression is a sub-select. Return the declaration type and
+      ** origin info for the single column in the result set of the SELECT
+      ** statement.
+      */
+      NameContext sNC;
+      Select *pS = pExpr->pSelect;
+      Expr *p = pS->pEList->a[0].pExpr;
+      sNC.pSrcList = pS->pSrc;
+      sNC.pNext = pNC;
+      sNC.pParse = pNC->pParse;
+      zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol); 
+      break;
+    }
+#endif
+  }
+  
+  if( pzOriginDb ){
+    assert( pzOriginTab && pzOriginCol );
+    *pzOriginDb = zOriginDb;
+    *pzOriginTab = zOriginTab;
+    *pzOriginCol = zOriginCol;
+  }
+  return zType;
+}
+
+/*
+** Generate code that will tell the VDBE the declaration types of columns
+** in the result set.
+*/
+static void generateColumnTypes(
+  Parse *pParse,      /* Parser context */
+  SrcList *pTabList,  /* List of tables */
+  ExprList *pEList    /* Expressions defining the result set */
+){
+#ifndef SQLITE_OMIT_DECLTYPE
+  Vdbe *v = pParse->pVdbe;
+  int i;
+  NameContext sNC;
+  sNC.pSrcList = pTabList;
+  sNC.pParse = pParse;
+  for(i=0; i<pEList->nExpr; i++){
+    Expr *p = pEList->a[i].pExpr;
+    const char *zType;
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+    const char *zOrigDb = 0;
+    const char *zOrigTab = 0;
+    const char *zOrigCol = 0;
+    zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);
+
+    /* The vdbe must make its own copy of the column-type and other 
+    ** column specific strings, in case the schema is reset before this
+    ** virtual machine is deleted.
+    */
+    sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, P4_TRANSIENT);
+    sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, P4_TRANSIENT);
+    sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, P4_TRANSIENT);
+#else
+    zType = columnType(&sNC, p, 0, 0, 0);
+#endif
+    sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, P4_TRANSIENT);
+  }
+#endif /* SQLITE_OMIT_DECLTYPE */
+}
+
+/*
+** Generate code that will tell the VDBE the names of columns
+** in the result set.  This information is used to provide the
+** azCol[] values in the callback.
+*/
+static void generateColumnNames(
+  Parse *pParse,      /* Parser context */
+  SrcList *pTabList,  /* List of tables */
+  ExprList *pEList    /* Expressions defining the result set */
+){
+  Vdbe *v = pParse->pVdbe;
+  int i, j;
+  sqlite3 *db = pParse->db;
+  int fullNames, shortNames;
+
+#ifndef SQLITE_OMIT_EXPLAIN
+  /* If this is an EXPLAIN, skip this step */
+  if( pParse->explain ){
+    return;
+  }
+#endif
+
+  assert( v!=0 );
+  if( pParse->colNamesSet || v==0 || db->mallocFailed ) return;
+  pParse->colNamesSet = 1;
+  fullNames = (db->flags & SQLITE_FullColNames)!=0;
+  shortNames = (db->flags & SQLITE_ShortColNames)!=0;
+  sqlite3VdbeSetNumCols(v, pEList->nExpr);
+  for(i=0; i<pEList->nExpr; i++){
+    Expr *p;
+    p = pEList->a[i].pExpr;
+    if( p==0 ) continue;
+    if( pEList->a[i].zName ){
+      char *zName = pEList->a[i].zName;
+      sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, strlen(zName));
+    }else if( p->op==TK_COLUMN && pTabList ){
+      Table *pTab;
+      char *zCol;
+      int iCol = p->iColumn;
+      for(j=0; j<pTabList->nSrc && pTabList->a[j].iCursor!=p->iTable; j++){}
+      assert( j<pTabList->nSrc );
+      pTab = pTabList->a[j].pTab;
+      if( iCol<0 ) iCol = pTab->iPKey;
+      assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
+      if( iCol<0 ){
+        zCol = "rowid";
+      }else{
+        zCol = pTab->aCol[iCol].zName;
+      }
+      if( !shortNames && !fullNames ){
+        sqlite3VdbeSetColName(v, i, COLNAME_NAME, (char*)p->span.z, p->span.n);
+      }else if( fullNames || (!shortNames && pTabList->nSrc>1) ){
+        char *zName = 0;
+        char *zTab;
+ 
+        zTab = pTabList->a[j].zAlias;
+        if( fullNames || zTab==0 ) zTab = pTab->zName;
+        zName = sqlite3MPrintf(db, "%s.%s", zTab, zCol);
+        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, P4_DYNAMIC);
+      }else{
+        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, strlen(zCol));
+      }
+    }else{
+      sqlite3VdbeSetColName(v, i, COLNAME_NAME, (char*)p->span.z, p->span.n);
+    }
+  }
+  generateColumnTypes(pParse, pTabList, pEList);
+}
+
+#ifndef SQLITE_OMIT_COMPOUND_SELECT
+/*
+** Name of the connection operator, used for error messages.
+*/
+static const char *selectOpName(int id){
+  char *z;
+  switch( id ){
+    case TK_ALL:       z = "UNION ALL";   break;
+    case TK_INTERSECT: z = "INTERSECT";   break;
+    case TK_EXCEPT:    z = "EXCEPT";      break;
+    default:           z = "UNION";       break;
+  }
+  return z;
+}
+#endif /* SQLITE_OMIT_COMPOUND_SELECT */
+
+/*
+** Forward declaration
+*/
+static int prepSelectStmt(Parse*, Select*);
+
+/*
+** Given a SELECT statement, generate a Table structure that describes
+** the result set of that SELECT.
+*/
+Table *sqlite3ResultSetOfSelect(Parse *pParse, char *zTabName, Select *pSelect){
+  Table *pTab;
+  int i, j, rc;
+  ExprList *pEList;
+  Column *aCol, *pCol;
+  sqlite3 *db = pParse->db;
+  int savedFlags;
+
+  savedFlags = db->flags;
+  db->flags &= ~SQLITE_FullColNames;
+  db->flags |= SQLITE_ShortColNames;
+  rc = sqlite3SelectResolve(pParse, pSelect, 0);
+  if( rc==SQLITE_OK ){
+    while( pSelect->pPrior ) pSelect = pSelect->pPrior;
+    rc = prepSelectStmt(pParse, pSelect);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3SelectResolve(pParse, pSelect, 0);
+    }
+  }
+  db->flags = savedFlags;
+  if( rc ){
+    return 0;
+  }
+  pTab = sqlite3DbMallocZero(db, sizeof(Table) );
+  if( pTab==0 ){
+    return 0;
+  }
+  pTab->db = db;
+  pTab->nRef = 1;
+  pTab->zName = zTabName ? sqlite3DbStrDup(db, zTabName) : 0;
+  pEList = pSelect->pEList;
+  pTab->nCol = pEList->nExpr;
+  assert( pTab->nCol>0 );
+  pTab->aCol = aCol = sqlite3DbMallocZero(db, sizeof(pTab->aCol[0])*pTab->nCol);
+  testcase( aCol==0 );
+  for(i=0, pCol=aCol; i<pTab->nCol; i++, pCol++){
+    Expr *p;
+    char *zType;
+    char *zName;
+    int nName;
+    CollSeq *pColl;
+    int cnt;
+    NameContext sNC;
+    
+    /* Get an appropriate name for the column
+    */
+    p = pEList->a[i].pExpr;
+    assert( p->pRight==0 || p->pRight->token.z==0 || p->pRight->token.z[0]!=0 );
+    if( (zName = pEList->a[i].zName)!=0 ){
+      /* If the column contains an "AS <name>" phrase, use <name> as the name */
+      zName = sqlite3DbStrDup(db, zName);
+    }else if( p->op==TK_COLUMN && p->pTab ){
+      /* For columns use the column name name */
+      int iCol = p->iColumn;
+      if( iCol<0 ) iCol = p->pTab->iPKey;
+      zName = sqlite3MPrintf(db, "%s", p->pTab->aCol[iCol].zName);
+    }else{
+      /* Use the original text of the column expression as its name */
+      zName = sqlite3MPrintf(db, "%T", &p->span);
+    }
+    if( db->mallocFailed ){
+      sqlite3DbFree(db, zName);
+      break;
+    }
+    sqlite3Dequote(zName);
+
+    /* Make sure the column name is unique.  If the name is not unique,
+    ** append a integer to the name so that it becomes unique.
+    */
+    nName = strlen(zName);
+    for(j=cnt=0; j<i; j++){
+      if( sqlite3StrICmp(aCol[j].zName, zName)==0 ){
+        char *zNewName;
+        zName[nName] = 0;
+        zNewName = sqlite3MPrintf(db, "%s:%d", zName, ++cnt);
+        sqlite3DbFree(db, zName);
+        zName = zNewName;
+        j = -1;
+        if( zName==0 ) break;
+      }
+    }
+    pCol->zName = zName;
+
+    /* Get the typename, type affinity, and collating sequence for the
+    ** column.
+    */
+    memset(&sNC, 0, sizeof(sNC));
+    sNC.pSrcList = pSelect->pSrc;
+    zType = sqlite3DbStrDup(db, columnType(&sNC, p, 0, 0, 0));
+    pCol->zType = zType;
+    pCol->affinity = sqlite3ExprAffinity(p);
+    pColl = sqlite3ExprCollSeq(pParse, p);
+    if( pColl ){
+      pCol->zColl = sqlite3DbStrDup(db, pColl->zName);
+    }
+  }
+  pTab->iPKey = -1;
+  if( db->mallocFailed ){
+    sqlite3DeleteTable(pTab);
+    return 0;
+  }
+  return pTab;
+}
+
+/*
+** Prepare a SELECT statement for processing by doing the following
+** things:
+**
+**    (1)  Make sure VDBE cursor numbers have been assigned to every
+**         element of the FROM clause.
+**
+**    (2)  Fill in the pTabList->a[].pTab fields in the SrcList that 
+**         defines FROM clause.  When views appear in the FROM clause,
+**         fill pTabList->a[].pSelect with a copy of the SELECT statement
+**         that implements the view.  A copy is made of the view's SELECT
+**         statement so that we can freely modify or delete that statement
+**         without worrying about messing up the presistent representation
+**         of the view.
+**
+**    (3)  Add terms to the WHERE clause to accomodate the NATURAL keyword
+**         on joins and the ON and USING clause of joins.
+**
+**    (4)  Scan the list of columns in the result set (pEList) looking
+**         for instances of the "*" operator or the TABLE.* operator.
+**         If found, expand each "*" to be every column in every table
+**         and TABLE.* to be every column in TABLE.
+**
+** Return 0 on success.  If there are problems, leave an error message
+** in pParse and return non-zero.
+*/
+static int prepSelectStmt(Parse *pParse, Select *p){
+  int i, j, k, rc;
+  SrcList *pTabList;
+  ExprList *pEList;
+  struct SrcList_item *pFrom;
+  sqlite3 *db = pParse->db;
+
+  if( p==0 || p->pSrc==0 || db->mallocFailed ){
+    return 1;
+  }
+  pTabList = p->pSrc;
+  pEList = p->pEList;
+
+  /* Make sure cursor numbers have been assigned to all entries in
+  ** the FROM clause of the SELECT statement.
+  */
+  sqlite3SrcListAssignCursors(pParse, p->pSrc);
+
+  /* Look up every table named in the FROM clause of the select.  If
+  ** an entry of the FROM clause is a subquery instead of a table or view,
+  ** then create a transient table structure to describe the subquery.
+  */
+  for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
+    Table *pTab;
+    if( pFrom->pTab!=0 ){
+      /* This statement has already been prepared.  There is no need
+      ** to go further. */
+      assert( i==0 );
+      return 0;
+    }
+    if( pFrom->zName==0 ){
+#ifndef SQLITE_OMIT_SUBQUERY
+      /* A sub-query in the FROM clause of a SELECT */
+      assert( pFrom->pSelect!=0 );
+      if( pFrom->zAlias==0 ){
+        pFrom->zAlias =
+          sqlite3MPrintf(db, "sqlite_subquery_%p_", (void*)pFrom->pSelect);
+      }
+      assert( pFrom->pTab==0 );
+      pFrom->pTab = pTab = 
+        sqlite3ResultSetOfSelect(pParse, pFrom->zAlias, pFrom->pSelect);
+      if( pTab==0 ){
+        return 1;
+      }
+      /* The isEphem flag indicates that the Table structure has been
+      ** dynamically allocated and may be freed at any time.  In other words,
+      ** pTab is not pointing to a persistent table structure that defines
+      ** part of the schema. */
+      pTab->isEphem = 1;
+#endif
+    }else{
+      /* An ordinary table or view name in the FROM clause */
+      assert( pFrom->pTab==0 );
+      pFrom->pTab = pTab = 
+        sqlite3LocateTable(pParse,0,pFrom->zName,pFrom->zDatabase);
+      if( pTab==0 ){
+        return 1;
+      }
+      pTab->nRef++;
+#if !defined(SQLITE_OMIT_VIEW) || !defined (SQLITE_OMIT_VIRTUALTABLE)
+      if( pTab->pSelect || IsVirtual(pTab) ){
+        /* We reach here if the named table is a really a view */
+        if( sqlite3ViewGetColumnNames(pParse, pTab) ){
+          return 1;
+        }
+        /* If pFrom->pSelect!=0 it means we are dealing with a
+        ** view within a view.  The SELECT structure has already been
+        ** copied by the outer view so we can skip the copy step here
+        ** in the inner view.
+        */
+        if( pFrom->pSelect==0 ){
+          pFrom->pSelect = sqlite3SelectDup(db, pTab->pSelect);
+        }
+      }
+#endif
+    }
+  }
+
+  /* Process NATURAL keywords, and ON and USING clauses of joins.
+  */
+  if( sqliteProcessJoin(pParse, p) ) return 1;
+
+  /* For every "*" that occurs in the column list, insert the names of
+  ** all columns in all tables.  And for every TABLE.* insert the names
+  ** of all columns in TABLE.  The parser inserted a special expression
+  ** with the TK_ALL operator for each "*" that it found in the column list.
+  ** The following code just has to locate the TK_ALL expressions and expand
+  ** each one to the list of all columns in all tables.
+  **
+  ** The first loop just checks to see if there are any "*" operators
+  ** that need expanding.
+  */
+  for(k=0; k<pEList->nExpr; k++){
+    Expr *pE = pEList->a[k].pExpr;
+    if( pE->op==TK_ALL ) break;
+    if( pE->op==TK_DOT && pE->pRight && pE->pRight->op==TK_ALL
+         && pE->pLeft && pE->pLeft->op==TK_ID ) break;
+  }
+  rc = 0;
+  if( k<pEList->nExpr ){
+    /*
+    ** If we get here it means the result set contains one or more "*"
+    ** operators that need to be expanded.  Loop through each expression
+    ** in the result set and expand them one by one.
+    */
+    struct ExprList_item *a = pEList->a;
+    ExprList *pNew = 0;
+    int flags = pParse->db->flags;
+    int longNames = (flags & SQLITE_FullColNames)!=0
+                      && (flags & SQLITE_ShortColNames)==0;
+
+    for(k=0; k<pEList->nExpr; k++){
+      Expr *pE = a[k].pExpr;
+      if( pE->op!=TK_ALL &&
+           (pE->op!=TK_DOT || pE->pRight==0 || pE->pRight->op!=TK_ALL) ){
+        /* This particular expression does not need to be expanded.
+        */
+        pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr, 0);
+        if( pNew ){
+          pNew->a[pNew->nExpr-1].zName = a[k].zName;
+        }else{
+          rc = 1;
+        }
+        a[k].pExpr = 0;
+        a[k].zName = 0;
+      }else{
+        /* This expression is a "*" or a "TABLE.*" and needs to be
+        ** expanded. */
+        int tableSeen = 0;      /* Set to 1 when TABLE matches */
+        char *zTName;            /* text of name of TABLE */
+        if( pE->op==TK_DOT && pE->pLeft ){
+          zTName = sqlite3NameFromToken(db, &pE->pLeft->token);
+        }else{
+          zTName = 0;
+        }
+        for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
+          Table *pTab = pFrom->pTab;
+          char *zTabName = pFrom->zAlias;
+          if( zTabName==0 || zTabName[0]==0 ){ 
+            zTabName = pTab->zName;
+          }
+          assert( zTabName );
+          if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){
+            continue;
+          }
+          tableSeen = 1;
+          for(j=0; j<pTab->nCol; j++){
+            Expr *pExpr, *pRight;
+            char *zName = pTab->aCol[j].zName;
+
+            /* If a column is marked as 'hidden' (currently only possible
+            ** for virtual tables), do not include it in the expanded
+            ** result-set list.
+            */
+            if( IsHiddenColumn(&pTab->aCol[j]) ){
+              assert(IsVirtual(pTab));
+              continue;
+            }
+
+            if( i>0 ){
+              struct SrcList_item *pLeft = &pTabList->a[i-1];
+              if( (pLeft[1].jointype & JT_NATURAL)!=0 &&
+                        columnIndex(pLeft->pTab, zName)>=0 ){
+                /* In a NATURAL join, omit the join columns from the 
+                ** table on the right */
+                continue;
+              }
+              if( sqlite3IdListIndex(pLeft[1].pUsing, zName)>=0 ){
+                /* In a join with a USING clause, omit columns in the
+                ** using clause from the table on the right. */
+                continue;
+              }
+            }
+            pRight = sqlite3PExpr(pParse, TK_ID, 0, 0, 0);
+            if( pRight==0 ) break;
+            setQuotedToken(pParse, &pRight->token, zName);
+            if( longNames || pTabList->nSrc>1 ){
+              Expr *pLeft = sqlite3PExpr(pParse, TK_ID, 0, 0, 0);
+              pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
+              if( pExpr==0 ) break;
+              setQuotedToken(pParse, &pLeft->token, zTabName);
+#if 1
+              setToken(&pExpr->span, 
+                  sqlite3MPrintf(db, "%s.%s", zTabName, zName));
+              pExpr->span.dyn = 1;
+#else
+              pExpr->span = pRight->token;
+              pExpr->span.dyn = 0;
+#endif
+              pExpr->token.z = 0;
+              pExpr->token.n = 0;
+              pExpr->token.dyn = 0;
+            }else{
+              pExpr = pRight;
+              pExpr->span = pExpr->token;
+              pExpr->span.dyn = 0;
+            }
+            if( longNames ){
+              pNew = sqlite3ExprListAppend(pParse, pNew, pExpr, &pExpr->span);
+            }else{
+              pNew = sqlite3ExprListAppend(pParse, pNew, pExpr, &pRight->token);
+            }
+          }
+        }
+        if( !tableSeen ){
+          if( zTName ){
+            sqlite3ErrorMsg(pParse, "no such table: %s", zTName);
+          }else{
+            sqlite3ErrorMsg(pParse, "no tables specified");
+          }
+          rc = 1;
+        }
+        sqlite3DbFree(db, zTName);
+      }
+    }
+    sqlite3ExprListDelete(db, pEList);
+    p->pEList = pNew;
+  }
+#if SQLITE_MAX_COLUMN
+  if( p->pEList && p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
+    sqlite3ErrorMsg(pParse, "too many columns in result set");
+    rc = SQLITE_ERROR;
+  }
+#endif
+  if( db->mallocFailed ){
+    rc = SQLITE_NOMEM;
+  }
+  return rc;
+}
+
+/*
+** pE is a pointer to an expression which is a single term in
+** ORDER BY or GROUP BY clause.
+**
+** At the point this routine is called, we already know that the
+** ORDER BY term is not an integer index into the result set.  That
+** casee is handled by the calling routine.
+**
+** If pE is a well-formed expression and the SELECT statement
+** is not compound, then return 0.  This indicates to the
+** caller that it should sort by the value of the ORDER BY
+** expression.
+**
+** If the SELECT is compound, then attempt to match pE against
+** result set columns in the left-most SELECT statement.  Return
+** the index i of the matching column, as an indication to the 
+** caller that it should sort by the i-th column.  If there is
+** no match, return -1 and leave an error message in pParse.
+*/
+static int matchOrderByTermToExprList(
+  Parse *pParse,     /* Parsing context for error messages */
+  Select *pSelect,   /* The SELECT statement with the ORDER BY clause */
+  Expr *pE,          /* The specific ORDER BY term */
+  int idx,           /* When ORDER BY term is this */
+  int isCompound,    /* True if this is a compound SELECT */
+  u8 *pHasAgg        /* True if expression contains aggregate functions */
+){
+  int i;             /* Loop counter */
+  ExprList *pEList;  /* The columns of the result set */
+  NameContext nc;    /* Name context for resolving pE */
+
+  assert( sqlite3ExprIsInteger(pE, &i)==0 );
+  pEList = pSelect->pEList;
+
+  /* If the term is a simple identifier that try to match that identifier
+  ** against a column name in the result set.
+  */
+  if( pE->op==TK_ID || (pE->op==TK_STRING && pE->token.z[0]!='\'') ){
+    sqlite3 *db = pParse->db;
+    char *zCol = sqlite3NameFromToken(db, &pE->token);
+    if( zCol==0 ){
+      return -1;
+    }
+    for(i=0; i<pEList->nExpr; i++){
+      char *zAs = pEList->a[i].zName;
+      if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
+        sqlite3DbFree(db, zCol);
+        return i+1;
+      }
+    }
+    sqlite3DbFree(db, zCol);
+  }
+
+  /* Resolve all names in the ORDER BY term expression
+  */
+  memset(&nc, 0, sizeof(nc));
+  nc.pParse = pParse;
+  nc.pSrcList = pSelect->pSrc;
+  nc.pEList = pEList;
+  nc.allowAgg = 1;
+  nc.nErr = 0;
+  if( sqlite3ExprResolveNames(&nc, pE) ){
+    if( isCompound ){
+      sqlite3ErrorClear(pParse);
+      return 0;
+    }else{
+      return -1;
+    }
+  }
+  if( nc.hasAgg && pHasAgg ){
+    *pHasAgg = 1;
+  }
+
+  /* For a compound SELECT, we need to try to match the ORDER BY
+  ** expression against an expression in the result set
+  */
+  if( isCompound ){
+    for(i=0; i<pEList->nExpr; i++){
+      if( sqlite3ExprCompare(pEList->a[i].pExpr, pE) ){
+        return i+1;
+      }
+    }
+  }
+  return 0;
+}
+
+
+/*
+** Analyze and ORDER BY or GROUP BY clause in a simple SELECT statement.
+** Return the number of errors seen.
+**
+** Every term of the ORDER BY or GROUP BY clause needs to be an
+** expression.  If any expression is an integer constant, then
+** that expression is replaced by the corresponding 
+** expression from the result set.
+*/
+static int processOrderGroupBy(
+  Parse *pParse,        /* Parsing context.  Leave error messages here */
+  Select *pSelect,      /* The SELECT statement containing the clause */
+  ExprList *pOrderBy,   /* The ORDER BY or GROUP BY clause to be processed */
+  int isOrder,          /* 1 for ORDER BY.  0 for GROUP BY */
+  u8 *pHasAgg           /* Set to TRUE if any term contains an aggregate */
+){
+  int i;
+  sqlite3 *db = pParse->db;
+  ExprList *pEList;
+
+  if( pOrderBy==0 || pParse->db->mallocFailed ) return 0;
+#if SQLITE_MAX_COLUMN
+  if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
+    const char *zType = isOrder ? "ORDER" : "GROUP";
+    sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType);
+    return 1;
+  }
+#endif
+  pEList = pSelect->pEList;
+  if( pEList==0 ){
+    return 0;
+  }
+  for(i=0; i<pOrderBy->nExpr; i++){
+    int iCol;
+    Expr *pE = pOrderBy->a[i].pExpr;
+    if( sqlite3ExprIsInteger(pE, &iCol) ){
+      if( iCol<=0 || iCol>pEList->nExpr ){
+        const char *zType = isOrder ? "ORDER" : "GROUP";
+        sqlite3ErrorMsg(pParse, 
+           "%r %s BY term out of range - should be "
+           "between 1 and %d", i+1, zType, pEList->nExpr);
+        return 1;
+      }
+    }else{
+      iCol = matchOrderByTermToExprList(pParse, pSelect, pE, i+1, 0, pHasAgg);
+      if( iCol<0 ){
+        return 1;
+      }
+    }
+    if( iCol>0 ){
+      CollSeq *pColl = pE->pColl;
+      int flags = pE->flags & EP_ExpCollate;
+      sqlite3ExprDelete(db, pE);
+      pE = sqlite3ExprDup(db, pEList->a[iCol-1].pExpr);
+      pOrderBy->a[i].pExpr = pE;
+      if( pE && pColl && flags ){
+        pE->pColl = pColl;
+        pE->flags |= flags;
+      }
+    }
+  }
+  return 0;
+}
+
+/*
+** Analyze and ORDER BY or GROUP BY clause in a SELECT statement.  Return
+** the number of errors seen.
+**
+** If iTable>0 then make the N-th term of the ORDER BY clause refer to
+** the N-th column of table iTable.
+**
+** If iTable==0 then transform each term of the ORDER BY clause to refer
+** to a column of the result set by number.
+*/
+static int processCompoundOrderBy(
+  Parse *pParse,        /* Parsing context.  Leave error messages here */
+  Select *pSelect       /* The SELECT statement containing the ORDER BY */
+){
+  int i;
+  ExprList *pOrderBy;
+  ExprList *pEList;
+  sqlite3 *db;
+  int moreToDo = 1;
+
+  pOrderBy = pSelect->pOrderBy;
+  if( pOrderBy==0 ) return 0;
+  db = pParse->db;
+#if SQLITE_MAX_COLUMN
+  if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
+    sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause");
+    return 1;
+  }
+#endif
+  for(i=0; i<pOrderBy->nExpr; i++){
+    pOrderBy->a[i].done = 0;
+  }
+  while( pSelect->pPrior ){
+    pSelect = pSelect->pPrior;
+  }
+  while( pSelect && moreToDo ){
+    moreToDo = 0;
+    pEList = pSelect->pEList;
+    if( pEList==0 ){
+      return 1;
+    }
+    for(i=0; i<pOrderBy->nExpr; i++){
+      int iCol = -1;
+      Expr *pE, *pDup;
+      if( pOrderBy->a[i].done ) continue;
+      pE = pOrderBy->a[i].pExpr;
+      if( sqlite3ExprIsInteger(pE, &iCol) ){
+        if( iCol<0 || iCol>pEList->nExpr ){
+          sqlite3ErrorMsg(pParse, 
+             "%r ORDER BY term out of range - should be "
+             "between 1 and %d", i+1, pEList->nExpr);
+          return 1;
+        }
+      }else{
+        pDup = sqlite3ExprDup(db, pE);
+        if( !db->mallocFailed ){
+          assert(pDup);
+          iCol = matchOrderByTermToExprList(pParse, pSelect, pDup, i+1, 1, 0);
+        }
+        sqlite3ExprDelete(db, pDup);
+        if( iCol<0 ){
+          return 1;
+        }
+      }
+      if( iCol>0 ){
+        pE->op = TK_INTEGER;
+        pE->flags |= EP_IntValue;
+        pE->iTable = iCol;
+        pOrderBy->a[i].done = 1;
+      }else{
+        moreToDo = 1;
+      }
+    }
+    pSelect = pSelect->pNext;
+  }
+  for(i=0; i<pOrderBy->nExpr; i++){
+    if( pOrderBy->a[i].done==0 ){
+      sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any "
+            "column in the result set", i+1);
+      return 1;
+    }
+  }
+  return 0;
+}
+
+/*
+** Get a VDBE for the given parser context.  Create a new one if necessary.
+** If an error occurs, return NULL and leave a message in pParse.
+*/
+Vdbe *sqlite3GetVdbe(Parse *pParse){
+  Vdbe *v = pParse->pVdbe;
+  if( v==0 ){
+    v = pParse->pVdbe = sqlite3VdbeCreate(pParse->db);
+#ifndef SQLITE_OMIT_TRACE
+    if( v ){
+      sqlite3VdbeAddOp0(v, OP_Trace);
+    }
+#endif
+  }
+  return v;
+}
+
+
+/*
+** Compute the iLimit and iOffset fields of the SELECT based on the
+** pLimit and pOffset expressions.  pLimit and pOffset hold the expressions
+** that appear in the original SQL statement after the LIMIT and OFFSET
+** keywords.  Or NULL if those keywords are omitted. iLimit and iOffset 
+** are the integer memory register numbers for counters used to compute 
+** the limit and offset.  If there is no limit and/or offset, then 
+** iLimit and iOffset are negative.
+**
+** This routine changes the values of iLimit and iOffset only if
+** a limit or offset is defined by pLimit and pOffset.  iLimit and
+** iOffset should have been preset to appropriate default values
+** (usually but not always -1) prior to calling this routine.
+** Only if pLimit!=0 or pOffset!=0 do the limit registers get
+** redefined.  The UNION ALL operator uses this property to force
+** the reuse of the same limit and offset registers across multiple
+** SELECT statements.
+*/
+static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
+  Vdbe *v = 0;
+  int iLimit = 0;
+  int iOffset;
+  int addr1;
+  if( p->iLimit ) return;
+
+  /* 
+  ** "LIMIT -1" always shows all rows.  There is some
+  ** contraversy about what the correct behavior should be.
+  ** The current implementation interprets "LIMIT 0" to mean
+  ** no rows.
+  */
+  if( p->pLimit ){
+    p->iLimit = iLimit = ++pParse->nMem;
+    v = sqlite3GetVdbe(pParse);
+    if( v==0 ) return;
+    sqlite3ExprCode(pParse, p->pLimit, iLimit);
+    sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit);
+    VdbeComment((v, "LIMIT counter"));
+    sqlite3VdbeAddOp2(v, OP_IfZero, iLimit, iBreak);
+  }
+  if( p->pOffset ){
+    p->iOffset = iOffset = ++pParse->nMem;
+    if( p->pLimit ){
+      pParse->nMem++;   /* Allocate an extra register for limit+offset */
+    }
+    v = sqlite3GetVdbe(pParse);
+    if( v==0 ) return;
+    sqlite3ExprCode(pParse, p->pOffset, iOffset);
+    sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset);
+    VdbeComment((v, "OFFSET counter"));
+    addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iOffset);
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, iOffset);
+    sqlite3VdbeJumpHere(v, addr1);
+    if( p->pLimit ){
+      sqlite3VdbeAddOp3(v, OP_Add, iLimit, iOffset, iOffset+1);
+      VdbeComment((v, "LIMIT+OFFSET"));
+      addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iLimit);
+      sqlite3VdbeAddOp2(v, OP_Integer, -1, iOffset+1);
+      sqlite3VdbeJumpHere(v, addr1);
+    }
+  }
+}
+
+#ifndef SQLITE_OMIT_COMPOUND_SELECT
+/*
+** Return the appropriate collating sequence for the iCol-th column of
+** the result set for the compound-select statement "p".  Return NULL if
+** the column has no default collating sequence.
+**
+** The collating sequence for the compound select is taken from the
+** left-most term of the select that has a collating sequence.
+*/
+static CollSeq *multiSelectCollSeq(Parse *pParse, Select *p, int iCol){
+  CollSeq *pRet;
+  if( p->pPrior ){
+    pRet = multiSelectCollSeq(pParse, p->pPrior, iCol);
+  }else{
+    pRet = 0;
+  }
+  if( pRet==0 ){
+    pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr);
+  }
+  return pRet;
+}
+#endif /* SQLITE_OMIT_COMPOUND_SELECT */
+
+/* Forward reference */
+static int multiSelectOrderBy(
+  Parse *pParse,        /* Parsing context */
+  Select *p,            /* The right-most of SELECTs to be coded */
+  SelectDest *pDest     /* What to do with query results */
+);
+
+
+#ifndef SQLITE_OMIT_COMPOUND_SELECT
+/*
+** This routine is called to process a compound query form from
+** two or more separate queries using UNION, UNION ALL, EXCEPT, or
+** INTERSECT
+**
+** "p" points to the right-most of the two queries.  the query on the
+** left is p->pPrior.  The left query could also be a compound query
+** in which case this routine will be called recursively. 
+**
+** The results of the total query are to be written into a destination
+** of type eDest with parameter iParm.
+**
+** Example 1:  Consider a three-way compound SQL statement.
+**
+**     SELECT a FROM t1 UNION SELECT b FROM t2 UNION SELECT c FROM t3
+**
+** This statement is parsed up as follows:
+**
+**     SELECT c FROM t3
+**      |
+**      `----->  SELECT b FROM t2
+**                |
+**                `------>  SELECT a FROM t1
+**
+** The arrows in the diagram above represent the Select.pPrior pointer.
+** So if this routine is called with p equal to the t3 query, then
+** pPrior will be the t2 query.  p->op will be TK_UNION in this case.
+**
+** Notice that because of the way SQLite parses compound SELECTs, the
+** individual selects always group from left to right.
+*/
+static int multiSelect(
+  Parse *pParse,        /* Parsing context */
+  Select *p,            /* The right-most of SELECTs to be coded */
+  SelectDest *pDest     /* What to do with query results */
+){
+  int rc = SQLITE_OK;   /* Success code from a subroutine */
+  Select *pPrior;       /* Another SELECT immediately to our left */
+  Vdbe *v;              /* Generate code to this VDBE */
+  SelectDest dest;      /* Alternative data destination */
+  Select *pDelete = 0;  /* Chain of simple selects to delete */
+  sqlite3 *db;          /* Database connection */
+
+  /* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs.  Only
+  ** the last (right-most) SELECT in the series may have an ORDER BY or LIMIT.
+  */
+  assert( p && p->pPrior );  /* Calling function guarantees this much */
+  db = pParse->db;
+  pPrior = p->pPrior;
+  assert( pPrior->pRightmost!=pPrior );
+  assert( pPrior->pRightmost==p->pRightmost );
+  if( pPrior->pOrderBy ){
+    sqlite3ErrorMsg(pParse,"ORDER BY clause should come after %s not before",
+      selectOpName(p->op));
+    rc = 1;
+    goto multi_select_end;
+  }
+  if( pPrior->pLimit ){
+    sqlite3ErrorMsg(pParse,"LIMIT clause should come after %s not before",
+      selectOpName(p->op));
+    rc = 1;
+    goto multi_select_end;
+  }
+
+  v = sqlite3GetVdbe(pParse);
+  assert( v!=0 );  /* The VDBE already created by calling function */
+
+  /* Create the destination temporary table if necessary
+  */
+  dest = *pDest;
+  if( dest.eDest==SRT_EphemTab ){
+    assert( p->pEList );
+    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, dest.iParm, p->pEList->nExpr);
+    dest.eDest = SRT_Table;
+  }
+
+  /* Make sure all SELECTs in the statement have the same number of elements
+  ** in their result sets.
+  */
+  assert( p->pEList && pPrior->pEList );
+  if( p->pEList->nExpr!=pPrior->pEList->nExpr ){
+    sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
+      " do not have the same number of result columns", selectOpName(p->op));
+    rc = 1;
+    goto multi_select_end;
+  }
+
+  /* Compound SELECTs that have an ORDER BY clause are handled separately.
+  */
+  if( p->pOrderBy ){
+    return multiSelectOrderBy(pParse, p, pDest);
+  }
+
+  /* Generate code for the left and right SELECT statements.
+  */
+  switch( p->op ){
+    case TK_ALL: {
+      int addr = 0;
+      assert( !pPrior->pLimit );
+      pPrior->pLimit = p->pLimit;
+      pPrior->pOffset = p->pOffset;
+      rc = sqlite3Select(pParse, pPrior, &dest, 0, 0, 0);
+      p->pLimit = 0;
+      p->pOffset = 0;
+      if( rc ){
+        goto multi_select_end;
+      }
+      p->pPrior = 0;
+      p->iLimit = pPrior->iLimit;
+      p->iOffset = pPrior->iOffset;
+      if( p->iLimit ){
+        addr = sqlite3VdbeAddOp1(v, OP_IfZero, p->iLimit);
+        VdbeComment((v, "Jump ahead if LIMIT reached"));
+      }
+      rc = sqlite3Select(pParse, p, &dest, 0, 0, 0);
+      pDelete = p->pPrior;
+      p->pPrior = pPrior;
+      if( rc ){
+        goto multi_select_end;
+      }
+      if( addr ){
+        sqlite3VdbeJumpHere(v, addr);
+      }
+      break;
+    }
+    case TK_EXCEPT:
+    case TK_UNION: {
+      int unionTab;    /* Cursor number of the temporary table holding result */
+      int op = 0;      /* One of the SRT_ operations to apply to self */
+      int priorOp;     /* The SRT_ operation to apply to prior selects */
+      Expr *pLimit, *pOffset; /* Saved values of p->nLimit and p->nOffset */
+      int addr;
+      SelectDest uniondest;
+
+      priorOp = SRT_Union;
+      if( dest.eDest==priorOp && !p->pLimit && !p->pOffset ){
+        /* We can reuse a temporary table generated by a SELECT to our
+        ** right.
+        */
+        unionTab = dest.iParm;
+      }else{
+        /* We will need to create our own temporary table to hold the
+        ** intermediate results.
+        */
+        unionTab = pParse->nTab++;
+        assert( p->pOrderBy==0 );
+        addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, unionTab, 0);
+        assert( p->addrOpenEphm[0] == -1 );
+        p->addrOpenEphm[0] = addr;
+        p->pRightmost->usesEphm = 1;
+        assert( p->pEList );
+      }
+
+      /* Code the SELECT statements to our left
+      */
+      assert( !pPrior->pOrderBy );
+      sqlite3SelectDestInit(&uniondest, priorOp, unionTab);
+      rc = sqlite3Select(pParse, pPrior, &uniondest, 0, 0, 0);
+      if( rc ){
+        goto multi_select_end;
+      }
+
+      /* Code the current SELECT statement
+      */
+      if( p->op==TK_EXCEPT ){
+        op = SRT_Except;
+      }else{
+        assert( p->op==TK_UNION );
+        op = SRT_Union;
+      }
+      p->pPrior = 0;
+      p->disallowOrderBy = 0;
+      pLimit = p->pLimit;
+      p->pLimit = 0;
+      pOffset = p->pOffset;
+      p->pOffset = 0;
+      uniondest.eDest = op;
+      rc = sqlite3Select(pParse, p, &uniondest, 0, 0, 0);
+      /* Query flattening in sqlite3Select() might refill p->pOrderBy.
+      ** Be sure to delete p->pOrderBy, therefore, to avoid a memory leak. */
+      sqlite3ExprListDelete(db, p->pOrderBy);
+      pDelete = p->pPrior;
+      p->pPrior = pPrior;
+      p->pOrderBy = 0;
+      sqlite3ExprDelete(db, p->pLimit);
+      p->pLimit = pLimit;
+      p->pOffset = pOffset;
+      p->iLimit = 0;
+      p->iOffset = 0;
+      if( rc ){
+        goto multi_select_end;
+      }
+
+
+      /* Convert the data in the temporary table into whatever form
+      ** it is that we currently need.
+      */      
+      if( dest.eDest!=priorOp || unionTab!=dest.iParm ){
+        int iCont, iBreak, iStart;
+        assert( p->pEList );
+        if( dest.eDest==SRT_Callback ){
+          Select *pFirst = p;
+          while( pFirst->pPrior ) pFirst = pFirst->pPrior;
+          generateColumnNames(pParse, 0, pFirst->pEList);
+        }
+        iBreak = sqlite3VdbeMakeLabel(v);
+        iCont = sqlite3VdbeMakeLabel(v);
+        computeLimitRegisters(pParse, p, iBreak);
+        sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak);
+        iStart = sqlite3VdbeCurrentAddr(v);
+        selectInnerLoop(pParse, p, p->pEList, unionTab, p->pEList->nExpr,
+                        0, -1, &dest, iCont, iBreak);
+        sqlite3VdbeResolveLabel(v, iCont);
+        sqlite3VdbeAddOp2(v, OP_Next, unionTab, iStart);
+        sqlite3VdbeResolveLabel(v, iBreak);
+        sqlite3VdbeAddOp2(v, OP_Close, unionTab, 0);
+      }
+      break;
+    }
+    case TK_INTERSECT: {
+      int tab1, tab2;
+      int iCont, iBreak, iStart;
+      Expr *pLimit, *pOffset;
+      int addr;
+      SelectDest intersectdest;
+      int r1;
+
+      /* INTERSECT is different from the others since it requires
+      ** two temporary tables.  Hence it has its own case.  Begin
+      ** by allocating the tables we will need.
+      */
+      tab1 = pParse->nTab++;
+      tab2 = pParse->nTab++;
+      assert( p->pOrderBy==0 );
+
+      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab1, 0);
+      assert( p->addrOpenEphm[0] == -1 );
+      p->addrOpenEphm[0] = addr;
+      p->pRightmost->usesEphm = 1;
+      assert( p->pEList );
+
+      /* Code the SELECTs to our left into temporary table "tab1".
+      */
+      sqlite3SelectDestInit(&intersectdest, SRT_Union, tab1);
+      rc = sqlite3Select(pParse, pPrior, &intersectdest, 0, 0, 0);
+      if( rc ){
+        goto multi_select_end;
+      }
+
+      /* Code the current SELECT into temporary table "tab2"
+      */
+      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab2, 0);
+      assert( p->addrOpenEphm[1] == -1 );
+      p->addrOpenEphm[1] = addr;
+      p->pPrior = 0;
+      pLimit = p->pLimit;
+      p->pLimit = 0;
+      pOffset = p->pOffset;
+      p->pOffset = 0;
+      intersectdest.iParm = tab2;
+      rc = sqlite3Select(pParse, p, &intersectdest, 0, 0, 0);
+      pDelete = p->pPrior;
+      p->pPrior = pPrior;
+      sqlite3ExprDelete(db, p->pLimit);
+      p->pLimit = pLimit;
+      p->pOffset = pOffset;
+      if( rc ){
+        goto multi_select_end;
+      }
+
+      /* Generate code to take the intersection of the two temporary
+      ** tables.
+      */
+      assert( p->pEList );
+      if( dest.eDest==SRT_Callback ){
+        Select *pFirst = p;
+        while( pFirst->pPrior ) pFirst = pFirst->pPrior;
+        generateColumnNames(pParse, 0, pFirst->pEList);
+      }
+      iBreak = sqlite3VdbeMakeLabel(v);
+      iCont = sqlite3VdbeMakeLabel(v);
+      computeLimitRegisters(pParse, p, iBreak);
+      sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak);
+      r1 = sqlite3GetTempReg(pParse);
+      iStart = sqlite3VdbeAddOp2(v, OP_RowKey, tab1, r1);
+      sqlite3VdbeAddOp3(v, OP_NotFound, tab2, iCont, r1);
+      sqlite3ReleaseTempReg(pParse, r1);
+      selectInnerLoop(pParse, p, p->pEList, tab1, p->pEList->nExpr,
+                      0, -1, &dest, iCont, iBreak);
+      sqlite3VdbeResolveLabel(v, iCont);
+      sqlite3VdbeAddOp2(v, OP_Next, tab1, iStart);
+      sqlite3VdbeResolveLabel(v, iBreak);
+      sqlite3VdbeAddOp2(v, OP_Close, tab2, 0);
+      sqlite3VdbeAddOp2(v, OP_Close, tab1, 0);
+      break;
+    }
+  }
+
+  /* Compute collating sequences used by 
+  ** temporary tables needed to implement the compound select.
+  ** Attach the KeyInfo structure to all temporary tables.
+  **
+  ** This section is run by the right-most SELECT statement only.
+  ** SELECT statements to the left always skip this part.  The right-most
+  ** SELECT might also skip this part if it has no ORDER BY clause and
+  ** no temp tables are required.
+  */
+  if( p->usesEphm ){
+    int i;                        /* Loop counter */
+    KeyInfo *pKeyInfo;            /* Collating sequence for the result set */
+    Select *pLoop;                /* For looping through SELECT statements */
+    CollSeq **apColl;             /* For looping through pKeyInfo->aColl[] */
+    int nCol;                     /* Number of columns in result set */
+
+    assert( p->pRightmost==p );
+    nCol = p->pEList->nExpr;
+    pKeyInfo = sqlite3DbMallocZero(db,
+                       sizeof(*pKeyInfo)+nCol*(sizeof(CollSeq*) + 1));
+    if( !pKeyInfo ){
+      rc = SQLITE_NOMEM;
+      goto multi_select_end;
+    }
+
+    pKeyInfo->enc = ENC(db);
+    pKeyInfo->nField = nCol;
+
+    for(i=0, apColl=pKeyInfo->aColl; i<nCol; i++, apColl++){
+      *apColl = multiSelectCollSeq(pParse, p, i);
+      if( 0==*apColl ){
+        *apColl = db->pDfltColl;
+      }
+    }
+
+    for(pLoop=p; pLoop; pLoop=pLoop->pPrior){
+      for(i=0; i<2; i++){
+        int addr = pLoop->addrOpenEphm[i];
+        if( addr<0 ){
+          /* If [0] is unused then [1] is also unused.  So we can
+          ** always safely abort as soon as the first unused slot is found */
+          assert( pLoop->addrOpenEphm[1]<0 );
+          break;
+        }
+        sqlite3VdbeChangeP2(v, addr, nCol);
+        sqlite3VdbeChangeP4(v, addr, (char*)pKeyInfo, P4_KEYINFO);
+        pLoop->addrOpenEphm[i] = -1;
+      }
+    }
+    sqlite3DbFree(db, pKeyInfo);
+  }
+
+multi_select_end:
+  pDest->iMem = dest.iMem;
+  pDest->nMem = dest.nMem;
+  sqlite3SelectDelete(db, pDelete);
+  return rc;
+}
+#endif /* SQLITE_OMIT_COMPOUND_SELECT */
+
+/*
+** Code an output subroutine for a coroutine implementation of a
+** SELECT statment.
+**
+** The data to be output is contained in pIn->iMem.  There are
+** pIn->nMem columns to be output.  pDest is where the output should
+** be sent.
+**
+** regReturn is the number of the register holding the subroutine
+** return address.
+**
+** If regPrev>0 then it is a the first register in a vector that
+** records the previous output.  mem[regPrev] is a flag that is false
+** if there has been no previous output.  If regPrev>0 then code is
+** generated to suppress duplicates.  pKeyInfo is used for comparing
+** keys.
+**
+** If the LIMIT found in p->iLimit is reached, jump immediately to
+** iBreak.
+*/
+static int generateOutputSubroutine(
+  Parse *pParse,          /* Parsing context */
+  Select *p,              /* The SELECT statement */
+  SelectDest *pIn,        /* Coroutine supplying data */
+  SelectDest *pDest,      /* Where to send the data */
+  int regReturn,          /* The return address register */
+  int regPrev,            /* Previous result register.  No uniqueness if 0 */
+  KeyInfo *pKeyInfo,      /* For comparing with previous entry */
+  int p4type,             /* The p4 type for pKeyInfo */
+  int iBreak              /* Jump here if we hit the LIMIT */
+){
+  Vdbe *v = pParse->pVdbe;
+  int iContinue;
+  int addr;
+
+  addr = sqlite3VdbeCurrentAddr(v);
+  iContinue = sqlite3VdbeMakeLabel(v);
+
+  /* Suppress duplicates for UNION, EXCEPT, and INTERSECT 
+  */
+  if( regPrev ){
+    int j1, j2;
+    j1 = sqlite3VdbeAddOp1(v, OP_IfNot, regPrev);
+    j2 = sqlite3VdbeAddOp4(v, OP_Compare, pIn->iMem, regPrev+1, pIn->nMem,
+                              (char*)pKeyInfo, p4type);
+    sqlite3VdbeAddOp3(v, OP_Jump, j2+2, iContinue, j2+2);
+    sqlite3VdbeJumpHere(v, j1);
+    sqlite3ExprCodeCopy(pParse, pIn->iMem, regPrev+1, pIn->nMem);
+    sqlite3VdbeAddOp2(v, OP_Integer, 1, regPrev);
+  }
+  if( pParse->db->mallocFailed ) return 0;
+
+  /* Suppress the the first OFFSET entries if there is an OFFSET clause
+  */
+  codeOffset(v, p, iContinue);
+
+  switch( pDest->eDest ){
+    /* Store the result as data using a unique key.
+    */
+    case SRT_Table:
+    case SRT_EphemTab: {
+      int r1 = sqlite3GetTempReg(pParse);
+      int r2 = sqlite3GetTempReg(pParse);
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, pIn->iMem, pIn->nMem, r1);
+      sqlite3VdbeAddOp2(v, OP_NewRowid, pDest->iParm, r2);
+      sqlite3VdbeAddOp3(v, OP_Insert, pDest->iParm, r1, r2);
+      sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
+      sqlite3ReleaseTempReg(pParse, r2);
+      sqlite3ReleaseTempReg(pParse, r1);
+      break;
+    }
+
+#ifndef SQLITE_OMIT_SUBQUERY
+    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
+    ** then there should be a single item on the stack.  Write this
+    ** item into the set table with bogus data.
+    */
+    case SRT_Set: {
+      int r1;
+      assert( pIn->nMem==1 );
+      p->affinity = 
+         sqlite3CompareAffinity(p->pEList->a[0].pExpr, pDest->affinity);
+      r1 = sqlite3GetTempReg(pParse);
+      sqlite3VdbeAddOp4(v, OP_MakeRecord, pIn->iMem, 1, r1, &p->affinity, 1);
+      sqlite3ExprCacheAffinityChange(pParse, pIn->iMem, 1);
+      sqlite3VdbeAddOp2(v, OP_IdxInsert, pDest->iParm, r1);
+      sqlite3ReleaseTempReg(pParse, r1);
+      break;
+    }
+
+#if 0  /* Never occurs on an ORDER BY query */
+    /* If any row exist in the result set, record that fact and abort.
+    */
+    case SRT_Exists: {
+      sqlite3VdbeAddOp2(v, OP_Integer, 1, pDest->iParm);
+      /* The LIMIT clause will terminate the loop for us */
+      break;
+    }
+#endif
+
+    /* If this is a scalar select that is part of an expression, then
+    ** store the results in the appropriate memory cell and break out
+    ** of the scan loop.
+    */
+    case SRT_Mem: {
+      assert( pIn->nMem==1 );
+      sqlite3ExprCodeMove(pParse, pIn->iMem, pDest->iParm, 1);
+      /* The LIMIT clause will jump out of the loop for us */
+      break;
+    }
+#endif /* #ifndef SQLITE_OMIT_SUBQUERY */
+
+    /* Send the data to the callback function or to a subroutine.  In the
+    ** case of a subroutine, the subroutine itself is responsible for
+    ** popping the data from the stack.
+    */
+    case SRT_Coroutine: {
+      if( pDest->iMem==0 ){
+        pDest->iMem = sqlite3GetTempRange(pParse, pIn->nMem);
+        pDest->nMem = pIn->nMem;
+      }
+      sqlite3ExprCodeMove(pParse, pIn->iMem, pDest->iMem, pDest->nMem);
+      sqlite3VdbeAddOp1(v, OP_Yield, pDest->iParm);
+      break;
+    }
+
+    case SRT_Callback: {
+      sqlite3VdbeAddOp2(v, OP_ResultRow, pIn->iMem, pIn->nMem);
+      sqlite3ExprCacheAffinityChange(pParse, pIn->iMem, pIn->nMem);
+      break;
+    }
+
+#if !defined(SQLITE_OMIT_TRIGGER)
+    /* Discard the results.  This is used for SELECT statements inside
+    ** the body of a TRIGGER.  The purpose of such selects is to call
+    ** user-defined functions that have side effects.  We do not care
+    ** about the actual results of the select.
+    */
+    default: {
+      break;
+    }
+#endif
+  }
+
+  /* Jump to the end of the loop if the LIMIT is reached.
+  */
+  if( p->iLimit ){
+    sqlite3VdbeAddOp2(v, OP_AddImm, p->iLimit, -1);
+    sqlite3VdbeAddOp2(v, OP_IfZero, p->iLimit, iBreak);
+  }
+
+  /* Generate the subroutine return
+  */
+  sqlite3VdbeResolveLabel(v, iContinue);
+  sqlite3VdbeAddOp1(v, OP_Return, regReturn);
+
+  return addr;
+}
+
+/*
+** Alternative compound select code generator for cases when there
+** is an ORDER BY clause.
+**
+** We assume a query of the following form:
+**
+**      <selectA>  <operator>  <selectB>  ORDER BY <orderbylist>
+**
+** <operator> is one of UNION ALL, UNION, EXCEPT, or INTERSECT.  The idea
+** is to code both <selectA> and <selectB> with the ORDER BY clause as
+** co-routines.  Then run the co-routines in parallel and merge the results
+** into the output.  In addition to the two coroutines (called selectA and
+** selectB) there are 7 subroutines:
+**
+**    outA:    Move the output of the selectA coroutine into the output
+**             of the compound query.
+**
+**    outB:    Move the output of the selectB coroutine into the output
+**             of the compound query.  (Only generated for UNION and
+**             UNION ALL.  EXCEPT and INSERTSECT never output a row that
+**             appears only in B.)
+**
+**    AltB:    Called when there is data from both coroutines and A<B.
+**
+**    AeqB:    Called when there is data from both coroutines and A==B.
+**
+**    AgtB:    Called when there is data from both coroutines and A>B.
+**
+**    EofA:    Called when data is exhausted from selectA.
+**
+**    EofB:    Called when data is exhausted from selectB.
+**
+** The implementation of the latter five subroutines depend on which 
+** <operator> is used:
+**
+**
+**             UNION ALL         UNION            EXCEPT          INTERSECT
+**          -------------  -----------------  --------------  -----------------
+**   AltB:   outA, nextA      outA, nextA       outA, nextA         nextA
+**
+**   AeqB:   outA, nextA         nextA             nextA         outA, nextA
+**
+**   AgtB:   outB, nextB      outB, nextB          nextB            nextB
+**
+**   EofA:   outB, nextB      outB, nextB          halt             halt
+**
+**   EofB:   outA, nextA      outA, nextA       outA, nextA         halt
+**
+** In the AltB, AeqB, and AgtB subroutines, an EOF on A following nextA
+** causes an immediate jump to EofA and an EOF on B following nextB causes
+** an immediate jump to EofB.  Within EofA and EofB, and EOF on entry or
+** following nextX causes a jump to the end of the select processing.
+**
+** Duplicate removal in the UNION, EXCEPT, and INTERSECT cases is handled
+** within the output subroutine.  The regPrev register set holds the previously
+** output value.  A comparison is made against this value and the output
+** is skipped if the next results would be the same as the previous.
+**
+** The implementation plan is to implement the two coroutines and seven
+** subroutines first, then put the control logic at the bottom.  Like this:
+**
+**          goto Init
+**     coA: coroutine for left query (A)
+**     coB: coroutine for right query (B)
+**    outA: output one row of A
+**    outB: output one row of B (UNION and UNION ALL only)
+**    EofA: ...
+**    EofB: ...
+**    AltB: ...
+**    AeqB: ...
+**    AgtB: ...
+**    Init: initialize coroutine registers
+**          yield coA
+**          if eof(A) goto EofA
+**          yield coB
+**          if eof(B) goto EofB
+**    Cmpr: Compare A, B
+**          Jump AltB, AeqB, AgtB
+**     End: ...
+**
+** We call AltB, AeqB, AgtB, EofA, and EofB "subroutines" but they are not
+** actually called using Gosub and they do not Return.  EofA and EofB loop
+** until all data is exhausted then jump to the "end" labe.  AltB, AeqB,
+** and AgtB jump to either L2 or to one of EofA or EofB.
+*/
+#ifndef SQLITE_OMIT_COMPOUND_SELECT
+static int multiSelectOrderBy(
+  Parse *pParse,        /* Parsing context */
+  Select *p,            /* The right-most of SELECTs to be coded */
+  SelectDest *pDest     /* What to do with query results */
+){
+  int i, j;             /* Loop counters */
+  Select *pPrior;       /* Another SELECT immediately to our left */
+  Vdbe *v;              /* Generate code to this VDBE */
+  SelectDest destA;     /* Destination for coroutine A */
+  SelectDest destB;     /* Destination for coroutine B */
+  int regAddrA;         /* Address register for select-A coroutine */
+  int regEofA;          /* Flag to indicate when select-A is complete */
+  int regAddrB;         /* Address register for select-B coroutine */
+  int regEofB;          /* Flag to indicate when select-B is complete */
+  int addrSelectA;      /* Address of the select-A coroutine */
+  int addrSelectB;      /* Address of the select-B coroutine */
+  int regOutA;          /* Address register for the output-A subroutine */
+  int regOutB;          /* Address register for the output-B subroutine */
+  int addrOutA;         /* Address of the output-A subroutine */
+  int addrOutB;         /* Address of the output-B subroutine */
+  int addrEofA;         /* Address of the select-A-exhausted subroutine */
+  int addrEofB;         /* Address of the select-B-exhausted subroutine */
+  int addrAltB;         /* Address of the A<B subroutine */
+  int addrAeqB;         /* Address of the A==B subroutine */
+  int addrAgtB;         /* Address of the A>B subroutine */
+  int regLimitA;        /* Limit register for select-A */
+  int regLimitB;        /* Limit register for select-A */
+  int regPrev;          /* A range of registers to hold previous output */
+  int savedLimit;       /* Saved value of p->iLimit */
+  int savedOffset;      /* Saved value of p->iOffset */
+  int labelCmpr;        /* Label for the start of the merge algorithm */
+  int labelEnd;         /* Label for the end of the overall SELECT stmt */
+  int j1;               /* Jump instructions that get retargetted */
+  int op;               /* One of TK_ALL, TK_UNION, TK_EXCEPT, TK_INTERSECT */
+  KeyInfo *pKeyDup;     /* Comparison information for duplicate removal */
+  KeyInfo *pKeyMerge;   /* Comparison information for merging rows */
+  sqlite3 *db;          /* Database connection */
+  ExprList *pOrderBy;   /* The ORDER BY clause */
+  int nOrderBy;         /* Number of terms in the ORDER BY clause */
+  int *aPermute;        /* Mapping from ORDER BY terms to result set columns */
+  u8 NotUsed;           /* Dummy variables */
+
+  assert( p->pOrderBy!=0 );
+  db = pParse->db;
+  v = pParse->pVdbe;
+  if( v==0 ) return SQLITE_NOMEM;
+  labelEnd = sqlite3VdbeMakeLabel(v);
+  labelCmpr = sqlite3VdbeMakeLabel(v);
+
+
+  /* Patch up the ORDER BY clause
+  */
+  op = p->op;  
+  pPrior = p->pPrior;
+  assert( pPrior->pOrderBy==0 );
+  pOrderBy = p->pOrderBy;
+  assert( pOrderBy );
+  if( processCompoundOrderBy(pParse, p) ){
+    return SQLITE_ERROR;
+  }
+  nOrderBy = pOrderBy->nExpr;
+
+  /* For operators other than UNION ALL we have to make sure that
+  ** the ORDER BY clause covers every term of the result set.  Add
+  ** terms to the ORDER BY clause as necessary.
+  */
+  if( op!=TK_ALL ){
+    for(i=1; db->mallocFailed==0 && i<=p->pEList->nExpr; i++){
+      for(j=0; j<nOrderBy; j++){
+        Expr *pTerm = pOrderBy->a[j].pExpr;
+        assert( pTerm->op==TK_INTEGER );
+        assert( (pTerm->flags & EP_IntValue)!=0 );
+        if( pTerm->iTable==i ) break;
+      }
+      if( j==nOrderBy ){
+        Expr *pNew = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, 0);
+        if( pNew==0 ) return SQLITE_NOMEM;
+        pNew->flags |= EP_IntValue;
+        pNew->iTable = i;
+        pOrderBy = sqlite3ExprListAppend(pParse, pOrderBy, pNew, 0);
+        nOrderBy++;
+      }
+    }
+  }
+
+  /* Compute the comparison permutation and keyinfo that is used with
+  ** the permutation in order to comparisons to determine if the next
+  ** row of results comes from selectA or selectB.  Also add explicit
+  ** collations to the ORDER BY clause terms so that when the subqueries
+  ** to the right and the left are evaluated, they use the correct
+  ** collation.
+  */
+  aPermute = sqlite3DbMallocRaw(db, sizeof(int)*nOrderBy);
+  if( aPermute ){
+    for(i=0; i<nOrderBy; i++){
+      Expr *pTerm = pOrderBy->a[i].pExpr;
+      assert( pTerm->op==TK_INTEGER );
+      assert( (pTerm->flags & EP_IntValue)!=0 );
+      aPermute[i] = pTerm->iTable-1;
+      assert( aPermute[i]>=0 && aPermute[i]<p->pEList->nExpr );
+    }
+    pKeyMerge =
+      sqlite3DbMallocRaw(db, sizeof(*pKeyMerge)+nOrderBy*(sizeof(CollSeq*)+1));
+    if( pKeyMerge ){
+      pKeyMerge->aSortOrder = (u8*)&pKeyMerge->aColl[nOrderBy];
+      pKeyMerge->nField = nOrderBy;
+      pKeyMerge->enc = ENC(db);
+      for(i=0; i<nOrderBy; i++){
+        CollSeq *pColl;
+        Expr *pTerm = pOrderBy->a[i].pExpr;
+        if( pTerm->flags & EP_ExpCollate ){
+          pColl = pTerm->pColl;
+        }else{
+          pColl = multiSelectCollSeq(pParse, p, aPermute[i]);
+          pTerm->flags |= EP_ExpCollate;
+          pTerm->pColl = pColl;
+        }
+        pKeyMerge->aColl[i] = pColl;
+        pKeyMerge->aSortOrder[i] = pOrderBy->a[i].sortOrder;
+      }
+    }
+  }else{
+    pKeyMerge = 0;
+  }
+
+  /* Reattach the ORDER BY clause to the query.
+  */
+  p->pOrderBy = pOrderBy;
+  pPrior->pOrderBy = sqlite3ExprListDup(pParse->db, pOrderBy);
+
+  /* Allocate a range of temporary registers and the KeyInfo needed
+  ** for the logic that removes duplicate result rows when the
+  ** operator is UNION, EXCEPT, or INTERSECT (but not UNION ALL).
+  */
+  if( op==TK_ALL ){
+    regPrev = 0;
+  }else{
+    int nExpr = p->pEList->nExpr;
+    assert( nOrderBy>=nExpr );
+    regPrev = sqlite3GetTempRange(pParse, nExpr+1);
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, regPrev);
+    pKeyDup = sqlite3DbMallocZero(db,
+                  sizeof(*pKeyDup) + nExpr*(sizeof(CollSeq*)+1) );
+    if( pKeyDup ){
+      pKeyDup->aSortOrder = (u8*)&pKeyDup->aColl[nExpr];
+      pKeyDup->nField = nExpr;
+      pKeyDup->enc = ENC(db);
+      for(i=0; i<nExpr; i++){
+        pKeyDup->aColl[i] = multiSelectCollSeq(pParse, p, i);
+        pKeyDup->aSortOrder[i] = 0;
+      }
+    }
+  }
+ 
+  /* Separate the left and the right query from one another
+  */
+  p->pPrior = 0;
+  pPrior->pRightmost = 0;
+  processOrderGroupBy(pParse, p, p->pOrderBy, 1, &NotUsed);
+  if( pPrior->pPrior==0 ){
+    processOrderGroupBy(pParse, pPrior, pPrior->pOrderBy, 1, &NotUsed);
+  }
+
+  /* Compute the limit registers */
+  computeLimitRegisters(pParse, p, labelEnd);
+  if( p->iLimit && op==TK_ALL ){
+    regLimitA = ++pParse->nMem;
+    regLimitB = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Copy, p->iOffset ? p->iOffset+1 : p->iLimit,
+                                  regLimitA);
+    sqlite3VdbeAddOp2(v, OP_Copy, regLimitA, regLimitB);
+  }else{
+    regLimitA = regLimitB = 0;
+  }
+  sqlite3ExprDelete(db, p->pLimit);
+  p->pLimit = 0;
+  sqlite3ExprDelete(db, p->pOffset);
+  p->pOffset = 0;
+
+  regAddrA = ++pParse->nMem;
+  regEofA = ++pParse->nMem;
+  regAddrB = ++pParse->nMem;
+  regEofB = ++pParse->nMem;
+  regOutA = ++pParse->nMem;
+  regOutB = ++pParse->nMem;
+  sqlite3SelectDestInit(&destA, SRT_Coroutine, regAddrA);
+  sqlite3SelectDestInit(&destB, SRT_Coroutine, regAddrB);
+
+  /* Jump past the various subroutines and coroutines to the main
+  ** merge loop
+  */
+  j1 = sqlite3VdbeAddOp0(v, OP_Goto);
+  addrSelectA = sqlite3VdbeCurrentAddr(v);
+
+
+  /* Generate a coroutine to evaluate the SELECT statement to the
+  ** left of the compound operator - the "A" select.
+  */
+  VdbeNoopComment((v, "Begin coroutine for left SELECT"));
+  pPrior->iLimit = regLimitA;
+  sqlite3Select(pParse, pPrior, &destA, 0, 0, 0);
+  sqlite3VdbeAddOp2(v, OP_Integer, 1, regEofA);
+  sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
+  VdbeNoopComment((v, "End coroutine for left SELECT"));
+
+  /* Generate a coroutine to evaluate the SELECT statement on 
+  ** the right - the "B" select
+  */
+  addrSelectB = sqlite3VdbeCurrentAddr(v);
+  VdbeNoopComment((v, "Begin coroutine for right SELECT"));
+  savedLimit = p->iLimit;
+  savedOffset = p->iOffset;
+  p->iLimit = regLimitB;
+  p->iOffset = 0;  
+  sqlite3Select(pParse, p, &destB, 0, 0, 0);
+  p->iLimit = savedLimit;
+  p->iOffset = savedOffset;
+  sqlite3VdbeAddOp2(v, OP_Integer, 1, regEofB);
+  sqlite3VdbeAddOp1(v, OP_Yield, regAddrB);
+  VdbeNoopComment((v, "End coroutine for right SELECT"));
+
+  /* Generate a subroutine that outputs the current row of the A
+  ** select as the next output row of the compound select.
+  */
+  VdbeNoopComment((v, "Output routine for A"));
+  addrOutA = generateOutputSubroutine(pParse,
+                 p, &destA, pDest, regOutA,
+                 regPrev, pKeyDup, P4_KEYINFO_HANDOFF, labelEnd);
+  
+  /* Generate a subroutine that outputs the current row of the B
+  ** select as the next output row of the compound select.
+  */
+  if( op==TK_ALL || op==TK_UNION ){
+    VdbeNoopComment((v, "Output routine for B"));
+    addrOutB = generateOutputSubroutine(pParse,
+                 p, &destB, pDest, regOutB,
+                 regPrev, pKeyDup, P4_KEYINFO_STATIC, labelEnd);
+  }
+
+  /* Generate a subroutine to run when the results from select A
+  ** are exhausted and only data in select B remains.
+  */
+  VdbeNoopComment((v, "eof-A subroutine"));
+  if( op==TK_EXCEPT || op==TK_INTERSECT ){
+    addrEofA = sqlite3VdbeAddOp2(v, OP_Goto, 0, labelEnd);
+  }else{  
+    addrEofA = sqlite3VdbeAddOp2(v, OP_If, regEofB, labelEnd);
+    sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
+    sqlite3VdbeAddOp1(v, OP_Yield, regAddrB);
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrEofA);
+  }
+
+  /* Generate a subroutine to run when the results from select B
+  ** are exhausted and only data in select A remains.
+  */
+  if( op==TK_INTERSECT ){
+    addrEofB = addrEofA;
+  }else{  
+    VdbeNoopComment((v, "eof-B subroutine"));
+    addrEofB = sqlite3VdbeAddOp2(v, OP_If, regEofA, labelEnd);
+    sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
+    sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrEofB);
+  }
+
+  /* Generate code to handle the case of A<B
+  */
+  VdbeNoopComment((v, "A-lt-B subroutine"));
+  addrAltB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
+  sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
+  sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA);
+  sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCmpr);
+
+  /* Generate code to handle the case of A==B
+  */
+  if( op==TK_ALL ){
+    addrAeqB = addrAltB;
+  }else if( op==TK_INTERSECT ){
+    addrAeqB = addrAltB;
+    addrAltB++;
+  }else{
+    VdbeNoopComment((v, "A-eq-B subroutine"));
+    addrAeqB =
+    sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
+    sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA);
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCmpr);
+  }
+
+  /* Generate code to handle the case of A>B
+  */
+  VdbeNoopComment((v, "A-gt-B subroutine"));
+  addrAgtB = sqlite3VdbeCurrentAddr(v);
+  if( op==TK_ALL || op==TK_UNION ){
+    sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
+  }
+  sqlite3VdbeAddOp1(v, OP_Yield, regAddrB);
+  sqlite3VdbeAddOp2(v, OP_If, regEofB, addrEofB);
+  sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCmpr);
+
+  /* This code runs once to initialize everything.
+  */
+  sqlite3VdbeJumpHere(v, j1);
+  sqlite3VdbeAddOp2(v, OP_Integer, 0, regEofA);
+  sqlite3VdbeAddOp2(v, OP_Integer, 0, regEofB);
+  sqlite3VdbeAddOp2(v, OP_Gosub, regAddrA, addrSelectA);
+  sqlite3VdbeAddOp2(v, OP_Gosub, regAddrB, addrSelectB);
+  sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA);
+  sqlite3VdbeAddOp2(v, OP_If, regEofB, addrEofB);
+
+  /* Implement the main merge loop
+  */
+  sqlite3VdbeResolveLabel(v, labelCmpr);
+  sqlite3VdbeAddOp4(v, OP_Permutation, 0, 0, 0, (char*)aPermute, P4_INTARRAY);
+  sqlite3VdbeAddOp4(v, OP_Compare, destA.iMem, destB.iMem, nOrderBy,
+                         (char*)pKeyMerge, P4_KEYINFO_HANDOFF);
+  sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB);
+
+  /* Release temporary registers
+  */
+  if( regPrev ){
+    sqlite3ReleaseTempRange(pParse, regPrev, nOrderBy+1);
+  }
+
+  /* Jump to the this point in order to terminate the query.
+  */
+  sqlite3VdbeResolveLabel(v, labelEnd);
+
+  /* Set the number of output columns
+  */
+  if( pDest->eDest==SRT_Callback ){
+    Select *pFirst = pPrior;
+    while( pFirst->pPrior ) pFirst = pFirst->pPrior;
+    generateColumnNames(pParse, 0, pFirst->pEList);
+  }
+
+  /* Reassembly the compound query so that it will be freed correctly
+  ** by the calling function */
+  if( p->pPrior ){
+    sqlite3SelectDelete(db, p->pPrior);
+  }
+  p->pPrior = pPrior;
+
+  /*** TBD:  Insert subroutine calls to close cursors on incomplete
+  **** subqueries ****/
+  return SQLITE_OK;
+}
+#endif
+
+#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
+/* Forward Declarations */
+static void substExprList(sqlite3*, ExprList*, int, ExprList*);
+static void substSelect(sqlite3*, Select *, int, ExprList *);
+
+/*
+** Scan through the expression pExpr.  Replace every reference to
+** a column in table number iTable with a copy of the iColumn-th
+** entry in pEList.  (But leave references to the ROWID column 
+** unchanged.)
+**
+** This routine is part of the flattening procedure.  A subquery
+** whose result set is defined by pEList appears as entry in the
+** FROM clause of a SELECT such that the VDBE cursor assigned to that
+** FORM clause entry is iTable.  This routine make the necessary 
+** changes to pExpr so that it refers directly to the source table
+** of the subquery rather the result set of the subquery.
+*/
+static void substExpr(
+  sqlite3 *db,        /* Report malloc errors to this connection */
+  Expr *pExpr,        /* Expr in which substitution occurs */
+  int iTable,         /* Table to be substituted */
+  ExprList *pEList    /* Substitute expressions */
+){
+  if( pExpr==0 ) return;
+  if( pExpr->op==TK_COLUMN && pExpr->iTable==iTable ){
+    if( pExpr->iColumn<0 ){
+      pExpr->op = TK_NULL;
+    }else{
+      Expr *pNew;
+      assert( pEList!=0 && pExpr->iColumn<pEList->nExpr );
+      assert( pExpr->pLeft==0 && pExpr->pRight==0 && pExpr->pList==0 );
+      pNew = pEList->a[pExpr->iColumn].pExpr;
+      assert( pNew!=0 );
+      pExpr->op = pNew->op;
+      assert( pExpr->pLeft==0 );
+      pExpr->pLeft = sqlite3ExprDup(db, pNew->pLeft);
+      assert( pExpr->pRight==0 );
+      pExpr->pRight = sqlite3ExprDup(db, pNew->pRight);
+      assert( pExpr->pList==0 );
+      pExpr->pList = sqlite3ExprListDup(db, pNew->pList);
+      pExpr->iTable = pNew->iTable;
+      pExpr->pTab = pNew->pTab;
+      pExpr->iColumn = pNew->iColumn;
+      pExpr->iAgg = pNew->iAgg;
+      sqlite3TokenCopy(db, &pExpr->token, &pNew->token);
+      sqlite3TokenCopy(db, &pExpr->span, &pNew->span);
+      pExpr->pSelect = sqlite3SelectDup(db, pNew->pSelect);
+      pExpr->flags = pNew->flags;
+    }
+  }else{
+    substExpr(db, pExpr->pLeft, iTable, pEList);
+    substExpr(db, pExpr->pRight, iTable, pEList);
+    substSelect(db, pExpr->pSelect, iTable, pEList);
+    substExprList(db, pExpr->pList, iTable, pEList);
+  }
+}
+static void substExprList(
+  sqlite3 *db,         /* Report malloc errors here */
+  ExprList *pList,     /* List to scan and in which to make substitutes */
+  int iTable,          /* Table to be substituted */
+  ExprList *pEList     /* Substitute values */
+){
+  int i;
+  if( pList==0 ) return;
+  for(i=0; i<pList->nExpr; i++){
+    substExpr(db, pList->a[i].pExpr, iTable, pEList);
+  }
+}
+static void substSelect(
+  sqlite3 *db,         /* Report malloc errors here */
+  Select *p,           /* SELECT statement in which to make substitutions */
+  int iTable,          /* Table to be replaced */
+  ExprList *pEList     /* Substitute values */
+){
+  if( !p ) return;
+  substExprList(db, p->pEList, iTable, pEList);
+  substExprList(db, p->pGroupBy, iTable, pEList);
+  substExprList(db, p->pOrderBy, iTable, pEList);
+  substExpr(db, p->pHaving, iTable, pEList);
+  substExpr(db, p->pWhere, iTable, pEList);
+  substSelect(db, p->pPrior, iTable, pEList);
+}
+#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
+
+#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
+/*
+** This routine attempts to flatten subqueries in order to speed
+** execution.  It returns 1 if it makes changes and 0 if no flattening
+** occurs.
+**
+** To understand the concept of flattening, consider the following
+** query:
+**
+**     SELECT a FROM (SELECT x+y AS a FROM t1 WHERE z<100) WHERE a>5
+**
+** The default way of implementing this query is to execute the
+** subquery first and store the results in a temporary table, then
+** run the outer query on that temporary table.  This requires two
+** passes over the data.  Furthermore, because the temporary table
+** has no indices, the WHERE clause on the outer query cannot be
+** optimized.
+**
+** This routine attempts to rewrite queries such as the above into
+** a single flat select, like this:
+**
+**     SELECT x+y AS a FROM t1 WHERE z<100 AND a>5
+**
+** The code generated for this simpification gives the same result
+** but only has to scan the data once.  And because indices might 
+** exist on the table t1, a complete scan of the data might be
+** avoided.
+**
+** Flattening is only attempted if all of the following are true:
+**
+**   (1)  The subquery and the outer query do not both use aggregates.
+**
+**   (2)  The subquery is not an aggregate or the outer query is not a join.
+**
+**   (3)  The subquery is not the right operand of a left outer join, or
+**        the subquery is not itself a join.  (Ticket #306)
+**
+**   (4)  The subquery is not DISTINCT or the outer query is not a join.
+**
+**   (5)  The subquery is not DISTINCT or the outer query does not use
+**        aggregates.
+**
+**   (6)  The subquery does not use aggregates or the outer query is not
+**        DISTINCT.
+**
+**   (7)  The subquery has a FROM clause.
+**
+**   (8)  The subquery does not use LIMIT or the outer query is not a join.
+**
+**   (9)  The subquery does not use LIMIT or the outer query does not use
+**        aggregates.
+**
+**  (10)  The subquery does not use aggregates or the outer query does not
+**        use LIMIT.
+**
+**  (11)  The subquery and the outer query do not both have ORDER BY clauses.
+**
+**  (12)  The subquery is not the right term of a LEFT OUTER JOIN or the
+**        subquery has no WHERE clause.  (added by ticket #350)
+**
+**  (13)  The subquery and outer query do not both use LIMIT
+**
+**  (14)  The subquery does not use OFFSET
+**
+**  (15)  The outer query is not part of a compound select or the
+**        subquery does not have both an ORDER BY and a LIMIT clause.
+**        (See ticket #2339)
+**
+**  (16)  The outer query is not an aggregate or the subquery does
+**        not contain ORDER BY.  (Ticket #2942)  This used to not matter
+**        until we introduced the group_concat() function.  
+**
+**  (17)  The sub-query is not a compound select, or it is a UNION ALL 
+**        compound clause made up entirely of non-aggregate queries, and 
+**        the parent query:
+**
+**          * is not itself part of a compound select,
+**          * is not an aggregate or DISTINCT query, and
+**          * has no other tables or sub-selects in the FROM clause.
+**
+**        The parent and sub-query may contain WHERE clauses. Subject to
+**        rules (11), (13) and (14), they may also contain ORDER BY,
+**        LIMIT and OFFSET clauses.
+**
+**  (18)  If the sub-query is a compound select, then all terms of the
+**        ORDER by clause of the parent must be simple references to 
+**        columns of the sub-query.
+**
+** In this routine, the "p" parameter is a pointer to the outer query.
+** The subquery is p->pSrc->a[iFrom].  isAgg is true if the outer query
+** uses aggregates and subqueryIsAgg is true if the subquery uses aggregates.
+**
+** If flattening is not attempted, this routine is a no-op and returns 0.
+** If flattening is attempted this routine returns 1.
+**
+** All of the expression analysis must occur on both the outer query and
+** the subquery before this routine runs.
+*/
+static int flattenSubquery(
+  Parse *pParse,       /* Parsing context */
+  Select *p,           /* The parent or outer SELECT statement */
+  int iFrom,           /* Index in p->pSrc->a[] of the inner subquery */
+  int isAgg,           /* True if outer SELECT uses aggregate functions */
+  int subqueryIsAgg    /* True if the subquery uses aggregate functions */
+){
+  const char *zSavedAuthContext = pParse->zAuthContext;
+  Select *pParent;
+  Select *pSub;       /* The inner query or "subquery" */
+  Select *pSub1;      /* Pointer to the rightmost select in sub-query */
+  SrcList *pSrc;      /* The FROM clause of the outer query */
+  SrcList *pSubSrc;   /* The FROM clause of the subquery */
+  ExprList *pList;    /* The result set of the outer query */
+  int iParent;        /* VDBE cursor number of the pSub result set temp table */
+  int i;              /* Loop counter */
+  Expr *pWhere;                    /* The WHERE clause */
+  struct SrcList_item *pSubitem;   /* The subquery */
+  sqlite3 *db = pParse->db;
+
+  /* Check to see if flattening is permitted.  Return 0 if not.
+  */
+  if( p==0 ) return 0;
+  pSrc = p->pSrc;
+  assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
+  pSubitem = &pSrc->a[iFrom];
+  iParent = pSubitem->iCursor;
+  pSub = pSubitem->pSelect;
+  assert( pSub!=0 );
+  if( isAgg && subqueryIsAgg ) return 0;                 /* Restriction (1)  */
+  if( subqueryIsAgg && pSrc->nSrc>1 ) return 0;          /* Restriction (2)  */
+  pSubSrc = pSub->pSrc;
+  assert( pSubSrc );
+  /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
+  ** not arbitrary expresssions, we allowed some combining of LIMIT and OFFSET
+  ** because they could be computed at compile-time.  But when LIMIT and OFFSET
+  ** became arbitrary expressions, we were forced to add restrictions (13)
+  ** and (14). */
+  if( pSub->pLimit && p->pLimit ) return 0;              /* Restriction (13) */
+  if( pSub->pOffset ) return 0;                          /* Restriction (14) */
+  if( p->pRightmost && pSub->pLimit && pSub->pOrderBy ){
+    return 0;                                            /* Restriction (15) */
+  }
+  if( pSubSrc->nSrc==0 ) return 0;                       /* Restriction (7)  */
+  if( (pSub->isDistinct || pSub->pLimit) 
+         && (pSrc->nSrc>1 || isAgg) ){          /* Restrictions (4)(5)(8)(9) */
+     return 0;       
+  }
+  if( p->isDistinct && subqueryIsAgg ) return 0;         /* Restriction (6)  */
+  if( (p->disallowOrderBy || p->pOrderBy) && pSub->pOrderBy ){
+     return 0;                                           /* Restriction (11) */
+  }
+  if( isAgg && pSub->pOrderBy ) return 0;                /* Restriction (16) */
+
+  /* Restriction 3:  If the subquery is a join, make sure the subquery is 
+  ** not used as the right operand of an outer join.  Examples of why this
+  ** is not allowed:
+  **
+  **         t1 LEFT OUTER JOIN (t2 JOIN t3)
+  **
+  ** If we flatten the above, we would get
+  **
+  **         (t1 LEFT OUTER JOIN t2) JOIN t3
+  **
+  ** which is not at all the same thing.
+  */
+  if( pSubSrc->nSrc>1 && (pSubitem->jointype & JT_OUTER)!=0 ){
+    return 0;
+  }
+
+  /* Restriction 12:  If the subquery is the right operand of a left outer
+  ** join, make sure the subquery has no WHERE clause.
+  ** An examples of why this is not allowed:
+  **
+  **         t1 LEFT OUTER JOIN (SELECT * FROM t2 WHERE t2.x>0)
+  **
+  ** If we flatten the above, we would get
+  **
+  **         (t1 LEFT OUTER JOIN t2) WHERE t2.x>0
+  **
+  ** But the t2.x>0 test will always fail on a NULL row of t2, which
+  ** effectively converts the OUTER JOIN into an INNER JOIN.
+  */
+  if( (pSubitem->jointype & JT_OUTER)!=0 && pSub->pWhere!=0 ){
+    return 0;
+  }
+
+  /* Restriction 17: If the sub-query is a compound SELECT, then it must
+  ** use only the UNION ALL operator. And none of the simple select queries
+  ** that make up the compound SELECT are allowed to be aggregate or distinct
+  ** queries.
+  */
+  if( pSub->pPrior ){
+    if( p->pPrior || isAgg || p->isDistinct || pSrc->nSrc!=1 ){
+      return 0;
+    }
+    for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){
+      if( pSub1->isAgg || pSub1->isDistinct 
+       || (pSub1->pPrior && pSub1->op!=TK_ALL) 
+       || !pSub1->pSrc || pSub1->pSrc->nSrc!=1
+      ){
+        return 0;
+      }
+    }
+
+    /* Restriction 18. */
+    if( p->pOrderBy ){
+      int ii;
+      for(ii=0; ii<p->pOrderBy->nExpr; ii++){
+        Expr *pExpr = p->pOrderBy->a[ii].pExpr;
+        if( pExpr->op!=TK_COLUMN || pExpr->iTable!=iParent ){ 
+          return 0;
+        }
+      }
+    }
+  }
+
+  pParse->zAuthContext = pSubitem->zName;
+  sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0);
+  pParse->zAuthContext = zSavedAuthContext;
+
+  /* If the sub-query is a compound SELECT statement, then it must be
+  ** a UNION ALL and the parent query must be of the form:
+  **
+  **     SELECT <expr-list> FROM (<sub-query>) <where-clause> 
+  **
+  ** followed by any ORDER BY, LIMIT and/or OFFSET clauses. This block
+  ** creates N copies of the parent query without any ORDER BY, LIMIT or 
+  ** OFFSET clauses and joins them to the left-hand-side of the original
+  ** using UNION ALL operators. In this case N is the number of simple
+  ** select statements in the compound sub-query.
+  */
+  for(pSub=pSub->pPrior; pSub; pSub=pSub->pPrior){
+    Select *pNew;
+    ExprList *pOrderBy = p->pOrderBy;
+    Expr *pLimit = p->pLimit;
+    Expr *pOffset = p->pOffset;
+    Select *pPrior = p->pPrior;
+    p->pOrderBy = 0;
+    p->pSrc = 0;
+    p->pPrior = 0;
+    p->pLimit = 0;
+    pNew = sqlite3SelectDup(db, p);
+    pNew->pPrior = pPrior;
+    p->pPrior = pNew;
+    p->pOrderBy = pOrderBy;
+    p->op = TK_ALL;
+    p->pSrc = pSrc;
+    p->pLimit = pLimit;
+    p->pOffset = pOffset;
+    p->pRightmost = 0;
+    pNew->pRightmost = 0;
+  }
+
+  /* If we reach this point, it means flattening is permitted for the
+  ** iFrom-th entry of the FROM clause in the outer query.
+  */
+  pSub = pSub1 = pSubitem->pSelect;
+  for(pParent=p; pParent; pParent=pParent->pPrior, pSub=pSub->pPrior){
+    int nSubSrc = pSubSrc->nSrc;
+    int jointype = 0;
+    pSubSrc = pSub->pSrc;
+    pSrc = pParent->pSrc;
+
+    /* Move all of the FROM elements of the subquery into the
+    ** the FROM clause of the outer query.  Before doing this, remember
+    ** the cursor number for the original outer query FROM element in
+    ** iParent.  The iParent cursor will never be used.  Subsequent code
+    ** will scan expressions looking for iParent references and replace
+    ** those references with expressions that resolve to the subquery FROM
+    ** elements we are now copying in.
+    */
+    if( pSrc ){
+      pSubitem = &pSrc->a[iFrom];
+      nSubSrc = pSubSrc->nSrc;
+      jointype = pSubitem->jointype;
+      sqlite3DeleteTable(pSubitem->pTab);
+      sqlite3DbFree(db, pSubitem->zDatabase);
+      sqlite3DbFree(db, pSubitem->zName);
+      sqlite3DbFree(db, pSubitem->zAlias);
+      pSubitem->pTab = 0;
+      pSubitem->zDatabase = 0;
+      pSubitem->zName = 0;
+      pSubitem->zAlias = 0;
+    }
+    if( nSubSrc!=1 || !pSrc ){
+      int extra = nSubSrc - 1;
+      for(i=(pSrc?1:0); i<nSubSrc; i++){
+        pSrc = sqlite3SrcListAppend(db, pSrc, 0, 0);
+        if( pSrc==0 ){
+          pParent->pSrc = 0;
+          return 1;
+        }
+      }
+      pParent->pSrc = pSrc;
+      for(i=pSrc->nSrc-1; i-extra>=iFrom; i--){
+        pSrc->a[i] = pSrc->a[i-extra];
+      }
+    }
+    for(i=0; i<nSubSrc; i++){
+      pSrc->a[i+iFrom] = pSubSrc->a[i];
+      memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
+    }
+    pSrc->a[iFrom].jointype = jointype;
+  
+    /* Now begin substituting subquery result set expressions for 
+    ** references to the iParent in the outer query.
+    ** 
+    ** Example:
+    **
+    **   SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b;
+    **   \                     \_____________ subquery __________/          /
+    **    \_____________________ outer query ______________________________/
+    **
+    ** We look at every expression in the outer query and every place we see
+    ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
+    */
+    pList = pParent->pEList;
+    for(i=0; i<pList->nExpr; i++){
+      Expr *pExpr;
+      if( pList->a[i].zName==0 && (pExpr = pList->a[i].pExpr)->span.z!=0 ){
+        pList->a[i].zName = 
+               sqlite3DbStrNDup(db, (char*)pExpr->span.z, pExpr->span.n);
+      }
+    }
+    substExprList(db, pParent->pEList, iParent, pSub->pEList);
+    if( isAgg ){
+      substExprList(db, pParent->pGroupBy, iParent, pSub->pEList);
+      substExpr(db, pParent->pHaving, iParent, pSub->pEList);
+    }
+    if( pSub->pOrderBy ){
+      assert( pParent->pOrderBy==0 );
+      pParent->pOrderBy = pSub->pOrderBy;
+      pSub->pOrderBy = 0;
+    }else if( pParent->pOrderBy ){
+      substExprList(db, pParent->pOrderBy, iParent, pSub->pEList);
+    }
+    if( pSub->pWhere ){
+      pWhere = sqlite3ExprDup(db, pSub->pWhere);
+    }else{
+      pWhere = 0;
+    }
+    if( subqueryIsAgg ){
+      assert( pParent->pHaving==0 );
+      pParent->pHaving = pParent->pWhere;
+      pParent->pWhere = pWhere;
+      substExpr(db, pParent->pHaving, iParent, pSub->pEList);
+      pParent->pHaving = sqlite3ExprAnd(db, pParent->pHaving, 
+                                  sqlite3ExprDup(db, pSub->pHaving));
+      assert( pParent->pGroupBy==0 );
+      pParent->pGroupBy = sqlite3ExprListDup(db, pSub->pGroupBy);
+    }else{
+      substExpr(db, pParent->pWhere, iParent, pSub->pEList);
+      pParent->pWhere = sqlite3ExprAnd(db, pParent->pWhere, pWhere);
+    }
+  
+    /* The flattened query is distinct if either the inner or the
+    ** outer query is distinct. 
+    */
+    pParent->isDistinct = pParent->isDistinct || pSub->isDistinct;
+  
+    /*
+    ** SELECT ... FROM (SELECT ... LIMIT a OFFSET b) LIMIT x OFFSET y;
+    **
+    ** One is tempted to try to add a and b to combine the limits.  But this
+    ** does not work if either limit is negative.
+    */
+    if( pSub->pLimit ){
+      pParent->pLimit = pSub->pLimit;
+      pSub->pLimit = 0;
+    }
+  }
+
+  /* Finially, delete what is left of the subquery and return
+  ** success.
+  */
+  sqlite3SelectDelete(db, pSub1);
+
+  return 1;
+}
+#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
+
+/*
+** Analyze the SELECT statement passed as an argument to see if it
+** is a min() or max() query. Return WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX if 
+** it is, or 0 otherwise. At present, a query is considered to be
+** a min()/max() query if:
+**
+**   1. There is a single object in the FROM clause.
+**
+**   2. There is a single expression in the result set, and it is
+**      either min(x) or max(x), where x is a column reference.
+*/
+static int minMaxQuery(Parse *pParse, Select *p){
+  Expr *pExpr;
+  ExprList *pEList = p->pEList;
+
+  if( pEList->nExpr!=1 ) return WHERE_ORDERBY_NORMAL;
+  pExpr = pEList->a[0].pExpr;
+  pEList = pExpr->pList;
+  if( pExpr->op!=TK_AGG_FUNCTION || pEList==0 || pEList->nExpr!=1 ) return 0;
+  if( pEList->a[0].pExpr->op!=TK_AGG_COLUMN ) return WHERE_ORDERBY_NORMAL;
+  if( pExpr->token.n!=3 ) return WHERE_ORDERBY_NORMAL;
+  if( sqlite3StrNICmp((char*)pExpr->token.z,"min",3)==0 ){
+    return WHERE_ORDERBY_MIN;
+  }else if( sqlite3StrNICmp((char*)pExpr->token.z,"max",3)==0 ){
+    return WHERE_ORDERBY_MAX;
+  }
+  return WHERE_ORDERBY_NORMAL;
+}
+
+/*
+** This routine resolves any names used in the result set of the
+** supplied SELECT statement. If the SELECT statement being resolved
+** is a sub-select, then pOuterNC is a pointer to the NameContext 
+** of the parent SELECT.
+*/
+int sqlite3SelectResolve(
+  Parse *pParse,         /* The parser context */
+  Select *p,             /* The SELECT statement being coded. */
+  NameContext *pOuterNC  /* The outer name context. May be NULL. */
+){
+  ExprList *pEList;          /* Result set. */
+  int i;                     /* For-loop variable used in multiple places */
+  NameContext sNC;           /* Local name-context */
+  ExprList *pGroupBy;        /* The group by clause */
+
+  /* If this routine has run before, return immediately. */
+  if( p->isResolved ){
+    assert( !pOuterNC );
+    return SQLITE_OK;
+  }
+  p->isResolved = 1;
+
+  /* If there have already been errors, do nothing. */
+  if( pParse->nErr>0 ){
+    return SQLITE_ERROR;
+  }
+
+  /* Prepare the select statement. This call will allocate all cursors
+  ** required to handle the tables and subqueries in the FROM clause.
+  */
+  if( prepSelectStmt(pParse, p) ){
+    return SQLITE_ERROR;
+  }
+
+  /* Resolve the expressions in the LIMIT and OFFSET clauses. These
+  ** are not allowed to refer to any names, so pass an empty NameContext.
+  */
+  memset(&sNC, 0, sizeof(sNC));
+  sNC.pParse = pParse;
+  if( sqlite3ExprResolveNames(&sNC, p->pLimit) ||
+      sqlite3ExprResolveNames(&sNC, p->pOffset) ){
+    return SQLITE_ERROR;
+  }
+
+  /* Set up the local name-context to pass to ExprResolveNames() to
+  ** resolve the expression-list.
+  */
+  sNC.allowAgg = 1;
+  sNC.pSrcList = p->pSrc;
+  sNC.pNext = pOuterNC;
+
+  /* Resolve names in the result set. */
+  pEList = p->pEList;
+  if( !pEList ) return SQLITE_ERROR;
+  for(i=0; i<pEList->nExpr; i++){
+    Expr *pX = pEList->a[i].pExpr;
+    if( sqlite3ExprResolveNames(&sNC, pX) ){
+      return SQLITE_ERROR;
+    }
+  }
+
+  /* If there are no aggregate functions in the result-set, and no GROUP BY 
+  ** expression, do not allow aggregates in any of the other expressions.
+  */
+  assert( !p->isAgg );
+  pGroupBy = p->pGroupBy;
+  if( pGroupBy || sNC.hasAgg ){
+    p->isAgg = 1;
+  }else{
+    sNC.allowAgg = 0;
+  }
+
+  /* If a HAVING clause is present, then there must be a GROUP BY clause.
+  */
+  if( p->pHaving && !pGroupBy ){
+    sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING");
+    return SQLITE_ERROR;
+  }
+
+  /* Add the expression list to the name-context before parsing the
+  ** other expressions in the SELECT statement. This is so that
+  ** expressions in the WHERE clause (etc.) can refer to expressions by
+  ** aliases in the result set.
+  **
+  ** Minor point: If this is the case, then the expression will be
+  ** re-evaluated for each reference to it.
+  */
+  sNC.pEList = p->pEList;
+  if( sqlite3ExprResolveNames(&sNC, p->pWhere) ||
+     sqlite3ExprResolveNames(&sNC, p->pHaving) ){
+    return SQLITE_ERROR;
+  }
+  if( p->pPrior==0 ){
+    if( processOrderGroupBy(pParse, p, p->pOrderBy, 1, &sNC.hasAgg) ){
+      return SQLITE_ERROR;
+    }
+  }
+  if( processOrderGroupBy(pParse, p, pGroupBy, 0, &sNC.hasAgg) ){
+    return SQLITE_ERROR;
+  }
+
+  if( pParse->db->mallocFailed ){
+    return SQLITE_NOMEM;
+  }
+
+  /* Make sure the GROUP BY clause does not contain aggregate functions.
+  */
+  if( pGroupBy ){
+    struct ExprList_item *pItem;
+  
+    for(i=0, pItem=pGroupBy->a; i<pGroupBy->nExpr; i++, pItem++){
+      if( ExprHasProperty(pItem->pExpr, EP_Agg) ){
+        sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in "
+            "the GROUP BY clause");
+        return SQLITE_ERROR;
+      }
+    }
+  }
+
+  /* If this is one SELECT of a compound, be sure to resolve names
+  ** in the other SELECTs.
+  */
+  if( p->pPrior ){
+    return sqlite3SelectResolve(pParse, p->pPrior, pOuterNC);
+  }else{
+    return SQLITE_OK;
+  }
+}
+
+/*
+** Reset the aggregate accumulator.
+**
+** The aggregate accumulator is a set of memory cells that hold
+** intermediate results while calculating an aggregate.  This
+** routine simply stores NULLs in all of those memory cells.
+*/
+static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
+  Vdbe *v = pParse->pVdbe;
+  int i;
+  struct AggInfo_func *pFunc;
+  if( pAggInfo->nFunc+pAggInfo->nColumn==0 ){
+    return;
+  }
+  for(i=0; i<pAggInfo->nColumn; i++){
+    sqlite3VdbeAddOp2(v, OP_Null, 0, pAggInfo->aCol[i].iMem);
+  }
+  for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
+    sqlite3VdbeAddOp2(v, OP_Null, 0, pFunc->iMem);
+    if( pFunc->iDistinct>=0 ){
+      Expr *pE = pFunc->pExpr;
+      if( pE->pList==0 || pE->pList->nExpr!=1 ){
+        sqlite3ErrorMsg(pParse, "DISTINCT in aggregate must be followed "
+           "by an expression");
+        pFunc->iDistinct = -1;
+      }else{
+        KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->pList);
+        sqlite3VdbeAddOp4(v, OP_OpenEphemeral, pFunc->iDistinct, 0, 0,
+                          (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
+      }
+    }
+  }
+}
+
+/*
+** Invoke the OP_AggFinalize opcode for every aggregate function
+** in the AggInfo structure.
+*/
+static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){
+  Vdbe *v = pParse->pVdbe;
+  int i;
+  struct AggInfo_func *pF;
+  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
+    ExprList *pList = pF->pExpr->pList;
+    sqlite3VdbeAddOp4(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0, 0,
+                      (void*)pF->pFunc, P4_FUNCDEF);
+  }
+}
+
+/*
+** Update the accumulator memory cells for an aggregate based on
+** the current cursor position.
+*/
+static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
+  Vdbe *v = pParse->pVdbe;
+  int i;
+  struct AggInfo_func *pF;
+  struct AggInfo_col *pC;
+
+  pAggInfo->directMode = 1;
+  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
+    int nArg;
+    int addrNext = 0;
+    int regAgg;
+    ExprList *pList = pF->pExpr->pList;
+    if( pList ){
+      nArg = pList->nExpr;
+      regAgg = sqlite3GetTempRange(pParse, nArg);
+      sqlite3ExprCodeExprList(pParse, pList, regAgg, 0);
+    }else{
+      nArg = 0;
+      regAgg = 0;
+    }
+    if( pF->iDistinct>=0 ){
+      addrNext = sqlite3VdbeMakeLabel(v);
+      assert( nArg==1 );
+      codeDistinct(pParse, pF->iDistinct, addrNext, 1, regAgg);
+    }
+    if( pF->pFunc->needCollSeq ){
+      CollSeq *pColl = 0;
+      struct ExprList_item *pItem;
+      int j;
+      assert( pList!=0 );  /* pList!=0 if pF->pFunc->needCollSeq is true */
+      for(j=0, pItem=pList->a; !pColl && j<nArg; j++, pItem++){
+        pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
+      }
+      if( !pColl ){
+        pColl = pParse->db->pDfltColl;
+      }
+      sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
+    }
+    sqlite3VdbeAddOp4(v, OP_AggStep, 0, regAgg, pF->iMem,
+                      (void*)pF->pFunc, P4_FUNCDEF);
+    sqlite3VdbeChangeP5(v, nArg);
+    sqlite3ReleaseTempRange(pParse, regAgg, nArg);
+    sqlite3ExprCacheAffinityChange(pParse, regAgg, nArg);
+    if( addrNext ){
+      sqlite3VdbeResolveLabel(v, addrNext);
+    }
+  }
+  for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
+    sqlite3ExprCode(pParse, pC->pExpr, pC->iMem);
+  }
+  pAggInfo->directMode = 0;
+}
+
+/*
+** Generate code for the given SELECT statement.
+**
+** The results are distributed in various ways depending on the
+** contents of the SelectDest structure pointed to by argument pDest
+** as follows:
+**
+**     pDest->eDest    Result
+**     ------------    -------------------------------------------
+**     SRT_Callback    Invoke the callback for each row of the result.
+**
+**     SRT_Mem         Store first result in memory cell pDest->iParm
+**
+**     SRT_Set         Store results as keys of table pDest->iParm. 
+**                     Apply the affinity pDest->affinity before storing them.
+**
+**     SRT_Union       Store results as a key in a temporary table pDest->iParm.
+**
+**     SRT_Except      Remove results from the temporary table pDest->iParm.
+**
+**     SRT_Table       Store results in temporary table pDest->iParm
+**
+**     SRT_EphemTab    Create an temporary table pDest->iParm and store
+**                     the result there. The cursor is left open after
+**                     returning.
+**
+**     SRT_Coroutine   Invoke a co-routine to compute a single row of 
+**                     the result
+**
+**     SRT_Exists      Store a 1 in memory cell pDest->iParm if the result
+**                     set is not empty.
+**
+**     SRT_Discard     Throw the results away.
+**
+** See the selectInnerLoop() function for a canonical listing of the 
+** allowed values of eDest and their meanings.
+**
+** This routine returns the number of errors.  If any errors are
+** encountered, then an appropriate error message is left in
+** pParse->zErrMsg.
+**
+** This routine does NOT free the Select structure passed in.  The
+** calling function needs to do that.
+**
+** The pParent, parentTab, and *pParentAgg fields are filled in if this
+** SELECT is a subquery.  This routine may try to combine this SELECT
+** with its parent to form a single flat query.  In so doing, it might
+** change the parent query from a non-aggregate to an aggregate query.
+** For that reason, the pParentAgg flag is passed as a pointer, so it
+** can be changed.
+**
+** Example 1:   The meaning of the pParent parameter.
+**
+**    SELECT * FROM t1 JOIN (SELECT x, count(*) FROM t2) JOIN t3;
+**    \                      \_______ subquery _______/        /
+**     \                                                      /
+**      \____________________ outer query ___________________/
+**
+** This routine is called for the outer query first.   For that call,
+** pParent will be NULL.  During the processing of the outer query, this 
+** routine is called recursively to handle the subquery.  For the recursive
+** call, pParent will point to the outer query.  Because the subquery is
+** the second element in a three-way join, the parentTab parameter will
+** be 1 (the 2nd value of a 0-indexed array.)
+*/
+int sqlite3Select(
+  Parse *pParse,         /* The parser context */
+  Select *p,             /* The SELECT statement being coded. */
+  SelectDest *pDest,     /* What to do with the query results */
+  Select *pParent,       /* Another SELECT for which this is a sub-query */
+  int parentTab,         /* Index in pParent->pSrc of this query */
+  int *pParentAgg        /* True if pParent uses aggregate functions */
+){
+  int i, j;              /* Loop counters */
+  WhereInfo *pWInfo;     /* Return from sqlite3WhereBegin() */
+  Vdbe *v;               /* The virtual machine under construction */
+  int isAgg;             /* True for select lists like "count(*)" */
+  ExprList *pEList;      /* List of columns to extract. */
+  SrcList *pTabList;     /* List of tables to select from */
+  Expr *pWhere;          /* The WHERE clause.  May be NULL */
+  ExprList *pOrderBy;    /* The ORDER BY clause.  May be NULL */
+  ExprList *pGroupBy;    /* The GROUP BY clause.  May be NULL */
+  Expr *pHaving;         /* The HAVING clause.  May be NULL */
+  int isDistinct;        /* True if the DISTINCT keyword is present */
+  int distinct;          /* Table to use for the distinct set */
+  int rc = 1;            /* Value to return from this function */
+  int addrSortIndex;     /* Address of an OP_OpenEphemeral instruction */
+  AggInfo sAggInfo;      /* Information used by aggregate queries */
+  int iEnd;              /* Address of the end of the query */
+  sqlite3 *db;           /* The database connection */
+
+  db = pParse->db;
+  if( p==0 || db->mallocFailed || pParse->nErr ){
+    return 1;
+  }
+  if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;
+  memset(&sAggInfo, 0, sizeof(sAggInfo));
+
+  pOrderBy = p->pOrderBy;
+  if( IgnorableOrderby(pDest) ){
+    p->pOrderBy = 0;
+
+    /* In these cases the DISTINCT operator makes no difference to the
+    ** results, so remove it if it were specified.
+    */
+    assert(pDest->eDest==SRT_Exists || pDest->eDest==SRT_Union || 
+           pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard);
+    p->isDistinct = 0;
+  }
+  if( sqlite3SelectResolve(pParse, p, 0) ){
+    goto select_end;
+  }
+  p->pOrderBy = pOrderBy;
+
+
+  /* Make local copies of the parameters for this query.
+  */
+  pTabList = p->pSrc;
+  isAgg = p->isAgg;
+  pEList = p->pEList;
+  if( pEList==0 ) goto select_end;
+
+  /* 
+  ** Do not even attempt to generate any code if we have already seen
+  ** errors before this routine starts.
+  */
+  if( pParse->nErr>0 ) goto select_end;
+
+  /* ORDER BY is ignored for some destinations.
+  */
+  if( IgnorableOrderby(pDest) ){
+    pOrderBy = 0;
+  }
+
+  /* Begin generating code.
+  */
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 ) goto select_end;
+
+  /* Generate code for all sub-queries in the FROM clause
+  */
+#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
+  for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
+    struct SrcList_item *pItem = &pTabList->a[i];
+    SelectDest dest;
+    Select *pSub = pItem->pSelect;
+    int isAggSub;
+    char *zName = pItem->zName;
+
+    if( pSub==0 || pItem->isPopulated ) continue;
+    if( zName!=0 ){   /* An sql view */
+      const char *zSavedAuthContext = pParse->zAuthContext;
+      pParse->zAuthContext = zName;
+      rc = sqlite3SelectResolve(pParse, pSub, 0);
+      pParse->zAuthContext = zSavedAuthContext;
+      if( rc ){
+        goto select_end;
+      }
+    }
+
+    /* Increment Parse.nHeight by the height of the largest expression
+    ** tree refered to by this, the parent select. The child select
+    ** may contain expression trees of at most
+    ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
+    ** more conservative than necessary, but much easier than enforcing
+    ** an exact limit.
+    */
+    pParse->nHeight += sqlite3SelectExprHeight(p);
+
+    /* Check to see if the subquery can be absorbed into the parent. */
+    isAggSub = pSub->isAgg;
+    if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){
+      if( isAggSub ){
+        p->isAgg = isAgg = 1;
+      }
+      i = -1;
+    }else{
+      sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
+      sqlite3Select(pParse, pSub, &dest, p, i, &isAgg);
+    }
+    if( pParse->nErr || db->mallocFailed ){
+      goto select_end;
+    }
+    pParse->nHeight -= sqlite3SelectExprHeight(p);
+    pTabList = p->pSrc;
+    if( !IgnorableOrderby(pDest) ){
+      pOrderBy = p->pOrderBy;
+    }
+  }
+  pEList = p->pEList;
+#endif
+  pWhere = p->pWhere;
+  pGroupBy = p->pGroupBy;
+  pHaving = p->pHaving;
+  isDistinct = p->isDistinct;
+
+#ifndef SQLITE_OMIT_COMPOUND_SELECT
+  /* If there is are a sequence of queries, do the earlier ones first.
+  */
+  if( p->pPrior ){
+    if( p->pRightmost==0 ){
+      Select *pLoop, *pRight = 0;
+      int cnt = 0;
+      int mxSelect;
+      for(pLoop=p; pLoop; pLoop=pLoop->pPrior, cnt++){
+        pLoop->pRightmost = p;
+        pLoop->pNext = pRight;
+        pRight = pLoop;
+      }
+      mxSelect = db->aLimit[SQLITE_LIMIT_COMPOUND_SELECT];
+      if( mxSelect && cnt>mxSelect ){
+        sqlite3ErrorMsg(pParse, "too many terms in compound SELECT");
+        return 1;
+      }
+    }
+    return multiSelect(pParse, p, pDest);
+  }
+#endif
+
+  /* If writing to memory or generating a set
+  ** only a single column may be output.
+  */
+#ifndef SQLITE_OMIT_SUBQUERY
+  if( checkForMultiColumnSelectError(pParse, pDest, pEList->nExpr) ){
+    goto select_end;
+  }
+#endif
+
+  /* If possible, rewrite the query to use GROUP BY instead of DISTINCT.
+  ** GROUP BY may use an index, DISTINCT never does.
+  */
+  if( p->isDistinct && !p->isAgg && !p->pGroupBy ){
+    p->pGroupBy = sqlite3ExprListDup(db, p->pEList);
+    pGroupBy = p->pGroupBy;
+    p->isDistinct = 0;
+    isDistinct = 0;
+  }
+
+  /* If there is an ORDER BY clause, then this sorting
+  ** index might end up being unused if the data can be 
+  ** extracted in pre-sorted order.  If that is the case, then the
+  ** OP_OpenEphemeral instruction will be changed to an OP_Noop once
+  ** we figure out that the sorting index is not needed.  The addrSortIndex
+  ** variable is used to facilitate that change.
+  */
+  if( pOrderBy ){
+    KeyInfo *pKeyInfo;
+    pKeyInfo = keyInfoFromExprList(pParse, pOrderBy);
+    pOrderBy->iECursor = pParse->nTab++;
+    p->addrOpenEphm[2] = addrSortIndex =
+      sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
+                           pOrderBy->iECursor, pOrderBy->nExpr+2, 0,
+                           (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
+  }else{
+    addrSortIndex = -1;
+  }
+
+  /* If the output is destined for a temporary table, open that table.
+  */
+  if( pDest->eDest==SRT_EphemTab ){
+    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iParm, pEList->nExpr);
+  }
+
+  /* Set the limiter.
+  */
+  iEnd = sqlite3VdbeMakeLabel(v);
+  computeLimitRegisters(pParse, p, iEnd);
+
+  /* Open a virtual index to use for the distinct set.
+  */
+  if( isDistinct ){
+    KeyInfo *pKeyInfo;
+    assert( isAgg || pGroupBy );
+    distinct = pParse->nTab++;
+    pKeyInfo = keyInfoFromExprList(pParse, p->pEList);
+    sqlite3VdbeAddOp4(v, OP_OpenEphemeral, distinct, 0, 0,
+                        (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
+  }else{
+    distinct = -1;
+  }
+
+  /* Aggregate and non-aggregate queries are handled differently */
+  if( !isAgg && pGroupBy==0 ){
+    /* This case is for non-aggregate queries
+    ** Begin the database scan
+    */
+    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pOrderBy, 0);
+    if( pWInfo==0 ) goto select_end;
+
+    /* If sorting index that was created by a prior OP_OpenEphemeral 
+    ** instruction ended up not being needed, then change the OP_OpenEphemeral
+    ** into an OP_Noop.
+    */
+    if( addrSortIndex>=0 && pOrderBy==0 ){
+      sqlite3VdbeChangeToNoop(v, addrSortIndex, 1);
+      p->addrOpenEphm[2] = -1;
+    }
+
+    /* Use the standard inner loop
+    */
+    assert(!isDistinct);
+    selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, -1, pDest,
+                    pWInfo->iContinue, pWInfo->iBreak);
+
+    /* End the database scan loop.
+    */
+    sqlite3WhereEnd(pWInfo);
+  }else{
+    /* This is the processing for aggregate queries */
+    NameContext sNC;    /* Name context for processing aggregate information */
+    int iAMem;          /* First Mem address for storing current GROUP BY */
+    int iBMem;          /* First Mem address for previous GROUP BY */
+    int iUseFlag;       /* Mem address holding flag indicating that at least
+                        ** one row of the input to the aggregator has been
+                        ** processed */
+    int iAbortFlag;     /* Mem address which causes query abort if positive */
+    int groupBySort;    /* Rows come from source in GROUP BY order */
+
+
+    /* The following variables hold addresses or labels for parts of the
+    ** virtual machine program we are putting together */
+    int addrOutputRow;      /* Start of subroutine that outputs a result row */
+    int regOutputRow;       /* Return address register for output subroutine */
+    int addrSetAbort;       /* Set the abort flag and return */
+    int addrInitializeLoop; /* Start of code that initializes the input loop */
+    int addrTopOfLoop;      /* Top of the input loop */
+    int addrEnd;            /* End of all processing */
+    int addrSortingIdx;     /* The OP_OpenEphemeral for the sorting index */
+    int addrReset;          /* Subroutine for resetting the accumulator */
+    int regReset;           /* Return address register for reset subroutine */
+
+    addrEnd = sqlite3VdbeMakeLabel(v);
+
+    /* Convert TK_COLUMN nodes into TK_AGG_COLUMN and make entries in
+    ** sAggInfo for all TK_AGG_FUNCTION nodes in expressions of the
+    ** SELECT statement.
+    */
+    memset(&sNC, 0, sizeof(sNC));
+    sNC.pParse = pParse;
+    sNC.pSrcList = pTabList;
+    sNC.pAggInfo = &sAggInfo;
+    sAggInfo.nSortingColumn = pGroupBy ? pGroupBy->nExpr+1 : 0;
+    sAggInfo.pGroupBy = pGroupBy;
+    sqlite3ExprAnalyzeAggList(&sNC, pEList);
+    sqlite3ExprAnalyzeAggList(&sNC, pOrderBy);
+    if( pHaving ){
+      sqlite3ExprAnalyzeAggregates(&sNC, pHaving);
+    }
+    sAggInfo.nAccumulator = sAggInfo.nColumn;
+    for(i=0; i<sAggInfo.nFunc; i++){
+      sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->pList);
+    }
+    if( db->mallocFailed ) goto select_end;
+
+    /* Processing for aggregates with GROUP BY is very different and
+    ** much more complex than aggregates without a GROUP BY.
+    */
+    if( pGroupBy ){
+      KeyInfo *pKeyInfo;  /* Keying information for the group by clause */
+      int j1;
+
+      /* Create labels that we will be needing
+      */
+      addrInitializeLoop = sqlite3VdbeMakeLabel(v);
+
+      /* If there is a GROUP BY clause we might need a sorting index to
+      ** implement it.  Allocate that sorting index now.  If it turns out
+      ** that we do not need it after all, the OpenEphemeral instruction
+      ** will be converted into a Noop.  
+      */
+      sAggInfo.sortingIdx = pParse->nTab++;
+      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy);
+      addrSortingIdx = sqlite3VdbeAddOp4(v, OP_OpenEphemeral, 
+          sAggInfo.sortingIdx, sAggInfo.nSortingColumn, 
+          0, (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
+
+      /* Initialize memory locations used by GROUP BY aggregate processing
+      */
+      iUseFlag = ++pParse->nMem;
+      iAbortFlag = ++pParse->nMem;
+      iAMem = pParse->nMem + 1;
+      pParse->nMem += pGroupBy->nExpr;
+      iBMem = pParse->nMem + 1;
+      pParse->nMem += pGroupBy->nExpr;
+      sqlite3VdbeAddOp2(v, OP_Integer, 0, iAbortFlag);
+      VdbeComment((v, "clear abort flag"));
+      sqlite3VdbeAddOp2(v, OP_Integer, 0, iUseFlag);
+      VdbeComment((v, "indicate accumulator empty"));
+      sqlite3VdbeAddOp2(v, OP_Goto, 0, addrInitializeLoop);
+
+      /* Generate a subroutine that outputs a single row of the result
+      ** set.  This subroutine first looks at the iUseFlag.  If iUseFlag
+      ** is less than or equal to zero, the subroutine is a no-op.  If
+      ** the processing calls for the query to abort, this subroutine
+      ** increments the iAbortFlag memory location before returning in
+      ** order to signal the caller to abort.
+      */
+      addrSetAbort = sqlite3VdbeCurrentAddr(v);
+      sqlite3VdbeAddOp2(v, OP_Integer, 1, iAbortFlag);
+      VdbeComment((v, "set abort flag"));
+      regOutputRow = ++pParse->nMem;
+      sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
+      addrOutputRow = sqlite3VdbeCurrentAddr(v);
+      sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2);
+      VdbeComment((v, "Groupby result generator entry point"));
+      sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
+      finalizeAggFunctions(pParse, &sAggInfo);
+      if( pHaving ){
+        sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, SQLITE_JUMPIFNULL);
+      }
+      selectInnerLoop(pParse, p, p->pEList, 0, 0, pOrderBy,
+                      distinct, pDest,
+                      addrOutputRow+1, addrSetAbort);
+      sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
+      VdbeComment((v, "end groupby result generator"));
+
+      /* Generate a subroutine that will reset the group-by accumulator
+      */
+      addrReset = sqlite3VdbeCurrentAddr(v);
+      regReset = ++pParse->nMem;
+      resetAccumulator(pParse, &sAggInfo);
+      sqlite3VdbeAddOp1(v, OP_Return, regReset);
+
+      /* Begin a loop that will extract all source rows in GROUP BY order.
+      ** This might involve two separate loops with an OP_Sort in between, or
+      ** it might be a single loop that uses an index to extract information
+      ** in the right order to begin with.
+      */
+      sqlite3VdbeResolveLabel(v, addrInitializeLoop);
+      sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
+      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pGroupBy, 0);
+      if( pWInfo==0 ) goto select_end;
+      if( pGroupBy==0 ){
+        /* The optimizer is able to deliver rows in group by order so
+        ** we do not have to sort.  The OP_OpenEphemeral table will be
+        ** cancelled later because we still need to use the pKeyInfo
+        */
+        pGroupBy = p->pGroupBy;
+        groupBySort = 0;
+      }else{
+        /* Rows are coming out in undetermined order.  We have to push
+        ** each row into a sorting index, terminate the first loop,
+        ** then loop over the sorting index in order to get the output
+        ** in sorted order
+        */
+        int regBase;
+        int regRecord;
+        int nCol;
+        int nGroupBy;
+
+        groupBySort = 1;
+        nGroupBy = pGroupBy->nExpr;
+        nCol = nGroupBy + 1;
+        j = nGroupBy+1;
+        for(i=0; i<sAggInfo.nColumn; i++){
+          if( sAggInfo.aCol[i].iSorterColumn>=j ){
+            nCol++;
+            j++;
+          }
+        }
+        regBase = sqlite3GetTempRange(pParse, nCol);
+        sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0);
+        sqlite3VdbeAddOp2(v, OP_Sequence, sAggInfo.sortingIdx,regBase+nGroupBy);
+        j = nGroupBy+1;
+        for(i=0; i<sAggInfo.nColumn; i++){
+          struct AggInfo_col *pCol = &sAggInfo.aCol[i];
+          if( pCol->iSorterColumn>=j ){
+            int r1 = j + regBase;
+#ifndef NDEBUG
+            int r2 = 
+#endif
+                     sqlite3ExprCodeGetColumn(pParse, 
+                               pCol->pTab, pCol->iColumn, pCol->iTable, r1, 0);
+            j++;
+
+            /* sAggInfo.aCol[] only contains one entry per column.  So
+            ** The reference to pCol->iColumn,pCol->iTable must have been
+            ** the first reference to that column.  Hence, 
+            ** sqliteExprCodeGetColumn is guaranteed to put the result in
+            ** the column requested. 
+            */
+            assert( r1==r2 );
+          }
+        }
+        regRecord = sqlite3GetTempReg(pParse);
+        sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);
+        sqlite3VdbeAddOp2(v, OP_IdxInsert, sAggInfo.sortingIdx, regRecord);
+        sqlite3ReleaseTempReg(pParse, regRecord);
+        sqlite3ReleaseTempRange(pParse, regBase, nCol);
+        sqlite3WhereEnd(pWInfo);
+        sqlite3VdbeAddOp2(v, OP_Sort, sAggInfo.sortingIdx, addrEnd);
+        VdbeComment((v, "GROUP BY sort"));
+        sAggInfo.useSortingIdx = 1;
+      }
+
+      /* Evaluate the current GROUP BY terms and store in b0, b1, b2...
+      ** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)
+      ** Then compare the current GROUP BY terms against the GROUP BY terms
+      ** from the previous row currently stored in a0, a1, a2...
+      */
+      addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
+      for(j=0; j<pGroupBy->nExpr; j++){
+        if( groupBySort ){
+          sqlite3VdbeAddOp3(v, OP_Column, sAggInfo.sortingIdx, j, iBMem+j);
+        }else{
+          sAggInfo.directMode = 1;
+          sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr, iBMem+j);
+        }
+      }
+      sqlite3VdbeAddOp4(v, OP_Compare, iAMem, iBMem, pGroupBy->nExpr,
+                          (char*)pKeyInfo, P4_KEYINFO);
+      j1 = sqlite3VdbeCurrentAddr(v);
+      sqlite3VdbeAddOp3(v, OP_Jump, j1+1, 0, j1+1);
+
+      /* Generate code that runs whenever the GROUP BY changes.
+      ** Changes in the GROUP BY are detected by the previous code
+      ** block.  If there were no changes, this block is skipped.
+      **
+      ** This code copies current group by terms in b0,b1,b2,...
+      ** over to a0,a1,a2.  It then calls the output subroutine
+      ** and resets the aggregate accumulator registers in preparation
+      ** for the next GROUP BY batch.
+      */
+      sqlite3ExprCodeMove(pParse, iBMem, iAMem, pGroupBy->nExpr);
+      sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
+      VdbeComment((v, "output one row"));
+      sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd);
+      VdbeComment((v, "check abort flag"));
+      sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
+      VdbeComment((v, "reset accumulator"));
+
+      /* Update the aggregate accumulators based on the content of
+      ** the current row
+      */
+      sqlite3VdbeJumpHere(v, j1);
+      updateAccumulator(pParse, &sAggInfo);
+      sqlite3VdbeAddOp2(v, OP_Integer, 1, iUseFlag);
+      VdbeComment((v, "indicate data in accumulator"));
+
+      /* End of the loop
+      */
+      if( groupBySort ){
+        sqlite3VdbeAddOp2(v, OP_Next, sAggInfo.sortingIdx, addrTopOfLoop);
+      }else{
+        sqlite3WhereEnd(pWInfo);
+        sqlite3VdbeChangeToNoop(v, addrSortingIdx, 1);
+      }
+
+      /* Output the final row of result
+      */
+      sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
+      VdbeComment((v, "output final row"));
+      
+    } /* endif pGroupBy */
+    else {
+      ExprList *pMinMax = 0;
+      ExprList *pDel = 0;
+      u8 flag;
+
+      /* Check if the query is of one of the following forms:
+      **
+      **   SELECT min(x) FROM ...
+      **   SELECT max(x) FROM ...
+      **
+      ** If it is, then ask the code in where.c to attempt to sort results
+      ** as if there was an "ORDER ON x" or "ORDER ON x DESC" clause. 
+      ** If where.c is able to produce results sorted in this order, then
+      ** add vdbe code to break out of the processing loop after the 
+      ** first iteration (since the first iteration of the loop is 
+      ** guaranteed to operate on the row with the minimum or maximum 
+      ** value of x, the only row required).
+      **
+      ** A special flag must be passed to sqlite3WhereBegin() to slightly
+      ** modify behaviour as follows:
+      **
+      **   + If the query is a "SELECT min(x)", then the loop coded by
+      **     where.c should not iterate over any values with a NULL value
+      **     for x.
+      **
+      **   + The optimizer code in where.c (the thing that decides which
+      **     index or indices to use) should place a different priority on 
+      **     satisfying the 'ORDER BY' clause than it does in other cases.
+      **     Refer to code and comments in where.c for details.
+      */
+      flag = minMaxQuery(pParse, p);
+      if( flag ){
+        pDel = pMinMax = sqlite3ExprListDup(db, p->pEList->a[0].pExpr->pList);
+        if( pMinMax && !db->mallocFailed ){
+          pMinMax->a[0].sortOrder = flag!=WHERE_ORDERBY_MIN;
+          pMinMax->a[0].pExpr->op = TK_COLUMN;
+        }
+      }
+
+      /* This case runs if the aggregate has no GROUP BY clause.  The
+      ** processing is much simpler since there is only a single row
+      ** of output.
+      */
+      resetAccumulator(pParse, &sAggInfo);
+      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pMinMax, flag);
+      if( pWInfo==0 ){
+        sqlite3ExprListDelete(db, pDel);
+        goto select_end;
+      }
+      updateAccumulator(pParse, &sAggInfo);
+      if( !pMinMax && flag ){
+        sqlite3VdbeAddOp2(v, OP_Goto, 0, pWInfo->iBreak);
+        VdbeComment((v, "%s() by index",(flag==WHERE_ORDERBY_MIN?"min":"max")));
+      }
+      sqlite3WhereEnd(pWInfo);
+      finalizeAggFunctions(pParse, &sAggInfo);
+      pOrderBy = 0;
+      if( pHaving ){
+        sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL);
+      }
+      selectInnerLoop(pParse, p, p->pEList, 0, 0, 0, -1, 
+                      pDest, addrEnd, addrEnd);
+
+      sqlite3ExprListDelete(db, pDel);
+    }
+    sqlite3VdbeResolveLabel(v, addrEnd);
+    
+  } /* endif aggregate query */
+
+  /* If there is an ORDER BY clause, then we need to sort the results
+  ** and send them to the callback one by one.
+  */
+  if( pOrderBy ){
+    generateSortTail(pParse, p, v, pEList->nExpr, pDest);
+  }
+
+#ifndef SQLITE_OMIT_SUBQUERY
+  /* If this was a subquery, we have now converted the subquery into a
+  ** temporary table.  So set the SrcList_item.isPopulated flag to prevent
+  ** this subquery from being evaluated again and to force the use of
+  ** the temporary table.
+  */
+  if( pParent ){
+    assert( pParent->pSrc->nSrc>parentTab );
+    assert( pParent->pSrc->a[parentTab].pSelect==p );
+    pParent->pSrc->a[parentTab].isPopulated = 1;
+  }
+#endif
+
+  /* Jump here to skip this query
+  */
+  sqlite3VdbeResolveLabel(v, iEnd);
+
+  /* The SELECT was successfully coded.   Set the return code to 0
+  ** to indicate no errors.
+  */
+  rc = 0;
+
+  /* Control jumps to here if an error is encountered above, or upon
+  ** successful coding of the SELECT.
+  */
+select_end:
+
+  /* Identify column names if we will be using them in a callback.  This
+  ** step is skipped if the output is going to some other destination.
+  */
+  if( rc==SQLITE_OK && pDest->eDest==SRT_Callback ){
+    generateColumnNames(pParse, pTabList, pEList);
+  }
+
+  sqlite3DbFree(db, sAggInfo.aCol);
+  sqlite3DbFree(db, sAggInfo.aFunc);
+  return rc;
+}
+
+#if defined(SQLITE_DEBUG)
+/*
+*******************************************************************************
+** The following code is used for testing and debugging only.  The code
+** that follows does not appear in normal builds.
+**
+** These routines are used to print out the content of all or part of a 
+** parse structures such as Select or Expr.  Such printouts are useful
+** for helping to understand what is happening inside the code generator
+** during the execution of complex SELECT statements.
+**
+** These routine are not called anywhere from within the normal
+** code base.  Then are intended to be called from within the debugger
+** or from temporary "printf" statements inserted for debugging.
+*/
+void sqlite3PrintExpr(Expr *p){
+  if( p->token.z && p->token.n>0 ){
+    sqlite3DebugPrintf("(%.*s", p->token.n, p->token.z);
+  }else{
+    sqlite3DebugPrintf("(%d", p->op);
+  }
+  if( p->pLeft ){
+    sqlite3DebugPrintf(" ");
+    sqlite3PrintExpr(p->pLeft);
+  }
+  if( p->pRight ){
+    sqlite3DebugPrintf(" ");
+    sqlite3PrintExpr(p->pRight);
+  }
+  sqlite3DebugPrintf(")");
+}
+void sqlite3PrintExprList(ExprList *pList){
+  int i;
+  for(i=0; i<pList->nExpr; i++){
+    sqlite3PrintExpr(pList->a[i].pExpr);
+    if( i<pList->nExpr-1 ){
+      sqlite3DebugPrintf(", ");
+    }
+  }
+}
+void sqlite3PrintSelect(Select *p, int indent){
+  sqlite3DebugPrintf("%*sSELECT(%p) ", indent, "", p);
+  sqlite3PrintExprList(p->pEList);
+  sqlite3DebugPrintf("\n");
+  if( p->pSrc ){
+    char *zPrefix;
+    int i;
+    zPrefix = "FROM";
+    for(i=0; i<p->pSrc->nSrc; i++){
+      struct SrcList_item *pItem = &p->pSrc->a[i];
+      sqlite3DebugPrintf("%*s ", indent+6, zPrefix);
+      zPrefix = "";
+      if( pItem->pSelect ){
+        sqlite3DebugPrintf("(\n");
+        sqlite3PrintSelect(pItem->pSelect, indent+10);
+        sqlite3DebugPrintf("%*s)", indent+8, "");
+      }else if( pItem->zName ){
+        sqlite3DebugPrintf("%s", pItem->zName);
+      }
+      if( pItem->pTab ){
+        sqlite3DebugPrintf("(table: %s)", pItem->pTab->zName);
+      }
+      if( pItem->zAlias ){
+        sqlite3DebugPrintf(" AS %s", pItem->zAlias);
+      }
+      if( i<p->pSrc->nSrc-1 ){
+        sqlite3DebugPrintf(",");
+      }
+      sqlite3DebugPrintf("\n");
+    }
+  }
+  if( p->pWhere ){
+    sqlite3DebugPrintf("%*s WHERE ", indent, "");
+    sqlite3PrintExpr(p->pWhere);
+    sqlite3DebugPrintf("\n");
+  }
+  if( p->pGroupBy ){
+    sqlite3DebugPrintf("%*s GROUP BY ", indent, "");
+    sqlite3PrintExprList(p->pGroupBy);
+    sqlite3DebugPrintf("\n");
+  }
+  if( p->pHaving ){
+    sqlite3DebugPrintf("%*s HAVING ", indent, "");
+    sqlite3PrintExpr(p->pHaving);
+    sqlite3DebugPrintf("\n");
+  }
+  if( p->pOrderBy ){
+    sqlite3DebugPrintf("%*s ORDER BY ", indent, "");
+    sqlite3PrintExprList(p->pOrderBy);
+    sqlite3DebugPrintf("\n");
+  }
+}
+/* End of the structure debug printing code
+*****************************************************************************/
+#endif /* defined(SQLITE_TEST) || defined(SQLITE_DEBUG) */
diff --git a/third_party/sqlite/src/shell.c b/third_party/sqlite/src/shell.c
new file mode 100755
index 0000000..77ec143
--- /dev/null
+++ b/third_party/sqlite/src/shell.c
@@ -0,0 +1,2106 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code to implement the "sqlite" command line
+** utility for accessing SQLite databases.
+**
+** $Id: shell.c,v 1.184 2008/07/11 17:23:25 drh Exp $
+*/
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <assert.h>
+#include "sqlite3.h"
+#include <ctype.h>
+#include <stdarg.h>
+
+#if !defined(_WIN32) && !defined(WIN32) && !defined(__OS2__)
+# include <signal.h>
+# include <pwd.h>
+# include <unistd.h>
+# include <sys/types.h>
+#endif
+
+#ifdef __OS2__
+# include <unistd.h>
+#endif
+
+#if defined(HAVE_READLINE) && HAVE_READLINE==1
+# include <readline/readline.h>
+# include <readline/history.h>
+#else
+# define readline(p) local_getline(p,stdin)
+# define add_history(X)
+# define read_history(X)
+# define write_history(X)
+# define stifle_history(X)
+#endif
+
+#if defined(_WIN32) || defined(WIN32)
+# include <io.h>
+#else
+/* Make sure isatty() has a prototype.
+*/
+extern int isatty();
+#endif
+
+#if defined(_WIN32_WCE)
+/* Windows CE (arm-wince-mingw32ce-gcc) does not provide isatty()
+ * thus we always assume that we have a console. That can be
+ * overridden with the -batch command line option.
+ */
+#define isatty(x) 1
+#endif
+
+#if !defined(_WIN32) && !defined(WIN32) && !defined(__OS2__)
+#include <sys/time.h>
+#include <sys/resource.h>
+
+/* Saved resource information for the beginning of an operation */
+static struct rusage sBegin;
+
+/* True if the timer is enabled */
+static int enableTimer = 0;
+
+/*
+** Begin timing an operation
+*/
+static void beginTimer(void){
+  if( enableTimer ){
+    getrusage(RUSAGE_SELF, &sBegin);
+  }
+}
+
+/* Return the difference of two time_structs in seconds */
+static double timeDiff(struct timeval *pStart, struct timeval *pEnd){
+  return (pEnd->tv_usec - pStart->tv_usec)*0.000001 + 
+         (double)(pEnd->tv_sec - pStart->tv_sec);
+}
+
+/*
+** Print the timing results.
+*/
+static void endTimer(void){
+  if( enableTimer ){
+    struct rusage sEnd;
+    getrusage(RUSAGE_SELF, &sEnd);
+    printf("CPU Time: user %f sys %f\n",
+       timeDiff(&sBegin.ru_utime, &sEnd.ru_utime),
+       timeDiff(&sBegin.ru_stime, &sEnd.ru_stime));
+  }
+}
+#define BEGIN_TIMER beginTimer()
+#define END_TIMER endTimer()
+#define HAS_TIMER 1
+#else
+#define BEGIN_TIMER 
+#define END_TIMER
+#define HAS_TIMER 0
+#endif
+
+
+/*
+** If the following flag is set, then command execution stops
+** at an error if we are not interactive.
+*/
+static int bail_on_error = 0;
+
+/*
+** Threat stdin as an interactive input if the following variable
+** is true.  Otherwise, assume stdin is connected to a file or pipe.
+*/
+static int stdin_is_interactive = 1;
+
+/*
+** The following is the open SQLite database.  We make a pointer
+** to this database a static variable so that it can be accessed
+** by the SIGINT handler to interrupt database processing.
+*/
+static sqlite3 *db = 0;
+
+/*
+** True if an interrupt (Control-C) has been received.
+*/
+static volatile int seenInterrupt = 0;
+
+/*
+** This is the name of our program. It is set in main(), used
+** in a number of other places, mostly for error messages.
+*/
+static char *Argv0;
+
+/*
+** Prompt strings. Initialized in main. Settable with
+**   .prompt main continue
+*/
+static char mainPrompt[20];     /* First line prompt. default: "sqlite> "*/
+static char continuePrompt[20]; /* Continuation prompt. default: "   ...> " */
+
+/*
+** Write I/O traces to the following stream.
+*/
+#ifdef SQLITE_ENABLE_IOTRACE
+static FILE *iotrace = 0;
+#endif
+
+/*
+** This routine works like printf in that its first argument is a
+** format string and subsequent arguments are values to be substituted
+** in place of % fields.  The result of formatting this string
+** is written to iotrace.
+*/
+#ifdef SQLITE_ENABLE_IOTRACE
+static void iotracePrintf(const char *zFormat, ...){
+  va_list ap;
+  char *z;
+  if( iotrace==0 ) return;
+  va_start(ap, zFormat);
+  z = sqlite3_vmprintf(zFormat, ap);
+  va_end(ap);
+  fprintf(iotrace, "%s", z);
+  sqlite3_free(z);
+}
+#endif
+
+
+/*
+** Determines if a string is a number of not.
+*/
+static int isNumber(const char *z, int *realnum){
+  if( *z=='-' || *z=='+' ) z++;
+  if( !isdigit(*z) ){
+    return 0;
+  }
+  z++;
+  if( realnum ) *realnum = 0;
+  while( isdigit(*z) ){ z++; }
+  if( *z=='.' ){
+    z++;
+    if( !isdigit(*z) ) return 0;
+    while( isdigit(*z) ){ z++; }
+    if( realnum ) *realnum = 1;
+  }
+  if( *z=='e' || *z=='E' ){
+    z++;
+    if( *z=='+' || *z=='-' ) z++;
+    if( !isdigit(*z) ) return 0;
+    while( isdigit(*z) ){ z++; }
+    if( realnum ) *realnum = 1;
+  }
+  return *z==0;
+}
+
+/*
+** A global char* and an SQL function to access its current value 
+** from within an SQL statement. This program used to use the 
+** sqlite_exec_printf() API to substitue a string into an SQL statement.
+** The correct way to do this with sqlite3 is to use the bind API, but
+** since the shell is built around the callback paradigm it would be a lot
+** of work. Instead just use this hack, which is quite harmless.
+*/
+static const char *zShellStatic = 0;
+static void shellstaticFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  assert( 0==argc );
+  assert( zShellStatic );
+  sqlite3_result_text(context, zShellStatic, -1, SQLITE_STATIC);
+}
+
+
+/*
+** This routine reads a line of text from FILE in, stores
+** the text in memory obtained from malloc() and returns a pointer
+** to the text.  NULL is returned at end of file, or if malloc()
+** fails.
+**
+** The interface is like "readline" but no command-line editing
+** is done.
+*/
+static char *local_getline(char *zPrompt, FILE *in){
+  char *zLine;
+  int nLine;
+  int n;
+  int eol;
+
+  if( zPrompt && *zPrompt ){
+    printf("%s",zPrompt);
+    fflush(stdout);
+  }
+  nLine = 100;
+  zLine = malloc( nLine );
+  if( zLine==0 ) return 0;
+  n = 0;
+  eol = 0;
+  while( !eol ){
+    if( n+100>nLine ){
+      nLine = nLine*2 + 100;
+      zLine = realloc(zLine, nLine);
+      if( zLine==0 ) return 0;
+    }
+    if( fgets(&zLine[n], nLine - n, in)==0 ){
+      if( n==0 ){
+        free(zLine);
+        return 0;
+      }
+      zLine[n] = 0;
+      eol = 1;
+      break;
+    }
+    while( zLine[n] ){ n++; }
+    if( n>0 && zLine[n-1]=='\n' ){
+      n--;
+      zLine[n] = 0;
+      eol = 1;
+    }
+  }
+  zLine = realloc( zLine, n+1 );
+  return zLine;
+}
+
+/*
+** Retrieve a single line of input text.
+**
+** zPrior is a string of prior text retrieved.  If not the empty
+** string, then issue a continuation prompt.
+*/
+static char *one_input_line(const char *zPrior, FILE *in){
+  char *zPrompt;
+  char *zResult;
+  if( in!=0 ){
+    return local_getline(0, in);
+  }
+  if( zPrior && zPrior[0] ){
+    zPrompt = continuePrompt;
+  }else{
+    zPrompt = mainPrompt;
+  }
+  zResult = readline(zPrompt);
+#if defined(HAVE_READLINE) && HAVE_READLINE==1
+  if( zResult && *zResult ) add_history(zResult);
+#endif
+  return zResult;
+}
+
+struct previous_mode_data {
+  int valid;        /* Is there legit data in here? */
+  int mode;
+  int showHeader;
+  int colWidth[100];
+};
+
+/*
+** An pointer to an instance of this structure is passed from
+** the main program to the callback.  This is used to communicate
+** state and mode information.
+*/
+struct callback_data {
+  sqlite3 *db;            /* The database */
+  int echoOn;            /* True to echo input commands */
+  int cnt;               /* Number of records displayed so far */
+  FILE *out;             /* Write results here */
+  int mode;              /* An output mode setting */
+  int writableSchema;    /* True if PRAGMA writable_schema=ON */
+  int showHeader;        /* True to show column names in List or Column mode */
+  char *zDestTable;      /* Name of destination table when MODE_Insert */
+  char separator[20];    /* Separator character for MODE_List */
+  int colWidth[100];     /* Requested width of each column when in column mode*/
+  int actualWidth[100];  /* Actual width of each column */
+  char nullvalue[20];    /* The text to print when a NULL comes back from
+                         ** the database */
+  struct previous_mode_data explainPrev;
+                         /* Holds the mode information just before
+                         ** .explain ON */
+  char outfile[FILENAME_MAX]; /* Filename for *out */
+  const char *zDbFilename;    /* name of the database file */
+};
+
+/*
+** These are the allowed modes.
+*/
+#define MODE_Line     0  /* One column per line.  Blank line between records */
+#define MODE_Column   1  /* One record per line in neat columns */
+#define MODE_List     2  /* One record per line with a separator */
+#define MODE_Semi     3  /* Same as MODE_List but append ";" to each line */
+#define MODE_Html     4  /* Generate an XHTML table */
+#define MODE_Insert   5  /* Generate SQL "insert" statements */
+#define MODE_Tcl      6  /* Generate ANSI-C or TCL quoted elements */
+#define MODE_Csv      7  /* Quote strings, numbers are plain */
+#define MODE_Explain  8  /* Like MODE_Column, but do not truncate data */
+
+static const char *modeDescr[] = {
+  "line",
+  "column",
+  "list",
+  "semi",
+  "html",
+  "insert",
+  "tcl",
+  "csv",
+  "explain",
+};
+
+/*
+** Number of elements in an array
+*/
+#define ArraySize(X)  (sizeof(X)/sizeof(X[0]))
+
+/*
+** Output the given string as a quoted string using SQL quoting conventions.
+*/
+static void output_quoted_string(FILE *out, const char *z){
+  int i;
+  int nSingle = 0;
+  for(i=0; z[i]; i++){
+    if( z[i]=='\'' ) nSingle++;
+  }
+  if( nSingle==0 ){
+    fprintf(out,"'%s'",z);
+  }else{
+    fprintf(out,"'");
+    while( *z ){
+      for(i=0; z[i] && z[i]!='\''; i++){}
+      if( i==0 ){
+        fprintf(out,"''");
+        z++;
+      }else if( z[i]=='\'' ){
+        fprintf(out,"%.*s''",i,z);
+        z += i+1;
+      }else{
+        fprintf(out,"%s",z);
+        break;
+      }
+    }
+    fprintf(out,"'");
+  }
+}
+
+/*
+** Output the given string as a quoted according to C or TCL quoting rules.
+*/
+static void output_c_string(FILE *out, const char *z){
+  unsigned int c;
+  fputc('"', out);
+  while( (c = *(z++))!=0 ){
+    if( c=='\\' ){
+      fputc(c, out);
+      fputc(c, out);
+    }else if( c=='\t' ){
+      fputc('\\', out);
+      fputc('t', out);
+    }else if( c=='\n' ){
+      fputc('\\', out);
+      fputc('n', out);
+    }else if( c=='\r' ){
+      fputc('\\', out);
+      fputc('r', out);
+    }else if( !isprint(c) ){
+      fprintf(out, "\\%03o", c&0xff);
+    }else{
+      fputc(c, out);
+    }
+  }
+  fputc('"', out);
+}
+
+/*
+** Output the given string with characters that are special to
+** HTML escaped.
+*/
+static void output_html_string(FILE *out, const char *z){
+  int i;
+  while( *z ){
+    for(i=0; z[i] && z[i]!='<' && z[i]!='&'; i++){}
+    if( i>0 ){
+      fprintf(out,"%.*s",i,z);
+    }
+    if( z[i]=='<' ){
+      fprintf(out,"&lt;");
+    }else if( z[i]=='&' ){
+      fprintf(out,"&amp;");
+    }else{
+      break;
+    }
+    z += i + 1;
+  }
+}
+
+/*
+** If a field contains any character identified by a 1 in the following
+** array, then the string must be quoted for CSV.
+*/
+static const char needCsvQuote[] = {
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
+  1, 0, 1, 0, 0, 0, 0, 1,   0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 1, 
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
+};
+
+/*
+** Output a single term of CSV.  Actually, p->separator is used for
+** the separator, which may or may not be a comma.  p->nullvalue is
+** the null value.  Strings are quoted using ANSI-C rules.  Numbers
+** appear outside of quotes.
+*/
+static void output_csv(struct callback_data *p, const char *z, int bSep){
+  FILE *out = p->out;
+  if( z==0 ){
+    fprintf(out,"%s",p->nullvalue);
+  }else{
+    int i;
+    int nSep = strlen(p->separator);
+    for(i=0; z[i]; i++){
+      if( needCsvQuote[((unsigned char*)z)[i]] 
+         || (z[i]==p->separator[0] && 
+             (nSep==1 || memcmp(z, p->separator, nSep)==0)) ){
+        i = 0;
+        break;
+      }
+    }
+    if( i==0 ){
+      putc('"', out);
+      for(i=0; z[i]; i++){
+        if( z[i]=='"' ) putc('"', out);
+        putc(z[i], out);
+      }
+      putc('"', out);
+    }else{
+      fprintf(out, "%s", z);
+    }
+  }
+  if( bSep ){
+    fprintf(p->out, "%s", p->separator);
+  }
+}
+
+#ifdef SIGINT
+/*
+** This routine runs when the user presses Ctrl-C
+*/
+static void interrupt_handler(int NotUsed){
+  seenInterrupt = 1;
+  if( db ) sqlite3_interrupt(db);
+}
+#endif
+
+/*
+** This is the callback routine that the SQLite library
+** invokes for each row of a query result.
+*/
+static int callback(void *pArg, int nArg, char **azArg, char **azCol){
+  int i;
+  struct callback_data *p = (struct callback_data*)pArg;
+  switch( p->mode ){
+    case MODE_Line: {
+      int w = 5;
+      if( azArg==0 ) break;
+      for(i=0; i<nArg; i++){
+        int len = strlen(azCol[i] ? azCol[i] : "");
+        if( len>w ) w = len;
+      }
+      if( p->cnt++>0 ) fprintf(p->out,"\n");
+      for(i=0; i<nArg; i++){
+        fprintf(p->out,"%*s = %s\n", w, azCol[i],
+                azArg[i] ? azArg[i] : p->nullvalue);
+      }
+      break;
+    }
+    case MODE_Explain:
+    case MODE_Column: {
+      if( p->cnt++==0 ){
+        for(i=0; i<nArg; i++){
+          int w, n;
+          if( i<ArraySize(p->colWidth) ){
+            w = p->colWidth[i];
+          }else{
+            w = 0;
+          }
+          if( w<=0 ){
+            w = strlen(azCol[i] ? azCol[i] : "");
+            if( w<10 ) w = 10;
+            n = strlen(azArg && azArg[i] ? azArg[i] : p->nullvalue);
+            if( w<n ) w = n;
+          }
+          if( i<ArraySize(p->actualWidth) ){
+            p->actualWidth[i] = w;
+          }
+          if( p->showHeader ){
+            fprintf(p->out,"%-*.*s%s",w,w,azCol[i], i==nArg-1 ? "\n": "  ");
+          }
+        }
+        if( p->showHeader ){
+          for(i=0; i<nArg; i++){
+            int w;
+            if( i<ArraySize(p->actualWidth) ){
+               w = p->actualWidth[i];
+            }else{
+               w = 10;
+            }
+            fprintf(p->out,"%-*.*s%s",w,w,"-----------------------------------"
+                   "----------------------------------------------------------",
+                    i==nArg-1 ? "\n": "  ");
+          }
+        }
+      }
+      if( azArg==0 ) break;
+      for(i=0; i<nArg; i++){
+        int w;
+        if( i<ArraySize(p->actualWidth) ){
+           w = p->actualWidth[i];
+        }else{
+           w = 10;
+        }
+        if( p->mode==MODE_Explain && azArg[i] && strlen(azArg[i])>w ){
+          w = strlen(azArg[i]);
+        }
+        fprintf(p->out,"%-*.*s%s",w,w,
+            azArg[i] ? azArg[i] : p->nullvalue, i==nArg-1 ? "\n": "  ");
+      }
+      break;
+    }
+    case MODE_Semi:
+    case MODE_List: {
+      if( p->cnt++==0 && p->showHeader ){
+        for(i=0; i<nArg; i++){
+          fprintf(p->out,"%s%s",azCol[i], i==nArg-1 ? "\n" : p->separator);
+        }
+      }
+      if( azArg==0 ) break;
+      for(i=0; i<nArg; i++){
+        char *z = azArg[i];
+        if( z==0 ) z = p->nullvalue;
+        fprintf(p->out, "%s", z);
+        if( i<nArg-1 ){
+          fprintf(p->out, "%s", p->separator);
+        }else if( p->mode==MODE_Semi ){
+          fprintf(p->out, ";\n");
+        }else{
+          fprintf(p->out, "\n");
+        }
+      }
+      break;
+    }
+    case MODE_Html: {
+      if( p->cnt++==0 && p->showHeader ){
+        fprintf(p->out,"<TR>");
+        for(i=0; i<nArg; i++){
+          fprintf(p->out,"<TH>%s</TH>",azCol[i]);
+        }
+        fprintf(p->out,"</TR>\n");
+      }
+      if( azArg==0 ) break;
+      fprintf(p->out,"<TR>");
+      for(i=0; i<nArg; i++){
+        fprintf(p->out,"<TD>");
+        output_html_string(p->out, azArg[i] ? azArg[i] : p->nullvalue);
+        fprintf(p->out,"</TD>\n");
+      }
+      fprintf(p->out,"</TR>\n");
+      break;
+    }
+    case MODE_Tcl: {
+      if( p->cnt++==0 && p->showHeader ){
+        for(i=0; i<nArg; i++){
+          output_c_string(p->out,azCol[i] ? azCol[i] : "");
+          fprintf(p->out, "%s", p->separator);
+        }
+        fprintf(p->out,"\n");
+      }
+      if( azArg==0 ) break;
+      for(i=0; i<nArg; i++){
+        output_c_string(p->out, azArg[i] ? azArg[i] : p->nullvalue);
+        fprintf(p->out, "%s", p->separator);
+      }
+      fprintf(p->out,"\n");
+      break;
+    }
+    case MODE_Csv: {
+      if( p->cnt++==0 && p->showHeader ){
+        for(i=0; i<nArg; i++){
+          output_csv(p, azCol[i] ? azCol[i] : "", i<nArg-1);
+        }
+        fprintf(p->out,"\n");
+      }
+      if( azArg==0 ) break;
+      for(i=0; i<nArg; i++){
+        output_csv(p, azArg[i], i<nArg-1);
+      }
+      fprintf(p->out,"\n");
+      break;
+    }
+    case MODE_Insert: {
+      if( azArg==0 ) break;
+      fprintf(p->out,"INSERT INTO %s VALUES(",p->zDestTable);
+      for(i=0; i<nArg; i++){
+        char *zSep = i>0 ? ",": "";
+        if( azArg[i]==0 ){
+          fprintf(p->out,"%sNULL",zSep);
+        }else if( isNumber(azArg[i], 0) ){
+          fprintf(p->out,"%s%s",zSep, azArg[i]);
+        }else{
+          if( zSep[0] ) fprintf(p->out,"%s",zSep);
+          output_quoted_string(p->out, azArg[i]);
+        }
+      }
+      fprintf(p->out,");\n");
+      break;
+    }
+  }
+  return 0;
+}
+
+/*
+** Set the destination table field of the callback_data structure to
+** the name of the table given.  Escape any quote characters in the
+** table name.
+*/
+static void set_table_name(struct callback_data *p, const char *zName){
+  int i, n;
+  int needQuote;
+  char *z;
+
+  if( p->zDestTable ){
+    free(p->zDestTable);
+    p->zDestTable = 0;
+  }
+  if( zName==0 ) return;
+  needQuote = !isalpha((unsigned char)*zName) && *zName!='_';
+  for(i=n=0; zName[i]; i++, n++){
+    if( !isalnum((unsigned char)zName[i]) && zName[i]!='_' ){
+      needQuote = 1;
+      if( zName[i]=='\'' ) n++;
+    }
+  }
+  if( needQuote ) n += 2;
+  z = p->zDestTable = malloc( n+1 );
+  if( z==0 ){
+    fprintf(stderr,"Out of memory!\n");
+    exit(1);
+  }
+  n = 0;
+  if( needQuote ) z[n++] = '\'';
+  for(i=0; zName[i]; i++){
+    z[n++] = zName[i];
+    if( zName[i]=='\'' ) z[n++] = '\'';
+  }
+  if( needQuote ) z[n++] = '\'';
+  z[n] = 0;
+}
+
+/* zIn is either a pointer to a NULL-terminated string in memory obtained
+** from malloc(), or a NULL pointer. The string pointed to by zAppend is
+** added to zIn, and the result returned in memory obtained from malloc().
+** zIn, if it was not NULL, is freed.
+**
+** If the third argument, quote, is not '\0', then it is used as a 
+** quote character for zAppend.
+*/
+static char *appendText(char *zIn, char const *zAppend, char quote){
+  int len;
+  int i;
+  int nAppend = strlen(zAppend);
+  int nIn = (zIn?strlen(zIn):0);
+
+  len = nAppend+nIn+1;
+  if( quote ){
+    len += 2;
+    for(i=0; i<nAppend; i++){
+      if( zAppend[i]==quote ) len++;
+    }
+  }
+
+  zIn = (char *)realloc(zIn, len);
+  if( !zIn ){
+    return 0;
+  }
+
+  if( quote ){
+    char *zCsr = &zIn[nIn];
+    *zCsr++ = quote;
+    for(i=0; i<nAppend; i++){
+      *zCsr++ = zAppend[i];
+      if( zAppend[i]==quote ) *zCsr++ = quote;
+    }
+    *zCsr++ = quote;
+    *zCsr++ = '\0';
+    assert( (zCsr-zIn)==len );
+  }else{
+    memcpy(&zIn[nIn], zAppend, nAppend);
+    zIn[len-1] = '\0';
+  }
+
+  return zIn;
+}
+
+
+/*
+** Execute a query statement that has a single result column.  Print
+** that result column on a line by itself with a semicolon terminator.
+**
+** This is used, for example, to show the schema of the database by
+** querying the SQLITE_MASTER table.
+*/
+static int run_table_dump_query(FILE *out, sqlite3 *db, const char *zSelect){
+  sqlite3_stmt *pSelect;
+  int rc;
+  rc = sqlite3_prepare(db, zSelect, -1, &pSelect, 0);
+  if( rc!=SQLITE_OK || !pSelect ){
+    return rc;
+  }
+  rc = sqlite3_step(pSelect);
+  while( rc==SQLITE_ROW ){
+    fprintf(out, "%s;\n", sqlite3_column_text(pSelect, 0));
+    rc = sqlite3_step(pSelect);
+  }
+  return sqlite3_finalize(pSelect);
+}
+
+
+/*
+** This is a different callback routine used for dumping the database.
+** Each row received by this callback consists of a table name,
+** the table type ("index" or "table") and SQL to create the table.
+** This routine should print text sufficient to recreate the table.
+*/
+static int dump_callback(void *pArg, int nArg, char **azArg, char **azCol){
+  int rc;
+  const char *zTable;
+  const char *zType;
+  const char *zSql;
+  struct callback_data *p = (struct callback_data *)pArg;
+
+  if( nArg!=3 ) return 1;
+  zTable = azArg[0];
+  zType = azArg[1];
+  zSql = azArg[2];
+  
+  if( strcmp(zTable, "sqlite_sequence")==0 ){
+    fprintf(p->out, "DELETE FROM sqlite_sequence;\n");
+  }else if( strcmp(zTable, "sqlite_stat1")==0 ){
+    fprintf(p->out, "ANALYZE sqlite_master;\n");
+  }else if( strncmp(zTable, "sqlite_", 7)==0 ){
+    return 0;
+  }else if( strncmp(zSql, "CREATE VIRTUAL TABLE", 20)==0 ){
+    char *zIns;
+    if( !p->writableSchema ){
+      fprintf(p->out, "PRAGMA writable_schema=ON;\n");
+      p->writableSchema = 1;
+    }
+    zIns = sqlite3_mprintf(
+       "INSERT INTO sqlite_master(type,name,tbl_name,rootpage,sql)"
+       "VALUES('table','%q','%q',0,'%q');",
+       zTable, zTable, zSql);
+    fprintf(p->out, "%s\n", zIns);
+    sqlite3_free(zIns);
+    return 0;
+  }else{
+    fprintf(p->out, "%s;\n", zSql);
+  }
+
+  if( strcmp(zType, "table")==0 ){
+    sqlite3_stmt *pTableInfo = 0;
+    char *zSelect = 0;
+    char *zTableInfo = 0;
+    char *zTmp = 0;
+   
+    zTableInfo = appendText(zTableInfo, "PRAGMA table_info(", 0);
+    zTableInfo = appendText(zTableInfo, zTable, '"');
+    zTableInfo = appendText(zTableInfo, ");", 0);
+
+    rc = sqlite3_prepare(p->db, zTableInfo, -1, &pTableInfo, 0);
+    if( zTableInfo ) free(zTableInfo);
+    if( rc!=SQLITE_OK || !pTableInfo ){
+      return 1;
+    }
+
+    zSelect = appendText(zSelect, "SELECT 'INSERT INTO ' || ", 0);
+    zTmp = appendText(zTmp, zTable, '"');
+    if( zTmp ){
+      zSelect = appendText(zSelect, zTmp, '\'');
+    }
+    zSelect = appendText(zSelect, " || ' VALUES(' || ", 0);
+    rc = sqlite3_step(pTableInfo);
+    while( rc==SQLITE_ROW ){
+      const char *zText = (const char *)sqlite3_column_text(pTableInfo, 1);
+      zSelect = appendText(zSelect, "quote(", 0);
+      zSelect = appendText(zSelect, zText, '"');
+      rc = sqlite3_step(pTableInfo);
+      if( rc==SQLITE_ROW ){
+        zSelect = appendText(zSelect, ") || ',' || ", 0);
+      }else{
+        zSelect = appendText(zSelect, ") ", 0);
+      }
+    }
+    rc = sqlite3_finalize(pTableInfo);
+    if( rc!=SQLITE_OK ){
+      if( zSelect ) free(zSelect);
+      return 1;
+    }
+    zSelect = appendText(zSelect, "|| ')' FROM  ", 0);
+    zSelect = appendText(zSelect, zTable, '"');
+
+    rc = run_table_dump_query(p->out, p->db, zSelect);
+    if( rc==SQLITE_CORRUPT ){
+      zSelect = appendText(zSelect, " ORDER BY rowid DESC", 0);
+      rc = run_table_dump_query(p->out, p->db, zSelect);
+    }
+    if( zSelect ) free(zSelect);
+  }
+  return 0;
+}
+
+/*
+** Run zQuery.  Use dump_callback() as the callback routine so that
+** the contents of the query are output as SQL statements.
+**
+** If we get a SQLITE_CORRUPT error, rerun the query after appending
+** "ORDER BY rowid DESC" to the end.
+*/
+static int run_schema_dump_query(
+  struct callback_data *p, 
+  const char *zQuery,
+  char **pzErrMsg
+){
+  int rc;
+  rc = sqlite3_exec(p->db, zQuery, dump_callback, p, pzErrMsg);
+  if( rc==SQLITE_CORRUPT ){
+    char *zQ2;
+    int len = strlen(zQuery);
+    if( pzErrMsg ) sqlite3_free(*pzErrMsg);
+    zQ2 = malloc( len+100 );
+    if( zQ2==0 ) return rc;
+    sqlite3_snprintf(sizeof(zQ2), zQ2, "%s ORDER BY rowid DESC", zQuery);
+    rc = sqlite3_exec(p->db, zQ2, dump_callback, p, pzErrMsg);
+    free(zQ2);
+  }
+  return rc;
+}
+
+/*
+** Text of a help message
+*/
+static char zHelp[] =
+  ".bail ON|OFF           Stop after hitting an error.  Default OFF\n"
+  ".databases             List names and files of attached databases\n"
+  ".dump ?TABLE? ...      Dump the database in an SQL text format\n"
+  ".echo ON|OFF           Turn command echo on or off\n"
+  ".exit                  Exit this program\n"
+  ".explain ON|OFF        Turn output mode suitable for EXPLAIN on or off.\n"
+  ".header(s) ON|OFF      Turn display of headers on or off\n"
+  ".help                  Show this message\n"
+  ".import FILE TABLE     Import data from FILE into TABLE\n"
+  ".indices TABLE         Show names of all indices on TABLE\n"
+#ifdef SQLITE_ENABLE_IOTRACE
+  ".iotrace FILE          Enable I/O diagnostic logging to FILE\n"
+#endif
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+  ".load FILE ?ENTRY?     Load an extension library\n"
+#endif
+  ".mode MODE ?TABLE?     Set output mode where MODE is one of:\n"
+  "                         csv      Comma-separated values\n"
+  "                         column   Left-aligned columns.  (See .width)\n"
+  "                         html     HTML <table> code\n"
+  "                         insert   SQL insert statements for TABLE\n"
+  "                         line     One value per line\n"
+  "                         list     Values delimited by .separator string\n"
+  "                         tabs     Tab-separated values\n"
+  "                         tcl      TCL list elements\n"
+  ".nullvalue STRING      Print STRING in place of NULL values\n"
+  ".output FILENAME       Send output to FILENAME\n"
+  ".output stdout         Send output to the screen\n"
+  ".prompt MAIN CONTINUE  Replace the standard prompts\n"
+  ".quit                  Exit this program\n"
+  ".read FILENAME         Execute SQL in FILENAME\n"
+  ".schema ?TABLE?        Show the CREATE statements\n"
+  ".separator STRING      Change separator used by output mode and .import\n"
+  ".show                  Show the current values for various settings\n"
+  ".tables ?PATTERN?      List names of tables matching a LIKE pattern\n"
+  ".timeout MS            Try opening locked tables for MS milliseconds\n"
+#if HAS_TIMER
+  ".timer ON|OFF          Turn the CPU timer measurement on or off\n"
+#endif
+  ".width NUM NUM ...     Set column widths for \"column\" mode\n"
+;
+
+/* Forward reference */
+static int process_input(struct callback_data *p, FILE *in);
+
+/*
+** Make sure the database is open.  If it is not, then open it.  If
+** the database fails to open, print an error message and exit.
+*/
+static void open_db(struct callback_data *p){
+  if( p->db==0 ){
+    sqlite3_open(p->zDbFilename, &p->db);
+    db = p->db;
+    if( db && sqlite3_errcode(db)==SQLITE_OK ){
+      sqlite3_create_function(db, "shellstatic", 0, SQLITE_UTF8, 0,
+          shellstaticFunc, 0, 0);
+    }
+    if( db==0 || SQLITE_OK!=sqlite3_errcode(db) ){
+      fprintf(stderr,"Unable to open database \"%s\": %s\n", 
+          p->zDbFilename, sqlite3_errmsg(db));
+      exit(1);
+    }
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+    sqlite3_enable_load_extension(p->db, 1);
+#endif
+  }
+}
+
+/*
+** Do C-language style dequoting.
+**
+**    \t    -> tab
+**    \n    -> newline
+**    \r    -> carriage return
+**    \NNN  -> ascii character NNN in octal
+**    \\    -> backslash
+*/
+static void resolve_backslashes(char *z){
+  int i, j, c;
+  for(i=j=0; (c = z[i])!=0; i++, j++){
+    if( c=='\\' ){
+      c = z[++i];
+      if( c=='n' ){
+        c = '\n';
+      }else if( c=='t' ){
+        c = '\t';
+      }else if( c=='r' ){
+        c = '\r';
+      }else if( c>='0' && c<='7' ){
+        c -= '0';
+        if( z[i+1]>='0' && z[i+1]<='7' ){
+          i++;
+          c = (c<<3) + z[i] - '0';
+          if( z[i+1]>='0' && z[i+1]<='7' ){
+            i++;
+            c = (c<<3) + z[i] - '0';
+          }
+        }
+      }
+    }
+    z[j] = c;
+  }
+  z[j] = 0;
+}
+
+/*
+** Interpret zArg as a boolean value.  Return either 0 or 1.
+*/
+static int booleanValue(char *zArg){
+  int val = atoi(zArg);
+  int j;
+  for(j=0; zArg[j]; j++){
+    zArg[j] = tolower(zArg[j]);
+  }
+  if( strcmp(zArg,"on")==0 ){
+    val = 1;
+  }else if( strcmp(zArg,"yes")==0 ){
+    val = 1;
+  }
+  return val;
+}
+
+/*
+** If an input line begins with "." then invoke this routine to
+** process that line.
+**
+** Return 1 on error, 2 to exit, and 0 otherwise.
+*/
+static int do_meta_command(char *zLine, struct callback_data *p){
+  int i = 1;
+  int nArg = 0;
+  int n, c;
+  int rc = 0;
+  char *azArg[50];
+
+  /* Parse the input line into tokens.
+  */
+  while( zLine[i] && nArg<ArraySize(azArg) ){
+    while( isspace((unsigned char)zLine[i]) ){ i++; }
+    if( zLine[i]==0 ) break;
+    if( zLine[i]=='\'' || zLine[i]=='"' ){
+      int delim = zLine[i++];
+      azArg[nArg++] = &zLine[i];
+      while( zLine[i] && zLine[i]!=delim ){ i++; }
+      if( zLine[i]==delim ){
+        zLine[i++] = 0;
+      }
+      if( delim=='"' ) resolve_backslashes(azArg[nArg-1]);
+    }else{
+      azArg[nArg++] = &zLine[i];
+      while( zLine[i] && !isspace((unsigned char)zLine[i]) ){ i++; }
+      if( zLine[i] ) zLine[i++] = 0;
+      resolve_backslashes(azArg[nArg-1]);
+    }
+  }
+
+  /* Process the input line.
+  */
+  if( nArg==0 ) return rc;
+  n = strlen(azArg[0]);
+  c = azArg[0][0];
+  if( c=='b' && n>1 && strncmp(azArg[0], "bail", n)==0 && nArg>1 ){
+    bail_on_error = booleanValue(azArg[1]);
+  }else
+
+  if( c=='d' && n>1 && strncmp(azArg[0], "databases", n)==0 ){
+    struct callback_data data;
+    char *zErrMsg = 0;
+    open_db(p);
+    memcpy(&data, p, sizeof(data));
+    data.showHeader = 1;
+    data.mode = MODE_Column;
+    data.colWidth[0] = 3;
+    data.colWidth[1] = 15;
+    data.colWidth[2] = 58;
+    data.cnt = 0;
+    sqlite3_exec(p->db, "PRAGMA database_list; ", callback, &data, &zErrMsg);
+    if( zErrMsg ){
+      fprintf(stderr,"Error: %s\n", zErrMsg);
+      sqlite3_free(zErrMsg);
+    }
+  }else
+
+  if( c=='d' && strncmp(azArg[0], "dump", n)==0 ){
+    char *zErrMsg = 0;
+    open_db(p);
+    fprintf(p->out, "BEGIN TRANSACTION;\n");
+    p->writableSchema = 0;
+    if( nArg==1 ){
+      run_schema_dump_query(p, 
+        "SELECT name, type, sql FROM sqlite_master "
+        "WHERE sql NOT NULL AND type=='table'", 0
+      );
+      run_table_dump_query(p->out, p->db,
+        "SELECT sql FROM sqlite_master "
+        "WHERE sql NOT NULL AND type IN ('index','trigger','view')"
+      );
+    }else{
+      int i;
+      for(i=1; i<nArg; i++){
+        zShellStatic = azArg[i];
+        run_schema_dump_query(p,
+          "SELECT name, type, sql FROM sqlite_master "
+          "WHERE tbl_name LIKE shellstatic() AND type=='table'"
+          "  AND sql NOT NULL", 0);
+        run_table_dump_query(p->out, p->db,
+          "SELECT sql FROM sqlite_master "
+          "WHERE sql NOT NULL"
+          "  AND type IN ('index','trigger','view')"
+          "  AND tbl_name LIKE shellstatic()"
+        );
+        zShellStatic = 0;
+      }
+    }
+    if( p->writableSchema ){
+      fprintf(p->out, "PRAGMA writable_schema=OFF;\n");
+      p->writableSchema = 0;
+    }
+    if( zErrMsg ){
+      fprintf(stderr,"Error: %s\n", zErrMsg);
+      sqlite3_free(zErrMsg);
+    }else{
+      fprintf(p->out, "COMMIT;\n");
+    }
+  }else
+
+  if( c=='e' && strncmp(azArg[0], "echo", n)==0 && nArg>1 ){
+    p->echoOn = booleanValue(azArg[1]);
+  }else
+
+  if( c=='e' && strncmp(azArg[0], "exit", n)==0 ){
+    rc = 2;
+  }else
+
+  if( c=='e' && strncmp(azArg[0], "explain", n)==0 ){
+    int val = nArg>=2 ? booleanValue(azArg[1]) : 1;
+    if(val == 1) {
+      if(!p->explainPrev.valid) {
+        p->explainPrev.valid = 1;
+        p->explainPrev.mode = p->mode;
+        p->explainPrev.showHeader = p->showHeader;
+        memcpy(p->explainPrev.colWidth,p->colWidth,sizeof(p->colWidth));
+      }
+      /* We could put this code under the !p->explainValid
+      ** condition so that it does not execute if we are already in
+      ** explain mode. However, always executing it allows us an easy
+      ** was to reset to explain mode in case the user previously
+      ** did an .explain followed by a .width, .mode or .header
+      ** command.
+      */
+      p->mode = MODE_Explain;
+      p->showHeader = 1;
+      memset(p->colWidth,0,ArraySize(p->colWidth));
+      p->colWidth[0] = 4;                  /* addr */
+      p->colWidth[1] = 13;                 /* opcode */
+      p->colWidth[2] = 4;                  /* P1 */
+      p->colWidth[3] = 4;                  /* P2 */
+      p->colWidth[4] = 4;                  /* P3 */
+      p->colWidth[5] = 13;                 /* P4 */
+      p->colWidth[6] = 2;                  /* P5 */
+      p->colWidth[7] = 13;                  /* Comment */
+    }else if (p->explainPrev.valid) {
+      p->explainPrev.valid = 0;
+      p->mode = p->explainPrev.mode;
+      p->showHeader = p->explainPrev.showHeader;
+      memcpy(p->colWidth,p->explainPrev.colWidth,sizeof(p->colWidth));
+    }
+  }else
+
+  if( c=='h' && (strncmp(azArg[0], "header", n)==0 ||
+                 strncmp(azArg[0], "headers", n)==0 )&& nArg>1 ){
+    p->showHeader = booleanValue(azArg[1]);
+  }else
+
+  if( c=='h' && strncmp(azArg[0], "help", n)==0 ){
+    fprintf(stderr,zHelp);
+  }else
+
+  if( c=='i' && strncmp(azArg[0], "import", n)==0 && nArg>=3 ){
+    char *zTable = azArg[2];    /* Insert data into this table */
+    char *zFile = azArg[1];     /* The file from which to extract data */
+    sqlite3_stmt *pStmt;        /* A statement */
+    int rc;                     /* Result code */
+    int nCol;                   /* Number of columns in the table */
+    int nByte;                  /* Number of bytes in an SQL string */
+    int i, j;                   /* Loop counters */
+    int nSep;                   /* Number of bytes in p->separator[] */
+    char *zSql;                 /* An SQL statement */
+    char *zLine;                /* A single line of input from the file */
+    char **azCol;               /* zLine[] broken up into columns */
+    char *zCommit;              /* How to commit changes */   
+    FILE *in;                   /* The input file */
+    int lineno = 0;             /* Line number of input file */
+
+    open_db(p);
+    nSep = strlen(p->separator);
+    if( nSep==0 ){
+      fprintf(stderr, "non-null separator required for import\n");
+      return 0;
+    }
+    zSql = sqlite3_mprintf("SELECT * FROM '%q'", zTable);
+    if( zSql==0 ) return 0;
+    nByte = strlen(zSql);
+    rc = sqlite3_prepare(p->db, zSql, -1, &pStmt, 0);
+    sqlite3_free(zSql);
+    if( rc ){
+      fprintf(stderr,"Error: %s\n", sqlite3_errmsg(db));
+      nCol = 0;
+      rc = 1;
+    }else{
+      nCol = sqlite3_column_count(pStmt);
+    }
+    sqlite3_finalize(pStmt);
+    if( nCol==0 ) return 0;
+    zSql = malloc( nByte + 20 + nCol*2 );
+    if( zSql==0 ) return 0;
+    sqlite3_snprintf(nByte+20, zSql, "INSERT INTO '%q' VALUES(?", zTable);
+    j = strlen(zSql);
+    for(i=1; i<nCol; i++){
+      zSql[j++] = ',';
+      zSql[j++] = '?';
+    }
+    zSql[j++] = ')';
+    zSql[j] = 0;
+    rc = sqlite3_prepare(p->db, zSql, -1, &pStmt, 0);
+    free(zSql);
+    if( rc ){
+      fprintf(stderr, "Error: %s\n", sqlite3_errmsg(db));
+      sqlite3_finalize(pStmt);
+      return 1;
+    }
+    in = fopen(zFile, "rb");
+    if( in==0 ){
+      fprintf(stderr, "cannot open file: %s\n", zFile);
+      sqlite3_finalize(pStmt);
+      return 0;
+    }
+    azCol = malloc( sizeof(azCol[0])*(nCol+1) );
+    if( azCol==0 ){
+      fclose(in);
+      return 0;
+    }
+    sqlite3_exec(p->db, "BEGIN", 0, 0, 0);
+    zCommit = "COMMIT";
+    while( (zLine = local_getline(0, in))!=0 ){
+      char *z;
+      i = 0;
+      lineno++;
+      azCol[0] = zLine;
+      for(i=0, z=zLine; *z && *z!='\n' && *z!='\r'; z++){
+        if( *z==p->separator[0] && strncmp(z, p->separator, nSep)==0 ){
+          *z = 0;
+          i++;
+          if( i<nCol ){
+            azCol[i] = &z[nSep];
+            z += nSep-1;
+          }
+        }
+      }
+      *z = 0;
+      if( i+1!=nCol ){
+        fprintf(stderr,"%s line %d: expected %d columns of data but found %d\n",
+           zFile, lineno, nCol, i+1);
+        zCommit = "ROLLBACK";
+        break;
+      }
+      for(i=0; i<nCol; i++){
+        sqlite3_bind_text(pStmt, i+1, azCol[i], -1, SQLITE_STATIC);
+      }
+      sqlite3_step(pStmt);
+      rc = sqlite3_reset(pStmt);
+      free(zLine);
+      if( rc!=SQLITE_OK ){
+        fprintf(stderr,"Error: %s\n", sqlite3_errmsg(db));
+        zCommit = "ROLLBACK";
+        rc = 1;
+        break;
+      }
+    }
+    free(azCol);
+    fclose(in);
+    sqlite3_finalize(pStmt);
+    sqlite3_exec(p->db, zCommit, 0, 0, 0);
+  }else
+
+  if( c=='i' && strncmp(azArg[0], "indices", n)==0 && nArg>1 ){
+    struct callback_data data;
+    char *zErrMsg = 0;
+    open_db(p);
+    memcpy(&data, p, sizeof(data));
+    data.showHeader = 0;
+    data.mode = MODE_List;
+    zShellStatic = azArg[1];
+    sqlite3_exec(p->db,
+      "SELECT name FROM sqlite_master "
+      "WHERE type='index' AND tbl_name LIKE shellstatic() "
+      "UNION ALL "
+      "SELECT name FROM sqlite_temp_master "
+      "WHERE type='index' AND tbl_name LIKE shellstatic() "
+      "ORDER BY 1",
+      callback, &data, &zErrMsg
+    );
+    zShellStatic = 0;
+    if( zErrMsg ){
+      fprintf(stderr,"Error: %s\n", zErrMsg);
+      sqlite3_free(zErrMsg);
+    }
+  }else
+
+#ifdef SQLITE_ENABLE_IOTRACE
+  if( c=='i' && strncmp(azArg[0], "iotrace", n)==0 ){
+    extern void (*sqlite3IoTrace)(const char*, ...);
+    if( iotrace && iotrace!=stdout ) fclose(iotrace);
+    iotrace = 0;
+    if( nArg<2 ){
+      sqlite3IoTrace = 0;
+    }else if( strcmp(azArg[1], "-")==0 ){
+      sqlite3IoTrace = iotracePrintf;
+      iotrace = stdout;
+    }else{
+      iotrace = fopen(azArg[1], "w");
+      if( iotrace==0 ){
+        fprintf(stderr, "cannot open \"%s\"\n", azArg[1]);
+        sqlite3IoTrace = 0;
+      }else{
+        sqlite3IoTrace = iotracePrintf;
+      }
+    }
+  }else
+#endif
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+  if( c=='l' && strncmp(azArg[0], "load", n)==0 && nArg>=2 ){
+    const char *zFile, *zProc;
+    char *zErrMsg = 0;
+    int rc;
+    zFile = azArg[1];
+    zProc = nArg>=3 ? azArg[2] : 0;
+    open_db(p);
+    rc = sqlite3_load_extension(p->db, zFile, zProc, &zErrMsg);
+    if( rc!=SQLITE_OK ){
+      fprintf(stderr, "%s\n", zErrMsg);
+      sqlite3_free(zErrMsg);
+      rc = 1;
+    }
+  }else
+#endif
+
+  if( c=='m' && strncmp(azArg[0], "mode", n)==0 && nArg>=2 ){
+    int n2 = strlen(azArg[1]);
+    if( strncmp(azArg[1],"line",n2)==0
+        ||
+        strncmp(azArg[1],"lines",n2)==0 ){
+      p->mode = MODE_Line;
+    }else if( strncmp(azArg[1],"column",n2)==0
+              ||
+              strncmp(azArg[1],"columns",n2)==0 ){
+      p->mode = MODE_Column;
+    }else if( strncmp(azArg[1],"list",n2)==0 ){
+      p->mode = MODE_List;
+    }else if( strncmp(azArg[1],"html",n2)==0 ){
+      p->mode = MODE_Html;
+    }else if( strncmp(azArg[1],"tcl",n2)==0 ){
+      p->mode = MODE_Tcl;
+    }else if( strncmp(azArg[1],"csv",n2)==0 ){
+      p->mode = MODE_Csv;
+      sqlite3_snprintf(sizeof(p->separator), p->separator, ",");
+    }else if( strncmp(azArg[1],"tabs",n2)==0 ){
+      p->mode = MODE_List;
+      sqlite3_snprintf(sizeof(p->separator), p->separator, "\t");
+    }else if( strncmp(azArg[1],"insert",n2)==0 ){
+      p->mode = MODE_Insert;
+      if( nArg>=3 ){
+        set_table_name(p, azArg[2]);
+      }else{
+        set_table_name(p, "table");
+      }
+    }else {
+      fprintf(stderr,"mode should be one of: "
+         "column csv html insert line list tabs tcl\n");
+    }
+  }else
+
+  if( c=='n' && strncmp(azArg[0], "nullvalue", n)==0 && nArg==2 ) {
+    sqlite3_snprintf(sizeof(p->nullvalue), p->nullvalue,
+                     "%.*s", (int)ArraySize(p->nullvalue)-1, azArg[1]);
+  }else
+
+  if( c=='o' && strncmp(azArg[0], "output", n)==0 && nArg==2 ){
+    if( p->out!=stdout ){
+      fclose(p->out);
+    }
+    if( strcmp(azArg[1],"stdout")==0 ){
+      p->out = stdout;
+      sqlite3_snprintf(sizeof(p->outfile), p->outfile, "stdout");
+    }else{
+      p->out = fopen(azArg[1], "wb");
+      if( p->out==0 ){
+        fprintf(stderr,"can't write to \"%s\"\n", azArg[1]);
+        p->out = stdout;
+      } else {
+         sqlite3_snprintf(sizeof(p->outfile), p->outfile, "%s", azArg[1]);
+      }
+    }
+  }else
+
+  if( c=='p' && strncmp(azArg[0], "prompt", n)==0 && (nArg==2 || nArg==3)){
+    if( nArg >= 2) {
+      strncpy(mainPrompt,azArg[1],(int)ArraySize(mainPrompt)-1);
+    }
+    if( nArg >= 3) {
+      strncpy(continuePrompt,azArg[2],(int)ArraySize(continuePrompt)-1);
+    }
+  }else
+
+  if( c=='q' && strncmp(azArg[0], "quit", n)==0 ){
+    rc = 2;
+  }else
+
+  if( c=='r' && strncmp(azArg[0], "read", n)==0 && nArg==2 ){
+    FILE *alt = fopen(azArg[1], "rb");
+    if( alt==0 ){
+      fprintf(stderr,"can't open \"%s\"\n", azArg[1]);
+    }else{
+      process_input(p, alt);
+      fclose(alt);
+    }
+  }else
+
+  if( c=='s' && strncmp(azArg[0], "schema", n)==0 ){
+    struct callback_data data;
+    char *zErrMsg = 0;
+    open_db(p);
+    memcpy(&data, p, sizeof(data));
+    data.showHeader = 0;
+    data.mode = MODE_Semi;
+    if( nArg>1 ){
+      int i;
+      for(i=0; azArg[1][i]; i++) azArg[1][i] = tolower(azArg[1][i]);
+      if( strcmp(azArg[1],"sqlite_master")==0 ){
+        char *new_argv[2], *new_colv[2];
+        new_argv[0] = "CREATE TABLE sqlite_master (\n"
+                      "  type text,\n"
+                      "  name text,\n"
+                      "  tbl_name text,\n"
+                      "  rootpage integer,\n"
+                      "  sql text\n"
+                      ")";
+        new_argv[1] = 0;
+        new_colv[0] = "sql";
+        new_colv[1] = 0;
+        callback(&data, 1, new_argv, new_colv);
+      }else if( strcmp(azArg[1],"sqlite_temp_master")==0 ){
+        char *new_argv[2], *new_colv[2];
+        new_argv[0] = "CREATE TEMP TABLE sqlite_temp_master (\n"
+                      "  type text,\n"
+                      "  name text,\n"
+                      "  tbl_name text,\n"
+                      "  rootpage integer,\n"
+                      "  sql text\n"
+                      ")";
+        new_argv[1] = 0;
+        new_colv[0] = "sql";
+        new_colv[1] = 0;
+        callback(&data, 1, new_argv, new_colv);
+      }else{
+        zShellStatic = azArg[1];
+        sqlite3_exec(p->db,
+          "SELECT sql FROM "
+          "  (SELECT * FROM sqlite_master UNION ALL"
+          "   SELECT * FROM sqlite_temp_master) "
+          "WHERE tbl_name LIKE shellstatic() AND type!='meta' AND sql NOTNULL "
+          "ORDER BY substr(type,2,1), name",
+          callback, &data, &zErrMsg);
+        zShellStatic = 0;
+      }
+    }else{
+      sqlite3_exec(p->db,
+         "SELECT sql FROM "
+         "  (SELECT * FROM sqlite_master UNION ALL"
+         "   SELECT * FROM sqlite_temp_master) "
+         "WHERE type!='meta' AND sql NOTNULL AND name NOT LIKE 'sqlite_%'"
+         "ORDER BY substr(type,2,1), name",
+         callback, &data, &zErrMsg
+      );
+    }
+    if( zErrMsg ){
+      fprintf(stderr,"Error: %s\n", zErrMsg);
+      sqlite3_free(zErrMsg);
+    }
+  }else
+
+  if( c=='s' && strncmp(azArg[0], "separator", n)==0 && nArg==2 ){
+    sqlite3_snprintf(sizeof(p->separator), p->separator,
+                     "%.*s", (int)sizeof(p->separator)-1, azArg[1]);
+  }else
+
+  if( c=='s' && strncmp(azArg[0], "show", n)==0){
+    int i;
+    fprintf(p->out,"%9.9s: %s\n","echo", p->echoOn ? "on" : "off");
+    fprintf(p->out,"%9.9s: %s\n","explain", p->explainPrev.valid ? "on" :"off");
+    fprintf(p->out,"%9.9s: %s\n","headers", p->showHeader ? "on" : "off");
+    fprintf(p->out,"%9.9s: %s\n","mode", modeDescr[p->mode]);
+    fprintf(p->out,"%9.9s: ", "nullvalue");
+      output_c_string(p->out, p->nullvalue);
+      fprintf(p->out, "\n");
+    fprintf(p->out,"%9.9s: %s\n","output",
+                                 strlen(p->outfile) ? p->outfile : "stdout");
+    fprintf(p->out,"%9.9s: ", "separator");
+      output_c_string(p->out, p->separator);
+      fprintf(p->out, "\n");
+    fprintf(p->out,"%9.9s: ","width");
+    for (i=0;i<(int)ArraySize(p->colWidth) && p->colWidth[i] != 0;i++) {
+      fprintf(p->out,"%d ",p->colWidth[i]);
+    }
+    fprintf(p->out,"\n");
+  }else
+
+  if( c=='t' && n>1 && strncmp(azArg[0], "tables", n)==0 ){
+    char **azResult;
+    int nRow, rc;
+    char *zErrMsg;
+    open_db(p);
+    if( nArg==1 ){
+      rc = sqlite3_get_table(p->db,
+        "SELECT name FROM sqlite_master "
+        "WHERE type IN ('table','view') AND name NOT LIKE 'sqlite_%'"
+        "UNION ALL "
+        "SELECT name FROM sqlite_temp_master "
+        "WHERE type IN ('table','view') "
+        "ORDER BY 1",
+        &azResult, &nRow, 0, &zErrMsg
+      );
+    }else{
+      zShellStatic = azArg[1];
+      rc = sqlite3_get_table(p->db,
+        "SELECT name FROM sqlite_master "
+        "WHERE type IN ('table','view') AND name LIKE '%'||shellstatic()||'%' "
+        "UNION ALL "
+        "SELECT name FROM sqlite_temp_master "
+        "WHERE type IN ('table','view') AND name LIKE '%'||shellstatic()||'%' "
+        "ORDER BY 1",
+        &azResult, &nRow, 0, &zErrMsg
+      );
+      zShellStatic = 0;
+    }
+    if( zErrMsg ){
+      fprintf(stderr,"Error: %s\n", zErrMsg);
+      sqlite3_free(zErrMsg);
+    }
+    if( rc==SQLITE_OK ){
+      int len, maxlen = 0;
+      int i, j;
+      int nPrintCol, nPrintRow;
+      for(i=1; i<=nRow; i++){
+        if( azResult[i]==0 ) continue;
+        len = strlen(azResult[i]);
+        if( len>maxlen ) maxlen = len;
+      }
+      nPrintCol = 80/(maxlen+2);
+      if( nPrintCol<1 ) nPrintCol = 1;
+      nPrintRow = (nRow + nPrintCol - 1)/nPrintCol;
+      for(i=0; i<nPrintRow; i++){
+        for(j=i+1; j<=nRow; j+=nPrintRow){
+          char *zSp = j<=nPrintRow ? "" : "  ";
+          printf("%s%-*s", zSp, maxlen, azResult[j] ? azResult[j] : "");
+        }
+        printf("\n");
+      }
+    }else{
+      rc = 1;
+    }
+    sqlite3_free_table(azResult);
+  }else
+
+  if( c=='t' && n>4 && strncmp(azArg[0], "timeout", n)==0 && nArg>=2 ){
+    open_db(p);
+    sqlite3_busy_timeout(p->db, atoi(azArg[1]));
+  }else
+  
+#if HAS_TIMER  
+  if( c=='t' && n>=5 && strncmp(azArg[0], "timer", n)==0 && nArg>1 ){
+    enableTimer = booleanValue(azArg[1]);
+  }else
+#endif
+
+  if( c=='w' && strncmp(azArg[0], "width", n)==0 ){
+    int j;
+    assert( nArg<=ArraySize(azArg) );
+    for(j=1; j<nArg && j<ArraySize(p->colWidth); j++){
+      p->colWidth[j-1] = atoi(azArg[j]);
+    }
+  }else
+
+
+  {
+    fprintf(stderr, "unknown command or invalid arguments: "
+      " \"%s\". Enter \".help\" for help\n", azArg[0]);
+  }
+
+  return rc;
+}
+
+/*
+** Return TRUE if a semicolon occurs anywhere in the first N characters
+** of string z[].
+*/
+static int _contains_semicolon(const char *z, int N){
+  int i;
+  for(i=0; i<N; i++){  if( z[i]==';' ) return 1; }
+  return 0;
+}
+
+/*
+** Test to see if a line consists entirely of whitespace.
+*/
+static int _all_whitespace(const char *z){
+  for(; *z; z++){
+    if( isspace(*(unsigned char*)z) ) continue;
+    if( *z=='/' && z[1]=='*' ){
+      z += 2;
+      while( *z && (*z!='*' || z[1]!='/') ){ z++; }
+      if( *z==0 ) return 0;
+      z++;
+      continue;
+    }
+    if( *z=='-' && z[1]=='-' ){
+      z += 2;
+      while( *z && *z!='\n' ){ z++; }
+      if( *z==0 ) return 1;
+      continue;
+    }
+    return 0;
+  }
+  return 1;
+}
+
+/*
+** Return TRUE if the line typed in is an SQL command terminator other
+** than a semi-colon.  The SQL Server style "go" command is understood
+** as is the Oracle "/".
+*/
+static int _is_command_terminator(const char *zLine){
+  while( isspace(*(unsigned char*)zLine) ){ zLine++; };
+  if( zLine[0]=='/' && _all_whitespace(&zLine[1]) ) return 1;  /* Oracle */
+  if( tolower(zLine[0])=='g' && tolower(zLine[1])=='o'
+         && _all_whitespace(&zLine[2]) ){
+    return 1;  /* SQL Server */
+  }
+  return 0;
+}
+
+/*
+** Read input from *in and process it.  If *in==0 then input
+** is interactive - the user is typing it it.  Otherwise, input
+** is coming from a file or device.  A prompt is issued and history
+** is saved only if input is interactive.  An interrupt signal will
+** cause this routine to exit immediately, unless input is interactive.
+**
+** Return the number of errors.
+*/
+static int process_input(struct callback_data *p, FILE *in){
+  char *zLine = 0;
+  char *zSql = 0;
+  int nSql = 0;
+  int nSqlPrior = 0;
+  char *zErrMsg;
+  int rc;
+  int errCnt = 0;
+  int lineno = 0;
+  int startline = 0;
+
+  while( errCnt==0 || !bail_on_error || (in==0 && stdin_is_interactive) ){
+    fflush(p->out);
+    free(zLine);
+    zLine = one_input_line(zSql, in);
+    if( zLine==0 ){
+      break;  /* We have reached EOF */
+    }
+    if( seenInterrupt ){
+      if( in!=0 ) break;
+      seenInterrupt = 0;
+    }
+    lineno++;
+    if( p->echoOn ) printf("%s\n", zLine);
+    if( (zSql==0 || zSql[0]==0) && _all_whitespace(zLine) ) continue;
+    if( zLine && zLine[0]=='.' && nSql==0 ){
+      rc = do_meta_command(zLine, p);
+      if( rc==2 ){
+        break;
+      }else if( rc ){
+        errCnt++;
+      }
+      continue;
+    }
+    if( _is_command_terminator(zLine) ){
+      memcpy(zLine,";",2);
+    }
+    nSqlPrior = nSql;
+    if( zSql==0 ){
+      int i;
+      for(i=0; zLine[i] && isspace((unsigned char)zLine[i]); i++){}
+      if( zLine[i]!=0 ){
+        nSql = strlen(zLine);
+        zSql = malloc( nSql+1 );
+        if( zSql==0 ){
+          fprintf(stderr, "out of memory\n");
+          exit(1);
+        }
+        memcpy(zSql, zLine, nSql+1);
+        startline = lineno;
+      }
+    }else{
+      int len = strlen(zLine);
+      zSql = realloc( zSql, nSql + len + 2 );
+      if( zSql==0 ){
+        fprintf(stderr,"%s: out of memory!\n", Argv0);
+        exit(1);
+      }
+      zSql[nSql++] = '\n';
+      memcpy(&zSql[nSql], zLine, len+1);
+      nSql += len;
+    }
+    if( zSql && _contains_semicolon(&zSql[nSqlPrior], nSql-nSqlPrior)
+                && sqlite3_complete(zSql) ){
+      p->cnt = 0;
+      open_db(p);
+      BEGIN_TIMER;
+      rc = sqlite3_exec(p->db, zSql, callback, p, &zErrMsg);
+      END_TIMER;
+      if( rc || zErrMsg ){
+        char zPrefix[100];
+        if( in!=0 || !stdin_is_interactive ){
+          sqlite3_snprintf(sizeof(zPrefix), zPrefix, 
+                           "SQL error near line %d:", startline);
+        }else{
+          sqlite3_snprintf(sizeof(zPrefix), zPrefix, "SQL error:");
+        }
+        if( zErrMsg!=0 ){
+          printf("%s %s\n", zPrefix, zErrMsg);
+          sqlite3_free(zErrMsg);
+          zErrMsg = 0;
+        }else{
+          printf("%s %s\n", zPrefix, sqlite3_errmsg(p->db));
+        }
+        errCnt++;
+      }
+      free(zSql);
+      zSql = 0;
+      nSql = 0;
+    }
+  }
+  if( zSql ){
+    if( !_all_whitespace(zSql) ) printf("Incomplete SQL: %s\n", zSql);
+    free(zSql);
+  }
+  free(zLine);
+  return errCnt;
+}
+
+/*
+** Return a pathname which is the user's home directory.  A
+** 0 return indicates an error of some kind.  Space to hold the
+** resulting string is obtained from malloc().  The calling
+** function should free the result.
+*/
+static char *find_home_dir(void){
+  char *home_dir = NULL;
+
+#if !defined(_WIN32) && !defined(WIN32) && !defined(__OS2__) && !defined(_WIN32_WCE)
+  struct passwd *pwent;
+  uid_t uid = getuid();
+  if( (pwent=getpwuid(uid)) != NULL) {
+    home_dir = pwent->pw_dir;
+  }
+#endif
+
+#if defined(_WIN32_WCE)
+  /* Windows CE (arm-wince-mingw32ce-gcc) does not provide getenv()
+   */
+  home_dir = strdup("/");
+#else
+
+#if defined(_WIN32) || defined(WIN32) || defined(__OS2__)
+  if (!home_dir) {
+    home_dir = getenv("USERPROFILE");
+  }
+#endif
+
+  if (!home_dir) {
+    home_dir = getenv("HOME");
+  }
+
+#if defined(_WIN32) || defined(WIN32) || defined(__OS2__)
+  if (!home_dir) {
+    char *zDrive, *zPath;
+    int n;
+    zDrive = getenv("HOMEDRIVE");
+    zPath = getenv("HOMEPATH");
+    if( zDrive && zPath ){
+      n = strlen(zDrive) + strlen(zPath) + 1;
+      home_dir = malloc( n );
+      if( home_dir==0 ) return 0;
+      sqlite3_snprintf(n, home_dir, "%s%s", zDrive, zPath);
+      return home_dir;
+    }
+    home_dir = "c:\\";
+  }
+#endif
+
+#endif /* !_WIN32_WCE */
+
+  if( home_dir ){
+    int n = strlen(home_dir) + 1;
+    char *z = malloc( n );
+    if( z ) memcpy(z, home_dir, n);
+    home_dir = z;
+  }
+
+  return home_dir;
+}
+
+/*
+** Read input from the file given by sqliterc_override.  Or if that
+** parameter is NULL, take input from ~/.sqliterc
+*/
+static void process_sqliterc(
+  struct callback_data *p,        /* Configuration data */
+  const char *sqliterc_override   /* Name of config file. NULL to use default */
+){
+  char *home_dir = NULL;
+  const char *sqliterc = sqliterc_override;
+  char *zBuf = 0;
+  FILE *in = NULL;
+  int nBuf;
+
+  if (sqliterc == NULL) {
+    home_dir = find_home_dir();
+    if( home_dir==0 ){
+      fprintf(stderr,"%s: cannot locate your home directory!\n", Argv0);
+      return;
+    }
+    nBuf = strlen(home_dir) + 16;
+    zBuf = malloc( nBuf );
+    if( zBuf==0 ){
+      fprintf(stderr,"%s: out of memory!\n", Argv0);
+      exit(1);
+    }
+    sqlite3_snprintf(nBuf, zBuf,"%s/.sqliterc",home_dir);
+    free(home_dir);
+    sqliterc = (const char*)zBuf;
+  }
+  in = fopen(sqliterc,"rb");
+  if( in ){
+    if( stdin_is_interactive ){
+      printf("-- Loading resources from %s\n",sqliterc);
+    }
+    process_input(p,in);
+    fclose(in);
+  }
+  free(zBuf);
+  return;
+}
+
+/*
+** Show available command line options
+*/
+static const char zOptions[] = 
+  "   -init filename       read/process named file\n"
+  "   -echo                print commands before execution\n"
+  "   -[no]header          turn headers on or off\n"
+  "   -bail                stop after hitting an error\n"
+  "   -interactive         force interactive I/O\n"
+  "   -batch               force batch I/O\n"
+  "   -column              set output mode to 'column'\n"
+  "   -csv                 set output mode to 'csv'\n"
+  "   -html                set output mode to HTML\n"
+  "   -line                set output mode to 'line'\n"
+  "   -list                set output mode to 'list'\n"
+  "   -separator 'x'       set output field separator (|)\n"
+  "   -nullvalue 'text'    set text string for NULL values\n"
+  "   -version             show SQLite version\n"
+;
+static void usage(int showDetail){
+  fprintf(stderr,
+      "Usage: %s [OPTIONS] FILENAME [SQL]\n"  
+      "FILENAME is the name of an SQLite database. A new database is created\n"
+      "if the file does not previously exist.\n", Argv0);
+  if( showDetail ){
+    fprintf(stderr, "OPTIONS include:\n%s", zOptions);
+  }else{
+    fprintf(stderr, "Use the -help option for additional information\n");
+  }
+  exit(1);
+}
+
+/*
+** Initialize the state information in data
+*/
+static void main_init(struct callback_data *data) {
+  memset(data, 0, sizeof(*data));
+  data->mode = MODE_List;
+  memcpy(data->separator,"|", 2);
+  data->showHeader = 0;
+  sqlite3_snprintf(sizeof(mainPrompt), mainPrompt,"sqlite> ");
+  sqlite3_snprintf(sizeof(continuePrompt), continuePrompt,"   ...> ");
+}
+
+int main(int argc, char **argv){
+  char *zErrMsg = 0;
+  struct callback_data data;
+  const char *zInitFile = 0;
+  char *zFirstCmd = 0;
+  int i;
+  int rc = 0;
+
+  /* Begin evanm patch. */
+#ifdef SQLITE_GEARS_DISABLE_SHELL_ICU
+  /* Gears doesn't use this. */
+#else
+  extern int sqlite_shell_init_icu();
+  if( !sqlite_shell_init_icu() ){
+    fprintf(stderr, "%s: warning: couldn't find icudt38.dll; "
+                    "queries against ICU FTS tables will fail.\n", argv[0]);
+  }
+#endif
+  /* End evanm patch. */
+
+  Argv0 = argv[0];
+  main_init(&data);
+  stdin_is_interactive = isatty(0);
+
+  /* Make sure we have a valid signal handler early, before anything
+  ** else is done.
+  */
+#ifdef SIGINT
+  signal(SIGINT, interrupt_handler);
+#endif
+
+  /* Do an initial pass through the command-line argument to locate
+  ** the name of the database file, the name of the initialization file,
+  ** and the first command to execute.
+  */
+  for(i=1; i<argc-1; i++){
+    char *z;
+    if( argv[i][0]!='-' ) break;
+    z = argv[i];
+    if( z[0]=='-' && z[1]=='-' ) z++;
+    if( strcmp(argv[i],"-separator")==0 || strcmp(argv[i],"-nullvalue")==0 ){
+      i++;
+    }else if( strcmp(argv[i],"-init")==0 ){
+      i++;
+      zInitFile = argv[i];
+    }
+  }
+  if( i<argc ){
+#if defined(SQLITE_OS_OS2) && SQLITE_OS_OS2
+    data.zDbFilename = (const char *)convertCpPathToUtf8( argv[i++] );
+#else
+    data.zDbFilename = argv[i++];
+#endif
+  }else{
+#ifndef SQLITE_OMIT_MEMORYDB
+    data.zDbFilename = ":memory:";
+#else
+    data.zDbFilename = 0;
+#endif
+  }
+  if( i<argc ){
+    zFirstCmd = argv[i++];
+  }
+  data.out = stdout;
+
+#ifdef SQLITE_OMIT_MEMORYDB
+  if( data.zDbFilename==0 ){
+    fprintf(stderr,"%s: no database filename specified\n", argv[0]);
+    exit(1);
+  }
+#endif
+
+  /* Go ahead and open the database file if it already exists.  If the
+  ** file does not exist, delay opening it.  This prevents empty database
+  ** files from being created if a user mistypes the database name argument
+  ** to the sqlite command-line tool.
+  */
+  if( access(data.zDbFilename, 0)==0 ){
+    open_db(&data);
+  }
+
+  /* Process the initialization file if there is one.  If no -init option
+  ** is given on the command line, look for a file named ~/.sqliterc and
+  ** try to process it.
+  */
+  process_sqliterc(&data,zInitFile);
+
+  /* Make a second pass through the command-line argument and set
+  ** options.  This second pass is delayed until after the initialization
+  ** file is processed so that the command-line arguments will override
+  ** settings in the initialization file.
+  */
+  for(i=1; i<argc && argv[i][0]=='-'; i++){
+    char *z = argv[i];
+    if( z[1]=='-' ){ z++; }
+    if( strcmp(z,"-init")==0 ){
+      i++;
+    }else if( strcmp(z,"-html")==0 ){
+      data.mode = MODE_Html;
+    }else if( strcmp(z,"-list")==0 ){
+      data.mode = MODE_List;
+    }else if( strcmp(z,"-line")==0 ){
+      data.mode = MODE_Line;
+    }else if( strcmp(z,"-column")==0 ){
+      data.mode = MODE_Column;
+    }else if( strcmp(z,"-csv")==0 ){
+      data.mode = MODE_Csv;
+      memcpy(data.separator,",",2);
+    }else if( strcmp(z,"-separator")==0 ){
+      i++;
+      sqlite3_snprintf(sizeof(data.separator), data.separator,
+                       "%.*s",(int)sizeof(data.separator)-1,argv[i]);
+    }else if( strcmp(z,"-nullvalue")==0 ){
+      i++;
+      sqlite3_snprintf(sizeof(data.nullvalue), data.nullvalue,
+                       "%.*s",(int)sizeof(data.nullvalue)-1,argv[i]);
+    }else if( strcmp(z,"-header")==0 ){
+      data.showHeader = 1;
+    }else if( strcmp(z,"-noheader")==0 ){
+      data.showHeader = 0;
+    }else if( strcmp(z,"-echo")==0 ){
+      data.echoOn = 1;
+    }else if( strcmp(z,"-bail")==0 ){
+      bail_on_error = 1;
+    }else if( strcmp(z,"-version")==0 ){
+      printf("%s\n", sqlite3_libversion());
+      return 0;
+    }else if( strcmp(z,"-interactive")==0 ){
+      stdin_is_interactive = 1;
+    }else if( strcmp(z,"-batch")==0 ){
+      stdin_is_interactive = 0;
+    }else if( strcmp(z,"-help")==0 || strcmp(z, "--help")==0 ){
+      usage(1);
+    }else{
+      fprintf(stderr,"%s: unknown option: %s\n", Argv0, z);
+      fprintf(stderr,"Use -help for a list of options.\n");
+      return 1;
+    }
+  }
+
+  if( zFirstCmd ){
+    /* Run just the command that follows the database name
+    */
+    if( zFirstCmd[0]=='.' ){
+      do_meta_command(zFirstCmd, &data);
+      exit(0);
+    }else{
+      int rc;
+      open_db(&data);
+      rc = sqlite3_exec(data.db, zFirstCmd, callback, &data, &zErrMsg);
+      if( rc!=0 && zErrMsg!=0 ){
+        fprintf(stderr,"SQL error: %s\n", zErrMsg);
+        exit(1);
+      }
+    }
+  }else{
+    /* Run commands received from standard input
+    */
+    if( stdin_is_interactive ){
+      char *zHome;
+      char *zHistory = 0;
+      int nHistory;
+      printf(
+        "SQLite version %s\n"
+        "Enter \".help\" for instructions\n"
+        "Enter SQL statements terminated with a \";\"\n",
+        sqlite3_libversion()
+      );
+      zHome = find_home_dir();
+      if( zHome && (zHistory = malloc(nHistory = strlen(zHome)+20))!=0 ){
+        sqlite3_snprintf(nHistory, zHistory,"%s/.sqlite_history", zHome);
+      }
+#if defined(HAVE_READLINE) && HAVE_READLINE==1
+      if( zHistory ) read_history(zHistory);
+#endif
+      rc = process_input(&data, 0);
+      if( zHistory ){
+        stifle_history(100);
+        write_history(zHistory);
+        free(zHistory);
+      }
+      free(zHome);
+    }else{
+      rc = process_input(&data, stdin);
+    }
+  }
+  set_table_name(&data, 0);
+  if( db ){
+    if( sqlite3_close(db)!=SQLITE_OK ){
+      fprintf(stderr,"error closing database: %s\n", sqlite3_errmsg(db));
+    }
+  }
+  return rc;
+}
diff --git a/third_party/sqlite/src/shell_icu.c b/third_party/sqlite/src/shell_icu.c
new file mode 100755
index 0000000..d68cf8f
--- /dev/null
+++ b/third_party/sqlite/src/shell_icu.c
@@ -0,0 +1,29 @@
+/* Copyright 2007 Google Inc. All Rights Reserved.
+**/
+
+#include <windows.h>
+#include "unicode/udata.h"
+
+/*
+** This function attempts to load the ICU data tables from a DLL.
+** Returns 0 on failure, nonzero on success.
+** This a hack job of icu_utils.cc:Initialize().  It's Chrome-specific code.
+*/
+int sqlite_shell_init_icu() {
+  HMODULE module;
+  FARPROC addr;
+  UErrorCode err;
+  
+  module = LoadLibrary(L"icudt38.dll");
+  if (!module)
+    return 0;
+
+  addr = GetProcAddress(module, "icudt38_dat");
+  if (!addr)
+    return 0;
+
+  err = U_ZERO_ERROR;
+  udata_setCommonData(addr, &err);
+
+  return 1;
+}
diff --git a/third_party/sqlite/src/sqlite.h.in b/third_party/sqlite/src/sqlite.h.in
new file mode 100755
index 0000000..d37b251
--- /dev/null
+++ b/third_party/sqlite/src/sqlite.h.in
@@ -0,0 +1,6294 @@
+/*

+** 2001 September 15

+**

+** The author disclaims copyright to this source code.  In place of

+** a legal notice, here is a blessing:

+**

+**    May you do good and not evil.

+**    May you find forgiveness for yourself and forgive others.

+**    May you share freely, never taking more than you give.

+**

+*************************************************************************

+** This header file defines the interface that the SQLite library

+** presents to client programs.  If a C-function, structure, datatype,

+** or constant definition does not appear in this file, then it is

+** not a published API of SQLite, is subject to change without

+** notice, and should not be referenced by programs that use SQLite.

+**

+** Some of the definitions that are in this file are marked as

+** "experimental".  Experimental interfaces are normally new

+** features recently added to SQLite.  We do not anticipate changes

+** to experimental interfaces but reserve to make minor changes if

+** experience from use "in the wild" suggest such changes are prudent.

+**

+** The official C-language API documentation for SQLite is derived

+** from comments in this file.  This file is the authoritative source

+** on how SQLite interfaces are suppose to operate.

+**

+** The name of this file under configuration management is "sqlite.h.in".

+** The makefile makes some minor changes to this file (such as inserting

+** the version number) and changes its name to "sqlite3.h" as

+** part of the build process.

+**

+** @(#) $Id: sqlite.h.in,v 1.388 2008/08/06 13:40:13 danielk1977 Exp $

+*/

+#ifndef _SQLITE3_H_

+#define _SQLITE3_H_

+#include <stdarg.h>     /* Needed for the definition of va_list */

+

+/*

+** Make sure we can call this stuff from C++.

+*/

+#ifdef __cplusplus

+extern "C" {

+#endif

+

+

+/*

+** Add the ability to override 'extern'

+*/

+#ifndef SQLITE_EXTERN

+# define SQLITE_EXTERN extern

+#endif

+

+/*

+** Ensure these symbols were not defined by some previous header file.

+*/

+#ifdef SQLITE_VERSION

+# undef SQLITE_VERSION

+#endif

+#ifdef SQLITE_VERSION_NUMBER

+# undef SQLITE_VERSION_NUMBER

+#endif

+

+/*

+** CAPI3REF: Compile-Time Library Version Numbers {H10010} <S60100>

+**

+** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in

+** the sqlite3.h file specify the version of SQLite with which

+** that header file is associated.

+**

+** The "version" of SQLite is a string of the form "X.Y.Z".

+** The phrase "alpha" or "beta" might be appended after the Z.

+** The X value is major version number always 3 in SQLite3.

+** The X value only changes when backwards compatibility is

+** broken and we intend to never break backwards compatibility.

+** The Y value is the minor version number and only changes when

+** there are major feature enhancements that are forwards compatible

+** but not backwards compatible.

+** The Z value is the release number and is incremented with

+** each release but resets back to 0 whenever Y is incremented.

+**

+** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()].

+**

+** INVARIANTS:

+**

+** {H10011} The SQLITE_VERSION #define in the sqlite3.h header file shall

+**          evaluate to a string literal that is the SQLite version

+**          with which the header file is associated.

+**

+** {H10014} The SQLITE_VERSION_NUMBER #define shall resolve to an integer

+**          with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z

+**          are the major version, minor version, and release number.

+*/

+#define SQLITE_VERSION         "--VERS--"

+#define SQLITE_VERSION_NUMBER  --VERSION-NUMBER--

+

+/*

+** CAPI3REF: Run-Time Library Version Numbers {H10020} <S60100>

+** KEYWORDS: sqlite3_version

+**

+** These features provide the same information as the [SQLITE_VERSION]

+** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated

+** with the library instead of the header file.  Cautious programmers might

+** include a check in their application to verify that

+** sqlite3_libversion_number() always returns the value

+** [SQLITE_VERSION_NUMBER].

+**

+** The sqlite3_libversion() function returns the same information as is

+** in the sqlite3_version[] string constant.  The function is provided

+** for use in DLLs since DLL users usually do not have direct access to string

+** constants within the DLL.

+**

+** INVARIANTS:

+**

+** {H10021} The [sqlite3_libversion_number()] interface shall return

+**          an integer equal to [SQLITE_VERSION_NUMBER].

+**

+** {H10022} The [sqlite3_version] string constant shall contain

+**          the text of the [SQLITE_VERSION] string.

+**

+** {H10023} The [sqlite3_libversion()] function shall return

+**          a pointer to the [sqlite3_version] string constant.

+*/

+SQLITE_EXTERN const char sqlite3_version[];

+const char *sqlite3_libversion(void);

+int sqlite3_libversion_number(void);

+

+/*

+** CAPI3REF: Test To See If The Library Is Threadsafe {H10100} <S60100>

+**

+** SQLite can be compiled with or without mutexes.  When

+** the [SQLITE_THREADSAFE] C preprocessor macro is true, mutexes

+** are enabled and SQLite is threadsafe.  When that macro is false,

+** the mutexes are omitted.  Without the mutexes, it is not safe

+** to use SQLite concurrently from more than one thread.

+**

+** Enabling mutexes incurs a measurable performance penalty.

+** So if speed is of utmost importance, it makes sense to disable

+** the mutexes.  But for maximum safety, mutexes should be enabled.

+** The default behavior is for mutexes to be enabled.

+**

+** This interface can be used by a program to make sure that the

+** version of SQLite that it is linking against was compiled with

+** the desired setting of the [SQLITE_THREADSAFE] macro.

+**

+** This interface only reports on the compile-time mutex setting

+** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with

+** SQLITE_THREADSAFE=1 then mutexes are enabled by default but

+** can be fully or partially disabled using a call to [sqlite3_config()]

+** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],

+** or [SQLITE_CONFIG_MUTEX].  The return value of this function shows

+** only the default compile-time setting, not any run-time changes

+** to that setting.

+**

+** INVARIANTS:

+**

+** {H10101} The [sqlite3_threadsafe()] function shall return nonzero if

+**          SQLite was compiled with the its mutexes enabled by default

+**          or zero if SQLite was compiled such that mutexes are

+**          permanently disabled.

+**

+** {H10102} The value returned by the [sqlite3_threadsafe()] function

+**          shall not change when mutex setting are modified at

+**          runtime using the [sqlite3_config()] interface and 

+**          especially the [SQLITE_CONFIG_SINGLETHREAD],

+**          [SQLITE_CONFIG_MULTITHREAD], [SQLITE_CONFIG_SERIALIZED],

+**          and [SQLITE_CONFIG_MUTEX] verbs.

+*/

+int sqlite3_threadsafe(void);

+

+/*

+** CAPI3REF: Database Connection Handle {H12000} <S40200>

+** KEYWORDS: {database connection} {database connections}

+**

+** Each open SQLite database is represented by a pointer to an instance of

+** the opaque structure named "sqlite3".  It is useful to think of an sqlite3

+** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and

+** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]

+** is its destructor.  There are many other interfaces (such as

+** [sqlite3_prepare_v2()], [sqlite3_create_function()], and

+** [sqlite3_busy_timeout()] to name but three) that are methods on an

+** sqlite3 object.

+*/

+typedef struct sqlite3 sqlite3;

+

+/*

+** CAPI3REF: 64-Bit Integer Types {H10200} <S10110>

+** KEYWORDS: sqlite_int64 sqlite_uint64

+**

+** Because there is no cross-platform way to specify 64-bit integer types

+** SQLite includes typedefs for 64-bit signed and unsigned integers.

+**

+** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.

+** The sqlite_int64 and sqlite_uint64 types are supported for backwards

+** compatibility only.

+**

+** INVARIANTS:

+**

+** {H10201} The [sqlite_int64] and [sqlite3_int64] type shall specify

+**          a 64-bit signed integer.

+**

+** {H10202} The [sqlite_uint64] and [sqlite3_uint64] type shall specify

+**          a 64-bit unsigned integer.

+*/

+#ifdef SQLITE_INT64_TYPE

+  typedef SQLITE_INT64_TYPE sqlite_int64;

+  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;

+#elif defined(_MSC_VER) || defined(__BORLANDC__)

+  typedef __int64 sqlite_int64;

+  typedef unsigned __int64 sqlite_uint64;

+#else

+  typedef long long int sqlite_int64;

+  typedef unsigned long long int sqlite_uint64;

+#endif

+typedef sqlite_int64 sqlite3_int64;

+typedef sqlite_uint64 sqlite3_uint64;

+

+/*

+** If compiling for a processor that lacks floating point support,

+** substitute integer for floating-point.

+*/

+#ifdef SQLITE_OMIT_FLOATING_POINT

+# define double sqlite3_int64

+#endif

+

+/*

+** CAPI3REF: Closing A Database Connection {H12010} <S30100><S40200>

+**

+** This routine is the destructor for the [sqlite3] object.

+**

+** Applications should [sqlite3_finalize | finalize] all [prepared statements]

+** and [sqlite3_blob_close | close] all [BLOB handles] associated with

+** the [sqlite3] object prior to attempting to close the object.

+** The [sqlite3_next_stmt()] interface can be used to locate all

+** [prepared statements] associated with a [database connection] if desired.

+** Typical code might look like this:

+**

+** <blockquote><pre>

+** sqlite3_stmt *pStmt;

+** while( (pStmt = sqlite3_next_stmt(db, 0))!=0 ){

+** &nbsp;   sqlite3_finalize(pStmt);

+** }

+** </pre></blockquote>

+**

+** If [sqlite3_close()] is invoked while a transaction is open,

+** the transaction is automatically rolled back.

+**

+** INVARIANTS:

+**

+** {H12011} A successful call to [sqlite3_close(C)] shall destroy the

+**          [database connection] object C.

+**

+** {H12012} A successful call to [sqlite3_close(C)] shall return SQLITE_OK.

+**

+** {H12013} A successful call to [sqlite3_close(C)] shall release all

+**          memory and system resources associated with [database connection]

+**          C.

+**

+** {H12014} A call to [sqlite3_close(C)] on a [database connection] C that

+**          has one or more open [prepared statements] shall fail with

+**          an [SQLITE_BUSY] error code.

+**

+** {H12015} A call to [sqlite3_close(C)] where C is a NULL pointer shall

+**          return SQLITE_OK.

+**

+** {H12019} When [sqlite3_close(C)] is invoked on a [database connection] C

+**          that has a pending transaction, the transaction shall be

+**          rolled back.

+**

+** ASSUMPTIONS:

+**

+** {A12016} The C parameter to [sqlite3_close(C)] must be either a NULL

+**          pointer or an [sqlite3] object pointer obtained

+**          from [sqlite3_open()], [sqlite3_open16()], or

+**          [sqlite3_open_v2()], and not previously closed.

+*/

+int sqlite3_close(sqlite3 *);

+

+/*

+** The type for a callback function.

+** This is legacy and deprecated.  It is included for historical

+** compatibility and is not documented.

+*/

+typedef int (*sqlite3_callback)(void*,int,char**, char**);

+

+/*

+** CAPI3REF: One-Step Query Execution Interface {H12100} <S10000>

+**

+** The sqlite3_exec() interface is a convenient way of running one or more

+** SQL statements without having to write a lot of C code.  The UTF-8 encoded

+** SQL statements are passed in as the second parameter to sqlite3_exec().

+** The statements are evaluated one by one until either an error or

+** an interrupt is encountered, or until they are all done.  The 3rd parameter

+** is an optional callback that is invoked once for each row of any query

+** results produced by the SQL statements.  The 5th parameter tells where

+** to write any error messages.

+**

+** The error message passed back through the 5th parameter is held

+** in memory obtained from [sqlite3_malloc()].  To avoid a memory leak,

+** the calling application should call [sqlite3_free()] on any error

+** message returned through the 5th parameter when it has finished using

+** the error message.

+**

+** If the SQL statement in the 2nd parameter is NULL or an empty string

+** or a string containing only whitespace and comments, then no SQL

+** statements are evaluated and the database is not changed.

+**

+** The sqlite3_exec() interface is implemented in terms of

+** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()].

+** The sqlite3_exec() routine does nothing to the database that cannot be done

+** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()].

+**

+** INVARIANTS:

+**

+** {H12101} A successful invocation of [sqlite3_exec(D,S,C,A,E)]

+**          shall sequentially evaluate all of the UTF-8 encoded,

+**          semicolon-separated SQL statements in the zero-terminated

+**          string S within the context of the [database connection] D.

+**

+** {H12102} If the S parameter to [sqlite3_exec(D,S,C,A,E)] is NULL then

+**          the actions of the interface shall be the same as if the

+**          S parameter were an empty string.

+**

+** {H12104} The return value of [sqlite3_exec()] shall be [SQLITE_OK] if all

+**          SQL statements run successfully and to completion.

+**

+** {H12105} The return value of [sqlite3_exec()] shall be an appropriate

+**          non-zero [error code] if any SQL statement fails.

+**

+** {H12107} If one or more of the SQL statements handed to [sqlite3_exec()]

+**          return results and the 3rd parameter is not NULL, then

+**          the callback function specified by the 3rd parameter shall be

+**          invoked once for each row of result.

+**

+** {H12110} If the callback returns a non-zero value then [sqlite3_exec()]

+**          shall abort the SQL statement it is currently evaluating,

+**          skip all subsequent SQL statements, and return [SQLITE_ABORT].

+**

+** {H12113} The [sqlite3_exec()] routine shall pass its 4th parameter through

+**          as the 1st parameter of the callback.

+**

+** {H12116} The [sqlite3_exec()] routine shall set the 2nd parameter of its

+**          callback to be the number of columns in the current row of

+**          result.

+**

+** {H12119} The [sqlite3_exec()] routine shall set the 3rd parameter of its

+**          callback to be an array of pointers to strings holding the

+**          values for each column in the current result set row as

+**          obtained from [sqlite3_column_text()].

+**

+** {H12122} The [sqlite3_exec()] routine shall set the 4th parameter of its

+**          callback to be an array of pointers to strings holding the

+**          names of result columns as obtained from [sqlite3_column_name()].

+**

+** {H12125} If the 3rd parameter to [sqlite3_exec()] is NULL then

+**          [sqlite3_exec()] shall silently discard query results.

+**

+** {H12131} If an error occurs while parsing or evaluating any of the SQL

+**          statements in the S parameter of [sqlite3_exec(D,S,C,A,E)] and if

+**          the E parameter is not NULL, then [sqlite3_exec()] shall store

+**          in *E an appropriate error message written into memory obtained

+**          from [sqlite3_malloc()].

+**

+** {H12134} The [sqlite3_exec(D,S,C,A,E)] routine shall set the value of

+**          *E to NULL if E is not NULL and there are no errors.

+**

+** {H12137} The [sqlite3_exec(D,S,C,A,E)] function shall set the [error code]

+**          and message accessible via [sqlite3_errcode()],

+**          [sqlite3_errmsg()], and [sqlite3_errmsg16()].

+**

+** {H12138} If the S parameter to [sqlite3_exec(D,S,C,A,E)] is NULL or an

+**          empty string or contains nothing other than whitespace, comments,

+**          and/or semicolons, then results of [sqlite3_errcode()],

+**          [sqlite3_errmsg()], and [sqlite3_errmsg16()]

+**          shall reset to indicate no errors.

+**

+** ASSUMPTIONS:

+**

+** {A12141} The first parameter to [sqlite3_exec()] must be an valid and open

+**          [database connection].

+**

+** {A12142} The database connection must not be closed while

+**          [sqlite3_exec()] is running.

+**

+** {A12143} The calling function should use [sqlite3_free()] to free

+**          the memory that *errmsg is left pointing at once the error

+**          message is no longer needed.

+**

+** {A12145} The SQL statement text in the 2nd parameter to [sqlite3_exec()]

+**          must remain unchanged while [sqlite3_exec()] is running.

+*/

+int sqlite3_exec(

+  sqlite3*,                                  /* An open database */

+  const char *sql,                           /* SQL to be evaluated */

+  int (*callback)(void*,int,char**,char**),  /* Callback function */

+  void *,                                    /* 1st argument to callback */

+  char **errmsg                              /* Error msg written here */

+);

+

+/*

+** CAPI3REF: Result Codes {H10210} <S10700>

+** KEYWORDS: SQLITE_OK {error code} {error codes}

+** KEYWORDS: {result code} {result codes}

+**

+** Many SQLite functions return an integer result code from the set shown

+** here in order to indicates success or failure.

+**

+** New error codes may be added in future versions of SQLite.

+**

+** See also: [SQLITE_IOERR_READ | extended result codes]

+*/

+#define SQLITE_OK           0   /* Successful result */

+/* beginning-of-error-codes */

+#define SQLITE_ERROR        1   /* SQL error or missing database */

+#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */

+#define SQLITE_PERM         3   /* Access permission denied */

+#define SQLITE_ABORT        4   /* Callback routine requested an abort */

+#define SQLITE_BUSY         5   /* The database file is locked */

+#define SQLITE_LOCKED       6   /* A table in the database is locked */

+#define SQLITE_NOMEM        7   /* A malloc() failed */

+#define SQLITE_READONLY     8   /* Attempt to write a readonly database */

+#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/

+#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */

+#define SQLITE_CORRUPT     11   /* The database disk image is malformed */

+#define SQLITE_NOTFOUND    12   /* NOT USED. Table or record not found */

+#define SQLITE_FULL        13   /* Insertion failed because database is full */

+#define SQLITE_CANTOPEN    14   /* Unable to open the database file */

+#define SQLITE_PROTOCOL    15   /* NOT USED. Database lock protocol error */

+#define SQLITE_EMPTY       16   /* Database is empty */

+#define SQLITE_SCHEMA      17   /* The database schema changed */

+#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */

+#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */

+#define SQLITE_MISMATCH    20   /* Data type mismatch */

+#define SQLITE_MISUSE      21   /* Library used incorrectly */

+#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */

+#define SQLITE_AUTH        23   /* Authorization denied */

+#define SQLITE_FORMAT      24   /* Auxiliary database format error */

+#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */

+#define SQLITE_NOTADB      26   /* File opened that is not a database file */

+#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */

+#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */

+/* end-of-error-codes */

+

+/*

+** CAPI3REF: Extended Result Codes {H10220} <S10700>

+** KEYWORDS: {extended error code} {extended error codes}

+** KEYWORDS: {extended result code} {extended result codes}

+**

+** In its default configuration, SQLite API routines return one of 26 integer

+** [SQLITE_OK | result codes].  However, experience has shown that many of

+** these result codes are too coarse-grained.  They do not provide as

+** much information about problems as programmers might like.  In an effort to

+** address this, newer versions of SQLite (version 3.3.8 and later) include

+** support for additional result codes that provide more detailed information

+** about errors. The extended result codes are enabled or disabled

+** on a per database connection basis using the

+** [sqlite3_extended_result_codes()] API.

+**

+** Some of the available extended result codes are listed here.

+** One may expect the number of extended result codes will be expand

+** over time.  Software that uses extended result codes should expect

+** to see new result codes in future releases of SQLite.

+**

+** The SQLITE_OK result code will never be extended.  It will always

+** be exactly zero.

+**

+** INVARIANTS:

+**

+** {H10223} The symbolic name for an extended result code shall contains

+**          a related primary result code as a prefix.

+**

+** {H10224} Primary result code names shall contain a single "_" character.

+**

+** {H10225} Extended result code names shall contain two or more "_" characters.

+**

+** {H10226} The numeric value of an extended result code shall contain the

+**          numeric value of its corresponding primary result code in

+**          its least significant 8 bits.

+*/

+#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))

+#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))

+#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))

+#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))

+#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))

+#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))

+#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))

+#define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))

+#define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))

+#define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))

+#define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))

+#define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))

+#define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))

+#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))

+

+/*

+** CAPI3REF: Flags For File Open Operations {H10230} <H11120> <H12700>

+**

+** These bit values are intended for use in the

+** 3rd parameter to the [sqlite3_open_v2()] interface and

+** in the 4th parameter to the xOpen method of the

+** [sqlite3_vfs] object.

+*/

+#define SQLITE_OPEN_READONLY         0x00000001

+#define SQLITE_OPEN_READWRITE        0x00000002

+#define SQLITE_OPEN_CREATE           0x00000004

+#define SQLITE_OPEN_DELETEONCLOSE    0x00000008

+#define SQLITE_OPEN_EXCLUSIVE        0x00000010

+#define SQLITE_OPEN_MAIN_DB          0x00000100

+#define SQLITE_OPEN_TEMP_DB          0x00000200

+#define SQLITE_OPEN_TRANSIENT_DB     0x00000400

+#define SQLITE_OPEN_MAIN_JOURNAL     0x00000800

+#define SQLITE_OPEN_TEMP_JOURNAL     0x00001000

+#define SQLITE_OPEN_SUBJOURNAL       0x00002000

+#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000

+#define SQLITE_OPEN_NOMUTEX          0x00008000

+

+/*

+** CAPI3REF: Device Characteristics {H10240} <H11120>

+**

+** The xDeviceCapabilities method of the [sqlite3_io_methods]

+** object returns an integer which is a vector of the these

+** bit values expressing I/O characteristics of the mass storage

+** device that holds the file that the [sqlite3_io_methods]

+** refers to.

+**

+** The SQLITE_IOCAP_ATOMIC property means that all writes of

+** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values

+** mean that writes of blocks that are nnn bytes in size and

+** are aligned to an address which is an integer multiple of

+** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means

+** that when data is appended to a file, the data is appended

+** first then the size of the file is extended, never the other

+** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that

+** information is written to disk in the same order as calls

+** to xWrite().

+*/

+#define SQLITE_IOCAP_ATOMIC          0x00000001

+#define SQLITE_IOCAP_ATOMIC512       0x00000002

+#define SQLITE_IOCAP_ATOMIC1K        0x00000004

+#define SQLITE_IOCAP_ATOMIC2K        0x00000008

+#define SQLITE_IOCAP_ATOMIC4K        0x00000010

+#define SQLITE_IOCAP_ATOMIC8K        0x00000020

+#define SQLITE_IOCAP_ATOMIC16K       0x00000040

+#define SQLITE_IOCAP_ATOMIC32K       0x00000080

+#define SQLITE_IOCAP_ATOMIC64K       0x00000100

+#define SQLITE_IOCAP_SAFE_APPEND     0x00000200

+#define SQLITE_IOCAP_SEQUENTIAL      0x00000400

+

+/*

+** CAPI3REF: File Locking Levels {H10250} <H11120> <H11310>

+**

+** SQLite uses one of these integer values as the second

+** argument to calls it makes to the xLock() and xUnlock() methods

+** of an [sqlite3_io_methods] object.

+*/

+#define SQLITE_LOCK_NONE          0

+#define SQLITE_LOCK_SHARED        1

+#define SQLITE_LOCK_RESERVED      2

+#define SQLITE_LOCK_PENDING       3

+#define SQLITE_LOCK_EXCLUSIVE     4

+

+/*

+** CAPI3REF: Synchronization Type Flags {H10260} <H11120>

+**

+** When SQLite invokes the xSync() method of an

+** [sqlite3_io_methods] object it uses a combination of

+** these integer values as the second argument.

+**

+** When the SQLITE_SYNC_DATAONLY flag is used, it means that the

+** sync operation only needs to flush data to mass storage.  Inode

+** information need not be flushed. The SQLITE_SYNC_NORMAL flag means

+** to use normal fsync() semantics. The SQLITE_SYNC_FULL flag means

+** to use Mac OS-X style fullsync instead of fsync().

+*/

+#define SQLITE_SYNC_NORMAL        0x00002

+#define SQLITE_SYNC_FULL          0x00003

+#define SQLITE_SYNC_DATAONLY      0x00010

+

+/*

+** CAPI3REF: OS Interface Open File Handle {H11110} <S20110>

+**

+** An [sqlite3_file] object represents an open file in the OS

+** interface layer.  Individual OS interface implementations will

+** want to subclass this object by appending additional fields

+** for their own use.  The pMethods entry is a pointer to an

+** [sqlite3_io_methods] object that defines methods for performing

+** I/O operations on the open file.

+*/

+typedef struct sqlite3_file sqlite3_file;

+struct sqlite3_file {

+  const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */

+};

+

+/*

+** CAPI3REF: OS Interface File Virtual Methods Object {H11120} <S20110>

+**

+** Every file opened by the [sqlite3_vfs] xOpen method populates an

+** [sqlite3_file] object (or, more commonly, a subclass of the

+** [sqlite3_file] object) with a pointer to an instance of this object.

+** This object defines the methods used to perform various operations

+** against the open file represented by the [sqlite3_file] object.

+**

+** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or

+** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().

+** The second choice is a Mac OS-X style fullsync.  The [SQLITE_SYNC_DATAONLY]

+** flag may be ORed in to indicate that only the data of the file

+** and not its inode needs to be synced.

+**

+** The integer values to xLock() and xUnlock() are one of

+** <ul>

+** <li> [SQLITE_LOCK_NONE],

+** <li> [SQLITE_LOCK_SHARED],

+** <li> [SQLITE_LOCK_RESERVED],

+** <li> [SQLITE_LOCK_PENDING], or

+** <li> [SQLITE_LOCK_EXCLUSIVE].

+** </ul>

+** xLock() increases the lock. xUnlock() decreases the lock.

+** The xCheckReservedLock() method checks whether any database connection,

+** either in this process or in some other process, is holding a RESERVED,

+** PENDING, or EXCLUSIVE lock on the file.  It returns true

+** if such a lock exists and false otherwise.

+**

+** The xFileControl() method is a generic interface that allows custom

+** VFS implementations to directly control an open file using the

+** [sqlite3_file_control()] interface.  The second "op" argument is an

+** integer opcode.  The third argument is a generic pointer intended to

+** point to a structure that may contain arguments or space in which to

+** write return values.  Potential uses for xFileControl() might be

+** functions to enable blocking locks with timeouts, to change the

+** locking strategy (for example to use dot-file locks), to inquire

+** about the status of a lock, or to break stale locks.  The SQLite

+** core reserves all opcodes less than 100 for its own use.

+** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.

+** Applications that define a custom xFileControl method should use opcodes

+** greater than 100 to avoid conflicts.

+**

+** The xSectorSize() method returns the sector size of the

+** device that underlies the file.  The sector size is the

+** minimum write that can be performed without disturbing

+** other bytes in the file.  The xDeviceCharacteristics()

+** method returns a bit vector describing behaviors of the

+** underlying device:

+**

+** <ul>

+** <li> [SQLITE_IOCAP_ATOMIC]

+** <li> [SQLITE_IOCAP_ATOMIC512]

+** <li> [SQLITE_IOCAP_ATOMIC1K]

+** <li> [SQLITE_IOCAP_ATOMIC2K]

+** <li> [SQLITE_IOCAP_ATOMIC4K]

+** <li> [SQLITE_IOCAP_ATOMIC8K]

+** <li> [SQLITE_IOCAP_ATOMIC16K]

+** <li> [SQLITE_IOCAP_ATOMIC32K]

+** <li> [SQLITE_IOCAP_ATOMIC64K]

+** <li> [SQLITE_IOCAP_SAFE_APPEND]

+** <li> [SQLITE_IOCAP_SEQUENTIAL]

+** </ul>

+**

+** The SQLITE_IOCAP_ATOMIC property means that all writes of

+** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values

+** mean that writes of blocks that are nnn bytes in size and

+** are aligned to an address which is an integer multiple of

+** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means

+** that when data is appended to a file, the data is appended

+** first then the size of the file is extended, never the other

+** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that

+** information is written to disk in the same order as calls

+** to xWrite().

+*/

+typedef struct sqlite3_io_methods sqlite3_io_methods;

+struct sqlite3_io_methods {

+  int iVersion;

+  int (*xClose)(sqlite3_file*);

+  int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);

+  int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);

+  int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);

+  int (*xSync)(sqlite3_file*, int flags);

+  int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);

+  int (*xLock)(sqlite3_file*, int);

+  int (*xUnlock)(sqlite3_file*, int);

+  int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);

+  int (*xFileControl)(sqlite3_file*, int op, void *pArg);

+  int (*xSectorSize)(sqlite3_file*);

+  int (*xDeviceCharacteristics)(sqlite3_file*);

+  /* Additional methods may be added in future releases */

+};

+

+/*

+** CAPI3REF: Standard File Control Opcodes {H11310} <S30800>

+**

+** These integer constants are opcodes for the xFileControl method

+** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]

+** interface.

+**

+** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This

+** opcode causes the xFileControl method to write the current state of

+** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],

+** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])

+** into an integer that the pArg argument points to. This capability

+** is used during testing and only needs to be supported when SQLITE_TEST

+** is defined.

+*/

+#define SQLITE_FCNTL_LOCKSTATE        1

+

+/*

+** CAPI3REF: Mutex Handle {H17110} <S20130>

+**

+** The mutex module within SQLite defines [sqlite3_mutex] to be an

+** abstract type for a mutex object.  The SQLite core never looks

+** at the internal representation of an [sqlite3_mutex].  It only

+** deals with pointers to the [sqlite3_mutex] object.

+**

+** Mutexes are created using [sqlite3_mutex_alloc()].

+*/

+typedef struct sqlite3_mutex sqlite3_mutex;

+

+/*

+** CAPI3REF: OS Interface Object {H11140} <S20100>

+**

+** An instance of the sqlite3_vfs object defines the interface between

+** the SQLite core and the underlying operating system.  The "vfs"

+** in the name of the object stands for "virtual file system".

+**

+** The value of the iVersion field is initially 1 but may be larger in

+** future versions of SQLite.  Additional fields may be appended to this

+** object when the iVersion value is increased.  Note that the structure

+** of the sqlite3_vfs object changes in the transaction between

+** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not

+** modified.

+**

+** The szOsFile field is the size of the subclassed [sqlite3_file]

+** structure used by this VFS.  mxPathname is the maximum length of

+** a pathname in this VFS.

+**

+** Registered sqlite3_vfs objects are kept on a linked list formed by

+** the pNext pointer.  The [sqlite3_vfs_register()]

+** and [sqlite3_vfs_unregister()] interfaces manage this list

+** in a thread-safe way.  The [sqlite3_vfs_find()] interface

+** searches the list.  Neither the application code nor the VFS

+** implementation should use the pNext pointer.

+**

+** The pNext field is the only field in the sqlite3_vfs

+** structure that SQLite will ever modify.  SQLite will only access

+** or modify this field while holding a particular static mutex.

+** The application should never modify anything within the sqlite3_vfs

+** object once the object has been registered.

+**

+** The zName field holds the name of the VFS module.  The name must

+** be unique across all VFS modules.

+**

+** {H11141} SQLite will guarantee that the zFilename parameter to xOpen

+** is either a NULL pointer or string obtained

+** from xFullPathname().  SQLite further guarantees that

+** the string will be valid and unchanged until xClose() is

+** called. {END}  Because of the previous sentense,

+** the [sqlite3_file] can safely store a pointer to the

+** filename if it needs to remember the filename for some reason.

+** If the zFilename parameter is xOpen is a NULL pointer then xOpen

+** must invite its own temporary name for the file.  Whenever the 

+** xFilename parameter is NULL it will also be the case that the

+** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].

+**

+** {H11142} The flags argument to xOpen() includes all bits set in

+** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]

+** or [sqlite3_open16()] is used, then flags includes at least

+** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. {END}

+** If xOpen() opens a file read-only then it sets *pOutFlags to

+** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.

+**

+** {H11143} SQLite will also add one of the following flags to the xOpen()

+** call, depending on the object being opened:

+**

+** <ul>

+** <li>  [SQLITE_OPEN_MAIN_DB]

+** <li>  [SQLITE_OPEN_MAIN_JOURNAL]

+** <li>  [SQLITE_OPEN_TEMP_DB]

+** <li>  [SQLITE_OPEN_TEMP_JOURNAL]

+** <li>  [SQLITE_OPEN_TRANSIENT_DB]

+** <li>  [SQLITE_OPEN_SUBJOURNAL]

+** <li>  [SQLITE_OPEN_MASTER_JOURNAL]

+** </ul> {END}

+**

+** The file I/O implementation can use the object type flags to

+** change the way it deals with files.  For example, an application

+** that does not care about crash recovery or rollback might make

+** the open of a journal file a no-op.  Writes to this journal would

+** also be no-ops, and any attempt to read the journal would return

+** SQLITE_IOERR.  Or the implementation might recognize that a database

+** file will be doing page-aligned sector reads and writes in a random

+** order and set up its I/O subsystem accordingly.

+**

+** SQLite might also add one of the following flags to the xOpen method:

+**

+** <ul>

+** <li> [SQLITE_OPEN_DELETEONCLOSE]

+** <li> [SQLITE_OPEN_EXCLUSIVE]

+** </ul>

+**

+** {H11145} The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be

+** deleted when it is closed.  {H11146} The [SQLITE_OPEN_DELETEONCLOSE]

+** will be set for TEMP  databases, journals and for subjournals.

+**

+** {H11147} The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened

+** for exclusive access.  This flag is set for all files except

+** for the main database file.

+**

+** {H11148} At least szOsFile bytes of memory are allocated by SQLite

+** to hold the  [sqlite3_file] structure passed as the third

+** argument to xOpen. {END}  The xOpen method does not have to

+** allocate the structure; it should just fill it in.

+**

+** {H11149} The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]

+** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to

+** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]

+** to test whether a file is at least readable. {END}  The file can be a

+** directory.

+**

+** {H11150} SQLite will always allocate at least mxPathname+1 bytes for the

+** output buffer xFullPathname. {H11151} The exact size of the output buffer

+** is also passed as a parameter to both  methods. {END}  If the output buffer

+** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is

+** handled as a fatal error by SQLite, vfs implementations should endeavor

+** to prevent this by setting mxPathname to a sufficiently large value.

+**

+** The xRandomness(), xSleep(), and xCurrentTime() interfaces

+** are not strictly a part of the filesystem, but they are

+** included in the VFS structure for completeness.

+** The xRandomness() function attempts to return nBytes bytes

+** of good-quality randomness into zOut.  The return value is

+** the actual number of bytes of randomness obtained.

+** The xSleep() method causes the calling thread to sleep for at

+** least the number of microseconds given.  The xCurrentTime()

+** method returns a Julian Day Number for the current date and time.

+*/

+typedef struct sqlite3_vfs sqlite3_vfs;

+struct sqlite3_vfs {

+  int iVersion;            /* Structure version number */

+  int szOsFile;            /* Size of subclassed sqlite3_file */

+  int mxPathname;          /* Maximum file pathname length */

+  sqlite3_vfs *pNext;      /* Next registered VFS */

+  const char *zName;       /* Name of this virtual file system */

+  void *pAppData;          /* Pointer to application-specific data */

+  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,

+               int flags, int *pOutFlags);

+  int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);

+  int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);

+  int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);

+  void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);

+  void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);

+  void *(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol);

+  void (*xDlClose)(sqlite3_vfs*, void*);

+  int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);

+  int (*xSleep)(sqlite3_vfs*, int microseconds);

+  int (*xCurrentTime)(sqlite3_vfs*, double*);

+  int (*xGetLastError)(sqlite3_vfs*, int, char *);

+  /* New fields may be appended in figure versions.  The iVersion

+  ** value will increment whenever this happens. */

+};

+

+/*

+** CAPI3REF: Flags for the xAccess VFS method {H11190} <H11140>

+**

+** {H11191} These integer constants can be used as the third parameter to

+** the xAccess method of an [sqlite3_vfs] object. {END}  They determine

+** what kind of permissions the xAccess method is looking for.

+** {H11192} With SQLITE_ACCESS_EXISTS, the xAccess method

+** simply checks whether the file exists.

+** {H11193} With SQLITE_ACCESS_READWRITE, the xAccess method

+** checks whether the file is both readable and writable.

+** {H11194} With SQLITE_ACCESS_READ, the xAccess method

+** checks whether the file is readable.

+*/

+#define SQLITE_ACCESS_EXISTS    0

+#define SQLITE_ACCESS_READWRITE 1

+#define SQLITE_ACCESS_READ      2

+

+/*

+** CAPI3REF: Initialize The SQLite Library {H10130} <S20000><S30100>

+**

+** The sqlite3_initialize() routine initializes the

+** SQLite library.  The sqlite3_shutdown() routine

+** deallocates any resources that were allocated by sqlite3_initialize().

+**

+** A call to sqlite3_initialize() is an "effective" call if it is

+** the first time sqlite3_initialize() is invoked during the lifetime of

+** the process, or if it is the first time sqlite3_initialize() is invoked

+** following a call to sqlite3_shutdown().  Only an effective call

+** of sqlite3_initialize() does any initialization.  All other calls

+** are harmless no-ops.

+**

+** Among other things, sqlite3_initialize() shall invoke

+** sqlite3_os_init().  Similarly, sqlite3_shutdown()

+** shall invoke sqlite3_os_end().

+**

+** The sqlite3_initialize() routine returns SQLITE_OK on success.

+** If for some reason, sqlite3_initialize() is unable to initialize

+** the library (perhaps it is unable to allocate a needed resource such

+** as a mutex) it returns an [error code] other than SQLITE_OK.

+**

+** The sqlite3_initialize() routine is called internally by many other

+** SQLite interfaces so that an application usually does not need to

+** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]

+** calls sqlite3_initialize() so the SQLite library will be automatically

+** initialized when [sqlite3_open()] is called if it has not be initialized

+** already.  However, if SQLite is compiled with the SQLITE_OMIT_AUTOINIT

+** compile-time option, then the automatic calls to sqlite3_initialize()

+** are omitted and the application must call sqlite3_initialize() directly

+** prior to using any other SQLite interface.  For maximum portability,

+** it is recommended that applications always invoke sqlite3_initialize()

+** directly prior to using any other SQLite interface.  Future releases

+** of SQLite may require this.  In other words, the behavior exhibited

+** when SQLite is compiled with SQLITE_OMIT_AUTOINIT might become the

+** default behavior in some future release of SQLite.

+**

+** The sqlite3_os_init() routine does operating-system specific

+** initialization of the SQLite library.  The sqlite3_os_end()

+** routine undoes the effect of sqlite3_os_init().  Typical tasks

+** performed by these routines include allocation or deallocation

+** of static resources, initialization of global variables,

+** setting up a default [sqlite3_vfs] module, or setting up

+** a default configuration using [sqlite3_config()].

+**

+** The application should never invoke either sqlite3_os_init()

+** or sqlite3_os_end() directly.  The application should only invoke

+** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()

+** interface is called automatically by sqlite3_initialize() and

+** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate

+** implementations for sqlite3_os_init() and sqlite3_os_end()

+** are built into SQLite when it is compiled for unix, windows, or os/2.

+** When built for other platforms (using the SQLITE_OS_OTHER=1 compile-time

+** option) the application must supply a suitable implementation for

+** sqlite3_os_init() and sqlite3_os_end().  An application-supplied

+** implementation of sqlite3_os_init() or sqlite3_os_end()

+** must return SQLITE_OK on success and some other [error code] upon

+** failure.

+*/

+int sqlite3_initialize(void);

+int sqlite3_shutdown(void);

+int sqlite3_os_init(void);

+int sqlite3_os_end(void);

+

+/*

+** CAPI3REF: Configuring The SQLite Library {H10145} <S20000><S30200>

+** EXPERIMENTAL

+**

+** The sqlite3_config() interface is used to make global configuration

+** changes to SQLite in order to tune SQLite to the specific needs of

+** the application.  The default configuration is recommended for most

+** applications and so this routine is usually not necessary.  It is

+** provided to support rare applications with unusual needs.

+**

+** The sqlite3_config() interface is not threadsafe.  The application

+** must insure that no other SQLite interfaces are invoked by other

+** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()

+** may only be invoked prior to library initialization using

+** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].

+** Note, however, that sqlite3_config() can be called as part of the

+** implementation of an application-defined [sqlite3_os_init()].

+**

+** The first argument to sqlite3_config() is an integer

+** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines

+** what property of SQLite is to be configured.  Subsequent arguments

+** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option]

+** in the first argument.

+**

+** When a configuration option is set, sqlite3_config() returns SQLITE_OK.

+** If the option is unknown or SQLite is unable to set the option

+** then this routine returns a non-zero [error code].

+*/

+int sqlite3_config(int, ...);

+

+/*

+** CAPI3REF: Configure database connections  {H10180} <S20000>

+** EXPERIMENTAL

+**

+** The sqlite3_db_config() interface is used to make configuration

+** changes to a [database connection].  The interface is similar to

+** [sqlite3_config()] except that the changes apply to a single

+** [database connection] (specified in the first argument).  The

+** sqlite3_db_config() interface can only be used immediately after

+** the database connection is created using [sqlite3_open()],

+** [sqlite3_open16()], or [sqlite3_open_v2()].  

+**

+** The second argument to sqlite3_db_config(D,V,...)  is the

+** configuration verb - an integer code that indicates what

+** aspect of the [database connection] is being configured.

+** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE].

+** New verbs are likely to be added in future releases of SQLite.

+** Additional arguments depend on the verb.

+*/

+int sqlite3_db_config(sqlite3*, int op, ...);

+

+/*

+** CAPI3REF: Memory Allocation Routines {H10155} <S20120>

+** EXPERIMENTAL

+**

+** An instance of this object defines the interface between SQLite

+** and low-level memory allocation routines.

+**

+** This object is used in only one place in the SQLite interface.

+** A pointer to an instance of this object is the argument to

+** [sqlite3_config()] when the configuration option is

+** [SQLITE_CONFIG_MALLOC].  By creating an instance of this object

+** and passing it to [sqlite3_config()] during configuration, an

+** application can specify an alternative memory allocation subsystem

+** for SQLite to use for all of its dynamic memory needs.

+**

+** Note that SQLite comes with a built-in memory allocator that is

+** perfectly adequate for the overwhelming majority of applications

+** and that this object is only useful to a tiny minority of applications

+** with specialized memory allocation requirements.  This object is

+** also used during testing of SQLite in order to specify an alternative

+** memory allocator that simulates memory out-of-memory conditions in

+** order to verify that SQLite recovers gracefully from such

+** conditions.

+**

+** The xMalloc, xFree, and xRealloc methods must work like the

+** malloc(), free(), and realloc() functions from the standard library.

+**

+** xSize should return the allocated size of a memory allocation

+** previously obtained from xMalloc or xRealloc.  The allocated size

+** is always at least as big as the requested size but may be larger.

+**

+** The xRoundup method returns what would be the allocated size of

+** a memory allocation given a particular requested size.  Most memory

+** allocators round up memory allocations at least to the next multiple

+** of 8.  Some allocators round up to a larger multiple or to a power of 2.

+**

+** The xInit method initializes the memory allocator.  (For example,

+** it might allocate any require mutexes or initialize internal data

+** structures.  The xShutdown method is invoked (indirectly) by

+** [sqlite3_shutdown()] and should deallocate any resources acquired

+** by xInit.  The pAppData pointer is used as the only parameter to

+** xInit and xShutdown.

+*/

+typedef struct sqlite3_mem_methods sqlite3_mem_methods;

+struct sqlite3_mem_methods {

+  void *(*xMalloc)(int);         /* Memory allocation function */

+  void (*xFree)(void*);          /* Free a prior allocation */

+  void *(*xRealloc)(void*,int);  /* Resize an allocation */

+  int (*xSize)(void*);           /* Return the size of an allocation */

+  int (*xRoundup)(int);          /* Round up request size to allocation size */

+  int (*xInit)(void*);           /* Initialize the memory allocator */

+  void (*xShutdown)(void*);      /* Deinitialize the memory allocator */

+  void *pAppData;                /* Argument to xInit() and xShutdown() */

+};

+

+/*

+** CAPI3REF: Configuration Options {H10160} <S20000>

+** EXPERIMENTAL

+**

+** These constants are the available integer configuration options that

+** can be passed as the first argument to the [sqlite3_config()] interface.

+**

+** New configuration options may be added in future releases of SQLite.

+** Existing configuration options might be discontinued.  Applications

+** should check the return code from [sqlite3_config()] to make sure that

+** the call worked.  The [sqlite3_config()] interface will return a

+** non-zero [error code] if a discontinued or unsupported configuration option

+** is invoked.

+**

+** <dl>

+** <dt>SQLITE_CONFIG_SINGLETHREAD</dt>

+** <dd>There are no arguments to this option.  This option disables

+** all mutexing and puts SQLite into a mode where it can only be used

+** by a single thread.</dd>

+**

+** <dt>SQLITE_CONFIG_MULTITHREAD</dt>

+** <dd>There are no arguments to this option.  This option disables

+** mutexing on [database connection] and [prepared statement] objects.

+** The application is responsible for serializing access to

+** [database connections] and [prepared statements].  But other mutexes

+** are enabled so that SQLite will be safe to use in a multi-threaded

+** environment.</dd>

+**

+** <dt>SQLITE_CONFIG_SERIALIZED</dt>

+** <dd>There are no arguments to this option.  This option enables

+** all mutexes including the recursive

+** mutexes on [database connection] and [prepared statement] objects.

+** In this mode (which is the default when SQLite is compiled with

+** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access

+** to [database connections] and [prepared statements] so that the

+** application is free to use the same [database connection] or the

+** same [prepared statement] in different threads at the same time.

+**

+** <p>This configuration option merely sets the default mutex 

+** behavior to serialize access to [database connections].  Individual

+** [database connections] can override this setting

+** using the [SQLITE_OPEN_NOMUTEX] flag to [sqlite3_open_v2()].</p></dd>

+**

+** <dt>SQLITE_CONFIG_MALLOC</dt>

+** <dd>This option takes a single argument which is a pointer to an

+** instance of the [sqlite3_mem_methods] structure.  The argument specifies

+** alternative low-level memory allocation routines to be used in place of

+** the memory allocation routines built into SQLite.</dd>

+**

+** <dt>SQLITE_CONFIG_GETMALLOC</dt>

+** <dd>This option takes a single argument which is a pointer to an

+** instance of the [sqlite3_mem_methods] structure.  The [sqlite3_mem_methods]

+** structure is filled with the currently defined memory allocation routines.

+** This option can be used to overload the default memory allocation

+** routines with a wrapper that simulations memory allocation failure or

+** tracks memory usage, for example.</dd>

+**

+** <dt>SQLITE_CONFIG_MEMSTATUS</dt>

+** <dd>This option takes single argument of type int, interpreted as a 

+** boolean, which enables or disables the collection of memory allocation 

+** statistics. When disabled, the following SQLite interfaces become 

+** non-operational:

+**   <ul>

+**   <li> [sqlite3_memory_used()]

+**   <li> [sqlite3_memory_highwater()]

+**   <li> [sqlite3_soft_heap_limit()]

+**   <li> [sqlite3_status()]

+**   </ul>

+** </dd>

+**

+** <dt>SQLITE_CONFIG_SCRATCH</dt>

+** <dd>This option specifies a static memory buffer that SQLite can use for

+** scratch memory.  There are three arguments:  A pointer to the memory, the

+** size of each scratch buffer (sz), and the number of buffers (N).  The sz

+** argument must be a multiple of 16. The sz parameter should be a few bytes

+** larger than the actual scratch space required due internal overhead.

+** The first

+** argument should point to an allocation of at least sz*N bytes of memory.

+** SQLite will use no more than one scratch buffer at once per thread, so

+** N should be set to the expected maximum number of threads.  The sz

+** parameter should be 6 times the size of the largest database page size.

+** Scratch buffers are used as part of the btree balance operation.  If

+** The btree balancer needs additional memory beyond what is provided by

+** scratch buffers or if no scratch buffer space is specified, then SQLite

+** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd>

+**

+** <dt>SQLITE_CONFIG_PAGECACHE</dt>

+** <dd>This option specifies a static memory buffer that SQLite can use for

+** the database page cache.  There are three arguments: A pointer to the

+** memory, the size of each page buffer (sz), and the number of pages (N).

+** The sz argument must be a power of two between 512 and 32768.  The first

+** argument should point to an allocation of at least sz*N bytes of memory.

+** SQLite will use the memory provided by the first argument to satisfy its

+** memory needs for the first N pages that it adds to cache.  If additional

+** page cache memory is needed beyond what is provided by this option, then

+** SQLite goes to [sqlite3_malloc()] for the additional storage space.

+** The implementation might use one or more of the N buffers to hold 

+** memory accounting information. </dd>

+**

+** <dt>SQLITE_CONFIG_HEAP</dt>

+** <dd>This option specifies a static memory buffer that SQLite will use

+** for all of its dynamic memory allocation needs beyond those provided

+** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].

+** There are three arguments: A pointer to the memory, the number of

+** bytes in the memory buffer, and the minimum allocation size.  If

+** the first pointer (the memory pointer) is NULL, then SQLite reverts

+** to using its default memory allocator (the system malloc() implementation),

+** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  If the

+** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or

+** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory

+** allocator is engaged to handle all of SQLites memory allocation needs.</dd>

+**

+** <dt>SQLITE_CONFIG_MUTEX</dt>

+** <dd>This option takes a single argument which is a pointer to an

+** instance of the [sqlite3_mutex_methods] structure.  The argument specifies

+** alternative low-level mutex routines to be used in place

+** the mutex routines built into SQLite.</dd>

+**

+** <dt>SQLITE_CONFIG_GETMUTEX</dt>

+** <dd>This option takes a single argument which is a pointer to an

+** instance of the [sqlite3_mutex_methods] structure.  The

+** [sqlite3_mutex_methods]

+** structure is filled with the currently defined mutex routines.

+** This option can be used to overload the default mutex allocation

+** routines with a wrapper used to track mutex usage for performance

+** profiling or testing, for example.</dd>

+**

+** <dt>SQLITE_CONFIG_LOOKASIDE</dt>

+** <dd>This option takes two arguments that determine the default

+** memory allcation lookaside optimization.  The first argument is the

+** size of each lookaside buffer slot and the second is the number of

+** slots allocated to each database connection.</dd>

+**

+** </dl>

+*/

+#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */

+#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */

+#define SQLITE_CONFIG_SERIALIZED    3  /* nil */

+#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */

+#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */

+#define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */

+#define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */

+#define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */

+#define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */

+#define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */

+#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */

+#define SQLITE_CONFIG_CHUNKALLOC   12  /* int threshold */

+#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */

+

+/*

+** CAPI3REF: Configuration Options {H10170} <S20000>

+** EXPERIMENTAL

+**

+** These constants are the available integer configuration options that

+** can be passed as the second argument to the [sqlite3_db_config()] interface.

+**

+** New configuration options may be added in future releases of SQLite.

+** Existing configuration options might be discontinued.  Applications

+** should check the return code from [sqlite3_db_config()] to make sure that

+** the call worked.  The [sqlite3_db_config()] interface will return a

+** non-zero [error code] if a discontinued or unsupported configuration option

+** is invoked.

+**

+** <dl>

+** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>

+** <dd>This option takes three additional arguments that determine the 

+** [lookaside memory allocator] configuration for the [database connection].

+** The first argument (the third parameter to [sqlite3_db_config()] is a

+** pointer to a memory buffer to use for lookaside memory.  The first

+** argument may be NULL in which case SQLite will allocate the lookaside

+** buffer itself using [sqlite3_malloc()].  The second argument is the

+** size of each lookaside buffer slot and the third argument is the number of

+** slots.  The size of the buffer in the first argument must be greater than

+** or equal to the product of the second and third arguments.</dd>

+**

+** </dl>

+*/

+#define SQLITE_DBCONFIG_LOOKASIDE    1001  /* void* int int */

+

+

+/*

+** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} <S10700>

+**

+** The sqlite3_extended_result_codes() routine enables or disables the

+** [extended result codes] feature of SQLite. The extended result

+** codes are disabled by default for historical compatibility considerations.

+**

+** INVARIANTS:

+**

+** {H12201} Each new [database connection] shall have the

+**          [extended result codes] feature disabled by default.

+**

+** {H12202} The [sqlite3_extended_result_codes(D,F)] interface shall enable

+**          [extended result codes] for the  [database connection] D

+**          if the F parameter is true, or disable them if F is false.

+*/

+int sqlite3_extended_result_codes(sqlite3*, int onoff);

+

+/*

+** CAPI3REF: Last Insert Rowid {H12220} <S10700>

+**

+** Each entry in an SQLite table has a unique 64-bit signed

+** integer key called the "rowid". The rowid is always available

+** as an undeclared column named ROWID, OID, or _ROWID_ as long as those

+** names are not also used by explicitly declared columns. If

+** the table has a column of type INTEGER PRIMARY KEY then that column

+** is another alias for the rowid.

+**

+** This routine returns the rowid of the most recent

+** successful INSERT into the database from the [database connection]

+** in the first argument.  If no successful INSERTs

+** have ever occurred on that database connection, zero is returned.

+**

+** If an INSERT occurs within a trigger, then the rowid of the inserted

+** row is returned by this routine as long as the trigger is running.

+** But once the trigger terminates, the value returned by this routine

+** reverts to the last value inserted before the trigger fired.

+**

+** An INSERT that fails due to a constraint violation is not a

+** successful INSERT and does not change the value returned by this

+** routine.  Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,

+** and INSERT OR ABORT make no changes to the return value of this

+** routine when their insertion fails.  When INSERT OR REPLACE

+** encounters a constraint violation, it does not fail.  The

+** INSERT continues to completion after deleting rows that caused

+** the constraint problem so INSERT OR REPLACE will always change

+** the return value of this interface.

+**

+** For the purposes of this routine, an INSERT is considered to

+** be successful even if it is subsequently rolled back.

+**

+** INVARIANTS:

+**

+** {H12221} The [sqlite3_last_insert_rowid()] function returns the rowid

+**          of the most recent successful INSERT performed on the same

+**          [database connection] and within the same or higher level

+**          trigger context, or zero if there have been no qualifying inserts.

+**

+** {H12223} The [sqlite3_last_insert_rowid()] function returns the

+**          same value when called from the same trigger context

+**          immediately before and after a ROLLBACK.

+**

+** ASSUMPTIONS:

+**

+** {A12232} If a separate thread performs a new INSERT on the same

+**          database connection while the [sqlite3_last_insert_rowid()]

+**          function is running and thus changes the last insert rowid,

+**          then the value returned by [sqlite3_last_insert_rowid()] is

+**          unpredictable and might not equal either the old or the new

+**          last insert rowid.

+*/

+sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

+

+/*

+** CAPI3REF: Count The Number Of Rows Modified {H12240} <S10600>

+**

+** This function returns the number of database rows that were changed

+** or inserted or deleted by the most recently completed SQL statement

+** on the [database connection] specified by the first parameter.

+** Only changes that are directly specified by the INSERT, UPDATE,

+** or DELETE statement are counted.  Auxiliary changes caused by

+** triggers are not counted. Use the [sqlite3_total_changes()] function

+** to find the total number of changes including changes caused by triggers.

+**

+** A "row change" is a change to a single row of a single table

+** caused by an INSERT, DELETE, or UPDATE statement.  Rows that

+** are changed as side effects of REPLACE constraint resolution,

+** rollback, ABORT processing, DROP TABLE, or by any other

+** mechanisms do not count as direct row changes.

+**

+** A "trigger context" is a scope of execution that begins and

+** ends with the script of a trigger.  Most SQL statements are

+** evaluated outside of any trigger.  This is the "top level"

+** trigger context.  If a trigger fires from the top level, a

+** new trigger context is entered for the duration of that one

+** trigger.  Subtriggers create subcontexts for their duration.

+**

+** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does

+** not create a new trigger context.

+**

+** This function returns the number of direct row changes in the

+** most recent INSERT, UPDATE, or DELETE statement within the same

+** trigger context.

+**

+** Thus, when called from the top level, this function returns the

+** number of changes in the most recent INSERT, UPDATE, or DELETE

+** that also occurred at the top level.  Within the body of a trigger,

+** the sqlite3_changes() interface can be called to find the number of

+** changes in the most recently completed INSERT, UPDATE, or DELETE

+** statement within the body of the same trigger.

+** However, the number returned does not include changes

+** caused by subtriggers since those have their own context.

+**

+** SQLite implements the command "DELETE FROM table" without a WHERE clause

+** by dropping and recreating the table.  (This is much faster than going

+** through and deleting individual elements from the table.)  Because of this

+** optimization, the deletions in "DELETE FROM table" are not row changes and

+** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()]

+** functions, regardless of the number of elements that were originally

+** in the table.  To get an accurate count of the number of rows deleted, use

+** "DELETE FROM table WHERE 1" instead.

+**

+** INVARIANTS:

+**

+** {H12241} The [sqlite3_changes()] function shall return the number of

+**          row changes caused by the most recent INSERT, UPDATE,

+**          or DELETE statement on the same database connection and

+**          within the same or higher trigger context, or zero if there have

+**          not been any qualifying row changes.

+**

+** {H12243} Statements of the form "DELETE FROM tablename" with no

+**          WHERE clause shall cause subsequent calls to

+**          [sqlite3_changes()] to return zero, regardless of the

+**          number of rows originally in the table.

+**

+** ASSUMPTIONS:

+**

+** {A12252} If a separate thread makes changes on the same database connection

+**          while [sqlite3_changes()] is running then the value returned

+**          is unpredictable and not meaningful.

+*/

+int sqlite3_changes(sqlite3*);

+

+/*

+** CAPI3REF: Total Number Of Rows Modified {H12260} <S10600>

+**

+** This function returns the number of row changes caused by INSERT,

+** UPDATE or DELETE statements since the [database connection] was opened.

+** The count includes all changes from all trigger contexts.  However,

+** the count does not include changes used to implement REPLACE constraints,

+** do rollbacks or ABORT processing, or DROP table processing.

+** The changes are counted as soon as the statement that makes them is

+** completed (when the statement handle is passed to [sqlite3_reset()] or

+** [sqlite3_finalize()]).

+**

+** SQLite implements the command "DELETE FROM table" without a WHERE clause

+** by dropping and recreating the table.  (This is much faster than going

+** through and deleting individual elements from the table.)  Because of this

+** optimization, the deletions in "DELETE FROM table" are not row changes and

+** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()]

+** functions, regardless of the number of elements that were originally

+** in the table.  To get an accurate count of the number of rows deleted, use

+** "DELETE FROM table WHERE 1" instead.

+**

+** See also the [sqlite3_changes()] interface.

+**

+** INVARIANTS:

+**

+** {H12261} The [sqlite3_total_changes()] returns the total number

+**          of row changes caused by INSERT, UPDATE, and/or DELETE

+**          statements on the same [database connection], in any

+**          trigger context, since the database connection was created.

+**

+** {H12263} Statements of the form "DELETE FROM tablename" with no

+**          WHERE clause shall not change the value returned

+**          by [sqlite3_total_changes()].

+**

+** ASSUMPTIONS:

+**

+** {A12264} If a separate thread makes changes on the same database connection

+**          while [sqlite3_total_changes()] is running then the value

+**          returned is unpredictable and not meaningful.

+*/

+int sqlite3_total_changes(sqlite3*);

+

+/*

+** CAPI3REF: Interrupt A Long-Running Query {H12270} <S30500>

+**

+** This function causes any pending database operation to abort and

+** return at its earliest opportunity. This routine is typically

+** called in response to a user action such as pressing "Cancel"

+** or Ctrl-C where the user wants a long query operation to halt

+** immediately.

+**

+** It is safe to call this routine from a thread different from the

+** thread that is currently running the database operation.  But it

+** is not safe to call this routine with a [database connection] that

+** is closed or might close before sqlite3_interrupt() returns.

+**

+** If an SQL operation is very nearly finished at the time when

+** sqlite3_interrupt() is called, then it might not have an opportunity

+** to be interrupted and might continue to completion.

+**

+** An SQL operation that is interrupted will return [SQLITE_INTERRUPT].

+** If the interrupted SQL operation is an INSERT, UPDATE, or DELETE

+** that is inside an explicit transaction, then the entire transaction

+** will be rolled back automatically.

+**

+** A call to sqlite3_interrupt() has no effect on SQL statements

+** that are started after sqlite3_interrupt() returns.

+**

+** INVARIANTS:

+**

+** {H12271} The [sqlite3_interrupt()] interface will force all running

+**          SQL statements associated with the same database connection

+**          to halt after processing at most one additional row of data.

+**

+** {H12272} Any SQL statement that is interrupted by [sqlite3_interrupt()]

+**          will return [SQLITE_INTERRUPT].

+**

+** ASSUMPTIONS:

+**

+** {A12279} If the database connection closes while [sqlite3_interrupt()]

+**          is running then bad things will likely happen.

+*/

+void sqlite3_interrupt(sqlite3*);

+

+/*

+** CAPI3REF: Determine If An SQL Statement Is Complete {H10510} <S70200>

+**

+** These routines are useful for command-line input to determine if the

+** currently entered text seems to form complete a SQL statement or

+** if additional input is needed before sending the text into

+** SQLite for parsing.  These routines return true if the input string

+** appears to be a complete SQL statement.  A statement is judged to be

+** complete if it ends with a semicolon token and is not a fragment of a

+** CREATE TRIGGER statement.  Semicolons that are embedded within

+** string literals or quoted identifier names or comments are not

+** independent tokens (they are part of the token in which they are

+** embedded) and thus do not count as a statement terminator.

+**

+** These routines do not parse the SQL statements thus

+** will not detect syntactically incorrect SQL.

+**

+** INVARIANTS:

+**

+** {H10511} A successful evaluation of [sqlite3_complete()] or

+**          [sqlite3_complete16()] functions shall

+**          return a numeric 1 if and only if the last non-whitespace

+**          token in their input is a semicolon that is not in between

+**          the BEGIN and END of a CREATE TRIGGER statement.

+**

+** {H10512} If a memory allocation error occurs during an invocation

+**          of [sqlite3_complete()] or [sqlite3_complete16()] then the

+**          routine shall return [SQLITE_NOMEM].

+**

+** ASSUMPTIONS:

+**

+** {A10512} The input to [sqlite3_complete()] must be a zero-terminated

+**          UTF-8 string.

+**

+** {A10513} The input to [sqlite3_complete16()] must be a zero-terminated

+**          UTF-16 string in native byte order.

+*/

+int sqlite3_complete(const char *sql);

+int sqlite3_complete16(const void *sql);

+

+/*

+** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400>

+**

+** This routine sets a callback function that might be invoked whenever

+** an attempt is made to open a database table that another thread

+** or process has locked.

+**

+** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]

+** is returned immediately upon encountering the lock. If the busy callback

+** is not NULL, then the callback will be invoked with two arguments.

+**

+** The first argument to the handler is a copy of the void* pointer which

+** is the third argument to sqlite3_busy_handler().  The second argument to

+** the handler callback is the number of times that the busy handler has

+** been invoked for this locking event.  If the

+** busy callback returns 0, then no additional attempts are made to

+** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.

+** If the callback returns non-zero, then another attempt

+** is made to open the database for reading and the cycle repeats.

+**

+** The presence of a busy handler does not guarantee that it will be invoked

+** when there is lock contention. If SQLite determines that invoking the busy

+** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]

+** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.

+** Consider a scenario where one process is holding a read lock that

+** it is trying to promote to a reserved lock and

+** a second process is holding a reserved lock that it is trying

+** to promote to an exclusive lock.  The first process cannot proceed

+** because it is blocked by the second and the second process cannot

+** proceed because it is blocked by the first.  If both processes

+** invoke the busy handlers, neither will make any progress.  Therefore,

+** SQLite returns [SQLITE_BUSY] for the first process, hoping that this

+** will induce the first process to release its read lock and allow

+** the second process to proceed.

+**

+** The default busy callback is NULL.

+**

+** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]

+** when SQLite is in the middle of a large transaction where all the

+** changes will not fit into the in-memory cache.  SQLite will

+** already hold a RESERVED lock on the database file, but it needs

+** to promote this lock to EXCLUSIVE so that it can spill cache

+** pages into the database file without harm to concurrent

+** readers.  If it is unable to promote the lock, then the in-memory

+** cache will be left in an inconsistent state and so the error

+** code is promoted from the relatively benign [SQLITE_BUSY] to

+** the more severe [SQLITE_IOERR_BLOCKED].  This error code promotion

+** forces an automatic rollback of the changes.  See the

+** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">

+** CorruptionFollowingBusyError</a> wiki page for a discussion of why

+** this is important.

+**

+** There can only be a single busy handler defined for each

+** [database connection].  Setting a new busy handler clears any

+** previously set handler.  Note that calling [sqlite3_busy_timeout()]

+** will also set or clear the busy handler.

+**

+** INVARIANTS:

+**

+** {H12311} The [sqlite3_busy_handler(D,C,A)] function shall replace

+**          busy callback in the [database connection] D with a new

+**          a new busy handler C and application data pointer A.

+**

+** {H12312} Newly created [database connections] shall have a busy

+**          handler of NULL.

+**

+** {H12314} When two or more [database connections] share a

+**          [sqlite3_enable_shared_cache | common cache],

+**          the busy handler for the database connection currently using

+**          the cache shall be invoked when the cache encounters a lock.

+**

+** {H12316} If a busy handler callback returns zero, then the SQLite interface

+**          that provoked the locking event shall return [SQLITE_BUSY].

+**

+** {H12318} SQLite shall invokes the busy handler with two arguments which

+**          are a copy of the pointer supplied by the 3rd parameter to

+**          [sqlite3_busy_handler()] and a count of the number of prior

+**          invocations of the busy handler for the same locking event.

+**

+** ASSUMPTIONS:

+**

+** {A12319} A busy handler must not close the database connection

+**          or [prepared statement] that invoked the busy handler.

+*/

+int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);

+

+/*

+** CAPI3REF: Set A Busy Timeout {H12340} <S40410>

+**

+** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps

+** for a specified amount of time when a table is locked.  The handler

+** will sleep multiple times until at least "ms" milliseconds of sleeping

+** have accumulated. {H12343} After "ms" milliseconds of sleeping,

+** the handler returns 0 which causes [sqlite3_step()] to return

+** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].

+**

+** Calling this routine with an argument less than or equal to zero

+** turns off all busy handlers.

+**

+** There can only be a single busy handler for a particular

+** [database connection] any any given moment.  If another busy handler

+** was defined  (using [sqlite3_busy_handler()]) prior to calling

+** this routine, that other busy handler is cleared.

+**

+** INVARIANTS:

+**

+** {H12341} The [sqlite3_busy_timeout()] function shall override any prior

+**          [sqlite3_busy_timeout()] or [sqlite3_busy_handler()] setting

+**          on the same [database connection].

+**

+** {H12343} If the 2nd parameter to [sqlite3_busy_timeout()] is less than

+**          or equal to zero, then the busy handler shall be cleared so that

+**          all subsequent locking events immediately return [SQLITE_BUSY].

+**

+** {H12344} If the 2nd parameter to [sqlite3_busy_timeout()] is a positive

+**          number N, then a busy handler shall be set that repeatedly calls

+**          the xSleep() method in the [sqlite3_vfs | VFS interface] until

+**          either the lock clears or until the cumulative sleep time

+**          reported back by xSleep() exceeds N milliseconds.

+*/

+int sqlite3_busy_timeout(sqlite3*, int ms);

+

+/*

+** CAPI3REF: Convenience Routines For Running Queries {H12370} <S10000>

+**

+** Definition: A <b>result table</b> is memory data structure created by the

+** [sqlite3_get_table()] interface.  A result table records the

+** complete query results from one or more queries.

+**

+** The table conceptually has a number of rows and columns.  But

+** these numbers are not part of the result table itself.  These

+** numbers are obtained separately.  Let N be the number of rows

+** and M be the number of columns.

+**

+** A result table is an array of pointers to zero-terminated UTF-8 strings.

+** There are (N+1)*M elements in the array.  The first M pointers point

+** to zero-terminated strings that  contain the names of the columns.

+** The remaining entries all point to query results.  NULL values result

+** in NULL pointers.  All other values are in their UTF-8 zero-terminated

+** string representation as returned by [sqlite3_column_text()].

+**

+** A result table might consist of one or more memory allocations.

+** It is not safe to pass a result table directly to [sqlite3_free()].

+** A result table should be deallocated using [sqlite3_free_table()].

+**

+** As an example of the result table format, suppose a query result

+** is as follows:

+**

+** <blockquote><pre>

+**        Name        | Age

+**        -----------------------

+**        Alice       | 43

+**        Bob         | 28

+**        Cindy       | 21

+** </pre></blockquote>

+**

+** There are two column (M==2) and three rows (N==3).  Thus the

+** result table has 8 entries.  Suppose the result table is stored

+** in an array names azResult.  Then azResult holds this content:

+**

+** <blockquote><pre>

+**        azResult&#91;0] = "Name";

+**        azResult&#91;1] = "Age";

+**        azResult&#91;2] = "Alice";

+**        azResult&#91;3] = "43";

+**        azResult&#91;4] = "Bob";

+**        azResult&#91;5] = "28";

+**        azResult&#91;6] = "Cindy";

+**        azResult&#91;7] = "21";

+** </pre></blockquote>

+**

+** The sqlite3_get_table() function evaluates one or more

+** semicolon-separated SQL statements in the zero-terminated UTF-8

+** string of its 2nd parameter.  It returns a result table to the

+** pointer given in its 3rd parameter.

+**

+** After the calling function has finished using the result, it should

+** pass the pointer to the result table to sqlite3_free_table() in order to

+** release the memory that was malloced.  Because of the way the

+** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling

+** function must not try to call [sqlite3_free()] directly.  Only

+** [sqlite3_free_table()] is able to release the memory properly and safely.

+**

+** The sqlite3_get_table() interface is implemented as a wrapper around

+** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access

+** to any internal data structures of SQLite.  It uses only the public

+** interface defined here.  As a consequence, errors that occur in the

+** wrapper layer outside of the internal [sqlite3_exec()] call are not

+** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()].

+**

+** INVARIANTS:

+**

+** {H12371} If a [sqlite3_get_table()] fails a memory allocation, then

+**          it shall free the result table under construction, abort the

+**          query in process, skip any subsequent queries, set the

+**          *pazResult output pointer to NULL and return [SQLITE_NOMEM].

+**

+** {H12373} If the pnColumn parameter to [sqlite3_get_table()] is not NULL

+**          then a successful invocation of [sqlite3_get_table()] shall

+**          write the number of columns in the

+**          result set of the query into *pnColumn.

+**

+** {H12374} If the pnRow parameter to [sqlite3_get_table()] is not NULL

+**          then a successful invocation of [sqlite3_get_table()] shall

+**          writes the number of rows in the

+**          result set of the query into *pnRow.

+**

+** {H12376} A successful invocation of [sqlite3_get_table()] that computes

+**          N rows of result with C columns per row shall make *pazResult

+**          point to an array of pointers to (N+1)*C strings where the first

+**          C strings are column names as obtained from

+**          [sqlite3_column_name()] and the rest are column result values

+**          obtained from [sqlite3_column_text()].

+**

+** {H12379} The values in the pazResult array returned by [sqlite3_get_table()]

+**          shall remain valid until cleared by [sqlite3_free_table()].

+**

+** {H12382} When an error occurs during evaluation of [sqlite3_get_table()]

+**          the function shall set *pazResult to NULL, write an error message

+**          into memory obtained from [sqlite3_malloc()], make

+**          **pzErrmsg point to that error message, and return a

+**          appropriate [error code].

+*/

+int sqlite3_get_table(

+  sqlite3 *db,          /* An open database */

+  const char *zSql,     /* SQL to be evaluated */

+  char ***pazResult,    /* Results of the query */

+  int *pnRow,           /* Number of result rows written here */

+  int *pnColumn,        /* Number of result columns written here */

+  char **pzErrmsg       /* Error msg written here */

+);

+void sqlite3_free_table(char **result);

+

+/*

+** CAPI3REF: Formatted String Printing Functions {H17400} <S70000><S20000>

+**

+** These routines are workalikes of the "printf()" family of functions

+** from the standard C library.

+**

+** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their

+** results into memory obtained from [sqlite3_malloc()].

+** The strings returned by these two routines should be

+** released by [sqlite3_free()].  Both routines return a

+** NULL pointer if [sqlite3_malloc()] is unable to allocate enough

+** memory to hold the resulting string.

+**

+** In sqlite3_snprintf() routine is similar to "snprintf()" from

+** the standard C library.  The result is written into the

+** buffer supplied as the second parameter whose size is given by

+** the first parameter. Note that the order of the

+** first two parameters is reversed from snprintf().  This is an

+** historical accident that cannot be fixed without breaking

+** backwards compatibility.  Note also that sqlite3_snprintf()

+** returns a pointer to its buffer instead of the number of

+** characters actually written into the buffer.  We admit that

+** the number of characters written would be a more useful return

+** value but we cannot change the implementation of sqlite3_snprintf()

+** now without breaking compatibility.

+**

+** As long as the buffer size is greater than zero, sqlite3_snprintf()

+** guarantees that the buffer is always zero-terminated.  The first

+** parameter "n" is the total size of the buffer, including space for

+** the zero terminator.  So the longest string that can be completely

+** written will be n-1 characters.

+**

+** These routines all implement some additional formatting

+** options that are useful for constructing SQL statements.

+** All of the usual printf() formatting options apply.  In addition, there

+** is are "%q", "%Q", and "%z" options.

+**

+** The %q option works like %s in that it substitutes a null-terminated

+** string from the argument list.  But %q also doubles every '\'' character.

+** %q is designed for use inside a string literal.  By doubling each '\''

+** character it escapes that character and allows it to be inserted into

+** the string.

+**

+** For example, assume the string variable zText contains text as follows:

+**

+** <blockquote><pre>

+**  char *zText = "It's a happy day!";

+** </pre></blockquote>

+**

+** One can use this text in an SQL statement as follows:

+**

+** <blockquote><pre>

+**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);

+**  sqlite3_exec(db, zSQL, 0, 0, 0);

+**  sqlite3_free(zSQL);

+** </pre></blockquote>

+**

+** Because the %q format string is used, the '\'' character in zText

+** is escaped and the SQL generated is as follows:

+**

+** <blockquote><pre>

+**  INSERT INTO table1 VALUES('It''s a happy day!')

+** </pre></blockquote>

+**

+** This is correct.  Had we used %s instead of %q, the generated SQL

+** would have looked like this:

+**

+** <blockquote><pre>

+**  INSERT INTO table1 VALUES('It's a happy day!');

+** </pre></blockquote>

+**

+** This second example is an SQL syntax error.  As a general rule you should

+** always use %q instead of %s when inserting text into a string literal.

+**

+** The %Q option works like %q except it also adds single quotes around

+** the outside of the total string.  Additionally, if the parameter in the

+** argument list is a NULL pointer, %Q substitutes the text "NULL" (without

+** single quotes) in place of the %Q option.  So, for example, one could say:

+**

+** <blockquote><pre>

+**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);

+**  sqlite3_exec(db, zSQL, 0, 0, 0);

+**  sqlite3_free(zSQL);

+** </pre></blockquote>

+**

+** The code above will render a correct SQL statement in the zSQL

+** variable even if the zText variable is a NULL pointer.

+**

+** The "%z" formatting option works exactly like "%s" with the

+** addition that after the string has been read and copied into

+** the result, [sqlite3_free()] is called on the input string. {END}

+**

+** INVARIANTS:

+**

+** {H17403}  The [sqlite3_mprintf()] and [sqlite3_vmprintf()] interfaces

+**           return either pointers to zero-terminated UTF-8 strings held in

+**           memory obtained from [sqlite3_malloc()] or NULL pointers if

+**           a call to [sqlite3_malloc()] fails.

+**

+** {H17406}  The [sqlite3_snprintf()] interface writes a zero-terminated

+**           UTF-8 string into the buffer pointed to by the second parameter

+**           provided that the first parameter is greater than zero.

+**

+** {H17407}  The [sqlite3_snprintf()] interface does not write slots of

+**           its output buffer (the second parameter) outside the range

+**           of 0 through N-1 (where N is the first parameter)

+**           regardless of the length of the string

+**           requested by the format specification.

+*/

+char *sqlite3_mprintf(const char*,...);

+char *sqlite3_vmprintf(const char*, va_list);

+char *sqlite3_snprintf(int,char*,const char*, ...);

+

+/*

+** CAPI3REF: Memory Allocation Subsystem {H17300} <S20000>

+**

+** The SQLite core  uses these three routines for all of its own

+** internal memory allocation needs. "Core" in the previous sentence

+** does not include operating-system specific VFS implementation.  The

+** Windows VFS uses native malloc() and free() for some operations.

+**

+** The sqlite3_malloc() routine returns a pointer to a block

+** of memory at least N bytes in length, where N is the parameter.

+** If sqlite3_malloc() is unable to obtain sufficient free

+** memory, it returns a NULL pointer.  If the parameter N to

+** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns

+** a NULL pointer.

+**

+** Calling sqlite3_free() with a pointer previously returned

+** by sqlite3_malloc() or sqlite3_realloc() releases that memory so

+** that it might be reused.  The sqlite3_free() routine is

+** a no-op if is called with a NULL pointer.  Passing a NULL pointer

+** to sqlite3_free() is harmless.  After being freed, memory

+** should neither be read nor written.  Even reading previously freed

+** memory might result in a segmentation fault or other severe error.

+** Memory corruption, a segmentation fault, or other severe error

+** might result if sqlite3_free() is called with a non-NULL pointer that

+** was not obtained from sqlite3_malloc() or sqlite3_free().

+**

+** The sqlite3_realloc() interface attempts to resize a

+** prior memory allocation to be at least N bytes, where N is the

+** second parameter.  The memory allocation to be resized is the first

+** parameter.  If the first parameter to sqlite3_realloc()

+** is a NULL pointer then its behavior is identical to calling

+** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().

+** If the second parameter to sqlite3_realloc() is zero or

+** negative then the behavior is exactly the same as calling

+** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().

+** sqlite3_realloc() returns a pointer to a memory allocation

+** of at least N bytes in size or NULL if sufficient memory is unavailable.

+** If M is the size of the prior allocation, then min(N,M) bytes

+** of the prior allocation are copied into the beginning of buffer returned

+** by sqlite3_realloc() and the prior allocation is freed.

+** If sqlite3_realloc() returns NULL, then the prior allocation

+** is not freed.

+**

+** The memory returned by sqlite3_malloc() and sqlite3_realloc()

+** is always aligned to at least an 8 byte boundary. {END}

+**

+** The default implementation of the memory allocation subsystem uses

+** the malloc(), realloc() and free() provided by the standard C library.

+** {H17382} However, if SQLite is compiled with the

+** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i>

+** is an integer), then SQLite create a static array of at least

+** <i>NNN</i> bytes in size and uses that array for all of its dynamic

+** memory allocation needs. {END}  Additional memory allocator options

+** may be added in future releases.

+**

+** In SQLite version 3.5.0 and 3.5.1, it was possible to define

+** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in

+** implementation of these routines to be omitted.  That capability

+** is no longer provided.  Only built-in memory allocators can be used.

+**

+** The Windows OS interface layer calls

+** the system malloc() and free() directly when converting

+** filenames between the UTF-8 encoding used by SQLite

+** and whatever filename encoding is used by the particular Windows

+** installation.  Memory allocation errors are detected, but

+** they are reported back as [SQLITE_CANTOPEN] or

+** [SQLITE_IOERR] rather than [SQLITE_NOMEM].

+**

+** INVARIANTS:

+**

+** {H17303}  The [sqlite3_malloc(N)] interface returns either a pointer to

+**           a newly checked-out block of at least N bytes of memory

+**           that is 8-byte aligned, or it returns NULL if it is unable

+**           to fulfill the request.

+**

+** {H17304}  The [sqlite3_malloc(N)] interface returns a NULL pointer if

+**           N is less than or equal to zero.

+**

+** {H17305}  The [sqlite3_free(P)] interface releases memory previously

+**           returned from [sqlite3_malloc()] or [sqlite3_realloc()],

+**           making it available for reuse.

+**

+** {H17306}  A call to [sqlite3_free(NULL)] is a harmless no-op.

+**

+** {H17310}  A call to [sqlite3_realloc(0,N)] is equivalent to a call

+**           to [sqlite3_malloc(N)].

+**

+** {H17312}  A call to [sqlite3_realloc(P,0)] is equivalent to a call

+**           to [sqlite3_free(P)].

+**

+** {H17315}  The SQLite core uses [sqlite3_malloc()], [sqlite3_realloc()],

+**           and [sqlite3_free()] for all of its memory allocation and

+**           deallocation needs.

+**

+** {H17318}  The [sqlite3_realloc(P,N)] interface returns either a pointer

+**           to a block of checked-out memory of at least N bytes in size

+**           that is 8-byte aligned, or a NULL pointer.

+**

+** {H17321}  When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first

+**           copies the first K bytes of content from P into the newly

+**           allocated block, where K is the lesser of N and the size of

+**           the buffer P.

+**

+** {H17322}  When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first

+**           releases the buffer P.

+**

+** {H17323}  When [sqlite3_realloc(P,N)] returns NULL, the buffer P is

+**           not modified or released.

+**

+** ASSUMPTIONS:

+**

+** {A17350}  The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]

+**           must be either NULL or else pointers obtained from a prior

+**           invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have

+**           not yet been released.

+**

+** {A17351}  The application must not read or write any part of

+**           a block of memory after it has been released using

+**           [sqlite3_free()] or [sqlite3_realloc()].

+*/

+void *sqlite3_malloc(int);

+void *sqlite3_realloc(void*, int);

+void sqlite3_free(void*);

+

+/*

+** CAPI3REF: Memory Allocator Statistics {H17370} <S30210>

+**

+** SQLite provides these two interfaces for reporting on the status

+** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]

+** routines, which form the built-in memory allocation subsystem.

+**

+** INVARIANTS:

+**

+** {H17371} The [sqlite3_memory_used()] routine returns the number of bytes

+**          of memory currently outstanding (malloced but not freed).

+**

+** {H17373} The [sqlite3_memory_highwater()] routine returns the maximum

+**          value of [sqlite3_memory_used()] since the high-water mark

+**          was last reset.

+**

+** {H17374} The values returned by [sqlite3_memory_used()] and

+**          [sqlite3_memory_highwater()] include any overhead

+**          added by SQLite in its implementation of [sqlite3_malloc()],

+**          but not overhead added by the any underlying system library

+**          routines that [sqlite3_malloc()] may call.

+**

+** {H17375} The memory high-water mark is reset to the current value of

+**          [sqlite3_memory_used()] if and only if the parameter to

+**          [sqlite3_memory_highwater()] is true.  The value returned

+**          by [sqlite3_memory_highwater(1)] is the high-water mark

+**          prior to the reset.

+*/

+sqlite3_int64 sqlite3_memory_used(void);

+sqlite3_int64 sqlite3_memory_highwater(int resetFlag);

+

+/*

+** CAPI3REF: Pseudo-Random Number Generator {H17390} <S20000>

+**

+** SQLite contains a high-quality pseudo-random number generator (PRNG) used to

+** select random ROWIDs when inserting new records into a table that

+** already uses the largest possible ROWID.  The PRNG is also used for

+** the build-in random() and randomblob() SQL functions.  This interface allows

+** applications to access the same PRNG for other purposes.

+**

+** A call to this routine stores N bytes of randomness into buffer P.

+**

+** The first time this routine is invoked (either internally or by

+** the application) the PRNG is seeded using randomness obtained

+** from the xRandomness method of the default [sqlite3_vfs] object.

+** On all subsequent invocations, the pseudo-randomness is generated

+** internally and without recourse to the [sqlite3_vfs] xRandomness

+** method.

+**

+** INVARIANTS:

+**

+** {H17392} The [sqlite3_randomness(N,P)] interface writes N bytes of

+**          high-quality pseudo-randomness into buffer P.

+*/

+void sqlite3_randomness(int N, void *P);

+

+/*

+** CAPI3REF: Compile-Time Authorization Callbacks {H12500} <S70100>

+**

+** This routine registers a authorizer callback with a particular

+** [database connection], supplied in the first argument.

+** The authorizer callback is invoked as SQL statements are being compiled

+** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],

+** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  At various

+** points during the compilation process, as logic is being created

+** to perform various actions, the authorizer callback is invoked to

+** see if those actions are allowed.  The authorizer callback should

+** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the

+** specific action but allow the SQL statement to continue to be

+** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be

+** rejected with an error.  If the authorizer callback returns

+** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]

+** then the [sqlite3_prepare_v2()] or equivalent call that triggered

+** the authorizer will fail with an error message.

+**

+** When the callback returns [SQLITE_OK], that means the operation

+** requested is ok.  When the callback returns [SQLITE_DENY], the

+** [sqlite3_prepare_v2()] or equivalent call that triggered the

+** authorizer will fail with an error message explaining that

+** access is denied.  If the authorizer code is [SQLITE_READ]

+** and the callback returns [SQLITE_IGNORE] then the

+** [prepared statement] statement is constructed to substitute

+** a NULL value in place of the table column that would have

+** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]

+** return can be used to deny an untrusted user access to individual

+** columns of a table.

+**

+** The first parameter to the authorizer callback is a copy of the third

+** parameter to the sqlite3_set_authorizer() interface. The second parameter

+** to the callback is an integer [SQLITE_COPY | action code] that specifies

+** the particular action to be authorized. The third through sixth parameters

+** to the callback are zero-terminated strings that contain additional

+** details about the action to be authorized.

+**

+** An authorizer is used when [sqlite3_prepare | preparing]

+** SQL statements from an untrusted source, to ensure that the SQL statements

+** do not try to access data they are not allowed to see, or that they do not

+** try to execute malicious statements that damage the database.  For

+** example, an application may allow a user to enter arbitrary

+** SQL queries for evaluation by a database.  But the application does

+** not want the user to be able to make arbitrary changes to the

+** database.  An authorizer could then be put in place while the

+** user-entered SQL is being [sqlite3_prepare | prepared] that

+** disallows everything except [SELECT] statements.

+**

+** Applications that need to process SQL from untrusted sources

+** might also consider lowering resource limits using [sqlite3_limit()]

+** and limiting database size using the [max_page_count] [PRAGMA]

+** in addition to using an authorizer.

+**

+** Only a single authorizer can be in place on a database connection

+** at a time.  Each call to sqlite3_set_authorizer overrides the

+** previous call.  Disable the authorizer by installing a NULL callback.

+** The authorizer is disabled by default.

+**

+** Note that the authorizer callback is invoked only during

+** [sqlite3_prepare()] or its variants.  Authorization is not

+** performed during statement evaluation in [sqlite3_step()].

+**

+** INVARIANTS:

+**

+** {H12501} The [sqlite3_set_authorizer(D,...)] interface registers a

+**          authorizer callback with database connection D.

+**

+** {H12502} The authorizer callback is invoked as SQL statements are

+**          being compiled.

+**

+** {H12503} If the authorizer callback returns any value other than

+**          [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY], then

+**          the [sqlite3_prepare_v2()] or equivalent call that caused

+**          the authorizer callback to run shall fail with an

+**          [SQLITE_ERROR] error code and an appropriate error message.

+**

+** {H12504} When the authorizer callback returns [SQLITE_OK], the operation

+**          described is processed normally.

+**

+** {H12505} When the authorizer callback returns [SQLITE_DENY], the

+**          [sqlite3_prepare_v2()] or equivalent call that caused the

+**          authorizer callback to run shall fail

+**          with an [SQLITE_ERROR] error code and an error message

+**          explaining that access is denied.

+**

+** {H12506} If the authorizer code (the 2nd parameter to the authorizer

+**          callback) is [SQLITE_READ] and the authorizer callback returns

+**          [SQLITE_IGNORE], then the prepared statement is constructed to

+**          insert a NULL value in place of the table column that would have

+**          been read if [SQLITE_OK] had been returned.

+**

+** {H12507} If the authorizer code (the 2nd parameter to the authorizer

+**          callback) is anything other than [SQLITE_READ], then

+**          a return of [SQLITE_IGNORE] has the same effect as [SQLITE_DENY].

+**

+** {H12510} The first parameter to the authorizer callback is a copy of

+**          the third parameter to the [sqlite3_set_authorizer()] interface.

+**

+** {H12511} The second parameter to the callback is an integer

+**          [SQLITE_COPY | action code] that specifies the particular action

+**          to be authorized.

+**

+** {H12512} The third through sixth parameters to the callback are

+**          zero-terminated strings that contain

+**          additional details about the action to be authorized.

+**

+** {H12520} Each call to [sqlite3_set_authorizer()] overrides

+**          any previously installed authorizer.

+**

+** {H12521} A NULL authorizer means that no authorization

+**          callback is invoked.

+**

+** {H12522} The default authorizer is NULL.

+*/

+int sqlite3_set_authorizer(

+  sqlite3*,

+  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),

+  void *pUserData

+);

+

+/*

+** CAPI3REF: Authorizer Return Codes {H12590} <H12500>

+**

+** The [sqlite3_set_authorizer | authorizer callback function] must

+** return either [SQLITE_OK] or one of these two constants in order

+** to signal SQLite whether or not the action is permitted.  See the

+** [sqlite3_set_authorizer | authorizer documentation] for additional

+** information.

+*/

+#define SQLITE_DENY   1   /* Abort the SQL statement with an error */

+#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */

+

+/*

+** CAPI3REF: Authorizer Action Codes {H12550} <H12500>

+**

+** The [sqlite3_set_authorizer()] interface registers a callback function

+** that is invoked to authorize certain SQL statement actions.  The

+** second parameter to the callback is an integer code that specifies

+** what action is being authorized.  These are the integer action codes that

+** the authorizer callback may be passed.

+**

+** These action code values signify what kind of operation is to be

+** authorized.  The 3rd and 4th parameters to the authorization

+** callback function will be parameters or NULL depending on which of these

+** codes is used as the second parameter.  The 5th parameter to the

+** authorizer callback is the name of the database ("main", "temp",

+** etc.) if applicable.  The 6th parameter to the authorizer callback

+** is the name of the inner-most trigger or view that is responsible for

+** the access attempt or NULL if this access attempt is directly from

+** top-level SQL code.

+**

+** INVARIANTS:

+**

+** {H12551} The second parameter to an

+**          [sqlite3_set_authorizer | authorizer callback] is always an integer

+**          [SQLITE_COPY | authorizer code] that specifies what action

+**          is being authorized.

+**

+** {H12552} The 3rd and 4th parameters to the

+**          [sqlite3_set_authorizer | authorization callback]

+**          will be parameters or NULL depending on which

+**          [SQLITE_COPY | authorizer code] is used as the second parameter.

+**

+** {H12553} The 5th parameter to the

+**          [sqlite3_set_authorizer | authorizer callback] is the name

+**          of the database (example: "main", "temp", etc.) if applicable.

+**

+** {H12554} The 6th parameter to the

+**          [sqlite3_set_authorizer | authorizer callback] is the name

+**          of the inner-most trigger or view that is responsible for

+**          the access attempt or NULL if this access attempt is directly from

+**          top-level SQL code.

+*/

+/******************************************* 3rd ************ 4th ***********/

+#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */

+#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */

+#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */

+#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */

+#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */

+#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */

+#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */

+#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */

+#define SQLITE_DELETE                9   /* Table Name      NULL            */

+#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */

+#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */

+#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */

+#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */

+#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */

+#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */

+#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */

+#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */

+#define SQLITE_INSERT               18   /* Table Name      NULL            */

+#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */

+#define SQLITE_READ                 20   /* Table Name      Column Name     */

+#define SQLITE_SELECT               21   /* NULL            NULL            */

+#define SQLITE_TRANSACTION          22   /* NULL            NULL            */

+#define SQLITE_UPDATE               23   /* Table Name      Column Name     */

+#define SQLITE_ATTACH               24   /* Filename        NULL            */

+#define SQLITE_DETACH               25   /* Database Name   NULL            */

+#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */

+#define SQLITE_REINDEX              27   /* Index Name      NULL            */

+#define SQLITE_ANALYZE              28   /* Table Name      NULL            */

+#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */

+#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */

+#define SQLITE_FUNCTION             31   /* Function Name   NULL            */

+#define SQLITE_COPY                  0   /* No longer used */

+

+/*

+** CAPI3REF: Tracing And Profiling Functions {H12280} <S60400>

+** EXPERIMENTAL

+**

+** These routines register callback functions that can be used for

+** tracing and profiling the execution of SQL statements.

+**

+** The callback function registered by sqlite3_trace() is invoked at

+** various times when an SQL statement is being run by [sqlite3_step()].

+** The callback returns a UTF-8 rendering of the SQL statement text

+** as the statement first begins executing.  Additional callbacks occur

+** as each triggered subprogram is entered.  The callbacks for triggers

+** contain a UTF-8 SQL comment that identifies the trigger.

+**

+** The callback function registered by sqlite3_profile() is invoked

+** as each SQL statement finishes.  The profile callback contains

+** the original statement text and an estimate of wall-clock time

+** of how long that statement took to run.

+**

+** INVARIANTS:

+**

+** {H12281} The callback function registered by [sqlite3_trace()] is

+**          whenever an SQL statement first begins to execute and

+**          whenever a trigger subprogram first begins to run.

+**

+** {H12282} Each call to [sqlite3_trace()] overrides the previously

+**          registered trace callback.

+**

+** {H12283} A NULL trace callback disables tracing.

+**

+** {H12284} The first argument to the trace callback is a copy of

+**          the pointer which was the 3rd argument to [sqlite3_trace()].

+**

+** {H12285} The second argument to the trace callback is a

+**          zero-terminated UTF-8 string containing the original text

+**          of the SQL statement as it was passed into [sqlite3_prepare_v2()]

+**          or the equivalent, or an SQL comment indicating the beginning

+**          of a trigger subprogram.

+**

+** {H12287} The callback function registered by [sqlite3_profile()] is invoked

+**          as each SQL statement finishes.

+**

+** {H12288} The first parameter to the profile callback is a copy of

+**          the 3rd parameter to [sqlite3_profile()].

+**

+** {H12289} The second parameter to the profile callback is a

+**          zero-terminated UTF-8 string that contains the complete text of

+**          the SQL statement as it was processed by [sqlite3_prepare_v2()]

+**          or the equivalent.

+**

+** {H12290} The third parameter to the profile callback is an estimate

+**          of the number of nanoseconds of wall-clock time required to

+**          run the SQL statement from start to finish.

+*/

+void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);

+void *sqlite3_profile(sqlite3*,

+   void(*xProfile)(void*,const char*,sqlite3_uint64), void*);

+

+/*

+** CAPI3REF: Query Progress Callbacks {H12910} <S60400>

+**

+** This routine configures a callback function - the

+** progress callback - that is invoked periodically during long

+** running calls to [sqlite3_exec()], [sqlite3_step()] and

+** [sqlite3_get_table()].  An example use for this

+** interface is to keep a GUI updated during a large query.

+**

+** If the progress callback returns non-zero, the operation is

+** interrupted.  This feature can be used to implement a

+** "Cancel" button on a GUI dialog box.

+**

+** INVARIANTS:

+**

+** {H12911} The callback function registered by sqlite3_progress_handler()

+**          is invoked periodically during long running calls to

+**          [sqlite3_step()].

+**

+** {H12912} The progress callback is invoked once for every N virtual

+**          machine opcodes, where N is the second argument to

+**          the [sqlite3_progress_handler()] call that registered

+**          the callback.  If N is less than 1, sqlite3_progress_handler()

+**          acts as if a NULL progress handler had been specified.

+**

+** {H12913} The progress callback itself is identified by the third

+**          argument to sqlite3_progress_handler().

+**

+** {H12914} The fourth argument to sqlite3_progress_handler() is a

+**          void pointer passed to the progress callback

+**          function each time it is invoked.

+**

+** {H12915} If a call to [sqlite3_step()] results in fewer than N opcodes

+**          being executed, then the progress callback is never invoked.

+**

+** {H12916} Every call to [sqlite3_progress_handler()]

+**          overwrites any previously registered progress handler.

+**

+** {H12917} If the progress handler callback is NULL then no progress

+**          handler is invoked.

+**

+** {H12918} If the progress callback returns a result other than 0, then

+**          the behavior is a if [sqlite3_interrupt()] had been called.

+**          <S30500>

+*/

+void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);

+

+/*

+** CAPI3REF: Opening A New Database Connection {H12700} <S40200>

+**

+** These routines open an SQLite database file whose name is given by the

+** filename argument. The filename argument is interpreted as UTF-8 for

+** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte

+** order for sqlite3_open16(). A [database connection] handle is usually

+** returned in *ppDb, even if an error occurs.  The only exception is that

+** if SQLite is unable to allocate memory to hold the [sqlite3] object,

+** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]

+** object. If the database is opened (and/or created) successfully, then

+** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.  The

+** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain

+** an English language description of the error.

+**

+** The default encoding for the database will be UTF-8 if

+** sqlite3_open() or sqlite3_open_v2() is called and

+** UTF-16 in the native byte order if sqlite3_open16() is used.

+**

+** Whether or not an error occurs when it is opened, resources

+** associated with the [database connection] handle should be released by

+** passing it to [sqlite3_close()] when it is no longer required.

+**

+** The sqlite3_open_v2() interface works like sqlite3_open()

+** except that it accepts two additional parameters for additional control

+** over the new database connection.  The flags parameter can take one of

+** the following three values, optionally combined with the 

+** [SQLITE_OPEN_NOMUTEX] flag:

+**

+** <dl>

+** <dt>[SQLITE_OPEN_READONLY]</dt>

+** <dd>The database is opened in read-only mode.  If the database does not

+** already exist, an error is returned.</dd>

+**

+** <dt>[SQLITE_OPEN_READWRITE]</dt>

+** <dd>The database is opened for reading and writing if possible, or reading

+** only if the file is write protected by the operating system.  In either

+** case the database must already exist, otherwise an error is returned.</dd>

+**

+** <dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>

+** <dd>The database is opened for reading and writing, and is creates it if

+** it does not already exist. This is the behavior that is always used for

+** sqlite3_open() and sqlite3_open16().</dd>

+** </dl>

+**

+** If the 3rd parameter to sqlite3_open_v2() is not one of the

+** combinations shown above or one of the combinations shown above combined

+** with the [SQLITE_OPEN_NOMUTEX] flag, then the behavior is undefined.

+**

+** If the [SQLITE_OPEN_NOMUTEX] flag is set, then mutexes on the

+** opened [database connection] are disabled and the appliation must

+** insure that access to the [database connection] and its associated

+** [prepared statements] is serialized.  The [SQLITE_OPEN_NOMUTEX] flag

+** is the default behavior is SQLite is configured using the

+** [SQLITE_CONFIG_MULTITHREAD] or [SQLITE_CONFIG_SINGLETHREAD] options

+** to [sqlite3_config()].  The [SQLITE_OPEN_NOMUTEX] flag only makes a

+** difference when SQLite is in its default [SQLITE_CONFIG_SERIALIZED] mode.

+**

+** If the filename is ":memory:", then a private, temporary in-memory database

+** is created for the connection.  This in-memory database will vanish when

+** the database connection is closed.  Future versions of SQLite might

+** make use of additional special filenames that begin with the ":" character.

+** It is recommended that when a database filename actually does begin with

+** a ":" character you should prefix the filename with a pathname such as

+** "./" to avoid ambiguity.

+**

+** If the filename is an empty string, then a private, temporary

+** on-disk database will be created.  This private database will be

+** automatically deleted as soon as the database connection is closed.

+**

+** The fourth parameter to sqlite3_open_v2() is the name of the

+** [sqlite3_vfs] object that defines the operating system interface that

+** the new database connection should use.  If the fourth parameter is

+** a NULL pointer then the default [sqlite3_vfs] object is used.

+**

+** <b>Note to Windows users:</b>  The encoding used for the filename argument

+** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever

+** codepage is currently defined.  Filenames containing international

+** characters must be converted to UTF-8 prior to passing them into

+** sqlite3_open() or sqlite3_open_v2().

+**

+** INVARIANTS:

+**

+** {H12701} The [sqlite3_open()], [sqlite3_open16()], and

+**          [sqlite3_open_v2()] interfaces create a new

+**          [database connection] associated with

+**          the database file given in their first parameter.

+**

+** {H12702} The filename argument is interpreted as UTF-8

+**          for [sqlite3_open()] and [sqlite3_open_v2()] and as UTF-16

+**          in the native byte order for [sqlite3_open16()].

+**

+** {H12703} A successful invocation of [sqlite3_open()], [sqlite3_open16()],

+**          or [sqlite3_open_v2()] writes a pointer to a new

+**          [database connection] into *ppDb.

+**

+** {H12704} The [sqlite3_open()], [sqlite3_open16()], and

+**          [sqlite3_open_v2()] interfaces return [SQLITE_OK] upon success,

+**          or an appropriate [error code] on failure.

+**

+** {H12706} The default text encoding for a new database created using

+**          [sqlite3_open()] or [sqlite3_open_v2()] will be UTF-8.

+**

+** {H12707} The default text encoding for a new database created using

+**          [sqlite3_open16()] will be UTF-16.

+**

+** {H12709} The [sqlite3_open(F,D)] interface is equivalent to

+**          [sqlite3_open_v2(F,D,G,0)] where the G parameter is

+**          [SQLITE_OPEN_READWRITE]|[SQLITE_OPEN_CREATE].

+**

+** {H12711} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the

+**          bit value [SQLITE_OPEN_READONLY] then the database is opened

+**          for reading only.

+**

+** {H12712} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the

+**          bit value [SQLITE_OPEN_READWRITE] then the database is opened

+**          reading and writing if possible, or for reading only if the

+**          file is write protected by the operating system.

+**

+** {H12713} If the G parameter to [sqlite3_open_v2(F,D,G,V)] omits the

+**          bit value [SQLITE_OPEN_CREATE] and the database does not

+**          previously exist, an error is returned.

+**

+** {H12714} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the

+**          bit value [SQLITE_OPEN_CREATE] and the database does not

+**          previously exist, then an attempt is made to create and

+**          initialize the database.

+**

+** {H12717} If the filename argument to [sqlite3_open()], [sqlite3_open16()],

+**          or [sqlite3_open_v2()] is ":memory:", then an private,

+**          ephemeral, in-memory database is created for the connection.

+**          <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required

+**          in sqlite3_open_v2()?</todo>

+**

+** {H12719} If the filename is NULL or an empty string, then a private,

+**          ephemeral on-disk database will be created.

+**          <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required

+**          in sqlite3_open_v2()?</todo>

+**

+** {H12721} The [database connection] created by [sqlite3_open_v2(F,D,G,V)]

+**          will use the [sqlite3_vfs] object identified by the V parameter,

+**          or the default [sqlite3_vfs] object if V is a NULL pointer.

+**

+** {H12723} Two [database connections] will share a common cache if both were

+**          opened with the same VFS while [shared cache mode] was enabled and

+**          if both filenames compare equal using memcmp() after having been

+**          processed by the [sqlite3_vfs | xFullPathname] method of the VFS.

+*/

+int sqlite3_open(

+  const char *filename,   /* Database filename (UTF-8) */

+  sqlite3 **ppDb          /* OUT: SQLite db handle */

+);

+int sqlite3_open16(

+  const void *filename,   /* Database filename (UTF-16) */

+  sqlite3 **ppDb          /* OUT: SQLite db handle */

+);

+int sqlite3_open_v2(

+  const char *filename,   /* Database filename (UTF-8) */

+  sqlite3 **ppDb,         /* OUT: SQLite db handle */

+  int flags,              /* Flags */

+  const char *zVfs        /* Name of VFS module to use */

+);

+

+/*

+** CAPI3REF: Error Codes And Messages {H12800} <S60200>

+**

+** The sqlite3_errcode() interface returns the numeric [result code] or

+** [extended result code] for the most recent failed sqlite3_* API call

+** associated with a [database connection]. If a prior API call failed

+** but the most recent API call succeeded, the return value from

+** sqlite3_errcode() is undefined.

+**

+** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language

+** text that describes the error, as either UTF-8 or UTF-16 respectively.

+** Memory to hold the error message string is managed internally.

+** The application does not need to worry about freeing the result.

+** However, the error string might be overwritten or deallocated by

+** subsequent calls to other SQLite interface functions.

+**

+** If an interface fails with SQLITE_MISUSE, that means the interface

+** was invoked incorrectly by the application.  In that case, the

+** error code and message may or may not be set.

+**

+** INVARIANTS:

+**

+** {H12801} The [sqlite3_errcode(D)] interface returns the numeric

+**          [result code] or [extended result code] for the most recently

+**          failed interface call associated with the [database connection] D.

+**

+** {H12803} The [sqlite3_errmsg(D)] and [sqlite3_errmsg16(D)]

+**          interfaces return English-language text that describes

+**          the error in the mostly recently failed interface call,

+**          encoded as either UTF-8 or UTF-16 respectively.

+**

+** {H12807} The strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()]

+**          are valid until the next SQLite interface call.

+**

+** {H12808} Calls to API routines that do not return an error code

+**          (example: [sqlite3_data_count()]) do not

+**          change the error code or message returned by

+**          [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()].

+**

+** {H12809} Interfaces that are not associated with a specific

+**          [database connection] (examples:

+**          [sqlite3_mprintf()] or [sqlite3_enable_shared_cache()]

+**          do not change the values returned by

+**          [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()].

+*/

+int sqlite3_errcode(sqlite3 *db);

+const char *sqlite3_errmsg(sqlite3*);

+const void *sqlite3_errmsg16(sqlite3*);

+

+/*

+** CAPI3REF: SQL Statement Object {H13000} <H13010>

+** KEYWORDS: {prepared statement} {prepared statements}

+**

+** An instance of this object represents a single SQL statement.

+** This object is variously known as a "prepared statement" or a

+** "compiled SQL statement" or simply as a "statement".

+**

+** The life of a statement object goes something like this:

+**

+** <ol>

+** <li> Create the object using [sqlite3_prepare_v2()] or a related

+**      function.

+** <li> Bind values to [host parameters] using the sqlite3_bind_*()

+**      interfaces.

+** <li> Run the SQL by calling [sqlite3_step()] one or more times.

+** <li> Reset the statement using [sqlite3_reset()] then go back

+**      to step 2.  Do this zero or more times.

+** <li> Destroy the object using [sqlite3_finalize()].

+** </ol>

+**

+** Refer to documentation on individual methods above for additional

+** information.

+*/

+typedef struct sqlite3_stmt sqlite3_stmt;

+

+/*

+** CAPI3REF: Run-time Limits {H12760} <S20600>

+**

+** This interface allows the size of various constructs to be limited

+** on a connection by connection basis.  The first parameter is the

+** [database connection] whose limit is to be set or queried.  The

+** second parameter is one of the [limit categories] that define a

+** class of constructs to be size limited.  The third parameter is the

+** new limit for that construct.  The function returns the old limit.

+**

+** If the new limit is a negative number, the limit is unchanged.

+** For the limit category of SQLITE_LIMIT_XYZ there is a hard upper

+** bound set by a compile-time C preprocessor macro named SQLITE_MAX_XYZ.

+** (The "_LIMIT_" in the name is changed to "_MAX_".)

+** Attempts to increase a limit above its hard upper bound are

+** silently truncated to the hard upper limit.

+**

+** Run time limits are intended for use in applications that manage

+** both their own internal database and also databases that are controlled

+** by untrusted external sources.  An example application might be a

+** webbrowser that has its own databases for storing history and

+** separate databases controlled by JavaScript applications downloaded

+** off the Internet.  The internal databases can be given the

+** large, default limits.  Databases managed by external sources can

+** be given much smaller limits designed to prevent a denial of service

+** attack.  Developers might also want to use the [sqlite3_set_authorizer()]

+** interface to further control untrusted SQL.  The size of the database

+** created by an untrusted script can be contained using the

+** [max_page_count] [PRAGMA].

+**

+** New run-time limit categories may be added in future releases.

+**

+** INVARIANTS:

+**

+** {H12762} A successful call to [sqlite3_limit(D,C,V)] where V is

+**          positive changes the limit on the size of construct C in the

+**          [database connection] D to the lesser of V and the hard upper

+**          bound on the size of C that is set at compile-time.

+**

+** {H12766} A successful call to [sqlite3_limit(D,C,V)] where V is negative

+**          leaves the state of the [database connection] D unchanged.

+**

+** {H12769} A successful call to [sqlite3_limit(D,C,V)] returns the

+**          value of the limit on the size of construct C in the

+**          [database connection] D as it was prior to the call.

+*/

+int sqlite3_limit(sqlite3*, int id, int newVal);

+

+/*

+** CAPI3REF: Run-Time Limit Categories {H12790} <H12760>

+** KEYWORDS: {limit category} {limit categories}

+**

+** These constants define various aspects of a [database connection]

+** that can be limited in size by calls to [sqlite3_limit()].

+** The meanings of the various limits are as follows:

+**

+** <dl>

+** <dt>SQLITE_LIMIT_LENGTH</dt>

+** <dd>The maximum size of any string or BLOB or table row.<dd>

+**

+** <dt>SQLITE_LIMIT_SQL_LENGTH</dt>

+** <dd>The maximum length of an SQL statement.</dd>

+**

+** <dt>SQLITE_LIMIT_COLUMN</dt>

+** <dd>The maximum number of columns in a table definition or in the

+** result set of a SELECT or the maximum number of columns in an index

+** or in an ORDER BY or GROUP BY clause.</dd>

+**

+** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt>

+** <dd>The maximum depth of the parse tree on any expression.</dd>

+**

+** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>

+** <dd>The maximum number of terms in a compound SELECT statement.</dd>

+**

+** <dt>SQLITE_LIMIT_VDBE_OP</dt>

+** <dd>The maximum number of instructions in a virtual machine program

+** used to implement an SQL statement.</dd>

+**

+** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt>

+** <dd>The maximum number of arguments on a function.</dd>

+**

+** <dt>SQLITE_LIMIT_ATTACHED</dt>

+** <dd>The maximum number of attached databases.</dd>

+**

+** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>

+** <dd>The maximum length of the pattern argument to the LIKE or

+** GLOB operators.</dd>

+**

+** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>

+** <dd>The maximum number of variables in an SQL statement that can

+** be bound.</dd>

+** </dl>

+*/

+#define SQLITE_LIMIT_LENGTH                    0

+#define SQLITE_LIMIT_SQL_LENGTH                1

+#define SQLITE_LIMIT_COLUMN                    2

+#define SQLITE_LIMIT_EXPR_DEPTH                3

+#define SQLITE_LIMIT_COMPOUND_SELECT           4

+#define SQLITE_LIMIT_VDBE_OP                   5

+#define SQLITE_LIMIT_FUNCTION_ARG              6

+#define SQLITE_LIMIT_ATTACHED                  7

+#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8

+#define SQLITE_LIMIT_VARIABLE_NUMBER           9

+

+/*

+** CAPI3REF: Compiling An SQL Statement {H13010} <S10000>

+** KEYWORDS: {SQL statement compiler}

+**

+** To execute an SQL query, it must first be compiled into a byte-code

+** program using one of these routines.

+**

+** The first argument, "db", is a [database connection] obtained from a

+** prior call to [sqlite3_open()], [sqlite3_open_v2()] or [sqlite3_open16()].

+**

+** The second argument, "zSql", is the statement to be compiled, encoded

+** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()

+** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()

+** use UTF-16.

+**

+** If the nByte argument is less than zero, then zSql is read up to the

+** first zero terminator. If nByte is non-negative, then it is the maximum

+** number of  bytes read from zSql.  When nByte is non-negative, the

+** zSql string ends at either the first '\000' or '\u0000' character or

+** the nByte-th byte, whichever comes first. If the caller knows

+** that the supplied string is nul-terminated, then there is a small

+** performance advantage to be gained by passing an nByte parameter that

+** is equal to the number of bytes in the input string <i>including</i>

+** the nul-terminator bytes.

+**

+** *pzTail is made to point to the first byte past the end of the

+** first SQL statement in zSql.  These routines only compile the first

+** statement in zSql, so *pzTail is left pointing to what remains

+** uncompiled.

+**

+** *ppStmt is left pointing to a compiled [prepared statement] that can be

+** executed using [sqlite3_step()].  If there is an error, *ppStmt is set

+** to NULL.  If the input text contains no SQL (if the input is an empty

+** string or a comment) then *ppStmt is set to NULL.

+** {A13018} The calling procedure is responsible for deleting the compiled

+** SQL statement using [sqlite3_finalize()] after it has finished with it.

+**

+** On success, [SQLITE_OK] is returned, otherwise an [error code] is returned.

+**

+** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are

+** recommended for all new programs. The two older interfaces are retained

+** for backwards compatibility, but their use is discouraged.

+** In the "v2" interfaces, the prepared statement

+** that is returned (the [sqlite3_stmt] object) contains a copy of the

+** original SQL text. This causes the [sqlite3_step()] interface to

+** behave a differently in two ways:

+**

+** <ol>

+** <li>

+** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it

+** always used to do, [sqlite3_step()] will automatically recompile the SQL

+** statement and try to run it again.  If the schema has changed in

+** a way that makes the statement no longer valid, [sqlite3_step()] will still

+** return [SQLITE_SCHEMA].  But unlike the legacy behavior, [SQLITE_SCHEMA] is

+** now a fatal error.  Calling [sqlite3_prepare_v2()] again will not make the

+** error go away.  Note: use [sqlite3_errmsg()] to find the text

+** of the parsing error that results in an [SQLITE_SCHEMA] return.

+** </li>

+**

+** <li>

+** When an error occurs, [sqlite3_step()] will return one of the detailed

+** [error codes] or [extended error codes].  The legacy behavior was that

+** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code

+** and you would have to make a second call to [sqlite3_reset()] in order

+** to find the underlying cause of the problem. With the "v2" prepare

+** interfaces, the underlying reason for the error is returned immediately.

+** </li>

+** </ol>

+**

+** INVARIANTS:

+**

+** {H13011} The [sqlite3_prepare(db,zSql,...)] and

+**          [sqlite3_prepare_v2(db,zSql,...)] interfaces interpret the

+**          text in their zSql parameter as UTF-8.

+**

+** {H13012} The [sqlite3_prepare16(db,zSql,...)] and

+**          [sqlite3_prepare16_v2(db,zSql,...)] interfaces interpret the

+**          text in their zSql parameter as UTF-16 in the native byte order.

+**

+** {H13013} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)]

+**          and its variants is less than zero, the SQL text is

+**          read from zSql is read up to the first zero terminator.

+**

+** {H13014} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)]

+**          and its variants is non-negative, then at most nBytes bytes of

+**          SQL text is read from zSql.

+**

+** {H13015} In [sqlite3_prepare_v2(db,zSql,N,P,pzTail)] and its variants

+**          if the zSql input text contains more than one SQL statement

+**          and pzTail is not NULL, then *pzTail is made to point to the

+**          first byte past the end of the first SQL statement in zSql.

+**          <todo>What does *pzTail point to if there is one statement?</todo>

+**

+** {H13016} A successful call to [sqlite3_prepare_v2(db,zSql,N,ppStmt,...)]

+**          or one of its variants writes into *ppStmt a pointer to a new

+**          [prepared statement] or a pointer to NULL if zSql contains

+**          nothing other than whitespace or comments.

+**

+** {H13019} The [sqlite3_prepare_v2()] interface and its variants return

+**          [SQLITE_OK] or an appropriate [error code] upon failure.

+**

+** {H13021} Before [sqlite3_prepare(db,zSql,nByte,ppStmt,pzTail)] or its

+**          variants returns an error (any value other than [SQLITE_OK]),

+**          they first set *ppStmt to NULL.

+*/

+int sqlite3_prepare(

+  sqlite3 *db,            /* Database handle */

+  const char *zSql,       /* SQL statement, UTF-8 encoded */

+  int nByte,              /* Maximum length of zSql in bytes. */

+  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */

+  const char **pzTail     /* OUT: Pointer to unused portion of zSql */

+);

+int sqlite3_prepare_v2(

+  sqlite3 *db,            /* Database handle */

+  const char *zSql,       /* SQL statement, UTF-8 encoded */

+  int nByte,              /* Maximum length of zSql in bytes. */

+  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */

+  const char **pzTail     /* OUT: Pointer to unused portion of zSql */

+);

+int sqlite3_prepare16(

+  sqlite3 *db,            /* Database handle */

+  const void *zSql,       /* SQL statement, UTF-16 encoded */

+  int nByte,              /* Maximum length of zSql in bytes. */

+  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */

+  const void **pzTail     /* OUT: Pointer to unused portion of zSql */

+);

+int sqlite3_prepare16_v2(

+  sqlite3 *db,            /* Database handle */

+  const void *zSql,       /* SQL statement, UTF-16 encoded */

+  int nByte,              /* Maximum length of zSql in bytes. */

+  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */

+  const void **pzTail     /* OUT: Pointer to unused portion of zSql */

+);

+

+/*

+** CAPIREF: Retrieving Statement SQL {H13100} <H13000>

+**

+** This interface can be used to retrieve a saved copy of the original

+** SQL text used to create a [prepared statement] if that statement was

+** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].

+**

+** INVARIANTS:

+**

+** {H13101} If the [prepared statement] passed as the argument to

+**          [sqlite3_sql()] was compiled using either [sqlite3_prepare_v2()] or

+**          [sqlite3_prepare16_v2()], then [sqlite3_sql()] returns

+**          a pointer to a zero-terminated string containing a UTF-8 rendering

+**          of the original SQL statement.

+**

+** {H13102} If the [prepared statement] passed as the argument to

+**          [sqlite3_sql()] was compiled using either [sqlite3_prepare()] or

+**          [sqlite3_prepare16()], then [sqlite3_sql()] returns a NULL pointer.

+**

+** {H13103} The string returned by [sqlite3_sql(S)] is valid until the

+**          [prepared statement] S is deleted using [sqlite3_finalize(S)].

+*/

+const char *sqlite3_sql(sqlite3_stmt *pStmt);

+

+/*

+** CAPI3REF: Dynamically Typed Value Object {H15000} <S20200>

+** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}

+**

+** SQLite uses the sqlite3_value object to represent all values

+** that can be stored in a database table. SQLite uses dynamic typing

+** for the values it stores. Values stored in sqlite3_value objects

+** can be integers, floating point values, strings, BLOBs, or NULL.

+**

+** An sqlite3_value object may be either "protected" or "unprotected".

+** Some interfaces require a protected sqlite3_value.  Other interfaces

+** will accept either a protected or an unprotected sqlite3_value.

+** Every interface that accepts sqlite3_value arguments specifies

+** whether or not it requires a protected sqlite3_value.

+**

+** The terms "protected" and "unprotected" refer to whether or not

+** a mutex is held.  A internal mutex is held for a protected

+** sqlite3_value object but no mutex is held for an unprotected

+** sqlite3_value object.  If SQLite is compiled to be single-threaded

+** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)

+** or if SQLite is run in one of reduced mutex modes 

+** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]

+** then there is no distinction between protected and unprotected

+** sqlite3_value objects and they can be used interchangeably.  However,

+** for maximum code portability it is recommended that applications

+** still make the distinction between between protected and unprotected

+** sqlite3_value objects even when not strictly required.

+**

+** The sqlite3_value objects that are passed as parameters into the

+** implementation of [application-defined SQL functions] are protected.

+** The sqlite3_value object returned by

+** [sqlite3_column_value()] is unprotected.

+** Unprotected sqlite3_value objects may only be used with

+** [sqlite3_result_value()] and [sqlite3_bind_value()].

+** The [sqlite3_value_blob | sqlite3_value_type()] family of

+** interfaces require protected sqlite3_value objects.

+*/

+typedef struct Mem sqlite3_value;

+

+/*

+** CAPI3REF: SQL Function Context Object {H16001} <S20200>

+**

+** The context in which an SQL function executes is stored in an

+** sqlite3_context object.  A pointer to an sqlite3_context object

+** is always first parameter to [application-defined SQL functions].

+** The application-defined SQL function implementation will pass this

+** pointer through into calls to [sqlite3_result_int | sqlite3_result()],

+** [sqlite3_aggregate_context()], [sqlite3_user_data()],

+** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],

+** and/or [sqlite3_set_auxdata()].

+*/

+typedef struct sqlite3_context sqlite3_context;

+

+/*

+** CAPI3REF: Binding Values To Prepared Statements {H13500} <S70300>

+** KEYWORDS: {host parameter} {host parameters} {host parameter name}

+** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}

+**

+** In the SQL strings input to [sqlite3_prepare_v2()] and its variants,

+** literals may be replaced by a parameter in one of these forms:

+**

+** <ul>

+** <li>  ?

+** <li>  ?NNN

+** <li>  :VVV

+** <li>  @VVV

+** <li>  $VVV

+** </ul>

+**

+** In the parameter forms shown above NNN is an integer literal,

+** and VVV is an alpha-numeric parameter name. The values of these

+** parameters (also called "host parameter names" or "SQL parameters")

+** can be set using the sqlite3_bind_*() routines defined here.

+**

+** The first argument to the sqlite3_bind_*() routines is always

+** a pointer to the [sqlite3_stmt] object returned from

+** [sqlite3_prepare_v2()] or its variants.

+**

+** The second argument is the index of the SQL parameter to be set.

+** The leftmost SQL parameter has an index of 1.  When the same named

+** SQL parameter is used more than once, second and subsequent

+** occurrences have the same index as the first occurrence.

+** The index for named parameters can be looked up using the

+** [sqlite3_bind_parameter_index()] API if desired.  The index

+** for "?NNN" parameters is the value of NNN.

+** The NNN value must be between 1 and the [sqlite3_limit()]

+** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).

+**

+** The third argument is the value to bind to the parameter.

+**

+** In those routines that have a fourth argument, its value is the

+** number of bytes in the parameter.  To be clear: the value is the

+** number of <u>bytes</u> in the value, not the number of characters.

+** If the fourth parameter is negative, the length of the string is

+** the number of bytes up to the first zero terminator.

+**

+** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and

+** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or

+** string after SQLite has finished with it. If the fifth argument is

+** the special value [SQLITE_STATIC], then SQLite assumes that the

+** information is in static, unmanaged space and does not need to be freed.

+** If the fifth argument has the value [SQLITE_TRANSIENT], then

+** SQLite makes its own private copy of the data immediately, before

+** the sqlite3_bind_*() routine returns.

+**

+** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that

+** is filled with zeroes.  A zeroblob uses a fixed amount of memory

+** (just an integer to hold its size) while it is being processed.

+** Zeroblobs are intended to serve as placeholders for BLOBs whose

+** content is later written using

+** [sqlite3_blob_open | incremental BLOB I/O] routines.

+** A negative value for the zeroblob results in a zero-length BLOB.

+**

+** The sqlite3_bind_*() routines must be called after

+** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and

+** before [sqlite3_step()].

+** Bindings are not cleared by the [sqlite3_reset()] routine.

+** Unbound parameters are interpreted as NULL.

+**

+** These routines return [SQLITE_OK] on success or an error code if

+** anything goes wrong.  [SQLITE_RANGE] is returned if the parameter

+** index is out of range.  [SQLITE_NOMEM] is returned if malloc() fails.

+** [SQLITE_MISUSE] might be returned if these routines are called on a

+** virtual machine that is the wrong state or which has already been finalized.

+** Detection of misuse is unreliable.  Applications should not depend

+** on SQLITE_MISUSE returns.  SQLITE_MISUSE is intended to indicate a

+** a logic error in the application.  Future versions of SQLite might

+** panic rather than return SQLITE_MISUSE.

+**

+** See also: [sqlite3_bind_parameter_count()],

+** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].

+**

+** INVARIANTS:

+**

+** {H13506} The [SQL statement compiler] recognizes tokens of the forms

+**          "?", "?NNN", "$VVV", ":VVV", and "@VVV" as SQL parameters,

+**          where NNN is any sequence of one or more digits

+**          and where VVV is any sequence of one or more alphanumeric

+**          characters or "::" optionally followed by a string containing

+**          no spaces and contained within parentheses.

+**

+** {H13509} The initial value of an SQL parameter is NULL.

+**

+** {H13512} The index of an "?" SQL parameter is one larger than the

+**          largest index of SQL parameter to the left, or 1 if

+**          the "?" is the leftmost SQL parameter.

+**

+** {H13515} The index of an "?NNN" SQL parameter is the integer NNN.

+**

+** {H13518} The index of an ":VVV", "$VVV", or "@VVV" SQL parameter is

+**          the same as the index of leftmost occurrences of the same

+**          parameter, or one more than the largest index over all

+**          parameters to the left if this is the first occurrence

+**          of this parameter, or 1 if this is the leftmost parameter.

+**

+** {H13521} The [SQL statement compiler] fails with an [SQLITE_RANGE]

+**          error if the index of an SQL parameter is less than 1

+**          or greater than the compile-time SQLITE_MAX_VARIABLE_NUMBER

+**          parameter.

+**

+** {H13524} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,V,...)]

+**          associate the value V with all SQL parameters having an

+**          index of N in the [prepared statement] S.

+**

+** {H13527} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,...)]

+**          override prior calls with the same values of S and N.

+**

+** {H13530} Bindings established by [sqlite3_bind_text | sqlite3_bind(S,...)]

+**          persist across calls to [sqlite3_reset(S)].

+**

+** {H13533} In calls to [sqlite3_bind_blob(S,N,V,L,D)],

+**          [sqlite3_bind_text(S,N,V,L,D)], or

+**          [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds the first L

+**          bytes of the BLOB or string pointed to by V, when L

+**          is non-negative.

+**

+** {H13536} In calls to [sqlite3_bind_text(S,N,V,L,D)] or

+**          [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds characters

+**          from V through the first zero character when L is negative.

+**

+** {H13539} In calls to [sqlite3_bind_blob(S,N,V,L,D)],

+**          [sqlite3_bind_text(S,N,V,L,D)], or

+**          [sqlite3_bind_text16(S,N,V,L,D)] when D is the special

+**          constant [SQLITE_STATIC], SQLite assumes that the value V

+**          is held in static unmanaged space that will not change

+**          during the lifetime of the binding.

+**

+** {H13542} In calls to [sqlite3_bind_blob(S,N,V,L,D)],

+**          [sqlite3_bind_text(S,N,V,L,D)], or

+**          [sqlite3_bind_text16(S,N,V,L,D)] when D is the special

+**          constant [SQLITE_TRANSIENT], the routine makes a

+**          private copy of the value V before it returns.

+**

+** {H13545} In calls to [sqlite3_bind_blob(S,N,V,L,D)],

+**          [sqlite3_bind_text(S,N,V,L,D)], or

+**          [sqlite3_bind_text16(S,N,V,L,D)] when D is a pointer to

+**          a function, SQLite invokes that function to destroy the

+**          value V after it has finished using the value V.

+**

+** {H13548} In calls to [sqlite3_bind_zeroblob(S,N,V,L)] the value bound

+**          is a BLOB of L bytes, or a zero-length BLOB if L is negative.

+**

+** {H13551} In calls to [sqlite3_bind_value(S,N,V)] the V argument may

+**          be either a [protected sqlite3_value] object or an

+**          [unprotected sqlite3_value] object.

+*/

+int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));

+int sqlite3_bind_double(sqlite3_stmt*, int, double);

+int sqlite3_bind_int(sqlite3_stmt*, int, int);

+int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);

+int sqlite3_bind_null(sqlite3_stmt*, int);

+int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));

+int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));

+int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);

+int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);

+

+/*

+** CAPI3REF: Number Of SQL Parameters {H13600} <S70300>

+**

+** This routine can be used to find the number of [SQL parameters]

+** in a [prepared statement].  SQL parameters are tokens of the

+** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as

+** placeholders for values that are [sqlite3_bind_blob | bound]

+** to the parameters at a later time.

+**

+** This routine actually returns the index of the largest (rightmost)

+** parameter. For all forms except ?NNN, this will correspond to the

+** number of unique parameters.  If parameters of the ?NNN are used,

+** there may be gaps in the list.

+**

+** See also: [sqlite3_bind_blob|sqlite3_bind()],

+** [sqlite3_bind_parameter_name()], and

+** [sqlite3_bind_parameter_index()].

+**

+** INVARIANTS:

+**

+** {H13601} The [sqlite3_bind_parameter_count(S)] interface returns

+**          the largest index of all SQL parameters in the

+**          [prepared statement] S, or 0 if S contains no SQL parameters.

+*/

+int sqlite3_bind_parameter_count(sqlite3_stmt*);

+

+/*

+** CAPI3REF: Name Of A Host Parameter {H13620} <S70300>

+**

+** This routine returns a pointer to the name of the n-th

+** [SQL parameter] in a [prepared statement].

+** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"

+** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"

+** respectively.

+** In other words, the initial ":" or "$" or "@" or "?"

+** is included as part of the name.

+** Parameters of the form "?" without a following integer have no name

+** and are also referred to as "anonymous parameters".

+**

+** The first host parameter has an index of 1, not 0.

+**

+** If the value n is out of range or if the n-th parameter is

+** nameless, then NULL is returned.  The returned string is

+** always in UTF-8 encoding even if the named parameter was

+** originally specified as UTF-16 in [sqlite3_prepare16()] or

+** [sqlite3_prepare16_v2()].

+**

+** See also: [sqlite3_bind_blob|sqlite3_bind()],

+** [sqlite3_bind_parameter_count()], and

+** [sqlite3_bind_parameter_index()].

+**

+** INVARIANTS:

+**

+** {H13621} The [sqlite3_bind_parameter_name(S,N)] interface returns

+**          a UTF-8 rendering of the name of the SQL parameter in

+**          the [prepared statement] S having index N, or

+**          NULL if there is no SQL parameter with index N or if the

+**          parameter with index N is an anonymous parameter "?".

+*/

+const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);

+

+/*

+** CAPI3REF: Index Of A Parameter With A Given Name {H13640} <S70300>

+**

+** Return the index of an SQL parameter given its name.  The

+** index value returned is suitable for use as the second

+** parameter to [sqlite3_bind_blob|sqlite3_bind()].  A zero

+** is returned if no matching parameter is found.  The parameter

+** name must be given in UTF-8 even if the original statement

+** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].

+**

+** See also: [sqlite3_bind_blob|sqlite3_bind()],

+** [sqlite3_bind_parameter_count()], and

+** [sqlite3_bind_parameter_index()].

+**

+** INVARIANTS:

+**

+** {H13641} The [sqlite3_bind_parameter_index(S,N)] interface returns

+**          the index of SQL parameter in the [prepared statement]

+**          S whose name matches the UTF-8 string N, or 0 if there is

+**          no match.

+*/

+int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);

+

+/*

+** CAPI3REF: Reset All Bindings On A Prepared Statement {H13660} <S70300>

+**

+** Contrary to the intuition of many, [sqlite3_reset()] does not reset

+** the [sqlite3_bind_blob | bindings] on a [prepared statement].

+** Use this routine to reset all host parameters to NULL.

+**

+** INVARIANTS:

+**

+** {H13661} The [sqlite3_clear_bindings(S)] interface resets all SQL

+**          parameter bindings in the [prepared statement] S back to NULL.

+*/

+int sqlite3_clear_bindings(sqlite3_stmt*);

+

+/*

+** CAPI3REF: Number Of Columns In A Result Set {H13710} <S10700>

+**

+** Return the number of columns in the result set returned by the

+** [prepared statement]. This routine returns 0 if pStmt is an SQL

+** statement that does not return data (for example an [UPDATE]).

+**

+** INVARIANTS:

+**

+** {H13711} The [sqlite3_column_count(S)] interface returns the number of

+**          columns in the result set generated by the [prepared statement] S,

+**          or 0 if S does not generate a result set.

+*/

+int sqlite3_column_count(sqlite3_stmt *pStmt);

+

+/*

+** CAPI3REF: Column Names In A Result Set {H13720} <S10700>

+**

+** These routines return the name assigned to a particular column

+** in the result set of a [SELECT] statement.  The sqlite3_column_name()

+** interface returns a pointer to a zero-terminated UTF-8 string

+** and sqlite3_column_name16() returns a pointer to a zero-terminated

+** UTF-16 string.  The first parameter is the [prepared statement]

+** that implements the [SELECT] statement. The second parameter is the

+** column number.  The leftmost column is number 0.

+**

+** The returned string pointer is valid until either the [prepared statement]

+** is destroyed by [sqlite3_finalize()] or until the next call to

+** sqlite3_column_name() or sqlite3_column_name16() on the same column.

+**

+** If sqlite3_malloc() fails during the processing of either routine

+** (for example during a conversion from UTF-8 to UTF-16) then a

+** NULL pointer is returned.

+**

+** The name of a result column is the value of the "AS" clause for

+** that column, if there is an AS clause.  If there is no AS clause

+** then the name of the column is unspecified and may change from

+** one release of SQLite to the next.

+**

+** INVARIANTS:

+**

+** {H13721} A successful invocation of the [sqlite3_column_name(S,N)]

+**          interface returns the name of the Nth column (where 0 is

+**          the leftmost column) for the result set of the

+**          [prepared statement] S as a zero-terminated UTF-8 string.

+**

+** {H13723} A successful invocation of the [sqlite3_column_name16(S,N)]

+**          interface returns the name of the Nth column (where 0 is

+**          the leftmost column) for the result set of the

+**          [prepared statement] S as a zero-terminated UTF-16 string

+**          in the native byte order.

+**

+** {H13724} The [sqlite3_column_name()] and [sqlite3_column_name16()]

+**          interfaces return a NULL pointer if they are unable to

+**          allocate memory to hold their normal return strings.

+**

+** {H13725} If the N parameter to [sqlite3_column_name(S,N)] or

+**          [sqlite3_column_name16(S,N)] is out of range, then the

+**          interfaces return a NULL pointer.

+**

+** {H13726} The strings returned by [sqlite3_column_name(S,N)] and

+**          [sqlite3_column_name16(S,N)] are valid until the next

+**          call to either routine with the same S and N parameters

+**          or until [sqlite3_finalize(S)] is called.

+**

+** {H13727} When a result column of a [SELECT] statement contains

+**          an AS clause, the name of that column is the identifier

+**          to the right of the AS keyword.

+*/

+const char *sqlite3_column_name(sqlite3_stmt*, int N);

+const void *sqlite3_column_name16(sqlite3_stmt*, int N);

+

+/*

+** CAPI3REF: Source Of Data In A Query Result {H13740} <S10700>

+**

+** These routines provide a means to determine what column of what

+** table in which database a result of a [SELECT] statement comes from.

+** The name of the database or table or column can be returned as

+** either a UTF-8 or UTF-16 string.  The _database_ routines return

+** the database name, the _table_ routines return the table name, and

+** the origin_ routines return the column name.

+** The returned string is valid until the [prepared statement] is destroyed

+** using [sqlite3_finalize()] or until the same information is requested

+** again in a different encoding.

+**

+** The names returned are the original un-aliased names of the

+** database, table, and column.

+**

+** The first argument to the following calls is a [prepared statement].

+** These functions return information about the Nth column returned by

+** the statement, where N is the second function argument.

+**

+** If the Nth column returned by the statement is an expression or

+** subquery and is not a column value, then all of these functions return

+** NULL.  These routine might also return NULL if a memory allocation error

+** occurs.  Otherwise, they return the name of the attached database, table

+** and column that query result column was extracted from.

+**

+** As with all other SQLite APIs, those postfixed with "16" return

+** UTF-16 encoded strings, the other functions return UTF-8. {END}

+**

+** These APIs are only available if the library was compiled with the

+** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.

+**

+** {A13751}

+** If two or more threads call one or more of these routines against the same

+** prepared statement and column at the same time then the results are

+** undefined.

+**

+** INVARIANTS:

+**

+** {H13741} The [sqlite3_column_database_name(S,N)] interface returns either

+**          the UTF-8 zero-terminated name of the database from which the

+**          Nth result column of the [prepared statement] S is extracted,

+**          or NULL if the Nth column of S is a general expression

+**          or if unable to allocate memory to store the name.

+**

+** {H13742} The [sqlite3_column_database_name16(S,N)] interface returns either

+**          the UTF-16 native byte order zero-terminated name of the database

+**          from which the Nth result column of the [prepared statement] S is

+**          extracted, or NULL if the Nth column of S is a general expression

+**          or if unable to allocate memory to store the name.

+**

+** {H13743} The [sqlite3_column_table_name(S,N)] interface returns either

+**          the UTF-8 zero-terminated name of the table from which the

+**          Nth result column of the [prepared statement] S is extracted,

+**          or NULL if the Nth column of S is a general expression

+**          or if unable to allocate memory to store the name.

+**

+** {H13744} The [sqlite3_column_table_name16(S,N)] interface returns either

+**          the UTF-16 native byte order zero-terminated name of the table

+**          from which the Nth result column of the [prepared statement] S is

+**          extracted, or NULL if the Nth column of S is a general expression

+**          or if unable to allocate memory to store the name.

+**

+** {H13745} The [sqlite3_column_origin_name(S,N)] interface returns either

+**          the UTF-8 zero-terminated name of the table column from which the

+**          Nth result column of the [prepared statement] S is extracted,

+**          or NULL if the Nth column of S is a general expression

+**          or if unable to allocate memory to store the name.

+**

+** {H13746} The [sqlite3_column_origin_name16(S,N)] interface returns either

+**          the UTF-16 native byte order zero-terminated name of the table

+**          column from which the Nth result column of the

+**          [prepared statement] S is extracted, or NULL if the Nth column

+**          of S is a general expression or if unable to allocate memory

+**          to store the name.

+**

+** {H13748} The return values from

+**          [sqlite3_column_database_name | column metadata interfaces]

+**          are valid for the lifetime of the [prepared statement]

+**          or until the encoding is changed by another metadata

+**          interface call for the same prepared statement and column.

+**

+** ASSUMPTIONS:

+**

+** {A13751} If two or more threads call one or more

+**          [sqlite3_column_database_name | column metadata interfaces]

+**          for the same [prepared statement] and result column

+**          at the same time then the results are undefined.

+*/

+const char *sqlite3_column_database_name(sqlite3_stmt*,int);

+const void *sqlite3_column_database_name16(sqlite3_stmt*,int);

+const char *sqlite3_column_table_name(sqlite3_stmt*,int);

+const void *sqlite3_column_table_name16(sqlite3_stmt*,int);

+const char *sqlite3_column_origin_name(sqlite3_stmt*,int);

+const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);

+

+/*

+** CAPI3REF: Declared Datatype Of A Query Result {H13760} <S10700>

+**

+** The first parameter is a [prepared statement].

+** If this statement is a [SELECT] statement and the Nth column of the

+** returned result set of that [SELECT] is a table column (not an

+** expression or subquery) then the declared type of the table

+** column is returned.  If the Nth column of the result set is an

+** expression or subquery, then a NULL pointer is returned.

+** The returned string is always UTF-8 encoded. {END}

+**

+** For example, given the database schema:

+**

+** CREATE TABLE t1(c1 VARIANT);

+**

+** and the following statement to be compiled:

+**

+** SELECT c1 + 1, c1 FROM t1;

+**

+** this routine would return the string "VARIANT" for the second result

+** column (i==1), and a NULL pointer for the first result column (i==0).

+**

+** SQLite uses dynamic run-time typing.  So just because a column

+** is declared to contain a particular type does not mean that the

+** data stored in that column is of the declared type.  SQLite is

+** strongly typed, but the typing is dynamic not static.  Type

+** is associated with individual values, not with the containers

+** used to hold those values.

+**

+** INVARIANTS:

+**

+** {H13761}  A successful call to [sqlite3_column_decltype(S,N)] returns a

+**           zero-terminated UTF-8 string containing the declared datatype

+**           of the table column that appears as the Nth column (numbered

+**           from 0) of the result set to the [prepared statement] S.

+**

+** {H13762}  A successful call to [sqlite3_column_decltype16(S,N)]

+**           returns a zero-terminated UTF-16 native byte order string

+**           containing the declared datatype of the table column that appears

+**           as the Nth column (numbered from 0) of the result set to the

+**           [prepared statement] S.

+**

+** {H13763}  If N is less than 0 or N is greater than or equal to

+**           the number of columns in the [prepared statement] S,

+**           or if the Nth column of S is an expression or subquery rather

+**           than a table column, or if a memory allocation failure

+**           occurs during encoding conversions, then

+**           calls to [sqlite3_column_decltype(S,N)] or

+**           [sqlite3_column_decltype16(S,N)] return NULL.

+*/

+const char *sqlite3_column_decltype(sqlite3_stmt*,int);

+const void *sqlite3_column_decltype16(sqlite3_stmt*,int);

+

+/*

+** CAPI3REF: Evaluate An SQL Statement {H13200} <S10000>

+**

+** After a [prepared statement] has been prepared using either

+** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy

+** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function

+** must be called one or more times to evaluate the statement.

+**

+** The details of the behavior of the sqlite3_step() interface depend

+** on whether the statement was prepared using the newer "v2" interface

+** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy

+** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the

+** new "v2" interface is recommended for new applications but the legacy

+** interface will continue to be supported.

+**

+** In the legacy interface, the return value will be either [SQLITE_BUSY],

+** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].

+** With the "v2" interface, any of the other [result codes] or

+** [extended result codes] might be returned as well.

+**

+** [SQLITE_BUSY] means that the database engine was unable to acquire the

+** database locks it needs to do its job.  If the statement is a [COMMIT]

+** or occurs outside of an explicit transaction, then you can retry the

+** statement.  If the statement is not a [COMMIT] and occurs within a

+** explicit transaction then you should rollback the transaction before

+** continuing.

+**

+** [SQLITE_DONE] means that the statement has finished executing

+** successfully.  sqlite3_step() should not be called again on this virtual

+** machine without first calling [sqlite3_reset()] to reset the virtual

+** machine back to its initial state.

+**

+** If the SQL statement being executed returns any data, then [SQLITE_ROW]

+** is returned each time a new row of data is ready for processing by the

+** caller. The values may be accessed using the [column access functions].

+** sqlite3_step() is called again to retrieve the next row of data.

+**

+** [SQLITE_ERROR] means that a run-time error (such as a constraint

+** violation) has occurred.  sqlite3_step() should not be called again on

+** the VM. More information may be found by calling [sqlite3_errmsg()].

+** With the legacy interface, a more specific error code (for example,

+** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)

+** can be obtained by calling [sqlite3_reset()] on the

+** [prepared statement].  In the "v2" interface,

+** the more specific error code is returned directly by sqlite3_step().

+**

+** [SQLITE_MISUSE] means that the this routine was called inappropriately.

+** Perhaps it was called on a [prepared statement] that has

+** already been [sqlite3_finalize | finalized] or on one that had

+** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could

+** be the case that the same database connection is being used by two or

+** more threads at the same moment in time.

+**

+** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()

+** API always returns a generic error code, [SQLITE_ERROR], following any

+** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call

+** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the

+** specific [error codes] that better describes the error.

+** We admit that this is a goofy design.  The problem has been fixed

+** with the "v2" interface.  If you prepare all of your SQL statements

+** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead

+** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,

+** then the more specific [error codes] are returned directly

+** by sqlite3_step().  The use of the "v2" interface is recommended.

+**

+** INVARIANTS:

+**

+** {H13202}  If the [prepared statement] S is ready to be run, then

+**           [sqlite3_step(S)] advances that prepared statement until

+**           completion or until it is ready to return another row of the

+**           result set, or until an [sqlite3_interrupt | interrupt]

+**           or a run-time error occurs.

+**

+** {H15304}  When a call to [sqlite3_step(S)] causes the [prepared statement]

+**           S to run to completion, the function returns [SQLITE_DONE].

+**

+** {H15306}  When a call to [sqlite3_step(S)] stops because it is ready to

+**           return another row of the result set, it returns [SQLITE_ROW].

+**

+** {H15308}  If a call to [sqlite3_step(S)] encounters an

+**           [sqlite3_interrupt | interrupt] or a run-time error,

+**           it returns an appropriate error code that is not one of

+**           [SQLITE_OK], [SQLITE_ROW], or [SQLITE_DONE].

+**

+** {H15310}  If an [sqlite3_interrupt | interrupt] or a run-time error

+**           occurs during a call to [sqlite3_step(S)]

+**           for a [prepared statement] S created using

+**           legacy interfaces [sqlite3_prepare()] or

+**           [sqlite3_prepare16()], then the function returns either

+**           [SQLITE_ERROR], [SQLITE_BUSY], or [SQLITE_MISUSE].

+*/

+int sqlite3_step(sqlite3_stmt*);

+

+/*

+** CAPI3REF: Number of columns in a result set {H13770} <S10700>

+**

+** Returns the number of values in the current row of the result set.

+**

+** INVARIANTS:

+**

+** {H13771}  After a call to [sqlite3_step(S)] that returns [SQLITE_ROW],

+**           the [sqlite3_data_count(S)] routine will return the same value

+**           as the [sqlite3_column_count(S)] function.

+**

+** {H13772}  After [sqlite3_step(S)] has returned any value other than

+**           [SQLITE_ROW] or before [sqlite3_step(S)] has been called on the

+**           [prepared statement] for the first time since it was

+**           [sqlite3_prepare | prepared] or [sqlite3_reset | reset],

+**           the [sqlite3_data_count(S)] routine returns zero.

+*/

+int sqlite3_data_count(sqlite3_stmt *pStmt);

+

+/*

+** CAPI3REF: Fundamental Datatypes {H10265} <S10110><S10120>

+** KEYWORDS: SQLITE_TEXT

+**

+** {H10266} Every value in SQLite has one of five fundamental datatypes:

+**

+** <ul>

+** <li> 64-bit signed integer

+** <li> 64-bit IEEE floating point number

+** <li> string

+** <li> BLOB

+** <li> NULL

+** </ul> {END}

+**

+** These constants are codes for each of those types.

+**

+** Note that the SQLITE_TEXT constant was also used in SQLite version 2

+** for a completely different meaning.  Software that links against both

+** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not

+** SQLITE_TEXT.

+*/

+#define SQLITE_INTEGER  1

+#define SQLITE_FLOAT    2

+#define SQLITE_BLOB     4

+#define SQLITE_NULL     5

+#ifdef SQLITE_TEXT

+# undef SQLITE_TEXT

+#else

+# define SQLITE_TEXT     3

+#endif

+#define SQLITE3_TEXT     3

+

+/*

+** CAPI3REF: Result Values From A Query {H13800} <S10700>

+** KEYWORDS: {column access functions}

+**

+** These routines form the "result set query" interface.

+**

+** These routines return information about a single column of the current

+** result row of a query.  In every case the first argument is a pointer

+** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]

+** that was returned from [sqlite3_prepare_v2()] or one of its variants)

+** and the second argument is the index of the column for which information

+** should be returned.  The leftmost column of the result set has the index 0.

+**

+** If the SQL statement does not currently point to a valid row, or if the

+** column index is out of range, the result is undefined.

+** These routines may only be called when the most recent call to

+** [sqlite3_step()] has returned [SQLITE_ROW] and neither

+** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.

+** If any of these routines are called after [sqlite3_reset()] or

+** [sqlite3_finalize()] or after [sqlite3_step()] has returned

+** something other than [SQLITE_ROW], the results are undefined.

+** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]

+** are called from a different thread while any of these routines

+** are pending, then the results are undefined.

+**

+** The sqlite3_column_type() routine returns the

+** [SQLITE_INTEGER | datatype code] for the initial data type

+** of the result column.  The returned value is one of [SQLITE_INTEGER],

+** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value

+** returned by sqlite3_column_type() is only meaningful if no type

+** conversions have occurred as described below.  After a type conversion,

+** the value returned by sqlite3_column_type() is undefined.  Future

+** versions of SQLite may change the behavior of sqlite3_column_type()

+** following a type conversion.

+**

+** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()

+** routine returns the number of bytes in that BLOB or string.

+** If the result is a UTF-16 string, then sqlite3_column_bytes() converts

+** the string to UTF-8 and then returns the number of bytes.

+** If the result is a numeric value then sqlite3_column_bytes() uses

+** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns

+** the number of bytes in that string.

+** The value returned does not include the zero terminator at the end

+** of the string.  For clarity: the value returned is the number of

+** bytes in the string, not the number of characters.

+**

+** Strings returned by sqlite3_column_text() and sqlite3_column_text16(),

+** even empty strings, are always zero terminated.  The return

+** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary

+** pointer, possibly even a NULL pointer.

+**

+** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()

+** but leaves the result in UTF-16 in native byte order instead of UTF-8.

+** The zero terminator is not included in this count.

+**

+** The object returned by [sqlite3_column_value()] is an

+** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object

+** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].

+** If the [unprotected sqlite3_value] object returned by

+** [sqlite3_column_value()] is used in any other way, including calls

+** to routines like [sqlite3_value_int()], [sqlite3_value_text()],

+** or [sqlite3_value_bytes()], then the behavior is undefined.

+**

+** These routines attempt to convert the value where appropriate.  For

+** example, if the internal representation is FLOAT and a text result

+** is requested, [sqlite3_snprintf()] is used internally to perform the

+** conversion automatically.  The following table details the conversions

+** that are applied:

+**

+** <blockquote>

+** <table border="1">

+** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion

+**

+** <tr><td>  NULL    <td> INTEGER   <td> Result is 0

+** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0

+** <tr><td>  NULL    <td>   TEXT    <td> Result is NULL pointer

+** <tr><td>  NULL    <td>   BLOB    <td> Result is NULL pointer

+** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float

+** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer

+** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT

+** <tr><td>  FLOAT   <td> INTEGER   <td> Convert from float to integer

+** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float

+** <tr><td>  FLOAT   <td>   BLOB    <td> Same as FLOAT->TEXT

+** <tr><td>  TEXT    <td> INTEGER   <td> Use atoi()

+** <tr><td>  TEXT    <td>  FLOAT    <td> Use atof()

+** <tr><td>  TEXT    <td>   BLOB    <td> No change

+** <tr><td>  BLOB    <td> INTEGER   <td> Convert to TEXT then use atoi()

+** <tr><td>  BLOB    <td>  FLOAT    <td> Convert to TEXT then use atof()

+** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed

+** </table>

+** </blockquote>

+**

+** The table above makes reference to standard C library functions atoi()

+** and atof().  SQLite does not really use these functions.  It has its

+** own equivalent internal routines.  The atoi() and atof() names are

+** used in the table for brevity and because they are familiar to most

+** C programmers.

+**

+** Note that when type conversions occur, pointers returned by prior

+** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or

+** sqlite3_column_text16() may be invalidated.

+** Type conversions and pointer invalidations might occur

+** in the following cases:

+**

+** <ul>

+** <li> The initial content is a BLOB and sqlite3_column_text() or

+**      sqlite3_column_text16() is called.  A zero-terminator might

+**      need to be added to the string.</li>

+** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or

+**      sqlite3_column_text16() is called.  The content must be converted

+**      to UTF-16.</li>

+** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or

+**      sqlite3_column_text() is called.  The content must be converted

+**      to UTF-8.</li>

+** </ul>

+**

+** Conversions between UTF-16be and UTF-16le are always done in place and do

+** not invalidate a prior pointer, though of course the content of the buffer

+** that the prior pointer points to will have been modified.  Other kinds

+** of conversion are done in place when it is possible, but sometimes they

+** are not possible and in those cases prior pointers are invalidated.

+**

+** The safest and easiest to remember policy is to invoke these routines

+** in one of the following ways:

+**

+** <ul>

+**  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>

+**  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>

+**  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>

+** </ul>

+**

+** In other words, you should call sqlite3_column_text(),

+** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result

+** into the desired format, then invoke sqlite3_column_bytes() or

+** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls

+** to sqlite3_column_text() or sqlite3_column_blob() with calls to

+** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()

+** with calls to sqlite3_column_bytes().

+**

+** The pointers returned are valid until a type conversion occurs as

+** described above, or until [sqlite3_step()] or [sqlite3_reset()] or

+** [sqlite3_finalize()] is called.  The memory space used to hold strings

+** and BLOBs is freed automatically.  Do <b>not</b> pass the pointers returned

+** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into

+** [sqlite3_free()].

+**

+** If a memory allocation error occurs during the evaluation of any

+** of these routines, a default value is returned.  The default value

+** is either the integer 0, the floating point number 0.0, or a NULL

+** pointer.  Subsequent calls to [sqlite3_errcode()] will return

+** [SQLITE_NOMEM].

+**

+** INVARIANTS:

+**

+** {H13803} The [sqlite3_column_blob(S,N)] interface converts the

+**          Nth column in the current row of the result set for

+**          the [prepared statement] S into a BLOB and then returns a

+**          pointer to the converted value.

+**

+** {H13806} The [sqlite3_column_bytes(S,N)] interface returns the

+**          number of bytes in the BLOB or string (exclusive of the

+**          zero terminator on the string) that was returned by the

+**          most recent call to [sqlite3_column_blob(S,N)] or

+**          [sqlite3_column_text(S,N)].

+**

+** {H13809} The [sqlite3_column_bytes16(S,N)] interface returns the

+**          number of bytes in the string (exclusive of the

+**          zero terminator on the string) that was returned by the

+**          most recent call to [sqlite3_column_text16(S,N)].

+**

+** {H13812} The [sqlite3_column_double(S,N)] interface converts the

+**          Nth column in the current row of the result set for the

+**          [prepared statement] S into a floating point value and

+**          returns a copy of that value.

+**

+** {H13815} The [sqlite3_column_int(S,N)] interface converts the

+**          Nth column in the current row of the result set for the

+**          [prepared statement] S into a 64-bit signed integer and

+**          returns the lower 32 bits of that integer.

+**

+** {H13818} The [sqlite3_column_int64(S,N)] interface converts the

+**          Nth column in the current row of the result set for the

+**          [prepared statement] S into a 64-bit signed integer and

+**          returns a copy of that integer.

+**

+** {H13821} The [sqlite3_column_text(S,N)] interface converts the

+**          Nth column in the current row of the result set for

+**          the [prepared statement] S into a zero-terminated UTF-8

+**          string and returns a pointer to that string.

+**

+** {H13824} The [sqlite3_column_text16(S,N)] interface converts the

+**          Nth column in the current row of the result set for the

+**          [prepared statement] S into a zero-terminated 2-byte

+**          aligned UTF-16 native byte order string and returns

+**          a pointer to that string.

+**

+** {H13827} The [sqlite3_column_type(S,N)] interface returns

+**          one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT],

+**          [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for

+**          the Nth column in the current row of the result set for

+**          the [prepared statement] S.

+**

+** {H13830} The [sqlite3_column_value(S,N)] interface returns a

+**          pointer to an [unprotected sqlite3_value] object for the

+**          Nth column in the current row of the result set for

+**          the [prepared statement] S.

+*/

+const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);

+int sqlite3_column_bytes(sqlite3_stmt*, int iCol);

+int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);

+double sqlite3_column_double(sqlite3_stmt*, int iCol);

+int sqlite3_column_int(sqlite3_stmt*, int iCol);

+sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);

+const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);

+const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);

+int sqlite3_column_type(sqlite3_stmt*, int iCol);

+sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);

+

+/*

+** CAPI3REF: Destroy A Prepared Statement Object {H13300} <S70300><S30100>

+**

+** The sqlite3_finalize() function is called to delete a [prepared statement].

+** If the statement was executed successfully or not executed at all, then

+** SQLITE_OK is returned. If execution of the statement failed then an

+** [error code] or [extended error code] is returned.

+**

+** This routine can be called at any point during the execution of the

+** [prepared statement].  If the virtual machine has not

+** completed execution when this routine is called, that is like

+** encountering an error or an [sqlite3_interrupt | interrupt].

+** Incomplete updates may be rolled back and transactions canceled,

+** depending on the circumstances, and the

+** [error code] returned will be [SQLITE_ABORT].

+**

+** INVARIANTS:

+**

+** {H11302} The [sqlite3_finalize(S)] interface destroys the

+**          [prepared statement] S and releases all

+**          memory and file resources held by that object.

+**

+** {H11304} If the most recent call to [sqlite3_step(S)] for the

+**          [prepared statement] S returned an error,

+**          then [sqlite3_finalize(S)] returns that same error.

+*/

+int sqlite3_finalize(sqlite3_stmt *pStmt);

+

+/*

+** CAPI3REF: Reset A Prepared Statement Object {H13330} <S70300>

+**

+** The sqlite3_reset() function is called to reset a [prepared statement]

+** object back to its initial state, ready to be re-executed.

+** Any SQL statement variables that had values bound to them using

+** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.

+** Use [sqlite3_clear_bindings()] to reset the bindings.

+**

+** {H11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S

+**          back to the beginning of its program.

+**

+** {H11334} If the most recent call to [sqlite3_step(S)] for the

+**          [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],

+**          or if [sqlite3_step(S)] has never before been called on S,

+**          then [sqlite3_reset(S)] returns [SQLITE_OK].

+**

+** {H11336} If the most recent call to [sqlite3_step(S)] for the

+**          [prepared statement] S indicated an error, then

+**          [sqlite3_reset(S)] returns an appropriate [error code].

+**

+** {H11338} The [sqlite3_reset(S)] interface does not change the values

+**          of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.

+*/

+int sqlite3_reset(sqlite3_stmt *pStmt);

+

+/*

+** CAPI3REF: Create Or Redefine SQL Functions {H16100} <S20200>

+** KEYWORDS: {function creation routines}

+** KEYWORDS: {application-defined SQL function}

+** KEYWORDS: {application-defined SQL functions}

+**

+** These two functions (collectively known as "function creation routines")

+** are used to add SQL functions or aggregates or to redefine the behavior

+** of existing SQL functions or aggregates.  The only difference between the

+** two is that the second parameter, the name of the (scalar) function or

+** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16

+** for sqlite3_create_function16().

+**

+** The first parameter is the [database connection] to which the SQL

+** function is to be added.  If a single program uses more than one database

+** connection internally, then SQL functions must be added individually to

+** each database connection.

+**

+** The second parameter is the name of the SQL function to be created or

+** redefined.  The length of the name is limited to 255 bytes, exclusive of

+** the zero-terminator.  Note that the name length limit is in bytes, not

+** characters.  Any attempt to create a function with a longer name

+** will result in [SQLITE_ERROR] being returned.

+**

+** The third parameter is the number of arguments that the SQL function or

+** aggregate takes. If this parameter is negative, then the SQL function or

+** aggregate may take any number of arguments.

+**

+** The fourth parameter, eTextRep, specifies what

+** [SQLITE_UTF8 | text encoding] this SQL function prefers for

+** its parameters.  Any SQL function implementation should be able to work

+** work with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be

+** more efficient with one encoding than another.  It is allowed to

+** invoke sqlite3_create_function() or sqlite3_create_function16() multiple

+** times with the same function but with different values of eTextRep.

+** When multiple implementations of the same function are available, SQLite

+** will pick the one that involves the least amount of data conversion.

+** If there is only a single implementation which does not care what text

+** encoding is used, then the fourth argument should be [SQLITE_ANY].

+**

+** The fifth parameter is an arbitrary pointer.  The implementation of the

+** function can gain access to this pointer using [sqlite3_user_data()].

+**

+** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are

+** pointers to C-language functions that implement the SQL function or

+** aggregate. A scalar SQL function requires an implementation of the xFunc

+** callback only, NULL pointers should be passed as the xStep and xFinal

+** parameters. An aggregate SQL function requires an implementation of xStep

+** and xFinal and NULL should be passed for xFunc. To delete an existing

+** SQL function or aggregate, pass NULL for all three function callbacks.

+**

+** It is permitted to register multiple implementations of the same

+** functions with the same name but with either differing numbers of

+** arguments or differing preferred text encodings.  SQLite will use

+** the implementation most closely matches the way in which the

+** SQL function is used.

+**

+** INVARIANTS:

+**

+** {H16103} The [sqlite3_create_function16()] interface behaves exactly

+**          like [sqlite3_create_function()] in every way except that it

+**          interprets the zFunctionName argument as zero-terminated UTF-16

+**          native byte order instead of as zero-terminated UTF-8.

+**

+** {H16106} A successful invocation of

+**          the [sqlite3_create_function(D,X,N,E,...)] interface registers

+**          or replaces callback functions in the [database connection] D

+**          used to implement the SQL function named X with N parameters

+**          and having a preferred text encoding of E.

+**

+** {H16109} A successful call to [sqlite3_create_function(D,X,N,E,P,F,S,L)]

+**          replaces the P, F, S, and L values from any prior calls with

+**          the same D, X, N, and E values.

+**

+** {H16112} The [sqlite3_create_function(D,X,...)] interface fails with

+**          a return code of [SQLITE_ERROR] if the SQL function name X is

+**          longer than 255 bytes exclusive of the zero terminator.

+**

+** {H16118} Either F must be NULL and S and L are non-NULL or else F

+**          is non-NULL and S and L are NULL, otherwise

+**          [sqlite3_create_function(D,X,N,E,P,F,S,L)] returns [SQLITE_ERROR].

+**

+** {H16121} The [sqlite3_create_function(D,...)] interface fails with an

+**          error code of [SQLITE_BUSY] if there exist [prepared statements]

+**          associated with the [database connection] D.

+**

+** {H16124} The [sqlite3_create_function(D,X,N,...)] interface fails with an

+**          error code of [SQLITE_ERROR] if parameter N (specifying the number

+**          of arguments to the SQL function being registered) is less

+**          than -1 or greater than 127.

+**

+** {H16127} When N is non-negative, the [sqlite3_create_function(D,X,N,...)]

+**          interface causes callbacks to be invoked for the SQL function

+**          named X when the number of arguments to the SQL function is

+**          exactly N.

+**

+** {H16130} When N is -1, the [sqlite3_create_function(D,X,N,...)]

+**          interface causes callbacks to be invoked for the SQL function

+**          named X with any number of arguments.

+**

+** {H16133} When calls to [sqlite3_create_function(D,X,N,...)]

+**          specify multiple implementations of the same function X

+**          and when one implementation has N>=0 and the other has N=(-1)

+**          the implementation with a non-zero N is preferred.

+**

+** {H16136} When calls to [sqlite3_create_function(D,X,N,E,...)]

+**          specify multiple implementations of the same function X with

+**          the same number of arguments N but with different

+**          encodings E, then the implementation where E matches the

+**          database encoding is preferred.

+**

+** {H16139} For an aggregate SQL function created using

+**          [sqlite3_create_function(D,X,N,E,P,0,S,L)] the finalizer

+**          function L will always be invoked exactly once if the

+**          step function S is called one or more times.

+**

+** {H16142} When SQLite invokes either the xFunc or xStep function of

+**          an application-defined SQL function or aggregate created

+**          by [sqlite3_create_function()] or [sqlite3_create_function16()],

+**          then the array of [sqlite3_value] objects passed as the

+**          third parameter are always [protected sqlite3_value] objects.

+*/

+int sqlite3_create_function(

+  sqlite3 *db,

+  const char *zFunctionName,

+  int nArg,

+  int eTextRep,

+  void *pApp,

+  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),

+  void (*xStep)(sqlite3_context*,int,sqlite3_value**),

+  void (*xFinal)(sqlite3_context*)

+);

+int sqlite3_create_function16(

+  sqlite3 *db,

+  const void *zFunctionName,

+  int nArg,

+  int eTextRep,

+  void *pApp,

+  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),

+  void (*xStep)(sqlite3_context*,int,sqlite3_value**),

+  void (*xFinal)(sqlite3_context*)

+);

+

+/*

+** CAPI3REF: Text Encodings {H10267} <S50200> <H16100>

+**

+** These constant define integer codes that represent the various

+** text encodings supported by SQLite.

+*/

+#define SQLITE_UTF8           1

+#define SQLITE_UTF16LE        2

+#define SQLITE_UTF16BE        3

+#define SQLITE_UTF16          4    /* Use native byte order */

+#define SQLITE_ANY            5    /* sqlite3_create_function only */

+#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */

+

+/*

+** CAPI3REF: Deprecated Functions

+** DEPRECATED

+**

+** These functions are [deprecated].  In order to maintain

+** backwards compatibility with older code, these functions continue 

+** to be supported.  However, new applications should avoid

+** the use of these functions.  To help encourage people to avoid

+** using these functions, we are not going to tell you want they do.

+*/

+int sqlite3_aggregate_count(sqlite3_context*);

+int sqlite3_expired(sqlite3_stmt*);

+int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);

+int sqlite3_global_recover(void);

+void sqlite3_thread_cleanup(void);

+int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);

+

+/*

+** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} <S20200>

+**

+** The C-language implementation of SQL functions and aggregates uses

+** this set of interface routines to access the parameter values on

+** the function or aggregate.

+**

+** The xFunc (for scalar functions) or xStep (for aggregates) parameters

+** to [sqlite3_create_function()] and [sqlite3_create_function16()]

+** define callbacks that implement the SQL functions and aggregates.

+** The 4th parameter to these callbacks is an array of pointers to

+** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for

+** each parameter to the SQL function.  These routines are used to

+** extract values from the [sqlite3_value] objects.

+**

+** These routines work only with [protected sqlite3_value] objects.

+** Any attempt to use these routines on an [unprotected sqlite3_value]

+** object results in undefined behavior.

+**

+** These routines work just like the corresponding [column access functions]

+** except that  these routines take a single [protected sqlite3_value] object

+** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.

+**

+** The sqlite3_value_text16() interface extracts a UTF-16 string

+** in the native byte-order of the host machine.  The

+** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces

+** extract UTF-16 strings as big-endian and little-endian respectively.

+**

+** The sqlite3_value_numeric_type() interface attempts to apply

+** numeric affinity to the value.  This means that an attempt is

+** made to convert the value to an integer or floating point.  If

+** such a conversion is possible without loss of information (in other

+** words, if the value is a string that looks like a number)

+** then the conversion is performed.  Otherwise no conversion occurs.

+** The [SQLITE_INTEGER | datatype] after conversion is returned.

+**

+** Please pay particular attention to the fact that the pointer returned

+** from [sqlite3_value_blob()], [sqlite3_value_text()], or

+** [sqlite3_value_text16()] can be invalidated by a subsequent call to

+** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],

+** or [sqlite3_value_text16()].

+**

+** These routines must be called from the same thread as

+** the SQL function that supplied the [sqlite3_value*] parameters.

+**

+** INVARIANTS:

+**

+** {H15103} The [sqlite3_value_blob(V)] interface converts the

+**          [protected sqlite3_value] object V into a BLOB and then

+**          returns a pointer to the converted value.

+**

+** {H15106} The [sqlite3_value_bytes(V)] interface returns the

+**          number of bytes in the BLOB or string (exclusive of the

+**          zero terminator on the string) that was returned by the

+**          most recent call to [sqlite3_value_blob(V)] or

+**          [sqlite3_value_text(V)].

+**

+** {H15109} The [sqlite3_value_bytes16(V)] interface returns the

+**          number of bytes in the string (exclusive of the

+**          zero terminator on the string) that was returned by the

+**          most recent call to [sqlite3_value_text16(V)],

+**          [sqlite3_value_text16be(V)], or [sqlite3_value_text16le(V)].

+**

+** {H15112} The [sqlite3_value_double(V)] interface converts the

+**          [protected sqlite3_value] object V into a floating point value and

+**          returns a copy of that value.

+**

+** {H15115} The [sqlite3_value_int(V)] interface converts the

+**          [protected sqlite3_value] object V into a 64-bit signed integer and

+**          returns the lower 32 bits of that integer.

+**

+** {H15118} The [sqlite3_value_int64(V)] interface converts the

+**          [protected sqlite3_value] object V into a 64-bit signed integer and

+**          returns a copy of that integer.

+**

+** {H15121} The [sqlite3_value_text(V)] interface converts the

+**          [protected sqlite3_value] object V into a zero-terminated UTF-8

+**          string and returns a pointer to that string.

+**

+** {H15124} The [sqlite3_value_text16(V)] interface converts the

+**          [protected sqlite3_value] object V into a zero-terminated 2-byte

+**          aligned UTF-16 native byte order

+**          string and returns a pointer to that string.

+**

+** {H15127} The [sqlite3_value_text16be(V)] interface converts the

+**          [protected sqlite3_value] object V into a zero-terminated 2-byte

+**          aligned UTF-16 big-endian

+**          string and returns a pointer to that string.

+**

+** {H15130} The [sqlite3_value_text16le(V)] interface converts the

+**          [protected sqlite3_value] object V into a zero-terminated 2-byte

+**          aligned UTF-16 little-endian

+**          string and returns a pointer to that string.

+**

+** {H15133} The [sqlite3_value_type(V)] interface returns

+**          one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT],

+**          [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for

+**          the [sqlite3_value] object V.

+**

+** {H15136} The [sqlite3_value_numeric_type(V)] interface converts

+**          the [protected sqlite3_value] object V into either an integer or

+**          a floating point value if it can do so without loss of

+**          information, and returns one of [SQLITE_NULL],

+**          [SQLITE_INTEGER], [SQLITE_FLOAT], [SQLITE_TEXT], or

+**          [SQLITE_BLOB] as appropriate for the

+**          [protected sqlite3_value] object V after the conversion attempt.

+*/

+const void *sqlite3_value_blob(sqlite3_value*);

+int sqlite3_value_bytes(sqlite3_value*);

+int sqlite3_value_bytes16(sqlite3_value*);

+double sqlite3_value_double(sqlite3_value*);

+int sqlite3_value_int(sqlite3_value*);

+sqlite3_int64 sqlite3_value_int64(sqlite3_value*);

+const unsigned char *sqlite3_value_text(sqlite3_value*);

+const void *sqlite3_value_text16(sqlite3_value*);

+const void *sqlite3_value_text16le(sqlite3_value*);

+const void *sqlite3_value_text16be(sqlite3_value*);

+int sqlite3_value_type(sqlite3_value*);

+int sqlite3_value_numeric_type(sqlite3_value*);

+

+/*

+** CAPI3REF: Obtain Aggregate Function Context {H16210} <S20200>

+**

+** The implementation of aggregate SQL functions use this routine to allocate

+** a structure for storing their state.

+**

+** The first time the sqlite3_aggregate_context() routine is called for a

+** particular aggregate, SQLite allocates nBytes of memory, zeroes out that

+** memory, and returns a pointer to it. On second and subsequent calls to

+** sqlite3_aggregate_context() for the same aggregate function index,

+** the same buffer is returned. The implementation of the aggregate can use

+** the returned buffer to accumulate data.

+**

+** SQLite automatically frees the allocated buffer when the aggregate

+** query concludes.

+**

+** The first parameter should be a copy of the

+** [sqlite3_context | SQL function context] that is the first parameter

+** to the callback routine that implements the aggregate function.

+**

+** This routine must be called from the same thread in which

+** the aggregate SQL function is running.

+**

+** INVARIANTS:

+**

+** {H16211} The first invocation of [sqlite3_aggregate_context(C,N)] for

+**          a particular instance of an aggregate function (for a particular

+**          context C) causes SQLite to allocate N bytes of memory,

+**          zero that memory, and return a pointer to the allocated memory.

+**

+** {H16213} If a memory allocation error occurs during

+**          [sqlite3_aggregate_context(C,N)] then the function returns 0.

+**

+** {H16215} Second and subsequent invocations of

+**          [sqlite3_aggregate_context(C,N)] for the same context pointer C

+**          ignore the N parameter and return a pointer to the same

+**          block of memory returned by the first invocation.

+**

+** {H16217} The memory allocated by [sqlite3_aggregate_context(C,N)] is

+**          automatically freed on the next call to [sqlite3_reset()]

+**          or [sqlite3_finalize()] for the [prepared statement] containing

+**          the aggregate function associated with context C.

+*/

+void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);

+

+/*

+** CAPI3REF: User Data For Functions {H16240} <S20200>

+**

+** The sqlite3_user_data() interface returns a copy of

+** the pointer that was the pUserData parameter (the 5th parameter)

+** of the [sqlite3_create_function()]

+** and [sqlite3_create_function16()] routines that originally

+** registered the application defined function. {END}

+**

+** This routine must be called from the same thread in which

+** the application-defined function is running.

+**

+** INVARIANTS:

+**

+** {H16243} The [sqlite3_user_data(C)] interface returns a copy of the

+**          P pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)]

+**          or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that

+**          registered the SQL function associated with [sqlite3_context] C.

+*/

+void *sqlite3_user_data(sqlite3_context*);

+

+/*

+** CAPI3REF: Database Connection For Functions {H16250} <S60600><S20200>

+**

+** The sqlite3_context_db_handle() interface returns a copy of

+** the pointer to the [database connection] (the 1st parameter)

+** of the [sqlite3_create_function()]

+** and [sqlite3_create_function16()] routines that originally

+** registered the application defined function.

+**

+** INVARIANTS:

+**

+** {H16253} The [sqlite3_context_db_handle(C)] interface returns a copy of the

+**          D pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)]

+**          or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that

+**          registered the SQL function associated with [sqlite3_context] C.

+*/

+sqlite3 *sqlite3_context_db_handle(sqlite3_context*);

+

+/*

+** CAPI3REF: Function Auxiliary Data {H16270} <S20200>

+**

+** The following two functions may be used by scalar SQL functions to

+** associate metadata with argument values. If the same value is passed to

+** multiple invocations of the same SQL function during query execution, under

+** some circumstances the associated metadata may be preserved. This may

+** be used, for example, to add a regular-expression matching scalar

+** function. The compiled version of the regular expression is stored as

+** metadata associated with the SQL value passed as the regular expression

+** pattern.  The compiled regular expression can be reused on multiple

+** invocations of the same function so that the original pattern string

+** does not need to be recompiled on each invocation.

+**

+** The sqlite3_get_auxdata() interface returns a pointer to the metadata

+** associated by the sqlite3_set_auxdata() function with the Nth argument

+** value to the application-defined function. If no metadata has been ever

+** been set for the Nth argument of the function, or if the corresponding

+** function parameter has changed since the meta-data was set,

+** then sqlite3_get_auxdata() returns a NULL pointer.

+**

+** The sqlite3_set_auxdata() interface saves the metadata

+** pointed to by its 3rd parameter as the metadata for the N-th

+** argument of the application-defined function.  Subsequent

+** calls to sqlite3_get_auxdata() might return this data, if it has

+** not been destroyed.

+** If it is not NULL, SQLite will invoke the destructor

+** function given by the 4th parameter to sqlite3_set_auxdata() on

+** the metadata when the corresponding function parameter changes

+** or when the SQL statement completes, whichever comes first.

+**

+** SQLite is free to call the destructor and drop metadata on any

+** parameter of any function at any time.  The only guarantee is that

+** the destructor will be called before the metadata is dropped.

+**

+** In practice, metadata is preserved between function calls for

+** expressions that are constant at compile time. This includes literal

+** values and SQL variables.

+**

+** These routines must be called from the same thread in which

+** the SQL function is running.

+**

+** INVARIANTS:

+**

+** {H16272} The [sqlite3_get_auxdata(C,N)] interface returns a pointer

+**          to metadata associated with the Nth parameter of the SQL function

+**          whose context is C, or NULL if there is no metadata associated

+**          with that parameter.

+**

+** {H16274} The [sqlite3_set_auxdata(C,N,P,D)] interface assigns a metadata

+**          pointer P to the Nth parameter of the SQL function with context C.

+**

+** {H16276} SQLite will invoke the destructor D with a single argument

+**          which is the metadata pointer P following a call to

+**          [sqlite3_set_auxdata(C,N,P,D)] when SQLite ceases to hold

+**          the metadata.

+**

+** {H16277} SQLite ceases to hold metadata for an SQL function parameter

+**          when the value of that parameter changes.

+**

+** {H16278} When [sqlite3_set_auxdata(C,N,P,D)] is invoked, the destructor

+**          is called for any prior metadata associated with the same function

+**          context C and parameter N.

+**

+** {H16279} SQLite will call destructors for any metadata it is holding

+**          in a particular [prepared statement] S when either

+**          [sqlite3_reset(S)] or [sqlite3_finalize(S)] is called.

+*/

+void *sqlite3_get_auxdata(sqlite3_context*, int N);

+void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));

+

+

+/*

+** CAPI3REF: Constants Defining Special Destructor Behavior {H10280} <S30100>

+**

+** These are special values for the destructor that is passed in as the

+** final argument to routines like [sqlite3_result_blob()].  If the destructor

+** argument is SQLITE_STATIC, it means that the content pointer is constant

+** and will never change.  It does not need to be destroyed.  The

+** SQLITE_TRANSIENT value means that the content will likely change in

+** the near future and that SQLite should make its own private copy of

+** the content before returning.

+**

+** The typedef is necessary to work around problems in certain

+** C++ compilers.  See ticket #2191.

+*/

+typedef void (*sqlite3_destructor_type)(void*);

+#define SQLITE_STATIC      ((sqlite3_destructor_type)0)

+#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)

+

+/*

+** CAPI3REF: Setting The Result Of An SQL Function {H16400} <S20200>

+**

+** These routines are used by the xFunc or xFinal callbacks that

+** implement SQL functions and aggregates.  See

+** [sqlite3_create_function()] and [sqlite3_create_function16()]

+** for additional information.

+**

+** These functions work very much like the [parameter binding] family of

+** functions used to bind values to host parameters in prepared statements.

+** Refer to the [SQL parameter] documentation for additional information.

+**

+** The sqlite3_result_blob() interface sets the result from

+** an application-defined function to be the BLOB whose content is pointed

+** to by the second parameter and which is N bytes long where N is the

+** third parameter.

+**

+** The sqlite3_result_zeroblob() interfaces set the result of

+** the application-defined function to be a BLOB containing all zero

+** bytes and N bytes in size, where N is the value of the 2nd parameter.

+**

+** The sqlite3_result_double() interface sets the result from

+** an application-defined function to be a floating point value specified

+** by its 2nd argument.

+**

+** The sqlite3_result_error() and sqlite3_result_error16() functions

+** cause the implemented SQL function to throw an exception.

+** SQLite uses the string pointed to by the

+** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()

+** as the text of an error message.  SQLite interprets the error

+** message string from sqlite3_result_error() as UTF-8. SQLite

+** interprets the string from sqlite3_result_error16() as UTF-16 in native

+** byte order.  If the third parameter to sqlite3_result_error()

+** or sqlite3_result_error16() is negative then SQLite takes as the error

+** message all text up through the first zero character.

+** If the third parameter to sqlite3_result_error() or

+** sqlite3_result_error16() is non-negative then SQLite takes that many

+** bytes (not characters) from the 2nd parameter as the error message.

+** The sqlite3_result_error() and sqlite3_result_error16()

+** routines make a private copy of the error message text before

+** they return.  Hence, the calling function can deallocate or

+** modify the text after they return without harm.

+** The sqlite3_result_error_code() function changes the error code

+** returned by SQLite as a result of an error in a function.  By default,

+** the error code is SQLITE_ERROR.  A subsequent call to sqlite3_result_error()

+** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.

+**

+** The sqlite3_result_toobig() interface causes SQLite to throw an error

+** indicating that a string or BLOB is to long to represent.

+**

+** The sqlite3_result_nomem() interface causes SQLite to throw an error

+** indicating that a memory allocation failed.

+**

+** The sqlite3_result_int() interface sets the return value

+** of the application-defined function to be the 32-bit signed integer

+** value given in the 2nd argument.

+** The sqlite3_result_int64() interface sets the return value

+** of the application-defined function to be the 64-bit signed integer

+** value given in the 2nd argument.

+**

+** The sqlite3_result_null() interface sets the return value

+** of the application-defined function to be NULL.

+**

+** The sqlite3_result_text(), sqlite3_result_text16(),

+** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces

+** set the return value of the application-defined function to be

+** a text string which is represented as UTF-8, UTF-16 native byte order,

+** UTF-16 little endian, or UTF-16 big endian, respectively.

+** SQLite takes the text result from the application from

+** the 2nd parameter of the sqlite3_result_text* interfaces.

+** If the 3rd parameter to the sqlite3_result_text* interfaces

+** is negative, then SQLite takes result text from the 2nd parameter

+** through the first zero character.

+** If the 3rd parameter to the sqlite3_result_text* interfaces

+** is non-negative, then as many bytes (not characters) of the text

+** pointed to by the 2nd parameter are taken as the application-defined

+** function result.

+** If the 4th parameter to the sqlite3_result_text* interfaces

+** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that

+** function as the destructor on the text or BLOB result when it has

+** finished using that result.

+** If the 4th parameter to the sqlite3_result_text* interfaces or

+** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite

+** assumes that the text or BLOB result is in constant space and does not

+** copy the it or call a destructor when it has finished using that result.

+** If the 4th parameter to the sqlite3_result_text* interfaces

+** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT

+** then SQLite makes a copy of the result into space obtained from

+** from [sqlite3_malloc()] before it returns.

+**

+** The sqlite3_result_value() interface sets the result of

+** the application-defined function to be a copy the

+** [unprotected sqlite3_value] object specified by the 2nd parameter.  The

+** sqlite3_result_value() interface makes a copy of the [sqlite3_value]

+** so that the [sqlite3_value] specified in the parameter may change or

+** be deallocated after sqlite3_result_value() returns without harm.

+** A [protected sqlite3_value] object may always be used where an

+** [unprotected sqlite3_value] object is required, so either

+** kind of [sqlite3_value] object can be used with this interface.

+**

+** If these routines are called from within the different thread

+** than the one containing the application-defined function that received

+** the [sqlite3_context] pointer, the results are undefined.

+**

+** INVARIANTS:

+**

+** {H16403} The default return value from any SQL function is NULL.

+**

+** {H16406} The [sqlite3_result_blob(C,V,N,D)] interface changes the

+**          return value of function C to be a BLOB that is N bytes

+**          in length and with content pointed to by V.

+**

+** {H16409} The [sqlite3_result_double(C,V)] interface changes the

+**          return value of function C to be the floating point value V.

+**

+** {H16412} The [sqlite3_result_error(C,V,N)] interface changes the return

+**          value of function C to be an exception with error code

+**          [SQLITE_ERROR] and a UTF-8 error message copied from V up to the

+**          first zero byte or until N bytes are read if N is positive.

+**

+** {H16415} The [sqlite3_result_error16(C,V,N)] interface changes the return

+**          value of function C to be an exception with error code

+**          [SQLITE_ERROR] and a UTF-16 native byte order error message

+**          copied from V up to the first zero terminator or until N bytes

+**          are read if N is positive.

+**

+** {H16418} The [sqlite3_result_error_toobig(C)] interface changes the return

+**          value of the function C to be an exception with error code

+**          [SQLITE_TOOBIG] and an appropriate error message.

+**

+** {H16421} The [sqlite3_result_error_nomem(C)] interface changes the return

+**          value of the function C to be an exception with error code

+**          [SQLITE_NOMEM] and an appropriate error message.

+**

+** {H16424} The [sqlite3_result_error_code(C,E)] interface changes the return

+**          value of the function C to be an exception with error code E.

+**          The error message text is unchanged.

+**

+** {H16427} The [sqlite3_result_int(C,V)] interface changes the

+**          return value of function C to be the 32-bit integer value V.

+**

+** {H16430} The [sqlite3_result_int64(C,V)] interface changes the

+**          return value of function C to be the 64-bit integer value V.

+**

+** {H16433} The [sqlite3_result_null(C)] interface changes the

+**          return value of function C to be NULL.

+**

+** {H16436} The [sqlite3_result_text(C,V,N,D)] interface changes the

+**          return value of function C to be the UTF-8 string

+**          V up to the first zero if N is negative

+**          or the first N bytes of V if N is non-negative.

+**

+** {H16439} The [sqlite3_result_text16(C,V,N,D)] interface changes the

+**          return value of function C to be the UTF-16 native byte order

+**          string V up to the first zero if N is negative

+**          or the first N bytes of V if N is non-negative.

+**

+** {H16442} The [sqlite3_result_text16be(C,V,N,D)] interface changes the

+**          return value of function C to be the UTF-16 big-endian

+**          string V up to the first zero if N is negative

+**          or the first N bytes or V if N is non-negative.

+**

+** {H16445} The [sqlite3_result_text16le(C,V,N,D)] interface changes the

+**          return value of function C to be the UTF-16 little-endian

+**          string V up to the first zero if N is negative

+**          or the first N bytes of V if N is non-negative.

+**

+** {H16448} The [sqlite3_result_value(C,V)] interface changes the

+**          return value of function C to be the [unprotected sqlite3_value]

+**          object V.

+**

+** {H16451} The [sqlite3_result_zeroblob(C,N)] interface changes the

+**          return value of function C to be an N-byte BLOB of all zeros.

+**

+** {H16454} The [sqlite3_result_error()] and [sqlite3_result_error16()]

+**          interfaces make a copy of their error message strings before

+**          returning.

+**

+** {H16457} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],

+**          [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],

+**          [sqlite3_result_text16be(C,V,N,D)], or

+**          [sqlite3_result_text16le(C,V,N,D)] is the constant [SQLITE_STATIC]

+**          then no destructor is ever called on the pointer V and SQLite

+**          assumes that V is immutable.

+**

+** {H16460} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],

+**          [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],

+**          [sqlite3_result_text16be(C,V,N,D)], or

+**          [sqlite3_result_text16le(C,V,N,D)] is the constant

+**          [SQLITE_TRANSIENT] then the interfaces makes a copy of the

+**          content of V and retains the copy.

+**

+** {H16463} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],

+**          [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],

+**          [sqlite3_result_text16be(C,V,N,D)], or

+**          [sqlite3_result_text16le(C,V,N,D)] is some value other than

+**          the constants [SQLITE_STATIC] and [SQLITE_TRANSIENT] then

+**          SQLite will invoke the destructor D with V as its only argument

+**          when it has finished with the V value.

+*/

+void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));

+void sqlite3_result_double(sqlite3_context*, double);

+void sqlite3_result_error(sqlite3_context*, const char*, int);

+void sqlite3_result_error16(sqlite3_context*, const void*, int);

+void sqlite3_result_error_toobig(sqlite3_context*);

+void sqlite3_result_error_nomem(sqlite3_context*);

+void sqlite3_result_error_code(sqlite3_context*, int);

+void sqlite3_result_int(sqlite3_context*, int);

+void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);

+void sqlite3_result_null(sqlite3_context*);

+void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));

+void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));

+void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));

+void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));

+void sqlite3_result_value(sqlite3_context*, sqlite3_value*);

+void sqlite3_result_zeroblob(sqlite3_context*, int n);

+

+/*

+** CAPI3REF: Define New Collating Sequences {H16600} <S20300>

+**

+** These functions are used to add new collation sequences to the

+** [database connection] specified as the first argument.

+**

+** The name of the new collation sequence is specified as a UTF-8 string

+** for sqlite3_create_collation() and sqlite3_create_collation_v2()

+** and a UTF-16 string for sqlite3_create_collation16(). In all cases

+** the name is passed as the second function argument.

+**

+** The third argument may be one of the constants [SQLITE_UTF8],

+** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied

+** routine expects to be passed pointers to strings encoded using UTF-8,

+** UTF-16 little-endian, or UTF-16 big-endian, respectively. The

+** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that

+** the routine expects pointers to 16-bit word aligned strings

+** of UTF-16 in the native byte order of the host computer.

+**

+** A pointer to the user supplied routine must be passed as the fifth

+** argument.  If it is NULL, this is the same as deleting the collation

+** sequence (so that SQLite cannot call it anymore).

+** Each time the application supplied function is invoked, it is passed

+** as its first parameter a copy of the void* passed as the fourth argument

+** to sqlite3_create_collation() or sqlite3_create_collation16().

+**

+** The remaining arguments to the application-supplied routine are two strings,

+** each represented by a (length, data) pair and encoded in the encoding

+** that was passed as the third argument when the collation sequence was

+** registered. {END}  The application defined collation routine should

+** return negative, zero or positive if the first string is less than,

+** equal to, or greater than the second string. i.e. (STRING1 - STRING2).

+**

+** The sqlite3_create_collation_v2() works like sqlite3_create_collation()

+** except that it takes an extra argument which is a destructor for

+** the collation.  The destructor is called when the collation is

+** destroyed and is passed a copy of the fourth parameter void* pointer

+** of the sqlite3_create_collation_v2().

+** Collations are destroyed when they are overridden by later calls to the

+** collation creation functions or when the [database connection] is closed

+** using [sqlite3_close()].

+**

+** INVARIANTS:

+**

+** {H16603} A successful call to the

+**          [sqlite3_create_collation_v2(B,X,E,P,F,D)] interface

+**          registers function F as the comparison function used to

+**          implement collation X on the [database connection] B for

+**          databases having encoding E.

+**

+** {H16604} SQLite understands the X parameter to

+**          [sqlite3_create_collation_v2(B,X,E,P,F,D)] as a zero-terminated

+**          UTF-8 string in which case is ignored for ASCII characters and

+**          is significant for non-ASCII characters.

+**

+** {H16606} Successive calls to [sqlite3_create_collation_v2(B,X,E,P,F,D)]

+**          with the same values for B, X, and E, override prior values

+**          of P, F, and D.

+**

+** {H16609} If the destructor D in [sqlite3_create_collation_v2(B,X,E,P,F,D)]

+**          is not NULL then it is called with argument P when the

+**          collating function is dropped by SQLite.

+**

+** {H16612} A collating function is dropped when it is overloaded.

+**

+** {H16615} A collating function is dropped when the database connection

+**          is closed using [sqlite3_close()].

+**

+** {H16618} The pointer P in [sqlite3_create_collation_v2(B,X,E,P,F,D)]

+**          is passed through as the first parameter to the comparison

+**          function F for all subsequent invocations of F.

+**

+** {H16621} A call to [sqlite3_create_collation(B,X,E,P,F)] is exactly

+**          the same as a call to [sqlite3_create_collation_v2()] with

+**          the same parameters and a NULL destructor.

+**

+** {H16624} Following a [sqlite3_create_collation_v2(B,X,E,P,F,D)],

+**          SQLite uses the comparison function F for all text comparison

+**          operations on the [database connection] B on text values that

+**          use the collating sequence named X.

+**

+** {H16627} The [sqlite3_create_collation16(B,X,E,P,F)] works the same

+**          as [sqlite3_create_collation(B,X,E,P,F)] except that the

+**          collation name X is understood as UTF-16 in native byte order

+**          instead of UTF-8.

+**

+** {H16630} When multiple comparison functions are available for the same

+**          collating sequence, SQLite chooses the one whose text encoding

+**          requires the least amount of conversion from the default

+**          text encoding of the database.

+*/

+int sqlite3_create_collation(

+  sqlite3*, 

+  const char *zName, 

+  int eTextRep, 

+  void*,

+  int(*xCompare)(void*,int,const void*,int,const void*)

+);

+int sqlite3_create_collation_v2(

+  sqlite3*, 

+  const char *zName, 

+  int eTextRep, 

+  void*,

+  int(*xCompare)(void*,int,const void*,int,const void*),

+  void(*xDestroy)(void*)

+);

+int sqlite3_create_collation16(

+  sqlite3*, 

+  const void *zName,

+  int eTextRep, 

+  void*,

+  int(*xCompare)(void*,int,const void*,int,const void*)

+);

+

+/*

+** CAPI3REF: Collation Needed Callbacks {H16700} <S20300>

+**

+** To avoid having to register all collation sequences before a database

+** can be used, a single callback function may be registered with the

+** [database connection] to be called whenever an undefined collation

+** sequence is required.

+**

+** If the function is registered using the sqlite3_collation_needed() API,

+** then it is passed the names of undefined collation sequences as strings

+** encoded in UTF-8. {H16703} If sqlite3_collation_needed16() is used,

+** the names are passed as UTF-16 in machine native byte order.

+** A call to either function replaces any existing callback.

+**

+** When the callback is invoked, the first argument passed is a copy

+** of the second argument to sqlite3_collation_needed() or

+** sqlite3_collation_needed16().  The second argument is the database

+** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],

+** or [SQLITE_UTF16LE], indicating the most desirable form of the collation

+** sequence function required.  The fourth parameter is the name of the

+** required collation sequence.

+**

+** The callback function should register the desired collation using

+** [sqlite3_create_collation()], [sqlite3_create_collation16()], or

+** [sqlite3_create_collation_v2()].

+**

+** INVARIANTS:

+**

+** {H16702} A successful call to [sqlite3_collation_needed(D,P,F)]

+**          or [sqlite3_collation_needed16(D,P,F)] causes

+**          the [database connection] D to invoke callback F with first

+**          parameter P whenever it needs a comparison function for a

+**          collating sequence that it does not know about.

+**

+** {H16704} Each successful call to [sqlite3_collation_needed()] or

+**          [sqlite3_collation_needed16()] overrides the callback registered

+**          on the same [database connection] by prior calls to either

+**          interface.

+**

+** {H16706} The name of the requested collating function passed in the

+**          4th parameter to the callback is in UTF-8 if the callback

+**          was registered using [sqlite3_collation_needed()] and

+**          is in UTF-16 native byte order if the callback was

+**          registered using [sqlite3_collation_needed16()].

+*/

+int sqlite3_collation_needed(

+  sqlite3*, 

+  void*, 

+  void(*)(void*,sqlite3*,int eTextRep,const char*)

+);

+int sqlite3_collation_needed16(

+  sqlite3*, 

+  void*,

+  void(*)(void*,sqlite3*,int eTextRep,const void*)

+);

+

+/*

+** Specify the key for an encrypted database.  This routine should be

+** called right after sqlite3_open().

+**

+** The code to implement this API is not available in the public release

+** of SQLite.

+*/

+int sqlite3_key(

+  sqlite3 *db,                   /* Database to be rekeyed */

+  const void *pKey, int nKey     /* The key */

+);

+

+/*

+** Change the key on an open database.  If the current database is not

+** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the

+** database is decrypted.

+**

+** The code to implement this API is not available in the public release

+** of SQLite.

+*/

+int sqlite3_rekey(

+  sqlite3 *db,                   /* Database to be rekeyed */

+  const void *pKey, int nKey     /* The new key */

+);

+

+/*

+** CAPI3REF: Suspend Execution For A Short Time {H10530} <S40410>

+**

+** The sqlite3_sleep() function causes the current thread to suspend execution

+** for at least a number of milliseconds specified in its parameter.

+**

+** If the operating system does not support sleep requests with

+** millisecond time resolution, then the time will be rounded up to

+** the nearest second. The number of milliseconds of sleep actually

+** requested from the operating system is returned.

+**

+** SQLite implements this interface by calling the xSleep()

+** method of the default [sqlite3_vfs] object.

+**

+** INVARIANTS:

+**

+** {H10533} The [sqlite3_sleep(M)] interface invokes the xSleep

+**          method of the default [sqlite3_vfs|VFS] in order to

+**          suspend execution of the current thread for at least

+**          M milliseconds.

+**

+** {H10536} The [sqlite3_sleep(M)] interface returns the number of

+**          milliseconds of sleep actually requested of the operating

+**          system, which might be larger than the parameter M.

+*/

+int sqlite3_sleep(int);

+

+/*

+** CAPI3REF: Name Of The Folder Holding Temporary Files {H10310} <S20000>

+**

+** If this global variable is made to point to a string which is

+** the name of a folder (a.k.a. directory), then all temporary files

+** created by SQLite will be placed in that directory.  If this variable

+** is a NULL pointer, then SQLite performs a search for an appropriate

+** temporary file directory.

+**

+** It is not safe to modify this variable once a [database connection]

+** has been opened.  It is intended that this variable be set once

+** as part of process initialization and before any SQLite interface

+** routines have been call and remain unchanged thereafter.

+*/

+SQLITE_EXTERN char *sqlite3_temp_directory;

+

+/*

+** CAPI3REF: Test For Auto-Commit Mode {H12930} <S60200>

+** KEYWORDS: {autocommit mode}

+**

+** The sqlite3_get_autocommit() interface returns non-zero or

+** zero if the given database connection is or is not in autocommit mode,

+** respectively.  Autocommit mode is on by default.

+** Autocommit mode is disabled by a [BEGIN] statement.

+** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].

+**

+** If certain kinds of errors occur on a statement within a multi-statement

+** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],

+** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the

+** transaction might be rolled back automatically.  The only way to

+** find out whether SQLite automatically rolled back the transaction after

+** an error is to use this function.

+**

+** INVARIANTS:

+**

+** {H12931} The [sqlite3_get_autocommit(D)] interface returns non-zero or

+**          zero if the [database connection] D is or is not in autocommit

+**          mode, respectively.

+**

+** {H12932} Autocommit mode is on by default.

+**

+** {H12933} Autocommit mode is disabled by a successful [BEGIN] statement.

+**

+** {H12934} Autocommit mode is enabled by a successful [COMMIT] or [ROLLBACK]

+**          statement.

+**

+** ASSUMPTIONS:

+**

+** {A12936} If another thread changes the autocommit status of the database

+**          connection while this routine is running, then the return value

+**          is undefined.

+*/

+int sqlite3_get_autocommit(sqlite3*);

+

+/*

+** CAPI3REF: Find The Database Handle Of A Prepared Statement {H13120} <S60600>

+**

+** The sqlite3_db_handle interface returns the [database connection] handle

+** to which a [prepared statement] belongs.  The database handle returned by

+** sqlite3_db_handle is the same database handle that was the first argument

+** to the [sqlite3_prepare_v2()] call (or its variants) that was used to

+** create the statement in the first place.

+**

+** INVARIANTS:

+**

+** {H13123} The [sqlite3_db_handle(S)] interface returns a pointer

+**          to the [database connection] associated with the

+**          [prepared statement] S.

+*/

+sqlite3 *sqlite3_db_handle(sqlite3_stmt*);

+

+/*

+** CAPI3REF: Find the next prepared statement {H13140} <S60600>

+**

+** This interface returns a pointer to the next [prepared statement] after

+** pStmt associated with the [database connection] pDb.  If pStmt is NULL

+** then this interface returns a pointer to the first prepared statement

+** associated with the database connection pDb.  If no prepared statement

+** satisfies the conditions of this routine, it returns NULL.

+**

+** INVARIANTS:

+**

+** {H13143} If D is a [database connection] that holds one or more

+**          unfinalized [prepared statements] and S is a NULL pointer,

+**          then [sqlite3_next_stmt(D, S)] routine shall return a pointer

+**          to one of the prepared statements associated with D.

+**

+** {H13146} If D is a [database connection] that holds no unfinalized

+**          [prepared statements] and S is a NULL pointer, then

+**          [sqlite3_next_stmt(D, S)] routine shall return a NULL pointer.

+**

+** {H13149} If S is a [prepared statement] in the [database connection] D

+**          and S is not the last prepared statement in D, then

+**          [sqlite3_next_stmt(D, S)] routine shall return a pointer

+**          to the next prepared statement in D after S.

+**

+** {H13152} If S is the last [prepared statement] in the

+**          [database connection] D then the [sqlite3_next_stmt(D, S)]

+**          routine shall return a NULL pointer.

+**

+** ASSUMPTIONS:

+**

+** {A13154} The [database connection] pointer D in a call to

+**          [sqlite3_next_stmt(D,S)] must refer to an open database

+**          connection and in particular must not be a NULL pointer.

+*/

+sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);

+

+/*

+** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} <S60400>

+**

+** The sqlite3_commit_hook() interface registers a callback

+** function to be invoked whenever a transaction is committed.

+** Any callback set by a previous call to sqlite3_commit_hook()

+** for the same database connection is overridden.

+** The sqlite3_rollback_hook() interface registers a callback

+** function to be invoked whenever a transaction is committed.

+** Any callback set by a previous call to sqlite3_commit_hook()

+** for the same database connection is overridden.

+** The pArg argument is passed through to the callback.

+** If the callback on a commit hook function returns non-zero,

+** then the commit is converted into a rollback.

+**

+** If another function was previously registered, its

+** pArg value is returned.  Otherwise NULL is returned.

+**

+** Registering a NULL function disables the callback.

+**

+** For the purposes of this API, a transaction is said to have been

+** rolled back if an explicit "ROLLBACK" statement is executed, or

+** an error or constraint causes an implicit rollback to occur.

+** The rollback callback is not invoked if a transaction is

+** automatically rolled back because the database connection is closed.

+** The rollback callback is not invoked if a transaction is

+** rolled back because a commit callback returned non-zero.

+** <todo> Check on this </todo>

+**

+** INVARIANTS:

+**

+** {H12951} The [sqlite3_commit_hook(D,F,P)] interface registers the

+**          callback function F to be invoked with argument P whenever

+**          a transaction commits on the [database connection] D.

+**

+** {H12952} The [sqlite3_commit_hook(D,F,P)] interface returns the P argument

+**          from the previous call with the same [database connection] D,

+**          or NULL on the first call for a particular database connection D.

+**

+** {H12953} Each call to [sqlite3_commit_hook()] overwrites the callback

+**          registered by prior calls.

+**

+** {H12954} If the F argument to [sqlite3_commit_hook(D,F,P)] is NULL

+**          then the commit hook callback is canceled and no callback

+**          is invoked when a transaction commits.

+**

+** {H12955} If the commit callback returns non-zero then the commit is

+**          converted into a rollback.

+**

+** {H12961} The [sqlite3_rollback_hook(D,F,P)] interface registers the

+**          callback function F to be invoked with argument P whenever

+**          a transaction rolls back on the [database connection] D.

+**

+** {H12962} The [sqlite3_rollback_hook(D,F,P)] interface returns the P

+**          argument from the previous call with the same

+**          [database connection] D, or NULL on the first call

+**          for a particular database connection D.

+**

+** {H12963} Each call to [sqlite3_rollback_hook()] overwrites the callback

+**          registered by prior calls.

+**

+** {H12964} If the F argument to [sqlite3_rollback_hook(D,F,P)] is NULL

+**          then the rollback hook callback is canceled and no callback

+**          is invoked when a transaction rolls back.

+*/

+void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);

+void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);

+

+/*

+** CAPI3REF: Data Change Notification Callbacks {H12970} <S60400>

+**

+** The sqlite3_update_hook() interface registers a callback function

+** with the [database connection] identified by the first argument

+** to be invoked whenever a row is updated, inserted or deleted.

+** Any callback set by a previous call to this function

+** for the same database connection is overridden.

+**

+** The second argument is a pointer to the function to invoke when a

+** row is updated, inserted or deleted.

+** The first argument to the callback is a copy of the third argument

+** to sqlite3_update_hook().

+** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],

+** or [SQLITE_UPDATE], depending on the operation that caused the callback

+** to be invoked.

+** The third and fourth arguments to the callback contain pointers to the

+** database and table name containing the affected row.

+** The final callback parameter is the rowid of the row. In the case of

+** an update, this is the rowid after the update takes place.

+**

+** The update hook is not invoked when internal system tables are

+** modified (i.e. sqlite_master and sqlite_sequence).

+**

+** If another function was previously registered, its pArg value

+** is returned.  Otherwise NULL is returned.

+**

+** INVARIANTS:

+**

+** {H12971} The [sqlite3_update_hook(D,F,P)] interface causes the callback

+**          function F to be invoked with first parameter P whenever

+**          a table row is modified, inserted, or deleted on

+**          the [database connection] D.

+**

+** {H12973} The [sqlite3_update_hook(D,F,P)] interface returns the value

+**          of P for the previous call on the same [database connection] D,

+**          or NULL for the first call.

+**

+** {H12975} If the update hook callback F in [sqlite3_update_hook(D,F,P)]

+**          is NULL then the no update callbacks are made.

+**

+** {H12977} Each call to [sqlite3_update_hook(D,F,P)] overrides prior calls

+**          to the same interface on the same [database connection] D.

+**

+** {H12979} The update hook callback is not invoked when internal system

+**          tables such as sqlite_master and sqlite_sequence are modified.

+**

+** {H12981} The second parameter to the update callback

+**          is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],

+**          depending on the operation that caused the callback to be invoked.

+**

+** {H12983} The third and fourth arguments to the callback contain pointers

+**          to zero-terminated UTF-8 strings which are the names of the

+**          database and table that is being updated.

+

+** {H12985} The final callback parameter is the rowid of the row after

+**          the change occurs.

+*/

+void *sqlite3_update_hook(

+  sqlite3*, 

+  void(*)(void *,int ,char const *,char const *,sqlite3_int64),

+  void*

+);

+

+/*

+** CAPI3REF: Enable Or Disable Shared Pager Cache {H10330} <S30900>

+** KEYWORDS: {shared cache} {shared cache mode}

+**

+** This routine enables or disables the sharing of the database cache

+** and schema data structures between [database connection | connections]

+** to the same database. Sharing is enabled if the argument is true

+** and disabled if the argument is false.

+**

+** Cache sharing is enabled and disabled for an entire process. {END}

+** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,

+** sharing was enabled or disabled for each thread separately.

+**

+** The cache sharing mode set by this interface effects all subsequent

+** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].

+** Existing database connections continue use the sharing mode

+** that was in effect at the time they were opened.

+**

+** Virtual tables cannot be used with a shared cache.  When shared

+** cache is enabled, the [sqlite3_create_module()] API used to register

+** virtual tables will always return an error.

+**

+** This routine returns [SQLITE_OK] if shared cache was enabled or disabled

+** successfully.  An [error code] is returned otherwise.

+**

+** Shared cache is disabled by default. But this might change in

+** future releases of SQLite.  Applications that care about shared

+** cache setting should set it explicitly.

+**

+** INVARIANTS:

+**

+** {H10331} A successful invocation of [sqlite3_enable_shared_cache(B)]

+**          will enable or disable shared cache mode for any subsequently

+**          created [database connection] in the same process.

+**

+** {H10336} When shared cache is enabled, the [sqlite3_create_module()]

+**          interface will always return an error.

+**

+** {H10337} The [sqlite3_enable_shared_cache(B)] interface returns

+**          [SQLITE_OK] if shared cache was enabled or disabled successfully.

+**

+** {H10339} Shared cache is disabled by default.

+*/

+int sqlite3_enable_shared_cache(int);

+

+/*

+** CAPI3REF: Attempt To Free Heap Memory {H17340} <S30220>

+**

+** The sqlite3_release_memory() interface attempts to free N bytes

+** of heap memory by deallocating non-essential memory allocations

+** held by the database library. {END}  Memory used to cache database

+** pages to improve performance is an example of non-essential memory.

+** sqlite3_release_memory() returns the number of bytes actually freed,

+** which might be more or less than the amount requested.

+**

+** INVARIANTS:

+**

+** {H17341} The [sqlite3_release_memory(N)] interface attempts to

+**          free N bytes of heap memory by deallocating non-essential

+**          memory allocations held by the database library.

+**

+** {H16342} The [sqlite3_release_memory(N)] returns the number

+**          of bytes actually freed, which might be more or less

+**          than the amount requested.

+*/

+int sqlite3_release_memory(int);

+

+/*

+** CAPI3REF: Impose A Limit On Heap Size {H17350} <S30220>

+**

+** The sqlite3_soft_heap_limit() interface places a "soft" limit

+** on the amount of heap memory that may be allocated by SQLite.

+** If an internal allocation is requested that would exceed the

+** soft heap limit, [sqlite3_release_memory()] is invoked one or

+** more times to free up some space before the allocation is performed.

+**

+** The limit is called "soft", because if [sqlite3_release_memory()]

+** cannot free sufficient memory to prevent the limit from being exceeded,

+** the memory is allocated anyway and the current operation proceeds.

+**

+** A negative or zero value for N means that there is no soft heap limit and

+** [sqlite3_release_memory()] will only be called when memory is exhausted.

+** The default value for the soft heap limit is zero.

+**

+** SQLite makes a best effort to honor the soft heap limit.

+** But if the soft heap limit cannot be honored, execution will

+** continue without error or notification.  This is why the limit is

+** called a "soft" limit.  It is advisory only.

+**

+** Prior to SQLite version 3.5.0, this routine only constrained the memory

+** allocated by a single thread - the same thread in which this routine

+** runs.  Beginning with SQLite version 3.5.0, the soft heap limit is

+** applied to all threads. The value specified for the soft heap limit

+** is an upper bound on the total memory allocation for all threads. In

+** version 3.5.0 there is no mechanism for limiting the heap usage for

+** individual threads.

+**

+** INVARIANTS:

+**

+** {H16351} The [sqlite3_soft_heap_limit(N)] interface places a soft limit

+**          of N bytes on the amount of heap memory that may be allocated

+**          using [sqlite3_malloc()] or [sqlite3_realloc()] at any point

+**          in time.

+**

+** {H16352} If a call to [sqlite3_malloc()] or [sqlite3_realloc()] would

+**          cause the total amount of allocated memory to exceed the

+**          soft heap limit, then [sqlite3_release_memory()] is invoked

+**          in an attempt to reduce the memory usage prior to proceeding

+**          with the memory allocation attempt.

+**

+** {H16353} Calls to [sqlite3_malloc()] or [sqlite3_realloc()] that trigger

+**          attempts to reduce memory usage through the soft heap limit

+**          mechanism continue even if the attempt to reduce memory

+**          usage is unsuccessful.

+**

+** {H16354} A negative or zero value for N in a call to

+**          [sqlite3_soft_heap_limit(N)] means that there is no soft

+**          heap limit and [sqlite3_release_memory()] will only be

+**          called when memory is completely exhausted.

+**

+** {H16355} The default value for the soft heap limit is zero.

+**

+** {H16358} Each call to [sqlite3_soft_heap_limit(N)] overrides the

+**          values set by all prior calls.

+*/

+void sqlite3_soft_heap_limit(int);

+

+/*

+** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} <S60300>

+**

+** This routine returns metadata about a specific column of a specific

+** database table accessible using the [database connection] handle

+** passed as the first function argument.

+**

+** The column is identified by the second, third and fourth parameters to

+** this function. The second parameter is either the name of the database

+** (i.e. "main", "temp" or an attached database) containing the specified

+** table or NULL. If it is NULL, then all attached databases are searched

+** for the table using the same algorithm used by the database engine to

+** resolve unqualified table references.

+**

+** The third and fourth parameters to this function are the table and column

+** name of the desired column, respectively. Neither of these parameters

+** may be NULL.

+**

+** Metadata is returned by writing to the memory locations passed as the 5th

+** and subsequent parameters to this function. Any of these arguments may be

+** NULL, in which case the corresponding element of metadata is omitted.

+**

+** <blockquote>

+** <table border="1">

+** <tr><th> Parameter <th> Output<br>Type <th>  Description

+**

+** <tr><td> 5th <td> const char* <td> Data type

+** <tr><td> 6th <td> const char* <td> Name of default collation sequence

+** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint

+** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY

+** <tr><td> 9th <td> int         <td> True if column is AUTOINCREMENT

+** </table>

+** </blockquote>

+**

+** The memory pointed to by the character pointers returned for the

+** declaration type and collation sequence is valid only until the next

+** call to any SQLite API function.

+**

+** If the specified table is actually a view, an [error code] is returned.

+**

+** If the specified column is "rowid", "oid" or "_rowid_" and an

+** INTEGER PRIMARY KEY column has been explicitly declared, then the output

+** parameters are set for the explicitly declared column. If there is no

+** explicitly declared INTEGER PRIMARY KEY column, then the output

+** parameters are set as follows:

+**

+** <pre>

+**     data type: "INTEGER"

+**     collation sequence: "BINARY"

+**     not null: 0

+**     primary key: 1

+**     auto increment: 0

+** </pre>

+**

+** This function may load one or more schemas from database files. If an

+** error occurs during this process, or if the requested table or column

+** cannot be found, an [error code] is returned and an error message left

+** in the [database connection] (to be retrieved using sqlite3_errmsg()).

+**

+** This API is only available if the library was compiled with the

+** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.

+*/

+int sqlite3_table_column_metadata(

+  sqlite3 *db,                /* Connection handle */

+  const char *zDbName,        /* Database name or NULL */

+  const char *zTableName,     /* Table name */

+  const char *zColumnName,    /* Column name */

+  char const **pzDataType,    /* OUTPUT: Declared data type */

+  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */

+  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */

+  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */

+  int *pAutoinc               /* OUTPUT: True if column is auto-increment */

+);

+

+/*

+** CAPI3REF: Load An Extension {H12600} <S20500>

+**

+** This interface loads an SQLite extension library from the named file.

+**

+** {H12601} The sqlite3_load_extension() interface attempts to load an

+**          SQLite extension library contained in the file zFile.

+**

+** {H12602} The entry point is zProc.

+**

+** {H12603} zProc may be 0, in which case the name of the entry point

+**          defaults to "sqlite3_extension_init".

+**

+** {H12604} The sqlite3_load_extension() interface shall return

+**          [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.

+**

+** {H12605} If an error occurs and pzErrMsg is not 0, then the

+**          [sqlite3_load_extension()] interface shall attempt to

+**          fill *pzErrMsg with error message text stored in memory

+**          obtained from [sqlite3_malloc()]. {END}  The calling function

+**          should free this memory by calling [sqlite3_free()].

+**

+** {H12606} Extension loading must be enabled using

+**          [sqlite3_enable_load_extension()] prior to calling this API,

+**          otherwise an error will be returned.

+*/

+int sqlite3_load_extension(

+  sqlite3 *db,          /* Load the extension into this database connection */

+  const char *zFile,    /* Name of the shared library containing extension */

+  const char *zProc,    /* Entry point.  Derived from zFile if 0 */

+  char **pzErrMsg       /* Put error message here if not 0 */

+);

+

+/*

+** CAPI3REF: Enable Or Disable Extension Loading {H12620} <S20500>

+**

+** So as not to open security holes in older applications that are

+** unprepared to deal with extension loading, and as a means of disabling

+** extension loading while evaluating user-entered SQL, the following API

+** is provided to turn the [sqlite3_load_extension()] mechanism on and off.

+**

+** Extension loading is off by default. See ticket #1863.

+**

+** {H12621} Call the sqlite3_enable_load_extension() routine with onoff==1

+**          to turn extension loading on and call it with onoff==0 to turn

+**          it back off again.

+**

+** {H12622} Extension loading is off by default.

+*/

+int sqlite3_enable_load_extension(sqlite3 *db, int onoff);

+

+/*

+** CAPI3REF: Automatically Load An Extensions {H12640} <S20500>

+**

+** This API can be invoked at program startup in order to register

+** one or more statically linked extensions that will be available

+** to all new [database connections]. {END}

+**

+** This routine stores a pointer to the extension in an array that is

+** obtained from [sqlite3_malloc()].  If you run a memory leak checker

+** on your program and it reports a leak because of this array, invoke

+** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory.

+**

+** {H12641} This function registers an extension entry point that is

+**          automatically invoked whenever a new [database connection]

+**          is opened using [sqlite3_open()], [sqlite3_open16()],

+**          or [sqlite3_open_v2()].

+**

+** {H12642} Duplicate extensions are detected so calling this routine

+**          multiple times with the same extension is harmless.

+**

+** {H12643} This routine stores a pointer to the extension in an array

+**          that is obtained from [sqlite3_malloc()].

+**

+** {H12644} Automatic extensions apply across all threads.

+*/

+int sqlite3_auto_extension(void *xEntryPoint);

+

+/*

+** CAPI3REF: Reset Automatic Extension Loading {H12660} <S20500>

+**

+** This function disables all previously registered automatic

+** extensions. {END}  It undoes the effect of all prior

+** [sqlite3_auto_extension()] calls.

+**

+** {H12661} This function disables all previously registered

+**          automatic extensions.

+**

+** {H12662} This function disables automatic extensions in all threads.

+*/

+void sqlite3_reset_auto_extension(void);

+

+/*

+****** EXPERIMENTAL - subject to change without notice **************

+**

+** The interface to the virtual-table mechanism is currently considered

+** to be experimental.  The interface might change in incompatible ways.

+** If this is a problem for you, do not use the interface at this time.

+**

+** When the virtual-table mechanism stabilizes, we will declare the

+** interface fixed, support it indefinitely, and remove this comment.

+*/

+

+/*

+** Structures used by the virtual table interface

+*/

+typedef struct sqlite3_vtab sqlite3_vtab;

+typedef struct sqlite3_index_info sqlite3_index_info;

+typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;

+typedef struct sqlite3_module sqlite3_module;

+

+/*

+** CAPI3REF: Virtual Table Object {H18000} <S20400>

+** KEYWORDS: sqlite3_module

+** EXPERIMENTAL

+**

+** A module is a class of virtual tables.  Each module is defined

+** by an instance of the following structure.  This structure consists

+** mostly of methods for the module.

+**

+** This interface is experimental and is subject to change or

+** removal in future releases of SQLite.

+*/

+struct sqlite3_module {

+  int iVersion;

+  int (*xCreate)(sqlite3*, void *pAux,

+               int argc, const char *const*argv,

+               sqlite3_vtab **ppVTab, char**);

+  int (*xConnect)(sqlite3*, void *pAux,

+               int argc, const char *const*argv,

+               sqlite3_vtab **ppVTab, char**);

+  int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);

+  int (*xDisconnect)(sqlite3_vtab *pVTab);

+  int (*xDestroy)(sqlite3_vtab *pVTab);

+  int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);

+  int (*xClose)(sqlite3_vtab_cursor*);

+  int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,

+                int argc, sqlite3_value **argv);

+  int (*xNext)(sqlite3_vtab_cursor*);

+  int (*xEof)(sqlite3_vtab_cursor*);

+  int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);

+  int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);

+  int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);

+  int (*xBegin)(sqlite3_vtab *pVTab);

+  int (*xSync)(sqlite3_vtab *pVTab);

+  int (*xCommit)(sqlite3_vtab *pVTab);

+  int (*xRollback)(sqlite3_vtab *pVTab);

+  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,

+                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),

+                       void **ppArg);

+  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);

+};

+

+/*

+** CAPI3REF: Virtual Table Indexing Information {H18100} <S20400>

+** KEYWORDS: sqlite3_index_info

+** EXPERIMENTAL

+**

+** The sqlite3_index_info structure and its substructures is used to

+** pass information into and receive the reply from the xBestIndex

+** method of an sqlite3_module.  The fields under **Inputs** are the

+** inputs to xBestIndex and are read-only.  xBestIndex inserts its

+** results into the **Outputs** fields.

+**

+** The aConstraint[] array records WHERE clause constraints of the form:

+**

+** <pre>column OP expr</pre>

+**

+** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.  The particular operator is

+** stored in aConstraint[].op.  The index of the column is stored in

+** aConstraint[].iColumn.  aConstraint[].usable is TRUE if the

+** expr on the right-hand side can be evaluated (and thus the constraint

+** is usable) and false if it cannot.

+**

+** The optimizer automatically inverts terms of the form "expr OP column"

+** and makes other simplifications to the WHERE clause in an attempt to

+** get as many WHERE clause terms into the form shown above as possible.

+** The aConstraint[] array only reports WHERE clause terms in the correct

+** form that refer to the particular virtual table being queried.

+**

+** Information about the ORDER BY clause is stored in aOrderBy[].

+** Each term of aOrderBy records a column of the ORDER BY clause.

+**

+** The xBestIndex method must fill aConstraintUsage[] with information

+** about what parameters to pass to xFilter.  If argvIndex>0 then

+** the right-hand side of the corresponding aConstraint[] is evaluated

+** and becomes the argvIndex-th entry in argv.  If aConstraintUsage[].omit

+** is true, then the constraint is assumed to be fully handled by the

+** virtual table and is not checked again by SQLite.

+**

+** The idxNum and idxPtr values are recorded and passed into xFilter.

+** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true.

+**

+** The orderByConsumed means that output from xFilter will occur in

+** the correct order to satisfy the ORDER BY clause so that no separate

+** sorting step is required.

+**

+** The estimatedCost value is an estimate of the cost of doing the

+** particular lookup.  A full scan of a table with N entries should have

+** a cost of N.  A binary search of a table of N entries should have a

+** cost of approximately log(N).

+**

+** This interface is experimental and is subject to change or

+** removal in future releases of SQLite.

+*/

+struct sqlite3_index_info {

+  /* Inputs */

+  int nConstraint;           /* Number of entries in aConstraint */

+  struct sqlite3_index_constraint {

+     int iColumn;              /* Column on left-hand side of constraint */

+     unsigned char op;         /* Constraint operator */

+     unsigned char usable;     /* True if this constraint is usable */

+     int iTermOffset;          /* Used internally - xBestIndex should ignore */

+  } *aConstraint;            /* Table of WHERE clause constraints */

+  int nOrderBy;              /* Number of terms in the ORDER BY clause */

+  struct sqlite3_index_orderby {

+     int iColumn;              /* Column number */

+     unsigned char desc;       /* True for DESC.  False for ASC. */

+  } *aOrderBy;               /* The ORDER BY clause */

+  /* Outputs */

+  struct sqlite3_index_constraint_usage {

+    int argvIndex;           /* if >0, constraint is part of argv to xFilter */

+    unsigned char omit;      /* Do not code a test for this constraint */

+  } *aConstraintUsage;

+  int idxNum;                /* Number used to identify the index */

+  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */

+  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */

+  int orderByConsumed;       /* True if output is already ordered */

+  double estimatedCost;      /* Estimated cost of using this index */

+};

+#define SQLITE_INDEX_CONSTRAINT_EQ    2

+#define SQLITE_INDEX_CONSTRAINT_GT    4

+#define SQLITE_INDEX_CONSTRAINT_LE    8

+#define SQLITE_INDEX_CONSTRAINT_LT    16

+#define SQLITE_INDEX_CONSTRAINT_GE    32

+#define SQLITE_INDEX_CONSTRAINT_MATCH 64

+

+/*

+** CAPI3REF: Register A Virtual Table Implementation {H18200} <S20400>

+** EXPERIMENTAL

+**

+** This routine is used to register a new module name with a

+** [database connection].  Module names must be registered before

+** creating new virtual tables on the module, or before using

+** preexisting virtual tables of the module.

+**

+** This interface is experimental and is subject to change or

+** removal in future releases of SQLite.

+*/

+int sqlite3_create_module(

+  sqlite3 *db,               /* SQLite connection to register module with */

+  const char *zName,         /* Name of the module */

+  const sqlite3_module *,    /* Methods for the module */

+  void *                     /* Client data for xCreate/xConnect */

+);

+

+/*

+** CAPI3REF: Register A Virtual Table Implementation {H18210} <S20400>

+** EXPERIMENTAL

+**

+** This routine is identical to the [sqlite3_create_module()] method above,

+** except that it allows a destructor function to be specified. It is

+** even more experimental than the rest of the virtual tables API.

+*/

+int sqlite3_create_module_v2(

+  sqlite3 *db,               /* SQLite connection to register module with */

+  const char *zName,         /* Name of the module */

+  const sqlite3_module *,    /* Methods for the module */

+  void *,                    /* Client data for xCreate/xConnect */

+  void(*xDestroy)(void*)     /* Module destructor function */

+);

+

+/*

+** CAPI3REF: Virtual Table Instance Object {H18010} <S20400>

+** KEYWORDS: sqlite3_vtab

+** EXPERIMENTAL

+**

+** Every module implementation uses a subclass of the following structure

+** to describe a particular instance of the module.  Each subclass will

+** be tailored to the specific needs of the module implementation.

+** The purpose of this superclass is to define certain fields that are

+** common to all module implementations.

+**

+** Virtual tables methods can set an error message by assigning a

+** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should

+** take care that any prior string is freed by a call to [sqlite3_free()]

+** prior to assigning a new string to zErrMsg.  After the error message

+** is delivered up to the client application, the string will be automatically

+** freed by sqlite3_free() and the zErrMsg field will be zeroed.  Note

+** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field

+** since virtual tables are commonly implemented in loadable extensions which

+** do not have access to sqlite3MPrintf() or sqlite3Free().

+**

+** This interface is experimental and is subject to change or

+** removal in future releases of SQLite.

+*/

+struct sqlite3_vtab {

+  const sqlite3_module *pModule;  /* The module for this virtual table */

+  int nRef;                       /* Used internally */

+  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */

+  /* Virtual table implementations will typically add additional fields */

+};

+

+/*

+** CAPI3REF: Virtual Table Cursor Object  {H18020} <S20400>

+** KEYWORDS: sqlite3_vtab_cursor

+** EXPERIMENTAL

+**

+** Every module implementation uses a subclass of the following structure

+** to describe cursors that point into the virtual table and are used

+** to loop through the virtual table.  Cursors are created using the

+** xOpen method of the module.  Each module implementation will define

+** the content of a cursor structure to suit its own needs.

+**

+** This superclass exists in order to define fields of the cursor that

+** are common to all implementations.

+**

+** This interface is experimental and is subject to change or

+** removal in future releases of SQLite.

+*/

+struct sqlite3_vtab_cursor {

+  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */

+  /* Virtual table implementations will typically add additional fields */

+};

+

+/*

+** CAPI3REF: Declare The Schema Of A Virtual Table {H18280} <S20400>

+** EXPERIMENTAL

+**

+** The xCreate and xConnect methods of a module use the following API

+** to declare the format (the names and datatypes of the columns) of

+** the virtual tables they implement.

+**

+** This interface is experimental and is subject to change or

+** removal in future releases of SQLite.

+*/

+int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);

+

+/*

+** CAPI3REF: Overload A Function For A Virtual Table {H18300} <S20400>

+** EXPERIMENTAL

+**

+** Virtual tables can provide alternative implementations of functions

+** using the xFindFunction method.  But global versions of those functions

+** must exist in order to be overloaded.

+**

+** This API makes sure a global version of a function with a particular

+** name and number of parameters exists.  If no such function exists

+** before this API is called, a new function is created.  The implementation

+** of the new function always causes an exception to be thrown.  So

+** the new function is not good for anything by itself.  Its only

+** purpose is to be a placeholder function that can be overloaded

+** by virtual tables.

+**

+** This API should be considered part of the virtual table interface,

+** which is experimental and subject to change.

+*/

+int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);

+

+/*

+** The interface to the virtual-table mechanism defined above (back up

+** to a comment remarkably similar to this one) is currently considered

+** to be experimental.  The interface might change in incompatible ways.

+** If this is a problem for you, do not use the interface at this time.

+**

+** When the virtual-table mechanism stabilizes, we will declare the

+** interface fixed, support it indefinitely, and remove this comment.

+**

+****** EXPERIMENTAL - subject to change without notice **************

+*/

+

+/*

+** CAPI3REF: A Handle To An Open BLOB {H17800} <S30230>

+** KEYWORDS: {BLOB handle} {BLOB handles}

+**

+** An instance of this object represents an open BLOB on which

+** [sqlite3_blob_open | incremental BLOB I/O] can be performed.

+** Objects of this type are created by [sqlite3_blob_open()]

+** and destroyed by [sqlite3_blob_close()].

+** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces

+** can be used to read or write small subsections of the BLOB.

+** The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.

+*/

+typedef struct sqlite3_blob sqlite3_blob;

+

+/*

+** CAPI3REF: Open A BLOB For Incremental I/O {H17810} <S30230>

+**

+** This interfaces opens a [BLOB handle | handle] to the BLOB located

+** in row iRow, column zColumn, table zTable in database zDb;

+** in other words, the same BLOB that would be selected by:

+**

+** <pre>

+**     SELECT zColumn FROM zDb.zTable WHERE rowid = iRow;

+** </pre> {END}

+**

+** If the flags parameter is non-zero, the the BLOB is opened for read

+** and write access. If it is zero, the BLOB is opened for read access.

+**

+** Note that the database name is not the filename that contains

+** the database but rather the symbolic name of the database that

+** is assigned when the database is connected using [ATTACH].

+** For the main database file, the database name is "main".

+** For TEMP tables, the database name is "temp".

+**

+** On success, [SQLITE_OK] is returned and the new [BLOB handle] is written

+** to *ppBlob. Otherwise an [error code] is returned and any value written

+** to *ppBlob should not be used by the caller.

+** This function sets the [database connection] error code and message

+** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].

+**

+** If the row that a BLOB handle points to is modified by an

+** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects

+** then the BLOB handle is marked as "expired".

+** This is true if any column of the row is changed, even a column

+** other than the one the BLOB handle is open on.

+** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for

+** a expired BLOB handle fail with an return code of [SQLITE_ABORT].

+** Changes written into a BLOB prior to the BLOB expiring are not

+** rollback by the expiration of the BLOB.  Such changes will eventually

+** commit if the transaction continues to completion.

+**

+** INVARIANTS:

+**

+** {H17813} A successful invocation of the [sqlite3_blob_open(D,B,T,C,R,F,P)]

+**          interface shall open an [sqlite3_blob] object P on the BLOB

+**          in column C of the table T in the database B on

+**          the [database connection] D.

+**

+** {H17814} A successful invocation of [sqlite3_blob_open(D,...)] shall start

+**          a new transaction on the [database connection] D if that

+**          connection is not already in a transaction.

+**

+** {H17816} The [sqlite3_blob_open(D,B,T,C,R,F,P)] interface shall open

+**          the BLOB for read and write access if and only if the F

+**          parameter is non-zero.

+**

+** {H17819} The [sqlite3_blob_open()] interface shall return [SQLITE_OK] on

+**          success and an appropriate [error code] on failure.

+**

+** {H17821} If an error occurs during evaluation of [sqlite3_blob_open(D,...)]

+**          then subsequent calls to [sqlite3_errcode(D)],

+**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return

+**          information appropriate for that error.

+**

+** {H17824} If any column in the row that a [sqlite3_blob] has open is

+**          changed by a separate [UPDATE] or [DELETE] statement or by

+**          an [ON CONFLICT] side effect, then the [sqlite3_blob] shall

+**          be marked as invalid.

+*/

+int sqlite3_blob_open(

+  sqlite3*,

+  const char *zDb,

+  const char *zTable,

+  const char *zColumn,

+  sqlite3_int64 iRow,

+  int flags,

+  sqlite3_blob **ppBlob

+);

+

+/*

+** CAPI3REF: Close A BLOB Handle {H17830} <S30230>

+**

+** Closes an open [BLOB handle].

+**

+** Closing a BLOB shall cause the current transaction to commit

+** if there are no other BLOBs, no pending prepared statements, and the

+** database connection is in [autocommit mode].

+** If any writes were made to the BLOB, they might be held in cache

+** until the close operation if they will fit. {END}

+**

+** Closing the BLOB often forces the changes

+** out to disk and so if any I/O errors occur, they will likely occur

+** at the time when the BLOB is closed.  {H17833} Any errors that occur during

+** closing are reported as a non-zero return value.

+**

+** The BLOB is closed unconditionally.  Even if this routine returns

+** an error code, the BLOB is still closed.

+**

+** INVARIANTS:

+**

+** {H17833} The [sqlite3_blob_close(P)] interface closes an [sqlite3_blob]

+**          object P previously opened using [sqlite3_blob_open()].

+**

+** {H17836} Closing an [sqlite3_blob] object using

+**          [sqlite3_blob_close()] shall cause the current transaction to

+**          commit if there are no other open [sqlite3_blob] objects

+**          or [prepared statements] on the same [database connection] and

+**          the database connection is in [autocommit mode].

+**

+** {H17839} The [sqlite3_blob_close(P)] interfaces shall close the

+**          [sqlite3_blob] object P unconditionally, even if

+**          [sqlite3_blob_close(P)] returns something other than [SQLITE_OK].

+*/

+int sqlite3_blob_close(sqlite3_blob *);

+

+/*

+** CAPI3REF: Return The Size Of An Open BLOB {H17840} <S30230>

+**

+** Returns the size in bytes of the BLOB accessible via the open

+** []BLOB handle] in its only argument.

+**

+** INVARIANTS:

+**

+** {H17843} The [sqlite3_blob_bytes(P)] interface returns the size

+**          in bytes of the BLOB that the [sqlite3_blob] object P

+**          refers to.

+*/

+int sqlite3_blob_bytes(sqlite3_blob *);

+

+/*

+** CAPI3REF: Read Data From A BLOB Incrementally {H17850} <S30230>

+**

+** This function is used to read data from an open [BLOB handle] into a

+** caller-supplied buffer. N bytes of data are copied into buffer Z

+** from the open BLOB, starting at offset iOffset.

+**

+** If offset iOffset is less than N bytes from the end of the BLOB,

+** [SQLITE_ERROR] is returned and no data is read.  If N or iOffset is

+** less than zero, [SQLITE_ERROR] is returned and no data is read.

+**

+** An attempt to read from an expired [BLOB handle] fails with an

+** error code of [SQLITE_ABORT].

+**

+** On success, SQLITE_OK is returned.

+** Otherwise, an [error code] or an [extended error code] is returned.

+**

+** INVARIANTS:

+**

+** {H17853} A successful invocation of [sqlite3_blob_read(P,Z,N,X)] 

+**          shall reads N bytes of data out of the BLOB referenced by

+**          [BLOB handle] P beginning at offset X and store those bytes

+**          into buffer Z.

+**

+** {H17856} In [sqlite3_blob_read(P,Z,N,X)] if the size of the BLOB

+**          is less than N+X bytes, then the function shall leave the

+**          Z buffer unchanged and return [SQLITE_ERROR].

+**

+** {H17859} In [sqlite3_blob_read(P,Z,N,X)] if X or N is less than zero

+**          then the function shall leave the Z buffer unchanged

+**          and return [SQLITE_ERROR].

+**

+** {H17862} The [sqlite3_blob_read(P,Z,N,X)] interface shall return [SQLITE_OK]

+**          if N bytes are successfully read into buffer Z.

+**

+** {H17863} If the [BLOB handle] P is expired and X and N are within bounds

+**          then [sqlite3_blob_read(P,Z,N,X)] shall leave the Z buffer

+**          unchanged and return [SQLITE_ABORT].

+**

+** {H17865} If the requested read could not be completed,

+**          the [sqlite3_blob_read(P,Z,N,X)] interface shall return an

+**          appropriate [error code] or [extended error code].

+**

+** {H17868} If an error occurs during evaluation of [sqlite3_blob_read(P,...)]

+**          then subsequent calls to [sqlite3_errcode(D)],

+**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return

+**          information appropriate for that error, where D is the

+**          [database connection] that was used to open the [BLOB handle] P.

+*/

+int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

+

+/*

+** CAPI3REF: Write Data Into A BLOB Incrementally {H17870} <S30230>

+**

+** This function is used to write data into an open [BLOB handle] from a

+** caller-supplied buffer. N bytes of data are copied from the buffer Z

+** into the open BLOB, starting at offset iOffset.

+**

+** If the [BLOB handle] passed as the first argument was not opened for

+** writing (the flags parameter to [sqlite3_blob_open()] was zero),

+** this function returns [SQLITE_READONLY].

+**

+** This function may only modify the contents of the BLOB; it is

+** not possible to increase the size of a BLOB using this API.

+** If offset iOffset is less than N bytes from the end of the BLOB,

+** [SQLITE_ERROR] is returned and no data is written.  If N is

+** less than zero [SQLITE_ERROR] is returned and no data is written.

+**

+** An attempt to write to an expired [BLOB handle] fails with an

+** error code of [SQLITE_ABORT].  Writes to the BLOB that occurred

+** before the [BLOB handle] expired are not rolled back by the

+** expiration of the handle, though of course those changes might

+** have been overwritten by the statement that expired the BLOB handle

+** or by other independent statements.

+**

+** On success, SQLITE_OK is returned.

+** Otherwise, an  [error code] or an [extended error code] is returned.

+**

+** INVARIANTS:

+**

+** {H17873} A successful invocation of [sqlite3_blob_write(P,Z,N,X)]

+**          shall write N bytes of data from buffer Z into the BLOB 

+**          referenced by [BLOB handle] P beginning at offset X into

+**          the BLOB.

+**

+** {H17874} In the absence of other overridding changes, the changes

+**          written to a BLOB by [sqlite3_blob_write()] shall

+**          remain in effect after the associated [BLOB handle] expires.

+**

+** {H17875} If the [BLOB handle] P was opened for reading only then

+**          an invocation of [sqlite3_blob_write(P,Z,N,X)] shall leave

+**          the referenced BLOB unchanged and return [SQLITE_READONLY].

+**

+** {H17876} If the size of the BLOB referenced by [BLOB handle] P is

+**          less than N+X bytes then [sqlite3_blob_write(P,Z,N,X)] shall

+**          leave the BLOB unchanged and return [SQLITE_ERROR].

+**

+** {H17877} If the [BLOB handle] P is expired and X and N are within bounds

+**          then [sqlite3_blob_read(P,Z,N,X)] shall leave the BLOB

+**          unchanged and return [SQLITE_ABORT].

+**

+** {H17879} If X or N are less than zero then [sqlite3_blob_write(P,Z,N,X)]

+**          shall leave the BLOB referenced by [BLOB handle] P unchanged

+**          and return [SQLITE_ERROR].

+**

+** {H17882} The [sqlite3_blob_write(P,Z,N,X)] interface shall return

+**          [SQLITE_OK] if N bytes where successfully written into the BLOB.

+**

+** {H17885} If the requested write could not be completed,

+**          the [sqlite3_blob_write(P,Z,N,X)] interface shall return an

+**          appropriate [error code] or [extended error code].

+**

+** {H17888} If an error occurs during evaluation of [sqlite3_blob_write(D,...)]

+**          then subsequent calls to [sqlite3_errcode(D)],

+**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return

+**          information appropriate for that error.

+*/

+int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

+

+/* Begin preload-cache.patch for Chromium */

+/*

+** Preload the databases into the pager cache, up to the maximum size of the

+** pager cache.

+**

+** For a database to be loaded successfully, the pager must be active. That is,

+** there must be an open statement on that database. See sqlite3pager_loadall

+**

+** There might be many databases attached to the given connection. We iterate

+** them all and try to load them. If none are loadable successfully, we return

+** an error. Otherwise, we return OK.

+*/

+int sqlite3Preload(sqlite3 *db);

+/* End preload-cache.patch for Chromium */

+

+/*

+** CAPI3REF: Virtual File System Objects {H11200} <S20100>

+**

+** A virtual filesystem (VFS) is an [sqlite3_vfs] object

+** that SQLite uses to interact

+** with the underlying operating system.  Most SQLite builds come with a

+** single default VFS that is appropriate for the host computer.

+** New VFSes can be registered and existing VFSes can be unregistered.

+** The following interfaces are provided.

+**

+** The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.

+** Names are case sensitive.

+** Names are zero-terminated UTF-8 strings.

+** If there is no match, a NULL pointer is returned.

+** If zVfsName is NULL then the default VFS is returned.

+**

+** New VFSes are registered with sqlite3_vfs_register().

+** Each new VFS becomes the default VFS if the makeDflt flag is set.

+** The same VFS can be registered multiple times without injury.

+** To make an existing VFS into the default VFS, register it again

+** with the makeDflt flag set.  If two different VFSes with the

+** same name are registered, the behavior is undefined.  If a

+** VFS is registered with a name that is NULL or an empty string,

+** then the behavior is undefined.

+**

+** Unregister a VFS with the sqlite3_vfs_unregister() interface.

+** If the default VFS is unregistered, another VFS is chosen as

+** the default.  The choice for the new VFS is arbitrary.

+**

+** INVARIANTS:

+**

+** {H11203} The [sqlite3_vfs_find(N)] interface returns a pointer to the

+**          registered [sqlite3_vfs] object whose name exactly matches

+**          the zero-terminated UTF-8 string N, or it returns NULL if

+**          there is no match.

+**

+** {H11206} If the N parameter to [sqlite3_vfs_find(N)] is NULL then

+**          the function returns a pointer to the default [sqlite3_vfs]

+**          object if there is one, or NULL if there is no default

+**          [sqlite3_vfs] object.

+**

+** {H11209} The [sqlite3_vfs_register(P,F)] interface registers the

+**          well-formed [sqlite3_vfs] object P using the name given

+**          by the zName field of the object.

+**

+** {H11212} Using the [sqlite3_vfs_register(P,F)] interface to register

+**          the same [sqlite3_vfs] object multiple times is a harmless no-op.

+**

+** {H11215} The [sqlite3_vfs_register(P,F)] interface makes the [sqlite3_vfs]

+**          object P the default [sqlite3_vfs] object if F is non-zero.

+**

+** {H11218} The [sqlite3_vfs_unregister(P)] interface unregisters the

+**          [sqlite3_vfs] object P so that it is no longer returned by

+**          subsequent calls to [sqlite3_vfs_find()].

+*/

+sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);

+int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);

+int sqlite3_vfs_unregister(sqlite3_vfs*);

+

+/*

+** CAPI3REF: Mutexes {H17000} <S20000>

+**

+** The SQLite core uses these routines for thread

+** synchronization. Though they are intended for internal

+** use by SQLite, code that links against SQLite is

+** permitted to use any of these routines.

+**

+** The SQLite source code contains multiple implementations

+** of these mutex routines.  An appropriate implementation

+** is selected automatically at compile-time.  The following

+** implementations are available in the SQLite core:

+**

+** <ul>

+** <li>   SQLITE_MUTEX_OS2

+** <li>   SQLITE_MUTEX_PTHREAD

+** <li>   SQLITE_MUTEX_W32

+** <li>   SQLITE_MUTEX_NOOP

+** </ul>

+**

+** The SQLITE_MUTEX_NOOP implementation is a set of routines

+** that does no real locking and is appropriate for use in

+** a single-threaded application.  The SQLITE_MUTEX_OS2,

+** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations

+** are appropriate for use on OS/2, Unix, and Windows.

+**

+** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor

+** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex

+** implementation is included with the library. In this case the

+** application must supply a custom mutex implementation using the

+** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function

+** before calling sqlite3_initialize() or any other public sqlite3_

+** function that calls sqlite3_initialize().

+**

+** {H17011} The sqlite3_mutex_alloc() routine allocates a new

+** mutex and returns a pointer to it. {H17012} If it returns NULL

+** that means that a mutex could not be allocated. {H17013} SQLite

+** will unwind its stack and return an error. {H17014} The argument

+** to sqlite3_mutex_alloc() is one of these integer constants:

+**

+** <ul>

+** <li>  SQLITE_MUTEX_FAST

+** <li>  SQLITE_MUTEX_RECURSIVE

+** <li>  SQLITE_MUTEX_STATIC_MASTER

+** <li>  SQLITE_MUTEX_STATIC_MEM

+** <li>  SQLITE_MUTEX_STATIC_MEM2

+** <li>  SQLITE_MUTEX_STATIC_PRNG

+** <li>  SQLITE_MUTEX_STATIC_LRU

+** <li>  SQLITE_MUTEX_STATIC_LRU2

+** </ul>

+**

+** {H17015} The first two constants cause sqlite3_mutex_alloc() to create

+** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE

+** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END}

+** The mutex implementation does not need to make a distinction

+** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does

+** not want to.  {H17016} But SQLite will only request a recursive mutex in

+** cases where it really needs one.  {END} If a faster non-recursive mutex

+** implementation is available on the host platform, the mutex subsystem

+** might return such a mutex in response to SQLITE_MUTEX_FAST.

+**

+** {H17017} The other allowed parameters to sqlite3_mutex_alloc() each return

+** a pointer to a static preexisting mutex. {END}  Four static mutexes are

+** used by the current version of SQLite.  Future versions of SQLite

+** may add additional static mutexes.  Static mutexes are for internal

+** use by SQLite only.  Applications that use SQLite mutexes should

+** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or

+** SQLITE_MUTEX_RECURSIVE.

+**

+** {H17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST

+** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()

+** returns a different mutex on every call.  {H17034} But for the static

+** mutex types, the same mutex is returned on every call that has

+** the same type number.

+**

+** {H17019} The sqlite3_mutex_free() routine deallocates a previously

+** allocated dynamic mutex. {H17020} SQLite is careful to deallocate every

+** dynamic mutex that it allocates. {A17021} The dynamic mutexes must not be in

+** use when they are deallocated. {A17022} Attempting to deallocate a static

+** mutex results in undefined behavior. {H17023} SQLite never deallocates

+** a static mutex. {END}

+**

+** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt

+** to enter a mutex. {H17024} If another thread is already within the mutex,

+** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return

+** SQLITE_BUSY. {H17025}  The sqlite3_mutex_try() interface returns [SQLITE_OK]

+** upon successful entry.  {H17026} Mutexes created using

+** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.

+** {H17027} In such cases the,

+** mutex must be exited an equal number of times before another thread

+** can enter.  {A17028} If the same thread tries to enter any other

+** kind of mutex more than once, the behavior is undefined.

+** {H17029} SQLite will never exhibit

+** such behavior in its own use of mutexes.

+**

+** Some systems (for example, Windows 95) do not support the operation

+** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()

+** will always return SQLITE_BUSY.  {H17030} The SQLite core only ever uses

+** sqlite3_mutex_try() as an optimization so this is acceptable behavior.

+**

+** {H17031} The sqlite3_mutex_leave() routine exits a mutex that was

+** previously entered by the same thread.  {A17032} The behavior

+** is undefined if the mutex is not currently entered by the

+** calling thread or is not currently allocated.  {H17033} SQLite will

+** never do either. {END}

+**

+** If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or

+** sqlite3_mutex_leave() is a NULL pointer, then all three routines

+** behave as no-ops.

+**

+** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].

+*/

+sqlite3_mutex *sqlite3_mutex_alloc(int);

+void sqlite3_mutex_free(sqlite3_mutex*);

+void sqlite3_mutex_enter(sqlite3_mutex*);

+int sqlite3_mutex_try(sqlite3_mutex*);

+void sqlite3_mutex_leave(sqlite3_mutex*);

+

+/*

+** CAPI3REF: Mutex Methods Object {H17120} <S20130>

+** EXPERIMENTAL

+**

+** An instance of this structure defines the low-level routines

+** used to allocate and use mutexes.

+**

+** Usually, the default mutex implementations provided by SQLite are

+** sufficient, however the user has the option of substituting a custom

+** implementation for specialized deployments or systems for which SQLite

+** does not provide a suitable implementation. In this case, the user

+** creates and populates an instance of this structure to pass

+** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.

+** Additionally, an instance of this structure can be used as an

+** output variable when querying the system for the current mutex

+** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.

+**

+** The xMutexInit method defined by this structure is invoked as

+** part of system initialization by the sqlite3_initialize() function.

+** {H17001} The xMutexInit routine shall be called by SQLite once for each

+** effective call to [sqlite3_initialize()].

+**

+** The xMutexEnd method defined by this structure is invoked as

+** part of system shutdown by the sqlite3_shutdown() function. The

+** implementation of this method is expected to release all outstanding

+** resources obtained by the mutex methods implementation, especially

+** those obtained by the xMutexInit method. {H17003} The xMutexEnd()

+** interface shall be invoked once for each call to [sqlite3_shutdown()].

+**

+** The remaining seven methods defined by this structure (xMutexAlloc,

+** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and

+** xMutexNotheld) implement the following interfaces (respectively):

+**

+** <ul>

+**   <li>  [sqlite3_mutex_alloc()] </li>

+**   <li>  [sqlite3_mutex_free()] </li>

+**   <li>  [sqlite3_mutex_enter()] </li>

+**   <li>  [sqlite3_mutex_try()] </li>

+**   <li>  [sqlite3_mutex_leave()] </li>

+**   <li>  [sqlite3_mutex_held()] </li>

+**   <li>  [sqlite3_mutex_notheld()] </li>

+** </ul>

+**

+** The only difference is that the public sqlite3_XXX functions enumerated

+** above silently ignore any invocations that pass a NULL pointer instead

+** of a valid mutex handle. The implementations of the methods defined

+** by this structure are not required to handle this case, the results

+** of passing a NULL pointer instead of a valid mutex handle are undefined

+** (i.e. it is acceptable to provide an implementation that segfaults if

+** it is passed a NULL pointer).

+*/

+typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;

+struct sqlite3_mutex_methods {

+  int (*xMutexInit)(void);

+  int (*xMutexEnd)(void);

+  sqlite3_mutex *(*xMutexAlloc)(int);

+  void (*xMutexFree)(sqlite3_mutex *);

+  void (*xMutexEnter)(sqlite3_mutex *);

+  int (*xMutexTry)(sqlite3_mutex *);

+  void (*xMutexLeave)(sqlite3_mutex *);

+  int (*xMutexHeld)(sqlite3_mutex *);

+  int (*xMutexNotheld)(sqlite3_mutex *);

+};

+

+/*

+** CAPI3REF: Mutex Verification Routines {H17080} <S20130> <S30800>

+**

+** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines

+** are intended for use inside assert() statements. {H17081} The SQLite core

+** never uses these routines except inside an assert() and applications

+** are advised to follow the lead of the core.  {H17082} The core only

+** provides implementations for these routines when it is compiled

+** with the SQLITE_DEBUG flag.  {A17087} External mutex implementations

+** are only required to provide these routines if SQLITE_DEBUG is

+** defined and if NDEBUG is not defined.

+**

+** {H17083} These routines should return true if the mutex in their argument

+** is held or not held, respectively, by the calling thread.

+**

+** {X17084} The implementation is not required to provided versions of these

+** routines that actually work. If the implementation does not provide working

+** versions of these routines, it should at least provide stubs that always

+** return true so that one does not get spurious assertion failures.

+**

+** {H17085} If the argument to sqlite3_mutex_held() is a NULL pointer then

+** the routine should return 1.  {END} This seems counter-intuitive since

+** clearly the mutex cannot be held if it does not exist.  But the

+** the reason the mutex does not exist is because the build is not

+** using mutexes.  And we do not want the assert() containing the

+** call to sqlite3_mutex_held() to fail, so a non-zero return is

+** the appropriate thing to do.  {H17086} The sqlite3_mutex_notheld()

+** interface should also return 1 when given a NULL pointer.

+*/

+int sqlite3_mutex_held(sqlite3_mutex*);

+int sqlite3_mutex_notheld(sqlite3_mutex*);

+

+/*

+** CAPI3REF: Mutex Types {H17001} <H17000>

+**

+** The [sqlite3_mutex_alloc()] interface takes a single argument

+** which is one of these integer constants.

+**

+** The set of static mutexes may change from one SQLite release to the

+** next.  Applications that override the built-in mutex logic must be

+** prepared to accommodate additional static mutexes.

+*/

+#define SQLITE_MUTEX_FAST             0

+#define SQLITE_MUTEX_RECURSIVE        1

+#define SQLITE_MUTEX_STATIC_MASTER    2

+#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */

+#define SQLITE_MUTEX_STATIC_MEM2      4  /* sqlite3_release_memory() */

+#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */

+#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */

+#define SQLITE_MUTEX_STATIC_LRU2      7  /* lru page list */

+

+/*

+** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800>

+**

+** {H11301} The [sqlite3_file_control()] interface makes a direct call to the

+** xFileControl method for the [sqlite3_io_methods] object associated

+** with a particular database identified by the second argument. {H11302} The

+** name of the database is the name assigned to the database by the

+** <a href="lang_attach.html">ATTACH</a> SQL command that opened the

+** database. {H11303} To control the main database file, use the name "main"

+** or a NULL pointer. {H11304} The third and fourth parameters to this routine

+** are passed directly through to the second and third parameters of

+** the xFileControl method.  {H11305} The return value of the xFileControl

+** method becomes the return value of this routine.

+**

+** {H11306} If the second parameter (zDbName) does not match the name of any

+** open database file, then SQLITE_ERROR is returned. {H11307} This error

+** code is not remembered and will not be recalled by [sqlite3_errcode()]

+** or [sqlite3_errmsg()]. {A11308} The underlying xFileControl method might

+** also return SQLITE_ERROR.  {A11309} There is no way to distinguish between

+** an incorrect zDbName and an SQLITE_ERROR return from the underlying

+** xFileControl method. {END}

+**

+** See also: [SQLITE_FCNTL_LOCKSTATE]

+*/

+int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);

+

+/*

+** CAPI3REF: Testing Interface {H11400} <S30800>

+**

+** The sqlite3_test_control() interface is used to read out internal

+** state of SQLite and to inject faults into SQLite for testing

+** purposes.  The first parameter is an operation code that determines

+** the number, meaning, and operation of all subsequent parameters.

+**

+** This interface is not for use by applications.  It exists solely

+** for verifying the correct operation of the SQLite library.  Depending

+** on how the SQLite library is compiled, this interface might not exist.

+**

+** The details of the operation codes, their meanings, the parameters

+** they take, and what they do are all subject to change without notice.

+** Unlike most of the SQLite API, this function is not guaranteed to

+** operate consistently from one release to the next.

+*/

+int sqlite3_test_control(int op, ...);

+

+/*

+** CAPI3REF: Testing Interface Operation Codes {H11410} <H11400>

+**

+** These constants are the valid operation code parameters used

+** as the first argument to [sqlite3_test_control()].

+**

+** These parameters and their meanings are subject to change

+** without notice.  These values are for testing purposes only.

+** Applications should not use any of these parameters or the

+** [sqlite3_test_control()] interface.

+*/

+#define SQLITE_TESTCTRL_PRNG_SAVE                5

+#define SQLITE_TESTCTRL_PRNG_RESTORE             6

+#define SQLITE_TESTCTRL_PRNG_RESET               7

+#define SQLITE_TESTCTRL_BITVEC_TEST              8

+#define SQLITE_TESTCTRL_FAULT_INSTALL            9

+#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10

+

+/*

+** CAPI3REF: SQLite Runtime Status {H17200} <S60200>

+** EXPERIMENTAL

+**

+** This interface is used to retrieve runtime status information

+** about the preformance of SQLite, and optionally to reset various

+** highwater marks.  The first argument is an integer code for

+** the specific parameter to measure.  Recognized integer codes

+** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...].

+** The current value of the parameter is returned into *pCurrent.

+** The highest recorded value is returned in *pHighwater.  If the

+** resetFlag is true, then the highest record value is reset after

+** *pHighwater is written. Some parameters do not record the highest

+** value.  For those parameters

+** nothing is written into *pHighwater and the resetFlag is ignored.

+** Other parameters record only the highwater mark and not the current

+** value.  For these latter parameters nothing is written into *pCurrent.

+**

+** This routine returns SQLITE_OK on success and a non-zero

+** [error code] on failure.

+**

+** This routine is threadsafe but is not atomic.  This routine can

+** called while other threads are running the same or different SQLite

+** interfaces.  However the values returned in *pCurrent and

+** *pHighwater reflect the status of SQLite at different points in time

+** and it is possible that another thread might change the parameter

+** in between the times when *pCurrent and *pHighwater are written.

+**

+** See also: [sqlite3_db_status()]

+*/

+int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);

+

+/*

+** CAPI3REF: Database Connection Status {H17201} <S60200>

+** EXPERIMENTAL

+**

+** This interface is used to retrieve runtime status information 

+** about a single [database connection].  The first argument is the

+** database connection object to be interrogated.  The second argument

+** is the parameter to interrogate.  Currently, the only allowed value

+** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED].

+** Additional options will likely appear in future releases of SQLite.

+**

+** The current value of the request parameter is written into *pCur

+** and the highest instantaneous value is written into *pHiwtr.  If

+** the resetFlg is true, then the highest instantaneous value is

+** reset back down to the current value.

+**

+** See also: [sqlite3_status()].

+*/

+int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);

+

+/*

+** CAPI3REF: Status Parameters {H17250} <H17200>

+** EXPERIMENTAL

+**

+** These integer constants designate various run-time status parameters

+** that can be returned by [sqlite3_status()].

+**

+** <dl>

+** <dt>SQLITE_STATUS_MEMORY_USED</dt>

+** <dd>This parameter is the current amount of memory checked out

+** using [sqlite3_malloc()], either directly or indirectly.  The

+** figure includes calls made to [sqlite3_malloc()] by the application

+** and internal memory usage by the SQLite library.  Scratch memory

+** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache

+** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in

+** this parameter.  The amount returned is the sum of the allocation

+** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>

+**

+** <dt>SQLITE_STATUS_MALLOC_SIZE</dt>

+** <dd>This parameter records the largest memory allocation request

+** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their

+** internal equivalents).  Only the value returned in the

+** *pHighwater parameter to [sqlite3_status()] is of interest.  

+** The value written into the *pCurrent parameter is undefined.</dd>

+**

+** <dt>SQLITE_STATUS_PAGECACHE_USED</dt>

+** <dd>This parameter returns the number of pages used out of the

+** [pagecache memory allocator] that was configured using 

+** [SQLITE_CONFIG_PAGECACHE].  The

+** value returned is in pages, not in bytes.</dd>

+**

+** <dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>

+** <dd>This parameter returns the number of bytes of page cache

+** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE]

+** buffer and where forced to overflow to [sqlite3_malloc()].  The

+** returned value includes allocations that overflowed because they

+** where too large (they were larger than the "sz" parameter to

+** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because

+** no space was left in the page cache.</dd>

+**

+** <dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>

+** <dd>This parameter records the largest memory allocation request

+** handed to [pagecache memory allocator].  Only the value returned in the

+** *pHighwater parameter to [sqlite3_status()] is of interest.  

+** The value written into the *pCurrent parameter is undefined.</dd>

+**

+** <dt>SQLITE_STATUS_SCRATCH_USED</dt>

+** <dd>This parameter returns the number of allocations used out of the

+** [scratch memory allocator] configured using

+** [SQLITE_CONFIG_SCRATCH].  The value returned is in allocations, not

+** in bytes.  Since a single thread may only have one scratch allocation

+** outstanding at time, this parameter also reports the number of threads

+** using scratch memory at the same time.</dd>

+**

+** <dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>

+** <dd>This parameter returns the number of bytes of scratch memory

+** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH]

+** buffer and where forced to overflow to [sqlite3_malloc()].  The values

+** returned include overflows because the requested allocation was too

+** larger (that is, because the requested allocation was larger than the

+** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer

+** slots were available.

+** </dd>

+**

+** <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>

+** <dd>This parameter records the largest memory allocation request

+** handed to [scratch memory allocator].  Only the value returned in the

+** *pHighwater parameter to [sqlite3_status()] is of interest.  

+** The value written into the *pCurrent parameter is undefined.</dd>

+**

+** <dt>SQLITE_STATUS_PARSER_STACK</dt>

+** <dd>This parameter records the deepest parser stack.  It is only

+** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>

+** </dl>

+**

+** New status parameters may be added from time to time.

+*/

+#define SQLITE_STATUS_MEMORY_USED          0

+#define SQLITE_STATUS_PAGECACHE_USED       1

+#define SQLITE_STATUS_PAGECACHE_OVERFLOW   2

+#define SQLITE_STATUS_SCRATCH_USED         3

+#define SQLITE_STATUS_SCRATCH_OVERFLOW     4

+#define SQLITE_STATUS_MALLOC_SIZE          5

+#define SQLITE_STATUS_PARSER_STACK         6

+#define SQLITE_STATUS_PAGECACHE_SIZE       7

+#define SQLITE_STATUS_SCRATCH_SIZE         8

+

+/*

+** CAPI3REF: Status Parameters for database connections {H17275} <H17200>

+** EXPERIMENTAL

+**

+** Status verbs for [sqlite3_db_status()].

+**

+** <dl>

+** <dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>

+** <dd>This parameter returns the number of lookaside memory slots currently

+** checked out.</dd>

+** </dl>

+*/

+#define SQLITE_DBSTATUS_LOOKASIDE_USED     0

+

+/*

+** Undo the hack that converts floating point types to integer for

+** builds on processors without floating point support.

+*/

+#ifdef SQLITE_OMIT_FLOATING_POINT

+# undef double

+#endif

+

+#ifdef __cplusplus

+}  /* End of the 'extern "C"' block */

+#endif

+#endif

diff --git a/third_party/sqlite/src/sqlite3ext.h b/third_party/sqlite/src/sqlite3ext.h
new file mode 100755
index 0000000..a4da1d9
--- /dev/null
+++ b/third_party/sqlite/src/sqlite3ext.h
@@ -0,0 +1,378 @@
+/*
+** 2006 June 7
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This header file defines the SQLite interface for use by
+** shared libraries that want to be imported as extensions into
+** an SQLite instance.  Shared libraries that intend to be loaded
+** as extensions by SQLite should #include this file instead of 
+** sqlite3.h.
+**
+** @(#) $Id: sqlite3ext.h,v 1.24 2008/06/30 15:09:29 danielk1977 Exp $
+*/
+#ifndef _SQLITE3EXT_H_
+#define _SQLITE3EXT_H_
+#include "sqlite3.h"
+
+typedef struct sqlite3_api_routines sqlite3_api_routines;
+
+/*
+** The following structure holds pointers to all of the SQLite API
+** routines.
+**
+** WARNING:  In order to maintain backwards compatibility, add new
+** interfaces to the end of this structure only.  If you insert new
+** interfaces in the middle of this structure, then older different
+** versions of SQLite will not be able to load each others' shared
+** libraries!
+*/
+struct sqlite3_api_routines {
+  void * (*aggregate_context)(sqlite3_context*,int nBytes);
+  int  (*aggregate_count)(sqlite3_context*);
+  int  (*bind_blob)(sqlite3_stmt*,int,const void*,int n,void(*)(void*));
+  int  (*bind_double)(sqlite3_stmt*,int,double);
+  int  (*bind_int)(sqlite3_stmt*,int,int);
+  int  (*bind_int64)(sqlite3_stmt*,int,sqlite_int64);
+  int  (*bind_null)(sqlite3_stmt*,int);
+  int  (*bind_parameter_count)(sqlite3_stmt*);
+  int  (*bind_parameter_index)(sqlite3_stmt*,const char*zName);
+  const char * (*bind_parameter_name)(sqlite3_stmt*,int);
+  int  (*bind_text)(sqlite3_stmt*,int,const char*,int n,void(*)(void*));
+  int  (*bind_text16)(sqlite3_stmt*,int,const void*,int,void(*)(void*));
+  int  (*bind_value)(sqlite3_stmt*,int,const sqlite3_value*);
+  int  (*busy_handler)(sqlite3*,int(*)(void*,int),void*);
+  int  (*busy_timeout)(sqlite3*,int ms);
+  int  (*changes)(sqlite3*);
+  int  (*close)(sqlite3*);
+  int  (*collation_needed)(sqlite3*,void*,void(*)(void*,sqlite3*,int eTextRep,const char*));
+  int  (*collation_needed16)(sqlite3*,void*,void(*)(void*,sqlite3*,int eTextRep,const void*));
+  const void * (*column_blob)(sqlite3_stmt*,int iCol);
+  int  (*column_bytes)(sqlite3_stmt*,int iCol);
+  int  (*column_bytes16)(sqlite3_stmt*,int iCol);
+  int  (*column_count)(sqlite3_stmt*pStmt);
+  const char * (*column_database_name)(sqlite3_stmt*,int);
+  const void * (*column_database_name16)(sqlite3_stmt*,int);
+  const char * (*column_decltype)(sqlite3_stmt*,int i);
+  const void * (*column_decltype16)(sqlite3_stmt*,int);
+  double  (*column_double)(sqlite3_stmt*,int iCol);
+  int  (*column_int)(sqlite3_stmt*,int iCol);
+  sqlite_int64  (*column_int64)(sqlite3_stmt*,int iCol);
+  const char * (*column_name)(sqlite3_stmt*,int);
+  const void * (*column_name16)(sqlite3_stmt*,int);
+  const char * (*column_origin_name)(sqlite3_stmt*,int);
+  const void * (*column_origin_name16)(sqlite3_stmt*,int);
+  const char * (*column_table_name)(sqlite3_stmt*,int);
+  const void * (*column_table_name16)(sqlite3_stmt*,int);
+  const unsigned char * (*column_text)(sqlite3_stmt*,int iCol);
+  const void * (*column_text16)(sqlite3_stmt*,int iCol);
+  int  (*column_type)(sqlite3_stmt*,int iCol);
+  sqlite3_value* (*column_value)(sqlite3_stmt*,int iCol);
+  void * (*commit_hook)(sqlite3*,int(*)(void*),void*);
+  int  (*complete)(const char*sql);
+  int  (*complete16)(const void*sql);
+  int  (*create_collation)(sqlite3*,const char*,int,void*,int(*)(void*,int,const void*,int,const void*));
+  int  (*create_collation16)(sqlite3*,const void*,int,void*,int(*)(void*,int,const void*,int,const void*));
+  int  (*create_function)(sqlite3*,const char*,int,int,void*,void (*xFunc)(sqlite3_context*,int,sqlite3_value**),void (*xStep)(sqlite3_context*,int,sqlite3_value**),void (*xFinal)(sqlite3_context*));
+  int  (*create_function16)(sqlite3*,const void*,int,int,void*,void (*xFunc)(sqlite3_context*,int,sqlite3_value**),void (*xStep)(sqlite3_context*,int,sqlite3_value**),void (*xFinal)(sqlite3_context*));
+  int (*create_module)(sqlite3*,const char*,const sqlite3_module*,void*);
+  int  (*data_count)(sqlite3_stmt*pStmt);
+  sqlite3 * (*db_handle)(sqlite3_stmt*);
+  int (*declare_vtab)(sqlite3*,const char*);
+  int  (*enable_shared_cache)(int);
+  int  (*errcode)(sqlite3*db);
+  const char * (*errmsg)(sqlite3*);
+  const void * (*errmsg16)(sqlite3*);
+  int  (*exec)(sqlite3*,const char*,sqlite3_callback,void*,char**);
+  int  (*expired)(sqlite3_stmt*);
+  int  (*finalize)(sqlite3_stmt*pStmt);
+  void  (*free)(void*);
+  void  (*free_table)(char**result);
+  int  (*get_autocommit)(sqlite3*);
+  void * (*get_auxdata)(sqlite3_context*,int);
+  int  (*get_table)(sqlite3*,const char*,char***,int*,int*,char**);
+  int  (*global_recover)(void);
+  void  (*interruptx)(sqlite3*);
+  sqlite_int64  (*last_insert_rowid)(sqlite3*);
+  const char * (*libversion)(void);
+  int  (*libversion_number)(void);
+  void *(*malloc)(int);
+  char * (*mprintf)(const char*,...);
+  int  (*open)(const char*,sqlite3**);
+  int  (*open16)(const void*,sqlite3**);
+  int  (*prepare)(sqlite3*,const char*,int,sqlite3_stmt**,const char**);
+  int  (*prepare16)(sqlite3*,const void*,int,sqlite3_stmt**,const void**);
+  void * (*profile)(sqlite3*,void(*)(void*,const char*,sqlite_uint64),void*);
+  void  (*progress_handler)(sqlite3*,int,int(*)(void*),void*);
+  void *(*realloc)(void*,int);
+  int  (*reset)(sqlite3_stmt*pStmt);
+  void  (*result_blob)(sqlite3_context*,const void*,int,void(*)(void*));
+  void  (*result_double)(sqlite3_context*,double);
+  void  (*result_error)(sqlite3_context*,const char*,int);
+  void  (*result_error16)(sqlite3_context*,const void*,int);
+  void  (*result_int)(sqlite3_context*,int);
+  void  (*result_int64)(sqlite3_context*,sqlite_int64);
+  void  (*result_null)(sqlite3_context*);
+  void  (*result_text)(sqlite3_context*,const char*,int,void(*)(void*));
+  void  (*result_text16)(sqlite3_context*,const void*,int,void(*)(void*));
+  void  (*result_text16be)(sqlite3_context*,const void*,int,void(*)(void*));
+  void  (*result_text16le)(sqlite3_context*,const void*,int,void(*)(void*));
+  void  (*result_value)(sqlite3_context*,sqlite3_value*);
+  void * (*rollback_hook)(sqlite3*,void(*)(void*),void*);
+  int  (*set_authorizer)(sqlite3*,int(*)(void*,int,const char*,const char*,const char*,const char*),void*);
+  void  (*set_auxdata)(sqlite3_context*,int,void*,void (*)(void*));
+  char * (*snprintf)(int,char*,const char*,...);
+  int  (*step)(sqlite3_stmt*);
+  int  (*table_column_metadata)(sqlite3*,const char*,const char*,const char*,char const**,char const**,int*,int*,int*);
+  void  (*thread_cleanup)(void);
+  int  (*total_changes)(sqlite3*);
+  void * (*trace)(sqlite3*,void(*xTrace)(void*,const char*),void*);
+  int  (*transfer_bindings)(sqlite3_stmt*,sqlite3_stmt*);
+  void * (*update_hook)(sqlite3*,void(*)(void*,int ,char const*,char const*,sqlite_int64),void*);
+  void * (*user_data)(sqlite3_context*);
+  const void * (*value_blob)(sqlite3_value*);
+  int  (*value_bytes)(sqlite3_value*);
+  int  (*value_bytes16)(sqlite3_value*);
+  double  (*value_double)(sqlite3_value*);
+  int  (*value_int)(sqlite3_value*);
+  sqlite_int64  (*value_int64)(sqlite3_value*);
+  int  (*value_numeric_type)(sqlite3_value*);
+  const unsigned char * (*value_text)(sqlite3_value*);
+  const void * (*value_text16)(sqlite3_value*);
+  const void * (*value_text16be)(sqlite3_value*);
+  const void * (*value_text16le)(sqlite3_value*);
+  int  (*value_type)(sqlite3_value*);
+  char *(*vmprintf)(const char*,va_list);
+  /* Added ??? */
+  int (*overload_function)(sqlite3*, const char *zFuncName, int nArg);
+  /* Added by 3.3.13 */
+  int (*prepare_v2)(sqlite3*,const char*,int,sqlite3_stmt**,const char**);
+  int (*prepare16_v2)(sqlite3*,const void*,int,sqlite3_stmt**,const void**);
+  int (*clear_bindings)(sqlite3_stmt*);
+  /* Added by 3.4.1 */
+  int (*create_module_v2)(sqlite3*,const char*,const sqlite3_module*,void*,void (*xDestroy)(void *));
+  /* Added by 3.5.0 */
+  int (*bind_zeroblob)(sqlite3_stmt*,int,int);
+  int (*blob_bytes)(sqlite3_blob*);
+  int (*blob_close)(sqlite3_blob*);
+  int (*blob_open)(sqlite3*,const char*,const char*,const char*,sqlite3_int64,int,sqlite3_blob**);
+  int (*blob_read)(sqlite3_blob*,void*,int,int);
+  int (*blob_write)(sqlite3_blob*,const void*,int,int);
+  int (*create_collation_v2)(sqlite3*,const char*,int,void*,int(*)(void*,int,const void*,int,const void*),void(*)(void*));
+  int (*file_control)(sqlite3*,const char*,int,void*);
+  sqlite3_int64 (*memory_highwater)(int);
+  sqlite3_int64 (*memory_used)(void);
+  sqlite3_mutex *(*mutex_alloc)(int);
+  void (*mutex_enter)(sqlite3_mutex*);
+  void (*mutex_free)(sqlite3_mutex*);
+  void (*mutex_leave)(sqlite3_mutex*);
+  int (*mutex_try)(sqlite3_mutex*);
+  int (*open_v2)(const char*,sqlite3**,int,const char*);
+  int (*release_memory)(int);
+  void (*result_error_nomem)(sqlite3_context*);
+  void (*result_error_toobig)(sqlite3_context*);
+  int (*sleep)(int);
+  void (*soft_heap_limit)(int);
+  sqlite3_vfs *(*vfs_find)(const char*);
+  int (*vfs_register)(sqlite3_vfs*,int);
+  int (*vfs_unregister)(sqlite3_vfs*);
+  int (*xthreadsafe)(void);
+  void (*result_zeroblob)(sqlite3_context*,int);
+  void (*result_error_code)(sqlite3_context*,int);
+  int (*test_control)(int, ...);
+  void (*randomness)(int,void*);
+  sqlite3 *(*context_db_handle)(sqlite3_context*);
+  int (*extended_result_codes)(sqlite3*,int);
+  int (*limit)(sqlite3*,int,int);
+  sqlite3_stmt *(*next_stmt)(sqlite3*,sqlite3_stmt*);
+  const char *(*sql)(sqlite3_stmt*);
+  int (*status)(int,int*,int*,int);
+};
+
+/*
+** The following macros redefine the API routines so that they are
+** redirected throught the global sqlite3_api structure.
+**
+** This header file is also used by the loadext.c source file
+** (part of the main SQLite library - not an extension) so that
+** it can get access to the sqlite3_api_routines structure
+** definition.  But the main library does not want to redefine
+** the API.  So the redefinition macros are only valid if the
+** SQLITE_CORE macros is undefined.
+*/
+#ifndef SQLITE_CORE
+#define sqlite3_aggregate_context      sqlite3_api->aggregate_context
+#define sqlite3_aggregate_count        sqlite3_api->aggregate_count
+#define sqlite3_bind_blob              sqlite3_api->bind_blob
+#define sqlite3_bind_double            sqlite3_api->bind_double
+#define sqlite3_bind_int               sqlite3_api->bind_int
+#define sqlite3_bind_int64             sqlite3_api->bind_int64
+#define sqlite3_bind_null              sqlite3_api->bind_null
+#define sqlite3_bind_parameter_count   sqlite3_api->bind_parameter_count
+#define sqlite3_bind_parameter_index   sqlite3_api->bind_parameter_index
+#define sqlite3_bind_parameter_name    sqlite3_api->bind_parameter_name
+#define sqlite3_bind_text              sqlite3_api->bind_text
+#define sqlite3_bind_text16            sqlite3_api->bind_text16
+#define sqlite3_bind_value             sqlite3_api->bind_value
+#define sqlite3_busy_handler           sqlite3_api->busy_handler
+#define sqlite3_busy_timeout           sqlite3_api->busy_timeout
+#define sqlite3_changes                sqlite3_api->changes
+#define sqlite3_close                  sqlite3_api->close
+#define sqlite3_collation_needed       sqlite3_api->collation_needed
+#define sqlite3_collation_needed16     sqlite3_api->collation_needed16
+#define sqlite3_column_blob            sqlite3_api->column_blob
+#define sqlite3_column_bytes           sqlite3_api->column_bytes
+#define sqlite3_column_bytes16         sqlite3_api->column_bytes16
+#define sqlite3_column_count           sqlite3_api->column_count
+#define sqlite3_column_database_name   sqlite3_api->column_database_name
+#define sqlite3_column_database_name16 sqlite3_api->column_database_name16
+#define sqlite3_column_decltype        sqlite3_api->column_decltype
+#define sqlite3_column_decltype16      sqlite3_api->column_decltype16
+#define sqlite3_column_double          sqlite3_api->column_double
+#define sqlite3_column_int             sqlite3_api->column_int
+#define sqlite3_column_int64           sqlite3_api->column_int64
+#define sqlite3_column_name            sqlite3_api->column_name
+#define sqlite3_column_name16          sqlite3_api->column_name16
+#define sqlite3_column_origin_name     sqlite3_api->column_origin_name
+#define sqlite3_column_origin_name16   sqlite3_api->column_origin_name16
+#define sqlite3_column_table_name      sqlite3_api->column_table_name
+#define sqlite3_column_table_name16    sqlite3_api->column_table_name16
+#define sqlite3_column_text            sqlite3_api->column_text
+#define sqlite3_column_text16          sqlite3_api->column_text16
+#define sqlite3_column_type            sqlite3_api->column_type
+#define sqlite3_column_value           sqlite3_api->column_value
+#define sqlite3_commit_hook            sqlite3_api->commit_hook
+#define sqlite3_complete               sqlite3_api->complete
+#define sqlite3_complete16             sqlite3_api->complete16
+#define sqlite3_create_collation       sqlite3_api->create_collation
+#define sqlite3_create_collation16     sqlite3_api->create_collation16
+#define sqlite3_create_function        sqlite3_api->create_function
+#define sqlite3_create_function16      sqlite3_api->create_function16
+#define sqlite3_create_module          sqlite3_api->create_module
+#define sqlite3_create_module_v2       sqlite3_api->create_module_v2
+#define sqlite3_data_count             sqlite3_api->data_count
+#define sqlite3_db_handle              sqlite3_api->db_handle
+#define sqlite3_declare_vtab           sqlite3_api->declare_vtab
+#define sqlite3_enable_shared_cache    sqlite3_api->enable_shared_cache
+#define sqlite3_errcode                sqlite3_api->errcode
+#define sqlite3_errmsg                 sqlite3_api->errmsg
+#define sqlite3_errmsg16               sqlite3_api->errmsg16
+#define sqlite3_exec                   sqlite3_api->exec
+#define sqlite3_expired                sqlite3_api->expired
+#define sqlite3_finalize               sqlite3_api->finalize
+#define sqlite3_free                   sqlite3_api->free
+#define sqlite3_free_table             sqlite3_api->free_table
+#define sqlite3_get_autocommit         sqlite3_api->get_autocommit
+#define sqlite3_get_auxdata            sqlite3_api->get_auxdata
+#define sqlite3_get_table              sqlite3_api->get_table
+#define sqlite3_global_recover         sqlite3_api->global_recover
+#define sqlite3_interrupt              sqlite3_api->interruptx
+#define sqlite3_last_insert_rowid      sqlite3_api->last_insert_rowid
+#define sqlite3_libversion             sqlite3_api->libversion
+#define sqlite3_libversion_number      sqlite3_api->libversion_number
+#define sqlite3_malloc                 sqlite3_api->malloc
+#define sqlite3_mprintf                sqlite3_api->mprintf
+#define sqlite3_open                   sqlite3_api->open
+#define sqlite3_open16                 sqlite3_api->open16
+#define sqlite3_prepare                sqlite3_api->prepare
+#define sqlite3_prepare16              sqlite3_api->prepare16
+#define sqlite3_prepare_v2             sqlite3_api->prepare_v2
+#define sqlite3_prepare16_v2           sqlite3_api->prepare16_v2
+#define sqlite3_profile                sqlite3_api->profile
+#define sqlite3_progress_handler       sqlite3_api->progress_handler
+#define sqlite3_realloc                sqlite3_api->realloc
+#define sqlite3_reset                  sqlite3_api->reset
+#define sqlite3_result_blob            sqlite3_api->result_blob
+#define sqlite3_result_double          sqlite3_api->result_double
+#define sqlite3_result_error           sqlite3_api->result_error
+#define sqlite3_result_error16         sqlite3_api->result_error16
+#define sqlite3_result_int             sqlite3_api->result_int
+#define sqlite3_result_int64           sqlite3_api->result_int64
+#define sqlite3_result_null            sqlite3_api->result_null
+#define sqlite3_result_text            sqlite3_api->result_text
+#define sqlite3_result_text16          sqlite3_api->result_text16
+#define sqlite3_result_text16be        sqlite3_api->result_text16be
+#define sqlite3_result_text16le        sqlite3_api->result_text16le
+#define sqlite3_result_value           sqlite3_api->result_value
+#define sqlite3_rollback_hook          sqlite3_api->rollback_hook
+#define sqlite3_set_authorizer         sqlite3_api->set_authorizer
+#define sqlite3_set_auxdata            sqlite3_api->set_auxdata
+#define sqlite3_snprintf               sqlite3_api->snprintf
+#define sqlite3_step                   sqlite3_api->step
+#define sqlite3_table_column_metadata  sqlite3_api->table_column_metadata
+#define sqlite3_thread_cleanup         sqlite3_api->thread_cleanup
+#define sqlite3_total_changes          sqlite3_api->total_changes
+#define sqlite3_trace                  sqlite3_api->trace
+#define sqlite3_transfer_bindings      sqlite3_api->transfer_bindings
+#define sqlite3_update_hook            sqlite3_api->update_hook
+#define sqlite3_user_data              sqlite3_api->user_data
+#define sqlite3_value_blob             sqlite3_api->value_blob
+#define sqlite3_value_bytes            sqlite3_api->value_bytes
+#define sqlite3_value_bytes16          sqlite3_api->value_bytes16
+#define sqlite3_value_double           sqlite3_api->value_double
+#define sqlite3_value_int              sqlite3_api->value_int
+#define sqlite3_value_int64            sqlite3_api->value_int64
+#define sqlite3_value_numeric_type     sqlite3_api->value_numeric_type
+#define sqlite3_value_text             sqlite3_api->value_text
+#define sqlite3_value_text16           sqlite3_api->value_text16
+#define sqlite3_value_text16be         sqlite3_api->value_text16be
+#define sqlite3_value_text16le         sqlite3_api->value_text16le
+#define sqlite3_value_type             sqlite3_api->value_type
+#define sqlite3_vmprintf               sqlite3_api->vmprintf
+#define sqlite3_overload_function      sqlite3_api->overload_function
+#define sqlite3_prepare_v2             sqlite3_api->prepare_v2
+#define sqlite3_prepare16_v2           sqlite3_api->prepare16_v2
+#define sqlite3_clear_bindings         sqlite3_api->clear_bindings
+#define sqlite3_bind_zeroblob          sqlite3_api->bind_zeroblob
+#define sqlite3_blob_bytes             sqlite3_api->blob_bytes
+#define sqlite3_blob_close             sqlite3_api->blob_close
+#define sqlite3_blob_open              sqlite3_api->blob_open
+#define sqlite3_blob_read              sqlite3_api->blob_read
+#define sqlite3_blob_write             sqlite3_api->blob_write
+#define sqlite3_create_collation_v2    sqlite3_api->create_collation_v2
+#define sqlite3_file_control           sqlite3_api->file_control
+#define sqlite3_memory_highwater       sqlite3_api->memory_highwater
+#define sqlite3_memory_used            sqlite3_api->memory_used
+#define sqlite3_mutex_alloc            sqlite3_api->mutex_alloc
+#define sqlite3_mutex_enter            sqlite3_api->mutex_enter
+#define sqlite3_mutex_free             sqlite3_api->mutex_free
+#define sqlite3_mutex_leave            sqlite3_api->mutex_leave
+#define sqlite3_mutex_try              sqlite3_api->mutex_try
+#define sqlite3_open_v2                sqlite3_api->open_v2
+#define sqlite3_release_memory         sqlite3_api->release_memory
+#define sqlite3_result_error_nomem     sqlite3_api->result_error_nomem
+#define sqlite3_result_error_toobig    sqlite3_api->result_error_toobig
+#define sqlite3_sleep                  sqlite3_api->sleep
+#define sqlite3_soft_heap_limit        sqlite3_api->soft_heap_limit
+#define sqlite3_vfs_find               sqlite3_api->vfs_find
+#define sqlite3_vfs_register           sqlite3_api->vfs_register
+#define sqlite3_vfs_unregister         sqlite3_api->vfs_unregister
+#define sqlite3_threadsafe             sqlite3_api->xthreadsafe
+#define sqlite3_result_zeroblob        sqlite3_api->result_zeroblob
+#define sqlite3_result_error_code      sqlite3_api->result_error_code
+#define sqlite3_test_control           sqlite3_api->test_control
+#define sqlite3_randomness             sqlite3_api->randomness
+#define sqlite3_context_db_handle      sqlite3_api->context_db_handle
+#define sqlite3_extended_result_codes  sqlite3_api->extended_result_codes
+#define sqlite3_limit                  sqlite3_api->limit
+#define sqlite3_next_stmt              sqlite3_api->next_stmt
+#define sqlite3_sql                    sqlite3_api->sql
+#define sqlite3_status                 sqlite3_api->status
+
+#define SQLITE_EXTENSION_INIT1     const sqlite3_api_routines *sqlite3_api = 0;
+#define SQLITE_EXTENSION_INIT2(v)  sqlite3_api = v;
+
+#else
+
+#define SQLITE_EXTENSION_INIT1
+#define SQLITE_EXTENSION_INIT2(v)
+
+#endif /* SQLITE_CORE */
+
+#endif /* _SQLITE3EXT_H_ */
diff --git a/third_party/sqlite/src/sqliteInt.h b/third_party/sqlite/src/sqliteInt.h
new file mode 100755
index 0000000..68de4a1
--- /dev/null
+++ b/third_party/sqlite/src/sqliteInt.h
@@ -0,0 +1,2357 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Internal interface definitions for SQLite.
+**
+** @(#) $Id: sqliteInt.h,v 1.752 2008/08/04 20:13:27 drh Exp $
+*/
+#ifndef _SQLITEINT_H_
+#define _SQLITEINT_H_
+
+/*
+** Include the configuration header output by 'configure' if we're using the
+** autoconf-based build
+*/
+#ifdef _HAVE_SQLITE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "sqliteLimit.h"
+
+/* Disable nuisance warnings on Borland compilers */
+#if defined(__BORLANDC__)
+#pragma warn -rch /* unreachable code */
+#pragma warn -ccc /* Condition is always true or false */
+#pragma warn -aus /* Assigned value is never used */
+#pragma warn -csu /* Comparing signed and unsigned */
+#pragma warn -spa /* Suspicous pointer arithmetic */
+#endif
+
+/* Needed for various definitions... */
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
+
+/*
+** Include standard header files as necessary
+*/
+#ifdef HAVE_STDINT_H
+#include <stdint.h>
+#endif
+#ifdef HAVE_INTTYPES_H
+#include <inttypes.h>
+#endif
+
+/*
+** A macro used to aid in coverage testing.  When doing coverage
+** testing, the condition inside the argument must be evaluated 
+** both true and false in order to get full branch coverage.
+** This macro can be inserted to ensure adequate test coverage
+** in places where simple condition/decision coverage is inadequate.
+*/
+#ifdef SQLITE_COVERAGE_TEST
+  void sqlite3Coverage(int);
+# define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
+#else
+# define testcase(X)
+#endif
+
+/*
+** The ALWAYS and NEVER macros surround boolean expressions which 
+** are intended to always be true or false, respectively.  Such
+** expressions could be omitted from the code completely.  But they
+** are included in a few cases in order to enhance the resilience
+** of SQLite to unexpected behavior - to make the code "self-healing"
+** or "ductile" rather than being "brittle" and crashing at the first
+** hint of unplanned behavior.
+**
+** When doing coverage testing ALWAYS and NEVER are hard-coded to
+** be true and false so that the unreachable code then specify will
+** not be counted as untested code.
+*/
+#ifdef SQLITE_COVERAGE_TEST
+# define ALWAYS(X)      (1)
+# define NEVER(X)       (0)
+#else
+# define ALWAYS(X)      (X)
+# define NEVER(X)       (X)
+#endif
+
+/*
+** The macro unlikely() is a hint that surrounds a boolean
+** expression that is usually false.  Macro likely() surrounds
+** a boolean expression that is usually true.  GCC is able to
+** use these hints to generate better code, sometimes.
+*/
+#if defined(__GNUC__) && 0
+# define likely(X)    __builtin_expect((X),1)
+# define unlikely(X)  __builtin_expect((X),0)
+#else
+# define likely(X)    !!(X)
+# define unlikely(X)  !!(X)
+#endif
+
+/*
+ * This macro is used to "hide" some ugliness in casting an int
+ * value to a ptr value under the MSVC 64-bit compiler.   Casting
+ * non 64-bit values to ptr types results in a "hard" error with 
+ * the MSVC 64-bit compiler which this attempts to avoid.  
+ *
+ * A simple compiler pragma or casting sequence could not be found
+ * to correct this in all situations, so this macro was introduced.
+ *
+ * It could be argued that the intptr_t type could be used in this
+ * case, but that type is not available on all compilers, or 
+ * requires the #include of specific headers which differs between
+ * platforms.
+ */
+#define SQLITE_INT_TO_PTR(X)   ((void*)&((char*)0)[X])
+#define SQLITE_PTR_TO_INT(X)   ((int)(((char*)X)-(char*)0))
+
+/*
+** These #defines should enable >2GB file support on Posix if the
+** underlying operating system supports it.  If the OS lacks
+** large file support, or if the OS is windows, these should be no-ops.
+**
+** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
+** system #includes.  Hence, this block of code must be the very first
+** code in all source files.
+**
+** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
+** on the compiler command line.  This is necessary if you are compiling
+** on a recent machine (ex: RedHat 7.2) but you want your code to work
+** on an older machine (ex: RedHat 6.0).  If you compile on RedHat 7.2
+** without this option, LFS is enable.  But LFS does not exist in the kernel
+** in RedHat 6.0, so the code won't work.  Hence, for maximum binary
+** portability you should omit LFS.
+**
+** Similar is true for MacOS.  LFS is only supported on MacOS 9 and later.
+*/
+#ifndef SQLITE_DISABLE_LFS
+# define _LARGE_FILE       1
+# ifndef _FILE_OFFSET_BITS
+#   define _FILE_OFFSET_BITS 64
+# endif
+# define _LARGEFILE_SOURCE 1
+#endif
+
+
+/*
+** The SQLITE_THREADSAFE macro must be defined as either 0 or 1.
+** Older versions of SQLite used an optional THREADSAFE macro.
+** We support that for legacy
+*/
+#if !defined(SQLITE_THREADSAFE)
+#if defined(THREADSAFE)
+# define SQLITE_THREADSAFE THREADSAFE
+#else
+# define SQLITE_THREADSAFE 1
+#endif
+#endif
+
+/*
+** Exactly one of the following macros must be defined in order to
+** specify which memory allocation subsystem to use.
+**
+**     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
+**     SQLITE_MEMDEBUG               // Debugging version of system malloc()
+**     SQLITE_MEMORY_SIZE            // internal allocator #1
+**     SQLITE_MMAP_HEAP_SIZE         // internal mmap() allocator
+**     SQLITE_POW2_MEMORY_SIZE       // internal power-of-two allocator
+**
+** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
+** the default.
+*/
+#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
+    defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
+    defined(SQLITE_POW2_MEMORY_SIZE)>1
+# error "At most one of the following compile-time configuration options\
+ is allows: SQLITE_SYSTEM_MALLOC, SQLITE_MEMDEBUG, SQLITE_MEMORY_SIZE,\
+ SQLITE_MMAP_HEAP_SIZE, SQLITE_POW2_MEMORY_SIZE"
+#endif
+#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
+    defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
+    defined(SQLITE_POW2_MEMORY_SIZE)==0
+# define SQLITE_SYSTEM_MALLOC 1
+#endif
+
+/*
+** If SQLITE_MALLOC_SOFT_LIMIT is defined, then try to keep the
+** sizes of memory allocations below this value where possible.
+*/
+#if defined(SQLITE_POW2_MEMORY_SIZE) && !defined(SQLITE_MALLOC_SOFT_LIMIT)
+# define SQLITE_MALLOC_SOFT_LIMIT 1024
+#endif
+
+/*
+** We need to define _XOPEN_SOURCE as follows in order to enable
+** recursive mutexes on most unix systems.  But Mac OS X is different.
+** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
+** so it is omitted there.  See ticket #2673.
+**
+** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
+** implemented on some systems.  So we avoid defining it at all
+** if it is already defined or if it is unneeded because we are
+** not doing a threadsafe build.  Ticket #2681.
+**
+** See also ticket #2741.
+*/
+#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
+#  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
+#endif
+
+#if defined(SQLITE_TCL) || defined(TCLSH)
+# include <tcl.h>
+#endif
+
+/*
+** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
+** Setting NDEBUG makes the code smaller and run faster.  So the following
+** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
+** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
+** feature.
+*/
+#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
+# define NDEBUG 1
+#endif
+
+#include "sqlite3.h"
+#include "hash.h"
+#include "parse.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <stddef.h>
+
+/*
+** If compiling for a processor that lacks floating point support,
+** substitute integer for floating-point
+*/
+#ifdef SQLITE_OMIT_FLOATING_POINT
+# define double sqlite_int64
+# define LONGDOUBLE_TYPE sqlite_int64
+# ifndef SQLITE_BIG_DBL
+#   define SQLITE_BIG_DBL (0x7fffffffffffffff)
+# endif
+# define SQLITE_OMIT_DATETIME_FUNCS 1
+# define SQLITE_OMIT_TRACE 1
+# undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
+#endif
+#ifndef SQLITE_BIG_DBL
+# define SQLITE_BIG_DBL (1e99)
+#endif
+
+/*
+** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
+** afterward. Having this macro allows us to cause the C compiler 
+** to omit code used by TEMP tables without messy #ifndef statements.
+*/
+#ifdef SQLITE_OMIT_TEMPDB
+#define OMIT_TEMPDB 1
+#else
+#define OMIT_TEMPDB 0
+#endif
+
+/*
+** If the following macro is set to 1, then NULL values are considered
+** distinct when determining whether or not two entries are the same
+** in a UNIQUE index.  This is the way PostgreSQL, Oracle, DB2, MySQL,
+** OCELOT, and Firebird all work.  The SQL92 spec explicitly says this
+** is the way things are suppose to work.
+**
+** If the following macro is set to 0, the NULLs are indistinct for
+** a UNIQUE index.  In this mode, you can only have a single NULL entry
+** for a column declared UNIQUE.  This is the way Informix and SQL Server
+** work.
+*/
+#define NULL_DISTINCT_FOR_UNIQUE 1
+
+/*
+** The "file format" number is an integer that is incremented whenever
+** the VDBE-level file format changes.  The following macros define the
+** the default file format for new databases and the maximum file format
+** that the library can read.
+*/
+#define SQLITE_MAX_FILE_FORMAT 4
+#ifndef SQLITE_DEFAULT_FILE_FORMAT
+# define SQLITE_DEFAULT_FILE_FORMAT 1
+#endif
+
+/*
+** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
+** on the command-line
+*/
+#ifndef SQLITE_TEMP_STORE
+# define SQLITE_TEMP_STORE 1
+#endif
+
+/*
+** GCC does not define the offsetof() macro so we'll have to do it
+** ourselves.
+*/
+#ifndef offsetof
+#define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
+#endif
+
+/*
+** Check to see if this machine uses EBCDIC.  (Yes, believe it or
+** not, there are still machines out there that use EBCDIC.)
+*/
+#if 'A' == '\301'
+# define SQLITE_EBCDIC 1
+#else
+# define SQLITE_ASCII 1
+#endif
+
+/*
+** Integers of known sizes.  These typedefs might change for architectures
+** where the sizes very.  Preprocessor macros are available so that the
+** types can be conveniently redefined at compile-type.  Like this:
+**
+**         cc '-DUINTPTR_TYPE=long long int' ...
+*/
+#ifndef UINT32_TYPE
+# ifdef HAVE_UINT32_T
+#  define UINT32_TYPE uint32_t
+# else
+#  define UINT32_TYPE unsigned int
+# endif
+#endif
+#ifndef UINT16_TYPE
+# ifdef HAVE_UINT16_T
+#  define UINT16_TYPE uint16_t
+# else
+#  define UINT16_TYPE unsigned short int
+# endif
+#endif
+#ifndef INT16_TYPE
+# ifdef HAVE_INT16_T
+#  define INT16_TYPE int16_t
+# else
+#  define INT16_TYPE short int
+# endif
+#endif
+#ifndef UINT8_TYPE
+# ifdef HAVE_UINT8_T
+#  define UINT8_TYPE uint8_t
+# else
+#  define UINT8_TYPE unsigned char
+# endif
+#endif
+#ifndef INT8_TYPE
+# ifdef HAVE_INT8_T
+#  define INT8_TYPE int8_t
+# else
+#  define INT8_TYPE signed char
+# endif
+#endif
+#ifndef LONGDOUBLE_TYPE
+# define LONGDOUBLE_TYPE long double
+#endif
+typedef sqlite_int64 i64;          /* 8-byte signed integer */
+typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
+typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
+typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
+typedef INT16_TYPE i16;            /* 2-byte signed integer */
+typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
+typedef UINT8_TYPE i8;             /* 1-byte signed integer */
+
+/*
+** Macros to determine whether the machine is big or little endian,
+** evaluated at runtime.
+*/
+#ifdef SQLITE_AMALGAMATION
+const int sqlite3one;
+#else
+extern const int sqlite3one;
+#endif
+#if defined(i386) || defined(__i386__) || defined(_M_IX86)
+# define SQLITE_BIGENDIAN    0
+# define SQLITE_LITTLEENDIAN 1
+# define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
+#else
+# define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
+# define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
+# define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
+#endif
+
+/*
+** Constants for the largest and smallest possible 64-bit signed integers.
+** These macros are designed to work correctly on both 32-bit and 64-bit
+** compilers.
+*/
+#define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
+#define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
+
+/*
+** An instance of the following structure is used to store the busy-handler
+** callback for a given sqlite handle. 
+**
+** The sqlite.busyHandler member of the sqlite struct contains the busy
+** callback for the database handle. Each pager opened via the sqlite
+** handle is passed a pointer to sqlite.busyHandler. The busy-handler
+** callback is currently invoked only from within pager.c.
+*/
+typedef struct BusyHandler BusyHandler;
+struct BusyHandler {
+  int (*xFunc)(void *,int);  /* The busy callback */
+  void *pArg;                /* First arg to busy callback */
+  int nBusy;                 /* Incremented with each busy call */
+};
+
+/*
+** Name of the master database table.  The master database table
+** is a special table that holds the names and attributes of all
+** user tables and indices.
+*/
+#define MASTER_NAME       "sqlite_master"
+#define TEMP_MASTER_NAME  "sqlite_temp_master"
+
+/*
+** The root-page of the master database table.
+*/
+#define MASTER_ROOT       1
+
+/*
+** The name of the schema table.
+*/
+#define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
+
+/*
+** A convenience macro that returns the number of elements in
+** an array.
+*/
+#define ArraySize(X)    (sizeof(X)/sizeof(X[0]))
+
+/*
+** The following value as a destructor means to use sqlite3DbFree().
+** This is an internal extension to SQLITE_STATIC and SQLITE_TRANSIENT.
+*/
+#define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3DbFree)
+
+/*
+** Forward references to structures
+*/
+typedef struct AggInfo AggInfo;
+typedef struct AuthContext AuthContext;
+typedef struct Bitvec Bitvec;
+typedef struct CollSeq CollSeq;
+typedef struct Column Column;
+typedef struct Db Db;
+typedef struct Schema Schema;
+typedef struct Expr Expr;
+typedef struct ExprList ExprList;
+typedef struct FKey FKey;
+typedef struct FuncDef FuncDef;
+typedef struct IdList IdList;
+typedef struct Index Index;
+typedef struct KeyClass KeyClass;
+typedef struct KeyInfo KeyInfo;
+typedef struct Lookaside Lookaside;
+typedef struct LookasideSlot LookasideSlot;
+typedef struct Module Module;
+typedef struct NameContext NameContext;
+typedef struct Parse Parse;
+typedef struct Select Select;
+typedef struct SrcList SrcList;
+typedef struct StrAccum StrAccum;
+typedef struct Table Table;
+typedef struct TableLock TableLock;
+typedef struct Token Token;
+typedef struct TriggerStack TriggerStack;
+typedef struct TriggerStep TriggerStep;
+typedef struct Trigger Trigger;
+typedef struct WhereInfo WhereInfo;
+typedef struct WhereLevel WhereLevel;
+
+/*
+** Defer sourcing vdbe.h and btree.h until after the "u8" and 
+** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
+** pointer types (i.e. FuncDef) defined above.
+*/
+#include "btree.h"
+#include "vdbe.h"
+#include "pager.h"
+
+#include "os.h"
+#include "mutex.h"
+
+
+/*
+** Each database file to be accessed by the system is an instance
+** of the following structure.  There are normally two of these structures
+** in the sqlite.aDb[] array.  aDb[0] is the main database file and
+** aDb[1] is the database file used to hold temporary tables.  Additional
+** databases may be attached.
+*/
+struct Db {
+  char *zName;         /* Name of this database */
+  Btree *pBt;          /* The B*Tree structure for this database file */
+  u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
+  u8 safety_level;     /* How aggressive at synching data to disk */
+  void *pAux;               /* Auxiliary data.  Usually NULL */
+  void (*xFreeAux)(void*);  /* Routine to free pAux */
+  Schema *pSchema;     /* Pointer to database schema (possibly shared) */
+};
+
+/*
+** An instance of the following structure stores a database schema.
+**
+** If there are no virtual tables configured in this schema, the
+** Schema.db variable is set to NULL. After the first virtual table
+** has been added, it is set to point to the database connection 
+** used to create the connection. Once a virtual table has been
+** added to the Schema structure and the Schema.db variable populated, 
+** only that database connection may use the Schema to prepare 
+** statements.
+*/
+struct Schema {
+  int schema_cookie;   /* Database schema version number for this file */
+  Hash tblHash;        /* All tables indexed by name */
+  Hash idxHash;        /* All (named) indices indexed by name */
+  Hash trigHash;       /* All triggers indexed by name */
+  Hash aFKey;          /* Foreign keys indexed by to-table */
+  Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
+  u8 file_format;      /* Schema format version for this file */
+  u8 enc;              /* Text encoding used by this database */
+  u16 flags;           /* Flags associated with this schema */
+  int cache_size;      /* Number of pages to use in the cache */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3 *db;         /* "Owner" connection. See comment above */
+#endif
+};
+
+/*
+** These macros can be used to test, set, or clear bits in the 
+** Db.flags field.
+*/
+#define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
+#define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
+#define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
+#define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
+
+/*
+** Allowed values for the DB.flags field.
+**
+** The DB_SchemaLoaded flag is set after the database schema has been
+** read into internal hash tables.
+**
+** DB_UnresetViews means that one or more views have column names that
+** have been filled out.  If the schema changes, these column names might
+** changes and so the view will need to be reset.
+*/
+#define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
+#define DB_UnresetViews    0x0002  /* Some views have defined column names */
+#define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
+
+/*
+** The number of different kinds of things that can be limited
+** using the sqlite3_limit() interface.
+*/
+#define SQLITE_N_LIMIT (SQLITE_LIMIT_VARIABLE_NUMBER+1)
+
+/*
+** Lookaside malloc is a set of fixed-size buffers that can be used
+** to satisify small transient memory allocation requests for objects
+** associated with a particular database connection.  The use of
+** lookaside malloc provides a significant performance enhancement
+** (approx 10%) by avoiding numerous malloc/free requests while parsing
+** SQL statements.
+**
+** The Lookaside structure holds configuration information about the
+** lookaside malloc subsystem.  Each available memory allocation in
+** the lookaside subsystem is stored on a linked list of LookasideSlot
+** objects.
+*/
+struct Lookaside {
+  u16 sz;                 /* Size of each buffer in bytes */
+  u8 bEnabled;            /* True if use lookaside.  False to ignore it */
+  u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
+  int nOut;               /* Number of buffers currently checked out */
+  int mxOut;              /* Highwater mark for nOut */
+  LookasideSlot *pFree;   /* List if available buffers */
+  void *pStart;           /* First byte of available memory space */
+  void *pEnd;             /* First byte past end of available space */
+};
+struct LookasideSlot {
+  LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
+};
+
+/*
+** Each database is an instance of the following structure.
+**
+** The sqlite.lastRowid records the last insert rowid generated by an
+** insert statement.  Inserts on views do not affect its value.  Each
+** trigger has its own context, so that lastRowid can be updated inside
+** triggers as usual.  The previous value will be restored once the trigger
+** exits.  Upon entering a before or instead of trigger, lastRowid is no
+** longer (since after version 2.8.12) reset to -1.
+**
+** The sqlite.nChange does not count changes within triggers and keeps no
+** context.  It is reset at start of sqlite3_exec.
+** The sqlite.lsChange represents the number of changes made by the last
+** insert, update, or delete statement.  It remains constant throughout the
+** length of a statement and is then updated by OP_SetCounts.  It keeps a
+** context stack just like lastRowid so that the count of changes
+** within a trigger is not seen outside the trigger.  Changes to views do not
+** affect the value of lsChange.
+** The sqlite.csChange keeps track of the number of current changes (since
+** the last statement) and is used to update sqlite_lsChange.
+**
+** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
+** store the most recent error code and, if applicable, string. The
+** internal function sqlite3Error() is used to set these variables
+** consistently.
+*/
+struct sqlite3 {
+  sqlite3_vfs *pVfs;            /* OS Interface */
+  int nDb;                      /* Number of backends currently in use */
+  Db *aDb;                      /* All backends */
+  int flags;                    /* Miscellanous flags. See below */
+  int openFlags;                /* Flags passed to sqlite3_vfs.xOpen() */
+  int errCode;                  /* Most recent error code (SQLITE_*) */
+  int errMask;                  /* & result codes with this before returning */
+  u8 autoCommit;                /* The auto-commit flag. */
+  u8 temp_store;                /* 1: file 2: memory 0: default */
+  u8 mallocFailed;              /* True if we have seen a malloc failure */
+  u8 dfltLockMode;              /* Default locking-mode for attached dbs */
+  u8 dfltJournalMode;           /* Default journal mode for attached dbs */
+  signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
+  int nextPagesize;             /* Pagesize after VACUUM if >0 */
+  int nTable;                   /* Number of tables in the database */
+  CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
+  i64 lastRowid;                /* ROWID of most recent insert (see above) */
+  i64 priorNewRowid;            /* Last randomly generated ROWID */
+  int magic;                    /* Magic number for detect library misuse */
+  int nChange;                  /* Value returned by sqlite3_changes() */
+  int nTotalChange;             /* Value returned by sqlite3_total_changes() */
+  sqlite3_mutex *mutex;         /* Connection mutex */
+  int aLimit[SQLITE_N_LIMIT];   /* Limits */
+  struct sqlite3InitInfo {      /* Information used during initialization */
+    int iDb;                    /* When back is being initialized */
+    int newTnum;                /* Rootpage of table being initialized */
+    u8 busy;                    /* TRUE if currently initializing */
+  } init;
+  int nExtension;               /* Number of loaded extensions */
+  void **aExtension;            /* Array of shared libraray handles */
+  struct Vdbe *pVdbe;           /* List of active virtual machines */
+  int activeVdbeCnt;            /* Number of vdbes currently executing */
+  void (*xTrace)(void*,const char*);        /* Trace function */
+  void *pTraceArg;                          /* Argument to the trace function */
+  void (*xProfile)(void*,const char*,u64);  /* Profiling function */
+  void *pProfileArg;                        /* Argument to profile function */
+  void *pCommitArg;                 /* Argument to xCommitCallback() */   
+  int (*xCommitCallback)(void*);    /* Invoked at every commit. */
+  void *pRollbackArg;               /* Argument to xRollbackCallback() */   
+  void (*xRollbackCallback)(void*); /* Invoked at every commit. */
+  void *pUpdateArg;
+  void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
+  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
+  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
+  void *pCollNeededArg;
+  sqlite3_value *pErr;          /* Most recent error message */
+  char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
+  char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
+  union {
+    int isInterrupted;          /* True if sqlite3_interrupt has been called */
+    double notUsed1;            /* Spacer */
+  } u1;
+  Lookaside lookaside;          /* Lookaside malloc configuration */
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
+                                /* Access authorization function */
+  void *pAuthArg;               /* 1st argument to the access auth function */
+#endif
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+  int (*xProgress)(void *);     /* The progress callback */
+  void *pProgressArg;           /* Argument to the progress callback */
+  int nProgressOps;             /* Number of opcodes for progress callback */
+#endif
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  Hash aModule;                 /* populated by sqlite3_create_module() */
+  Table *pVTab;                 /* vtab with active Connect/Create method */
+  sqlite3_vtab **aVTrans;       /* Virtual tables with open transactions */
+  int nVTrans;                  /* Allocated size of aVTrans */
+#endif
+  Hash aFunc;                   /* All functions that can be in SQL exprs */
+  Hash aCollSeq;                /* All collating sequences */
+  BusyHandler busyHandler;      /* Busy callback */
+  int busyTimeout;              /* Busy handler timeout, in msec */
+  Db aDbStatic[2];              /* Static space for the 2 default backends */
+#ifdef SQLITE_SSE
+  sqlite3_stmt *pFetch;         /* Used by SSE to fetch stored statements */
+#endif
+};
+
+/*
+** A macro to discover the encoding of a database.
+*/
+#define ENC(db) ((db)->aDb[0].pSchema->enc)
+
+/*
+** Possible values for the sqlite.flags and or Db.flags fields.
+**
+** On sqlite.flags, the SQLITE_InTrans value means that we have
+** executed a BEGIN.  On Db.flags, SQLITE_InTrans means a statement
+** transaction is active on that particular database file.
+*/
+#define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
+#define SQLITE_InTrans        0x00000008  /* True if in a transaction */
+#define SQLITE_InternChanges  0x00000010  /* Uncommitted Hash table changes */
+#define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
+#define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
+#define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
+                                          /*   DELETE, or UPDATE and return */
+                                          /*   the count using a callback. */
+#define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
+                                          /*   result set is empty */
+#define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
+#define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
+#define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
+#define SQLITE_NoReadlock     0x00001000  /* Readlocks are omitted when 
+                                          ** accessing read-only databases */
+#define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
+#define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */
+#define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
+#define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
+#define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */
+
+#define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
+#define SQLITE_SharedCache    0x00080000  /* Cache sharing is enabled */
+#define SQLITE_Vtab           0x00100000  /* There exists a virtual table */
+
+/*
+** Possible values for the sqlite.magic field.
+** The numbers are obtained at random and have no special meaning, other
+** than being distinct from one another.
+*/
+#define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
+#define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
+#define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
+#define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
+#define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
+
+/*
+** Each SQL function is defined by an instance of the following
+** structure.  A pointer to this structure is stored in the sqlite.aFunc
+** hash table.  When multiple functions have the same name, the hash table
+** points to a linked list of these structures.
+*/
+struct FuncDef {
+  i16 nArg;            /* Number of arguments.  -1 means unlimited */
+  u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
+  u8 needCollSeq;      /* True if sqlite3GetFuncCollSeq() might be called */
+  u8 flags;            /* Some combination of SQLITE_FUNC_* */
+  void *pUserData;     /* User data parameter */
+  FuncDef *pNext;      /* Next function with same name */
+  void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
+  void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
+  void (*xFinalize)(sqlite3_context*);                /* Aggregate finializer */
+  char zName[1];       /* SQL name of the function.  MUST BE LAST */
+};
+
+/*
+** Each SQLite module (virtual table definition) is defined by an
+** instance of the following structure, stored in the sqlite3.aModule
+** hash table.
+*/
+struct Module {
+  const sqlite3_module *pModule;       /* Callback pointers */
+  const char *zName;                   /* Name passed to create_module() */
+  void *pAux;                          /* pAux passed to create_module() */
+  void (*xDestroy)(void *);            /* Module destructor function */
+};
+
+/*
+** Possible values for FuncDef.flags
+*/
+#define SQLITE_FUNC_LIKE   0x01  /* Candidate for the LIKE optimization */
+#define SQLITE_FUNC_CASE   0x02  /* Case-sensitive LIKE-type function */
+#define SQLITE_FUNC_EPHEM  0x04  /* Ephermeral.  Delete with VDBE */
+
+/*
+** information about each column of an SQL table is held in an instance
+** of this structure.
+*/
+struct Column {
+  char *zName;     /* Name of this column */
+  Expr *pDflt;     /* Default value of this column */
+  char *zType;     /* Data type for this column */
+  char *zColl;     /* Collating sequence.  If NULL, use the default */
+  u8 notNull;      /* True if there is a NOT NULL constraint */
+  u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
+  char affinity;   /* One of the SQLITE_AFF_... values */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  u8 isHidden;     /* True if this column is 'hidden' */
+#endif
+};
+
+/*
+** A "Collating Sequence" is defined by an instance of the following
+** structure. Conceptually, a collating sequence consists of a name and
+** a comparison routine that defines the order of that sequence.
+**
+** There may two seperate implementations of the collation function, one
+** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
+** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
+** native byte order. When a collation sequence is invoked, SQLite selects
+** the version that will require the least expensive encoding
+** translations, if any.
+**
+** The CollSeq.pUser member variable is an extra parameter that passed in
+** as the first argument to the UTF-8 comparison function, xCmp.
+** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
+** xCmp16.
+**
+** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
+** collating sequence is undefined.  Indices built on an undefined
+** collating sequence may not be read or written.
+*/
+struct CollSeq {
+  char *zName;          /* Name of the collating sequence, UTF-8 encoded */
+  u8 enc;               /* Text encoding handled by xCmp() */
+  u8 type;              /* One of the SQLITE_COLL_... values below */
+  void *pUser;          /* First argument to xCmp() */
+  int (*xCmp)(void*,int, const void*, int, const void*);
+  void (*xDel)(void*);  /* Destructor for pUser */
+};
+
+/*
+** Allowed values of CollSeq flags:
+*/
+#define SQLITE_COLL_BINARY  1  /* The default memcmp() collating sequence */
+#define SQLITE_COLL_NOCASE  2  /* The built-in NOCASE collating sequence */
+#define SQLITE_COLL_REVERSE 3  /* The built-in REVERSE collating sequence */
+#define SQLITE_COLL_USER    0  /* Any other user-defined collating sequence */
+
+/*
+** A sort order can be either ASC or DESC.
+*/
+#define SQLITE_SO_ASC       0  /* Sort in ascending order */
+#define SQLITE_SO_DESC      1  /* Sort in ascending order */
+
+/*
+** Column affinity types.
+**
+** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
+** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
+** the speed a little by number the values consecutively.  
+**
+** But rather than start with 0 or 1, we begin with 'a'.  That way,
+** when multiple affinity types are concatenated into a string and
+** used as the P4 operand, they will be more readable.
+**
+** Note also that the numeric types are grouped together so that testing
+** for a numeric type is a single comparison.
+*/
+#define SQLITE_AFF_TEXT     'a'
+#define SQLITE_AFF_NONE     'b'
+#define SQLITE_AFF_NUMERIC  'c'
+#define SQLITE_AFF_INTEGER  'd'
+#define SQLITE_AFF_REAL     'e'
+
+#define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
+
+/*
+** The SQLITE_AFF_MASK values masks off the significant bits of an
+** affinity value. 
+*/
+#define SQLITE_AFF_MASK     0x67
+
+/*
+** Additional bit values that can be ORed with an affinity without
+** changing the affinity.
+*/
+#define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
+#define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
+
+/*
+** Each SQL table is represented in memory by an instance of the
+** following structure.
+**
+** Table.zName is the name of the table.  The case of the original
+** CREATE TABLE statement is stored, but case is not significant for
+** comparisons.
+**
+** Table.nCol is the number of columns in this table.  Table.aCol is a
+** pointer to an array of Column structures, one for each column.
+**
+** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
+** the column that is that key.   Otherwise Table.iPKey is negative.  Note
+** that the datatype of the PRIMARY KEY must be INTEGER for this field to
+** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
+** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
+** is generated for each row of the table.  Table.hasPrimKey is true if
+** the table has any PRIMARY KEY, INTEGER or otherwise.
+**
+** Table.tnum is the page number for the root BTree page of the table in the
+** database file.  If Table.iDb is the index of the database table backend
+** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
+** holds temporary tables and indices.  If Table.isEphem
+** is true, then the table is stored in a file that is automatically deleted
+** when the VDBE cursor to the table is closed.  In this case Table.tnum 
+** refers VDBE cursor number that holds the table open, not to the root
+** page number.  Transient tables are used to hold the results of a
+** sub-query that appears instead of a real table name in the FROM clause 
+** of a SELECT statement.
+*/
+struct Table {
+  sqlite3 *db;     /* Associated database connection.  Might be NULL. */
+  char *zName;     /* Name of the table */
+  int nCol;        /* Number of columns in this table */
+  Column *aCol;    /* Information about each column */
+  int iPKey;       /* If not less then 0, use aCol[iPKey] as the primary key */
+  Index *pIndex;   /* List of SQL indexes on this table. */
+  int tnum;        /* Root BTree node for this table (see note above) */
+  Select *pSelect; /* NULL for tables.  Points to definition if a view. */
+  int nRef;          /* Number of pointers to this Table */
+  Trigger *pTrigger; /* List of SQL triggers on this table */
+  FKey *pFKey;       /* Linked list of all foreign keys in this table */
+  char *zColAff;     /* String defining the affinity of each column */
+#ifndef SQLITE_OMIT_CHECK
+  Expr *pCheck;      /* The AND of all CHECK constraints */
+#endif
+#ifndef SQLITE_OMIT_ALTERTABLE
+  int addColOffset;  /* Offset in CREATE TABLE statement to add a new column */
+#endif
+  u8 readOnly;     /* True if this table should not be written by the user */
+  u8 isEphem;      /* True if created using OP_OpenEphermeral */
+  u8 hasPrimKey;   /* True if there exists a primary key */
+  u8 keyConf;      /* What to do in case of uniqueness conflict on iPKey */
+  u8 autoInc;      /* True if the integer primary key is autoincrement */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  u8 isVirtual;             /* True if this is a virtual table */
+  u8 isCommit;              /* True once the CREATE TABLE has been committed */
+  Module *pMod;             /* Pointer to the implementation of the module */
+  sqlite3_vtab *pVtab;      /* Pointer to the module instance */
+  int nModuleArg;           /* Number of arguments to the module */
+  char **azModuleArg;       /* Text of all module args. [0] is module name */
+#endif
+  Schema *pSchema;          /* Schema that contains this table */
+};
+
+/*
+** Test to see whether or not a table is a virtual table.  This is
+** done as a macro so that it will be optimized out when virtual
+** table support is omitted from the build.
+*/
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+#  define IsVirtual(X)      ((X)->isVirtual)
+#  define IsHiddenColumn(X) ((X)->isHidden)
+#else
+#  define IsVirtual(X)      0
+#  define IsHiddenColumn(X) 0
+#endif
+
+/*
+** Each foreign key constraint is an instance of the following structure.
+**
+** A foreign key is associated with two tables.  The "from" table is
+** the table that contains the REFERENCES clause that creates the foreign
+** key.  The "to" table is the table that is named in the REFERENCES clause.
+** Consider this example:
+**
+**     CREATE TABLE ex1(
+**       a INTEGER PRIMARY KEY,
+**       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
+**     );
+**
+** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
+**
+** Each REFERENCES clause generates an instance of the following structure
+** which is attached to the from-table.  The to-table need not exist when
+** the from-table is created.  The existance of the to-table is not checked
+** until an attempt is made to insert data into the from-table.
+**
+** The sqlite.aFKey hash table stores pointers to this structure
+** given the name of a to-table.  For each to-table, all foreign keys
+** associated with that table are on a linked list using the FKey.pNextTo
+** field.
+*/
+struct FKey {
+  Table *pFrom;     /* The table that constains the REFERENCES clause */
+  FKey *pNextFrom;  /* Next foreign key in pFrom */
+  char *zTo;        /* Name of table that the key points to */
+  FKey *pNextTo;    /* Next foreign key that points to zTo */
+  int nCol;         /* Number of columns in this key */
+  struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
+    int iFrom;         /* Index of column in pFrom */
+    char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
+  } *aCol;          /* One entry for each of nCol column s */
+  u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
+  u8 updateConf;    /* How to resolve conflicts that occur on UPDATE */
+  u8 deleteConf;    /* How to resolve conflicts that occur on DELETE */
+  u8 insertConf;    /* How to resolve conflicts that occur on INSERT */
+};
+
+/*
+** SQLite supports many different ways to resolve a constraint
+** error.  ROLLBACK processing means that a constraint violation
+** causes the operation in process to fail and for the current transaction
+** to be rolled back.  ABORT processing means the operation in process
+** fails and any prior changes from that one operation are backed out,
+** but the transaction is not rolled back.  FAIL processing means that
+** the operation in progress stops and returns an error code.  But prior
+** changes due to the same operation are not backed out and no rollback
+** occurs.  IGNORE means that the particular row that caused the constraint
+** error is not inserted or updated.  Processing continues and no error
+** is returned.  REPLACE means that preexisting database rows that caused
+** a UNIQUE constraint violation are removed so that the new insert or
+** update can proceed.  Processing continues and no error is reported.
+**
+** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
+** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
+** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
+** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
+** referenced table row is propagated into the row that holds the
+** foreign key.
+** 
+** The following symbolic values are used to record which type
+** of action to take.
+*/
+#define OE_None     0   /* There is no constraint to check */
+#define OE_Rollback 1   /* Fail the operation and rollback the transaction */
+#define OE_Abort    2   /* Back out changes but do no rollback transaction */
+#define OE_Fail     3   /* Stop the operation but leave all prior changes */
+#define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
+#define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
+
+#define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
+#define OE_SetNull  7   /* Set the foreign key value to NULL */
+#define OE_SetDflt  8   /* Set the foreign key value to its default */
+#define OE_Cascade  9   /* Cascade the changes */
+
+#define OE_Default  99  /* Do whatever the default action is */
+
+
+/*
+** An instance of the following structure is passed as the first
+** argument to sqlite3VdbeKeyCompare and is used to control the 
+** comparison of the two index keys.
+**
+** If the KeyInfo.incrKey value is true and the comparison would
+** otherwise be equal, then return a result as if the second key
+** were larger.
+*/
+struct KeyInfo {
+  sqlite3 *db;        /* The database connection */
+  u8 enc;             /* Text encoding - one of the TEXT_Utf* values */
+  u8 incrKey;         /* Increase 2nd key by epsilon before comparison */
+  u8 prefixIsEqual;   /* Treat a prefix as equal */
+  int nField;         /* Number of entries in aColl[] */
+  u8 *aSortOrder;     /* If defined an aSortOrder[i] is true, sort DESC */
+  CollSeq *aColl[1];  /* Collating sequence for each term of the key */
+};
+
+/*
+** Each SQL index is represented in memory by an
+** instance of the following structure.
+**
+** The columns of the table that are to be indexed are described
+** by the aiColumn[] field of this structure.  For example, suppose
+** we have the following table and index:
+**
+**     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
+**     CREATE INDEX Ex2 ON Ex1(c3,c1);
+**
+** In the Table structure describing Ex1, nCol==3 because there are
+** three columns in the table.  In the Index structure describing
+** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
+** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the 
+** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
+** The second column to be indexed (c1) has an index of 0 in
+** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
+**
+** The Index.onError field determines whether or not the indexed columns
+** must be unique and what to do if they are not.  When Index.onError=OE_None,
+** it means this is not a unique index.  Otherwise it is a unique index
+** and the value of Index.onError indicate the which conflict resolution 
+** algorithm to employ whenever an attempt is made to insert a non-unique
+** element.
+*/
+struct Index {
+  char *zName;     /* Name of this index */
+  int nColumn;     /* Number of columns in the table used by this index */
+  int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
+  unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
+  Table *pTable;   /* The SQL table being indexed */
+  int tnum;        /* Page containing root of this index in database file */
+  u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
+  u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
+  char *zColAff;   /* String defining the affinity of each column */
+  Index *pNext;    /* The next index associated with the same table */
+  Schema *pSchema; /* Schema containing this index */
+  u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
+  char **azColl;   /* Array of collation sequence names for index */
+};
+
+/*
+** Each token coming out of the lexer is an instance of
+** this structure.  Tokens are also used as part of an expression.
+**
+** Note if Token.z==0 then Token.dyn and Token.n are undefined and
+** may contain random values.  Do not make any assuptions about Token.dyn
+** and Token.n when Token.z==0.
+*/
+struct Token {
+  const unsigned char *z; /* Text of the token.  Not NULL-terminated! */
+  unsigned dyn  : 1;      /* True for malloced memory, false for static */
+  unsigned n    : 31;     /* Number of characters in this token */
+};
+
+/*
+** An instance of this structure contains information needed to generate
+** code for a SELECT that contains aggregate functions.
+**
+** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
+** pointer to this structure.  The Expr.iColumn field is the index in
+** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
+** code for that node.
+**
+** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
+** original Select structure that describes the SELECT statement.  These
+** fields do not need to be freed when deallocating the AggInfo structure.
+*/
+struct AggInfo {
+  u8 directMode;          /* Direct rendering mode means take data directly
+                          ** from source tables rather than from accumulators */
+  u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
+                          ** than the source table */
+  int sortingIdx;         /* Cursor number of the sorting index */
+  ExprList *pGroupBy;     /* The group by clause */
+  int nSortingColumn;     /* Number of columns in the sorting index */
+  struct AggInfo_col {    /* For each column used in source tables */
+    Table *pTab;             /* Source table */
+    int iTable;              /* Cursor number of the source table */
+    int iColumn;             /* Column number within the source table */
+    int iSorterColumn;       /* Column number in the sorting index */
+    int iMem;                /* Memory location that acts as accumulator */
+    Expr *pExpr;             /* The original expression */
+  } *aCol;
+  int nColumn;            /* Number of used entries in aCol[] */
+  int nColumnAlloc;       /* Number of slots allocated for aCol[] */
+  int nAccumulator;       /* Number of columns that show through to the output.
+                          ** Additional columns are used only as parameters to
+                          ** aggregate functions */
+  struct AggInfo_func {   /* For each aggregate function */
+    Expr *pExpr;             /* Expression encoding the function */
+    FuncDef *pFunc;          /* The aggregate function implementation */
+    int iMem;                /* Memory location that acts as accumulator */
+    int iDistinct;           /* Ephermeral table used to enforce DISTINCT */
+  } *aFunc;
+  int nFunc;              /* Number of entries in aFunc[] */
+  int nFuncAlloc;         /* Number of slots allocated for aFunc[] */
+};
+
+/*
+** Each node of an expression in the parse tree is an instance
+** of this structure.
+**
+** Expr.op is the opcode.  The integer parser token codes are reused
+** as opcodes here.  For example, the parser defines TK_GE to be an integer
+** code representing the ">=" operator.  This same integer code is reused
+** to represent the greater-than-or-equal-to operator in the expression
+** tree.
+**
+** Expr.pRight and Expr.pLeft are subexpressions.  Expr.pList is a list
+** of argument if the expression is a function.
+**
+** Expr.token is the operator token for this node.  For some expressions
+** that have subexpressions, Expr.token can be the complete text that gave
+** rise to the Expr.  In the latter case, the token is marked as being
+** a compound token.
+**
+** An expression of the form ID or ID.ID refers to a column in a table.
+** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
+** the integer cursor number of a VDBE cursor pointing to that table and
+** Expr.iColumn is the column number for the specific column.  If the
+** expression is used as a result in an aggregate SELECT, then the
+** value is also stored in the Expr.iAgg column in the aggregate so that
+** it can be accessed after all aggregates are computed.
+**
+** If the expression is a function, the Expr.iTable is an integer code
+** representing which function.  If the expression is an unbound variable
+** marker (a question mark character '?' in the original SQL) then the
+** Expr.iTable holds the index number for that variable.
+**
+** If the expression is a subquery then Expr.iColumn holds an integer
+** register number containing the result of the subquery.  If the
+** subquery gives a constant result, then iTable is -1.  If the subquery
+** gives a different answer at different times during statement processing
+** then iTable is the address of a subroutine that computes the subquery.
+**
+** The Expr.pSelect field points to a SELECT statement.  The SELECT might
+** be the right operand of an IN operator.  Or, if a scalar SELECT appears
+** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
+** operand.
+**
+** If the Expr is of type OP_Column, and the table it is selecting from
+** is a disk table or the "old.*" pseudo-table, then pTab points to the
+** corresponding table definition.
+*/
+struct Expr {
+  u8 op;                 /* Operation performed by this node */
+  char affinity;         /* The affinity of the column or 0 if not a column */
+  u16 flags;             /* Various flags.  See below */
+  CollSeq *pColl;        /* The collation type of the column or 0 */
+  Expr *pLeft, *pRight;  /* Left and right subnodes */
+  ExprList *pList;       /* A list of expressions used as function arguments
+                         ** or in "<expr> IN (<expr-list)" */
+  Token token;           /* An operand token */
+  Token span;            /* Complete text of the expression */
+  int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the
+                         ** iColumn-th field of the iTable-th table. */
+  AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
+  int iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
+  int iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
+  Select *pSelect;       /* When the expression is a sub-select.  Also the
+                         ** right side of "<expr> IN (<select>)" */
+  Table *pTab;           /* Table for OP_Column expressions. */
+#if SQLITE_MAX_EXPR_DEPTH>0
+  int nHeight;           /* Height of the tree headed by this node */
+#endif
+};
+
+/*
+** The following are the meanings of bits in the Expr.flags field.
+*/
+#define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
+#define EP_Agg        0x0002  /* Contains one or more aggregate functions */
+#define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
+#define EP_Error      0x0008  /* Expression contains one or more errors */
+#define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
+#define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
+#define EP_Dequoted   0x0040  /* True if the string has been dequoted */
+#define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
+#define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
+#define EP_AnyAff     0x0200  /* Can take a cached column of any affinity */
+#define EP_FixedDest  0x0400  /* Result needed in a specific register */
+#define EP_IntValue   0x0800  /* Integer value contained in iTable */
+/*
+** These macros can be used to test, set, or clear bits in the 
+** Expr.flags field.
+*/
+#define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
+#define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
+#define ExprSetProperty(E,P)     (E)->flags|=(P)
+#define ExprClearProperty(E,P)   (E)->flags&=~(P)
+
+/*
+** A list of expressions.  Each expression may optionally have a
+** name.  An expr/name combination can be used in several ways, such
+** as the list of "expr AS ID" fields following a "SELECT" or in the
+** list of "ID = expr" items in an UPDATE.  A list of expressions can
+** also be used as the argument to a function, in which case the a.zName
+** field is not used.
+*/
+struct ExprList {
+  int nExpr;             /* Number of expressions on the list */
+  int nAlloc;            /* Number of entries allocated below */
+  int iECursor;          /* VDBE Cursor associated with this ExprList */
+  struct ExprList_item {
+    Expr *pExpr;           /* The list of expressions */
+    char *zName;           /* Token associated with this expression */
+    u8 sortOrder;          /* 1 for DESC or 0 for ASC */
+    u8 isAgg;              /* True if this is an aggregate like count(*) */
+    u8 done;               /* A flag to indicate when processing is finished */
+  } *a;                  /* One entry for each expression */
+};
+
+/*
+** An instance of this structure can hold a simple list of identifiers,
+** such as the list "a,b,c" in the following statements:
+**
+**      INSERT INTO t(a,b,c) VALUES ...;
+**      CREATE INDEX idx ON t(a,b,c);
+**      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
+**
+** The IdList.a.idx field is used when the IdList represents the list of
+** column names after a table name in an INSERT statement.  In the statement
+**
+**     INSERT INTO t(a,b,c) ...
+**
+** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
+*/
+struct IdList {
+  struct IdList_item {
+    char *zName;      /* Name of the identifier */
+    int idx;          /* Index in some Table.aCol[] of a column named zName */
+  } *a;
+  int nId;         /* Number of identifiers on the list */
+  int nAlloc;      /* Number of entries allocated for a[] below */
+};
+
+/*
+** The bitmask datatype defined below is used for various optimizations.
+**
+** Changing this from a 64-bit to a 32-bit type limits the number of
+** tables in a join to 32 instead of 64.  But it also reduces the size
+** of the library by 738 bytes on ix86.
+*/
+typedef u64 Bitmask;
+
+/*
+** The following structure describes the FROM clause of a SELECT statement.
+** Each table or subquery in the FROM clause is a separate element of
+** the SrcList.a[] array.
+**
+** With the addition of multiple database support, the following structure
+** can also be used to describe a particular table such as the table that
+** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
+** such a table must be a simple name: ID.  But in SQLite, the table can
+** now be identified by a database name, a dot, then the table name: ID.ID.
+**
+** The jointype starts out showing the join type between the current table
+** and the next table on the list.  The parser builds the list this way.
+** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
+** jointype expresses the join between the table and the previous table.
+*/
+struct SrcList {
+  i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
+  i16 nAlloc;      /* Number of entries allocated in a[] below */
+  struct SrcList_item {
+    char *zDatabase;  /* Name of database holding this table */
+    char *zName;      /* Name of the table */
+    char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
+    Table *pTab;      /* An SQL table corresponding to zName */
+    Select *pSelect;  /* A SELECT statement used in place of a table name */
+    u8 isPopulated;   /* Temporary table associated with SELECT is populated */
+    u8 jointype;      /* Type of join between this able and the previous */
+    int iCursor;      /* The VDBE cursor number used to access this table */
+    Expr *pOn;        /* The ON clause of a join */
+    IdList *pUsing;   /* The USING clause of a join */
+    Bitmask colUsed;  /* Bit N (1<<N) set if column N or pTab is used */
+  } a[1];             /* One entry for each identifier on the list */
+};
+
+/*
+** Permitted values of the SrcList.a.jointype field
+*/
+#define JT_INNER     0x0001    /* Any kind of inner or cross join */
+#define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
+#define JT_NATURAL   0x0004    /* True for a "natural" join */
+#define JT_LEFT      0x0008    /* Left outer join */
+#define JT_RIGHT     0x0010    /* Right outer join */
+#define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
+#define JT_ERROR     0x0040    /* unknown or unsupported join type */
+
+/*
+** For each nested loop in a WHERE clause implementation, the WhereInfo
+** structure contains a single instance of this structure.  This structure
+** is intended to be private the the where.c module and should not be
+** access or modified by other modules.
+**
+** The pIdxInfo and pBestIdx fields are used to help pick the best
+** index on a virtual table.  The pIdxInfo pointer contains indexing
+** information for the i-th table in the FROM clause before reordering.
+** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
+** The pBestIdx pointer is a copy of pIdxInfo for the i-th table after
+** FROM clause ordering.  This is a little confusing so I will repeat
+** it in different words.  WhereInfo.a[i].pIdxInfo is index information 
+** for WhereInfo.pTabList.a[i].  WhereInfo.a[i].pBestInfo is the
+** index information for the i-th loop of the join.  pBestInfo is always
+** either NULL or a copy of some pIdxInfo.  So for cleanup it is 
+** sufficient to free all of the pIdxInfo pointers.
+** 
+*/
+struct WhereLevel {
+  int iFrom;            /* Which entry in the FROM clause */
+  int flags;            /* Flags associated with this level */
+  int iMem;             /* First memory cell used by this level */
+  int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
+  Index *pIdx;          /* Index used.  NULL if no index */
+  int iTabCur;          /* The VDBE cursor used to access the table */
+  int iIdxCur;          /* The VDBE cursor used to acesss pIdx */
+  int brk;              /* Jump here to break out of the loop */
+  int nxt;              /* Jump here to start the next IN combination */
+  int cont;             /* Jump here to continue with the next loop cycle */
+  int top;              /* First instruction of interior of the loop */
+  int op, p1, p2;       /* Opcode used to terminate the loop */
+  int nEq;              /* Number of == or IN constraints on this loop */
+  int nIn;              /* Number of IN operators constraining this loop */
+  struct InLoop {
+    int iCur;              /* The VDBE cursor used by this IN operator */
+    int topAddr;           /* Top of the IN loop */
+  } *aInLoop;           /* Information about each nested IN operator */
+  sqlite3_index_info *pBestIdx;  /* Index information for this level */
+
+  /* The following field is really not part of the current level.  But
+  ** we need a place to cache index information for each table in the
+  ** FROM clause and the WhereLevel structure is a convenient place.
+  */
+  sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
+};
+
+/*
+** Flags appropriate for the wflags parameter of sqlite3WhereBegin().
+*/
+#define WHERE_ORDERBY_NORMAL     0   /* No-op */
+#define WHERE_ORDERBY_MIN        1   /* ORDER BY processing for min() func */
+#define WHERE_ORDERBY_MAX        2   /* ORDER BY processing for max() func */
+#define WHERE_ONEPASS_DESIRED    4   /* Want to do one-pass UPDATE/DELETE */
+
+/*
+** The WHERE clause processing routine has two halves.  The
+** first part does the start of the WHERE loop and the second
+** half does the tail of the WHERE loop.  An instance of
+** this structure is returned by the first half and passed
+** into the second half to give some continuity.
+*/
+struct WhereInfo {
+  Parse *pParse;       /* Parsing and code generating context */
+  u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
+  SrcList *pTabList;   /* List of tables in the join */
+  int iTop;            /* The very beginning of the WHERE loop */
+  int iContinue;       /* Jump here to continue with next record */
+  int iBreak;          /* Jump here to break out of the loop */
+  int nLevel;          /* Number of nested loop */
+  sqlite3_index_info **apInfo;  /* Array of pointers to index info structures */
+  WhereLevel a[1];     /* Information about each nest loop in the WHERE */
+};
+
+/*
+** A NameContext defines a context in which to resolve table and column
+** names.  The context consists of a list of tables (the pSrcList) field and
+** a list of named expression (pEList).  The named expression list may
+** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
+** to the table being operated on by INSERT, UPDATE, or DELETE.  The
+** pEList corresponds to the result set of a SELECT and is NULL for
+** other statements.
+**
+** NameContexts can be nested.  When resolving names, the inner-most 
+** context is searched first.  If no match is found, the next outer
+** context is checked.  If there is still no match, the next context
+** is checked.  This process continues until either a match is found
+** or all contexts are check.  When a match is found, the nRef member of
+** the context containing the match is incremented. 
+**
+** Each subquery gets a new NameContext.  The pNext field points to the
+** NameContext in the parent query.  Thus the process of scanning the
+** NameContext list corresponds to searching through successively outer
+** subqueries looking for a match.
+*/
+struct NameContext {
+  Parse *pParse;       /* The parser */
+  SrcList *pSrcList;   /* One or more tables used to resolve names */
+  ExprList *pEList;    /* Optional list of named expressions */
+  int nRef;            /* Number of names resolved by this context */
+  int nErr;            /* Number of errors encountered while resolving names */
+  u8 allowAgg;         /* Aggregate functions allowed here */
+  u8 hasAgg;           /* True if aggregates are seen */
+  u8 isCheck;          /* True if resolving names in a CHECK constraint */
+  int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
+  AggInfo *pAggInfo;   /* Information about aggregates at this level */
+  NameContext *pNext;  /* Next outer name context.  NULL for outermost */
+};
+
+/*
+** An instance of the following structure contains all information
+** needed to generate code for a single SELECT statement.
+**
+** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
+** If there is a LIMIT clause, the parser sets nLimit to the value of the
+** limit and nOffset to the value of the offset (or 0 if there is not
+** offset).  But later on, nLimit and nOffset become the memory locations
+** in the VDBE that record the limit and offset counters.
+**
+** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
+** These addresses must be stored so that we can go back and fill in
+** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
+** the number of columns in P2 can be computed at the same time
+** as the OP_OpenEphm instruction is coded because not
+** enough information about the compound query is known at that point.
+** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
+** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
+** sequences for the ORDER BY clause.
+*/
+struct Select {
+  ExprList *pEList;      /* The fields of the result */
+  u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
+  u8 isDistinct;         /* True if the DISTINCT keyword is present */
+  u8 isResolved;         /* True once sqlite3SelectResolve() has run. */
+  u8 isAgg;              /* True if this is an aggregate query */
+  u8 usesEphm;           /* True if uses an OpenEphemeral opcode */
+  u8 disallowOrderBy;    /* Do not allow an ORDER BY to be attached if TRUE */
+  char affinity;         /* MakeRecord with this affinity for SRT_Set */
+  SrcList *pSrc;         /* The FROM clause */
+  Expr *pWhere;          /* The WHERE clause */
+  ExprList *pGroupBy;    /* The GROUP BY clause */
+  Expr *pHaving;         /* The HAVING clause */
+  ExprList *pOrderBy;    /* The ORDER BY clause */
+  Select *pPrior;        /* Prior select in a compound select statement */
+  Select *pNext;         /* Next select to the left in a compound */
+  Select *pRightmost;    /* Right-most select in a compound select statement */
+  Expr *pLimit;          /* LIMIT expression. NULL means not used. */
+  Expr *pOffset;         /* OFFSET expression. NULL means not used. */
+  int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
+  int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
+};
+
+/*
+** The results of a select can be distributed in several ways.
+*/
+#define SRT_Union        1  /* Store result as keys in an index */
+#define SRT_Except       2  /* Remove result from a UNION index */
+#define SRT_Exists       3  /* Store 1 if the result is not empty */
+#define SRT_Discard      4  /* Do not save the results anywhere */
+
+/* The ORDER BY clause is ignored for all of the above */
+#define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
+
+#define SRT_Callback     5  /* Invoke a callback with each row of result */
+#define SRT_Mem          6  /* Store result in a memory cell */
+#define SRT_Set          7  /* Store results as keys in an index */
+#define SRT_Table        8  /* Store result as data with an automatic rowid */
+#define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
+#define SRT_Coroutine   10  /* Generate a single row of result */
+
+/*
+** A structure used to customize the behaviour of sqlite3Select(). See
+** comments above sqlite3Select() for details.
+*/
+typedef struct SelectDest SelectDest;
+struct SelectDest {
+  u8 eDest;         /* How to dispose of the results */
+  u8 affinity;      /* Affinity used when eDest==SRT_Set */
+  int iParm;        /* A parameter used by the eDest disposal method */
+  int iMem;         /* Base register where results are written */
+  int nMem;         /* Number of registers allocated */
+};
+
+/*
+** An SQL parser context.  A copy of this structure is passed through
+** the parser and down into all the parser action routine in order to
+** carry around information that is global to the entire parse.
+**
+** The structure is divided into two parts.  When the parser and code
+** generate call themselves recursively, the first part of the structure
+** is constant but the second part is reset at the beginning and end of
+** each recursion.
+**
+** The nTableLock and aTableLock variables are only used if the shared-cache 
+** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
+** used to store the set of table-locks required by the statement being
+** compiled. Function sqlite3TableLock() is used to add entries to the
+** list.
+*/
+struct Parse {
+  sqlite3 *db;         /* The main database structure */
+  int rc;              /* Return code from execution */
+  char *zErrMsg;       /* An error message */
+  Vdbe *pVdbe;         /* An engine for executing database bytecode */
+  u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
+  u8 nameClash;        /* A permanent table name clashes with temp table name */
+  u8 checkSchema;      /* Causes schema cookie check after an error */
+  u8 nested;           /* Number of nested calls to the parser/code generator */
+  u8 parseError;       /* True after a parsing error.  Ticket #1794 */
+  u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
+  u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
+  int aTempReg[8];     /* Holding area for temporary registers */
+  int nRangeReg;       /* Size of the temporary register block */
+  int iRangeReg;       /* First register in temporary register block */
+  int nErr;            /* Number of errors seen */
+  int nTab;            /* Number of previously allocated VDBE cursors */
+  int nMem;            /* Number of memory cells used so far */
+  int nSet;            /* Number of sets used so far */
+  int ckBase;          /* Base register of data during check constraints */
+  int disableColCache; /* True to disable adding to column cache */
+  int nColCache;       /* Number of entries in the column cache */
+  int iColCache;       /* Next entry of the cache to replace */
+  struct yColCache {
+    int iTable;           /* Table cursor number */
+    int iColumn;          /* Table column number */
+    char affChange;       /* True if this register has had an affinity change */
+    int iReg;             /* Register holding value of this column */
+  } aColCache[10];     /* One for each valid column cache entry */
+  u32 writeMask;       /* Start a write transaction on these databases */
+  u32 cookieMask;      /* Bitmask of schema verified databases */
+  int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
+  int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  int nTableLock;        /* Number of locks in aTableLock */
+  TableLock *aTableLock; /* Required table locks for shared-cache mode */
+#endif
+  int regRowid;        /* Register holding rowid of CREATE TABLE entry */
+  int regRoot;         /* Register holding root page number for new objects */
+
+  /* Above is constant between recursions.  Below is reset before and after
+  ** each recursion */
+
+  int nVar;            /* Number of '?' variables seen in the SQL so far */
+  int nVarExpr;        /* Number of used slots in apVarExpr[] */
+  int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */
+  Expr **apVarExpr;    /* Pointers to :aaa and $aaaa wildcard expressions */
+  u8 explain;          /* True if the EXPLAIN flag is found on the query */
+  Token sErrToken;     /* The token at which the error occurred */
+  Token sNameToken;    /* Token with unqualified schema object name */
+  Token sLastToken;    /* The last token parsed */
+  const char *zSql;    /* All SQL text */
+  const char *zTail;   /* All SQL text past the last semicolon parsed */
+  Table *pNewTable;    /* A table being constructed by CREATE TABLE */
+  Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
+  TriggerStack *trigStack;  /* Trigger actions being coded */
+  const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  Token sArg;                /* Complete text of a module argument */
+  u8 declareVtab;            /* True if inside sqlite3_declare_vtab() */
+  int nVtabLock;             /* Number of virtual tables to lock */
+  Table **apVtabLock;        /* Pointer to virtual tables needing locking */
+#endif
+  int nHeight;            /* Expression tree height of current sub-select */
+};
+
+#ifdef SQLITE_OMIT_VIRTUALTABLE
+  #define IN_DECLARE_VTAB 0
+#else
+  #define IN_DECLARE_VTAB (pParse->declareVtab)
+#endif
+
+/*
+** An instance of the following structure can be declared on a stack and used
+** to save the Parse.zAuthContext value so that it can be restored later.
+*/
+struct AuthContext {
+  const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
+  Parse *pParse;              /* The Parse structure */
+};
+
+/*
+** Bitfield flags for P2 value in OP_Insert and OP_Delete
+*/
+#define OPFLAG_NCHANGE   1    /* Set to update db->nChange */
+#define OPFLAG_LASTROWID 2    /* Set to update db->lastRowid */
+#define OPFLAG_ISUPDATE  4    /* This OP_Insert is an sql UPDATE */
+#define OPFLAG_APPEND    8    /* This is likely to be an append */
+
+/*
+ * Each trigger present in the database schema is stored as an instance of
+ * struct Trigger. 
+ *
+ * Pointers to instances of struct Trigger are stored in two ways.
+ * 1. In the "trigHash" hash table (part of the sqlite3* that represents the 
+ *    database). This allows Trigger structures to be retrieved by name.
+ * 2. All triggers associated with a single table form a linked list, using the
+ *    pNext member of struct Trigger. A pointer to the first element of the
+ *    linked list is stored as the "pTrigger" member of the associated
+ *    struct Table.
+ *
+ * The "step_list" member points to the first element of a linked list
+ * containing the SQL statements specified as the trigger program.
+ */
+struct Trigger {
+  char *name;             /* The name of the trigger                        */
+  char *table;            /* The table or view to which the trigger applies */
+  u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
+  u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
+  Expr *pWhen;            /* The WHEN clause of the expresion (may be NULL) */
+  IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
+                             the <column-list> is stored here */
+  Token nameToken;        /* Token containing zName. Use during parsing only */
+  Schema *pSchema;        /* Schema containing the trigger */
+  Schema *pTabSchema;     /* Schema containing the table */
+  TriggerStep *step_list; /* Link list of trigger program steps             */
+  Trigger *pNext;         /* Next trigger associated with the table */
+};
+
+/*
+** A trigger is either a BEFORE or an AFTER trigger.  The following constants
+** determine which. 
+**
+** If there are multiple triggers, you might of some BEFORE and some AFTER.
+** In that cases, the constants below can be ORed together.
+*/
+#define TRIGGER_BEFORE  1
+#define TRIGGER_AFTER   2
+
+/*
+ * An instance of struct TriggerStep is used to store a single SQL statement
+ * that is a part of a trigger-program. 
+ *
+ * Instances of struct TriggerStep are stored in a singly linked list (linked
+ * using the "pNext" member) referenced by the "step_list" member of the 
+ * associated struct Trigger instance. The first element of the linked list is
+ * the first step of the trigger-program.
+ * 
+ * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
+ * "SELECT" statement. The meanings of the other members is determined by the 
+ * value of "op" as follows:
+ *
+ * (op == TK_INSERT)
+ * orconf    -> stores the ON CONFLICT algorithm
+ * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
+ *              this stores a pointer to the SELECT statement. Otherwise NULL.
+ * target    -> A token holding the name of the table to insert into.
+ * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
+ *              this stores values to be inserted. Otherwise NULL.
+ * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ... 
+ *              statement, then this stores the column-names to be
+ *              inserted into.
+ *
+ * (op == TK_DELETE)
+ * target    -> A token holding the name of the table to delete from.
+ * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
+ *              Otherwise NULL.
+ * 
+ * (op == TK_UPDATE)
+ * target    -> A token holding the name of the table to update rows of.
+ * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
+ *              Otherwise NULL.
+ * pExprList -> A list of the columns to update and the expressions to update
+ *              them to. See sqlite3Update() documentation of "pChanges"
+ *              argument.
+ * 
+ */
+struct TriggerStep {
+  int op;              /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
+  int orconf;          /* OE_Rollback etc. */
+  Trigger *pTrig;      /* The trigger that this step is a part of */
+
+  Select *pSelect;     /* Valid for SELECT and sometimes 
+                          INSERT steps (when pExprList == 0) */
+  Token target;        /* Valid for DELETE, UPDATE, INSERT steps */
+  Expr *pWhere;        /* Valid for DELETE, UPDATE steps */
+  ExprList *pExprList; /* Valid for UPDATE statements and sometimes 
+                           INSERT steps (when pSelect == 0)         */
+  IdList *pIdList;     /* Valid for INSERT statements only */
+  TriggerStep *pNext;  /* Next in the link-list */
+  TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
+};
+
+/*
+ * An instance of struct TriggerStack stores information required during code
+ * generation of a single trigger program. While the trigger program is being
+ * coded, its associated TriggerStack instance is pointed to by the
+ * "pTriggerStack" member of the Parse structure.
+ *
+ * The pTab member points to the table that triggers are being coded on. The 
+ * newIdx member contains the index of the vdbe cursor that points at the temp
+ * table that stores the new.* references. If new.* references are not valid
+ * for the trigger being coded (for example an ON DELETE trigger), then newIdx
+ * is set to -1. The oldIdx member is analogous to newIdx, for old.* references.
+ *
+ * The ON CONFLICT policy to be used for the trigger program steps is stored 
+ * as the orconf member. If this is OE_Default, then the ON CONFLICT clause 
+ * specified for individual triggers steps is used.
+ *
+ * struct TriggerStack has a "pNext" member, to allow linked lists to be
+ * constructed. When coding nested triggers (triggers fired by other triggers)
+ * each nested trigger stores its parent trigger's TriggerStack as the "pNext" 
+ * pointer. Once the nested trigger has been coded, the pNext value is restored
+ * to the pTriggerStack member of the Parse stucture and coding of the parent
+ * trigger continues.
+ *
+ * Before a nested trigger is coded, the linked list pointed to by the 
+ * pTriggerStack is scanned to ensure that the trigger is not about to be coded
+ * recursively. If this condition is detected, the nested trigger is not coded.
+ */
+struct TriggerStack {
+  Table *pTab;         /* Table that triggers are currently being coded on */
+  int newIdx;          /* Index of vdbe cursor to "new" temp table */
+  int oldIdx;          /* Index of vdbe cursor to "old" temp table */
+  u32 newColMask;
+  u32 oldColMask;
+  int orconf;          /* Current orconf policy */
+  int ignoreJump;      /* where to jump to for a RAISE(IGNORE) */
+  Trigger *pTrigger;   /* The trigger currently being coded */
+  TriggerStack *pNext; /* Next trigger down on the trigger stack */
+};
+
+/*
+** The following structure contains information used by the sqliteFix...
+** routines as they walk the parse tree to make database references
+** explicit.  
+*/
+typedef struct DbFixer DbFixer;
+struct DbFixer {
+  Parse *pParse;      /* The parsing context.  Error messages written here */
+  const char *zDb;    /* Make sure all objects are contained in this database */
+  const char *zType;  /* Type of the container - used for error messages */
+  const Token *pName; /* Name of the container - used for error messages */
+};
+
+/*
+** An objected used to accumulate the text of a string where we
+** do not necessarily know how big the string will be in the end.
+*/
+struct StrAccum {
+  sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
+  char *zBase;         /* A base allocation.  Not from malloc. */
+  char *zText;         /* The string collected so far */
+  int  nChar;          /* Length of the string so far */
+  int  nAlloc;         /* Amount of space allocated in zText */
+  int  mxAlloc;        /* Maximum allowed string length */
+  u8   mallocFailed;   /* Becomes true if any memory allocation fails */
+  u8   useMalloc;      /* True if zText is enlargable using realloc */
+  u8   tooBig;         /* Becomes true if string size exceeds limits */
+};
+
+/*
+** A pointer to this structure is used to communicate information
+** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
+*/
+typedef struct {
+  sqlite3 *db;        /* The database being initialized */
+  int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
+  char **pzErrMsg;    /* Error message stored here */
+  int rc;             /* Result code stored here */
+} InitData;
+
+/*
+** Structure containing global configuration data for the SQLite library.
+**
+** This structure also contains some state information.
+*/
+struct Sqlite3Config {
+  int bMemstat;                     /* True to enable memory status */
+  int bCoreMutex;                   /* True to enable core mutexing */
+  int bFullMutex;                   /* True to enable full mutexing */
+  int mxStrlen;                     /* Maximum string length */
+  int szLookaside;                  /* Default lookaside buffer size */
+  int nLookaside;                   /* Default lookaside buffer count */
+  sqlite3_mem_methods m;            /* Low-level memory allocation interface */
+  sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
+  void *pHeap;                      /* Heap storage space */
+  int nHeap;                        /* Size of pHeap[] */
+  int mnReq, mxReq;                 /* Min and max heap requests sizes */
+  void *pScratch;                   /* Scratch memory */
+  int szScratch;                    /* Size of each scratch buffer */
+  int nScratch;                     /* Number of scratch buffers */
+  void *pPage;                      /* Page cache memory */
+  int szPage;                       /* Size of each page in pPage[] */
+  int nPage;                        /* Number of pages in pPage[] */
+  int isInit;                       /* True after initialization has finished */
+  int isMallocInit;                 /* True after malloc is initialized */
+  sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
+  int nSmall;                       /* alloc size threshold used by mem6.c */
+  int mxParserStack;                /* maximum depth of the parser stack */
+};
+
+/*
+** Assuming zIn points to the first byte of a UTF-8 character,
+** advance zIn to point to the first byte of the next UTF-8 character.
+*/
+#define SQLITE_SKIP_UTF8(zIn) {                        \
+  if( (*(zIn++))>=0xc0 ){                              \
+    while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
+  }                                                    \
+}
+
+/*
+** The SQLITE_CORRUPT_BKPT macro can be either a constant (for production
+** builds) or a function call (for debugging).  If it is a function call,
+** it allows the operator to set a breakpoint at the spot where database
+** corruption is first detected.
+*/
+#ifdef SQLITE_DEBUG
+  int sqlite3Corrupt(void);
+# define SQLITE_CORRUPT_BKPT sqlite3Corrupt()
+#else
+# define SQLITE_CORRUPT_BKPT SQLITE_CORRUPT
+#endif
+
+/*
+** Internal function prototypes
+*/
+int sqlite3StrICmp(const char *, const char *);
+int sqlite3StrNICmp(const char *, const char *, int);
+int sqlite3IsNumber(const char*, int*, u8);
+int sqlite3Strlen(sqlite3*, const char*);
+
+int sqlite3MallocInit(void);
+void sqlite3MallocEnd(void);
+void *sqlite3Malloc(int);
+void *sqlite3MallocZero(int);
+void *sqlite3DbMallocZero(sqlite3*, int);
+void *sqlite3DbMallocRaw(sqlite3*, int);
+char *sqlite3DbStrDup(sqlite3*,const char*);
+char *sqlite3DbStrNDup(sqlite3*,const char*, int);
+void *sqlite3Realloc(void*, int);
+void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
+void *sqlite3DbRealloc(sqlite3 *, void *, int);
+void sqlite3DbFree(sqlite3*, void*);
+int sqlite3MallocSize(void*);
+int sqlite3DbMallocSize(sqlite3*, void*);
+void *sqlite3ScratchMalloc(int);
+void sqlite3ScratchFree(void*);
+void *sqlite3PageMalloc(int);
+void sqlite3PageFree(void*);
+void sqlite3MemSetDefault(void);
+const sqlite3_mem_methods *sqlite3MemGetDefault(void);
+const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
+const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
+const sqlite3_mem_methods *sqlite3MemGetMemsys6(void);
+void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
+
+#ifndef SQLITE_MUTEX_NOOP
+  sqlite3_mutex_methods *sqlite3DefaultMutex(void);
+  sqlite3_mutex *sqlite3MutexAlloc(int);
+  int sqlite3MutexInit(void);
+  int sqlite3MutexEnd(void);
+#endif
+
+void sqlite3StatusReset(void);
+int sqlite3StatusValue(int);
+void sqlite3StatusAdd(int, int);
+void sqlite3StatusSet(int, int);
+
+int sqlite3IsNaN(double);
+
+void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
+char *sqlite3MPrintf(sqlite3*,const char*, ...);
+char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
+char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
+#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
+  void sqlite3DebugPrintf(const char*, ...);
+#endif
+#if defined(SQLITE_TEST)
+  void *sqlite3TestTextToPtr(const char*);
+#endif
+void sqlite3SetString(char **, sqlite3*, const char*, ...);
+void sqlite3ErrorMsg(Parse*, const char*, ...);
+void sqlite3ErrorClear(Parse*);
+void sqlite3Dequote(char*);
+void sqlite3DequoteExpr(sqlite3*, Expr*);
+int sqlite3KeywordCode(const unsigned char*, int);
+int sqlite3RunParser(Parse*, const char*, char **);
+void sqlite3FinishCoding(Parse*);
+int sqlite3GetTempReg(Parse*);
+void sqlite3ReleaseTempReg(Parse*,int);
+int sqlite3GetTempRange(Parse*,int);
+void sqlite3ReleaseTempRange(Parse*,int,int);
+Expr *sqlite3Expr(sqlite3*, int, Expr*, Expr*, const Token*);
+Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
+Expr *sqlite3RegisterExpr(Parse*,Token*);
+Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
+void sqlite3ExprSpan(Expr*,Token*,Token*);
+Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
+void sqlite3ExprAssignVarNumber(Parse*, Expr*);
+void sqlite3ExprDelete(sqlite3*, Expr*);
+ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*,Token*);
+void sqlite3ExprListDelete(sqlite3*, ExprList*);
+int sqlite3Init(sqlite3*, char**);
+int sqlite3InitCallback(void*, int, char**, char**);
+void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
+void sqlite3ResetInternalSchema(sqlite3*, int);
+void sqlite3BeginParse(Parse*,int);
+void sqlite3CommitInternalChanges(sqlite3*);
+Table *sqlite3ResultSetOfSelect(Parse*,char*,Select*);
+void sqlite3OpenMasterTable(Parse *, int);
+void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
+void sqlite3AddColumn(Parse*,Token*);
+void sqlite3AddNotNull(Parse*, int);
+void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
+void sqlite3AddCheckConstraint(Parse*, Expr*);
+void sqlite3AddColumnType(Parse*,Token*);
+void sqlite3AddDefaultValue(Parse*,Expr*);
+void sqlite3AddCollateType(Parse*, Token*);
+void sqlite3EndTable(Parse*,Token*,Token*,Select*);
+
+Bitvec *sqlite3BitvecCreate(u32);
+int sqlite3BitvecTest(Bitvec*, u32);
+int sqlite3BitvecSet(Bitvec*, u32);
+void sqlite3BitvecClear(Bitvec*, u32);
+void sqlite3BitvecDestroy(Bitvec*);
+int sqlite3BitvecBuiltinTest(int,int*);
+
+void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
+
+#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
+  int sqlite3ViewGetColumnNames(Parse*,Table*);
+#else
+# define sqlite3ViewGetColumnNames(A,B) 0
+#endif
+
+void sqlite3DropTable(Parse*, SrcList*, int, int);
+void sqlite3DeleteTable(Table*);
+void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
+void *sqlite3ArrayAllocate(sqlite3*,void*,int,int,int*,int*,int*);
+IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
+int sqlite3IdListIndex(IdList*,const char*);
+SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
+SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*, Token*,
+                                      Select*, Expr*, IdList*);
+void sqlite3SrcListShiftJoinType(SrcList*);
+void sqlite3SrcListAssignCursors(Parse*, SrcList*);
+void sqlite3IdListDelete(sqlite3*, IdList*);
+void sqlite3SrcListDelete(sqlite3*, SrcList*);
+void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
+                        Token*, int, int);
+void sqlite3DropIndex(Parse*, SrcList*, int);
+int sqlite3Select(Parse*, Select*, SelectDest*, Select*, int, int*);
+Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
+                         Expr*,ExprList*,int,Expr*,Expr*);
+void sqlite3SelectDelete(sqlite3*, Select*);
+Table *sqlite3SrcListLookup(Parse*, SrcList*);
+int sqlite3IsReadOnly(Parse*, Table*, int);
+void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
+void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
+void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
+WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**, u8);
+void sqlite3WhereEnd(WhereInfo*);
+int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, int);
+void sqlite3ExprCodeMove(Parse*, int, int, int);
+void sqlite3ExprCodeCopy(Parse*, int, int, int);
+void sqlite3ExprClearColumnCache(Parse*, int);
+void sqlite3ExprCacheAffinityChange(Parse*, int, int);
+int sqlite3ExprWritableRegister(Parse*,int,int);
+void sqlite3ExprHardCopy(Parse*,int,int);
+int sqlite3ExprCode(Parse*, Expr*, int);
+int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
+int sqlite3ExprCodeTarget(Parse*, Expr*, int);
+int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
+void sqlite3ExprCodeConstants(Parse*, Expr*);
+int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
+void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
+void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
+Table *sqlite3FindTable(sqlite3*,const char*, const char*);
+Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
+Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
+void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
+void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
+void sqlite3Vacuum(Parse*);
+int sqlite3RunVacuum(char**, sqlite3*);
+char *sqlite3NameFromToken(sqlite3*, Token*);
+int sqlite3ExprCompare(Expr*, Expr*);
+int sqlite3ExprResolveNames(NameContext *, Expr *);
+void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
+void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
+Vdbe *sqlite3GetVdbe(Parse*);
+Expr *sqlite3CreateIdExpr(Parse *, const char*);
+void sqlite3PrngSaveState(void);
+void sqlite3PrngRestoreState(void);
+void sqlite3PrngResetState(void);
+void sqlite3RollbackAll(sqlite3*);
+void sqlite3CodeVerifySchema(Parse*, int);
+void sqlite3BeginTransaction(Parse*, int);
+void sqlite3CommitTransaction(Parse*);
+void sqlite3RollbackTransaction(Parse*);
+int sqlite3ExprIsConstant(Expr*);
+int sqlite3ExprIsConstantNotJoin(Expr*);
+int sqlite3ExprIsConstantOrFunction(Expr*);
+int sqlite3ExprIsInteger(Expr*, int*);
+int sqlite3IsRowid(const char*);
+void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int);
+void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
+int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
+void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
+                                     int*,int,int,int,int);
+void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*,int,int,int,int);
+int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
+void sqlite3BeginWriteOperation(Parse*, int, int);
+Expr *sqlite3ExprDup(sqlite3*,Expr*);
+void sqlite3TokenCopy(sqlite3*,Token*, Token*);
+ExprList *sqlite3ExprListDup(sqlite3*,ExprList*);
+SrcList *sqlite3SrcListDup(sqlite3*,SrcList*);
+IdList *sqlite3IdListDup(sqlite3*,IdList*);
+Select *sqlite3SelectDup(sqlite3*,Select*);
+FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
+void sqlite3RegisterBuiltinFunctions(sqlite3*);
+void sqlite3RegisterDateTimeFunctions(sqlite3*);
+#ifdef SQLITE_DEBUG
+  int sqlite3SafetyOn(sqlite3*);
+  int sqlite3SafetyOff(sqlite3*);
+#else
+# define sqlite3SafetyOn(A) 0
+# define sqlite3SafetyOff(A) 0
+#endif
+int sqlite3SafetyCheckOk(sqlite3*);
+int sqlite3SafetyCheckSickOrOk(sqlite3*);
+void sqlite3ChangeCookie(Parse*, int);
+void sqlite3MaterializeView(Parse*, Select*, Expr*, int);
+
+#ifndef SQLITE_OMIT_TRIGGER
+  void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
+                           Expr*,int, int);
+  void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
+  void sqlite3DropTrigger(Parse*, SrcList*, int);
+  void sqlite3DropTriggerPtr(Parse*, Trigger*);
+  int sqlite3TriggersExist(Parse*, Table*, int, ExprList*);
+  int sqlite3CodeRowTrigger(Parse*, int, ExprList*, int, Table *, int, int, 
+                           int, int, u32*, u32*);
+  void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
+  void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
+  TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
+  TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
+                                        ExprList*,Select*,int);
+  TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, int);
+  TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
+  void sqlite3DeleteTrigger(sqlite3*, Trigger*);
+  void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
+#else
+# define sqlite3TriggersExist(A,B,C,D,E,F) 0
+# define sqlite3DeleteTrigger(A,B)
+# define sqlite3DropTriggerPtr(A,B)
+# define sqlite3UnlinkAndDeleteTrigger(A,B,C)
+# define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I,J,K) 0
+#endif
+
+int sqlite3JoinType(Parse*, Token*, Token*, Token*);
+void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
+void sqlite3DeferForeignKey(Parse*, int);
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
+  int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
+  void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
+  void sqlite3AuthContextPop(AuthContext*);
+#else
+# define sqlite3AuthRead(a,b,c,d)
+# define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
+# define sqlite3AuthContextPush(a,b,c)
+# define sqlite3AuthContextPop(a)  ((void)(a))
+#endif
+void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
+void sqlite3Detach(Parse*, Expr*);
+int sqlite3BtreeFactory(const sqlite3 *db, const char *zFilename,
+                       int omitJournal, int nCache, int flags, Btree **ppBtree);
+int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
+int sqlite3FixSrcList(DbFixer*, SrcList*);
+int sqlite3FixSelect(DbFixer*, Select*);
+int sqlite3FixExpr(DbFixer*, Expr*);
+int sqlite3FixExprList(DbFixer*, ExprList*);
+int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
+int sqlite3AtoF(const char *z, double*);
+char *sqlite3_snprintf(int,char*,const char*,...);
+int sqlite3GetInt32(const char *, int*);
+int sqlite3FitsIn64Bits(const char *, int);
+int sqlite3Utf16ByteLen(const void *pData, int nChar);
+int sqlite3Utf8CharLen(const char *pData, int nByte);
+int sqlite3Utf8Read(const u8*, const u8*, const u8**);
+
+/*
+** Routines to read and write variable-length integers.  These used to
+** be defined locally, but now we use the varint routines in the util.c
+** file.  Code should use the MACRO forms below, as the Varint32 versions
+** are coded to assume the single byte case is already handled (which 
+** the MACRO form does).
+*/
+int sqlite3PutVarint(unsigned char*, u64);
+int sqlite3PutVarint32(unsigned char*, u32);
+int sqlite3GetVarint(const unsigned char *, u64 *);
+int sqlite3GetVarint32(const unsigned char *, u32 *);
+int sqlite3VarintLen(u64 v);
+
+/*
+** The header of a record consists of a sequence variable-length integers.
+** These integers are almost always small and are encoded as a single byte.
+** The following macros take advantage this fact to provide a fast encode
+** and decode of the integers in a record header.  It is faster for the common
+** case where the integer is a single byte.  It is a little slower when the
+** integer is two or more bytes.  But overall it is faster.
+**
+** The following expressions are equivalent:
+**
+**     x = sqlite3GetVarint32( A, &B );
+**     x = sqlite3PutVarint32( A, B );
+**
+**     x = getVarint32( A, B );
+**     x = putVarint32( A, B );
+**
+*/
+#define getVarint32(A,B)  ((*(A)<(unsigned char)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), &(B)))
+#define putVarint32(A,B)  (((B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
+#define getVarint    sqlite3GetVarint
+#define putVarint    sqlite3PutVarint
+
+
+void sqlite3IndexAffinityStr(Vdbe *, Index *);
+void sqlite3TableAffinityStr(Vdbe *, Table *);
+char sqlite3CompareAffinity(Expr *pExpr, char aff2);
+int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
+char sqlite3ExprAffinity(Expr *pExpr);
+int sqlite3Atoi64(const char*, i64*);
+void sqlite3Error(sqlite3*, int, const char*,...);
+void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
+int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
+const char *sqlite3ErrStr(int);
+int sqlite3ReadSchema(Parse *pParse);
+CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char *,int,int);
+CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName);
+CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
+Expr *sqlite3ExprSetColl(Parse *pParse, Expr *, Token *);
+int sqlite3CheckCollSeq(Parse *, CollSeq *);
+int sqlite3CheckObjectName(Parse *, const char *);
+void sqlite3VdbeSetChanges(sqlite3 *, int);
+
+const void *sqlite3ValueText(sqlite3_value*, u8);
+int sqlite3ValueBytes(sqlite3_value*, u8);
+void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, 
+                        void(*)(void*));
+void sqlite3ValueFree(sqlite3_value*);
+sqlite3_value *sqlite3ValueNew(sqlite3 *);
+char *sqlite3Utf16to8(sqlite3 *, const void*, int);
+int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
+void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
+#ifndef SQLITE_AMALGAMATION
+extern const unsigned char sqlite3UpperToLower[];
+extern struct Sqlite3Config sqlite3Config;
+#endif
+void sqlite3RootPageMoved(Db*, int, int);
+void sqlite3Reindex(Parse*, Token*, Token*);
+void sqlite3AlterFunctions(sqlite3*);
+void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
+int sqlite3GetToken(const unsigned char *, int *);
+void sqlite3NestedParse(Parse*, const char*, ...);
+void sqlite3ExpirePreparedStatements(sqlite3*);
+void sqlite3CodeSubselect(Parse *, Expr *, int);
+int sqlite3SelectResolve(Parse *, Select *, NameContext *);
+void sqlite3ColumnDefault(Vdbe *, Table *, int);
+void sqlite3AlterFinishAddColumn(Parse *, Token *);
+void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
+CollSeq *sqlite3GetCollSeq(sqlite3*, CollSeq *, const char *, int);
+char sqlite3AffinityType(const Token*);
+void sqlite3Analyze(Parse*, Token*, Token*);
+int sqlite3InvokeBusyHandler(BusyHandler*);
+int sqlite3FindDb(sqlite3*, Token*);
+int sqlite3AnalysisLoad(sqlite3*,int iDB);
+void sqlite3DefaultRowEst(Index*);
+void sqlite3RegisterLikeFunctions(sqlite3*, int);
+int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
+void sqlite3AttachFunctions(sqlite3 *);
+void sqlite3MinimumFileFormat(Parse*, int, int);
+void sqlite3SchemaFree(void *);
+Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
+int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
+KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
+int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *, 
+  void (*)(sqlite3_context*,int,sqlite3_value **),
+  void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
+int sqlite3ApiExit(sqlite3 *db, int);
+int sqlite3OpenTempDatabase(Parse *);
+
+void sqlite3StrAccumInit(StrAccum*, char*, int, int);
+void sqlite3StrAccumAppend(StrAccum*,const char*,int);
+char *sqlite3StrAccumFinish(StrAccum*);
+void sqlite3StrAccumReset(StrAccum*);
+void sqlite3SelectDestInit(SelectDest*,int,int);
+
+/*
+** The interface to the LEMON-generated parser
+*/
+void *sqlite3ParserAlloc(void*(*)(size_t));
+void sqlite3ParserFree(void*, void(*)(void*));
+void sqlite3Parser(void*, int, Token, Parse*);
+#ifdef YYTRACKMAXSTACKDEPTH
+  int sqlite3ParserStackPeak(void*);
+#endif
+
+int sqlite3AutoLoadExtensions(sqlite3*);
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+  void sqlite3CloseExtensions(sqlite3*);
+#else
+# define sqlite3CloseExtensions(X)
+#endif
+
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  void sqlite3TableLock(Parse *, int, int, u8, const char *);
+#else
+  #define sqlite3TableLock(v,w,x,y,z)
+#endif
+
+#ifdef SQLITE_TEST
+  int sqlite3Utf8To8(unsigned char*);
+#endif
+
+#ifdef SQLITE_OMIT_VIRTUALTABLE
+#  define sqlite3VtabClear(X)
+#  define sqlite3VtabSync(X,Y) SQLITE_OK
+#  define sqlite3VtabRollback(X)
+#  define sqlite3VtabCommit(X)
+#else
+   void sqlite3VtabClear(Table*);
+   int sqlite3VtabSync(sqlite3 *db, char **);
+   int sqlite3VtabRollback(sqlite3 *db);
+   int sqlite3VtabCommit(sqlite3 *db);
+#endif
+void sqlite3VtabMakeWritable(Parse*,Table*);
+void sqlite3VtabLock(sqlite3_vtab*);
+void sqlite3VtabUnlock(sqlite3*, sqlite3_vtab*);
+void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
+void sqlite3VtabFinishParse(Parse*, Token*);
+void sqlite3VtabArgInit(Parse*);
+void sqlite3VtabArgExtend(Parse*, Token*);
+int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
+int sqlite3VtabCallConnect(Parse*, Table*);
+int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
+int sqlite3VtabBegin(sqlite3 *, sqlite3_vtab *);
+FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
+void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
+int sqlite3Reprepare(Vdbe*);
+void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
+CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
+
+
+/*
+** Available fault injectors.  Should be numbered beginning with 0.
+*/
+#define SQLITE_FAULTINJECTOR_MALLOC     0
+#define SQLITE_FAULTINJECTOR_COUNT      1
+
+/*
+** The interface to the code in fault.c used for identifying "benign"
+** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
+** is not defined.
+*/
+#ifndef SQLITE_OMIT_BUILTIN_TEST
+  void sqlite3BeginBenignMalloc(void);
+  void sqlite3EndBenignMalloc(void);
+#else
+  #define sqlite3BeginBenignMalloc()
+  #define sqlite3EndBenignMalloc()
+#endif
+
+#define IN_INDEX_ROWID           1
+#define IN_INDEX_EPH             2
+#define IN_INDEX_INDEX           3
+int sqlite3FindInIndex(Parse *, Expr *, int*);
+
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+  int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
+  int sqlite3JournalSize(sqlite3_vfs *);
+  int sqlite3JournalCreate(sqlite3_file *);
+#else
+  #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
+#endif
+
+#if SQLITE_MAX_EXPR_DEPTH>0
+  void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
+  int sqlite3SelectExprHeight(Select *);
+#else
+  #define sqlite3ExprSetHeight(x,y)
+  #define sqlite3SelectExprHeight(x) 0
+#endif
+
+u32 sqlite3Get4byte(const u8*);
+void sqlite3Put4byte(u8*, u32);
+
+#ifdef SQLITE_SSE
+#include "sseInt.h"
+#endif
+
+#ifdef SQLITE_DEBUG
+  void sqlite3ParserTrace(FILE*, char *);
+#endif
+
+/*
+** If the SQLITE_ENABLE IOTRACE exists then the global variable
+** sqlite3IoTrace is a pointer to a printf-like routine used to
+** print I/O tracing messages. 
+*/
+#ifdef SQLITE_ENABLE_IOTRACE
+# define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
+  void sqlite3VdbeIOTraceSql(Vdbe*);
+SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
+#else
+# define IOTRACE(A)
+# define sqlite3VdbeIOTraceSql(X)
+#endif
+
+#endif
diff --git a/third_party/sqlite/src/sqliteLimit.h b/third_party/sqlite/src/sqliteLimit.h
new file mode 100755
index 0000000..a1307de
--- /dev/null
+++ b/third_party/sqlite/src/sqliteLimit.h
@@ -0,0 +1,183 @@
+/*
+** 2007 May 7
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** 
+** This file defines various limits of what SQLite can process.
+**
+** @(#) $Id: sqliteLimit.h,v 1.8 2008/03/26 15:56:22 drh Exp $
+*/
+
+/*
+** The maximum length of a TEXT or BLOB in bytes.   This also
+** limits the size of a row in a table or index.
+**
+** The hard limit is the ability of a 32-bit signed integer
+** to count the size: 2^31-1 or 2147483647.
+*/
+#ifndef SQLITE_MAX_LENGTH
+# define SQLITE_MAX_LENGTH 1000000000
+#endif
+
+/*
+** This is the maximum number of
+**
+**    * Columns in a table
+**    * Columns in an index
+**    * Columns in a view
+**    * Terms in the SET clause of an UPDATE statement
+**    * Terms in the result set of a SELECT statement
+**    * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement.
+**    * Terms in the VALUES clause of an INSERT statement
+**
+** The hard upper limit here is 32676.  Most database people will
+** tell you that in a well-normalized database, you usually should
+** not have more than a dozen or so columns in any table.  And if
+** that is the case, there is no point in having more than a few
+** dozen values in any of the other situations described above.
+*/
+#ifndef SQLITE_MAX_COLUMN
+# define SQLITE_MAX_COLUMN 2000
+#endif
+
+/*
+** The maximum length of a single SQL statement in bytes.
+**
+** It used to be the case that setting this value to zero would
+** turn the limit off.  That is no longer true.  It is not possible
+** to turn this limit off.
+*/
+#ifndef SQLITE_MAX_SQL_LENGTH
+# define SQLITE_MAX_SQL_LENGTH 1000000000
+#endif
+
+/*
+** The maximum depth of an expression tree. This is limited to 
+** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might 
+** want to place more severe limits on the complexity of an 
+** expression.
+**
+** A value of 0 used to mean that the limit was not enforced.
+** But that is no longer true.  The limit is now strictly enforced
+** at all times.
+*/
+#ifndef SQLITE_MAX_EXPR_DEPTH
+# define SQLITE_MAX_EXPR_DEPTH 1000
+#endif
+
+/*
+** The maximum number of terms in a compound SELECT statement.
+** The code generator for compound SELECT statements does one
+** level of recursion for each term.  A stack overflow can result
+** if the number of terms is too large.  In practice, most SQL
+** never has more than 3 or 4 terms.  Use a value of 0 to disable
+** any limit on the number of terms in a compount SELECT.
+*/
+#ifndef SQLITE_MAX_COMPOUND_SELECT
+# define SQLITE_MAX_COMPOUND_SELECT 500
+#endif
+
+/*
+** The maximum number of opcodes in a VDBE program.
+** Not currently enforced.
+*/
+#ifndef SQLITE_MAX_VDBE_OP
+# define SQLITE_MAX_VDBE_OP 25000
+#endif
+
+/*
+** The maximum number of arguments to an SQL function.
+*/
+#ifndef SQLITE_MAX_FUNCTION_ARG
+# define SQLITE_MAX_FUNCTION_ARG 100
+#endif
+
+/*
+** The maximum number of in-memory pages to use for the main database
+** table and for temporary tables.  The SQLITE_DEFAULT_CACHE_SIZE
+*/
+#ifndef SQLITE_DEFAULT_CACHE_SIZE
+# define SQLITE_DEFAULT_CACHE_SIZE  2000
+#endif
+#ifndef SQLITE_DEFAULT_TEMP_CACHE_SIZE
+# define SQLITE_DEFAULT_TEMP_CACHE_SIZE  500
+#endif
+
+/*
+** The maximum number of attached databases.  This must be between 0
+** and 30.  The upper bound on 30 is because a 32-bit integer bitmap
+** is used internally to track attached databases.
+*/
+#ifndef SQLITE_MAX_ATTACHED
+# define SQLITE_MAX_ATTACHED 10
+#endif
+
+
+/*
+** The maximum value of a ?nnn wildcard that the parser will accept.
+*/
+#ifndef SQLITE_MAX_VARIABLE_NUMBER
+# define SQLITE_MAX_VARIABLE_NUMBER 999
+#endif
+
+/* Maximum page size.  The upper bound on this value is 32768.  This a limit
+** imposed by the necessity of storing the value in a 2-byte unsigned integer
+** and the fact that the page size must be a power of 2.
+*/
+#ifndef SQLITE_MAX_PAGE_SIZE
+# define SQLITE_MAX_PAGE_SIZE 32768
+#endif
+
+
+/*
+** The default size of a database page.
+*/
+#ifndef SQLITE_DEFAULT_PAGE_SIZE
+# define SQLITE_DEFAULT_PAGE_SIZE 1024
+#endif
+#if SQLITE_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
+# undef SQLITE_DEFAULT_PAGE_SIZE
+# define SQLITE_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE
+#endif
+
+/*
+** Ordinarily, if no value is explicitly provided, SQLite creates databases
+** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain
+** device characteristics (sector-size and atomic write() support),
+** SQLite may choose a larger value. This constant is the maximum value
+** SQLite will choose on its own.
+*/
+#ifndef SQLITE_MAX_DEFAULT_PAGE_SIZE
+# define SQLITE_MAX_DEFAULT_PAGE_SIZE 8192
+#endif
+#if SQLITE_MAX_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
+# undef SQLITE_MAX_DEFAULT_PAGE_SIZE
+# define SQLITE_MAX_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE
+#endif
+
+
+/*
+** Maximum number of pages in one database file.
+**
+** This is really just the default value for the max_page_count pragma.
+** This value can be lowered (or raised) at run-time using that the
+** max_page_count macro.
+*/
+#ifndef SQLITE_MAX_PAGE_COUNT
+# define SQLITE_MAX_PAGE_COUNT 1073741823
+#endif
+
+/*
+** Maximum length (in bytes) of the pattern in a LIKE or GLOB
+** operator.
+*/
+#ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH
+# define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000
+#endif
diff --git a/third_party/sqlite/src/status.c b/third_party/sqlite/src/status.c
new file mode 100755
index 0000000..a60a853
--- /dev/null
+++ b/third_party/sqlite/src/status.c
@@ -0,0 +1,111 @@
+/*
+** 2008 June 18
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This module implements the sqlite3_status() interface and related
+** functionality.
+**
+** $Id: status.c,v 1.7 2008/08/05 17:53:23 drh Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** Variables in which to record status information.
+*/
+static struct {
+  int nowValue[9];         /* Current value */
+  int mxValue[9];          /* Maximum value */
+} sqlite3Stat;
+
+
+/*
+** Reset the status records.  This routine is called by
+** sqlite3_initialize().
+*/
+void sqlite3StatusReset(void){
+  memset(&sqlite3Stat, 0, sizeof(sqlite3Stat));
+}
+
+/*
+** Return the current value of a status parameter.
+*/
+int sqlite3StatusValue(int op){
+  assert( op>=0 && op<ArraySize(sqlite3Stat.nowValue) );
+  return sqlite3Stat.nowValue[op];
+}
+
+/*
+** Add N to the value of a status record.  It is assumed that the
+** caller holds appropriate locks.
+*/
+void sqlite3StatusAdd(int op, int N){
+  assert( op>=0 && op<ArraySize(sqlite3Stat.nowValue) );
+  sqlite3Stat.nowValue[op] += N;
+  if( sqlite3Stat.nowValue[op]>sqlite3Stat.mxValue[op] ){
+    sqlite3Stat.mxValue[op] = sqlite3Stat.nowValue[op];
+  }
+}
+
+/*
+** Set the value of a status to X.
+*/
+void sqlite3StatusSet(int op, int X){
+  assert( op>=0 && op<ArraySize(sqlite3Stat.nowValue) );
+  sqlite3Stat.nowValue[op] = X;
+  if( sqlite3Stat.nowValue[op]>sqlite3Stat.mxValue[op] ){
+    sqlite3Stat.mxValue[op] = sqlite3Stat.nowValue[op];
+  }
+}
+
+/*
+** Query status information.
+**
+** This implementation assumes that reading or writing an aligned
+** 32-bit integer is an atomic operation.  If that assumption is not true,
+** then this routine is not threadsafe.
+*/
+int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
+  if( op<0 || op>=ArraySize(sqlite3Stat.nowValue) ){
+    return SQLITE_MISUSE;
+  }
+  *pCurrent = sqlite3Stat.nowValue[op];
+  *pHighwater = sqlite3Stat.mxValue[op];
+  if( resetFlag ){
+    sqlite3Stat.mxValue[op] = sqlite3Stat.nowValue[op];
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Query status information for a single database connection
+*/
+int sqlite3_db_status(
+  sqlite3 *db,          /* The database connection whose status is desired */
+  int op,               /* Status verb */
+  int *pCurrent,        /* Write current value here */
+  int *pHighwater,      /* Write high-water mark here */
+  int resetFlag         /* Reset high-water mark if true */
+){
+  switch( op ){
+    case SQLITE_DBSTATUS_LOOKASIDE_USED: {
+      *pCurrent = db->lookaside.nOut;
+      *pHighwater = db->lookaside.mxOut;
+      if( resetFlag ){
+        db->lookaside.mxOut = db->lookaside.nOut;
+      }
+      break;
+    }
+    default: {
+      return SQLITE_ERROR;
+    }
+  }
+  return SQLITE_OK;
+}
diff --git a/third_party/sqlite/src/table.c b/third_party/sqlite/src/table.c
new file mode 100755
index 0000000..1bd1bd1
--- /dev/null
+++ b/third_party/sqlite/src/table.c
@@ -0,0 +1,201 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the sqlite3_get_table() and sqlite3_free_table()
+** interface routines.  These are just wrappers around the main
+** interface routine of sqlite3_exec().
+**
+** These routines are in a separate files so that they will not be linked
+** if they are not used.
+**
+** $Id: table.c,v 1.36 2008/07/08 22:28:49 shane Exp $
+*/
+#include "sqliteInt.h"
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef SQLITE_OMIT_GET_TABLE
+
+/*
+** This structure is used to pass data from sqlite3_get_table() through
+** to the callback function is uses to build the result.
+*/
+typedef struct TabResult {
+  char **azResult;
+  char *zErrMsg;
+  int nResult;
+  int nAlloc;
+  int nRow;
+  int nColumn;
+  int nData;
+  int rc;
+} TabResult;
+
+/*
+** This routine is called once for each row in the result table.  Its job
+** is to fill in the TabResult structure appropriately, allocating new
+** memory as necessary.
+*/
+static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
+  TabResult *p = (TabResult*)pArg;
+  int need;
+  int i;
+  char *z;
+
+  /* Make sure there is enough space in p->azResult to hold everything
+  ** we need to remember from this invocation of the callback.
+  */
+  if( p->nRow==0 && argv!=0 ){
+    need = nCol*2;
+  }else{
+    need = nCol;
+  }
+  if( p->nData + need >= p->nAlloc ){
+    char **azNew;
+    p->nAlloc = p->nAlloc*2 + need + 1;
+    azNew = sqlite3_realloc( p->azResult, sizeof(char*)*p->nAlloc );
+    if( azNew==0 ) goto malloc_failed;
+    p->azResult = azNew;
+  }
+
+  /* If this is the first row, then generate an extra row containing
+  ** the names of all columns.
+  */
+  if( p->nRow==0 ){
+    p->nColumn = nCol;
+    for(i=0; i<nCol; i++){
+      z = sqlite3_mprintf("%s", colv[i]);
+      if( z==0 ) goto malloc_failed;
+      p->azResult[p->nData++] = z;
+    }
+  }else if( p->nColumn!=nCol ){
+    sqlite3_free(p->zErrMsg);
+    p->zErrMsg = sqlite3_mprintf(
+       "sqlite3_get_table() called with two or more incompatible queries"
+    );
+    p->rc = SQLITE_ERROR;
+    return 1;
+  }
+
+  /* Copy over the row data
+  */
+  if( argv!=0 ){
+    for(i=0; i<nCol; i++){
+      if( argv[i]==0 ){
+        z = 0;
+      }else{
+        int n = strlen(argv[i])+1;
+        z = sqlite3_malloc( n );
+        if( z==0 ) goto malloc_failed;
+        memcpy(z, argv[i], n);
+      }
+      p->azResult[p->nData++] = z;
+    }
+    p->nRow++;
+  }
+  return 0;
+
+malloc_failed:
+  p->rc = SQLITE_NOMEM;
+  return 1;
+}
+
+/*
+** Query the database.  But instead of invoking a callback for each row,
+** malloc() for space to hold the result and return the entire results
+** at the conclusion of the call.
+**
+** The result that is written to ***pazResult is held in memory obtained
+** from malloc().  But the caller cannot free this memory directly.  
+** Instead, the entire table should be passed to sqlite3_free_table() when
+** the calling procedure is finished using it.
+*/
+int sqlite3_get_table(
+  sqlite3 *db,                /* The database on which the SQL executes */
+  const char *zSql,           /* The SQL to be executed */
+  char ***pazResult,          /* Write the result table here */
+  int *pnRow,                 /* Write the number of rows in the result here */
+  int *pnColumn,              /* Write the number of columns of result here */
+  char **pzErrMsg             /* Write error messages here */
+){
+  int rc;
+  TabResult res;
+
+  *pazResult = 0;
+  if( pnColumn ) *pnColumn = 0;
+  if( pnRow ) *pnRow = 0;
+  res.zErrMsg = 0;
+  res.nResult = 0;
+  res.nRow = 0;
+  res.nColumn = 0;
+  res.nData = 1;
+  res.nAlloc = 20;
+  res.rc = SQLITE_OK;
+  res.azResult = sqlite3_malloc(sizeof(char*)*res.nAlloc );
+  if( res.azResult==0 ){
+     db->errCode = SQLITE_NOMEM;
+     return SQLITE_NOMEM;
+  }
+  res.azResult[0] = 0;
+  rc = sqlite3_exec(db, zSql, sqlite3_get_table_cb, &res, pzErrMsg);
+  assert( sizeof(res.azResult[0])>= sizeof(res.nData) );
+  res.azResult[0] = SQLITE_INT_TO_PTR(res.nData);
+  if( (rc&0xff)==SQLITE_ABORT ){
+    sqlite3_free_table(&res.azResult[1]);
+    if( res.zErrMsg ){
+      if( pzErrMsg ){
+        sqlite3_free(*pzErrMsg);
+        *pzErrMsg = sqlite3_mprintf("%s",res.zErrMsg);
+      }
+      sqlite3_free(res.zErrMsg);
+    }
+    db->errCode = res.rc;  /* Assume 32-bit assignment is atomic */
+    return res.rc;
+  }
+  sqlite3_free(res.zErrMsg);
+  if( rc!=SQLITE_OK ){
+    sqlite3_free_table(&res.azResult[1]);
+    return rc;
+  }
+  if( res.nAlloc>res.nData ){
+    char **azNew;
+    azNew = sqlite3_realloc( res.azResult, sizeof(char*)*(res.nData+1) );
+    if( azNew==0 ){
+      sqlite3_free_table(&res.azResult[1]);
+      db->errCode = SQLITE_NOMEM;
+      return SQLITE_NOMEM;
+    }
+    res.nAlloc = res.nData+1;
+    res.azResult = azNew;
+  }
+  *pazResult = &res.azResult[1];
+  if( pnColumn ) *pnColumn = res.nColumn;
+  if( pnRow ) *pnRow = res.nRow;
+  return rc;
+}
+
+/*
+** This routine frees the space the sqlite3_get_table() malloced.
+*/
+void sqlite3_free_table(
+  char **azResult            /* Result returned from from sqlite3_get_table() */
+){
+  if( azResult ){
+    int i, n;
+    azResult--;
+    assert( azResult!=0 );
+    n = SQLITE_PTR_TO_INT(azResult[0]);
+    for(i=1; i<n; i++){ if( azResult[i] ) sqlite3_free(azResult[i]); }
+    sqlite3_free(azResult);
+  }
+}
+
+#endif /* SQLITE_OMIT_GET_TABLE */
diff --git a/third_party/sqlite/src/tclsqlite.c b/third_party/sqlite/src/tclsqlite.c
new file mode 100755
index 0000000..35a69b8
--- /dev/null
+++ b/third_party/sqlite/src/tclsqlite.c
@@ -0,0 +1,2599 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** A TCL Interface to SQLite.  Append this file to sqlite3.c and
+** compile the whole thing to build a TCL-enabled version of SQLite.
+**
+** $Id: tclsqlite.c,v 1.219 2008/07/10 17:52:49 danielk1977 Exp $
+*/
+#include "tcl.h"
+#include <errno.h>
+
+/*
+** Some additional include files are needed if this file is not
+** appended to the amalgamation.
+*/
+#ifndef SQLITE_AMALGAMATION
+# include "sqliteInt.h"
+# include <stdlib.h>
+# include <string.h>
+# include <assert.h>
+# include <ctype.h>
+#endif
+
+/*
+ * Windows needs to know which symbols to export.  Unix does not.
+ * BUILD_sqlite should be undefined for Unix.
+ */
+#ifdef BUILD_sqlite
+#undef TCL_STORAGE_CLASS
+#define TCL_STORAGE_CLASS DLLEXPORT
+#endif /* BUILD_sqlite */
+
+#define NUM_PREPARED_STMTS 10
+#define MAX_PREPARED_STMTS 100
+
+/*
+** If TCL uses UTF-8 and SQLite is configured to use iso8859, then we
+** have to do a translation when going between the two.  Set the 
+** UTF_TRANSLATION_NEEDED macro to indicate that we need to do
+** this translation.  
+*/
+#if defined(TCL_UTF_MAX) && !defined(SQLITE_UTF8)
+# define UTF_TRANSLATION_NEEDED 1
+#endif
+
+/*
+** New SQL functions can be created as TCL scripts.  Each such function
+** is described by an instance of the following structure.
+*/
+typedef struct SqlFunc SqlFunc;
+struct SqlFunc {
+  Tcl_Interp *interp;   /* The TCL interpret to execute the function */
+  Tcl_Obj *pScript;     /* The Tcl_Obj representation of the script */
+  int useEvalObjv;      /* True if it is safe to use Tcl_EvalObjv */
+  char *zName;          /* Name of this function */
+  SqlFunc *pNext;       /* Next function on the list of them all */
+};
+
+/*
+** New collation sequences function can be created as TCL scripts.  Each such
+** function is described by an instance of the following structure.
+*/
+typedef struct SqlCollate SqlCollate;
+struct SqlCollate {
+  Tcl_Interp *interp;   /* The TCL interpret to execute the function */
+  char *zScript;        /* The script to be run */
+  SqlCollate *pNext;    /* Next function on the list of them all */
+};
+
+/*
+** Prepared statements are cached for faster execution.  Each prepared
+** statement is described by an instance of the following structure.
+*/
+typedef struct SqlPreparedStmt SqlPreparedStmt;
+struct SqlPreparedStmt {
+  SqlPreparedStmt *pNext;  /* Next in linked list */
+  SqlPreparedStmt *pPrev;  /* Previous on the list */
+  sqlite3_stmt *pStmt;     /* The prepared statement */
+  int nSql;                /* chars in zSql[] */
+  const char *zSql;        /* Text of the SQL statement */
+};
+
+typedef struct IncrblobChannel IncrblobChannel;
+
+/*
+** There is one instance of this structure for each SQLite database
+** that has been opened by the SQLite TCL interface.
+*/
+typedef struct SqliteDb SqliteDb;
+struct SqliteDb {
+  sqlite3 *db;               /* The "real" database structure. MUST BE FIRST */
+  Tcl_Interp *interp;        /* The interpreter used for this database */
+  char *zBusy;               /* The busy callback routine */
+  char *zCommit;             /* The commit hook callback routine */
+  char *zTrace;              /* The trace callback routine */
+  char *zProfile;            /* The profile callback routine */
+  char *zProgress;           /* The progress callback routine */
+  char *zAuth;               /* The authorization callback routine */
+  char *zNull;               /* Text to substitute for an SQL NULL value */
+  SqlFunc *pFunc;            /* List of SQL functions */
+  Tcl_Obj *pUpdateHook;      /* Update hook script (if any) */
+  Tcl_Obj *pRollbackHook;    /* Rollback hook script (if any) */
+  SqlCollate *pCollate;      /* List of SQL collation functions */
+  int rc;                    /* Return code of most recent sqlite3_exec() */
+  Tcl_Obj *pCollateNeeded;   /* Collation needed script */
+  SqlPreparedStmt *stmtList; /* List of prepared statements*/
+  SqlPreparedStmt *stmtLast; /* Last statement in the list */
+  int maxStmt;               /* The next maximum number of stmtList */
+  int nStmt;                 /* Number of statements in stmtList */
+  IncrblobChannel *pIncrblob;/* Linked list of open incrblob channels */
+};
+
+struct IncrblobChannel {
+  sqlite3_blob *pBlob;      /* sqlite3 blob handle */
+  SqliteDb *pDb;            /* Associated database connection */
+  int iSeek;                /* Current seek offset */
+  Tcl_Channel channel;      /* Channel identifier */
+  IncrblobChannel *pNext;   /* Linked list of all open incrblob channels */
+  IncrblobChannel *pPrev;   /* Linked list of all open incrblob channels */
+};
+
+#ifndef SQLITE_OMIT_INCRBLOB
+/*
+** Close all incrblob channels opened using database connection pDb.
+** This is called when shutting down the database connection.
+*/
+static void closeIncrblobChannels(SqliteDb *pDb){
+  IncrblobChannel *p;
+  IncrblobChannel *pNext;
+
+  for(p=pDb->pIncrblob; p; p=pNext){
+    pNext = p->pNext;
+
+    /* Note: Calling unregister here call Tcl_Close on the incrblob channel, 
+    ** which deletes the IncrblobChannel structure at *p. So do not
+    ** call Tcl_Free() here.
+    */
+    Tcl_UnregisterChannel(pDb->interp, p->channel);
+  }
+}
+
+/*
+** Close an incremental blob channel.
+*/
+static int incrblobClose(ClientData instanceData, Tcl_Interp *interp){
+  IncrblobChannel *p = (IncrblobChannel *)instanceData;
+  int rc = sqlite3_blob_close(p->pBlob);
+  sqlite3 *db = p->pDb->db;
+
+  /* Remove the channel from the SqliteDb.pIncrblob list. */
+  if( p->pNext ){
+    p->pNext->pPrev = p->pPrev;
+  }
+  if( p->pPrev ){
+    p->pPrev->pNext = p->pNext;
+  }
+  if( p->pDb->pIncrblob==p ){
+    p->pDb->pIncrblob = p->pNext;
+  }
+
+  /* Free the IncrblobChannel structure */
+  Tcl_Free((char *)p);
+
+  if( rc!=SQLITE_OK ){
+    Tcl_SetResult(interp, (char *)sqlite3_errmsg(db), TCL_VOLATILE);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Read data from an incremental blob channel.
+*/
+static int incrblobInput(
+  ClientData instanceData, 
+  char *buf, 
+  int bufSize,
+  int *errorCodePtr
+){
+  IncrblobChannel *p = (IncrblobChannel *)instanceData;
+  int nRead = bufSize;         /* Number of bytes to read */
+  int nBlob;                   /* Total size of the blob */
+  int rc;                      /* sqlite error code */
+
+  nBlob = sqlite3_blob_bytes(p->pBlob);
+  if( (p->iSeek+nRead)>nBlob ){
+    nRead = nBlob-p->iSeek;
+  }
+  if( nRead<=0 ){
+    return 0;
+  }
+
+  rc = sqlite3_blob_read(p->pBlob, (void *)buf, nRead, p->iSeek);
+  if( rc!=SQLITE_OK ){
+    *errorCodePtr = rc;
+    return -1;
+  }
+
+  p->iSeek += nRead;
+  return nRead;
+}
+
+/*
+** Write data to an incremental blob channel.
+*/
+static int incrblobOutput(
+  ClientData instanceData, 
+  CONST char *buf, 
+  int toWrite,
+  int *errorCodePtr
+){
+  IncrblobChannel *p = (IncrblobChannel *)instanceData;
+  int nWrite = toWrite;        /* Number of bytes to write */
+  int nBlob;                   /* Total size of the blob */
+  int rc;                      /* sqlite error code */
+
+  nBlob = sqlite3_blob_bytes(p->pBlob);
+  if( (p->iSeek+nWrite)>nBlob ){
+    *errorCodePtr = EINVAL;
+    return -1;
+  }
+  if( nWrite<=0 ){
+    return 0;
+  }
+
+  rc = sqlite3_blob_write(p->pBlob, (void *)buf, nWrite, p->iSeek);
+  if( rc!=SQLITE_OK ){
+    *errorCodePtr = EIO;
+    return -1;
+  }
+
+  p->iSeek += nWrite;
+  return nWrite;
+}
+
+/*
+** Seek an incremental blob channel.
+*/
+static int incrblobSeek(
+  ClientData instanceData, 
+  long offset,
+  int seekMode,
+  int *errorCodePtr
+){
+  IncrblobChannel *p = (IncrblobChannel *)instanceData;
+
+  switch( seekMode ){
+    case SEEK_SET:
+      p->iSeek = offset;
+      break;
+    case SEEK_CUR:
+      p->iSeek += offset;
+      break;
+    case SEEK_END:
+      p->iSeek = sqlite3_blob_bytes(p->pBlob) + offset;
+      break;
+
+    default: assert(!"Bad seekMode");
+  }
+
+  return p->iSeek;
+}
+
+
+static void incrblobWatch(ClientData instanceData, int mode){ 
+  /* NO-OP */ 
+}
+static int incrblobHandle(ClientData instanceData, int dir, ClientData *hPtr){
+  return TCL_ERROR;
+}
+
+static Tcl_ChannelType IncrblobChannelType = {
+  "incrblob",                        /* typeName                             */
+  TCL_CHANNEL_VERSION_2,             /* version                              */
+  incrblobClose,                     /* closeProc                            */
+  incrblobInput,                     /* inputProc                            */
+  incrblobOutput,                    /* outputProc                           */
+  incrblobSeek,                      /* seekProc                             */
+  0,                                 /* setOptionProc                        */
+  0,                                 /* getOptionProc                        */
+  incrblobWatch,                     /* watchProc (this is a no-op)          */
+  incrblobHandle,                    /* getHandleProc (always returns error) */
+  0,                                 /* close2Proc                           */
+  0,                                 /* blockModeProc                        */
+  0,                                 /* flushProc                            */
+  0,                                 /* handlerProc                          */
+  0,                                 /* wideSeekProc                         */
+};
+
+/*
+** Create a new incrblob channel.
+*/
+static int createIncrblobChannel(
+  Tcl_Interp *interp, 
+  SqliteDb *pDb, 
+  const char *zDb,
+  const char *zTable, 
+  const char *zColumn, 
+  sqlite_int64 iRow,
+  int isReadonly
+){
+  IncrblobChannel *p;
+  sqlite3 *db = pDb->db;
+  sqlite3_blob *pBlob;
+  int rc;
+  int flags = TCL_READABLE|(isReadonly ? 0 : TCL_WRITABLE);
+
+  /* This variable is used to name the channels: "incrblob_[incr count]" */
+  static int count = 0;
+  char zChannel[64];
+
+  rc = sqlite3_blob_open(db, zDb, zTable, zColumn, iRow, !isReadonly, &pBlob);
+  if( rc!=SQLITE_OK ){
+    Tcl_SetResult(interp, (char *)sqlite3_errmsg(pDb->db), TCL_VOLATILE);
+    return TCL_ERROR;
+  }
+
+  p = (IncrblobChannel *)Tcl_Alloc(sizeof(IncrblobChannel));
+  p->iSeek = 0;
+  p->pBlob = pBlob;
+
+  sqlite3_snprintf(sizeof(zChannel), zChannel, "incrblob_%d", ++count);
+  p->channel = Tcl_CreateChannel(&IncrblobChannelType, zChannel, p, flags);
+  Tcl_RegisterChannel(interp, p->channel);
+
+  /* Link the new channel into the SqliteDb.pIncrblob list. */
+  p->pNext = pDb->pIncrblob;
+  p->pPrev = 0;
+  if( p->pNext ){
+    p->pNext->pPrev = p;
+  }
+  pDb->pIncrblob = p;
+  p->pDb = pDb;
+
+  Tcl_SetResult(interp, (char *)Tcl_GetChannelName(p->channel), TCL_VOLATILE);
+  return TCL_OK;
+}
+#else  /* else clause for "#ifndef SQLITE_OMIT_INCRBLOB" */
+  #define closeIncrblobChannels(pDb)
+#endif
+
+/*
+** Look at the script prefix in pCmd.  We will be executing this script
+** after first appending one or more arguments.  This routine analyzes
+** the script to see if it is safe to use Tcl_EvalObjv() on the script
+** rather than the more general Tcl_EvalEx().  Tcl_EvalObjv() is much
+** faster.
+**
+** Scripts that are safe to use with Tcl_EvalObjv() consists of a
+** command name followed by zero or more arguments with no [...] or $
+** or {...} or ; to be seen anywhere.  Most callback scripts consist
+** of just a single procedure name and they meet this requirement.
+*/
+static int safeToUseEvalObjv(Tcl_Interp *interp, Tcl_Obj *pCmd){
+  /* We could try to do something with Tcl_Parse().  But we will instead
+  ** just do a search for forbidden characters.  If any of the forbidden
+  ** characters appear in pCmd, we will report the string as unsafe.
+  */
+  const char *z;
+  int n;
+  z = Tcl_GetStringFromObj(pCmd, &n);
+  while( n-- > 0 ){
+    int c = *(z++);
+    if( c=='$' || c=='[' || c==';' ) return 0;
+  }
+  return 1;
+}
+
+/*
+** Find an SqlFunc structure with the given name.  Or create a new
+** one if an existing one cannot be found.  Return a pointer to the
+** structure.
+*/
+static SqlFunc *findSqlFunc(SqliteDb *pDb, const char *zName){
+  SqlFunc *p, *pNew;
+  int i;
+  pNew = (SqlFunc*)Tcl_Alloc( sizeof(*pNew) + strlen(zName) + 1 );
+  pNew->zName = (char*)&pNew[1];
+  for(i=0; zName[i]; i++){ pNew->zName[i] = tolower(zName[i]); }
+  pNew->zName[i] = 0;
+  for(p=pDb->pFunc; p; p=p->pNext){ 
+    if( strcmp(p->zName, pNew->zName)==0 ){
+      Tcl_Free((char*)pNew);
+      return p;
+    }
+  }
+  pNew->interp = pDb->interp;
+  pNew->pScript = 0;
+  pNew->pNext = pDb->pFunc;
+  pDb->pFunc = pNew;
+  return pNew;
+}
+
+/*
+** Finalize and free a list of prepared statements
+*/
+static void flushStmtCache( SqliteDb *pDb ){
+  SqlPreparedStmt *pPreStmt;
+
+  while(  pDb->stmtList ){
+    sqlite3_finalize( pDb->stmtList->pStmt );
+    pPreStmt = pDb->stmtList;
+    pDb->stmtList = pDb->stmtList->pNext;
+    Tcl_Free( (char*)pPreStmt );
+  }
+  pDb->nStmt = 0;
+  pDb->stmtLast = 0;
+}
+
+/*
+** TCL calls this procedure when an sqlite3 database command is
+** deleted.
+*/
+static void DbDeleteCmd(void *db){
+  SqliteDb *pDb = (SqliteDb*)db;
+  flushStmtCache(pDb);
+  closeIncrblobChannels(pDb);
+  sqlite3_close(pDb->db);
+  while( pDb->pFunc ){
+    SqlFunc *pFunc = pDb->pFunc;
+    pDb->pFunc = pFunc->pNext;
+    Tcl_DecrRefCount(pFunc->pScript);
+    Tcl_Free((char*)pFunc);
+  }
+  while( pDb->pCollate ){
+    SqlCollate *pCollate = pDb->pCollate;
+    pDb->pCollate = pCollate->pNext;
+    Tcl_Free((char*)pCollate);
+  }
+  if( pDb->zBusy ){
+    Tcl_Free(pDb->zBusy);
+  }
+  if( pDb->zTrace ){
+    Tcl_Free(pDb->zTrace);
+  }
+  if( pDb->zProfile ){
+    Tcl_Free(pDb->zProfile);
+  }
+  if( pDb->zAuth ){
+    Tcl_Free(pDb->zAuth);
+  }
+  if( pDb->zNull ){
+    Tcl_Free(pDb->zNull);
+  }
+  if( pDb->pUpdateHook ){
+    Tcl_DecrRefCount(pDb->pUpdateHook);
+  }
+  if( pDb->pRollbackHook ){
+    Tcl_DecrRefCount(pDb->pRollbackHook);
+  }
+  if( pDb->pCollateNeeded ){
+    Tcl_DecrRefCount(pDb->pCollateNeeded);
+  }
+  Tcl_Free((char*)pDb);
+}
+
+/*
+** This routine is called when a database file is locked while trying
+** to execute SQL.
+*/
+static int DbBusyHandler(void *cd, int nTries){
+  SqliteDb *pDb = (SqliteDb*)cd;
+  int rc;
+  char zVal[30];
+
+  sqlite3_snprintf(sizeof(zVal), zVal, "%d", nTries);
+  rc = Tcl_VarEval(pDb->interp, pDb->zBusy, " ", zVal, (char*)0);
+  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
+    return 0;
+  }
+  return 1;
+}
+
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+/*
+** This routine is invoked as the 'progress callback' for the database.
+*/
+static int DbProgressHandler(void *cd){
+  SqliteDb *pDb = (SqliteDb*)cd;
+  int rc;
+
+  assert( pDb->zProgress );
+  rc = Tcl_Eval(pDb->interp, pDb->zProgress);
+  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
+    return 1;
+  }
+  return 0;
+}
+#endif
+
+#ifndef SQLITE_OMIT_TRACE
+/*
+** This routine is called by the SQLite trace handler whenever a new
+** block of SQL is executed.  The TCL script in pDb->zTrace is executed.
+*/
+static void DbTraceHandler(void *cd, const char *zSql){
+  SqliteDb *pDb = (SqliteDb*)cd;
+  Tcl_DString str;
+
+  Tcl_DStringInit(&str);
+  Tcl_DStringAppend(&str, pDb->zTrace, -1);
+  Tcl_DStringAppendElement(&str, zSql);
+  Tcl_Eval(pDb->interp, Tcl_DStringValue(&str));
+  Tcl_DStringFree(&str);
+  Tcl_ResetResult(pDb->interp);
+}
+#endif
+
+#ifndef SQLITE_OMIT_TRACE
+/*
+** This routine is called by the SQLite profile handler after a statement
+** SQL has executed.  The TCL script in pDb->zProfile is evaluated.
+*/
+static void DbProfileHandler(void *cd, const char *zSql, sqlite_uint64 tm){
+  SqliteDb *pDb = (SqliteDb*)cd;
+  Tcl_DString str;
+  char zTm[100];
+
+  sqlite3_snprintf(sizeof(zTm)-1, zTm, "%lld", tm);
+  Tcl_DStringInit(&str);
+  Tcl_DStringAppend(&str, pDb->zProfile, -1);
+  Tcl_DStringAppendElement(&str, zSql);
+  Tcl_DStringAppendElement(&str, zTm);
+  Tcl_Eval(pDb->interp, Tcl_DStringValue(&str));
+  Tcl_DStringFree(&str);
+  Tcl_ResetResult(pDb->interp);
+}
+#endif
+
+/*
+** This routine is called when a transaction is committed.  The
+** TCL script in pDb->zCommit is executed.  If it returns non-zero or
+** if it throws an exception, the transaction is rolled back instead
+** of being committed.
+*/
+static int DbCommitHandler(void *cd){
+  SqliteDb *pDb = (SqliteDb*)cd;
+  int rc;
+
+  rc = Tcl_Eval(pDb->interp, pDb->zCommit);
+  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
+    return 1;
+  }
+  return 0;
+}
+
+static void DbRollbackHandler(void *clientData){
+  SqliteDb *pDb = (SqliteDb*)clientData;
+  assert(pDb->pRollbackHook);
+  if( TCL_OK!=Tcl_EvalObjEx(pDb->interp, pDb->pRollbackHook, 0) ){
+    Tcl_BackgroundError(pDb->interp);
+  }
+}
+
+static void DbUpdateHandler(
+  void *p, 
+  int op,
+  const char *zDb, 
+  const char *zTbl, 
+  sqlite_int64 rowid
+){
+  SqliteDb *pDb = (SqliteDb *)p;
+  Tcl_Obj *pCmd;
+
+  assert( pDb->pUpdateHook );
+  assert( op==SQLITE_INSERT || op==SQLITE_UPDATE || op==SQLITE_DELETE );
+
+  pCmd = Tcl_DuplicateObj(pDb->pUpdateHook);
+  Tcl_IncrRefCount(pCmd);
+  Tcl_ListObjAppendElement(0, pCmd, Tcl_NewStringObj(
+    ( (op==SQLITE_INSERT)?"INSERT":(op==SQLITE_UPDATE)?"UPDATE":"DELETE"), -1));
+  Tcl_ListObjAppendElement(0, pCmd, Tcl_NewStringObj(zDb, -1));
+  Tcl_ListObjAppendElement(0, pCmd, Tcl_NewStringObj(zTbl, -1));
+  Tcl_ListObjAppendElement(0, pCmd, Tcl_NewWideIntObj(rowid));
+  Tcl_EvalObjEx(pDb->interp, pCmd, TCL_EVAL_DIRECT);
+}
+
+static void tclCollateNeeded(
+  void *pCtx,
+  sqlite3 *db,
+  int enc,
+  const char *zName
+){
+  SqliteDb *pDb = (SqliteDb *)pCtx;
+  Tcl_Obj *pScript = Tcl_DuplicateObj(pDb->pCollateNeeded);
+  Tcl_IncrRefCount(pScript);
+  Tcl_ListObjAppendElement(0, pScript, Tcl_NewStringObj(zName, -1));
+  Tcl_EvalObjEx(pDb->interp, pScript, 0);
+  Tcl_DecrRefCount(pScript);
+}
+
+/*
+** This routine is called to evaluate an SQL collation function implemented
+** using TCL script.
+*/
+static int tclSqlCollate(
+  void *pCtx,
+  int nA,
+  const void *zA,
+  int nB,
+  const void *zB
+){
+  SqlCollate *p = (SqlCollate *)pCtx;
+  Tcl_Obj *pCmd;
+
+  pCmd = Tcl_NewStringObj(p->zScript, -1);
+  Tcl_IncrRefCount(pCmd);
+  Tcl_ListObjAppendElement(p->interp, pCmd, Tcl_NewStringObj(zA, nA));
+  Tcl_ListObjAppendElement(p->interp, pCmd, Tcl_NewStringObj(zB, nB));
+  Tcl_EvalObjEx(p->interp, pCmd, TCL_EVAL_DIRECT);
+  Tcl_DecrRefCount(pCmd);
+  return (atoi(Tcl_GetStringResult(p->interp)));
+}
+
+/*
+** This routine is called to evaluate an SQL function implemented
+** using TCL script.
+*/
+static void tclSqlFunc(sqlite3_context *context, int argc, sqlite3_value**argv){
+  SqlFunc *p = sqlite3_user_data(context);
+  Tcl_Obj *pCmd;
+  int i;
+  int rc;
+
+  if( argc==0 ){
+    /* If there are no arguments to the function, call Tcl_EvalObjEx on the
+    ** script object directly.  This allows the TCL compiler to generate
+    ** bytecode for the command on the first invocation and thus make
+    ** subsequent invocations much faster. */
+    pCmd = p->pScript;
+    Tcl_IncrRefCount(pCmd);
+    rc = Tcl_EvalObjEx(p->interp, pCmd, 0);
+    Tcl_DecrRefCount(pCmd);
+  }else{
+    /* If there are arguments to the function, make a shallow copy of the
+    ** script object, lappend the arguments, then evaluate the copy.
+    **
+    ** By "shallow" copy, we mean a only the outer list Tcl_Obj is duplicated.
+    ** The new Tcl_Obj contains pointers to the original list elements. 
+    ** That way, when Tcl_EvalObjv() is run and shimmers the first element
+    ** of the list to tclCmdNameType, that alternate representation will
+    ** be preserved and reused on the next invocation.
+    */
+    Tcl_Obj **aArg;
+    int nArg;
+    if( Tcl_ListObjGetElements(p->interp, p->pScript, &nArg, &aArg) ){
+      sqlite3_result_error(context, Tcl_GetStringResult(p->interp), -1); 
+      return;
+    }     
+    pCmd = Tcl_NewListObj(nArg, aArg);
+    Tcl_IncrRefCount(pCmd);
+    for(i=0; i<argc; i++){
+      sqlite3_value *pIn = argv[i];
+      Tcl_Obj *pVal;
+            
+      /* Set pVal to contain the i'th column of this row. */
+      switch( sqlite3_value_type(pIn) ){
+        case SQLITE_BLOB: {
+          int bytes = sqlite3_value_bytes(pIn);
+          pVal = Tcl_NewByteArrayObj(sqlite3_value_blob(pIn), bytes);
+          break;
+        }
+        case SQLITE_INTEGER: {
+          sqlite_int64 v = sqlite3_value_int64(pIn);
+          if( v>=-2147483647 && v<=2147483647 ){
+            pVal = Tcl_NewIntObj(v);
+          }else{
+            pVal = Tcl_NewWideIntObj(v);
+          }
+          break;
+        }
+        case SQLITE_FLOAT: {
+          double r = sqlite3_value_double(pIn);
+          pVal = Tcl_NewDoubleObj(r);
+          break;
+        }
+        case SQLITE_NULL: {
+          pVal = Tcl_NewStringObj("", 0);
+          break;
+        }
+        default: {
+          int bytes = sqlite3_value_bytes(pIn);
+          pVal = Tcl_NewStringObj((char *)sqlite3_value_text(pIn), bytes);
+          break;
+        }
+      }
+      rc = Tcl_ListObjAppendElement(p->interp, pCmd, pVal);
+      if( rc ){
+        Tcl_DecrRefCount(pCmd);
+        sqlite3_result_error(context, Tcl_GetStringResult(p->interp), -1); 
+        return;
+      }
+    }
+    if( !p->useEvalObjv ){
+      /* Tcl_EvalObjEx() will automatically call Tcl_EvalObjv() if pCmd
+      ** is a list without a string representation.  To prevent this from
+      ** happening, make sure pCmd has a valid string representation */
+      Tcl_GetString(pCmd);
+    }
+    rc = Tcl_EvalObjEx(p->interp, pCmd, TCL_EVAL_DIRECT);
+    Tcl_DecrRefCount(pCmd);
+  }
+
+  if( rc && rc!=TCL_RETURN ){
+    sqlite3_result_error(context, Tcl_GetStringResult(p->interp), -1); 
+  }else{
+    Tcl_Obj *pVar = Tcl_GetObjResult(p->interp);
+    int n;
+    u8 *data;
+    char *zType = pVar->typePtr ? pVar->typePtr->name : "";
+    char c = zType[0];
+    if( c=='b' && strcmp(zType,"bytearray")==0 && pVar->bytes==0 ){
+      /* Only return a BLOB type if the Tcl variable is a bytearray and
+      ** has no string representation. */
+      data = Tcl_GetByteArrayFromObj(pVar, &n);
+      sqlite3_result_blob(context, data, n, SQLITE_TRANSIENT);
+    }else if( c=='b' && strcmp(zType,"boolean")==0 ){
+      Tcl_GetIntFromObj(0, pVar, &n);
+      sqlite3_result_int(context, n);
+    }else if( c=='d' && strcmp(zType,"double")==0 ){
+      double r;
+      Tcl_GetDoubleFromObj(0, pVar, &r);
+      sqlite3_result_double(context, r);
+    }else if( (c=='w' && strcmp(zType,"wideInt")==0) ||
+          (c=='i' && strcmp(zType,"int")==0) ){
+      Tcl_WideInt v;
+      Tcl_GetWideIntFromObj(0, pVar, &v);
+      sqlite3_result_int64(context, v);
+    }else{
+      data = (unsigned char *)Tcl_GetStringFromObj(pVar, &n);
+      sqlite3_result_text(context, (char *)data, n, SQLITE_TRANSIENT);
+    }
+  }
+}
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+/*
+** This is the authentication function.  It appends the authentication
+** type code and the two arguments to zCmd[] then invokes the result
+** on the interpreter.  The reply is examined to determine if the
+** authentication fails or succeeds.
+*/
+static int auth_callback(
+  void *pArg,
+  int code,
+  const char *zArg1,
+  const char *zArg2,
+  const char *zArg3,
+  const char *zArg4
+){
+  char *zCode;
+  Tcl_DString str;
+  int rc;
+  const char *zReply;
+  SqliteDb *pDb = (SqliteDb*)pArg;
+
+  switch( code ){
+    case SQLITE_COPY              : zCode="SQLITE_COPY"; break;
+    case SQLITE_CREATE_INDEX      : zCode="SQLITE_CREATE_INDEX"; break;
+    case SQLITE_CREATE_TABLE      : zCode="SQLITE_CREATE_TABLE"; break;
+    case SQLITE_CREATE_TEMP_INDEX : zCode="SQLITE_CREATE_TEMP_INDEX"; break;
+    case SQLITE_CREATE_TEMP_TABLE : zCode="SQLITE_CREATE_TEMP_TABLE"; break;
+    case SQLITE_CREATE_TEMP_TRIGGER: zCode="SQLITE_CREATE_TEMP_TRIGGER"; break;
+    case SQLITE_CREATE_TEMP_VIEW  : zCode="SQLITE_CREATE_TEMP_VIEW"; break;
+    case SQLITE_CREATE_TRIGGER    : zCode="SQLITE_CREATE_TRIGGER"; break;
+    case SQLITE_CREATE_VIEW       : zCode="SQLITE_CREATE_VIEW"; break;
+    case SQLITE_DELETE            : zCode="SQLITE_DELETE"; break;
+    case SQLITE_DROP_INDEX        : zCode="SQLITE_DROP_INDEX"; break;
+    case SQLITE_DROP_TABLE        : zCode="SQLITE_DROP_TABLE"; break;
+    case SQLITE_DROP_TEMP_INDEX   : zCode="SQLITE_DROP_TEMP_INDEX"; break;
+    case SQLITE_DROP_TEMP_TABLE   : zCode="SQLITE_DROP_TEMP_TABLE"; break;
+    case SQLITE_DROP_TEMP_TRIGGER : zCode="SQLITE_DROP_TEMP_TRIGGER"; break;
+    case SQLITE_DROP_TEMP_VIEW    : zCode="SQLITE_DROP_TEMP_VIEW"; break;
+    case SQLITE_DROP_TRIGGER      : zCode="SQLITE_DROP_TRIGGER"; break;
+    case SQLITE_DROP_VIEW         : zCode="SQLITE_DROP_VIEW"; break;
+    case SQLITE_INSERT            : zCode="SQLITE_INSERT"; break;
+    case SQLITE_PRAGMA            : zCode="SQLITE_PRAGMA"; break;
+    case SQLITE_READ              : zCode="SQLITE_READ"; break;
+    case SQLITE_SELECT            : zCode="SQLITE_SELECT"; break;
+    case SQLITE_TRANSACTION       : zCode="SQLITE_TRANSACTION"; break;
+    case SQLITE_UPDATE            : zCode="SQLITE_UPDATE"; break;
+    case SQLITE_ATTACH            : zCode="SQLITE_ATTACH"; break;
+    case SQLITE_DETACH            : zCode="SQLITE_DETACH"; break;
+    case SQLITE_ALTER_TABLE       : zCode="SQLITE_ALTER_TABLE"; break;
+    case SQLITE_REINDEX           : zCode="SQLITE_REINDEX"; break;
+    case SQLITE_ANALYZE           : zCode="SQLITE_ANALYZE"; break;
+    case SQLITE_CREATE_VTABLE     : zCode="SQLITE_CREATE_VTABLE"; break;
+    case SQLITE_DROP_VTABLE       : zCode="SQLITE_DROP_VTABLE"; break;
+    case SQLITE_FUNCTION          : zCode="SQLITE_FUNCTION"; break;
+    default                       : zCode="????"; break;
+  }
+  Tcl_DStringInit(&str);
+  Tcl_DStringAppend(&str, pDb->zAuth, -1);
+  Tcl_DStringAppendElement(&str, zCode);
+  Tcl_DStringAppendElement(&str, zArg1 ? zArg1 : "");
+  Tcl_DStringAppendElement(&str, zArg2 ? zArg2 : "");
+  Tcl_DStringAppendElement(&str, zArg3 ? zArg3 : "");
+  Tcl_DStringAppendElement(&str, zArg4 ? zArg4 : "");
+  rc = Tcl_GlobalEval(pDb->interp, Tcl_DStringValue(&str));
+  Tcl_DStringFree(&str);
+  zReply = Tcl_GetStringResult(pDb->interp);
+  if( strcmp(zReply,"SQLITE_OK")==0 ){
+    rc = SQLITE_OK;
+  }else if( strcmp(zReply,"SQLITE_DENY")==0 ){
+    rc = SQLITE_DENY;
+  }else if( strcmp(zReply,"SQLITE_IGNORE")==0 ){
+    rc = SQLITE_IGNORE;
+  }else{
+    rc = 999;
+  }
+  return rc;
+}
+#endif /* SQLITE_OMIT_AUTHORIZATION */
+
+/*
+** zText is a pointer to text obtained via an sqlite3_result_text()
+** or similar interface. This routine returns a Tcl string object, 
+** reference count set to 0, containing the text. If a translation
+** between iso8859 and UTF-8 is required, it is preformed.
+*/
+static Tcl_Obj *dbTextToObj(char const *zText){
+  Tcl_Obj *pVal;
+#ifdef UTF_TRANSLATION_NEEDED
+  Tcl_DString dCol;
+  Tcl_DStringInit(&dCol);
+  Tcl_ExternalToUtfDString(NULL, zText, -1, &dCol);
+  pVal = Tcl_NewStringObj(Tcl_DStringValue(&dCol), -1);
+  Tcl_DStringFree(&dCol);
+#else
+  pVal = Tcl_NewStringObj(zText, -1);
+#endif
+  return pVal;
+}
+
+/*
+** This routine reads a line of text from FILE in, stores
+** the text in memory obtained from malloc() and returns a pointer
+** to the text.  NULL is returned at end of file, or if malloc()
+** fails.
+**
+** The interface is like "readline" but no command-line editing
+** is done.
+**
+** copied from shell.c from '.import' command
+*/
+static char *local_getline(char *zPrompt, FILE *in){
+  char *zLine;
+  int nLine;
+  int n;
+  int eol;
+
+  nLine = 100;
+  zLine = malloc( nLine );
+  if( zLine==0 ) return 0;
+  n = 0;
+  eol = 0;
+  while( !eol ){
+    if( n+100>nLine ){
+      nLine = nLine*2 + 100;
+      zLine = realloc(zLine, nLine);
+      if( zLine==0 ) return 0;
+    }
+    if( fgets(&zLine[n], nLine - n, in)==0 ){
+      if( n==0 ){
+        free(zLine);
+        return 0;
+      }
+      zLine[n] = 0;
+      eol = 1;
+      break;
+    }
+    while( zLine[n] ){ n++; }
+    if( n>0 && zLine[n-1]=='\n' ){
+      n--;
+      zLine[n] = 0;
+      eol = 1;
+    }
+  }
+  zLine = realloc( zLine, n+1 );
+  return zLine;
+}
+
+
+/*
+** Figure out the column names for the data returned by the statement
+** passed as the second argument.
+**
+** If parameter papColName is not NULL, then *papColName is set to point
+** at an array allocated using Tcl_Alloc(). It is the callers responsibility
+** to free this array using Tcl_Free(), and to decrement the reference
+** count of each Tcl_Obj* member of the array.
+**
+** The return value of this function is the number of columns of data
+** returned by pStmt (and hence the size of the *papColName array).
+**
+** If pArray is not NULL, then it contains the name of a Tcl array
+** variable. The "*" member of this array is set to a list containing
+** the names of the columns returned by the statement, in order from
+** left to right. e.g. if the names of the returned columns are a, b and
+** c, it does the equivalent of the tcl command:
+**
+**     set ${pArray}(*) {a b c}
+*/
+static int
+computeColumnNames(
+  Tcl_Interp *interp, 
+  sqlite3_stmt *pStmt,              /* SQL statement */
+  Tcl_Obj ***papColName,            /* OUT: Array of column names */
+  Tcl_Obj *pArray                   /* Name of array variable (may be null) */
+){
+  int nCol;
+
+  /* Compute column names */
+  nCol = sqlite3_column_count(pStmt);
+  if( papColName ){
+    int i;
+    Tcl_Obj **apColName = (Tcl_Obj**)Tcl_Alloc( sizeof(Tcl_Obj*)*nCol );
+    for(i=0; i<nCol; i++){
+      apColName[i] = dbTextToObj(sqlite3_column_name(pStmt,i));
+      Tcl_IncrRefCount(apColName[i]);
+    }
+
+    /* If results are being stored in an array variable, then create
+    ** the array(*) entry for that array
+    */
+    if( pArray ){
+      Tcl_Obj *pColList = Tcl_NewObj();
+      Tcl_Obj *pStar = Tcl_NewStringObj("*", -1);
+      Tcl_IncrRefCount(pColList);
+      for(i=0; i<nCol; i++){
+        Tcl_ListObjAppendElement(interp, pColList, apColName[i]);
+      }
+      Tcl_IncrRefCount(pStar);
+      Tcl_ObjSetVar2(interp, pArray, pStar, pColList,0);
+      Tcl_DecrRefCount(pColList);
+      Tcl_DecrRefCount(pStar);
+    }
+    *papColName = apColName;
+  }
+
+  return nCol;
+}
+
+/*
+** The "sqlite" command below creates a new Tcl command for each
+** connection it opens to an SQLite database.  This routine is invoked
+** whenever one of those connection-specific commands is executed
+** in Tcl.  For example, if you run Tcl code like this:
+**
+**       sqlite3 db1  "my_database"
+**       db1 close
+**
+** The first command opens a connection to the "my_database" database
+** and calls that connection "db1".  The second command causes this
+** subroutine to be invoked.
+*/
+static int DbObjCmd(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
+  SqliteDb *pDb = (SqliteDb*)cd;
+  int choice;
+  int rc = TCL_OK;
+  static const char *DB_strs[] = {
+    "authorizer",         "busy",              "cache",
+    "changes",            "close",             "collate",
+    "collation_needed",   "commit_hook",       "complete",
+    "copy",               "enable_load_extension","errorcode",
+    "eval",               "exists",            "function",
+    "incrblob",           "interrupt",         "last_insert_rowid",
+    "nullvalue",          "onecolumn",         "profile",
+    "progress",           "rekey",             "rollback_hook",
+    "timeout",            "total_changes",     "trace",
+    "transaction",        "update_hook",       "version",
+    0                    
+  };
+  enum DB_enum {
+    DB_AUTHORIZER,        DB_BUSY,             DB_CACHE,
+    DB_CHANGES,           DB_CLOSE,            DB_COLLATE,
+    DB_COLLATION_NEEDED,  DB_COMMIT_HOOK,      DB_COMPLETE,
+    DB_COPY,              DB_ENABLE_LOAD_EXTENSION,DB_ERRORCODE,
+    DB_EVAL,              DB_EXISTS,           DB_FUNCTION,
+    DB_INCRBLOB,          DB_INTERRUPT,        DB_LAST_INSERT_ROWID,
+    DB_NULLVALUE,         DB_ONECOLUMN,        DB_PROFILE,
+    DB_PROGRESS,          DB_REKEY,            DB_ROLLBACK_HOOK,
+    DB_TIMEOUT,           DB_TOTAL_CHANGES,    DB_TRACE,
+    DB_TRANSACTION,       DB_UPDATE_HOOK,      DB_VERSION
+  };
+  /* don't leave trailing commas on DB_enum, it confuses the AIX xlc compiler */
+
+  if( objc<2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIndexFromObj(interp, objv[1], DB_strs, "option", 0, &choice) ){
+    return TCL_ERROR;
+  }
+
+  switch( (enum DB_enum)choice ){
+
+  /*    $db authorizer ?CALLBACK?
+  **
+  ** Invoke the given callback to authorize each SQL operation as it is
+  ** compiled.  5 arguments are appended to the callback before it is
+  ** invoked:
+  **
+  **   (1) The authorization type (ex: SQLITE_CREATE_TABLE, SQLITE_INSERT, ...)
+  **   (2) First descriptive name (depends on authorization type)
+  **   (3) Second descriptive name
+  **   (4) Name of the database (ex: "main", "temp")
+  **   (5) Name of trigger that is doing the access
+  **
+  ** The callback should return on of the following strings: SQLITE_OK,
+  ** SQLITE_IGNORE, or SQLITE_DENY.  Any other return value is an error.
+  **
+  ** If this method is invoked with no arguments, the current authorization
+  ** callback string is returned.
+  */
+  case DB_AUTHORIZER: {
+#ifdef SQLITE_OMIT_AUTHORIZATION
+    Tcl_AppendResult(interp, "authorization not available in this build", 0);
+    return TCL_ERROR;
+#else
+    if( objc>3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "?CALLBACK?");
+      return TCL_ERROR;
+    }else if( objc==2 ){
+      if( pDb->zAuth ){
+        Tcl_AppendResult(interp, pDb->zAuth, 0);
+      }
+    }else{
+      char *zAuth;
+      int len;
+      if( pDb->zAuth ){
+        Tcl_Free(pDb->zAuth);
+      }
+      zAuth = Tcl_GetStringFromObj(objv[2], &len);
+      if( zAuth && len>0 ){
+        pDb->zAuth = Tcl_Alloc( len + 1 );
+        memcpy(pDb->zAuth, zAuth, len+1);
+      }else{
+        pDb->zAuth = 0;
+      }
+      if( pDb->zAuth ){
+        pDb->interp = interp;
+        sqlite3_set_authorizer(pDb->db, auth_callback, pDb);
+      }else{
+        sqlite3_set_authorizer(pDb->db, 0, 0);
+      }
+    }
+#endif
+    break;
+  }
+
+  /*    $db busy ?CALLBACK?
+  **
+  ** Invoke the given callback if an SQL statement attempts to open
+  ** a locked database file.
+  */
+  case DB_BUSY: {
+    if( objc>3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "CALLBACK");
+      return TCL_ERROR;
+    }else if( objc==2 ){
+      if( pDb->zBusy ){
+        Tcl_AppendResult(interp, pDb->zBusy, 0);
+      }
+    }else{
+      char *zBusy;
+      int len;
+      if( pDb->zBusy ){
+        Tcl_Free(pDb->zBusy);
+      }
+      zBusy = Tcl_GetStringFromObj(objv[2], &len);
+      if( zBusy && len>0 ){
+        pDb->zBusy = Tcl_Alloc( len + 1 );
+        memcpy(pDb->zBusy, zBusy, len+1);
+      }else{
+        pDb->zBusy = 0;
+      }
+      if( pDb->zBusy ){
+        pDb->interp = interp;
+        sqlite3_busy_handler(pDb->db, DbBusyHandler, pDb);
+      }else{
+        sqlite3_busy_handler(pDb->db, 0, 0);
+      }
+    }
+    break;
+  }
+
+  /*     $db cache flush
+  **     $db cache size n
+  **
+  ** Flush the prepared statement cache, or set the maximum number of
+  ** cached statements.
+  */
+  case DB_CACHE: {
+    char *subCmd;
+    int n;
+
+    if( objc<=2 ){
+      Tcl_WrongNumArgs(interp, 1, objv, "cache option ?arg?");
+      return TCL_ERROR;
+    }
+    subCmd = Tcl_GetStringFromObj( objv[2], 0 );
+    if( *subCmd=='f' && strcmp(subCmd,"flush")==0 ){
+      if( objc!=3 ){
+        Tcl_WrongNumArgs(interp, 2, objv, "flush");
+        return TCL_ERROR;
+      }else{
+        flushStmtCache( pDb );
+      }
+    }else if( *subCmd=='s' && strcmp(subCmd,"size")==0 ){
+      if( objc!=4 ){
+        Tcl_WrongNumArgs(interp, 2, objv, "size n");
+        return TCL_ERROR;
+      }else{
+        if( TCL_ERROR==Tcl_GetIntFromObj(interp, objv[3], &n) ){
+          Tcl_AppendResult( interp, "cannot convert \"", 
+               Tcl_GetStringFromObj(objv[3],0), "\" to integer", 0);
+          return TCL_ERROR;
+        }else{
+          if( n<0 ){
+            flushStmtCache( pDb );
+            n = 0;
+          }else if( n>MAX_PREPARED_STMTS ){
+            n = MAX_PREPARED_STMTS;
+          }
+          pDb->maxStmt = n;
+        }
+      }
+    }else{
+      Tcl_AppendResult( interp, "bad option \"", 
+          Tcl_GetStringFromObj(objv[2],0), "\": must be flush or size", 0);
+      return TCL_ERROR;
+    }
+    break;
+  }
+
+  /*     $db changes
+  **
+  ** Return the number of rows that were modified, inserted, or deleted by
+  ** the most recent INSERT, UPDATE or DELETE statement, not including 
+  ** any changes made by trigger programs.
+  */
+  case DB_CHANGES: {
+    Tcl_Obj *pResult;
+    if( objc!=2 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "");
+      return TCL_ERROR;
+    }
+    pResult = Tcl_GetObjResult(interp);
+    Tcl_SetIntObj(pResult, sqlite3_changes(pDb->db));
+    break;
+  }
+
+  /*    $db close
+  **
+  ** Shutdown the database
+  */
+  case DB_CLOSE: {
+    Tcl_DeleteCommand(interp, Tcl_GetStringFromObj(objv[0], 0));
+    break;
+  }
+
+  /*
+  **     $db collate NAME SCRIPT
+  **
+  ** Create a new SQL collation function called NAME.  Whenever
+  ** that function is called, invoke SCRIPT to evaluate the function.
+  */
+  case DB_COLLATE: {
+    SqlCollate *pCollate;
+    char *zName;
+    char *zScript;
+    int nScript;
+    if( objc!=4 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "NAME SCRIPT");
+      return TCL_ERROR;
+    }
+    zName = Tcl_GetStringFromObj(objv[2], 0);
+    zScript = Tcl_GetStringFromObj(objv[3], &nScript);
+    pCollate = (SqlCollate*)Tcl_Alloc( sizeof(*pCollate) + nScript + 1 );
+    if( pCollate==0 ) return TCL_ERROR;
+    pCollate->interp = interp;
+    pCollate->pNext = pDb->pCollate;
+    pCollate->zScript = (char*)&pCollate[1];
+    pDb->pCollate = pCollate;
+    memcpy(pCollate->zScript, zScript, nScript+1);
+    if( sqlite3_create_collation(pDb->db, zName, SQLITE_UTF8, 
+        pCollate, tclSqlCollate) ){
+      Tcl_SetResult(interp, (char *)sqlite3_errmsg(pDb->db), TCL_VOLATILE);
+      return TCL_ERROR;
+    }
+    break;
+  }
+
+  /*
+  **     $db collation_needed SCRIPT
+  **
+  ** Create a new SQL collation function called NAME.  Whenever
+  ** that function is called, invoke SCRIPT to evaluate the function.
+  */
+  case DB_COLLATION_NEEDED: {
+    if( objc!=3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "SCRIPT");
+      return TCL_ERROR;
+    }
+    if( pDb->pCollateNeeded ){
+      Tcl_DecrRefCount(pDb->pCollateNeeded);
+    }
+    pDb->pCollateNeeded = Tcl_DuplicateObj(objv[2]);
+    Tcl_IncrRefCount(pDb->pCollateNeeded);
+    sqlite3_collation_needed(pDb->db, pDb, tclCollateNeeded);
+    break;
+  }
+
+  /*    $db commit_hook ?CALLBACK?
+  **
+  ** Invoke the given callback just before committing every SQL transaction.
+  ** If the callback throws an exception or returns non-zero, then the
+  ** transaction is aborted.  If CALLBACK is an empty string, the callback
+  ** is disabled.
+  */
+  case DB_COMMIT_HOOK: {
+    if( objc>3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "?CALLBACK?");
+      return TCL_ERROR;
+    }else if( objc==2 ){
+      if( pDb->zCommit ){
+        Tcl_AppendResult(interp, pDb->zCommit, 0);
+      }
+    }else{
+      char *zCommit;
+      int len;
+      if( pDb->zCommit ){
+        Tcl_Free(pDb->zCommit);
+      }
+      zCommit = Tcl_GetStringFromObj(objv[2], &len);
+      if( zCommit && len>0 ){
+        pDb->zCommit = Tcl_Alloc( len + 1 );
+        memcpy(pDb->zCommit, zCommit, len+1);
+      }else{
+        pDb->zCommit = 0;
+      }
+      if( pDb->zCommit ){
+        pDb->interp = interp;
+        sqlite3_commit_hook(pDb->db, DbCommitHandler, pDb);
+      }else{
+        sqlite3_commit_hook(pDb->db, 0, 0);
+      }
+    }
+    break;
+  }
+
+  /*    $db complete SQL
+  **
+  ** Return TRUE if SQL is a complete SQL statement.  Return FALSE if
+  ** additional lines of input are needed.  This is similar to the
+  ** built-in "info complete" command of Tcl.
+  */
+  case DB_COMPLETE: {
+#ifndef SQLITE_OMIT_COMPLETE
+    Tcl_Obj *pResult;
+    int isComplete;
+    if( objc!=3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "SQL");
+      return TCL_ERROR;
+    }
+    isComplete = sqlite3_complete( Tcl_GetStringFromObj(objv[2], 0) );
+    pResult = Tcl_GetObjResult(interp);
+    Tcl_SetBooleanObj(pResult, isComplete);
+#endif
+    break;
+  }
+
+  /*    $db copy conflict-algorithm table filename ?SEPARATOR? ?NULLINDICATOR?
+  **
+  ** Copy data into table from filename, optionally using SEPARATOR
+  ** as column separators.  If a column contains a null string, or the
+  ** value of NULLINDICATOR, a NULL is inserted for the column.
+  ** conflict-algorithm is one of the sqlite conflict algorithms:
+  **    rollback, abort, fail, ignore, replace
+  ** On success, return the number of lines processed, not necessarily same
+  ** as 'db changes' due to conflict-algorithm selected.
+  **
+  ** This code is basically an implementation/enhancement of
+  ** the sqlite3 shell.c ".import" command.
+  **
+  ** This command usage is equivalent to the sqlite2.x COPY statement,
+  ** which imports file data into a table using the PostgreSQL COPY file format:
+  **   $db copy $conflit_algo $table_name $filename \t \\N
+  */
+  case DB_COPY: {
+    char *zTable;               /* Insert data into this table */
+    char *zFile;                /* The file from which to extract data */
+    char *zConflict;            /* The conflict algorithm to use */
+    sqlite3_stmt *pStmt;        /* A statement */
+    int nCol;                   /* Number of columns in the table */
+    int nByte;                  /* Number of bytes in an SQL string */
+    int i, j;                   /* Loop counters */
+    int nSep;                   /* Number of bytes in zSep[] */
+    int nNull;                  /* Number of bytes in zNull[] */
+    char *zSql;                 /* An SQL statement */
+    char *zLine;                /* A single line of input from the file */
+    char **azCol;               /* zLine[] broken up into columns */
+    char *zCommit;              /* How to commit changes */
+    FILE *in;                   /* The input file */
+    int lineno = 0;             /* Line number of input file */
+    char zLineNum[80];          /* Line number print buffer */
+    Tcl_Obj *pResult;           /* interp result */
+
+    char *zSep;
+    char *zNull;
+    if( objc<5 || objc>7 ){
+      Tcl_WrongNumArgs(interp, 2, objv, 
+         "CONFLICT-ALGORITHM TABLE FILENAME ?SEPARATOR? ?NULLINDICATOR?");
+      return TCL_ERROR;
+    }
+    if( objc>=6 ){
+      zSep = Tcl_GetStringFromObj(objv[5], 0);
+    }else{
+      zSep = "\t";
+    }
+    if( objc>=7 ){
+      zNull = Tcl_GetStringFromObj(objv[6], 0);
+    }else{
+      zNull = "";
+    }
+    zConflict = Tcl_GetStringFromObj(objv[2], 0);
+    zTable = Tcl_GetStringFromObj(objv[3], 0);
+    zFile = Tcl_GetStringFromObj(objv[4], 0);
+    nSep = strlen(zSep);
+    nNull = strlen(zNull);
+    if( nSep==0 ){
+      Tcl_AppendResult(interp,"Error: non-null separator required for copy",0);
+      return TCL_ERROR;
+    }
+    if(strcasecmp(zConflict, "rollback") != 0 &&
+       strcasecmp(zConflict, "abort"   ) != 0 &&
+       strcasecmp(zConflict, "fail"    ) != 0 &&
+       strcasecmp(zConflict, "ignore"  ) != 0 &&
+       strcasecmp(zConflict, "replace" ) != 0 ) {
+      Tcl_AppendResult(interp, "Error: \"", zConflict, 
+            "\", conflict-algorithm must be one of: rollback, "
+            "abort, fail, ignore, or replace", 0);
+      return TCL_ERROR;
+    }
+    zSql = sqlite3_mprintf("SELECT * FROM '%q'", zTable);
+    if( zSql==0 ){
+      Tcl_AppendResult(interp, "Error: no such table: ", zTable, 0);
+      return TCL_ERROR;
+    }
+    nByte = strlen(zSql);
+    rc = sqlite3_prepare(pDb->db, zSql, -1, &pStmt, 0);
+    sqlite3_free(zSql);
+    if( rc ){
+      Tcl_AppendResult(interp, "Error: ", sqlite3_errmsg(pDb->db), 0);
+      nCol = 0;
+    }else{
+      nCol = sqlite3_column_count(pStmt);
+    }
+    sqlite3_finalize(pStmt);
+    if( nCol==0 ) {
+      return TCL_ERROR;
+    }
+    zSql = malloc( nByte + 50 + nCol*2 );
+    if( zSql==0 ) {
+      Tcl_AppendResult(interp, "Error: can't malloc()", 0);
+      return TCL_ERROR;
+    }
+    sqlite3_snprintf(nByte+50, zSql, "INSERT OR %q INTO '%q' VALUES(?",
+         zConflict, zTable);
+    j = strlen(zSql);
+    for(i=1; i<nCol; i++){
+      zSql[j++] = ',';
+      zSql[j++] = '?';
+    }
+    zSql[j++] = ')';
+    zSql[j] = 0;
+    rc = sqlite3_prepare(pDb->db, zSql, -1, &pStmt, 0);
+    free(zSql);
+    if( rc ){
+      Tcl_AppendResult(interp, "Error: ", sqlite3_errmsg(pDb->db), 0);
+      sqlite3_finalize(pStmt);
+      return TCL_ERROR;
+    }
+    in = fopen(zFile, "rb");
+    if( in==0 ){
+      Tcl_AppendResult(interp, "Error: cannot open file: ", zFile, NULL);
+      sqlite3_finalize(pStmt);
+      return TCL_ERROR;
+    }
+    azCol = malloc( sizeof(azCol[0])*(nCol+1) );
+    if( azCol==0 ) {
+      Tcl_AppendResult(interp, "Error: can't malloc()", 0);
+      fclose(in);
+      return TCL_ERROR;
+    }
+    (void)sqlite3_exec(pDb->db, "BEGIN", 0, 0, 0);
+    zCommit = "COMMIT";
+    while( (zLine = local_getline(0, in))!=0 ){
+      char *z;
+      i = 0;
+      lineno++;
+      azCol[0] = zLine;
+      for(i=0, z=zLine; *z; z++){
+        if( *z==zSep[0] && strncmp(z, zSep, nSep)==0 ){
+          *z = 0;
+          i++;
+          if( i<nCol ){
+            azCol[i] = &z[nSep];
+            z += nSep-1;
+          }
+        }
+      }
+      if( i+1!=nCol ){
+        char *zErr;
+        int nErr = strlen(zFile) + 200;
+        zErr = malloc(nErr);
+        if( zErr ){
+          sqlite3_snprintf(nErr, zErr,
+             "Error: %s line %d: expected %d columns of data but found %d",
+             zFile, lineno, nCol, i+1);
+          Tcl_AppendResult(interp, zErr, 0);
+          free(zErr);
+        }
+        zCommit = "ROLLBACK";
+        break;
+      }
+      for(i=0; i<nCol; i++){
+        /* check for null data, if so, bind as null */
+        if ((nNull>0 && strcmp(azCol[i], zNull)==0) || strlen(azCol[i])==0) {
+          sqlite3_bind_null(pStmt, i+1);
+        }else{
+          sqlite3_bind_text(pStmt, i+1, azCol[i], -1, SQLITE_STATIC);
+        }
+      }
+      sqlite3_step(pStmt);
+      rc = sqlite3_reset(pStmt);
+      free(zLine);
+      if( rc!=SQLITE_OK ){
+        Tcl_AppendResult(interp,"Error: ", sqlite3_errmsg(pDb->db), 0);
+        zCommit = "ROLLBACK";
+        break;
+      }
+    }
+    free(azCol);
+    fclose(in);
+    sqlite3_finalize(pStmt);
+    (void)sqlite3_exec(pDb->db, zCommit, 0, 0, 0);
+
+    if( zCommit[0] == 'C' ){
+      /* success, set result as number of lines processed */
+      pResult = Tcl_GetObjResult(interp);
+      Tcl_SetIntObj(pResult, lineno);
+      rc = TCL_OK;
+    }else{
+      /* failure, append lineno where failed */
+      sqlite3_snprintf(sizeof(zLineNum), zLineNum,"%d",lineno);
+      Tcl_AppendResult(interp,", failed while processing line: ",zLineNum,0);
+      rc = TCL_ERROR;
+    }
+    break;
+  }
+
+  /*
+  **    $db enable_load_extension BOOLEAN
+  **
+  ** Turn the extension loading feature on or off.  It if off by
+  ** default.
+  */
+  case DB_ENABLE_LOAD_EXTENSION: {
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+    int onoff;
+    if( objc!=3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "BOOLEAN");
+      return TCL_ERROR;
+    }
+    if( Tcl_GetBooleanFromObj(interp, objv[2], &onoff) ){
+      return TCL_ERROR;
+    }
+    sqlite3_enable_load_extension(pDb->db, onoff);
+    break;
+#else
+    Tcl_AppendResult(interp, "extension loading is turned off at compile-time",
+                     0);
+    return TCL_ERROR;
+#endif
+  }
+
+  /*
+  **    $db errorcode
+  **
+  ** Return the numeric error code that was returned by the most recent
+  ** call to sqlite3_exec().
+  */
+  case DB_ERRORCODE: {
+    Tcl_SetObjResult(interp, Tcl_NewIntObj(sqlite3_errcode(pDb->db)));
+    break;
+  }
+   
+  /*
+  **    $db eval $sql ?array? ?{  ...code... }?
+  **    $db onecolumn $sql
+  **
+  ** The SQL statement in $sql is evaluated.  For each row, the values are
+  ** placed in elements of the array named "array" and ...code... is executed.
+  ** If "array" and "code" are omitted, then no callback is every invoked.
+  ** If "array" is an empty string, then the values are placed in variables
+  ** that have the same name as the fields extracted by the query.
+  **
+  ** The onecolumn method is the equivalent of:
+  **     lindex [$db eval $sql] 0
+  */
+  case DB_ONECOLUMN:
+  case DB_EVAL:
+  case DB_EXISTS: {
+    char const *zSql;      /* Next SQL statement to execute */
+    char const *zLeft;     /* What is left after first stmt in zSql */
+    sqlite3_stmt *pStmt;   /* Compiled SQL statment */
+    Tcl_Obj *pArray;       /* Name of array into which results are written */
+    Tcl_Obj *pScript;      /* Script to run for each result set */
+    Tcl_Obj **apParm;      /* Parameters that need a Tcl_DecrRefCount() */
+    int nParm;             /* Number of entries used in apParm[] */
+    Tcl_Obj *aParm[10];    /* Static space for apParm[] in the common case */
+    Tcl_Obj *pRet;         /* Value to be returned */
+    SqlPreparedStmt *pPreStmt;  /* Pointer to a prepared statement */
+    int rc2;
+
+    if( choice==DB_EVAL ){
+      if( objc<3 || objc>5 ){
+        Tcl_WrongNumArgs(interp, 2, objv, "SQL ?ARRAY-NAME? ?SCRIPT?");
+        return TCL_ERROR;
+      }
+      pRet = Tcl_NewObj();
+      Tcl_IncrRefCount(pRet);
+    }else{
+      if( objc!=3 ){
+        Tcl_WrongNumArgs(interp, 2, objv, "SQL");
+        return TCL_ERROR;
+      }
+      if( choice==DB_EXISTS ){
+        pRet = Tcl_NewBooleanObj(0);
+        Tcl_IncrRefCount(pRet);
+      }else{
+        pRet = 0;
+      }
+    }
+    if( objc==3 ){
+      pArray = pScript = 0;
+    }else if( objc==4 ){
+      pArray = 0;
+      pScript = objv[3];
+    }else{
+      pArray = objv[3];
+      if( Tcl_GetString(pArray)[0]==0 ) pArray = 0;
+      pScript = objv[4];
+    }
+
+    Tcl_IncrRefCount(objv[2]);
+    zSql = Tcl_GetStringFromObj(objv[2], 0);
+    while( rc==TCL_OK && zSql[0] ){
+      int i;                     /* Loop counter */
+      int nVar;                  /* Number of bind parameters in the pStmt */
+      int nCol = -1;             /* Number of columns in the result set */
+      Tcl_Obj **apColName = 0;   /* Array of column names */
+      int len;                   /* String length of zSql */
+  
+      /* Try to find a SQL statement that has already been compiled and
+      ** which matches the next sequence of SQL.
+      */
+      pStmt = 0;
+      len = strlen(zSql);
+      for(pPreStmt = pDb->stmtList; pPreStmt; pPreStmt=pPreStmt->pNext){
+        int n = pPreStmt->nSql;
+        if( len>=n 
+            && memcmp(pPreStmt->zSql, zSql, n)==0
+            && (zSql[n]==0 || zSql[n-1]==';')
+        ){
+          pStmt = pPreStmt->pStmt;
+          zLeft = &zSql[pPreStmt->nSql];
+
+          /* When a prepared statement is found, unlink it from the
+          ** cache list.  It will later be added back to the beginning
+          ** of the cache list in order to implement LRU replacement.
+          */
+          if( pPreStmt->pPrev ){
+            pPreStmt->pPrev->pNext = pPreStmt->pNext;
+          }else{
+            pDb->stmtList = pPreStmt->pNext;
+          }
+          if( pPreStmt->pNext ){
+            pPreStmt->pNext->pPrev = pPreStmt->pPrev;
+          }else{
+            pDb->stmtLast = pPreStmt->pPrev;
+          }
+          pDb->nStmt--;
+          break;
+        }
+      }
+  
+      /* If no prepared statement was found.  Compile the SQL text
+      */
+      if( pStmt==0 ){
+        if( SQLITE_OK!=sqlite3_prepare_v2(pDb->db, zSql, -1, &pStmt, &zLeft) ){
+          Tcl_SetObjResult(interp, dbTextToObj(sqlite3_errmsg(pDb->db)));
+          rc = TCL_ERROR;
+          break;
+        }
+        if( pStmt==0 ){
+          if( SQLITE_OK!=sqlite3_errcode(pDb->db) ){
+            /* A compile-time error in the statement
+            */
+            Tcl_SetObjResult(interp, dbTextToObj(sqlite3_errmsg(pDb->db)));
+            rc = TCL_ERROR;
+            break;
+          }else{
+            /* The statement was a no-op.  Continue to the next statement
+            ** in the SQL string.
+            */
+            zSql = zLeft;
+            continue;
+          }
+        }
+        assert( pPreStmt==0 );
+      }
+
+      /* Bind values to parameters that begin with $ or :
+      */  
+      nVar = sqlite3_bind_parameter_count(pStmt);
+      nParm = 0;
+      if( nVar>sizeof(aParm)/sizeof(aParm[0]) ){
+        apParm = (Tcl_Obj**)Tcl_Alloc(nVar*sizeof(apParm[0]));
+      }else{
+        apParm = aParm;
+      }
+      for(i=1; i<=nVar; i++){
+        const char *zVar = sqlite3_bind_parameter_name(pStmt, i);
+        if( zVar!=0 && (zVar[0]=='$' || zVar[0]==':' || zVar[0]=='@') ){
+          Tcl_Obj *pVar = Tcl_GetVar2Ex(interp, &zVar[1], 0, 0);
+          if( pVar ){
+            int n;
+            u8 *data;
+            char *zType = pVar->typePtr ? pVar->typePtr->name : "";
+            char c = zType[0];
+            if( zVar[0]=='@' ||
+               (c=='b' && strcmp(zType,"bytearray")==0 && pVar->bytes==0) ){
+              /* Load a BLOB type if the Tcl variable is a bytearray and
+              ** it has no string representation or the host
+              ** parameter name begins with "@". */
+              data = Tcl_GetByteArrayFromObj(pVar, &n);
+              sqlite3_bind_blob(pStmt, i, data, n, SQLITE_STATIC);
+              Tcl_IncrRefCount(pVar);
+              apParm[nParm++] = pVar;
+            }else if( c=='b' && strcmp(zType,"boolean")==0 ){
+              Tcl_GetIntFromObj(interp, pVar, &n);
+              sqlite3_bind_int(pStmt, i, n);
+            }else if( c=='d' && strcmp(zType,"double")==0 ){
+              double r;
+              Tcl_GetDoubleFromObj(interp, pVar, &r);
+              sqlite3_bind_double(pStmt, i, r);
+            }else if( (c=='w' && strcmp(zType,"wideInt")==0) ||
+                  (c=='i' && strcmp(zType,"int")==0) ){
+              Tcl_WideInt v;
+              Tcl_GetWideIntFromObj(interp, pVar, &v);
+              sqlite3_bind_int64(pStmt, i, v);
+            }else{
+              data = (unsigned char *)Tcl_GetStringFromObj(pVar, &n);
+              sqlite3_bind_text(pStmt, i, (char *)data, n, SQLITE_STATIC);
+              Tcl_IncrRefCount(pVar);
+              apParm[nParm++] = pVar;
+            }
+          }else{
+            sqlite3_bind_null( pStmt, i );
+          }
+        }
+      }
+
+      /* Execute the SQL
+      */
+      while( rc==TCL_OK && pStmt && SQLITE_ROW==sqlite3_step(pStmt) ){
+
+	/* Compute column names. This must be done after the first successful
+	** call to sqlite3_step(), in case the query is recompiled and the
+        ** number or names of the returned columns changes. 
+        */
+        assert(!pArray||pScript);
+        if (nCol < 0) {
+          Tcl_Obj ***ap = (pScript?&apColName:0);
+          nCol = computeColumnNames(interp, pStmt, ap, pArray);
+        }
+
+        for(i=0; i<nCol; i++){
+          Tcl_Obj *pVal;
+          
+          /* Set pVal to contain the i'th column of this row. */
+          switch( sqlite3_column_type(pStmt, i) ){
+            case SQLITE_BLOB: {
+              int bytes = sqlite3_column_bytes(pStmt, i);
+              const char *zBlob = sqlite3_column_blob(pStmt, i);
+              if( !zBlob ) bytes = 0;
+              pVal = Tcl_NewByteArrayObj((u8*)zBlob, bytes);
+              break;
+            }
+            case SQLITE_INTEGER: {
+              sqlite_int64 v = sqlite3_column_int64(pStmt, i);
+              if( v>=-2147483647 && v<=2147483647 ){
+                pVal = Tcl_NewIntObj(v);
+              }else{
+                pVal = Tcl_NewWideIntObj(v);
+              }
+              break;
+            }
+            case SQLITE_FLOAT: {
+              double r = sqlite3_column_double(pStmt, i);
+              pVal = Tcl_NewDoubleObj(r);
+              break;
+            }
+            case SQLITE_NULL: {
+              pVal = dbTextToObj(pDb->zNull);
+              break;
+            }
+            default: {
+              pVal = dbTextToObj((char *)sqlite3_column_text(pStmt, i));
+              break;
+            }
+          }
+  
+          if( pScript ){
+            if( pArray==0 ){
+              Tcl_ObjSetVar2(interp, apColName[i], 0, pVal, 0);
+            }else{
+              Tcl_ObjSetVar2(interp, pArray, apColName[i], pVal, 0);
+            }
+          }else if( choice==DB_ONECOLUMN ){
+            assert( pRet==0 );
+            if( pRet==0 ){
+              pRet = pVal;
+              Tcl_IncrRefCount(pRet);
+            }
+            rc = TCL_BREAK;
+            i = nCol;
+          }else if( choice==DB_EXISTS ){
+            Tcl_DecrRefCount(pRet);
+            pRet = Tcl_NewBooleanObj(1);
+            Tcl_IncrRefCount(pRet);
+            rc = TCL_BREAK;
+            i = nCol;
+          }else{
+            Tcl_ListObjAppendElement(interp, pRet, pVal);
+          }
+        }
+  
+        if( pScript ){
+          rc = Tcl_EvalObjEx(interp, pScript, 0);
+          if( rc==TCL_CONTINUE ){
+            rc = TCL_OK;
+          }
+        }
+      }
+      if( rc==TCL_BREAK ){
+        rc = TCL_OK;
+      }
+
+      /* Free the column name objects */
+      if( pScript ){
+        /* If the query returned no rows, but an array variable was 
+        ** specified, call computeColumnNames() now to populate the 
+        ** arrayname(*) variable.
+        */
+        if (pArray && nCol < 0) {
+          Tcl_Obj ***ap = (pScript?&apColName:0);
+          nCol = computeColumnNames(interp, pStmt, ap, pArray);
+        }
+        for(i=0; i<nCol; i++){
+          Tcl_DecrRefCount(apColName[i]);
+        }
+        Tcl_Free((char*)apColName);
+      }
+
+      /* Free the bound string and blob parameters */
+      for(i=0; i<nParm; i++){
+        Tcl_DecrRefCount(apParm[i]);
+      }
+      if( apParm!=aParm ){
+        Tcl_Free((char*)apParm);
+      }
+
+      /* Reset the statement.  If the result code is SQLITE_SCHEMA, then
+      ** flush the statement cache and try the statement again.
+      */
+      rc2 = sqlite3_reset(pStmt);
+      if( SQLITE_OK!=rc2 ){
+        /* If a run-time error occurs, report the error and stop reading
+        ** the SQL
+        */
+        Tcl_SetObjResult(interp, dbTextToObj(sqlite3_errmsg(pDb->db)));
+        sqlite3_finalize(pStmt);
+        rc = TCL_ERROR;
+        if( pPreStmt ) Tcl_Free((char*)pPreStmt);
+        break;
+      }else if( pDb->maxStmt<=0 ){
+        /* If the cache is turned off, deallocated the statement */
+        if( pPreStmt ) Tcl_Free((char*)pPreStmt);
+        sqlite3_finalize(pStmt);
+      }else{
+        /* Everything worked and the cache is operational.
+        ** Create a new SqlPreparedStmt structure if we need one.
+        ** (If we already have one we can just reuse it.)
+        */
+        if( pPreStmt==0 ){
+          len = zLeft - zSql;
+          pPreStmt = (SqlPreparedStmt*)Tcl_Alloc( sizeof(*pPreStmt) );
+          if( pPreStmt==0 ) return TCL_ERROR;
+          pPreStmt->pStmt = pStmt;
+          pPreStmt->nSql = len;
+          pPreStmt->zSql = sqlite3_sql(pStmt);
+          assert( strlen(pPreStmt->zSql)==len );
+          assert( 0==memcmp(pPreStmt->zSql, zSql, len) );
+        }
+
+        /* Add the prepared statement to the beginning of the cache list
+        */
+        pPreStmt->pNext = pDb->stmtList;
+        pPreStmt->pPrev = 0;
+        if( pDb->stmtList ){
+         pDb->stmtList->pPrev = pPreStmt;
+        }
+        pDb->stmtList = pPreStmt;
+        if( pDb->stmtLast==0 ){
+          assert( pDb->nStmt==0 );
+          pDb->stmtLast = pPreStmt;
+        }else{
+          assert( pDb->nStmt>0 );
+        }
+        pDb->nStmt++;
+   
+        /* If we have too many statement in cache, remove the surplus from the
+        ** end of the cache list.
+        */
+        while( pDb->nStmt>pDb->maxStmt ){
+          sqlite3_finalize(pDb->stmtLast->pStmt);
+          pDb->stmtLast = pDb->stmtLast->pPrev;
+          Tcl_Free((char*)pDb->stmtLast->pNext);
+          pDb->stmtLast->pNext = 0;
+          pDb->nStmt--;
+        }
+      }
+
+      /* Proceed to the next statement */
+      zSql = zLeft;
+    }
+    Tcl_DecrRefCount(objv[2]);
+
+    if( pRet ){
+      if( rc==TCL_OK ){
+        Tcl_SetObjResult(interp, pRet);
+      }
+      Tcl_DecrRefCount(pRet);
+    }else if( rc==TCL_OK ){
+      Tcl_ResetResult(interp);
+    }
+    break;
+  }
+
+  /*
+  **     $db function NAME SCRIPT
+  **
+  ** Create a new SQL function called NAME.  Whenever that function is
+  ** called, invoke SCRIPT to evaluate the function.
+  */
+  case DB_FUNCTION: {
+    SqlFunc *pFunc;
+    Tcl_Obj *pScript;
+    char *zName;
+    if( objc!=4 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "NAME SCRIPT");
+      return TCL_ERROR;
+    }
+    zName = Tcl_GetStringFromObj(objv[2], 0);
+    pScript = objv[3];
+    pFunc = findSqlFunc(pDb, zName);
+    if( pFunc==0 ) return TCL_ERROR;
+    if( pFunc->pScript ){
+      Tcl_DecrRefCount(pFunc->pScript);
+    }
+    pFunc->pScript = pScript;
+    Tcl_IncrRefCount(pScript);
+    pFunc->useEvalObjv = safeToUseEvalObjv(interp, pScript);
+    rc = sqlite3_create_function(pDb->db, zName, -1, SQLITE_UTF8,
+        pFunc, tclSqlFunc, 0, 0);
+    if( rc!=SQLITE_OK ){
+      rc = TCL_ERROR;
+      Tcl_SetResult(interp, (char *)sqlite3_errmsg(pDb->db), TCL_VOLATILE);
+    }
+    break;
+  }
+
+  /*
+  **     $db incrblob ?-readonly? ?DB? TABLE COLUMN ROWID
+  */
+  case DB_INCRBLOB: {
+#ifdef SQLITE_OMIT_INCRBLOB
+    Tcl_AppendResult(interp, "incrblob not available in this build", 0);
+    return TCL_ERROR;
+#else
+    int isReadonly = 0;
+    const char *zDb = "main";
+    const char *zTable;
+    const char *zColumn;
+    sqlite_int64 iRow;
+
+    /* Check for the -readonly option */
+    if( objc>3 && strcmp(Tcl_GetString(objv[2]), "-readonly")==0 ){
+      isReadonly = 1;
+    }
+
+    if( objc!=(5+isReadonly) && objc!=(6+isReadonly) ){
+      Tcl_WrongNumArgs(interp, 2, objv, "?-readonly? ?DB? TABLE COLUMN ROWID");
+      return TCL_ERROR;
+    }
+
+    if( objc==(6+isReadonly) ){
+      zDb = Tcl_GetString(objv[2]);
+    }
+    zTable = Tcl_GetString(objv[objc-3]);
+    zColumn = Tcl_GetString(objv[objc-2]);
+    rc = Tcl_GetWideIntFromObj(interp, objv[objc-1], &iRow);
+
+    if( rc==TCL_OK ){
+      rc = createIncrblobChannel(
+          interp, pDb, zDb, zTable, zColumn, iRow, isReadonly
+      );
+    }
+#endif
+    break;
+  }
+
+  /*
+  **     $db interrupt
+  **
+  ** Interrupt the execution of the inner-most SQL interpreter.  This
+  ** causes the SQL statement to return an error of SQLITE_INTERRUPT.
+  */
+  case DB_INTERRUPT: {
+    sqlite3_interrupt(pDb->db);
+    break;
+  }
+
+  /*
+  **     $db nullvalue ?STRING?
+  **
+  ** Change text used when a NULL comes back from the database. If ?STRING?
+  ** is not present, then the current string used for NULL is returned.
+  ** If STRING is present, then STRING is returned.
+  **
+  */
+  case DB_NULLVALUE: {
+    if( objc!=2 && objc!=3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "NULLVALUE");
+      return TCL_ERROR;
+    }
+    if( objc==3 ){
+      int len;
+      char *zNull = Tcl_GetStringFromObj(objv[2], &len);
+      if( pDb->zNull ){
+        Tcl_Free(pDb->zNull);
+      }
+      if( zNull && len>0 ){
+        pDb->zNull = Tcl_Alloc( len + 1 );
+        strncpy(pDb->zNull, zNull, len);
+        pDb->zNull[len] = '\0';
+      }else{
+        pDb->zNull = 0;
+      }
+    }
+    Tcl_SetObjResult(interp, dbTextToObj(pDb->zNull));
+    break;
+  }
+
+  /*
+  **     $db last_insert_rowid 
+  **
+  ** Return an integer which is the ROWID for the most recent insert.
+  */
+  case DB_LAST_INSERT_ROWID: {
+    Tcl_Obj *pResult;
+    Tcl_WideInt rowid;
+    if( objc!=2 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "");
+      return TCL_ERROR;
+    }
+    rowid = sqlite3_last_insert_rowid(pDb->db);
+    pResult = Tcl_GetObjResult(interp);
+    Tcl_SetWideIntObj(pResult, rowid);
+    break;
+  }
+
+  /*
+  ** The DB_ONECOLUMN method is implemented together with DB_EVAL.
+  */
+
+  /*    $db progress ?N CALLBACK?
+  ** 
+  ** Invoke the given callback every N virtual machine opcodes while executing
+  ** queries.
+  */
+  case DB_PROGRESS: {
+    if( objc==2 ){
+      if( pDb->zProgress ){
+        Tcl_AppendResult(interp, pDb->zProgress, 0);
+      }
+    }else if( objc==4 ){
+      char *zProgress;
+      int len;
+      int N;
+      if( TCL_OK!=Tcl_GetIntFromObj(interp, objv[2], &N) ){
+        return TCL_ERROR;
+      };
+      if( pDb->zProgress ){
+        Tcl_Free(pDb->zProgress);
+      }
+      zProgress = Tcl_GetStringFromObj(objv[3], &len);
+      if( zProgress && len>0 ){
+        pDb->zProgress = Tcl_Alloc( len + 1 );
+        memcpy(pDb->zProgress, zProgress, len+1);
+      }else{
+        pDb->zProgress = 0;
+      }
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+      if( pDb->zProgress ){
+        pDb->interp = interp;
+        sqlite3_progress_handler(pDb->db, N, DbProgressHandler, pDb);
+      }else{
+        sqlite3_progress_handler(pDb->db, 0, 0, 0);
+      }
+#endif
+    }else{
+      Tcl_WrongNumArgs(interp, 2, objv, "N CALLBACK");
+      return TCL_ERROR;
+    }
+    break;
+  }
+
+  /*    $db profile ?CALLBACK?
+  **
+  ** Make arrangements to invoke the CALLBACK routine after each SQL statement
+  ** that has run.  The text of the SQL and the amount of elapse time are
+  ** appended to CALLBACK before the script is run.
+  */
+  case DB_PROFILE: {
+    if( objc>3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "?CALLBACK?");
+      return TCL_ERROR;
+    }else if( objc==2 ){
+      if( pDb->zProfile ){
+        Tcl_AppendResult(interp, pDb->zProfile, 0);
+      }
+    }else{
+      char *zProfile;
+      int len;
+      if( pDb->zProfile ){
+        Tcl_Free(pDb->zProfile);
+      }
+      zProfile = Tcl_GetStringFromObj(objv[2], &len);
+      if( zProfile && len>0 ){
+        pDb->zProfile = Tcl_Alloc( len + 1 );
+        memcpy(pDb->zProfile, zProfile, len+1);
+      }else{
+        pDb->zProfile = 0;
+      }
+#ifndef SQLITE_OMIT_TRACE
+      if( pDb->zProfile ){
+        pDb->interp = interp;
+        sqlite3_profile(pDb->db, DbProfileHandler, pDb);
+      }else{
+        sqlite3_profile(pDb->db, 0, 0);
+      }
+#endif
+    }
+    break;
+  }
+
+  /*
+  **     $db rekey KEY
+  **
+  ** Change the encryption key on the currently open database.
+  */
+  case DB_REKEY: {
+    int nKey;
+    void *pKey;
+    if( objc!=3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "KEY");
+      return TCL_ERROR;
+    }
+    pKey = Tcl_GetByteArrayFromObj(objv[2], &nKey);
+#ifdef SQLITE_HAS_CODEC
+    rc = sqlite3_rekey(pDb->db, pKey, nKey);
+    if( rc ){
+      Tcl_AppendResult(interp, sqlite3ErrStr(rc), 0);
+      rc = TCL_ERROR;
+    }
+#endif
+    break;
+  }
+
+  /*
+  **     $db timeout MILLESECONDS
+  **
+  ** Delay for the number of milliseconds specified when a file is locked.
+  */
+  case DB_TIMEOUT: {
+    int ms;
+    if( objc!=3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "MILLISECONDS");
+      return TCL_ERROR;
+    }
+    if( Tcl_GetIntFromObj(interp, objv[2], &ms) ) return TCL_ERROR;
+    sqlite3_busy_timeout(pDb->db, ms);
+    break;
+  }
+  
+  /*
+  **     $db total_changes
+  **
+  ** Return the number of rows that were modified, inserted, or deleted 
+  ** since the database handle was created.
+  */
+  case DB_TOTAL_CHANGES: {
+    Tcl_Obj *pResult;
+    if( objc!=2 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "");
+      return TCL_ERROR;
+    }
+    pResult = Tcl_GetObjResult(interp);
+    Tcl_SetIntObj(pResult, sqlite3_total_changes(pDb->db));
+    break;
+  }
+
+  /*    $db trace ?CALLBACK?
+  **
+  ** Make arrangements to invoke the CALLBACK routine for each SQL statement
+  ** that is executed.  The text of the SQL is appended to CALLBACK before
+  ** it is executed.
+  */
+  case DB_TRACE: {
+    if( objc>3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "?CALLBACK?");
+      return TCL_ERROR;
+    }else if( objc==2 ){
+      if( pDb->zTrace ){
+        Tcl_AppendResult(interp, pDb->zTrace, 0);
+      }
+    }else{
+      char *zTrace;
+      int len;
+      if( pDb->zTrace ){
+        Tcl_Free(pDb->zTrace);
+      }
+      zTrace = Tcl_GetStringFromObj(objv[2], &len);
+      if( zTrace && len>0 ){
+        pDb->zTrace = Tcl_Alloc( len + 1 );
+        memcpy(pDb->zTrace, zTrace, len+1);
+      }else{
+        pDb->zTrace = 0;
+      }
+#ifndef SQLITE_OMIT_TRACE
+      if( pDb->zTrace ){
+        pDb->interp = interp;
+        sqlite3_trace(pDb->db, DbTraceHandler, pDb);
+      }else{
+        sqlite3_trace(pDb->db, 0, 0);
+      }
+#endif
+    }
+    break;
+  }
+
+  /*    $db transaction [-deferred|-immediate|-exclusive] SCRIPT
+  **
+  ** Start a new transaction (if we are not already in the midst of a
+  ** transaction) and execute the TCL script SCRIPT.  After SCRIPT
+  ** completes, either commit the transaction or roll it back if SCRIPT
+  ** throws an exception.  Or if no new transation was started, do nothing.
+  ** pass the exception on up the stack.
+  **
+  ** This command was inspired by Dave Thomas's talk on Ruby at the
+  ** 2005 O'Reilly Open Source Convention (OSCON).
+  */
+  case DB_TRANSACTION: {
+    int inTrans;
+    Tcl_Obj *pScript;
+    const char *zBegin = "BEGIN";
+    if( objc!=3 && objc!=4 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "[TYPE] SCRIPT");
+      return TCL_ERROR;
+    }
+    if( objc==3 ){
+      pScript = objv[2];
+    } else {
+      static const char *TTYPE_strs[] = {
+        "deferred",   "exclusive",  "immediate", 0
+      };
+      enum TTYPE_enum {
+        TTYPE_DEFERRED, TTYPE_EXCLUSIVE, TTYPE_IMMEDIATE
+      };
+      int ttype;
+      if( Tcl_GetIndexFromObj(interp, objv[2], TTYPE_strs, "transaction type",
+                              0, &ttype) ){
+        return TCL_ERROR;
+      }
+      switch( (enum TTYPE_enum)ttype ){
+        case TTYPE_DEFERRED:    /* no-op */;                 break;
+        case TTYPE_EXCLUSIVE:   zBegin = "BEGIN EXCLUSIVE";  break;
+        case TTYPE_IMMEDIATE:   zBegin = "BEGIN IMMEDIATE";  break;
+      }
+      pScript = objv[3];
+    }
+    inTrans = !sqlite3_get_autocommit(pDb->db);
+    if( !inTrans ){
+      (void)sqlite3_exec(pDb->db, zBegin, 0, 0, 0);
+    }
+    rc = Tcl_EvalObjEx(interp, pScript, 0);
+    if( !inTrans ){
+      const char *zEnd;
+      if( rc==TCL_ERROR ){
+        zEnd = "ROLLBACK";
+      } else {
+        zEnd = "COMMIT";
+      }
+      if( sqlite3_exec(pDb->db, zEnd, 0, 0, 0) ){
+        sqlite3_exec(pDb->db, "ROLLBACK", 0, 0, 0);
+      }
+    }
+    break;
+  }
+
+  /*
+  **    $db update_hook ?script?
+  **    $db rollback_hook ?script?
+  */
+  case DB_UPDATE_HOOK: 
+  case DB_ROLLBACK_HOOK: {
+
+    /* set ppHook to point at pUpdateHook or pRollbackHook, depending on 
+    ** whether [$db update_hook] or [$db rollback_hook] was invoked.
+    */
+    Tcl_Obj **ppHook; 
+    if( choice==DB_UPDATE_HOOK ){
+      ppHook = &pDb->pUpdateHook;
+    }else{
+      ppHook = &pDb->pRollbackHook;
+    }
+
+    if( objc!=2 && objc!=3 ){
+       Tcl_WrongNumArgs(interp, 2, objv, "?SCRIPT?");
+       return TCL_ERROR;
+    }
+    if( *ppHook ){
+      Tcl_SetObjResult(interp, *ppHook);
+      if( objc==3 ){
+        Tcl_DecrRefCount(*ppHook);
+        *ppHook = 0;
+      }
+    }
+    if( objc==3 ){
+      assert( !(*ppHook) );
+      if( Tcl_GetCharLength(objv[2])>0 ){
+        *ppHook = objv[2];
+        Tcl_IncrRefCount(*ppHook);
+      }
+    }
+
+    sqlite3_update_hook(pDb->db, (pDb->pUpdateHook?DbUpdateHandler:0), pDb);
+    sqlite3_rollback_hook(pDb->db,(pDb->pRollbackHook?DbRollbackHandler:0),pDb);
+
+    break;
+  }
+
+  /*    $db version
+  **
+  ** Return the version string for this database.
+  */
+  case DB_VERSION: {
+    Tcl_SetResult(interp, (char *)sqlite3_libversion(), TCL_STATIC);
+    break;
+  }
+
+
+  } /* End of the SWITCH statement */
+  return rc;
+}
+
+/*
+**   sqlite3 DBNAME FILENAME ?-vfs VFSNAME? ?-key KEY? ?-readonly BOOLEAN?
+**                           ?-create BOOLEAN? ?-nomutex BOOLEAN?
+**
+** This is the main Tcl command.  When the "sqlite" Tcl command is
+** invoked, this routine runs to process that command.
+**
+** The first argument, DBNAME, is an arbitrary name for a new
+** database connection.  This command creates a new command named
+** DBNAME that is used to control that connection.  The database
+** connection is deleted when the DBNAME command is deleted.
+**
+** The second argument is the name of the database file.
+**
+*/
+static int DbMain(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
+  SqliteDb *p;
+  void *pKey = 0;
+  int nKey = 0;
+  const char *zArg;
+  char *zErrMsg;
+  int i;
+  const char *zFile;
+  const char *zVfs = 0;
+  int flags = SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
+  Tcl_DString translatedFilename;
+  if( objc==2 ){
+    zArg = Tcl_GetStringFromObj(objv[1], 0);
+    if( strcmp(zArg,"-version")==0 ){
+      Tcl_AppendResult(interp,sqlite3_version,0);
+      return TCL_OK;
+    }
+    if( strcmp(zArg,"-has-codec")==0 ){
+#ifdef SQLITE_HAS_CODEC
+      Tcl_AppendResult(interp,"1",0);
+#else
+      Tcl_AppendResult(interp,"0",0);
+#endif
+      return TCL_OK;
+    }
+  }
+  for(i=3; i+1<objc; i+=2){
+    zArg = Tcl_GetString(objv[i]);
+    if( strcmp(zArg,"-key")==0 ){
+      pKey = Tcl_GetByteArrayFromObj(objv[i+1], &nKey);
+    }else if( strcmp(zArg, "-vfs")==0 ){
+      i++;
+      zVfs = Tcl_GetString(objv[i]);
+    }else if( strcmp(zArg, "-readonly")==0 ){
+      int b;
+      if( Tcl_GetBooleanFromObj(interp, objv[i+1], &b) ) return TCL_ERROR;
+      if( b ){
+        flags &= ~(SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
+        flags |= SQLITE_OPEN_READONLY;
+      }else{
+        flags &= ~SQLITE_OPEN_READONLY;
+        flags |= SQLITE_OPEN_READWRITE;
+      }
+    }else if( strcmp(zArg, "-create")==0 ){
+      int b;
+      if( Tcl_GetBooleanFromObj(interp, objv[i+1], &b) ) return TCL_ERROR;
+      if( b && (flags & SQLITE_OPEN_READONLY)==0 ){
+        flags |= SQLITE_OPEN_CREATE;
+      }else{
+        flags &= ~SQLITE_OPEN_CREATE;
+      }
+    }else if( strcmp(zArg, "-nomutex")==0 ){
+      int b;
+      if( Tcl_GetBooleanFromObj(interp, objv[i+1], &b) ) return TCL_ERROR;
+      if( b ){
+        flags |= SQLITE_OPEN_NOMUTEX;
+      }else{
+        flags &= ~SQLITE_OPEN_NOMUTEX;
+      }
+    }else{
+      Tcl_AppendResult(interp, "unknown option: ", zArg, (char*)0);
+      return TCL_ERROR;
+    }
+  }
+  if( objc<3 || (objc&1)!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, 
+      "HANDLE FILENAME ?-vfs VFSNAME? ?-readonly BOOLEAN? ?-create BOOLEAN?"
+      " ?-nomutex BOOLEAN?"
+#ifdef SQLITE_HAS_CODEC
+      " ?-key CODECKEY?"
+#endif
+    );
+    return TCL_ERROR;
+  }
+  zErrMsg = 0;
+  p = (SqliteDb*)Tcl_Alloc( sizeof(*p) );
+  if( p==0 ){
+    Tcl_SetResult(interp, "malloc failed", TCL_STATIC);
+    return TCL_ERROR;
+  }
+  memset(p, 0, sizeof(*p));
+  zFile = Tcl_GetStringFromObj(objv[2], 0);
+  zFile = Tcl_TranslateFileName(interp, zFile, &translatedFilename);
+  sqlite3_open_v2(zFile, &p->db, flags, zVfs);
+  Tcl_DStringFree(&translatedFilename);
+  if( SQLITE_OK!=sqlite3_errcode(p->db) ){
+    zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(p->db));
+    sqlite3_close(p->db);
+    p->db = 0;
+  }
+#ifdef SQLITE_HAS_CODEC
+  if( p->db ){
+    sqlite3_key(p->db, pKey, nKey);
+  }
+#endif
+  if( p->db==0 ){
+    Tcl_SetResult(interp, zErrMsg, TCL_VOLATILE);
+    Tcl_Free((char*)p);
+    sqlite3_free(zErrMsg);
+    return TCL_ERROR;
+  }
+  p->maxStmt = NUM_PREPARED_STMTS;
+  p->interp = interp;
+  zArg = Tcl_GetStringFromObj(objv[1], 0);
+  Tcl_CreateObjCommand(interp, zArg, DbObjCmd, (char*)p, DbDeleteCmd);
+  return TCL_OK;
+}
+
+/*
+** Provide a dummy Tcl_InitStubs if we are using this as a static
+** library.
+*/
+#ifndef USE_TCL_STUBS
+# undef  Tcl_InitStubs
+# define Tcl_InitStubs(a,b,c)
+#endif
+
+/*
+** Make sure we have a PACKAGE_VERSION macro defined.  This will be
+** defined automatically by the TEA makefile.  But other makefiles
+** do not define it.
+*/
+#ifndef PACKAGE_VERSION
+# define PACKAGE_VERSION SQLITE_VERSION
+#endif
+
+/*
+** Initialize this module.
+**
+** This Tcl module contains only a single new Tcl command named "sqlite".
+** (Hence there is no namespace.  There is no point in using a namespace
+** if the extension only supplies one new name!)  The "sqlite" command is
+** used to open a new SQLite database.  See the DbMain() routine above
+** for additional information.
+*/
+EXTERN int Sqlite3_Init(Tcl_Interp *interp){
+  Tcl_InitStubs(interp, "8.4", 0);
+  Tcl_CreateObjCommand(interp, "sqlite3", (Tcl_ObjCmdProc*)DbMain, 0, 0);
+  Tcl_PkgProvide(interp, "sqlite3", PACKAGE_VERSION);
+  Tcl_CreateObjCommand(interp, "sqlite", (Tcl_ObjCmdProc*)DbMain, 0, 0);
+  Tcl_PkgProvide(interp, "sqlite", PACKAGE_VERSION);
+  return TCL_OK;
+}
+EXTERN int Tclsqlite3_Init(Tcl_Interp *interp){ return Sqlite3_Init(interp); }
+EXTERN int Sqlite3_SafeInit(Tcl_Interp *interp){ return TCL_OK; }
+EXTERN int Tclsqlite3_SafeInit(Tcl_Interp *interp){ return TCL_OK; }
+
+#ifndef SQLITE_3_SUFFIX_ONLY
+EXTERN int Sqlite_Init(Tcl_Interp *interp){ return Sqlite3_Init(interp); }
+EXTERN int Tclsqlite_Init(Tcl_Interp *interp){ return Sqlite3_Init(interp); }
+EXTERN int Sqlite_SafeInit(Tcl_Interp *interp){ return TCL_OK; }
+EXTERN int Tclsqlite_SafeInit(Tcl_Interp *interp){ return TCL_OK; }
+#endif
+
+#ifdef TCLSH
+/*****************************************************************************
+** The code that follows is used to build standalone TCL interpreters
+** that are statically linked with SQLite.  
+*/
+
+/*
+** If the macro TCLSH is one, then put in code this for the
+** "main" routine that will initialize Tcl and take input from
+** standard input, or if a file is named on the command line
+** the TCL interpreter reads and evaluates that file.
+*/
+#if TCLSH==1
+static char zMainloop[] =
+  "set line {}\n"
+  "while {![eof stdin]} {\n"
+    "if {$line!=\"\"} {\n"
+      "puts -nonewline \"> \"\n"
+    "} else {\n"
+      "puts -nonewline \"% \"\n"
+    "}\n"
+    "flush stdout\n"
+    "append line [gets stdin]\n"
+    "if {[info complete $line]} {\n"
+      "if {[catch {uplevel #0 $line} result]} {\n"
+        "puts stderr \"Error: $result\"\n"
+      "} elseif {$result!=\"\"} {\n"
+        "puts $result\n"
+      "}\n"
+      "set line {}\n"
+    "} else {\n"
+      "append line \\n\n"
+    "}\n"
+  "}\n"
+;
+#endif
+
+/*
+** If the macro TCLSH is two, then get the main loop code out of
+** the separate file "spaceanal_tcl.h".
+*/
+#if TCLSH==2
+static char zMainloop[] = 
+#include "spaceanal_tcl.h"
+;
+#endif
+
+#define TCLSH_MAIN main   /* Needed to fake out mktclapp */
+int TCLSH_MAIN(int argc, char **argv){
+  Tcl_Interp *interp;
+  Tcl_FindExecutable(argv[0]);
+  interp = Tcl_CreateInterp();
+  Sqlite3_Init(interp);
+#ifdef SQLITE_TEST
+  {
+    extern int Md5_Init(Tcl_Interp*);
+    extern int Sqliteconfig_Init(Tcl_Interp*);
+    extern int Sqlitetest1_Init(Tcl_Interp*);
+    extern int Sqlitetest2_Init(Tcl_Interp*);
+    extern int Sqlitetest3_Init(Tcl_Interp*);
+    extern int Sqlitetest4_Init(Tcl_Interp*);
+    extern int Sqlitetest5_Init(Tcl_Interp*);
+    extern int Sqlitetest6_Init(Tcl_Interp*);
+    extern int Sqlitetest7_Init(Tcl_Interp*);
+    extern int Sqlitetest8_Init(Tcl_Interp*);
+    extern int Sqlitetest9_Init(Tcl_Interp*);
+    extern int Sqlitetestasync_Init(Tcl_Interp*);
+    extern int Sqlitetest_autoext_Init(Tcl_Interp*);
+    extern int Sqlitetest_func_Init(Tcl_Interp*);
+    extern int Sqlitetest_hexio_Init(Tcl_Interp*);
+    extern int Sqlitetest_malloc_Init(Tcl_Interp*);
+    extern int Sqlitetest_mutex_Init(Tcl_Interp*);
+    extern int Sqlitetestschema_Init(Tcl_Interp*);
+    extern int Sqlitetestsse_Init(Tcl_Interp*);
+    extern int Sqlitetesttclvar_Init(Tcl_Interp*);
+    extern int SqlitetestThread_Init(Tcl_Interp*);
+    extern int SqlitetestOnefile_Init();
+    extern int SqlitetestOsinst_Init(Tcl_Interp*);
+
+    Md5_Init(interp);
+    Sqliteconfig_Init(interp);
+    Sqlitetest1_Init(interp);
+    Sqlitetest2_Init(interp);
+    Sqlitetest3_Init(interp);
+    Sqlitetest4_Init(interp);
+    Sqlitetest5_Init(interp);
+    Sqlitetest6_Init(interp);
+    Sqlitetest7_Init(interp);
+    Sqlitetest8_Init(interp);
+    Sqlitetest9_Init(interp);
+    Sqlitetestasync_Init(interp);
+    Sqlitetest_autoext_Init(interp);
+    Sqlitetest_func_Init(interp);
+    Sqlitetest_hexio_Init(interp);
+    Sqlitetest_malloc_Init(interp);
+    Sqlitetest_mutex_Init(interp);
+    Sqlitetestschema_Init(interp);
+    Sqlitetesttclvar_Init(interp);
+    SqlitetestThread_Init(interp);
+    SqlitetestOnefile_Init(interp);
+    SqlitetestOsinst_Init(interp);
+
+#ifdef SQLITE_SSE
+    Sqlitetestsse_Init(interp);
+#endif
+  }
+#endif
+  if( argc>=2 || TCLSH==2 ){
+    int i;
+    char zArgc[32];
+    sqlite3_snprintf(sizeof(zArgc), zArgc, "%d", argc-(3-TCLSH));
+    Tcl_SetVar(interp,"argc", zArgc, TCL_GLOBAL_ONLY);
+    Tcl_SetVar(interp,"argv0",argv[1],TCL_GLOBAL_ONLY);
+    Tcl_SetVar(interp,"argv", "", TCL_GLOBAL_ONLY);
+    for(i=3-TCLSH; i<argc; i++){
+      Tcl_SetVar(interp, "argv", argv[i],
+          TCL_GLOBAL_ONLY | TCL_LIST_ELEMENT | TCL_APPEND_VALUE);
+    }
+    if( TCLSH==1 && Tcl_EvalFile(interp, argv[1])!=TCL_OK ){
+      const char *zInfo = Tcl_GetVar(interp, "errorInfo", TCL_GLOBAL_ONLY);
+      if( zInfo==0 ) zInfo = interp->result;
+      fprintf(stderr,"%s: %s\n", *argv, zInfo);
+      return 1;
+    }
+  }
+  if( argc<=1 || TCLSH==2 ){
+    Tcl_GlobalEval(interp, zMainloop);
+  }
+  return 0;
+}
+#endif /* TCLSH */
diff --git a/third_party/sqlite/src/test1.c b/third_party/sqlite/src/test1.c
new file mode 100755
index 0000000..f83d38f
--- /dev/null
+++ b/third_party/sqlite/src/test1.c
@@ -0,0 +1,4784 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing all sorts of SQLite interfaces.  This code
+** is not included in the SQLite library.  It is used for automated
+** testing of the SQLite library.
+**
+** $Id: test1.c,v 1.317 2008/07/31 02:05:04 shane Exp $
+*/
+#include "sqliteInt.h"
+#include "tcl.h"
+#include <stdlib.h>
+#include <string.h>
+
+/*
+** This is a copy of the first part of the SqliteDb structure in 
+** tclsqlite.c.  We need it here so that the get_sqlite_pointer routine
+** can extract the sqlite3* pointer from an existing Tcl SQLite
+** connection.
+*/
+struct SqliteDb {
+  sqlite3 *db;
+};
+
+/*
+** Convert text generated by the "%p" conversion format back into
+** a pointer.
+*/
+static int testHexToInt(int h){
+  if( h>='0' && h<='9' ){
+    return h - '0';
+  }else if( h>='a' && h<='f' ){
+    return h - 'a' + 10;
+  }else{
+    assert( h>='A' && h<='F' );
+    return h - 'A' + 10;
+  }
+}
+void *sqlite3TestTextToPtr(const char *z){
+  void *p;
+  u64 v;
+  u32 v2;
+  if( z[0]=='0' && z[1]=='x' ){
+    z += 2;
+  }
+  v = 0;
+  while( *z ){
+    v = (v<<4) + testHexToInt(*z);
+    z++;
+  }
+  if( sizeof(p)==sizeof(v) ){
+    memcpy(&p, &v, sizeof(p));
+  }else{
+    assert( sizeof(p)==sizeof(v2) );
+    v2 = (u32)v;
+    memcpy(&p, &v2, sizeof(p));
+  }
+  return p;
+}
+
+
+/*
+** A TCL command that returns the address of the sqlite* pointer
+** for an sqlite connection instance.  Bad things happen if the
+** input is not an sqlite connection.
+*/
+static int get_sqlite_pointer(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  struct SqliteDb *p;
+  Tcl_CmdInfo cmdInfo;
+  char zBuf[100];
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SQLITE-CONNECTION");
+    return TCL_ERROR;
+  }
+  if( !Tcl_GetCommandInfo(interp, Tcl_GetString(objv[1]), &cmdInfo) ){
+    Tcl_AppendResult(interp, "command not found: ",
+           Tcl_GetString(objv[1]), (char*)0);
+    return TCL_ERROR;
+  }
+  p = (struct SqliteDb*)cmdInfo.objClientData;
+  sprintf(zBuf, "%p", p->db);
+  if( strncmp(zBuf,"0x",2) ){
+    sprintf(zBuf, "0x%p", p->db);
+  }
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Decode a pointer to an sqlite3 object.
+*/
+int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb){
+  struct SqliteDb *p;
+  Tcl_CmdInfo cmdInfo;
+  if( Tcl_GetCommandInfo(interp, zA, &cmdInfo) ){
+    p = (struct SqliteDb*)cmdInfo.objClientData;
+    *ppDb = p->db;
+  }else{
+    *ppDb = (sqlite3*)sqlite3TestTextToPtr(zA);
+  }
+  return TCL_OK;
+}
+
+
+const char *sqlite3TestErrorName(int rc){
+  const char *zName = 0;
+  switch( rc & 0xff ){
+    case SQLITE_OK:         zName = "SQLITE_OK";          break;
+    case SQLITE_ERROR:      zName = "SQLITE_ERROR";       break;
+    case SQLITE_PERM:       zName = "SQLITE_PERM";        break;
+    case SQLITE_ABORT:      zName = "SQLITE_ABORT";       break;
+    case SQLITE_BUSY:       zName = "SQLITE_BUSY";        break;
+    case SQLITE_LOCKED:     zName = "SQLITE_LOCKED";      break;
+    case SQLITE_NOMEM:      zName = "SQLITE_NOMEM";       break;
+    case SQLITE_READONLY:   zName = "SQLITE_READONLY";    break;
+    case SQLITE_INTERRUPT:  zName = "SQLITE_INTERRUPT";   break;
+    case SQLITE_IOERR:      zName = "SQLITE_IOERR";       break;
+    case SQLITE_CORRUPT:    zName = "SQLITE_CORRUPT";     break;
+    case SQLITE_FULL:       zName = "SQLITE_FULL";        break;
+    case SQLITE_CANTOPEN:   zName = "SQLITE_CANTOPEN";    break;
+    case SQLITE_PROTOCOL:   zName = "SQLITE_PROTOCOL";    break;
+    case SQLITE_EMPTY:      zName = "SQLITE_EMPTY";       break;
+    case SQLITE_SCHEMA:     zName = "SQLITE_SCHEMA";      break;
+    case SQLITE_CONSTRAINT: zName = "SQLITE_CONSTRAINT";  break;
+    case SQLITE_MISMATCH:   zName = "SQLITE_MISMATCH";    break;
+    case SQLITE_MISUSE:     zName = "SQLITE_MISUSE";      break;
+    case SQLITE_NOLFS:      zName = "SQLITE_NOLFS";       break;
+    case SQLITE_AUTH:       zName = "SQLITE_AUTH";        break;
+    case SQLITE_FORMAT:     zName = "SQLITE_FORMAT";      break;
+    case SQLITE_RANGE:      zName = "SQLITE_RANGE";       break;
+    case SQLITE_ROW:        zName = "SQLITE_ROW";         break;
+    case SQLITE_DONE:       zName = "SQLITE_DONE";        break;
+    case SQLITE_NOTADB:     zName = "SQLITE_NOTADB";      break;
+    case SQLITE_TOOBIG:     zName = "SQLITE_TOOBIG";      break;
+    default:                zName = "SQLITE_Unknown";     break;
+  }
+  return zName;
+}
+#define t1ErrorName sqlite3TestErrorName
+
+/*
+** Convert an sqlite3_stmt* into an sqlite3*.  This depends on the
+** fact that the sqlite3* is the first field in the Vdbe structure.
+*/
+#define StmtToDb(X)   sqlite3_db_handle(X)
+
+/*
+** Check a return value to make sure it agrees with the results
+** from sqlite3_errcode.
+*/
+int sqlite3TestErrCode(Tcl_Interp *interp, sqlite3 *db, int rc){
+  if( rc!=SQLITE_MISUSE && rc!=SQLITE_OK && sqlite3_errcode(db)!=rc ){
+    char zBuf[200];
+    int r2 = sqlite3_errcode(db);
+    sprintf(zBuf, "error code %s (%d) does not match sqlite3_errcode %s (%d)",
+       t1ErrorName(rc), rc, t1ErrorName(r2), r2);
+    Tcl_ResetResult(interp);
+    Tcl_AppendResult(interp, zBuf, 0);
+    return 1;
+  }
+  return 0;
+}
+
+/*
+** Decode a pointer to an sqlite3_stmt object.
+*/
+static int getStmtPointer(
+  Tcl_Interp *interp, 
+  const char *zArg,  
+  sqlite3_stmt **ppStmt
+){
+  *ppStmt = (sqlite3_stmt*)sqlite3TestTextToPtr(zArg);
+  return TCL_OK;
+}
+
+/*
+** Generate a text representation of a pointer that can be understood
+** by the getDbPointer and getVmPointer routines above.
+**
+** The problem is, on some machines (Solaris) if you do a printf with
+** "%p" you cannot turn around and do a scanf with the same "%p" and
+** get your pointer back.  You have to prepend a "0x" before it will
+** work.  Or at least that is what is reported to me (drh).  But this
+** behavior varies from machine to machine.  The solution used her is
+** to test the string right after it is generated to see if it can be
+** understood by scanf, and if not, try prepending an "0x" to see if
+** that helps.  If nothing works, a fatal error is generated.
+*/
+int sqlite3TestMakePointerStr(Tcl_Interp *interp, char *zPtr, void *p){
+  sqlite3_snprintf(100, zPtr, "%p", p);
+  return TCL_OK;
+}
+
+/*
+** The callback routine for sqlite3_exec_printf().
+*/
+static int exec_printf_cb(void *pArg, int argc, char **argv, char **name){
+  Tcl_DString *str = (Tcl_DString*)pArg;
+  int i;
+
+  if( Tcl_DStringLength(str)==0 ){
+    for(i=0; i<argc; i++){
+      Tcl_DStringAppendElement(str, name[i] ? name[i] : "NULL");
+    }
+  }
+  for(i=0; i<argc; i++){
+    Tcl_DStringAppendElement(str, argv[i] ? argv[i] : "NULL");
+  }
+  return 0;
+}
+
+/*
+** The I/O tracing callback.
+*/
+#if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
+static FILE *iotrace_file = 0;
+static void io_trace_callback(const char *zFormat, ...){
+  va_list ap;
+  va_start(ap, zFormat);
+  vfprintf(iotrace_file, zFormat, ap);
+  va_end(ap);
+  fflush(iotrace_file);
+}
+#endif
+
+/*
+** Usage:  io_trace FILENAME
+**
+** Turn I/O tracing on or off.  If FILENAME is not an empty string,
+** I/O tracing begins going into FILENAME. If FILENAME is an empty
+** string, I/O tracing is turned off.
+*/
+static int test_io_trace(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+#if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+          " FILENAME\"", 0);
+    return TCL_ERROR;
+  }
+  if( iotrace_file ){
+    if( iotrace_file!=stdout && iotrace_file!=stderr ){
+      fclose(iotrace_file);
+    }
+    iotrace_file = 0;
+    sqlite3IoTrace = 0;
+  }
+  if( argv[1][0] ){
+    if( strcmp(argv[1],"stdout")==0 ){
+      iotrace_file = stdout;
+    }else if( strcmp(argv[1],"stderr")==0 ){
+      iotrace_file = stderr;
+    }else{
+      iotrace_file = fopen(argv[1], "w");
+    }
+    sqlite3IoTrace = io_trace_callback;
+  }
+#endif
+  return TCL_OK;
+}
+
+
+/*
+** Usage:  sqlite3_exec_printf  DB  FORMAT  STRING
+**
+** Invoke the sqlite3_exec_printf() interface using the open database
+** DB.  The SQL is the string FORMAT.  The format string should contain
+** one %s or %q.  STRING is the value inserted into %s or %q.
+*/
+static int test_exec_printf(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  Tcl_DString str;
+  int rc;
+  char *zErr = 0;
+  char *zSql;
+  char zBuf[30];
+  if( argc!=4 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+       " DB FORMAT STRING", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  Tcl_DStringInit(&str);
+  zSql = sqlite3_mprintf(argv[2], argv[3]);
+  rc = sqlite3_exec(db, zSql, exec_printf_cb, &str, &zErr);
+  sqlite3_free(zSql);
+  sprintf(zBuf, "%d", rc);
+  Tcl_AppendElement(interp, zBuf);
+  Tcl_AppendElement(interp, rc==SQLITE_OK ? Tcl_DStringValue(&str) : zErr);
+  Tcl_DStringFree(&str);
+  if( zErr ) sqlite3_free(zErr);
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  return TCL_OK;
+}
+
+/*
+** Usage:  db_enter DB
+**         db_leave DB
+**
+** Enter or leave the mutex on a database connection.
+*/
+static int db_enter(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+       " DB", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  sqlite3_mutex_enter(db->mutex);
+  return TCL_OK;
+}
+static int db_leave(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+       " DB", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  sqlite3_mutex_leave(db->mutex);
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_exec  DB  SQL
+**
+** Invoke the sqlite3_exec interface using the open database DB
+*/
+static int test_exec(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  Tcl_DString str;
+  int rc;
+  char *zErr = 0;
+  char *zSql;
+  int i, j;
+  char zBuf[30];
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+       " DB SQL", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  Tcl_DStringInit(&str);
+  zSql = sqlite3_mprintf("%s", argv[2]);
+  for(i=j=0; zSql[i];){
+    if( zSql[i]=='%' ){
+      zSql[j++] = (testHexToInt(zSql[i+1])<<4) + testHexToInt(zSql[i+2]);
+      i += 3;
+    }else{
+      zSql[j++] = zSql[i++];
+    }
+  }
+  zSql[j] = 0;
+  rc = sqlite3_exec(db, zSql, exec_printf_cb, &str, &zErr);
+  sqlite3_free(zSql);
+  sprintf(zBuf, "%d", rc);
+  Tcl_AppendElement(interp, zBuf);
+  Tcl_AppendElement(interp, rc==SQLITE_OK ? Tcl_DStringValue(&str) : zErr);
+  Tcl_DStringFree(&str);
+  if( zErr ) sqlite3_free(zErr);
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_exec_nr  DB  SQL
+**
+** Invoke the sqlite3_exec interface using the open database DB.  Discard
+** all results
+*/
+static int test_exec_nr(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  int rc;
+  char *zErr = 0;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+       " DB SQL", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  rc = sqlite3_exec(db, argv[2], 0, 0, &zErr);
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_mprintf_z_test  SEPARATOR  ARG0  ARG1 ...
+**
+** Test the %z format of sqliteMPrintf().  Use multiple mprintf() calls to 
+** concatenate arg0 through argn using separator as the separator.
+** Return the result.
+*/
+static int test_mprintf_z(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  char *zResult = 0;
+  int i;
+
+  for(i=2; i<argc && (i==2 || zResult); i++){
+    zResult = sqlite3MPrintf(0, "%z%s%s", zResult, argv[1], argv[i]);
+  }
+  Tcl_AppendResult(interp, zResult, 0);
+  sqlite3_free(zResult);
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_mprintf_n_test  STRING
+**
+** Test the %n format of sqliteMPrintf().  Return the length of the
+** input string.
+*/
+static int test_mprintf_n(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  char *zStr;
+  int n = 0;
+  zStr = sqlite3MPrintf(0, "%s%n", argv[1], &n);
+  sqlite3_free(zStr);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(n));
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_snprintf_int  SIZE FORMAT  INT
+**
+** Test the of sqlite3_snprintf() routine.  SIZE is the size of the
+** output buffer in bytes.  The maximum size is 100.  FORMAT is the
+** format string.  INT is a single integer argument.  The FORMAT
+** string must require no more than this one integer argument.  If
+** You pass in a format string that requires more than one argument,
+** bad things will happen.
+*/
+static int test_snprintf_int(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  char zStr[100];
+  int n = atoi(argv[1]);
+  const char *zFormat = argv[2];
+  int a1 = atoi(argv[3]);
+  if( n>sizeof(zStr) ) n = sizeof(zStr);
+  sqlite3_snprintf(sizeof(zStr), zStr, "abcdefghijklmnopqrstuvwxyz");
+  sqlite3_snprintf(n, zStr, zFormat, a1);
+  Tcl_AppendResult(interp, zStr, 0);
+  return TCL_OK;
+}
+
+#ifndef SQLITE_OMIT_GET_TABLE
+
+/*
+** Usage:  sqlite3_get_table_printf  DB  FORMAT  STRING  ?--no-counts?
+**
+** Invoke the sqlite3_get_table_printf() interface using the open database
+** DB.  The SQL is the string FORMAT.  The format string should contain
+** one %s or %q.  STRING is the value inserted into %s or %q.
+*/
+static int test_get_table_printf(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  Tcl_DString str;
+  int rc;
+  char *zErr = 0;
+  int nRow, nCol;
+  char **aResult;
+  int i;
+  char zBuf[30];
+  char *zSql;
+  int resCount = -1;
+  if( argc==5 ){
+    if( Tcl_GetInt(interp, argv[4], &resCount) ) return TCL_ERROR;
+  }
+  if( argc!=4 && argc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+       " DB FORMAT STRING ?COUNT?", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  Tcl_DStringInit(&str);
+  zSql = sqlite3_mprintf(argv[2],argv[3]);
+  if( argc==5 ){
+    rc = sqlite3_get_table(db, zSql, &aResult, 0, 0, &zErr);
+  }else{
+    rc = sqlite3_get_table(db, zSql, &aResult, &nRow, &nCol, &zErr);
+    resCount = (nRow+1)*nCol;
+  }
+  sqlite3_free(zSql);
+  sprintf(zBuf, "%d", rc);
+  Tcl_AppendElement(interp, zBuf);
+  if( rc==SQLITE_OK ){
+    if( argc==4 ){
+      sprintf(zBuf, "%d", nRow);
+      Tcl_AppendElement(interp, zBuf);
+      sprintf(zBuf, "%d", nCol);
+      Tcl_AppendElement(interp, zBuf);
+    }
+    for(i=0; i<resCount; i++){
+      Tcl_AppendElement(interp, aResult[i] ? aResult[i] : "NULL");
+    }
+  }else{
+    Tcl_AppendElement(interp, zErr);
+  }
+  sqlite3_free_table(aResult);
+  if( zErr ) sqlite3_free(zErr);
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  return TCL_OK;
+}
+
+#endif /* SQLITE_OMIT_GET_TABLE */
+
+
+/*
+** Usage:  sqlite3_last_insert_rowid DB
+**
+** Returns the integer ROWID of the most recent insert.
+*/
+static int test_last_rowid(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  char zBuf[30];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], " DB\"", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  sprintf(zBuf, "%lld", sqlite3_last_insert_rowid(db));
+  Tcl_AppendResult(interp, zBuf, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:  sqlite3_key DB KEY
+**
+** Set the codec key.
+*/
+static int test_key(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  const char *zKey;
+  int nKey;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FILENAME\"", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  zKey = argv[2];
+  nKey = strlen(zKey);
+#ifdef SQLITE_HAS_CODEC
+  sqlite3_key(db, zKey, nKey);
+#endif
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_rekey DB KEY
+**
+** Change the codec key.
+*/
+static int test_rekey(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  const char *zKey;
+  int nKey;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FILENAME\"", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  zKey = argv[2];
+  nKey = strlen(zKey);
+#ifdef SQLITE_HAS_CODEC
+  sqlite3_rekey(db, zKey, nKey);
+#endif
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_close DB
+**
+** Closes the database opened by sqlite3_open.
+*/
+static int sqlite_test_close(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FILENAME\"", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  rc = sqlite3_close(db);
+  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
+  return TCL_OK;
+}
+
+/*
+** Implementation of the x_coalesce() function.
+** Return the first argument non-NULL argument.
+*/
+static void t1_ifnullFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int i;
+  for(i=0; i<argc; i++){
+    if( SQLITE_NULL!=sqlite3_value_type(argv[i]) ){
+      int n = sqlite3_value_bytes(argv[i]);
+      sqlite3_result_text(context, (char*)sqlite3_value_text(argv[i]),
+          n, SQLITE_TRANSIENT);
+      break;
+    }
+  }
+}
+
+/*
+** These are test functions.    hex8() interprets its argument as
+** UTF8 and returns a hex encoding.  hex16le() interprets its argument
+** as UTF16le and returns a hex encoding.
+*/
+static void hex8Func(sqlite3_context *p, int argc, sqlite3_value **argv){
+  const unsigned char *z;
+  int i;
+  char zBuf[200];
+  z = sqlite3_value_text(argv[0]);
+  for(i=0; i<sizeof(zBuf)/2 - 2 && z[i]; i++){
+    sprintf(&zBuf[i*2], "%02x", z[i]&0xff);
+  }
+  zBuf[i*2] = 0;
+  sqlite3_result_text(p, (char*)zBuf, -1, SQLITE_TRANSIENT);
+}
+#ifndef SQLITE_OMIT_UTF16
+static void hex16Func(sqlite3_context *p, int argc, sqlite3_value **argv){
+  const unsigned short int *z;
+  int i;
+  char zBuf[400];
+  z = sqlite3_value_text16(argv[0]);
+  for(i=0; i<sizeof(zBuf)/4 - 4 && z[i]; i++){
+    sprintf(&zBuf[i*4], "%04x", z[i]&0xff);
+  }
+  zBuf[i*4] = 0;
+  sqlite3_result_text(p, (char*)zBuf, -1, SQLITE_TRANSIENT);
+}
+#endif
+
+/*
+** A structure into which to accumulate text.
+*/
+struct dstr {
+  int nAlloc;  /* Space allocated */
+  int nUsed;   /* Space used */
+  char *z;     /* The space */
+};
+
+/*
+** Append text to a dstr
+*/
+static void dstrAppend(struct dstr *p, const char *z, int divider){
+  int n = strlen(z);
+  if( p->nUsed + n + 2 > p->nAlloc ){
+    char *zNew;
+    p->nAlloc = p->nAlloc*2 + n + 200;
+    zNew = sqlite3_realloc(p->z, p->nAlloc);
+    if( zNew==0 ){
+      sqlite3_free(p->z);
+      memset(p, 0, sizeof(*p));
+      return;
+    }
+    p->z = zNew;
+  }
+  if( divider && p->nUsed>0 ){
+    p->z[p->nUsed++] = divider;
+  }
+  memcpy(&p->z[p->nUsed], z, n+1);
+  p->nUsed += n;
+}
+
+/*
+** Invoked for each callback from sqlite3ExecFunc
+*/
+static int execFuncCallback(void *pData, int argc, char **argv, char **NotUsed){
+  struct dstr *p = (struct dstr*)pData;
+  int i;
+  for(i=0; i<argc; i++){
+    if( argv[i]==0 ){
+      dstrAppend(p, "NULL", ' ');
+    }else{
+      dstrAppend(p, argv[i], ' ');
+    }
+  }
+  return 0;
+}
+
+/*
+** Implementation of the x_sqlite_exec() function.  This function takes
+** a single argument and attempts to execute that argument as SQL code.
+** This is illegal and should set the SQLITE_MISUSE flag on the database.
+**
+** 2004-Jan-07:  We have changed this to make it legal to call sqlite3_exec()
+** from within a function call.  
+** 
+** This routine simulates the effect of having two threads attempt to
+** use the same database at the same time.
+*/
+static void sqlite3ExecFunc(
+  sqlite3_context *context, 
+  int argc,  
+  sqlite3_value **argv
+){
+  struct dstr x;
+  memset(&x, 0, sizeof(x));
+  (void)sqlite3_exec((sqlite3*)sqlite3_user_data(context),
+      (char*)sqlite3_value_text(argv[0]),
+      execFuncCallback, &x, 0);
+  sqlite3_result_text(context, x.z, x.nUsed, SQLITE_TRANSIENT);
+  sqlite3_free(x.z);
+}
+
+/*
+** Implementation of tkt2213func(), a scalar function that takes exactly
+** one argument. It has two interesting features:
+**
+** * It calls sqlite3_value_text() 3 times on the argument sqlite3_value*.
+**   If the three pointers returned are not the same an SQL error is raised.
+**
+** * Otherwise it returns a copy of the text representation of its 
+**   argument in such a way as the VDBE representation is a Mem* cell 
+**   with the MEM_Term flag clear. 
+**
+** Ticket #2213 can therefore be tested by evaluating the following
+** SQL expression:
+**
+**   tkt2213func(tkt2213func('a string'));
+*/
+static void tkt2213Function(
+  sqlite3_context *context, 
+  int argc,  
+  sqlite3_value **argv
+){
+  int nText;
+  unsigned char const *zText1;
+  unsigned char const *zText2;
+  unsigned char const *zText3;
+
+  nText = sqlite3_value_bytes(argv[0]);
+  zText1 = sqlite3_value_text(argv[0]);
+  zText2 = sqlite3_value_text(argv[0]);
+  zText3 = sqlite3_value_text(argv[0]);
+
+  if( zText1!=zText2 || zText2!=zText3 ){
+    sqlite3_result_error(context, "tkt2213 is not fixed", -1);
+  }else{
+    char *zCopy = (char *)sqlite3_malloc(nText);
+    memcpy(zCopy, zText1, nText);
+    sqlite3_result_text(context, zCopy, nText, sqlite3_free);
+  }
+}
+
+/*
+** The following SQL function takes 4 arguments.  The 2nd and
+** 4th argument must be one of these strings:  'text', 'text16',
+** or 'blob' corresponding to API functions
+**
+**      sqlite3_value_text()
+**      sqlite3_value_text16()
+**      sqlite3_value_blob()
+**
+** The third argument is a string, either 'bytes' or 'bytes16' or 'noop',
+** corresponding to APIs:
+**
+**      sqlite3_value_bytes()
+**      sqlite3_value_bytes16()
+**      noop
+**
+** The APIs designated by the 2nd through 4th arguments are applied
+** to the first argument in order.  If the pointers returned by the
+** second and fourth are different, this routine returns 1.  Otherwise,
+** this routine returns 0.
+**
+** This function is used to test to see when returned pointers from
+** the _text(), _text16() and _blob() APIs become invalidated.
+*/
+static void ptrChngFunction(
+  sqlite3_context *context, 
+  int argc,  
+  sqlite3_value **argv
+){
+  const void *p1, *p2;
+  const char *zCmd;
+  if( argc!=4 ) return;
+  zCmd = (const char*)sqlite3_value_text(argv[1]);
+  if( zCmd==0 ) return;
+  if( strcmp(zCmd,"text")==0 ){
+    p1 = (const void*)sqlite3_value_text(argv[0]);
+#ifndef SQLITE_OMIT_UTF16
+  }else if( strcmp(zCmd, "text16")==0 ){
+    p1 = (const void*)sqlite3_value_text16(argv[0]);
+#endif
+  }else if( strcmp(zCmd, "blob")==0 ){
+    p1 = (const void*)sqlite3_value_blob(argv[0]);
+  }else{
+    return;
+  }
+  zCmd = (const char*)sqlite3_value_text(argv[2]);
+  if( zCmd==0 ) return;
+  if( strcmp(zCmd,"bytes")==0 ){
+    sqlite3_value_bytes(argv[0]);
+#ifndef SQLITE_OMIT_UTF16
+  }else if( strcmp(zCmd, "bytes16")==0 ){
+    sqlite3_value_bytes16(argv[0]);
+#endif
+  }else if( strcmp(zCmd, "noop")==0 ){
+    /* do nothing */
+  }else{
+    return;
+  }
+  zCmd = (const char*)sqlite3_value_text(argv[3]);
+  if( zCmd==0 ) return;
+  if( strcmp(zCmd,"text")==0 ){
+    p2 = (const void*)sqlite3_value_text(argv[0]);
+#ifndef SQLITE_OMIT_UTF16
+  }else if( strcmp(zCmd, "text16")==0 ){
+    p2 = (const void*)sqlite3_value_text16(argv[0]);
+#endif
+  }else if( strcmp(zCmd, "blob")==0 ){
+    p2 = (const void*)sqlite3_value_blob(argv[0]);
+  }else{
+    return;
+  }
+  sqlite3_result_int(context, p1!=p2);
+}
+
+
+/*
+** Usage:  sqlite_test_create_function DB
+**
+** Call the sqlite3_create_function API on the given database in order
+** to create a function named "x_coalesce".  This function does the same thing
+** as the "coalesce" function.  This function also registers an SQL function
+** named "x_sqlite_exec" that invokes sqlite3_exec().  Invoking sqlite3_exec()
+** in this way is illegal recursion and should raise an SQLITE_MISUSE error.
+** The effect is similar to trying to use the same database connection from
+** two threads at the same time.
+**
+** The original motivation for this routine was to be able to call the
+** sqlite3_create_function function while a query is in progress in order
+** to test the SQLITE_MISUSE detection logic.
+*/
+static int test_create_function(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  int rc;
+  sqlite3 *db;
+  extern void Md5_Register(sqlite3*);
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " DB\"", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  rc = sqlite3_create_function(db, "x_coalesce", -1, SQLITE_ANY, 0, 
+        t1_ifnullFunc, 0, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "hex8", 1, SQLITE_ANY, 0, 
+          hex8Func, 0, 0);
+  }
+#ifndef SQLITE_OMIT_UTF16
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "hex16", 1, SQLITE_ANY, 0, 
+          hex16Func, 0, 0);
+  }
+#endif
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "tkt2213func", 1, SQLITE_ANY, 0, 
+          tkt2213Function, 0, 0);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "pointer_change", 4, SQLITE_ANY, 0, 
+          ptrChngFunction, 0, 0);
+  }
+
+#ifndef SQLITE_OMIT_UTF16
+  /* Use the sqlite3_create_function16() API here. Mainly for fun, but also 
+  ** because it is not tested anywhere else. */
+  if( rc==SQLITE_OK ){
+    const void *zUtf16;
+    sqlite3_value *pVal;
+    sqlite3_mutex_enter(db->mutex);
+    pVal = sqlite3ValueNew(db);
+    sqlite3ValueSetStr(pVal, -1, "x_sqlite_exec", SQLITE_UTF8, SQLITE_STATIC);
+    zUtf16 = sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
+    if( db->mallocFailed ){
+      rc = SQLITE_NOMEM;
+    }else{
+      rc = sqlite3_create_function16(db, zUtf16, 
+                1, SQLITE_UTF16, db, sqlite3ExecFunc, 0, 0);
+    }
+    sqlite3ValueFree(pVal);
+    sqlite3_mutex_leave(db->mutex);
+  }
+#endif
+
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  Tcl_SetResult(interp, (char *)t1ErrorName(rc), 0);
+  return TCL_OK;
+}
+
+/*
+** Routines to implement the x_count() aggregate function.
+**
+** x_count() counts the number of non-null arguments.  But there are
+** some twists for testing purposes.
+**
+** If the argument to x_count() is 40 then a UTF-8 error is reported
+** on the step function.  If x_count(41) is seen, then a UTF-16 error
+** is reported on the step function.  If the total count is 42, then
+** a UTF-8 error is reported on the finalize function.
+*/
+typedef struct t1CountCtx t1CountCtx;
+struct t1CountCtx {
+  int n;
+};
+static void t1CountStep(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  t1CountCtx *p;
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0]) ) && p ){
+    p->n++;
+  }
+  if( argc>0 ){
+    int v = sqlite3_value_int(argv[0]);
+    if( v==40 ){
+      sqlite3_result_error(context, "value of 40 handed to x_count", -1);
+#ifndef SQLITE_OMIT_UTF16
+    }else if( v==41 ){
+      const char zUtf16ErrMsg[] = { 0, 0x61, 0, 0x62, 0, 0x63, 0, 0, 0};
+      sqlite3_result_error16(context, &zUtf16ErrMsg[1-SQLITE_BIGENDIAN], -1);
+#endif
+    }
+  }
+}   
+static void t1CountFinalize(sqlite3_context *context){
+  t1CountCtx *p;
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  if( p ){
+    if( p->n==42 ){
+      sqlite3_result_error(context, "x_count totals to 42", -1);
+    }else{
+      sqlite3_result_int(context, p ? p->n : 0);
+    }
+  }
+}
+
+static void legacyCountStep(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  /* no-op */
+}
+static void legacyCountFinalize(sqlite3_context *context){
+  sqlite3_result_int(context, sqlite3_aggregate_count(context));
+}
+
+/*
+** Usage:  sqlite3_create_aggregate DB
+**
+** Call the sqlite3_create_function API on the given database in order
+** to create a function named "x_count".  This function is similar
+** to the built-in count() function, with a few special quirks
+** for testing the sqlite3_result_error() APIs.
+**
+** The original motivation for this routine was to be able to call the
+** sqlite3_create_aggregate function while a query is in progress in order
+** to test the SQLITE_MISUSE detection logic.  See misuse.test.
+**
+** This routine was later extended to test the use of sqlite3_result_error()
+** within aggregate functions.
+**
+** Later: It is now also extended to register the aggregate function
+** "legacy_count()" with the supplied database handle. This is used
+** to test the deprecated sqlite3_aggregate_count() API.
+*/
+static int test_create_aggregate(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FILENAME\"", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  rc = sqlite3_create_function(db, "x_count", 0, SQLITE_UTF8, 0, 0,
+      t1CountStep,t1CountFinalize);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "x_count", 1, SQLITE_UTF8, 0, 0,
+        t1CountStep,t1CountFinalize);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "legacy_count", 0, SQLITE_ANY, 0, 0,
+        legacyCountStep, legacyCountFinalize
+    );
+  }
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  Tcl_SetResult(interp, (char *)t1ErrorName(rc), 0);
+  return TCL_OK;
+}
+
+
+/*
+** Usage:  printf TEXT
+**
+** Send output to printf.  Use this rather than puts to merge the output
+** in the correct sequence with debugging printfs inserted into C code.
+** Puts uses a separate buffer and debugging statements will be out of
+** sequence if it is used.
+*/
+static int test_printf(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " TEXT\"", 0);
+    return TCL_ERROR;
+  }
+  printf("%s\n", argv[1]);
+  return TCL_OK;
+}
+
+
+
+/*
+** Usage:  sqlite3_mprintf_int FORMAT INTEGER INTEGER INTEGER
+**
+** Call mprintf with three integer arguments
+*/
+static int sqlite3_mprintf_int(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  int a[3], i;
+  char *z;
+  if( argc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FORMAT INT INT INT\"", 0);
+    return TCL_ERROR;
+  }
+  for(i=2; i<5; i++){
+    if( Tcl_GetInt(interp, argv[i], &a[i-2]) ) return TCL_ERROR;
+  }
+  z = sqlite3_mprintf(argv[1], a[0], a[1], a[2]);
+  Tcl_AppendResult(interp, z, 0);
+  sqlite3_free(z);
+  return TCL_OK;
+}
+
+/*
+** If zNum represents an integer that will fit in 64-bits, then set
+** *pValue to that integer and return true.  Otherwise return false.
+*/
+static int sqlite3GetInt64(const char *zNum, i64 *pValue){
+  if( sqlite3FitsIn64Bits(zNum, 0) ){
+    sqlite3Atoi64(zNum, pValue);
+    return 1;
+  }
+  return 0;
+}
+
+/*
+** Usage:  sqlite3_mprintf_int64 FORMAT INTEGER INTEGER INTEGER
+**
+** Call mprintf with three 64-bit integer arguments
+*/
+static int sqlite3_mprintf_int64(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  int i;
+  sqlite_int64 a[3];
+  char *z;
+  if( argc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FORMAT INT INT INT\"", 0);
+    return TCL_ERROR;
+  }
+  for(i=2; i<5; i++){
+    if( !sqlite3GetInt64(argv[i], &a[i-2]) ){
+      Tcl_AppendResult(interp, "argument is not a valid 64-bit integer", 0);
+      return TCL_ERROR;
+    }
+  }
+  z = sqlite3_mprintf(argv[1], a[0], a[1], a[2]);
+  Tcl_AppendResult(interp, z, 0);
+  sqlite3_free(z);
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_mprintf_str FORMAT INTEGER INTEGER STRING
+**
+** Call mprintf with two integer arguments and one string argument
+*/
+static int sqlite3_mprintf_str(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  int a[3], i;
+  char *z;
+  if( argc<4 || argc>5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FORMAT INT INT ?STRING?\"", 0);
+    return TCL_ERROR;
+  }
+  for(i=2; i<4; i++){
+    if( Tcl_GetInt(interp, argv[i], &a[i-2]) ) return TCL_ERROR;
+  }
+  z = sqlite3_mprintf(argv[1], a[0], a[1], argc>4 ? argv[4] : NULL);
+  Tcl_AppendResult(interp, z, 0);
+  sqlite3_free(z);
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_snprintf_str INTEGER FORMAT INTEGER INTEGER STRING
+**
+** Call mprintf with two integer arguments and one string argument
+*/
+static int sqlite3_snprintf_str(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  int a[3], i;
+  int n;
+  char *z;
+  if( argc<5 || argc>6 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " INT FORMAT INT INT ?STRING?\"", 0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetInt(interp, argv[1], &n) ) return TCL_ERROR;
+  if( n<0 ){
+    Tcl_AppendResult(interp, "N must be non-negative", 0);
+    return TCL_ERROR;
+  }
+  for(i=3; i<5; i++){
+    if( Tcl_GetInt(interp, argv[i], &a[i-3]) ) return TCL_ERROR;
+  }
+  z = sqlite3_malloc( n+1 );
+  sqlite3_snprintf(n, z, argv[2], a[0], a[1], argc>4 ? argv[5] : NULL);
+  Tcl_AppendResult(interp, z, 0);
+  sqlite3_free(z);
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_mprintf_double FORMAT INTEGER INTEGER DOUBLE
+**
+** Call mprintf with two integer arguments and one double argument
+*/
+static int sqlite3_mprintf_double(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  int a[3], i;
+  double r;
+  char *z;
+  if( argc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FORMAT INT INT DOUBLE\"", 0);
+    return TCL_ERROR;
+  }
+  for(i=2; i<4; i++){
+    if( Tcl_GetInt(interp, argv[i], &a[i-2]) ) return TCL_ERROR;
+  }
+  if( Tcl_GetDouble(interp, argv[4], &r) ) return TCL_ERROR;
+  z = sqlite3_mprintf(argv[1], a[0], a[1], r);
+  Tcl_AppendResult(interp, z, 0);
+  sqlite3_free(z);
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_mprintf_scaled FORMAT DOUBLE DOUBLE
+**
+** Call mprintf with a single double argument which is the product of the
+** two arguments given above.  This is used to generate overflow and underflow
+** doubles to test that they are converted properly.
+*/
+static int sqlite3_mprintf_scaled(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  int i;
+  double r[2];
+  char *z;
+  if( argc!=4 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FORMAT DOUBLE DOUBLE\"", 0);
+    return TCL_ERROR;
+  }
+  for(i=2; i<4; i++){
+    if( Tcl_GetDouble(interp, argv[i], &r[i-2]) ) return TCL_ERROR;
+  }
+  z = sqlite3_mprintf(argv[1], r[0]*r[1]);
+  Tcl_AppendResult(interp, z, 0);
+  sqlite3_free(z);
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_mprintf_stronly FORMAT STRING
+**
+** Call mprintf with a single double argument which is the product of the
+** two arguments given above.  This is used to generate overflow and underflow
+** doubles to test that they are converted properly.
+*/
+static int sqlite3_mprintf_stronly(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  char *z;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FORMAT STRING\"", 0);
+    return TCL_ERROR;
+  }
+  z = sqlite3_mprintf(argv[1], argv[2]);
+  Tcl_AppendResult(interp, z, 0);
+  sqlite3_free(z);
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_mprintf_hexdouble FORMAT HEX
+**
+** Call mprintf with a single double argument which is derived from the
+** hexadecimal encoding of an IEEE double.
+*/
+static int sqlite3_mprintf_hexdouble(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  char *z;
+  double r;
+  unsigned int x1, x2;
+  sqlite_uint64 d;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FORMAT STRING\"", 0);
+    return TCL_ERROR;
+  }
+  if( sscanf(argv[2], "%08x%08x", &x2, &x1)!=2 ){
+    Tcl_AppendResult(interp, "2nd argument should be 16-characters of hex", 0);
+    return TCL_ERROR;
+  }
+  d = x2;
+  d = (d<<32) + x1;
+  memcpy(&r, &d, sizeof(r));
+  z = sqlite3_mprintf(argv[1], r);
+  Tcl_AppendResult(interp, z, 0);
+  sqlite3_free(z);
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_enable_shared_cache      BOOLEAN
+**
+*/
+#if !defined(SQLITE_OMIT_SHARED_CACHE)
+static int test_enable_shared(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  int rc;
+  int enable;
+  int ret = 0;
+  extern int sqlite3SharedCacheEnabled;
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "BOOLEAN");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetBooleanFromObj(interp, objv[1], &enable) ){
+    return TCL_ERROR;
+  }
+  ret = sqlite3SharedCacheEnabled;
+  rc = sqlite3_enable_shared_cache(enable);
+  if( rc!=SQLITE_OK ){
+    Tcl_SetResult(interp, (char *)sqlite3ErrStr(rc), TCL_STATIC);
+    return TCL_ERROR;
+  }
+  Tcl_SetObjResult(interp, Tcl_NewBooleanObj(ret));
+  return TCL_OK;
+}
+#endif
+
+
+
+/*
+** Usage: sqlite3_extended_result_codes   DB    BOOLEAN
+**
+*/
+static int test_extended_result_codes(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  int enable;
+  sqlite3 *db;
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB BOOLEAN");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  if( Tcl_GetBooleanFromObj(interp, objv[2], &enable) ) return TCL_ERROR;
+  sqlite3_extended_result_codes(db, enable);
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_libversion_number
+**
+*/
+static int test_libversion_number(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(sqlite3_libversion_number()));
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_table_column_metadata DB dbname tblname colname
+**
+*/
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+static int test_table_column_metadata(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3 *db;
+  const char *zDb;
+  const char *zTbl;
+  const char *zCol;
+  int rc;
+  Tcl_Obj *pRet;
+
+  const char *zDatatype;
+  const char *zCollseq;
+  int notnull;
+  int primarykey;
+  int autoincrement;
+
+  if( objc!=5 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB dbname tblname colname");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  zDb = Tcl_GetString(objv[2]);
+  zTbl = Tcl_GetString(objv[3]);
+  zCol = Tcl_GetString(objv[4]);
+
+  if( strlen(zDb)==0 ) zDb = 0;
+
+  rc = sqlite3_table_column_metadata(db, zDb, zTbl, zCol, 
+      &zDatatype, &zCollseq, &notnull, &primarykey, &autoincrement);
+
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, sqlite3_errmsg(db), 0);
+    return TCL_ERROR;
+  }
+
+  pRet = Tcl_NewObj();
+  Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zDatatype, -1));
+  Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zCollseq, -1));
+  Tcl_ListObjAppendElement(0, pRet, Tcl_NewIntObj(notnull));
+  Tcl_ListObjAppendElement(0, pRet, Tcl_NewIntObj(primarykey));
+  Tcl_ListObjAppendElement(0, pRet, Tcl_NewIntObj(autoincrement));
+  Tcl_SetObjResult(interp, pRet);
+
+  return TCL_OK;
+}
+#endif
+
+#ifndef SQLITE_OMIT_INCRBLOB
+
+/*
+** sqlite3_blob_read  CHANNEL OFFSET N
+**
+**   This command is used to test the sqlite3_blob_read() in ways that
+**   the Tcl channel interface does not. The first argument should
+**   be the name of a valid channel created by the [incrblob] method
+**   of a database handle. This function calls sqlite3_blob_read()
+**   to read N bytes from offset OFFSET from the underlying SQLite
+**   blob handle.
+**
+**   On success, a byte-array object containing the read data is 
+**   returned. On failure, the interpreter result is set to the
+**   text representation of the returned error code (i.e. "SQLITE_NOMEM")
+**   and a Tcl exception is thrown.
+*/
+static int test_blob_read(
+  ClientData clientData, /* Not used */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  Tcl_Channel channel;
+  ClientData instanceData;
+  sqlite3_blob *pBlob;
+  int notUsed;
+  int nByte;
+  int iOffset;
+  unsigned char *zBuf;
+  int rc;
+  
+  if( objc!=4 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "CHANNEL OFFSET N");
+    return TCL_ERROR;
+  }
+
+  channel = Tcl_GetChannel(interp, Tcl_GetString(objv[1]), &notUsed);
+  if( !channel
+   || TCL_OK!=Tcl_GetIntFromObj(interp, objv[2], &iOffset)
+   || TCL_OK!=Tcl_GetIntFromObj(interp, objv[3], &nByte)
+   || nByte<0 || iOffset<0
+  ){ 
+    return TCL_ERROR;
+  }
+
+  instanceData = Tcl_GetChannelInstanceData(channel);
+  pBlob = *((sqlite3_blob **)instanceData);
+
+  zBuf = (unsigned char *)Tcl_Alloc(nByte);
+  rc = sqlite3_blob_read(pBlob, zBuf, nByte, iOffset);
+  if( rc==SQLITE_OK ){
+    Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(zBuf, nByte));
+  }else{
+    Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  }
+  Tcl_Free((char *)zBuf);
+
+  return (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
+}
+
+/*
+** sqlite3_blob_write CHANNEL OFFSET DATA
+**
+**   This command is used to test the sqlite3_blob_write() in ways that
+**   the Tcl channel interface does not. The first argument should
+**   be the name of a valid channel created by the [incrblob] method
+**   of a database handle. This function calls sqlite3_blob_write()
+**   to write the DATA byte-array to the underlying SQLite blob handle.
+**   at offset OFFSET.
+**
+**   On success, an empty string is returned. On failure, the interpreter
+**   result is set to the text representation of the returned error code 
+**   (i.e. "SQLITE_NOMEM") and a Tcl exception is thrown.
+*/
+static int test_blob_write(
+  ClientData clientData, /* Not used */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  Tcl_Channel channel;
+  ClientData instanceData;
+  sqlite3_blob *pBlob;
+  int notUsed;
+  int iOffset;
+  int rc;
+
+  unsigned char *zBuf;
+  int nBuf;
+  
+  if( objc!=4 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "CHANNEL OFFSET DATA");
+    return TCL_ERROR;
+  }
+
+  channel = Tcl_GetChannel(interp, Tcl_GetString(objv[1]), &notUsed);
+  if( !channel
+   || TCL_OK!=Tcl_GetIntFromObj(interp, objv[2], &iOffset)
+   || iOffset<0
+  ){ 
+    return TCL_ERROR;
+  }
+
+  instanceData = Tcl_GetChannelInstanceData(channel);
+  pBlob = *((sqlite3_blob **)instanceData);
+
+  zBuf = Tcl_GetByteArrayFromObj(objv[3], &nBuf);
+  rc = sqlite3_blob_write(pBlob, zBuf, nBuf, iOffset);
+  if( rc!=SQLITE_OK ){
+    Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  }
+
+  return (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
+}
+#endif
+
+/*
+** Usage: sqlite3_create_collation_v2 DB-HANDLE NAME CMP-PROC DEL-PROC
+**
+**   This Tcl proc is used for testing the experimental
+**   sqlite3_create_collation_v2() interface.
+*/
+struct TestCollationX {
+  Tcl_Interp *interp;
+  Tcl_Obj *pCmp;
+  Tcl_Obj *pDel;
+};
+typedef struct TestCollationX TestCollationX;
+static void testCreateCollationDel(void *pCtx){
+  TestCollationX *p = (TestCollationX *)pCtx;
+
+  int rc = Tcl_EvalObjEx(p->interp, p->pDel, TCL_EVAL_DIRECT|TCL_EVAL_GLOBAL);
+  if( rc!=TCL_OK ){
+    Tcl_BackgroundError(p->interp);
+  }
+
+  Tcl_DecrRefCount(p->pCmp);
+  Tcl_DecrRefCount(p->pDel);
+  sqlite3_free((void *)p);
+}
+static int testCreateCollationCmp(
+  void *pCtx,
+  int nLeft,
+  const void *zLeft,
+  int nRight,
+  const void *zRight
+){
+  TestCollationX *p = (TestCollationX *)pCtx;
+  Tcl_Obj *pScript = Tcl_DuplicateObj(p->pCmp);
+  int iRes = 0;
+
+  Tcl_IncrRefCount(pScript);
+  Tcl_ListObjAppendElement(0, pScript, Tcl_NewStringObj((char *)zLeft, nLeft));
+  Tcl_ListObjAppendElement(0, pScript, Tcl_NewStringObj((char *)zRight,nRight));
+
+  if( TCL_OK!=Tcl_EvalObjEx(p->interp, pScript, TCL_EVAL_DIRECT|TCL_EVAL_GLOBAL)
+   || TCL_OK!=Tcl_GetIntFromObj(p->interp, Tcl_GetObjResult(p->interp), &iRes)
+  ){
+    Tcl_BackgroundError(p->interp);
+  }
+  Tcl_DecrRefCount(pScript);
+
+  return iRes;
+}
+static int test_create_collation_v2(
+  ClientData clientData, /* Not used */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  TestCollationX *p;
+  sqlite3 *db;
+  int rc;
+
+  if( objc!=5 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB-HANDLE NAME CMP-PROC DEL-PROC");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+
+  p = (TestCollationX *)sqlite3_malloc(sizeof(TestCollationX));
+  p->pCmp = objv[3];
+  p->pDel = objv[4];
+  p->interp = interp;
+  Tcl_IncrRefCount(p->pCmp);
+  Tcl_IncrRefCount(p->pDel);
+
+  rc = sqlite3_create_collation_v2(db, Tcl_GetString(objv[2]), 16, 
+      (void *)p, testCreateCollationCmp, testCreateCollationDel
+  );
+  if( rc!=SQLITE_MISUSE ){
+    Tcl_AppendResult(interp, "sqlite3_create_collate_v2() failed to detect "
+      "an invalid encoding", (char*)0);
+    return TCL_ERROR;
+  }
+  rc = sqlite3_create_collation_v2(db, Tcl_GetString(objv[2]), SQLITE_UTF8, 
+      (void *)p, testCreateCollationCmp, testCreateCollationDel
+  );
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_load_extension DB-HANDLE FILE ?PROC?
+*/
+static int test_load_extension(
+  ClientData clientData, /* Not used */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  Tcl_CmdInfo cmdInfo;
+  sqlite3 *db;
+  int rc;
+  char *zDb;
+  char *zFile;
+  char *zProc = 0;
+  char *zErr = 0;
+
+  if( objc!=4 && objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB-HANDLE FILE ?PROC?");
+    return TCL_ERROR;
+  }
+  zDb = Tcl_GetString(objv[1]);
+  zFile = Tcl_GetString(objv[2]);
+  if( objc==4 ){
+    zProc = Tcl_GetString(objv[3]);
+  }
+
+  /* Extract the C database handle from the Tcl command name */
+  if( !Tcl_GetCommandInfo(interp, zDb, &cmdInfo) ){
+    Tcl_AppendResult(interp, "command not found: ", zDb, (char*)0);
+    return TCL_ERROR;
+  }
+  db = ((struct SqliteDb*)cmdInfo.objClientData)->db;
+  assert(db);
+
+  /* Call the underlying C function. If an error occurs, set rc to 
+  ** TCL_ERROR and load any error string into the interpreter. If no 
+  ** error occurs, set rc to TCL_OK.
+  */
+#ifdef SQLITE_OMIT_LOAD_EXTENSION
+  rc = SQLITE_ERROR;
+  zErr = sqlite3_mprintf("this build omits sqlite3_load_extension()");
+#else
+  rc = sqlite3_load_extension(db, zFile, zProc, &zErr);
+#endif
+  if( rc!=SQLITE_OK ){
+    Tcl_SetResult(interp, zErr ? zErr : "", TCL_VOLATILE);
+    rc = TCL_ERROR;
+  }else{
+    rc = TCL_OK;
+  }
+  sqlite3_free(zErr);
+
+  return rc;
+}
+
+/*
+** Usage: sqlite3_enable_load_extension DB-HANDLE ONOFF
+*/
+static int test_enable_load(
+  ClientData clientData, /* Not used */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  Tcl_CmdInfo cmdInfo;
+  sqlite3 *db;
+  char *zDb;
+  int onoff;
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB-HANDLE ONOFF");
+    return TCL_ERROR;
+  }
+  zDb = Tcl_GetString(objv[1]);
+
+  /* Extract the C database handle from the Tcl command name */
+  if( !Tcl_GetCommandInfo(interp, zDb, &cmdInfo) ){
+    Tcl_AppendResult(interp, "command not found: ", zDb, (char*)0);
+    return TCL_ERROR;
+  }
+  db = ((struct SqliteDb*)cmdInfo.objClientData)->db;
+  assert(db);
+
+  /* Get the onoff parameter */
+  if( Tcl_GetBooleanFromObj(interp, objv[2], &onoff) ){
+    return TCL_ERROR;
+  }
+
+#ifdef SQLITE_OMIT_LOAD_EXTENSION
+  Tcl_AppendResult(interp, "this build omits sqlite3_load_extension()");
+  return TCL_ERROR;
+#else
+  sqlite3_enable_load_extension(db, onoff);
+  return TCL_OK;
+#endif
+}
+
+/*
+** Usage:  sqlite_abort
+**
+** Shutdown the process immediately.  This is not a clean shutdown.
+** This command is used to test the recoverability of a database in
+** the event of a program crash.
+*/
+static int sqlite_abort(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  assert( interp==0 );   /* This will always fail */
+  return TCL_OK;
+}
+
+/*
+** The following routine is a user-defined SQL function whose purpose
+** is to test the sqlite_set_result() API.
+*/
+static void testFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  while( argc>=2 ){
+    const char *zArg0 = (char*)sqlite3_value_text(argv[0]);
+    if( zArg0 ){
+      if( 0==sqlite3StrICmp(zArg0, "int") ){
+        sqlite3_result_int(context, sqlite3_value_int(argv[1]));
+      }else if( sqlite3StrICmp(zArg0,"int64")==0 ){
+        sqlite3_result_int64(context, sqlite3_value_int64(argv[1]));
+      }else if( sqlite3StrICmp(zArg0,"string")==0 ){
+        sqlite3_result_text(context, (char*)sqlite3_value_text(argv[1]), -1,
+            SQLITE_TRANSIENT);
+      }else if( sqlite3StrICmp(zArg0,"double")==0 ){
+        sqlite3_result_double(context, sqlite3_value_double(argv[1]));
+      }else if( sqlite3StrICmp(zArg0,"null")==0 ){
+        sqlite3_result_null(context);
+      }else if( sqlite3StrICmp(zArg0,"value")==0 ){
+        sqlite3_result_value(context, argv[sqlite3_value_int(argv[1])]);
+      }else{
+        goto error_out;
+      }
+    }else{
+      goto error_out;
+    }
+    argc -= 2;
+    argv += 2;
+  }
+  return;
+
+error_out:
+  sqlite3_result_error(context,"first argument should be one of: "
+      "int int64 string double null value", -1);
+}
+
+/*
+** Usage:   sqlite_register_test_function  DB  NAME
+**
+** Register the test SQL function on the database DB under the name NAME.
+*/
+static int test_register_func(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  int rc;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+       " DB FUNCTION-NAME", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  rc = sqlite3_create_function(db, argv[2], -1, SQLITE_UTF8, 0, 
+      testFunc, 0, 0);
+  if( rc!=0 ){
+    Tcl_AppendResult(interp, sqlite3ErrStr(rc), 0);
+    return TCL_ERROR;
+  }
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_finalize  STMT 
+**
+** Finalize a statement handle.
+*/
+static int test_finalize(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int rc;
+  sqlite3 *db = 0;
+
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " <STMT>", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+
+  if( pStmt ){
+    db = StmtToDb(pStmt);
+  }
+  rc = sqlite3_finalize(pStmt);
+  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
+  if( db && sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_next_stmt  DB  STMT
+**
+** Return the next statment in sequence after STMT.
+*/
+static int test_next_stmt(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  sqlite3 *db = 0;
+  char zBuf[50];
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " DB STMT", 0);
+    return TCL_ERROR;
+  }
+
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  if( getStmtPointer(interp, Tcl_GetString(objv[2]), &pStmt) ) return TCL_ERROR;
+  pStmt = sqlite3_next_stmt(db, pStmt);
+  if( pStmt ){
+    if( sqlite3TestMakePointerStr(interp, zBuf, pStmt) ) return TCL_ERROR;
+    Tcl_AppendResult(interp, zBuf, 0);
+  }
+  return TCL_OK;
+}
+
+
+/*
+** Usage:  sqlite3_reset  STMT 
+**
+** Reset a statement handle.
+*/
+static int test_reset(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int rc;
+
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " <STMT>", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+
+  rc = sqlite3_reset(pStmt);
+  if( pStmt && sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ){
+    return TCL_ERROR;
+  }
+  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
+/*
+  if( rc ){
+    return TCL_ERROR;
+  }
+*/
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_expired STMT 
+**
+** Return TRUE if a recompilation of the statement is recommended.
+*/
+static int test_expired(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " <STMT>", 0);
+    return TCL_ERROR;
+  }
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  Tcl_SetObjResult(interp, Tcl_NewBooleanObj(sqlite3_expired(pStmt)));
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_transfer_bindings FROMSTMT TOSTMT
+**
+** Transfer all bindings from FROMSTMT over to TOSTMT
+*/
+static int test_transfer_bind(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt1, *pStmt2;
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " FROM-STMT TO-STMT", 0);
+    return TCL_ERROR;
+  }
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt1)) return TCL_ERROR;
+  if( getStmtPointer(interp, Tcl_GetString(objv[2]), &pStmt2)) return TCL_ERROR;
+  Tcl_SetObjResult(interp, 
+     Tcl_NewIntObj(sqlite3_transfer_bindings(pStmt1,pStmt2)));
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_changes DB
+**
+** Return the number of changes made to the database by the last SQL
+** execution.
+*/
+static int test_changes(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+       Tcl_GetString(objv[0]), " DB", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(sqlite3_changes(db)));
+  return TCL_OK;
+}
+
+/*
+** This is the "static_bind_value" that variables are bound to when
+** the FLAG option of sqlite3_bind is "static"
+*/
+static char *sqlite_static_bind_value = 0;
+static int sqlite_static_bind_nbyte = 0;
+
+/*
+** Usage:  sqlite3_bind  VM  IDX  VALUE  FLAGS
+**
+** Sets the value of the IDX-th occurance of "?" in the original SQL
+** string.  VALUE is the new value.  If FLAGS=="null" then VALUE is
+** ignored and the value is set to NULL.  If FLAGS=="static" then
+** the value is set to the value of a static variable named
+** "sqlite_static_bind_value".  If FLAGS=="normal" then a copy
+** of the VALUE is made.  If FLAGS=="blob10" then a VALUE is ignored
+** an a 10-byte blob "abc\000xyz\000pq" is inserted.
+*/
+static int test_bind(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3_stmt *pStmt;
+  int rc;
+  int idx;
+  if( argc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+       " VM IDX VALUE (null|static|normal)\"", 0);
+    return TCL_ERROR;
+  }
+  if( getStmtPointer(interp, argv[1], &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetInt(interp, argv[2], &idx) ) return TCL_ERROR;
+  if( strcmp(argv[4],"null")==0 ){
+    rc = sqlite3_bind_null(pStmt, idx);
+  }else if( strcmp(argv[4],"static")==0 ){
+    rc = sqlite3_bind_text(pStmt, idx, sqlite_static_bind_value, -1, 0);
+  }else if( strcmp(argv[4],"static-nbytes")==0 ){
+    rc = sqlite3_bind_text(pStmt, idx, sqlite_static_bind_value,
+                                       sqlite_static_bind_nbyte, 0);
+  }else if( strcmp(argv[4],"normal")==0 ){
+    rc = sqlite3_bind_text(pStmt, idx, argv[3], -1, SQLITE_TRANSIENT);
+  }else if( strcmp(argv[4],"blob10")==0 ){
+    rc = sqlite3_bind_text(pStmt, idx, "abc\000xyz\000pq", 10, SQLITE_STATIC);
+  }else{
+    Tcl_AppendResult(interp, "4th argument should be "
+        "\"null\" or \"static\" or \"normal\"", 0);
+    return TCL_ERROR;
+  }
+  if( sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ) return TCL_ERROR;
+  if( rc ){
+    char zBuf[50];
+    sprintf(zBuf, "(%d) ", rc);
+    Tcl_AppendResult(interp, zBuf, sqlite3ErrStr(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Usage: add_test_collate <db ptr> <utf8> <utf16le> <utf16be>
+**
+** This function is used to test that SQLite selects the correct collation
+** sequence callback when multiple versions (for different text encodings)
+** are available.
+**
+** Calling this routine registers the collation sequence "test_collate"
+** with database handle <db>. The second argument must be a list of three
+** boolean values. If the first is true, then a version of test_collate is
+** registered for UTF-8, if the second is true, a version is registered for
+** UTF-16le, if the third is true, a UTF-16be version is available.
+** Previous versions of test_collate are deleted.
+**
+** The collation sequence test_collate is implemented by calling the
+** following TCL script:
+**
+**   "test_collate <enc> <lhs> <rhs>"
+**
+** The <lhs> and <rhs> are the two values being compared, encoded in UTF-8.
+** The <enc> parameter is the encoding of the collation function that
+** SQLite selected to call. The TCL test script implements the
+** "test_collate" proc.
+**
+** Note that this will only work with one intepreter at a time, as the
+** interp pointer to use when evaluating the TCL script is stored in
+** pTestCollateInterp.
+*/
+static Tcl_Interp* pTestCollateInterp;
+static int test_collate_func(
+  void *pCtx, 
+  int nA, const void *zA,
+  int nB, const void *zB
+){
+  Tcl_Interp *i = pTestCollateInterp;
+  int encin = (int)pCtx;
+  int res;
+  int n;
+
+  sqlite3_value *pVal;
+  Tcl_Obj *pX;
+
+  pX = Tcl_NewStringObj("test_collate", -1);
+  Tcl_IncrRefCount(pX);
+
+  switch( encin ){
+    case SQLITE_UTF8:
+      Tcl_ListObjAppendElement(i,pX,Tcl_NewStringObj("UTF-8",-1));
+      break;
+    case SQLITE_UTF16LE:
+      Tcl_ListObjAppendElement(i,pX,Tcl_NewStringObj("UTF-16LE",-1));
+      break;
+    case SQLITE_UTF16BE:
+      Tcl_ListObjAppendElement(i,pX,Tcl_NewStringObj("UTF-16BE",-1));
+      break;
+    default:
+      assert(0);
+  }
+
+  pVal = sqlite3ValueNew(0);
+  sqlite3ValueSetStr(pVal, nA, zA, encin, SQLITE_STATIC);
+  n = sqlite3_value_bytes(pVal);
+  Tcl_ListObjAppendElement(i,pX,
+      Tcl_NewStringObj((char*)sqlite3_value_text(pVal),n));
+  sqlite3ValueSetStr(pVal, nB, zB, encin, SQLITE_STATIC);
+  n = sqlite3_value_bytes(pVal);
+  Tcl_ListObjAppendElement(i,pX,
+      Tcl_NewStringObj((char*)sqlite3_value_text(pVal),n));
+  sqlite3ValueFree(pVal);
+
+  Tcl_EvalObjEx(i, pX, 0);
+  Tcl_DecrRefCount(pX);
+  Tcl_GetIntFromObj(i, Tcl_GetObjResult(i), &res);
+  return res;
+}
+static int test_collate(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  int val;
+  sqlite3_value *pVal;
+  int rc;
+
+  if( objc!=5 ) goto bad_args;
+  pTestCollateInterp = interp;
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+
+  if( TCL_OK!=Tcl_GetBooleanFromObj(interp, objv[2], &val) ) return TCL_ERROR;
+  rc = sqlite3_create_collation(db, "test_collate", SQLITE_UTF8, 
+          (void *)SQLITE_UTF8, val?test_collate_func:0);
+  if( rc==SQLITE_OK ){
+    const void *zUtf16;
+    if( TCL_OK!=Tcl_GetBooleanFromObj(interp, objv[3], &val) ) return TCL_ERROR;
+    rc = sqlite3_create_collation(db, "test_collate", SQLITE_UTF16LE, 
+            (void *)SQLITE_UTF16LE, val?test_collate_func:0);
+    if( TCL_OK!=Tcl_GetBooleanFromObj(interp, objv[4], &val) ) return TCL_ERROR;
+
+#if 0
+    if( sqlite3_iMallocFail>0 ){
+      sqlite3_iMallocFail++;
+    }
+#endif
+    sqlite3_mutex_enter(db->mutex);
+    pVal = sqlite3ValueNew(db);
+    sqlite3ValueSetStr(pVal, -1, "test_collate", SQLITE_UTF8, SQLITE_STATIC);
+    zUtf16 = sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
+    if( db->mallocFailed ){
+      rc = SQLITE_NOMEM;
+    }else{
+      rc = sqlite3_create_collation16(db, zUtf16, SQLITE_UTF16BE, 
+          (void *)SQLITE_UTF16BE, val?test_collate_func:0);
+    }
+    sqlite3ValueFree(pVal);
+    sqlite3_mutex_leave(db->mutex);
+  }
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, sqlite3TestErrorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+
+bad_args:
+  Tcl_AppendResult(interp, "wrong # args: should be \"",
+      Tcl_GetStringFromObj(objv[0], 0), " <DB> <utf8> <utf16le> <utf16be>", 0);
+  return TCL_ERROR;
+}
+
+/*
+** When the collation needed callback is invoked, record the name of 
+** the requested collating function here.  The recorded name is linked
+** to a TCL variable and used to make sure that the requested collation
+** name is correct.
+*/
+static char zNeededCollation[200];
+static char *pzNeededCollation = zNeededCollation;
+
+
+/*
+** Called when a collating sequence is needed.  Registered using
+** sqlite3_collation_needed16().
+*/
+static void test_collate_needed_cb(
+  void *pCtx, 
+  sqlite3 *db,
+  int eTextRep,
+  const void *pName
+){
+  int enc = ENC(db);
+  int i;
+  char *z;
+  for(z = (char*)pName, i=0; *z || z[1]; z++){
+    if( *z ) zNeededCollation[i++] = *z;
+  }
+  zNeededCollation[i] = 0;
+  sqlite3_create_collation(
+      db, "test_collate", ENC(db), (void *)enc, test_collate_func);
+}
+
+/*
+** Usage: add_test_collate_needed DB
+*/
+static int test_collate_needed(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  int rc;
+
+  if( objc!=2 ) goto bad_args;
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  rc = sqlite3_collation_needed16(db, 0, test_collate_needed_cb);
+  zNeededCollation[0] = 0;
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  return TCL_OK;
+
+bad_args:
+  Tcl_WrongNumArgs(interp, 1, objv, "DB");
+  return TCL_ERROR;
+}
+
+/*
+** tclcmd:   add_alignment_test_collations  DB
+**
+** Add two new collating sequences to the database DB
+**
+**     utf16_aligned
+**     utf16_unaligned
+**
+** Both collating sequences use the same sort order as BINARY.
+** The only difference is that the utf16_aligned collating
+** sequence is declared with the SQLITE_UTF16_ALIGNED flag.
+** Both collating functions increment the unaligned utf16 counter
+** whenever they see a string that begins on an odd byte boundary.
+*/
+static int unaligned_string_counter = 0;
+static int alignmentCollFunc(
+  void *NotUsed,
+  int nKey1, const void *pKey1,
+  int nKey2, const void *pKey2
+){
+  int rc, n;
+  n = nKey1<nKey2 ? nKey1 : nKey2;
+  if( nKey1>0 && 1==(1&(int)pKey1) ) unaligned_string_counter++;
+  if( nKey2>0 && 1==(1&(int)pKey2) ) unaligned_string_counter++;
+  rc = memcmp(pKey1, pKey2, n);
+  if( rc==0 ){
+    rc = nKey1 - nKey2;
+  }
+  return rc;
+}
+static int add_alignment_test_collations(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  if( objc>=2 ){
+    if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+    sqlite3_create_collation(db, "utf16_unaligned",
+        SQLITE_UTF16, 
+        0, alignmentCollFunc);
+    sqlite3_create_collation(db, "utf16_aligned",
+        SQLITE_UTF16 | SQLITE_UTF16_ALIGNED, 
+        0, alignmentCollFunc);
+  }
+  return SQLITE_OK;
+}
+#endif /* !defined(SQLITE_OMIT_UTF16) */
+
+/*
+** Usage: add_test_function <db ptr> <utf8> <utf16le> <utf16be>
+**
+** This function is used to test that SQLite selects the correct user
+** function callback when multiple versions (for different text encodings)
+** are available.
+**
+** Calling this routine registers up to three versions of the user function
+** "test_function" with database handle <db>.  If the second argument is
+** true, then a version of test_function is registered for UTF-8, if the
+** third is true, a version is registered for UTF-16le, if the fourth is
+** true, a UTF-16be version is available.  Previous versions of
+** test_function are deleted.
+**
+** The user function is implemented by calling the following TCL script:
+**
+**   "test_function <enc> <arg>"
+**
+** Where <enc> is one of UTF-8, UTF-16LE or UTF16BE, and <arg> is the
+** single argument passed to the SQL function. The value returned by
+** the TCL script is used as the return value of the SQL function. It
+** is passed to SQLite using UTF-16BE for a UTF-8 test_function(), UTF-8
+** for a UTF-16LE test_function(), and UTF-16LE for an implementation that
+** prefers UTF-16BE.
+*/
+#ifndef SQLITE_OMIT_UTF16
+static void test_function_utf8(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  Tcl_Interp *interp;
+  Tcl_Obj *pX;
+  sqlite3_value *pVal;
+  interp = (Tcl_Interp *)sqlite3_user_data(pCtx);
+  pX = Tcl_NewStringObj("test_function", -1);
+  Tcl_IncrRefCount(pX);
+  Tcl_ListObjAppendElement(interp, pX, Tcl_NewStringObj("UTF-8", -1));
+  Tcl_ListObjAppendElement(interp, pX, 
+      Tcl_NewStringObj((char*)sqlite3_value_text(argv[0]), -1));
+  Tcl_EvalObjEx(interp, pX, 0);
+  Tcl_DecrRefCount(pX);
+  sqlite3_result_text(pCtx, Tcl_GetStringResult(interp), -1, SQLITE_TRANSIENT);
+  pVal = sqlite3ValueNew(0);
+  sqlite3ValueSetStr(pVal, -1, Tcl_GetStringResult(interp), 
+      SQLITE_UTF8, SQLITE_STATIC);
+  sqlite3_result_text16be(pCtx, sqlite3_value_text16be(pVal),
+      -1, SQLITE_TRANSIENT);
+  sqlite3ValueFree(pVal);
+}
+static void test_function_utf16le(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  Tcl_Interp *interp;
+  Tcl_Obj *pX;
+  sqlite3_value *pVal;
+  interp = (Tcl_Interp *)sqlite3_user_data(pCtx);
+  pX = Tcl_NewStringObj("test_function", -1);
+  Tcl_IncrRefCount(pX);
+  Tcl_ListObjAppendElement(interp, pX, Tcl_NewStringObj("UTF-16LE", -1));
+  Tcl_ListObjAppendElement(interp, pX, 
+      Tcl_NewStringObj((char*)sqlite3_value_text(argv[0]), -1));
+  Tcl_EvalObjEx(interp, pX, 0);
+  Tcl_DecrRefCount(pX);
+  pVal = sqlite3ValueNew(0);
+  sqlite3ValueSetStr(pVal, -1, Tcl_GetStringResult(interp), 
+      SQLITE_UTF8, SQLITE_STATIC);
+  sqlite3_result_text(pCtx,(char*)sqlite3_value_text(pVal),-1,SQLITE_TRANSIENT);
+  sqlite3ValueFree(pVal);
+}
+static void test_function_utf16be(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  Tcl_Interp *interp;
+  Tcl_Obj *pX;
+  sqlite3_value *pVal;
+  interp = (Tcl_Interp *)sqlite3_user_data(pCtx);
+  pX = Tcl_NewStringObj("test_function", -1);
+  Tcl_IncrRefCount(pX);
+  Tcl_ListObjAppendElement(interp, pX, Tcl_NewStringObj("UTF-16BE", -1));
+  Tcl_ListObjAppendElement(interp, pX, 
+      Tcl_NewStringObj((char*)sqlite3_value_text(argv[0]), -1));
+  Tcl_EvalObjEx(interp, pX, 0);
+  Tcl_DecrRefCount(pX);
+  pVal = sqlite3ValueNew(0);
+  sqlite3ValueSetStr(pVal, -1, Tcl_GetStringResult(interp), 
+      SQLITE_UTF8, SQLITE_STATIC);
+  sqlite3_result_text16(pCtx, sqlite3_value_text16le(pVal),
+      -1, SQLITE_TRANSIENT);
+  sqlite3_result_text16be(pCtx, sqlite3_value_text16le(pVal),
+      -1, SQLITE_TRANSIENT);
+  sqlite3_result_text16le(pCtx, sqlite3_value_text16le(pVal),
+      -1, SQLITE_TRANSIENT);
+  sqlite3ValueFree(pVal);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+static int test_function(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifndef SQLITE_OMIT_UTF16
+  sqlite3 *db;
+  int val;
+
+  if( objc!=5 ) goto bad_args;
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+
+  if( TCL_OK!=Tcl_GetBooleanFromObj(interp, objv[2], &val) ) return TCL_ERROR;
+  if( val ){
+    sqlite3_create_function(db, "test_function", 1, SQLITE_UTF8, 
+        interp, test_function_utf8, 0, 0);
+  }
+  if( TCL_OK!=Tcl_GetBooleanFromObj(interp, objv[3], &val) ) return TCL_ERROR;
+  if( val ){
+    sqlite3_create_function(db, "test_function", 1, SQLITE_UTF16LE, 
+        interp, test_function_utf16le, 0, 0);
+  }
+  if( TCL_OK!=Tcl_GetBooleanFromObj(interp, objv[4], &val) ) return TCL_ERROR;
+  if( val ){
+    sqlite3_create_function(db, "test_function", 1, SQLITE_UTF16BE, 
+        interp, test_function_utf16be, 0, 0);
+  }
+
+  return TCL_OK;
+bad_args:
+  Tcl_AppendResult(interp, "wrong # args: should be \"",
+      Tcl_GetStringFromObj(objv[0], 0), " <DB> <utf8> <utf16le> <utf16be>", 0);
+#endif /* SQLITE_OMIT_UTF16 */
+  return TCL_ERROR;
+}
+
+/*
+** Usage:         test_errstr <err code>
+**
+** Test that the english language string equivalents for sqlite error codes
+** are sane. The parameter is an integer representing an sqlite error code.
+** The result is a list of two elements, the string representation of the
+** error code and the english language explanation.
+*/
+static int test_errstr(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  char *zCode;
+  int i;
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "<error code>");
+  }
+
+  zCode = Tcl_GetString(objv[1]);
+  for(i=0; i<200; i++){
+    if( 0==strcmp(t1ErrorName(i), zCode) ) break;
+  }
+  Tcl_SetResult(interp, (char *)sqlite3ErrStr(i), 0);
+  return TCL_OK;
+}
+
+/*
+** Usage:    breakpoint
+**
+** This routine exists for one purpose - to provide a place to put a
+** breakpoint with GDB that can be triggered using TCL code.  The use
+** for this is when a particular test fails on (say) the 1485th iteration.
+** In the TCL test script, we can add code like this:
+**
+**     if {$i==1485} breakpoint
+**
+** Then run testfixture in the debugger and wait for the breakpoint to
+** fire.  Then additional breakpoints can be set to trace down the bug.
+*/
+static int test_breakpoint(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  return TCL_OK;         /* Do nothing */
+}
+
+/*
+** Usage:   sqlite3_bind_zeroblob  STMT IDX N
+**
+** Test the sqlite3_bind_zeroblob interface.  STMT is a prepared statement.
+** IDX is the index of a wildcard in the prepared statement.  This command
+** binds a N-byte zero-filled BLOB to the wildcard.
+*/
+static int test_bind_zeroblob(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int idx;
+  int n;
+  int rc;
+
+  if( objc!=4 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "STMT IDX N");
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &idx) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[3], &n) ) return TCL_ERROR;
+
+  rc = sqlite3_bind_zeroblob(pStmt, idx, n);
+  if( sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ) return TCL_ERROR;
+  if( rc!=SQLITE_OK ){
+    return TCL_ERROR;
+  }
+
+  return TCL_OK;
+}
+
+/*
+** Usage:   sqlite3_bind_int  STMT N VALUE
+**
+** Test the sqlite3_bind_int interface.  STMT is a prepared statement.
+** N is the index of a wildcard in the prepared statement.  This command
+** binds a 32-bit integer VALUE to that wildcard.
+*/
+static int test_bind_int(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int idx;
+  int value;
+  int rc;
+
+  if( objc!=4 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " STMT N VALUE", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &idx) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[3], &value) ) return TCL_ERROR;
+
+  rc = sqlite3_bind_int(pStmt, idx, value);
+  if( sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ) return TCL_ERROR;
+  if( rc!=SQLITE_OK ){
+    return TCL_ERROR;
+  }
+
+  return TCL_OK;
+}
+
+
+/*
+** Usage:   sqlite3_bind_int64  STMT N VALUE
+**
+** Test the sqlite3_bind_int64 interface.  STMT is a prepared statement.
+** N is the index of a wildcard in the prepared statement.  This command
+** binds a 64-bit integer VALUE to that wildcard.
+*/
+static int test_bind_int64(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int idx;
+  i64 value;
+  int rc;
+
+  if( objc!=4 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " STMT N VALUE", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &idx) ) return TCL_ERROR;
+  if( Tcl_GetWideIntFromObj(interp, objv[3], &value) ) return TCL_ERROR;
+
+  rc = sqlite3_bind_int64(pStmt, idx, value);
+  if( sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ) return TCL_ERROR;
+  if( rc!=SQLITE_OK ){
+    return TCL_ERROR;
+  }
+
+  return TCL_OK;
+}
+
+
+/*
+** Usage:   sqlite3_bind_double  STMT N VALUE
+**
+** Test the sqlite3_bind_double interface.  STMT is a prepared statement.
+** N is the index of a wildcard in the prepared statement.  This command
+** binds a 64-bit integer VALUE to that wildcard.
+*/
+static int test_bind_double(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int idx;
+  double value;
+  int rc;
+  const char *zVal;
+  int i;
+  static const struct {
+    const char *zName;     /* Name of the special floating point value */
+    unsigned int iUpper;   /* Upper 32 bits */
+    unsigned int iLower;   /* Lower 32 bits */
+  } aSpecialFp[] = {
+    {  "NaN",      0x7fffffff, 0xffffffff },
+    {  "SNaN",     0x7ff7ffff, 0xffffffff },
+    {  "-NaN",     0xffffffff, 0xffffffff },
+    {  "-SNaN",    0xfff7ffff, 0xffffffff },
+    {  "+Inf",     0x7ff00000, 0x00000000 },
+    {  "-Inf",     0xfff00000, 0x00000000 },
+    {  "Epsilon",  0x00000000, 0x00000001 },
+    {  "-Epsilon", 0x80000000, 0x00000001 },
+    {  "NaN0",     0x7ff80000, 0x00000000 },
+    {  "-NaN0",    0xfff80000, 0x00000000 },
+  };
+
+  if( objc!=4 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " STMT N VALUE", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &idx) ) return TCL_ERROR;
+
+  /* Intercept the string "NaN" and generate a NaN value for it.
+  ** All other strings are passed through to Tcl_GetDoubleFromObj().
+  ** Tcl_GetDoubleFromObj() should understand "NaN" but some versions
+  ** contain a bug.
+  */
+  zVal = Tcl_GetString(objv[3]);
+  for(i=0; i<sizeof(aSpecialFp)/sizeof(aSpecialFp[0]); i++){
+    if( strcmp(aSpecialFp[i].zName, zVal)==0 ){
+      sqlite3_uint64 x;
+      x = aSpecialFp[i].iUpper;
+      x <<= 32;
+      x |= aSpecialFp[i].iLower;
+      assert( sizeof(value)==8 );
+      assert( sizeof(x)==8 );
+      memcpy(&value, &x, 8);
+      break;
+    }
+  }
+  if( i>=sizeof(aSpecialFp)/sizeof(aSpecialFp[0]) &&
+         Tcl_GetDoubleFromObj(interp, objv[3], &value) ){
+    return TCL_ERROR;
+  }
+  rc = sqlite3_bind_double(pStmt, idx, value);
+  if( sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ) return TCL_ERROR;
+  if( rc!=SQLITE_OK ){
+    return TCL_ERROR;
+  }
+
+  return TCL_OK;
+}
+
+/*
+** Usage:   sqlite3_bind_null  STMT N
+**
+** Test the sqlite3_bind_null interface.  STMT is a prepared statement.
+** N is the index of a wildcard in the prepared statement.  This command
+** binds a NULL to the wildcard.
+*/
+static int test_bind_null(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int idx;
+  int rc;
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " STMT N", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &idx) ) return TCL_ERROR;
+
+  rc = sqlite3_bind_null(pStmt, idx);
+  if( sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ) return TCL_ERROR;
+  if( rc!=SQLITE_OK ){
+    return TCL_ERROR;
+  }
+
+  return TCL_OK;
+}
+
+/*
+** Usage:   sqlite3_bind_text  STMT N STRING BYTES
+**
+** Test the sqlite3_bind_text interface.  STMT is a prepared statement.
+** N is the index of a wildcard in the prepared statement.  This command
+** binds a UTF-8 string STRING to the wildcard.  The string is BYTES bytes
+** long.
+*/
+static int test_bind_text(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int idx;
+  int bytes;
+  char *value;
+  int rc;
+
+  if( objc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " STMT N VALUE BYTES", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &idx) ) return TCL_ERROR;
+  value = (char*)Tcl_GetByteArrayFromObj(objv[3], &bytes);
+  if( Tcl_GetIntFromObj(interp, objv[4], &bytes) ) return TCL_ERROR;
+
+  rc = sqlite3_bind_text(pStmt, idx, value, bytes, SQLITE_TRANSIENT);
+  if( sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ) return TCL_ERROR;
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, sqlite3TestErrorName(rc), 0);
+    return TCL_ERROR;
+  }
+
+  return TCL_OK;
+}
+
+/*
+** Usage:   sqlite3_bind_text16 ?-static? STMT N STRING BYTES
+**
+** Test the sqlite3_bind_text16 interface.  STMT is a prepared statement.
+** N is the index of a wildcard in the prepared statement.  This command
+** binds a UTF-16 string STRING to the wildcard.  The string is BYTES bytes
+** long.
+*/
+static int test_bind_text16(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifndef SQLITE_OMIT_UTF16
+  sqlite3_stmt *pStmt;
+  int idx;
+  int bytes;
+  char *value;
+  int rc;
+
+  void (*xDel)() = (objc==6?SQLITE_STATIC:SQLITE_TRANSIENT);
+  Tcl_Obj *oStmt    = objv[objc-4];
+  Tcl_Obj *oN       = objv[objc-3];
+  Tcl_Obj *oString  = objv[objc-2];
+  Tcl_Obj *oBytes   = objv[objc-1];
+
+  if( objc!=5 && objc!=6){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " STMT N VALUE BYTES", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(oStmt), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, oN, &idx) ) return TCL_ERROR;
+  value = (char*)Tcl_GetByteArrayFromObj(oString, 0);
+  if( Tcl_GetIntFromObj(interp, oBytes, &bytes) ) return TCL_ERROR;
+
+  rc = sqlite3_bind_text16(pStmt, idx, (void *)value, bytes, xDel);
+  if( sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ) return TCL_ERROR;
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, sqlite3TestErrorName(rc), 0);
+    return TCL_ERROR;
+  }
+
+#endif /* SQLITE_OMIT_UTF16 */
+  return TCL_OK;
+}
+
+/*
+** Usage:   sqlite3_bind_blob ?-static? STMT N DATA BYTES
+**
+** Test the sqlite3_bind_blob interface.  STMT is a prepared statement.
+** N is the index of a wildcard in the prepared statement.  This command
+** binds a BLOB to the wildcard.  The BLOB is BYTES bytes in size.
+*/
+static int test_bind_blob(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int idx;
+  int bytes;
+  char *value;
+  int rc;
+  sqlite3_destructor_type xDestructor = SQLITE_TRANSIENT;
+
+  if( objc!=5 && objc!=6 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " STMT N DATA BYTES", 0);
+    return TCL_ERROR;
+  }
+
+  if( objc==6 ){
+    xDestructor = SQLITE_STATIC;
+    objv++;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &idx) ) return TCL_ERROR;
+  value = Tcl_GetString(objv[3]);
+  if( Tcl_GetIntFromObj(interp, objv[4], &bytes) ) return TCL_ERROR;
+
+  rc = sqlite3_bind_blob(pStmt, idx, value, bytes, xDestructor);
+  if( sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ) return TCL_ERROR;
+  if( rc!=SQLITE_OK ){
+    return TCL_ERROR;
+  }
+
+  return TCL_OK;
+}
+
+/*
+** Usage:   sqlite3_bind_parameter_count  STMT
+**
+** Return the number of wildcards in the given statement.
+*/
+static int test_bind_parameter_count(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "STMT");
+    return TCL_ERROR;
+  }
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(sqlite3_bind_parameter_count(pStmt)));
+  return TCL_OK;
+}
+
+/*
+** Usage:   sqlite3_bind_parameter_name  STMT  N
+**
+** Return the name of the Nth wildcard.  The first wildcard is 1.
+** An empty string is returned if N is out of range or if the wildcard
+** is nameless.
+*/
+static int test_bind_parameter_name(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int i;
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "STMT N");
+    return TCL_ERROR;
+  }
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &i) ) return TCL_ERROR;
+  Tcl_SetObjResult(interp, 
+     Tcl_NewStringObj(sqlite3_bind_parameter_name(pStmt,i),-1)
+  );
+  return TCL_OK;
+}
+
+/*
+** Usage:   sqlite3_bind_parameter_index  STMT  NAME
+**
+** Return the index of the wildcard called NAME.  Return 0 if there is
+** no such wildcard.
+*/
+static int test_bind_parameter_index(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "STMT NAME");
+    return TCL_ERROR;
+  }
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  Tcl_SetObjResult(interp, 
+     Tcl_NewIntObj(
+       sqlite3_bind_parameter_index(pStmt,Tcl_GetString(objv[2]))
+     )
+  );
+  return TCL_OK;
+}
+
+/*
+** Usage:   sqlite3_clear_bindings STMT
+**
+*/
+static int test_clear_bindings(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "STMT");
+    return TCL_ERROR;
+  }
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(sqlite3_clear_bindings(pStmt)));
+  return TCL_OK;
+}
+
+/*
+** Usage:   sqlite3_sleep MILLISECONDS
+*/
+static int test_sleep(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int ms;
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "MILLISECONDS");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[1], &ms) ){
+    return TCL_ERROR;
+  }
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(sqlite3_sleep(ms)));
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_errcode DB
+**
+** Return the string representation of the most recent sqlite3_* API
+** error code. e.g. "SQLITE_ERROR".
+*/
+static int test_errcode(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  int rc;
+  char zBuf[30];
+
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " DB", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  rc = sqlite3_errcode(db);
+  if( (rc&0xff)==rc ){
+    zBuf[0] = 0;
+  }else{
+    sprintf(zBuf,"+%d", rc>>8);
+  }
+  Tcl_AppendResult(interp, (char *)t1ErrorName(rc), zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage:   test_errmsg DB
+**
+** Returns the UTF-8 representation of the error message string for the
+** most recent sqlite3_* API call.
+*/
+static int test_errmsg(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  const char *zErr;
+
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " DB", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+
+  zErr = sqlite3_errmsg(db);
+  Tcl_SetObjResult(interp, Tcl_NewStringObj(zErr, -1));
+  return TCL_OK;
+}
+
+/*
+** Usage:   test_errmsg16 DB
+**
+** Returns the UTF-16 representation of the error message string for the
+** most recent sqlite3_* API call. This is a byte array object at the TCL 
+** level, and it includes the 0x00 0x00 terminator bytes at the end of the
+** UTF-16 string.
+*/
+static int test_errmsg16(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifndef SQLITE_OMIT_UTF16
+  sqlite3 *db;
+  const void *zErr;
+  int bytes = 0;
+
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " DB", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+
+  zErr = sqlite3_errmsg16(db);
+  if( zErr ){
+    bytes = sqlite3Utf16ByteLen(zErr, -1);
+  }
+  Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(zErr, bytes));
+#endif /* SQLITE_OMIT_UTF16 */
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_prepare DB sql bytes tailvar
+**
+** Compile up to <bytes> bytes of the supplied SQL string <sql> using
+** database handle <DB>. The parameter <tailval> is the name of a global
+** variable that is set to the unused portion of <sql> (if any). A
+** STMT handle is returned.
+*/
+static int test_prepare(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  const char *zSql;
+  int bytes;
+  const char *zTail = 0;
+  sqlite3_stmt *pStmt = 0;
+  char zBuf[50];
+  int rc;
+
+  if( objc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " DB sql bytes tailvar", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  zSql = Tcl_GetString(objv[2]);
+  if( Tcl_GetIntFromObj(interp, objv[3], &bytes) ) return TCL_ERROR;
+
+  rc = sqlite3_prepare(db, zSql, bytes, &pStmt, &zTail);
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  if( zTail ){
+    if( bytes>=0 ){
+      bytes = bytes - (zTail-zSql);
+    }
+    if( strlen(zTail)<bytes ){
+      bytes = strlen(zTail);
+    }
+    Tcl_ObjSetVar2(interp, objv[4], 0, Tcl_NewStringObj(zTail, bytes), 0);
+  }
+  if( rc!=SQLITE_OK ){
+    assert( pStmt==0 );
+    sprintf(zBuf, "(%d) ", rc);
+    Tcl_AppendResult(interp, zBuf, sqlite3_errmsg(db), 0);
+    return TCL_ERROR;
+  }
+
+  if( pStmt ){
+    if( sqlite3TestMakePointerStr(interp, zBuf, pStmt) ) return TCL_ERROR;
+    Tcl_AppendResult(interp, zBuf, 0);
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_prepare_v2 DB sql bytes tailvar
+**
+** Compile up to <bytes> bytes of the supplied SQL string <sql> using
+** database handle <DB>. The parameter <tailval> is the name of a global
+** variable that is set to the unused portion of <sql> (if any). A
+** STMT handle is returned.
+*/
+static int test_prepare_v2(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  const char *zSql;
+  int bytes;
+  const char *zTail = 0;
+  sqlite3_stmt *pStmt = 0;
+  char zBuf[50];
+  int rc;
+
+  if( objc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " DB sql bytes tailvar", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  zSql = Tcl_GetString(objv[2]);
+  if( Tcl_GetIntFromObj(interp, objv[3], &bytes) ) return TCL_ERROR;
+
+  rc = sqlite3_prepare_v2(db, zSql, bytes, &pStmt, &zTail);
+  assert(rc==SQLITE_OK || pStmt==0);
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  if( zTail ){
+    if( bytes>=0 ){
+      bytes = bytes - (zTail-zSql);
+    }
+    Tcl_ObjSetVar2(interp, objv[4], 0, Tcl_NewStringObj(zTail, bytes), 0);
+  }
+  if( rc!=SQLITE_OK ){
+    assert( pStmt==0 );
+    sprintf(zBuf, "(%d) ", rc);
+    Tcl_AppendResult(interp, zBuf, sqlite3_errmsg(db), 0);
+    return TCL_ERROR;
+  }
+
+  if( pStmt ){
+    if( sqlite3TestMakePointerStr(interp, zBuf, pStmt) ) return TCL_ERROR;
+    Tcl_AppendResult(interp, zBuf, 0);
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_prepare_tkt3134 DB
+**
+** Generate a prepared statement for a zero-byte string as a test
+** for ticket #3134.  The string should be preceeded by a zero byte.
+*/
+static int test_prepare_tkt3134(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  static const char zSql[] = "\000SELECT 1";
+  sqlite3_stmt *pStmt = 0;
+  char zBuf[50];
+  int rc;
+
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " DB sql bytes tailvar", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  rc = sqlite3_prepare_v2(db, &zSql[1], 0, &pStmt, 0);
+  assert(rc==SQLITE_OK || pStmt==0);
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  if( rc!=SQLITE_OK ){
+    assert( pStmt==0 );
+    sprintf(zBuf, "(%d) ", rc);
+    Tcl_AppendResult(interp, zBuf, sqlite3_errmsg(db), 0);
+    return TCL_ERROR;
+  }
+
+  if( pStmt ){
+    if( sqlite3TestMakePointerStr(interp, zBuf, pStmt) ) return TCL_ERROR;
+    Tcl_AppendResult(interp, zBuf, 0);
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_prepare16 DB sql bytes tailvar
+**
+** Compile up to <bytes> bytes of the supplied SQL string <sql> using
+** database handle <DB>. The parameter <tailval> is the name of a global
+** variable that is set to the unused portion of <sql> (if any). A
+** STMT handle is returned.
+*/
+static int test_prepare16(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifndef SQLITE_OMIT_UTF16
+  sqlite3 *db;
+  const void *zSql;
+  const void *zTail = 0;
+  Tcl_Obj *pTail = 0;
+  sqlite3_stmt *pStmt = 0;
+  char zBuf[50]; 
+  int rc;
+  int bytes;                /* The integer specified as arg 3 */
+  int objlen;               /* The byte-array length of arg 2 */
+
+  if( objc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " DB sql bytes tailvar", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  zSql = Tcl_GetByteArrayFromObj(objv[2], &objlen);
+  if( Tcl_GetIntFromObj(interp, objv[3], &bytes) ) return TCL_ERROR;
+
+  rc = sqlite3_prepare16(db, zSql, bytes, &pStmt, &zTail);
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  if( rc ){
+    return TCL_ERROR;
+  }
+
+  if( zTail ){
+    objlen = objlen - ((u8 *)zTail-(u8 *)zSql);
+  }else{
+    objlen = 0;
+  }
+  pTail = Tcl_NewByteArrayObj((u8 *)zTail, objlen);
+  Tcl_IncrRefCount(pTail);
+  Tcl_ObjSetVar2(interp, objv[4], 0, pTail, 0);
+  Tcl_DecrRefCount(pTail);
+
+  if( pStmt ){
+    if( sqlite3TestMakePointerStr(interp, zBuf, pStmt) ) return TCL_ERROR;
+  }
+  Tcl_AppendResult(interp, zBuf, 0);
+#endif /* SQLITE_OMIT_UTF16 */
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_prepare16_v2 DB sql bytes tailvar
+**
+** Compile up to <bytes> bytes of the supplied SQL string <sql> using
+** database handle <DB>. The parameter <tailval> is the name of a global
+** variable that is set to the unused portion of <sql> (if any). A
+** STMT handle is returned.
+*/
+static int test_prepare16_v2(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifndef SQLITE_OMIT_UTF16
+  sqlite3 *db;
+  const void *zSql;
+  const void *zTail = 0;
+  Tcl_Obj *pTail = 0;
+  sqlite3_stmt *pStmt = 0;
+  char zBuf[50]; 
+  int rc;
+  int bytes;                /* The integer specified as arg 3 */
+  int objlen;               /* The byte-array length of arg 2 */
+
+  if( objc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " DB sql bytes tailvar", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  zSql = Tcl_GetByteArrayFromObj(objv[2], &objlen);
+  if( Tcl_GetIntFromObj(interp, objv[3], &bytes) ) return TCL_ERROR;
+
+  rc = sqlite3_prepare16_v2(db, zSql, bytes, &pStmt, &zTail);
+  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
+  if( rc ){
+    return TCL_ERROR;
+  }
+
+  if( zTail ){
+    objlen = objlen - ((u8 *)zTail-(u8 *)zSql);
+  }else{
+    objlen = 0;
+  }
+  pTail = Tcl_NewByteArrayObj((u8 *)zTail, objlen);
+  Tcl_IncrRefCount(pTail);
+  Tcl_ObjSetVar2(interp, objv[4], 0, pTail, 0);
+  Tcl_DecrRefCount(pTail);
+
+  if( pStmt ){
+    if( sqlite3TestMakePointerStr(interp, zBuf, pStmt) ) return TCL_ERROR;
+  }
+  Tcl_AppendResult(interp, zBuf, 0);
+#endif /* SQLITE_OMIT_UTF16 */
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_open filename ?options-list?
+*/
+static int test_open(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  const char *zFilename;
+  sqlite3 *db;
+  int rc;
+  char zBuf[100];
+
+  if( objc!=3 && objc!=2 && objc!=1 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " filename options-list", 0);
+    return TCL_ERROR;
+  }
+
+  zFilename = objc>1 ? Tcl_GetString(objv[1]) : 0;
+  rc = sqlite3_open(zFilename, &db);
+  
+  if( sqlite3TestMakePointerStr(interp, zBuf, db) ) return TCL_ERROR;
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_open16 filename options
+*/
+static int test_open16(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifndef SQLITE_OMIT_UTF16
+  const void *zFilename;
+  sqlite3 *db;
+  int rc;
+  char zBuf[100];
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " filename options-list", 0);
+    return TCL_ERROR;
+  }
+
+  zFilename = Tcl_GetByteArrayFromObj(objv[1], 0);
+  rc = sqlite3_open16(zFilename, &db);
+  
+  if( sqlite3TestMakePointerStr(interp, zBuf, db) ) return TCL_ERROR;
+  Tcl_AppendResult(interp, zBuf, 0);
+#endif /* SQLITE_OMIT_UTF16 */
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_complete16 <UTF-16 string>
+**
+** Return 1 if the supplied argument is a complete SQL statement, or zero
+** otherwise.
+*/
+static int test_complete16(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#if !defined(SQLITE_OMIT_COMPLETE) && !defined(SQLITE_OMIT_UTF16)
+  char *zBuf;
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "<utf-16 sql>");
+    return TCL_ERROR;
+  }
+
+  zBuf = (char*)Tcl_GetByteArrayFromObj(objv[1], 0);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(sqlite3_complete16(zBuf)));
+#endif /* SQLITE_OMIT_COMPLETE && SQLITE_OMIT_UTF16 */
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_step STMT
+**
+** Advance the statement to the next row.
+*/
+static int test_step(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int rc;
+
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " STMT", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  rc = sqlite3_step(pStmt);
+
+  /* if( rc!=SQLITE_DONE && rc!=SQLITE_ROW ) return TCL_ERROR; */
+  Tcl_SetResult(interp, (char *)t1ErrorName(rc), 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_column_count STMT 
+**
+** Return the number of columns returned by the sql statement STMT.
+*/
+static int test_column_count(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " STMT column", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(sqlite3_column_count(pStmt)));
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_column_type STMT column
+**
+** Return the type of the data in column 'column' of the current row.
+*/
+static int test_column_type(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int col;
+  int tp;
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " STMT column", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &col) ) return TCL_ERROR;
+
+  tp = sqlite3_column_type(pStmt, col);
+  switch( tp ){
+    case SQLITE_INTEGER: 
+      Tcl_SetResult(interp, "INTEGER", TCL_STATIC); 
+      break;
+    case SQLITE_NULL:
+      Tcl_SetResult(interp, "NULL", TCL_STATIC); 
+      break;
+    case SQLITE_FLOAT:
+      Tcl_SetResult(interp, "FLOAT", TCL_STATIC); 
+      break;
+    case SQLITE_TEXT:
+      Tcl_SetResult(interp, "TEXT", TCL_STATIC); 
+      break;
+    case SQLITE_BLOB:
+      Tcl_SetResult(interp, "BLOB", TCL_STATIC); 
+      break;
+    default:
+      assert(0);
+  }
+
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_column_int64 STMT column
+**
+** Return the data in column 'column' of the current row cast as an
+** wide (64-bit) integer.
+*/
+static int test_column_int64(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int col;
+  i64 iVal;
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " STMT column", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &col) ) return TCL_ERROR;
+
+  iVal = sqlite3_column_int64(pStmt, col);
+  Tcl_SetObjResult(interp, Tcl_NewWideIntObj(iVal));
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_column_blob STMT column
+*/
+static int test_column_blob(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int col;
+
+  int len;
+  const void *pBlob;
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " STMT column", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &col) ) return TCL_ERROR;
+
+  len = sqlite3_column_bytes(pStmt, col);
+  pBlob = sqlite3_column_blob(pStmt, col);
+  Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(pBlob, len));
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_column_double STMT column
+**
+** Return the data in column 'column' of the current row cast as a double.
+*/
+static int test_column_double(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int col;
+  double rVal;
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " STMT column", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &col) ) return TCL_ERROR;
+
+  rVal = sqlite3_column_double(pStmt, col);
+  Tcl_SetObjResult(interp, Tcl_NewDoubleObj(rVal));
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_data_count STMT 
+**
+** Return the number of columns returned by the sql statement STMT.
+*/
+static int test_data_count(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " STMT column", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(sqlite3_data_count(pStmt)));
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_column_text STMT column
+**
+** Usage: sqlite3_column_decltype STMT column
+**
+** Usage: sqlite3_column_name STMT column
+*/
+static int test_stmt_utf8(
+  void * clientData,        /* Pointer to SQLite API function to be invoke */
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int col;
+  const char *(*xFunc)(sqlite3_stmt*, int) = clientData;
+  const char *zRet;
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " STMT column", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &col) ) return TCL_ERROR;
+  zRet = xFunc(pStmt, col);
+  if( zRet ){
+    Tcl_SetResult(interp, (char *)zRet, 0);
+  }
+  return TCL_OK;
+}
+
+static int test_global_recover(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifndef SQLITE_OMIT_GLOBALRECOVER
+  int rc;
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+  rc = sqlite3_global_recover();
+  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
+#endif
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_column_text STMT column
+**
+** Usage: sqlite3_column_decltype STMT column
+**
+** Usage: sqlite3_column_name STMT column
+*/
+static int test_stmt_utf16(
+  void * clientData,     /* Pointer to SQLite API function to be invoked */
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifndef SQLITE_OMIT_UTF16
+  sqlite3_stmt *pStmt;
+  int col;
+  Tcl_Obj *pRet;
+  const void *zName16;
+  const void *(*xFunc)(sqlite3_stmt*, int) = clientData;
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " STMT column", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &col) ) return TCL_ERROR;
+
+  zName16 = xFunc(pStmt, col);
+  if( zName16 ){
+    pRet = Tcl_NewByteArrayObj(zName16, sqlite3Utf16ByteLen(zName16, -1)+2);
+    Tcl_SetObjResult(interp, pRet);
+  }
+#endif /* SQLITE_OMIT_UTF16 */
+
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_column_int STMT column
+**
+** Usage: sqlite3_column_bytes STMT column
+**
+** Usage: sqlite3_column_bytes16 STMT column
+**
+*/
+static int test_stmt_int(
+  void * clientData,    /* Pointer to SQLite API function to be invoked */
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int col;
+  int (*xFunc)(sqlite3_stmt*, int) = clientData;
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " STMT column", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &col) ) return TCL_ERROR;
+
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(xFunc(pStmt, col)));
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite_set_magic  DB  MAGIC-NUMBER
+**
+** Set the db->magic value.  This is used to test error recovery logic.
+*/
+static int sqlite_set_magic(
+  void * clientData,
+  Tcl_Interp *interp,
+  int argc,
+  char **argv
+){
+  sqlite3 *db;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+         " DB MAGIC", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  if( strcmp(argv[2], "SQLITE_MAGIC_OPEN")==0 ){
+    db->magic = SQLITE_MAGIC_OPEN;
+  }else if( strcmp(argv[2], "SQLITE_MAGIC_CLOSED")==0 ){
+    db->magic = SQLITE_MAGIC_CLOSED;
+  }else if( strcmp(argv[2], "SQLITE_MAGIC_BUSY")==0 ){
+    db->magic = SQLITE_MAGIC_BUSY;
+  }else if( strcmp(argv[2], "SQLITE_MAGIC_ERROR")==0 ){
+    db->magic = SQLITE_MAGIC_ERROR;
+  }else if( Tcl_GetInt(interp, argv[2], &db->magic) ){
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_interrupt  DB 
+**
+** Trigger an interrupt on DB
+*/
+static int test_interrupt(
+  void * clientData,
+  Tcl_Interp *interp,
+  int argc,
+  char **argv
+){
+  sqlite3 *db;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], " DB", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  sqlite3_interrupt(db);
+  return TCL_OK;
+}
+
+static u8 *sqlite3_stack_baseline = 0;
+
+/*
+** Fill the stack with a known bitpattern.
+*/
+static void prepStack(void){
+  int i;
+  u32 bigBuf[65536];
+  for(i=0; i<sizeof(bigBuf); i++) bigBuf[i] = 0xdeadbeef;
+  sqlite3_stack_baseline = (u8*)&bigBuf[65536];
+}
+
+/*
+** Get the current stack depth.  Used for debugging only.
+*/
+u64 sqlite3StackDepth(void){
+  u8 x;
+  return (u64)(sqlite3_stack_baseline - &x);
+}
+
+/*
+** Usage:  sqlite3_stack_used DB SQL
+**
+** Try to measure the amount of stack space used by a call to sqlite3_exec
+*/
+static int test_stack_used(
+  void * clientData,
+  Tcl_Interp *interp,
+  int argc,
+  char **argv
+){
+  sqlite3 *db;
+  int i;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+        " DB SQL", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  prepStack();
+  (void)sqlite3_exec(db, argv[2], 0, 0, 0);
+  for(i=65535; i>=0 && ((u32*)sqlite3_stack_baseline)[-i]==0xdeadbeef; i--){}
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(i*4));
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite_delete_function DB function-name
+**
+** Delete the user function 'function-name' from database handle DB. It
+** is assumed that the user function was created as UTF8, any number of
+** arguments (the way the TCL interface does it).
+*/
+static int delete_function(
+  void * clientData,
+  Tcl_Interp *interp,
+  int argc,
+  char **argv
+){
+  int rc;
+  sqlite3 *db;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+        " DB function-name", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  rc = sqlite3_create_function(db, argv[2], -1, SQLITE_UTF8, 0, 0, 0, 0);
+  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite_delete_collation DB collation-name
+**
+** Delete the collation sequence 'collation-name' from database handle 
+** DB. It is assumed that the collation sequence was created as UTF8 (the 
+** way the TCL interface does it).
+*/
+static int delete_collation(
+  void * clientData,
+  Tcl_Interp *interp,
+  int argc,
+  char **argv
+){
+  int rc;
+  sqlite3 *db;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+        " DB function-name", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  rc = sqlite3_create_collation(db, argv[2], SQLITE_UTF8, 0, 0);
+  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_get_autocommit DB
+**
+** Return true if the database DB is currently in auto-commit mode.
+** Return false if not.
+*/
+static int get_autocommit(
+  void * clientData,
+  Tcl_Interp *interp,
+  int argc,
+  char **argv
+){
+  char zBuf[30];
+  sqlite3 *db;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+        " DB", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  sprintf(zBuf, "%d", sqlite3_get_autocommit(db));
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_busy_timeout DB MS
+**
+** Set the busy timeout.  This is more easily done using the timeout
+** method of the TCL interface.  But we need a way to test the case
+** where it returns SQLITE_MISUSE.
+*/
+static int test_busy_timeout(
+  void * clientData,
+  Tcl_Interp *interp,
+  int argc,
+  char **argv
+){
+  int rc, ms;
+  sqlite3 *db;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+        " DB", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  if( Tcl_GetInt(interp, argv[2], &ms) ) return TCL_ERROR;
+  rc = sqlite3_busy_timeout(db, ms);
+  Tcl_AppendResult(interp, sqlite3TestErrorName(rc), 0);
+  return TCL_OK;
+}
+
+/*
+** Usage:  tcl_variable_type VARIABLENAME
+**
+** Return the name of the internal representation for the
+** value of the given variable.
+*/
+static int tcl_variable_type(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  Tcl_Obj *pVar;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "VARIABLE");
+    return TCL_ERROR;
+  }
+  pVar = Tcl_GetVar2Ex(interp, Tcl_GetString(objv[1]), 0, TCL_LEAVE_ERR_MSG);
+  if( pVar==0 ) return TCL_ERROR;
+  if( pVar->typePtr ){
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(pVar->typePtr->name, -1));
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_release_memory ?N?
+**
+** Attempt to release memory currently held but not actually required.
+** The integer N is the number of bytes we are trying to release.  The 
+** return value is the amount of memory actually released.
+*/
+static int test_release_memory(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) && !defined(SQLITE_OMIT_DISKIO)
+  int N;
+  int amt;
+  if( objc!=1 && objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "?N?");
+    return TCL_ERROR;
+  }
+  if( objc==2 ){
+    if( Tcl_GetIntFromObj(interp, objv[1], &N) ) return TCL_ERROR;
+  }else{
+    N = -1;
+  }
+  amt = sqlite3_release_memory(N);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(amt));
+#endif
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_soft_heap_limit ?N?
+**
+** Query or set the soft heap limit for the current thread.  The
+** limit is only changed if the N is present.  The previous limit
+** is returned.
+*/
+static int test_soft_heap_limit(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  static int softHeapLimit = 0;
+  int amt;
+  if( objc!=1 && objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "?N?");
+    return TCL_ERROR;
+  }
+  amt = softHeapLimit;
+  if( objc==2 ){
+    int N;
+    if( Tcl_GetIntFromObj(interp, objv[1], &N) ) return TCL_ERROR;
+    sqlite3_soft_heap_limit(N);
+    softHeapLimit = N;
+  }
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(amt));
+  return TCL_OK;
+}
+
+/*
+** Usage:   sqlite3_thread_cleanup
+**
+** Call the sqlite3_thread_cleanup API.
+*/
+static int test_thread_cleanup(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_thread_cleanup();
+  return TCL_OK;
+}
+
+
+/*
+** Usage:   sqlite3_pager_refcounts  DB
+**
+** Return a list of numbers which are the PagerRefcount for all
+** pagers on each database connection.
+*/
+static int test_pager_refcounts(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  int i;
+  int v, *a;
+  Tcl_Obj *pResult;
+
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " DB", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  pResult = Tcl_NewObj();
+  for(i=0; i<db->nDb; i++){
+    if( db->aDb[i].pBt==0 ){
+      v = -1;
+    }else{
+      sqlite3_mutex_enter(db->mutex);
+      a = sqlite3PagerStats(sqlite3BtreePager(db->aDb[i].pBt));
+      v = a[0];
+      sqlite3_mutex_leave(db->mutex);
+    }
+    Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(v));
+  }
+  Tcl_SetObjResult(interp, pResult);
+  return TCL_OK;
+}
+
+
+/*
+** tclcmd:   working_64bit_int
+**
+** Some TCL builds (ex: cygwin) do not support 64-bit integers.  This
+** leads to a number of test failures.  The present command checks the
+** TCL build to see whether or not it supports 64-bit integers.  It
+** returns TRUE if it does and FALSE if not.
+**
+** This command is used to warn users that their TCL build is defective
+** and that the errors they are seeing in the test scripts might be
+** a result of their defective TCL rather than problems in SQLite.
+*/
+static int working_64bit_int(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  Tcl_Obj *pTestObj;
+  int working = 0;
+
+  pTestObj = Tcl_NewWideIntObj(1000000*(i64)1234567890);
+  working = strcmp(Tcl_GetString(pTestObj), "1234567890000000")==0;
+  Tcl_DecrRefCount(pTestObj);
+  Tcl_SetObjResult(interp, Tcl_NewBooleanObj(working));
+  return TCL_OK;
+}
+
+
+/*
+** tclcmd:   vfs_unlink_test
+**
+** This TCL command unregisters the primary VFS and then registers
+** it back again.  This is used to test the ability to register a
+** VFS when none are previously registered, and the ability to 
+** unregister the only available VFS.  Ticket #2738
+*/
+static int vfs_unlink_test(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  int i;
+  sqlite3_vfs *pMain;
+  sqlite3_vfs *apVfs[20];
+  sqlite3_vfs one, two;
+
+  sqlite3_vfs_unregister(0);   /* Unregister of NULL is harmless */
+  one.zName = "__one";
+  two.zName = "__two";
+
+  /* Calling sqlite3_vfs_register with 2nd argument of 0 does not
+  ** change the default VFS
+  */
+  pMain = sqlite3_vfs_find(0);
+  sqlite3_vfs_register(&one, 0);
+  assert( pMain==0 || pMain==sqlite3_vfs_find(0) );
+  sqlite3_vfs_register(&two, 0);
+  assert( pMain==0 || pMain==sqlite3_vfs_find(0) );
+
+  /* We can find a VFS by its name */
+  assert( sqlite3_vfs_find("__one")==&one );
+  assert( sqlite3_vfs_find("__two")==&two );
+
+  /* Calling sqlite_vfs_register with non-zero second parameter changes the
+  ** default VFS, even if the 1st parameter is an existig VFS that is
+  ** previously registered as the non-default.
+  */
+  sqlite3_vfs_register(&one, 1);
+  assert( sqlite3_vfs_find("__one")==&one );
+  assert( sqlite3_vfs_find("__two")==&two );
+  assert( sqlite3_vfs_find(0)==&one );
+  sqlite3_vfs_register(&two, 1);
+  assert( sqlite3_vfs_find("__one")==&one );
+  assert( sqlite3_vfs_find("__two")==&two );
+  assert( sqlite3_vfs_find(0)==&two );
+  if( pMain ){
+    sqlite3_vfs_register(pMain, 1);
+    assert( sqlite3_vfs_find("__one")==&one );
+    assert( sqlite3_vfs_find("__two")==&two );
+    assert( sqlite3_vfs_find(0)==pMain );
+  }
+  
+  /* Unlink the default VFS.  Repeat until there are no more VFSes
+  ** registered.
+  */
+  for(i=0; i<sizeof(apVfs)/sizeof(apVfs[0]); i++){
+    apVfs[i] = sqlite3_vfs_find(0);
+    if( apVfs[i] ){
+      assert( apVfs[i]==sqlite3_vfs_find(apVfs[i]->zName) );
+      sqlite3_vfs_unregister(apVfs[i]);
+      assert( 0==sqlite3_vfs_find(apVfs[i]->zName) );
+    }
+  }
+  assert( 0==sqlite3_vfs_find(0) );
+  
+  /* Register the main VFS as non-default (will be made default, since
+  ** it'll be the only one in existence).
+  */
+  sqlite3_vfs_register(pMain, 0);
+  assert( sqlite3_vfs_find(0)==pMain );
+  
+  /* Un-register the main VFS again to restore an empty VFS list */
+  sqlite3_vfs_unregister(pMain);
+  assert( 0==sqlite3_vfs_find(0) );
+
+  /* Relink all VFSes in reverse order. */  
+  for(i=sizeof(apVfs)/sizeof(apVfs[0])-1; i>=0; i--){
+    if( apVfs[i] ){
+      sqlite3_vfs_register(apVfs[i], 1);
+      assert( apVfs[i]==sqlite3_vfs_find(0) );
+      assert( apVfs[i]==sqlite3_vfs_find(apVfs[i]->zName) );
+    }
+  }
+
+  /* Unregister out sample VFSes. */
+  sqlite3_vfs_unregister(&one);
+  sqlite3_vfs_unregister(&two);
+
+  /* Unregistering a VFS that is not currently registered is harmless */
+  sqlite3_vfs_unregister(&one);
+  sqlite3_vfs_unregister(&two);
+  assert( sqlite3_vfs_find("__one")==0 );
+  assert( sqlite3_vfs_find("__two")==0 );
+
+  /* We should be left with the original default VFS back as the
+  ** original */
+  assert( sqlite3_vfs_find(0)==pMain );
+
+  return TCL_OK;
+}
+
+/*
+** tclcmd:   vfs_initfail_test
+**
+** This TCL command attempts to vfs_find and vfs_register when the
+** sqlite3_initialize() interface is failing.  All calls should fail.
+*/
+static int vfs_initfail_test(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3_vfs one;
+  one.zName = "__one";
+
+  if( sqlite3_vfs_find(0) ) return TCL_ERROR;
+  sqlite3_vfs_register(&one, 0);
+  if( sqlite3_vfs_find(0) ) return TCL_ERROR;
+  sqlite3_vfs_register(&one, 1);
+  if( sqlite3_vfs_find(0) ) return TCL_ERROR;
+  return TCL_OK;
+}
+
+/*
+** Saved VFSes
+*/
+static sqlite3_vfs *apVfs[20];
+static int nVfs = 0;
+
+/*
+** tclcmd:   vfs_unregister_all
+**
+** Unregister all VFSes.
+*/
+static int vfs_unregister_all(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  int i;
+  for(i=0; i<ArraySize(apVfs); i++){
+    apVfs[i] = sqlite3_vfs_find(0);
+    if( apVfs[i]==0 ) break;
+    sqlite3_vfs_unregister(apVfs[i]);
+  }
+  nVfs = i;
+  return TCL_OK;
+}
+/*
+** tclcmd:   vfs_reregister_all
+**
+** Restore all VFSes that were removed using vfs_unregister_all
+*/
+static int vfs_reregister_all(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  int i;
+  for(i=0; i<nVfs; i++){
+    sqlite3_vfs_register(apVfs[i], i==0);
+  }
+  return TCL_OK;
+}
+
+
+/*
+** tclcmd:   file_control_test DB
+**
+** This TCL command runs the sqlite3_file_control interface and
+** verifies correct operation of the same.
+*/
+static int file_control_test(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  int iArg = 0;
+  sqlite3 *db;
+  int rc;
+
+  if( objc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " DB", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  rc = sqlite3_file_control(db, 0, 0, &iArg);
+  assert( rc==SQLITE_ERROR );
+  rc = sqlite3_file_control(db, "notadatabase", SQLITE_FCNTL_LOCKSTATE, &iArg);
+  assert( rc==SQLITE_ERROR );
+  rc = sqlite3_file_control(db, "main", -1, &iArg);
+  assert( rc==SQLITE_ERROR );
+  rc = sqlite3_file_control(db, "temp", -1, &iArg);
+  assert( rc==SQLITE_ERROR );
+  return TCL_OK;  
+}
+
+/*
+** tclcmd:   sqlite3_vfs_list
+**
+**   Return a tcl list containing the names of all registered vfs's.
+*/
+static int vfs_list(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3_vfs *pVfs;
+  Tcl_Obj *pRet = Tcl_NewObj();
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+  for(pVfs=sqlite3_vfs_find(0); pVfs; pVfs=pVfs->pNext){
+    Tcl_ListObjAppendElement(interp, pRet, Tcl_NewStringObj(pVfs->zName, -1));
+  }
+  Tcl_SetObjResult(interp, pRet);
+  return TCL_OK;  
+}
+
+/*
+** tclcmd:   sqlite3_limit DB ID VALUE
+**
+** This TCL command runs the sqlite3_limit interface and
+** verifies correct operation of the same.
+*/
+static int test_limit(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3 *db;
+  int rc;
+  static const struct {
+     char *zName;
+     int id;
+  } aId[] = {
+    { "SQLITE_LIMIT_LENGTH",              SQLITE_LIMIT_LENGTH               },
+    { "SQLITE_LIMIT_SQL_LENGTH",          SQLITE_LIMIT_SQL_LENGTH           },
+    { "SQLITE_LIMIT_COLUMN",              SQLITE_LIMIT_COLUMN               },
+    { "SQLITE_LIMIT_EXPR_DEPTH",          SQLITE_LIMIT_EXPR_DEPTH           },
+    { "SQLITE_LIMIT_COMPOUND_SELECT",     SQLITE_LIMIT_COMPOUND_SELECT      },
+    { "SQLITE_LIMIT_VDBE_OP",             SQLITE_LIMIT_VDBE_OP              },
+    { "SQLITE_LIMIT_FUNCTION_ARG",        SQLITE_LIMIT_FUNCTION_ARG         },
+    { "SQLITE_LIMIT_ATTACHED",            SQLITE_LIMIT_ATTACHED             },
+    { "SQLITE_LIMIT_LIKE_PATTERN_LENGTH", SQLITE_LIMIT_LIKE_PATTERN_LENGTH  },
+    { "SQLITE_LIMIT_VARIABLE_NUMBER",     SQLITE_LIMIT_VARIABLE_NUMBER      },
+    
+    /* Out of range test cases */
+    { "SQLITE_LIMIT_TOOSMALL",            -1,                               },
+    { "SQLITE_LIMIT_TOOBIG",              SQLITE_LIMIT_VARIABLE_NUMBER+1    },
+  };
+  int i, id;
+  int val;
+  const char *zId;
+
+  if( objc!=4 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " DB ID VALUE", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  zId = Tcl_GetString(objv[2]);
+  for(i=0; i<sizeof(aId)/sizeof(aId[0]); i++){
+    if( strcmp(zId, aId[i].zName)==0 ){
+      id = aId[i].id;
+      break;
+    }
+  }
+  if( i>=sizeof(aId)/sizeof(aId[0]) ){
+    Tcl_AppendResult(interp, "unknown limit type: ", zId, (char*)0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[3], &val) ) return TCL_ERROR;
+  rc = sqlite3_limit(db, id, val);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return TCL_OK;  
+}
+
+/*
+** tclcmd:  save_prng_state
+**
+** Save the state of the pseudo-random number generator.
+** At the same time, verify that sqlite3_test_control works even when
+** called with an out-of-range opcode.
+*/
+static int save_prng_state(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  int rc = sqlite3_test_control(9999);
+  assert( rc==0 );
+  rc = sqlite3_test_control(-1);
+  assert( rc==0 );
+  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SAVE);
+  return TCL_OK;
+}
+/*
+** tclcmd:  restore_prng_state
+*/
+static int restore_prng_state(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_RESTORE);
+  return TCL_OK;
+}
+/*
+** tclcmd:  reset_prng_state
+*/
+static int reset_prng_state(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_RESET);
+  return TCL_OK;
+}
+
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest1_Init(Tcl_Interp *interp){
+  extern int sqlite3_search_count;
+  extern int sqlite3_interrupt_count;
+  extern int sqlite3_open_file_count;
+  extern int sqlite3_sort_count;
+  extern int sqlite3_current_time;
+  extern int sqlite3_max_blobsize;
+  extern int sqlite3BtreeSharedCacheReport(void*,
+                                          Tcl_Interp*,int,Tcl_Obj*CONST*);
+  static struct {
+     char *zName;
+     Tcl_CmdProc *xProc;
+  } aCmd[] = {
+     { "db_enter",                      (Tcl_CmdProc*)db_enter               },
+     { "db_leave",                      (Tcl_CmdProc*)db_leave               },
+     { "sqlite3_mprintf_int",           (Tcl_CmdProc*)sqlite3_mprintf_int    },
+     { "sqlite3_mprintf_int64",         (Tcl_CmdProc*)sqlite3_mprintf_int64  },
+     { "sqlite3_mprintf_str",           (Tcl_CmdProc*)sqlite3_mprintf_str    },
+     { "sqlite3_snprintf_str",          (Tcl_CmdProc*)sqlite3_snprintf_str   },
+     { "sqlite3_mprintf_stronly",       (Tcl_CmdProc*)sqlite3_mprintf_stronly},
+     { "sqlite3_mprintf_double",        (Tcl_CmdProc*)sqlite3_mprintf_double },
+     { "sqlite3_mprintf_scaled",        (Tcl_CmdProc*)sqlite3_mprintf_scaled },
+     { "sqlite3_mprintf_hexdouble",   (Tcl_CmdProc*)sqlite3_mprintf_hexdouble},
+     { "sqlite3_mprintf_z_test",        (Tcl_CmdProc*)test_mprintf_z        },
+     { "sqlite3_mprintf_n_test",        (Tcl_CmdProc*)test_mprintf_n        },
+     { "sqlite3_snprintf_int",          (Tcl_CmdProc*)test_snprintf_int     },
+     { "sqlite3_last_insert_rowid",     (Tcl_CmdProc*)test_last_rowid       },
+     { "sqlite3_exec_printf",           (Tcl_CmdProc*)test_exec_printf      },
+     { "sqlite3_exec",                  (Tcl_CmdProc*)test_exec             },
+     { "sqlite3_exec_nr",               (Tcl_CmdProc*)test_exec_nr          },
+#ifndef SQLITE_OMIT_GET_TABLE
+     { "sqlite3_get_table_printf",      (Tcl_CmdProc*)test_get_table_printf },
+#endif
+     { "sqlite3_close",                 (Tcl_CmdProc*)sqlite_test_close     },
+     { "sqlite3_create_function",       (Tcl_CmdProc*)test_create_function  },
+     { "sqlite3_create_aggregate",      (Tcl_CmdProc*)test_create_aggregate },
+     { "sqlite_register_test_function", (Tcl_CmdProc*)test_register_func    },
+     { "sqlite_abort",                  (Tcl_CmdProc*)sqlite_abort          },
+     { "sqlite_bind",                   (Tcl_CmdProc*)test_bind             },
+     { "breakpoint",                    (Tcl_CmdProc*)test_breakpoint       },
+     { "sqlite3_key",                   (Tcl_CmdProc*)test_key              },
+     { "sqlite3_rekey",                 (Tcl_CmdProc*)test_rekey            },
+     { "sqlite_set_magic",              (Tcl_CmdProc*)sqlite_set_magic      },
+     { "sqlite3_interrupt",             (Tcl_CmdProc*)test_interrupt        },
+     { "sqlite_delete_function",        (Tcl_CmdProc*)delete_function       },
+     { "sqlite_delete_collation",       (Tcl_CmdProc*)delete_collation      },
+     { "sqlite3_get_autocommit",        (Tcl_CmdProc*)get_autocommit        },
+     { "sqlite3_stack_used",            (Tcl_CmdProc*)test_stack_used       },
+     { "sqlite3_busy_timeout",          (Tcl_CmdProc*)test_busy_timeout     },
+     { "printf",                        (Tcl_CmdProc*)test_printf           },
+     { "sqlite3IoTrace",              (Tcl_CmdProc*)test_io_trace         },
+  };
+  static struct {
+     char *zName;
+     Tcl_ObjCmdProc *xProc;
+     void *clientData;
+  } aObjCmd[] = {
+     { "sqlite3_connection_pointer",    get_sqlite_pointer, 0 },
+     { "sqlite3_bind_int",              test_bind_int,      0 },
+     { "sqlite3_bind_zeroblob",         test_bind_zeroblob, 0 },
+     { "sqlite3_bind_int64",            test_bind_int64,    0 },
+     { "sqlite3_bind_double",           test_bind_double,   0 },
+     { "sqlite3_bind_null",             test_bind_null     ,0 },
+     { "sqlite3_bind_text",             test_bind_text     ,0 },
+     { "sqlite3_bind_text16",           test_bind_text16   ,0 },
+     { "sqlite3_bind_blob",             test_bind_blob     ,0 },
+     { "sqlite3_bind_parameter_count",  test_bind_parameter_count, 0},
+     { "sqlite3_bind_parameter_name",   test_bind_parameter_name,  0},
+     { "sqlite3_bind_parameter_index",  test_bind_parameter_index, 0},
+     { "sqlite3_clear_bindings",        test_clear_bindings, 0},
+     { "sqlite3_sleep",                 test_sleep,          0},
+     { "sqlite3_errcode",               test_errcode       ,0 },
+     { "sqlite3_errmsg",                test_errmsg        ,0 },
+     { "sqlite3_errmsg16",              test_errmsg16      ,0 },
+     { "sqlite3_open",                  test_open          ,0 },
+     { "sqlite3_open16",                test_open16        ,0 },
+     { "sqlite3_complete16",            test_complete16    ,0 },
+
+     { "sqlite3_prepare",               test_prepare       ,0 },
+     { "sqlite3_prepare16",             test_prepare16     ,0 },
+     { "sqlite3_prepare_v2",            test_prepare_v2    ,0 },
+     { "sqlite3_prepare_tkt3134",       test_prepare_tkt3134, 0},
+     { "sqlite3_prepare16_v2",          test_prepare16_v2  ,0 },
+     { "sqlite3_finalize",              test_finalize      ,0 },
+     { "sqlite3_reset",                 test_reset         ,0 },
+     { "sqlite3_expired",               test_expired       ,0 },
+     { "sqlite3_transfer_bindings",     test_transfer_bind ,0 },
+     { "sqlite3_changes",               test_changes       ,0 },
+     { "sqlite3_step",                  test_step          ,0 },
+     { "sqlite3_next_stmt",             test_next_stmt     ,0 },
+
+     { "sqlite3_release_memory",        test_release_memory,     0},
+     { "sqlite3_soft_heap_limit",       test_soft_heap_limit,    0},
+     { "sqlite3_thread_cleanup",        test_thread_cleanup,     0},
+     { "sqlite3_pager_refcounts",       test_pager_refcounts,    0},
+
+     { "sqlite3_load_extension",        test_load_extension,     0},
+     { "sqlite3_enable_load_extension", test_enable_load,        0},
+     { "sqlite3_extended_result_codes", test_extended_result_codes, 0},
+     { "sqlite3_limit",                 test_limit,                 0},
+
+     { "save_prng_state",               save_prng_state,    0 },
+     { "restore_prng_state",            restore_prng_state, 0 },
+     { "reset_prng_state",              reset_prng_state,   0 },
+
+     /* sqlite3_column_*() API */
+     { "sqlite3_column_count",          test_column_count  ,0 },
+     { "sqlite3_data_count",            test_data_count    ,0 },
+     { "sqlite3_column_type",           test_column_type   ,0 },
+     { "sqlite3_column_blob",           test_column_blob   ,0 },
+     { "sqlite3_column_double",         test_column_double ,0 },
+     { "sqlite3_column_int64",          test_column_int64  ,0 },
+     { "sqlite3_column_text",       test_stmt_utf8,  sqlite3_column_text      },
+     { "sqlite3_column_name",       test_stmt_utf8,  sqlite3_column_name      },
+     { "sqlite3_column_int",        test_stmt_int,   sqlite3_column_int       },
+     { "sqlite3_column_bytes",      test_stmt_int,   sqlite3_column_bytes     },
+#ifndef SQLITE_OMIT_DECLTYPE
+     { "sqlite3_column_decltype",   test_stmt_utf8,  sqlite3_column_decltype  },
+#endif
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+{ "sqlite3_column_database_name", test_stmt_utf8, sqlite3_column_database_name},
+{ "sqlite3_column_table_name", test_stmt_utf8, sqlite3_column_table_name},
+{ "sqlite3_column_origin_name", test_stmt_utf8, sqlite3_column_origin_name},
+#endif
+
+#ifndef SQLITE_OMIT_UTF16
+     { "sqlite3_column_bytes16",    test_stmt_int,   sqlite3_column_bytes16   },
+     { "sqlite3_column_text16",     test_stmt_utf16, sqlite3_column_text16    },
+     { "sqlite3_column_name16",     test_stmt_utf16, sqlite3_column_name16    },
+     { "add_alignment_test_collations", add_alignment_test_collations, 0      },
+#ifndef SQLITE_OMIT_DECLTYPE
+     { "sqlite3_column_decltype16", test_stmt_utf16, sqlite3_column_decltype16},
+#endif
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+{"sqlite3_column_database_name16",
+  test_stmt_utf16, sqlite3_column_database_name16},
+{"sqlite3_column_table_name16", test_stmt_utf16, sqlite3_column_table_name16},
+{"sqlite3_column_origin_name16", test_stmt_utf16, sqlite3_column_origin_name16},
+#endif
+#endif
+     { "sqlite3_create_collation_v2", test_create_collation_v2, 0 },
+     { "sqlite3_global_recover",     test_global_recover, 0   },
+     { "working_64bit_int",          working_64bit_int,   0   },
+     { "vfs_unlink_test",            vfs_unlink_test,     0   },
+     { "vfs_initfail_test",          vfs_initfail_test,   0   },
+     { "vfs_unregister_all",         vfs_unregister_all,  0   },
+     { "vfs_reregister_all",         vfs_reregister_all,  0   },
+     { "file_control_test",          file_control_test,   0   },
+     { "sqlite3_vfs_list",           vfs_list,     0   },
+
+     /* Functions from os.h */
+#ifndef SQLITE_OMIT_UTF16
+     { "add_test_collate",        test_collate, 0            },
+     { "add_test_collate_needed", test_collate_needed, 0     },
+     { "add_test_function",       test_function, 0           },
+#endif
+     { "sqlite3_test_errstr",     test_errstr, 0             },
+     { "tcl_variable_type",       tcl_variable_type, 0       },
+#ifndef SQLITE_OMIT_SHARED_CACHE
+     { "sqlite3_enable_shared_cache", test_enable_shared, 0  },
+     { "sqlite3_shared_cache_report", sqlite3BtreeSharedCacheReport, 0},
+#endif
+     { "sqlite3_libversion_number", test_libversion_number, 0  },
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+     { "sqlite3_table_column_metadata", test_table_column_metadata, 0  },
+#endif
+#ifndef SQLITE_OMIT_INCRBLOB
+     { "sqlite3_blob_read",  test_blob_read, 0  },
+     { "sqlite3_blob_write", test_blob_write, 0  },
+#endif
+  };
+  static int bitmask_size = sizeof(Bitmask)*8;
+  int i;
+  extern int sqlite3_sync_count, sqlite3_fullsync_count;
+  extern int sqlite3_opentemp_count;
+  extern int sqlite3_like_count;
+  extern int sqlite3_xferopt_count;
+  extern int sqlite3_pager_readdb_count;
+  extern int sqlite3_pager_writedb_count;
+  extern int sqlite3_pager_writej_count;
+  extern int sqlite3_pager_pgfree_count;
+#if SQLITE_OS_UNIX && defined(SQLITE_TEST) && SQLITE_THREADSAFE
+  extern int threadsOverrideEachOthersLocks;
+#endif
+#if SQLITE_OS_WIN
+  extern int sqlite3_os_type;
+#endif
+#ifdef SQLITE_DEBUG
+  extern int sqlite3WhereTrace;
+  extern int sqlite3OSTrace;
+  extern int sqlite3VdbeAddopTrace;
+#endif
+#ifdef SQLITE_TEST
+  extern int sqlite3_enable_in_opt;
+  extern char sqlite3_query_plan[];
+  static char *query_plan = sqlite3_query_plan;
+#endif
+
+  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
+    Tcl_CreateCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
+  }
+  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
+    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 
+        aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
+  }
+  Tcl_LinkVar(interp, "sqlite_search_count", 
+      (char*)&sqlite3_search_count, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_sort_count", 
+      (char*)&sqlite3_sort_count, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite3_max_blobsize", 
+      (char*)&sqlite3_max_blobsize, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_like_count", 
+      (char*)&sqlite3_like_count, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_interrupt_count", 
+      (char*)&sqlite3_interrupt_count, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_open_file_count", 
+      (char*)&sqlite3_open_file_count, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_current_time", 
+      (char*)&sqlite3_current_time, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite3_xferopt_count",
+      (char*)&sqlite3_xferopt_count, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite3_pager_readdb_count",
+      (char*)&sqlite3_pager_readdb_count, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite3_pager_writedb_count",
+      (char*)&sqlite3_pager_writedb_count, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite3_pager_writej_count",
+      (char*)&sqlite3_pager_writej_count, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite3_pager_pgfree_count",
+      (char*)&sqlite3_pager_pgfree_count, TCL_LINK_INT);
+#ifndef SQLITE_OMIT_UTF16
+  Tcl_LinkVar(interp, "unaligned_string_counter",
+      (char*)&unaligned_string_counter, TCL_LINK_INT);
+#endif
+#if SQLITE_OS_UNIX && defined(SQLITE_TEST) && SQLITE_THREADSAFE
+  Tcl_LinkVar(interp, "threadsOverrideEachOthersLocks",
+      (char*)&threadsOverrideEachOthersLocks, TCL_LINK_INT);
+#endif
+#ifndef SQLITE_OMIT_UTF16
+  Tcl_LinkVar(interp, "sqlite_last_needed_collation",
+      (char*)&pzNeededCollation, TCL_LINK_STRING|TCL_LINK_READ_ONLY);
+#endif
+#if SQLITE_OS_WIN
+  Tcl_LinkVar(interp, "sqlite_os_type",
+      (char*)&sqlite3_os_type, TCL_LINK_INT);
+#endif
+#ifdef SQLITE_TEST
+  Tcl_LinkVar(interp, "sqlite_query_plan",
+      (char*)&query_plan, TCL_LINK_STRING|TCL_LINK_READ_ONLY);
+#endif
+#ifdef SQLITE_DEBUG
+  Tcl_LinkVar(interp, "sqlite_addop_trace",
+      (char*)&sqlite3VdbeAddopTrace, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_where_trace",
+      (char*)&sqlite3WhereTrace, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_os_trace",
+      (char*)&sqlite3OSTrace, TCL_LINK_INT);
+#endif
+#ifndef SQLITE_OMIT_DISKIO
+  Tcl_LinkVar(interp, "sqlite_opentemp_count",
+      (char*)&sqlite3_opentemp_count, TCL_LINK_INT);
+#endif
+  Tcl_LinkVar(interp, "sqlite_static_bind_value",
+      (char*)&sqlite_static_bind_value, TCL_LINK_STRING);
+  Tcl_LinkVar(interp, "sqlite_static_bind_nbyte",
+      (char*)&sqlite_static_bind_nbyte, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_temp_directory",
+      (char*)&sqlite3_temp_directory, TCL_LINK_STRING);
+  Tcl_LinkVar(interp, "bitmask_size",
+      (char*)&bitmask_size, TCL_LINK_INT|TCL_LINK_READ_ONLY);
+  Tcl_LinkVar(interp, "sqlite_sync_count",
+      (char*)&sqlite3_sync_count, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_fullsync_count",
+      (char*)&sqlite3_fullsync_count, TCL_LINK_INT);
+#ifdef SQLITE_TEST
+  Tcl_LinkVar(interp, "sqlite_enable_in_opt",
+      (char*)&sqlite3_enable_in_opt, TCL_LINK_INT);
+#endif
+  return TCL_OK;
+}
diff --git a/third_party/sqlite/src/test2.c b/third_party/sqlite/src/test2.c
new file mode 100755
index 0000000..c27a9fd
--- /dev/null
+++ b/third_party/sqlite/src/test2.c
@@ -0,0 +1,659 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing the pager.c module in SQLite.  This code
+** is not included in the SQLite library.  It is used for automated
+** testing of the SQLite library.
+**
+** $Id: test2.c,v 1.59 2008/07/12 14:52:20 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "tcl.h"
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+/*
+** Interpret an SQLite error number
+*/
+static char *errorName(int rc){
+  char *zName;
+  switch( rc ){
+    case SQLITE_OK:         zName = "SQLITE_OK";          break;
+    case SQLITE_ERROR:      zName = "SQLITE_ERROR";       break;
+    case SQLITE_PERM:       zName = "SQLITE_PERM";        break;
+    case SQLITE_ABORT:      zName = "SQLITE_ABORT";       break;
+    case SQLITE_BUSY:       zName = "SQLITE_BUSY";        break;
+    case SQLITE_NOMEM:      zName = "SQLITE_NOMEM";       break;
+    case SQLITE_READONLY:   zName = "SQLITE_READONLY";    break;
+    case SQLITE_INTERRUPT:  zName = "SQLITE_INTERRUPT";   break;
+    case SQLITE_IOERR:      zName = "SQLITE_IOERR";       break;
+    case SQLITE_CORRUPT:    zName = "SQLITE_CORRUPT";     break;
+    case SQLITE_FULL:       zName = "SQLITE_FULL";        break;
+    case SQLITE_CANTOPEN:   zName = "SQLITE_CANTOPEN";    break;
+    case SQLITE_PROTOCOL:   zName = "SQLITE_PROTOCOL";    break;
+    case SQLITE_EMPTY:      zName = "SQLITE_EMPTY";       break;
+    case SQLITE_SCHEMA:     zName = "SQLITE_SCHEMA";      break;
+    case SQLITE_CONSTRAINT: zName = "SQLITE_CONSTRAINT";  break;
+    case SQLITE_MISMATCH:   zName = "SQLITE_MISMATCH";    break;
+    case SQLITE_MISUSE:     zName = "SQLITE_MISUSE";      break;
+    case SQLITE_NOLFS:      zName = "SQLITE_NOLFS";       break;
+    default:                zName = "SQLITE_Unknown";     break;
+  }
+  return zName;
+}
+
+/*
+** Page size and reserved size used for testing.
+*/
+static int test_pagesize = 1024;
+
+/*
+** Usage:   pager_open FILENAME N-PAGE
+**
+** Open a new pager
+*/
+static int pager_open(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  u16 pageSize;
+  Pager *pPager;
+  int nPage;
+  int rc;
+  char zBuf[100];
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FILENAME N-PAGE\"", 0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetInt(interp, argv[2], &nPage) ) return TCL_ERROR;
+  rc = sqlite3PagerOpen(sqlite3_vfs_find(0), &pPager, argv[1], 0, 0,
+      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_MAIN_DB);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  sqlite3PagerSetCachesize(pPager, nPage);
+  pageSize = test_pagesize;
+  sqlite3PagerSetPagesize(pPager, &pageSize);
+  sqlite3_snprintf(sizeof(zBuf),zBuf,"%p",pPager);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage:   pager_close ID
+**
+** Close the given pager.
+*/
+static int pager_close(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Pager *pPager;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pPager = sqlite3TestTextToPtr(argv[1]);
+  rc = sqlite3PagerClose(pPager);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   pager_rollback ID
+**
+** Rollback changes
+*/
+static int pager_rollback(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Pager *pPager;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pPager = sqlite3TestTextToPtr(argv[1]);
+  rc = sqlite3PagerRollback(pPager);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   pager_commit ID
+**
+** Commit all changes
+*/
+static int pager_commit(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Pager *pPager;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pPager = sqlite3TestTextToPtr(argv[1]);
+  rc = sqlite3PagerCommitPhaseOne(pPager, 0, 0, 0);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  rc = sqlite3PagerCommitPhaseTwo(pPager);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   pager_stmt_begin ID
+**
+** Start a new checkpoint.
+*/
+static int pager_stmt_begin(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Pager *pPager;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pPager = sqlite3TestTextToPtr(argv[1]);
+  rc = sqlite3PagerStmtBegin(pPager);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   pager_stmt_rollback ID
+**
+** Rollback changes to a checkpoint
+*/
+static int pager_stmt_rollback(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Pager *pPager;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pPager = sqlite3TestTextToPtr(argv[1]);
+  rc = sqlite3PagerStmtRollback(pPager);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   pager_stmt_commit ID
+**
+** Commit changes to a checkpoint
+*/
+static int pager_stmt_commit(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Pager *pPager;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pPager = sqlite3TestTextToPtr(argv[1]);
+  rc = sqlite3PagerStmtCommit(pPager);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   pager_stats ID
+**
+** Return pager statistics.
+*/
+static int pager_stats(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Pager *pPager;
+  int i, *a;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pPager = sqlite3TestTextToPtr(argv[1]);
+  a = sqlite3PagerStats(pPager);
+  for(i=0; i<9; i++){
+    static char *zName[] = {
+      "ref", "page", "max", "size", "state", "err",
+      "hit", "miss", "ovfl",
+    };
+    char zBuf[100];
+    Tcl_AppendElement(interp, zName[i]);
+    sqlite3_snprintf(sizeof(zBuf),zBuf,"%d",a[i]);
+    Tcl_AppendElement(interp, zBuf);
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   pager_pagecount ID
+**
+** Return the size of the database file.
+*/
+static int pager_pagecount(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Pager *pPager;
+  char zBuf[100];
+  int nPage;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pPager = sqlite3TestTextToPtr(argv[1]);
+  sqlite3PagerPagecount(pPager, &nPage);
+  sqlite3_snprintf(sizeof(zBuf), zBuf, "%d", nPage);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage:   page_get ID PGNO
+**
+** Return a pointer to a page from the database.
+*/
+static int page_get(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Pager *pPager;
+  char zBuf[100];
+  DbPage *pPage;
+  int pgno;
+  int rc;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID PGNO\"", 0);
+    return TCL_ERROR;
+  }
+  pPager = sqlite3TestTextToPtr(argv[1]);
+  if( Tcl_GetInt(interp, argv[2], &pgno) ) return TCL_ERROR;
+  rc = sqlite3PagerGet(pPager, pgno, &pPage);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  sqlite3_snprintf(sizeof(zBuf),zBuf,"%p",pPage);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage:   page_lookup ID PGNO
+**
+** Return a pointer to a page if the page is already in cache.
+** If not in cache, return an empty string.
+*/
+static int page_lookup(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Pager *pPager;
+  char zBuf[100];
+  DbPage *pPage;
+  int pgno;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID PGNO\"", 0);
+    return TCL_ERROR;
+  }
+  pPager = sqlite3TestTextToPtr(argv[1]);
+  if( Tcl_GetInt(interp, argv[2], &pgno) ) return TCL_ERROR;
+  pPage = sqlite3PagerLookup(pPager, pgno);
+  if( pPage ){
+    sqlite3_snprintf(sizeof(zBuf),zBuf,"%p",pPage);
+    Tcl_AppendResult(interp, zBuf, 0);
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   pager_truncate ID PGNO
+*/
+static int pager_truncate(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Pager *pPager;
+  int rc;
+  int pgno;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID PGNO\"", 0);
+    return TCL_ERROR;
+  }
+  pPager = sqlite3TestTextToPtr(argv[1]);
+  if( Tcl_GetInt(interp, argv[2], &pgno) ) return TCL_ERROR;
+  rc = sqlite3PagerTruncate(pPager, pgno);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+
+/*
+** Usage:   page_unref PAGE
+**
+** Drop a pointer to a page.
+*/
+static int page_unref(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  DbPage *pPage;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " PAGE\"", 0);
+    return TCL_ERROR;
+  }
+  pPage = (DbPage *)sqlite3TestTextToPtr(argv[1]);
+  rc = sqlite3PagerUnref(pPage);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   page_read PAGE
+**
+** Return the content of a page
+*/
+static int page_read(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  char zBuf[100];
+  DbPage *pPage;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " PAGE\"", 0);
+    return TCL_ERROR;
+  }
+  pPage = sqlite3TestTextToPtr(argv[1]);
+  memcpy(zBuf, sqlite3PagerGetData(pPage), sizeof(zBuf));
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage:   page_number PAGE
+**
+** Return the page number for a page.
+*/
+static int page_number(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  char zBuf[100];
+  DbPage *pPage;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " PAGE\"", 0);
+    return TCL_ERROR;
+  }
+  pPage = (DbPage *)sqlite3TestTextToPtr(argv[1]);
+  sqlite3_snprintf(sizeof(zBuf), zBuf, "%d", sqlite3PagerPagenumber(pPage));
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage:   page_write PAGE DATA
+**
+** Write something into a page.
+*/
+static int page_write(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  DbPage *pPage;
+  char *pData;
+  int rc;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " PAGE DATA\"", 0);
+    return TCL_ERROR;
+  }
+  pPage = (DbPage *)sqlite3TestTextToPtr(argv[1]);
+  rc = sqlite3PagerWrite(pPage);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  pData = sqlite3PagerGetData(pPage);
+  strncpy(pData, argv[2], test_pagesize-1);
+  pData[test_pagesize-1] = 0;
+  return TCL_OK;
+}
+
+#ifndef SQLITE_OMIT_DISKIO
+/*
+** Usage:   fake_big_file  N  FILENAME
+**
+** Write a few bytes at the N megabyte point of FILENAME.  This will
+** create a large file.  If the file was a valid SQLite database, then
+** the next time the database is opened, SQLite will begin allocating
+** new pages after N.  If N is 2096 or bigger, this will test the
+** ability of SQLite to write to large files.
+*/
+static int fake_big_file(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  sqlite3_vfs *pVfs;
+  sqlite3_file *fd = 0;
+  int rc;
+  int n;
+  i64 offset;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " N-MEGABYTES FILE\"", 0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetInt(interp, argv[1], &n) ) return TCL_ERROR;
+
+  pVfs = sqlite3_vfs_find(0);
+  rc = sqlite3OsOpenMalloc(pVfs, argv[2], &fd, 
+      (SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_DB), 0
+  );
+  if( rc ){
+    Tcl_AppendResult(interp, "open failed: ", errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  offset = n;
+  offset *= 1024*1024;
+  rc = sqlite3OsWrite(fd, "Hello, World!", 14, offset);
+  sqlite3OsCloseFree(fd);
+  if( rc ){
+    Tcl_AppendResult(interp, "write failed: ", errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+#endif
+
+
+/*
+** sqlite3BitvecBuiltinTest SIZE PROGRAM
+**
+** Invoke the SQLITE_TESTCTRL_BITVEC_TEST operator on test_control.
+** See comments on sqlite3BitvecBuiltinTest() for additional information.
+*/
+static int testBitvecBuiltinTest(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int sz, rc;
+  int nProg = 0;
+  int aProg[100];
+  const char *z;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+                     " SIZE PROGRAM\"", (void*)0);
+  }
+  if( Tcl_GetInt(interp, argv[1], &sz) ) return TCL_ERROR;
+  z = argv[2];
+  while( nProg<99 && *z ){
+    while( *z && !isdigit(*z) ){ z++; }
+    if( *z==0 ) break;
+    aProg[nProg++] = atoi(z);
+    while( isdigit(*z) ){ z++; }
+  }
+  aProg[nProg] = 0;
+  rc = sqlite3_test_control(SQLITE_TESTCTRL_BITVEC_TEST, sz, aProg);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return TCL_OK;
+}  
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest2_Init(Tcl_Interp *interp){
+  extern int sqlite3_io_error_persist;
+  extern int sqlite3_io_error_pending;
+  extern int sqlite3_io_error_hit;
+  extern int sqlite3_io_error_hardhit;
+  extern int sqlite3_diskfull_pending;
+  extern int sqlite3_diskfull;
+  extern int sqlite3_pager_n_sort_bucket;
+  static struct {
+    char *zName;
+    Tcl_CmdProc *xProc;
+  } aCmd[] = {
+    { "pager_open",              (Tcl_CmdProc*)pager_open          },
+    { "pager_close",             (Tcl_CmdProc*)pager_close         },
+    { "pager_commit",            (Tcl_CmdProc*)pager_commit        },
+    { "pager_rollback",          (Tcl_CmdProc*)pager_rollback      },
+    { "pager_stmt_begin",        (Tcl_CmdProc*)pager_stmt_begin    },
+    { "pager_stmt_commit",       (Tcl_CmdProc*)pager_stmt_commit   },
+    { "pager_stmt_rollback",     (Tcl_CmdProc*)pager_stmt_rollback },
+    { "pager_stats",             (Tcl_CmdProc*)pager_stats         },
+    { "pager_pagecount",         (Tcl_CmdProc*)pager_pagecount     },
+    { "page_get",                (Tcl_CmdProc*)page_get            },
+    { "page_lookup",             (Tcl_CmdProc*)page_lookup         },
+    { "page_unref",              (Tcl_CmdProc*)page_unref          },
+    { "page_read",               (Tcl_CmdProc*)page_read           },
+    { "page_write",              (Tcl_CmdProc*)page_write          },
+    { "page_number",             (Tcl_CmdProc*)page_number         },
+    { "pager_truncate",          (Tcl_CmdProc*)pager_truncate      },
+#ifndef SQLITE_OMIT_DISKIO
+    { "fake_big_file",           (Tcl_CmdProc*)fake_big_file       },
+#endif
+    { "sqlite3BitvecBuiltinTest",(Tcl_CmdProc*)testBitvecBuiltinTest},
+  };
+  int i;
+  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
+    Tcl_CreateCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
+  }
+  Tcl_LinkVar(interp, "sqlite_io_error_pending",
+     (char*)&sqlite3_io_error_pending, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_io_error_persist",
+     (char*)&sqlite3_io_error_persist, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_io_error_hit",
+     (char*)&sqlite3_io_error_hit, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_io_error_hardhit",
+     (char*)&sqlite3_io_error_hardhit, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_diskfull_pending",
+     (char*)&sqlite3_diskfull_pending, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_diskfull",
+     (char*)&sqlite3_diskfull, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_pending_byte",
+     (char*)&sqlite3_pending_byte, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_pager_n_sort_bucket",
+     (char*)&sqlite3_pager_n_sort_bucket, TCL_LINK_INT);
+  return TCL_OK;
+}
diff --git a/third_party/sqlite/src/test3.c b/third_party/sqlite/src/test3.c
new file mode 100755
index 0000000..6b06dfc
--- /dev/null
+++ b/third_party/sqlite/src/test3.c
@@ -0,0 +1,1605 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing the btree.c module in SQLite.  This code
+** is not included in the SQLite library.  It is used for automated
+** testing of the SQLite library.
+**
+** $Id: test3.c,v 1.100 2008/07/12 14:52:20 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "btreeInt.h"
+#include "tcl.h"
+#include <stdlib.h>
+#include <string.h>
+
+/*
+** Interpret an SQLite error number
+*/
+static char *errorName(int rc){
+  char *zName;
+  switch( rc ){
+    case SQLITE_OK:         zName = "SQLITE_OK";          break;
+    case SQLITE_ERROR:      zName = "SQLITE_ERROR";       break;
+    case SQLITE_PERM:       zName = "SQLITE_PERM";        break;
+    case SQLITE_ABORT:      zName = "SQLITE_ABORT";       break;
+    case SQLITE_BUSY:       zName = "SQLITE_BUSY";        break;
+    case SQLITE_NOMEM:      zName = "SQLITE_NOMEM";       break;
+    case SQLITE_READONLY:   zName = "SQLITE_READONLY";    break;
+    case SQLITE_INTERRUPT:  zName = "SQLITE_INTERRUPT";   break;
+    case SQLITE_IOERR:      zName = "SQLITE_IOERR";       break;
+    case SQLITE_CORRUPT:    zName = "SQLITE_CORRUPT";     break;
+    case SQLITE_FULL:       zName = "SQLITE_FULL";        break;
+    case SQLITE_CANTOPEN:   zName = "SQLITE_CANTOPEN";    break;
+    case SQLITE_PROTOCOL:   zName = "SQLITE_PROTOCOL";    break;
+    case SQLITE_EMPTY:      zName = "SQLITE_EMPTY";       break;
+    case SQLITE_LOCKED:     zName = "SQLITE_LOCKED";      break;
+    default:                zName = "SQLITE_Unknown";     break;
+  }
+  return zName;
+}
+
+/*
+** A bogus sqlite3 connection structure for use in the btree
+** tests.
+*/
+static sqlite3 sDb;
+static int nRefSqlite3 = 0;
+
+/*
+** Usage:   btree_open FILENAME NCACHE FLAGS
+**
+** Open a new database
+*/
+static int btree_open(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int rc, nCache, flags;
+  char zBuf[100];
+  if( argc!=4 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FILENAME NCACHE FLAGS\"", 0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetInt(interp, argv[2], &nCache) ) return TCL_ERROR;
+  if( Tcl_GetInt(interp, argv[3], &flags) ) return TCL_ERROR;
+  nRefSqlite3++;
+  if( nRefSqlite3==1 ){
+    sDb.pVfs = sqlite3_vfs_find(0);
+    sDb.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
+    sqlite3_mutex_enter(sDb.mutex);
+  }
+  rc = sqlite3BtreeOpen(argv[1], &sDb, &pBt, flags,
+     SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_MAIN_DB);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  sqlite3BtreeSetCacheSize(pBt, nCache);
+  sqlite3_snprintf(sizeof(zBuf), zBuf,"%p", pBt);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_close ID
+**
+** Close the given database.
+*/
+static int btree_close(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  rc = sqlite3BtreeClose(pBt);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  nRefSqlite3--;
+  if( nRefSqlite3==0 ){
+    sqlite3_mutex_leave(sDb.mutex);
+    sqlite3_mutex_free(sDb.mutex);
+    sDb.mutex = 0;
+    sDb.pVfs = 0;
+  }
+  return TCL_OK;
+}
+
+
+/*
+** Usage:   btree_begin_transaction ID
+**
+** Start a new transaction
+*/
+static int btree_begin_transaction(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pBt);
+  rc = sqlite3BtreeBeginTrans(pBt, 1);
+  sqlite3BtreeLeave(pBt);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_rollback ID
+**
+** Rollback changes
+*/
+static int btree_rollback(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pBt);
+  rc = sqlite3BtreeRollback(pBt);
+  sqlite3BtreeLeave(pBt);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_commit ID
+**
+** Commit all changes
+*/
+static int btree_commit(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pBt);
+  rc = sqlite3BtreeCommit(pBt);
+  sqlite3BtreeLeave(pBt);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_begin_statement ID
+**
+** Start a new statement transaction
+*/
+static int btree_begin_statement(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pBt);
+  rc = sqlite3BtreeBeginStmt(pBt);
+  sqlite3BtreeLeave(pBt);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_rollback_statement ID
+**
+** Rollback changes
+*/
+static int btree_rollback_statement(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pBt);
+  rc = sqlite3BtreeRollbackStmt(pBt);
+  sqlite3BtreeLeave(pBt);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_commit_statement ID
+**
+** Commit all changes
+*/
+static int btree_commit_statement(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pBt);
+  rc = sqlite3BtreeCommitStmt(pBt);
+  sqlite3BtreeLeave(pBt);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_create_table ID FLAGS
+**
+** Create a new table in the database
+*/
+static int btree_create_table(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int rc, iTable, flags;
+  char zBuf[30];
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID FLAGS\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  if( Tcl_GetInt(interp, argv[2], &flags) ) return TCL_ERROR;
+  sqlite3BtreeEnter(pBt);
+  rc = sqlite3BtreeCreateTable(pBt, &iTable, flags);
+  sqlite3BtreeLeave(pBt);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  sqlite3_snprintf(sizeof(zBuf), zBuf, "%d", iTable);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_drop_table ID TABLENUM
+**
+** Delete an entire table from the database
+*/
+static int btree_drop_table(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int iTable;
+  int rc;
+  int notUsed1;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID TABLENUM\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
+  sqlite3BtreeEnter(pBt);
+  rc = sqlite3BtreeDropTable(pBt, iTable, &notUsed1);
+  sqlite3BtreeLeave(pBt);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_clear_table ID TABLENUM
+**
+** Remove all entries from the given table but keep the table around.
+*/
+static int btree_clear_table(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int iTable;
+  int rc;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID TABLENUM\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
+  sqlite3BtreeEnter(pBt);
+  rc = sqlite3BtreeClearTable(pBt, iTable);
+  sqlite3BtreeLeave(pBt);
+  if( rc!=SQLITE_OK ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_get_meta ID
+**
+** Return meta data
+*/
+static int btree_get_meta(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int rc;
+  int i;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  for(i=0; i<SQLITE_N_BTREE_META; i++){
+    char zBuf[30];
+    u32 v;
+    sqlite3BtreeEnter(pBt);
+    rc = sqlite3BtreeGetMeta(pBt, i, &v);
+    sqlite3BtreeLeave(pBt);
+    if( rc!=SQLITE_OK ){
+      Tcl_AppendResult(interp, errorName(rc), 0);
+      return TCL_ERROR;
+    }
+    sqlite3_snprintf(sizeof(zBuf), zBuf,"%d",v);
+    Tcl_AppendElement(interp, zBuf);
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_update_meta ID METADATA...
+**
+** Return meta data
+*/
+static int btree_update_meta(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int rc;
+  int i;
+  int aMeta[SQLITE_N_BTREE_META];
+
+  if( argc!=2+SQLITE_N_BTREE_META ){
+    char zBuf[30];
+    sqlite3_snprintf(sizeof(zBuf), zBuf,"%d",SQLITE_N_BTREE_META);
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID METADATA...\" (METADATA is ", zBuf, " integers)", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  for(i=1; i<SQLITE_N_BTREE_META; i++){
+    if( Tcl_GetInt(interp, argv[i+2], &aMeta[i]) ) return TCL_ERROR;
+  }
+  for(i=1; i<SQLITE_N_BTREE_META; i++){
+    sqlite3BtreeEnter(pBt);
+    rc = sqlite3BtreeUpdateMeta(pBt, i, aMeta[i]);
+    sqlite3BtreeLeave(pBt);
+    if( rc!=SQLITE_OK ){
+      Tcl_AppendResult(interp, errorName(rc), 0);
+      return TCL_ERROR;
+    }
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_pager_stats ID
+**
+** Returns pager statistics
+*/
+static int btree_pager_stats(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int i;
+  int *a;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+ 
+  /* Normally in this file, with a b-tree handle opened using the 
+  ** [btree_open] command it is safe to call sqlite3BtreeEnter() directly.
+  ** But this function is sometimes called with a btree handle obtained
+  ** from an open SQLite connection (using [btree_from_db]). In this case
+  ** we need to obtain the mutex for the controlling SQLite handle before
+  ** it is safe to call sqlite3BtreeEnter().
+  */
+  sqlite3_mutex_enter(pBt->db->mutex);
+
+  sqlite3BtreeEnter(pBt);
+  a = sqlite3PagerStats(sqlite3BtreePager(pBt));
+  for(i=0; i<11; i++){
+    static char *zName[] = {
+      "ref", "page", "max", "size", "state", "err",
+      "hit", "miss", "ovfl", "read", "write"
+    };
+    char zBuf[100];
+    Tcl_AppendElement(interp, zName[i]);
+    sqlite3_snprintf(sizeof(zBuf), zBuf,"%d",a[i]);
+    Tcl_AppendElement(interp, zBuf);
+  }
+  sqlite3BtreeLeave(pBt);
+
+  /* Release the mutex on the SQLite handle that controls this b-tree */
+  sqlite3_mutex_leave(pBt->db->mutex);
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_integrity_check ID ROOT ...
+**
+** Look through every page of the given BTree file to verify correct
+** formatting and linkage.  Return a line of text for each problem found.
+** Return an empty string if everything worked.
+*/
+static int btree_integrity_check(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int nRoot;
+  int *aRoot;
+  int i;
+  int nErr;
+  char *zResult;
+
+  if( argc<3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID ROOT ...\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  nRoot = argc-2;
+  aRoot = (int*)sqlite3_malloc( sizeof(int)*(argc-2) );
+  for(i=0; i<argc-2; i++){
+    if( Tcl_GetInt(interp, argv[i+2], &aRoot[i]) ) return TCL_ERROR;
+  }
+#ifndef SQLITE_OMIT_INTEGRITY_CHECK
+  sqlite3BtreeEnter(pBt);
+  zResult = sqlite3BtreeIntegrityCheck(pBt, aRoot, nRoot, 10000, &nErr);
+  sqlite3BtreeLeave(pBt);
+#else
+  zResult = 0;
+#endif
+  sqlite3_free((void*)aRoot);
+  if( zResult ){
+    Tcl_AppendResult(interp, zResult, 0);
+    sqlite3_free(zResult); 
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_cursor_list ID
+**
+** Print information about all cursors to standard output for debugging.
+*/
+static int btree_cursor_list(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pBt);
+  sqlite3BtreeCursorList(pBt);
+  sqlite3BtreeLeave(pBt);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_cursor ID TABLENUM WRITEABLE
+**
+** Create a new cursor.  Return the ID for the cursor.
+*/
+static int btree_cursor(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int iTable;
+  BtCursor *pCur;
+  int rc;
+  int wrFlag;
+  char zBuf[30];
+
+  if( argc!=4 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID TABLENUM WRITEABLE\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
+  if( Tcl_GetBoolean(interp, argv[3], &wrFlag) ) return TCL_ERROR;
+  pCur = (BtCursor *)ckalloc(sqlite3BtreeCursorSize());
+  memset(pCur, 0, sqlite3BtreeCursorSize());
+  sqlite3BtreeEnter(pBt);
+  rc = sqlite3BtreeCursor(pBt, iTable, wrFlag, 0, pCur);
+  sqlite3BtreeLeave(pBt);
+  if( rc ){
+    ckfree((char *)pCur);
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  sqlite3_snprintf(sizeof(zBuf), zBuf,"%p", pCur);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_close_cursor ID
+**
+** Close a cursor opened using btree_cursor.
+*/
+static int btree_close_cursor(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  Btree *pBt;
+  int rc;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  pBt = pCur->pBtree;
+  sqlite3BtreeEnter(pBt);
+  rc = sqlite3BtreeCloseCursor(pCur);
+  sqlite3BtreeLeave(pBt);
+  ckfree((char *)pCur);
+  if( rc ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_move_to ID KEY
+**
+** Move the cursor to the entry with the given key.
+*/
+static int btree_move_to(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int rc;
+  int res;
+  char zBuf[20];
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID KEY\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pCur->pBtree);
+  if( sqlite3BtreeFlags(pCur) & BTREE_INTKEY ){
+    int iKey;
+    if( Tcl_GetInt(interp, argv[2], &iKey) ){
+      sqlite3BtreeLeave(pCur->pBtree);
+      return TCL_ERROR;
+    }
+    rc = sqlite3BtreeMoveto(pCur, 0, 0, iKey, 0, &res);
+  }else{
+    rc = sqlite3BtreeMoveto(pCur, argv[2], 0, strlen(argv[2]), 0, &res);  
+  }
+  sqlite3BtreeLeave(pCur->pBtree);
+  if( rc ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  if( res<0 ) res = -1;
+  if( res>0 ) res = 1;
+  sqlite3_snprintf(sizeof(zBuf), zBuf,"%d",res);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_delete ID
+**
+** Delete the entry that the cursor is pointing to
+*/
+static int btree_delete(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int rc;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pCur->pBtree);
+  rc = sqlite3BtreeDelete(pCur);
+  sqlite3BtreeLeave(pCur->pBtree);
+  if( rc ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_insert ID KEY DATA ?NZERO?
+**
+** Create a new entry with the given key and data.  If an entry already
+** exists with the same key the old entry is overwritten.
+*/
+static int btree_insert(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  BtCursor *pCur;
+  int rc;
+  int nZero;
+
+  if( objc!=4 && objc!=5 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "ID KEY DATA ?NZERO?");
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(Tcl_GetString(objv[1]));
+  if( objc==5 ){
+    if( Tcl_GetIntFromObj(interp, objv[4], &nZero) ) return TCL_ERROR;
+  }else{
+    nZero = 0;
+  }
+  sqlite3BtreeEnter(pCur->pBtree);
+  if( sqlite3BtreeFlags(pCur) & BTREE_INTKEY ){
+    i64 iKey;
+    int len;
+    unsigned char *pBuf;
+    if( Tcl_GetWideIntFromObj(interp, objv[2], &iKey) ){
+      sqlite3BtreeLeave(pCur->pBtree);
+      return TCL_ERROR;
+    }
+    pBuf = Tcl_GetByteArrayFromObj(objv[3], &len);
+    rc = sqlite3BtreeInsert(pCur, 0, iKey, pBuf, len, nZero, 0);
+  }else{
+    int keylen;
+    int dlen;
+    unsigned char *pKBuf;
+    unsigned char *pDBuf;
+    pKBuf = Tcl_GetByteArrayFromObj(objv[2], &keylen);
+    pDBuf = Tcl_GetByteArrayFromObj(objv[3], &dlen);
+    rc = sqlite3BtreeInsert(pCur, pKBuf, keylen, pDBuf, dlen, nZero, 0);
+  }
+  sqlite3BtreeLeave(pCur->pBtree);
+  if( rc ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_next ID
+**
+** Move the cursor to the next entry in the table.  Return 0 on success
+** or 1 if the cursor was already on the last entry in the table or if
+** the table is empty.
+*/
+static int btree_next(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int rc;
+  int res = 0;
+  char zBuf[100];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pCur->pBtree);
+  rc = sqlite3BtreeNext(pCur, &res);
+  sqlite3BtreeLeave(pCur->pBtree);
+  if( rc ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  sqlite3_snprintf(sizeof(zBuf),zBuf,"%d",res);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_prev ID
+**
+** Move the cursor to the previous entry in the table.  Return 0 on
+** success and 1 if the cursor was already on the first entry in
+** the table or if the table was empty.
+*/
+static int btree_prev(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int rc;
+  int res = 0;
+  char zBuf[100];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pCur->pBtree);
+  rc = sqlite3BtreePrevious(pCur, &res);
+  sqlite3BtreeLeave(pCur->pBtree);
+  if( rc ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  sqlite3_snprintf(sizeof(zBuf),zBuf,"%d",res);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_first ID
+**
+** Move the cursor to the first entry in the table.  Return 0 if the
+** cursor was left point to something and 1 if the table is empty.
+*/
+static int btree_first(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int rc;
+  int res = 0;
+  char zBuf[100];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pCur->pBtree);
+  rc = sqlite3BtreeFirst(pCur, &res);
+  sqlite3BtreeLeave(pCur->pBtree);
+  if( rc ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  sqlite3_snprintf(sizeof(zBuf),zBuf,"%d",res);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_last ID
+**
+** Move the cursor to the last entry in the table.  Return 0 if the
+** cursor was left point to something and 1 if the table is empty.
+*/
+static int btree_last(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int rc;
+  int res = 0;
+  char zBuf[100];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pCur->pBtree);
+  rc = sqlite3BtreeLast(pCur, &res);
+  sqlite3BtreeLeave(pCur->pBtree);
+  if( rc ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    return TCL_ERROR;
+  }
+  sqlite3_snprintf(sizeof(zBuf),zBuf,"%d",res);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_eof ID
+**
+** Return TRUE if the given cursor is not pointing at a valid entry.
+** Return FALSE if the cursor does point to a valid entry.
+*/
+static int btree_eof(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int rc;
+  char zBuf[50];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pCur->pBtree);
+  rc = sqlite3BtreeEof(pCur);
+  sqlite3BtreeLeave(pCur->pBtree);
+  sqlite3_snprintf(sizeof(zBuf),zBuf, "%d", rc);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_keysize ID
+**
+** Return the number of bytes of key.  For an INTKEY table, this
+** returns the key itself.
+*/
+static int btree_keysize(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  u64 n;
+  char zBuf[50];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pCur->pBtree);
+  sqlite3BtreeKeySize(pCur, (i64*)&n);
+  sqlite3BtreeLeave(pCur->pBtree);
+  sqlite3_snprintf(sizeof(zBuf),zBuf, "%llu", n);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_key ID
+**
+** Return the key for the entry at which the cursor is pointing.
+*/
+static int btree_key(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int rc;
+  u64 n;
+  char *zBuf;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pCur->pBtree);
+  sqlite3BtreeKeySize(pCur, (i64*)&n);
+  if( sqlite3BtreeFlags(pCur) & BTREE_INTKEY ){
+    char zBuf2[60];
+    sqlite3_snprintf(sizeof(zBuf2),zBuf2, "%llu", n);
+    Tcl_AppendResult(interp, zBuf2, 0);
+  }else{
+    zBuf = sqlite3_malloc( n+1 );
+    rc = sqlite3BtreeKey(pCur, 0, n, zBuf);
+    if( rc ){
+      sqlite3BtreeLeave(pCur->pBtree);
+      Tcl_AppendResult(interp, errorName(rc), 0);
+      return TCL_ERROR;
+    }
+    zBuf[n] = 0;
+    Tcl_AppendResult(interp, zBuf, 0);
+    sqlite3_free(zBuf);
+  }
+  sqlite3BtreeLeave(pCur->pBtree);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_data ID ?N?
+**
+** Return the data for the entry at which the cursor is pointing.
+*/
+static int btree_data(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int rc;
+  u32 n;
+  char *zBuf;
+
+  if( argc!=2 && argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pCur->pBtree);
+  if( argc==2 ){
+    sqlite3BtreeDataSize(pCur, &n);
+  }else{
+    n = atoi(argv[2]);
+  }
+  zBuf = sqlite3_malloc( n+1 );
+  rc = sqlite3BtreeData(pCur, 0, n, zBuf);
+  sqlite3BtreeLeave(pCur->pBtree);
+  if( rc ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    sqlite3_free(zBuf);
+    return TCL_ERROR;
+  }
+  zBuf[n] = 0;
+  Tcl_AppendResult(interp, zBuf, 0);
+  sqlite3_free(zBuf);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_fetch_key ID AMT
+**
+** Use the sqlite3BtreeKeyFetch() routine to get AMT bytes of the key.
+** If sqlite3BtreeKeyFetch() fails, return an empty string.
+*/
+static int btree_fetch_key(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int n;
+  int amt;
+  u64 nKey;
+  const char *zBuf;
+  char zStatic[1000];
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID AMT\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
+  sqlite3BtreeEnter(pCur->pBtree);
+  sqlite3BtreeKeySize(pCur, (i64*)&nKey);
+  zBuf = sqlite3BtreeKeyFetch(pCur, &amt);
+  if( zBuf && amt>=n ){
+    assert( nKey<sizeof(zStatic) );
+    if( n>0 ) nKey = n;
+    memcpy(zStatic, zBuf, (int)nKey); 
+    zStatic[nKey] = 0;
+    Tcl_AppendResult(interp, zStatic, 0);
+  }
+  sqlite3BtreeLeave(pCur->pBtree);
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_fetch_data ID AMT
+**
+** Use the sqlite3BtreeDataFetch() routine to get AMT bytes of the key.
+** If sqlite3BtreeDataFetch() fails, return an empty string.
+*/
+static int btree_fetch_data(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int n;
+  int amt;
+  u32 nData;
+  const char *zBuf;
+  char zStatic[1000];
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID AMT\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
+  sqlite3BtreeEnter(pCur->pBtree);
+  sqlite3BtreeDataSize(pCur, &nData);
+  zBuf = sqlite3BtreeDataFetch(pCur, &amt);
+  if( zBuf && amt>=n ){
+    assert( nData<sizeof(zStatic) );
+    if( n>0 ) nData = n;
+    memcpy(zStatic, zBuf, (int)nData); 
+    zStatic[nData] = 0;
+    Tcl_AppendResult(interp, zStatic, 0);
+  }
+  sqlite3BtreeLeave(pCur->pBtree);
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_payload_size ID
+**
+** Return the number of bytes of payload
+*/
+static int btree_payload_size(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int n2;
+  u64 n1;
+  char zBuf[50];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  sqlite3BtreeEnter(pCur->pBtree);
+  if( sqlite3BtreeFlags(pCur) & BTREE_INTKEY ){
+    n1 = 0;
+  }else{
+    sqlite3BtreeKeySize(pCur, (i64*)&n1);
+  }
+  sqlite3BtreeDataSize(pCur, (u32*)&n2);
+  sqlite3BtreeLeave(pCur->pBtree);
+  sqlite3_snprintf(sizeof(zBuf),zBuf, "%d", (int)(n1+n2));
+  Tcl_AppendResult(interp, zBuf, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Usage:   btree_cursor_info ID ?UP-CNT?
+**
+** Return integers containing information about the entry the
+** cursor is pointing to:
+**
+**   aResult[0] =  The page number
+**   aResult[1] =  The entry number
+**   aResult[2] =  Total number of entries on this page
+**   aResult[3] =  Cell size (local payload + header)
+**   aResult[4] =  Number of free bytes on this page
+**   aResult[5] =  Number of free blocks on the page
+**   aResult[6] =  Total payload size (local + overflow)
+**   aResult[7] =  Header size in bytes
+**   aResult[8] =  Local payload size
+**   aResult[9] =  Parent page number
+**   aResult[10]=  Page number of the first overflow page
+*/
+static int btree_cursor_info(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  BtCursor *pCur;
+  int rc;
+  int i, j;
+  int up;
+  int aResult[11];
+  char zBuf[400];
+
+  if( argc!=2 && argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID ?UP-CNT?\"", 0);
+    return TCL_ERROR;
+  }
+  pCur = sqlite3TestTextToPtr(argv[1]);
+  if( argc==3 ){
+    if( Tcl_GetInt(interp, argv[2], &up) ) return TCL_ERROR;
+  }else{
+    up = 0;
+  }
+  sqlite3BtreeEnter(pCur->pBtree);
+  rc = sqlite3BtreeCursorInfo(pCur, aResult, up);
+  if( rc ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    sqlite3BtreeLeave(pCur->pBtree);
+    return TCL_ERROR;
+  }
+  j = 0;
+  for(i=0; i<sizeof(aResult)/sizeof(aResult[0]); i++){
+    sqlite3_snprintf(40,&zBuf[j]," %d", aResult[i]);
+    j += strlen(&zBuf[j]);
+  }
+  sqlite3BtreeLeave(pCur->pBtree);
+  Tcl_AppendResult(interp, &zBuf[1], 0);
+  return SQLITE_OK;
+}
+
+/*
+** Copied from btree.c:
+*/
+static u32 t4Get4byte(unsigned char *p){
+  return (p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
+}
+
+/*
+**   btree_ovfl_info  BTREE  CURSOR
+**
+** Given a cursor, return the sequence of pages number that form the
+** overflow pages for the data of the entry that the cursor is point
+** to.
+*/ 
+static int btree_ovfl_info(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  BtCursor *pCur;
+  Pager *pPager;
+  int rc;
+  int n;
+  int dataSize;
+  u32 pgno;
+  void *pPage;
+  int aResult[11];
+  char zElem[100];
+  Tcl_DString str;
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
+                    " BTREE CURSOR", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  pCur = sqlite3TestTextToPtr(argv[2]);
+  if( (*(void**)pCur) != (void*)pBt ){
+    Tcl_AppendResult(interp, "Cursor ", argv[2], " does not belong to btree ",
+       argv[1], 0);
+    return TCL_ERROR;
+  }
+  sqlite3BtreeEnter(pBt);
+  pPager = sqlite3BtreePager(pBt);
+  rc = sqlite3BtreeCursorInfo(pCur, aResult, 0);
+  if( rc ){
+    Tcl_AppendResult(interp, errorName(rc), 0);
+    sqlite3BtreeLeave(pBt);
+    return TCL_ERROR;
+  }
+  dataSize = pBt->pBt->usableSize;
+  Tcl_DStringInit(&str);
+  n = aResult[6] - aResult[8];
+  n = (n + dataSize - 1)/dataSize;
+  pgno = (u32)aResult[10];
+  while( pgno && n-- ){
+    DbPage *pDbPage;
+    sprintf(zElem, "%d", pgno);
+    Tcl_DStringAppendElement(&str, zElem);
+    if( sqlite3PagerGet(pPager, pgno, &pDbPage)!=SQLITE_OK ){
+      Tcl_DStringFree(&str);
+      Tcl_AppendResult(interp, "unable to get page ", zElem, 0);
+      sqlite3BtreeLeave(pBt);
+      return TCL_ERROR;
+    }
+    pPage = sqlite3PagerGetData(pDbPage);
+    pgno = t4Get4byte((unsigned char*)pPage);
+    sqlite3PagerUnref(pDbPage);
+  }
+  sqlite3BtreeLeave(pBt);
+  Tcl_DStringResult(interp, &str);
+  return SQLITE_OK;
+}
+
+/*
+** The command is provided for the purpose of setting breakpoints.
+** in regression test scripts.
+**
+** By setting a GDB breakpoint on this procedure and executing the
+** btree_breakpoint command in a test script, we can stop GDB at
+** the point in the script where the btree_breakpoint command is
+** inserted.  This is useful for debugging.
+*/
+static int btree_breakpoint(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  return TCL_OK;
+}
+
+/*
+** usage:   varint_test  START  MULTIPLIER  COUNT  INCREMENT
+**
+** This command tests the putVarint() and getVarint()
+** routines, both for accuracy and for speed.
+**
+** An integer is written using putVarint() and read back with
+** getVarint() and varified to be unchanged.  This repeats COUNT
+** times.  The first integer is START*MULTIPLIER.  Each iteration
+** increases the integer by INCREMENT.
+**
+** This command returns nothing if it works.  It returns an error message
+** if something goes wrong.
+*/
+static int btree_varint_test(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  u32 start, mult, count, incr;
+  u64 in, out;
+  int n1, n2, i, j;
+  unsigned char zBuf[100];
+  if( argc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " START MULTIPLIER COUNT INCREMENT\"", 0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetInt(interp, argv[1], (int*)&start) ) return TCL_ERROR;
+  if( Tcl_GetInt(interp, argv[2], (int*)&mult) ) return TCL_ERROR;
+  if( Tcl_GetInt(interp, argv[3], (int*)&count) ) return TCL_ERROR;
+  if( Tcl_GetInt(interp, argv[4], (int*)&incr) ) return TCL_ERROR;
+  in = start;
+  in *= mult;
+  for(i=0; i<count; i++){
+    char zErr[200];
+    n1 = putVarint(zBuf, in);
+    if( n1>9 || n1<1 ){
+      sprintf(zErr, "putVarint returned %d - should be between 1 and 9", n1);
+      Tcl_AppendResult(interp, zErr, 0);
+      return TCL_ERROR;
+    }
+    n2 = getVarint(zBuf, &out);
+    if( n1!=n2 ){
+      sprintf(zErr, "putVarint returned %d and getVarint returned %d", n1, n2);
+      Tcl_AppendResult(interp, zErr, 0);
+      return TCL_ERROR;
+    }
+    if( in!=out ){
+      sprintf(zErr, "Wrote 0x%016llx and got back 0x%016llx", in, out);
+      Tcl_AppendResult(interp, zErr, 0);
+      return TCL_ERROR;
+    }
+    if( (in & 0xffffffff)==in ){
+      u32 out32;
+      n2 = getVarint32(zBuf, out32);
+      out = out32;
+      if( n1!=n2 ){
+        sprintf(zErr, "putVarint returned %d and GetVarint32 returned %d", 
+                  n1, n2);
+        Tcl_AppendResult(interp, zErr, 0);
+        return TCL_ERROR;
+      }
+      if( in!=out ){
+        sprintf(zErr, "Wrote 0x%016llx and got back 0x%016llx from GetVarint32",
+            in, out);
+        Tcl_AppendResult(interp, zErr, 0);
+        return TCL_ERROR;
+      }
+    }
+
+    /* In order to get realistic timings, run getVarint 19 more times.
+    ** This is because getVarint is called about 20 times more often
+    ** than putVarint.
+    */
+    for(j=0; j<19; j++){
+      getVarint(zBuf, &out);
+    }
+    in += incr;
+  }
+  return TCL_OK;
+}
+
+/*
+** usage:   btree_from_db  DB-HANDLE
+**
+** This command returns the btree handle for the main database associated
+** with the database-handle passed as the argument. Example usage:
+**
+** sqlite3 db test.db
+** set bt [btree_from_db db]
+*/
+static int btree_from_db(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  char zBuf[100];
+  Tcl_CmdInfo info;
+  sqlite3 *db;
+  Btree *pBt;
+  int iDb = 0;
+
+  if( argc!=2 && argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " DB-HANDLE ?N?\"", 0);
+    return TCL_ERROR;
+  }
+
+  if( 1!=Tcl_GetCommandInfo(interp, argv[1], &info) ){
+    Tcl_AppendResult(interp, "No such db-handle: \"", argv[1], "\"", 0);
+    return TCL_ERROR;
+  }
+  if( argc==3 ){
+    iDb = atoi(argv[2]);
+  }
+
+  db = *((sqlite3 **)info.objClientData);
+  assert( db );
+
+  pBt = db->aDb[iDb].pBt;
+  sqlite3_snprintf(sizeof(zBuf), zBuf, "%p", pBt);
+  Tcl_SetResult(interp, zBuf, TCL_VOLATILE);
+  return TCL_OK;
+}
+
+
+/*
+** usage:   btree_set_cache_size ID NCACHE
+**
+** Set the size of the cache used by btree $ID.
+*/
+static int btree_set_cache_size(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int nCache;
+  Btree *pBt;
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " BT NCACHE\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  if( Tcl_GetInt(interp, argv[2], &nCache) ) return TCL_ERROR;
+
+  sqlite3_mutex_enter(pBt->db->mutex);
+  sqlite3BtreeEnter(pBt);
+  sqlite3BtreeSetCacheSize(pBt, nCache);
+  sqlite3BtreeLeave(pBt);
+  sqlite3_mutex_leave(pBt->db->mutex);
+
+  return TCL_OK;
+}
+
+/*
+** Usage:   btree_ismemdb ID
+**
+** Return true if the B-Tree is in-memory.
+*/
+static int btree_ismemdb(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  Btree *pBt;
+  int res;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID\"", 0);
+    return TCL_ERROR;
+  }
+  pBt = sqlite3TestTextToPtr(argv[1]);
+  sqlite3_mutex_enter(pBt->db->mutex);
+  sqlite3BtreeEnter(pBt);
+  res = sqlite3PagerIsMemdb(sqlite3BtreePager(pBt));
+  sqlite3BtreeLeave(pBt);
+  sqlite3_mutex_leave(pBt->db->mutex);
+  Tcl_SetObjResult(interp, Tcl_NewBooleanObj(res));
+  return SQLITE_OK;
+}
+
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest3_Init(Tcl_Interp *interp){
+  static struct {
+     char *zName;
+     Tcl_CmdProc *xProc;
+  } aCmd[] = {
+     { "btree_open",               (Tcl_CmdProc*)btree_open               },
+     { "btree_close",              (Tcl_CmdProc*)btree_close              },
+     { "btree_begin_transaction",  (Tcl_CmdProc*)btree_begin_transaction  },
+     { "btree_commit",             (Tcl_CmdProc*)btree_commit             },
+     { "btree_rollback",           (Tcl_CmdProc*)btree_rollback           },
+     { "btree_create_table",       (Tcl_CmdProc*)btree_create_table       },
+     { "btree_drop_table",         (Tcl_CmdProc*)btree_drop_table         },
+     { "btree_clear_table",        (Tcl_CmdProc*)btree_clear_table        },
+     { "btree_get_meta",           (Tcl_CmdProc*)btree_get_meta           },
+     { "btree_update_meta",        (Tcl_CmdProc*)btree_update_meta        },
+     { "btree_pager_stats",        (Tcl_CmdProc*)btree_pager_stats        },
+     { "btree_cursor",             (Tcl_CmdProc*)btree_cursor             },
+     { "btree_close_cursor",       (Tcl_CmdProc*)btree_close_cursor       },
+     { "btree_move_to",            (Tcl_CmdProc*)btree_move_to            },
+     { "btree_delete",             (Tcl_CmdProc*)btree_delete             },
+     { "btree_next",               (Tcl_CmdProc*)btree_next               },
+     { "btree_prev",               (Tcl_CmdProc*)btree_prev               },
+     { "btree_eof",                (Tcl_CmdProc*)btree_eof                },
+     { "btree_keysize",            (Tcl_CmdProc*)btree_keysize            },
+     { "btree_key",                (Tcl_CmdProc*)btree_key                },
+     { "btree_data",               (Tcl_CmdProc*)btree_data               },
+     { "btree_fetch_key",          (Tcl_CmdProc*)btree_fetch_key          },
+     { "btree_fetch_data",         (Tcl_CmdProc*)btree_fetch_data         },
+     { "btree_payload_size",       (Tcl_CmdProc*)btree_payload_size       },
+     { "btree_first",              (Tcl_CmdProc*)btree_first              },
+     { "btree_last",               (Tcl_CmdProc*)btree_last               },
+     { "btree_integrity_check",    (Tcl_CmdProc*)btree_integrity_check    },
+     { "btree_breakpoint",         (Tcl_CmdProc*)btree_breakpoint         },
+     { "btree_varint_test",        (Tcl_CmdProc*)btree_varint_test        },
+     { "btree_begin_statement",    (Tcl_CmdProc*)btree_begin_statement    },
+     { "btree_commit_statement",   (Tcl_CmdProc*)btree_commit_statement   },
+     { "btree_rollback_statement", (Tcl_CmdProc*)btree_rollback_statement },
+     { "btree_from_db",            (Tcl_CmdProc*)btree_from_db            },
+     { "btree_set_cache_size",     (Tcl_CmdProc*)btree_set_cache_size     },
+     { "btree_cursor_info",        (Tcl_CmdProc*)btree_cursor_info        },
+     { "btree_ovfl_info",          (Tcl_CmdProc*)btree_ovfl_info          },
+     { "btree_cursor_list",        (Tcl_CmdProc*)btree_cursor_list        },
+     { "btree_ismemdb",            (Tcl_CmdProc*)btree_ismemdb            },
+  };
+  int i;
+
+  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
+    Tcl_CreateCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
+  }
+
+  /* The btree_insert command is implemented using the tcl 'object'
+  ** interface, not the string interface like the other commands in this
+  ** file. This is so binary data can be inserted into btree tables.
+  */
+  Tcl_CreateObjCommand(interp, "btree_insert", btree_insert, 0, 0);
+  return TCL_OK;
+}
diff --git a/third_party/sqlite/src/test4.c b/third_party/sqlite/src/test4.c
new file mode 100755
index 0000000..de5d3a2
--- /dev/null
+++ b/third_party/sqlite/src/test4.c
@@ -0,0 +1,716 @@
+/*
+** 2003 December 18
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing the the SQLite library in a multithreaded environment.
+**
+** $Id: test4.c,v 1.23 2008/07/28 19:34:54 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "tcl.h"
+#if defined(SQLITE_OS_UNIX) && OS_UNIX==1 && SQLITE_THREADSAFE
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <sched.h>
+#include <ctype.h>
+
+/*
+** Each thread is controlled by an instance of the following
+** structure.
+*/
+typedef struct Thread Thread;
+struct Thread {
+  /* The first group of fields are writable by the master and read-only
+  ** to the thread. */
+  char *zFilename;       /* Name of database file */
+  void (*xOp)(Thread*);  /* next operation to do */
+  char *zArg;            /* argument usable by xOp */
+  int opnum;             /* Operation number */
+  int busy;              /* True if this thread is in use */
+
+  /* The next group of fields are writable by the thread but read-only to the
+  ** master. */
+  int completed;        /* Number of operations completed */
+  sqlite3 *db;           /* Open database */
+  sqlite3_stmt *pStmt;     /* Pending operation */
+  char *zErr;           /* operation error */
+  char *zStaticErr;     /* Static error message */
+  int rc;               /* operation return code */
+  int argc;             /* number of columns in result */
+  const char *argv[100];    /* result columns */
+  const char *colv[100];    /* result column names */
+};
+
+/*
+** There can be as many as 26 threads running at once.  Each is named
+** by a capital letter: A, B, C, ..., Y, Z.
+*/
+#define N_THREAD 26
+static Thread threadset[N_THREAD];
+
+
+/*
+** The main loop for a thread.  Threads use busy waiting. 
+*/
+static void *thread_main(void *pArg){
+  Thread *p = (Thread*)pArg;
+  if( p->db ){
+    sqlite3_close(p->db);
+  }
+  sqlite3_open(p->zFilename, &p->db);
+  if( SQLITE_OK!=sqlite3_errcode(p->db) ){
+    p->zErr = strdup(sqlite3_errmsg(p->db));
+    sqlite3_close(p->db);
+    p->db = 0;
+  }
+  p->pStmt = 0;
+  p->completed = 1;
+  while( p->opnum<=p->completed ) sched_yield();
+  while( p->xOp ){
+    if( p->zErr && p->zErr!=p->zStaticErr ){
+      sqlite3_free(p->zErr);
+      p->zErr = 0;
+    }
+    (*p->xOp)(p);
+    p->completed++;
+    while( p->opnum<=p->completed ) sched_yield();
+  }
+  if( p->pStmt ){
+    sqlite3_finalize(p->pStmt);
+    p->pStmt = 0;
+  }
+  if( p->db ){
+    sqlite3_close(p->db);
+    p->db = 0;
+  }
+  if( p->zErr && p->zErr!=p->zStaticErr ){
+    sqlite3_free(p->zErr);
+    p->zErr = 0;
+  }
+  p->completed++;
+  sqlite3_thread_cleanup();
+  return 0;
+}
+
+/*
+** Get a thread ID which is an upper case letter.  Return the index.
+** If the argument is not a valid thread ID put an error message in
+** the interpreter and return -1.
+*/
+static int parse_thread_id(Tcl_Interp *interp, const char *zArg){
+  if( zArg==0 || zArg[0]==0 || zArg[1]!=0 || !isupper((unsigned char)zArg[0]) ){
+    Tcl_AppendResult(interp, "thread ID must be an upper case letter", 0);
+    return -1;
+  }
+  return zArg[0] - 'A';
+}
+
+/*
+** Usage:    thread_create NAME  FILENAME
+**
+** NAME should be an upper case letter.  Start the thread running with
+** an open connection to the given database.
+*/
+static int tcl_thread_create(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  pthread_t x;
+  int rc;
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID FILENAME", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( threadset[i].busy ){
+    Tcl_AppendResult(interp, "thread ", argv[1], " is already running", 0);
+    return TCL_ERROR;
+  }
+  threadset[i].busy = 1;
+  sqlite3_free(threadset[i].zFilename);
+  threadset[i].zFilename = sqlite3DbStrDup(0, argv[2]);
+  threadset[i].opnum = 1;
+  threadset[i].completed = 0;
+  rc = pthread_create(&x, 0, thread_main, &threadset[i]);
+  if( rc ){
+    Tcl_AppendResult(interp, "failed to create the thread", 0);
+    sqlite3_free(threadset[i].zFilename);
+    threadset[i].busy = 0;
+    return TCL_ERROR;
+  }
+  pthread_detach(x);
+  return TCL_OK;
+}
+
+/*
+** Wait for a thread to reach its idle state.
+*/
+static void thread_wait(Thread *p){
+  while( p->opnum>p->completed ) sched_yield();
+}
+
+/*
+** Usage:  thread_wait ID
+**
+** Wait on thread ID to reach its idle state.
+*/
+static int tcl_thread_wait(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  thread_wait(&threadset[i]);
+  return TCL_OK;
+}
+
+/*
+** Stop a thread.
+*/
+static void stop_thread(Thread *p){
+  thread_wait(p);
+  p->xOp = 0;
+  p->opnum++;
+  thread_wait(p);
+  sqlite3_free(p->zArg);
+  p->zArg = 0;
+  sqlite3_free(p->zFilename);
+  p->zFilename = 0;
+  p->busy = 0;
+}
+
+/*
+** Usage:  thread_halt ID
+**
+** Cause a thread to shut itself down.  Wait for the shutdown to be
+** completed.  If ID is "*" then stop all threads.
+*/
+static int tcl_thread_halt(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  if( argv[1][0]=='*' && argv[1][1]==0 ){
+    for(i=0; i<N_THREAD; i++){
+      if( threadset[i].busy ) stop_thread(&threadset[i]);
+    }
+  }else{
+    i = parse_thread_id(interp, argv[1]);
+    if( i<0 ) return TCL_ERROR;
+    if( !threadset[i].busy ){
+      Tcl_AppendResult(interp, "no such thread", 0);
+      return TCL_ERROR;
+    }
+    stop_thread(&threadset[i]);
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage: thread_argc  ID
+**
+** Wait on the most recent thread_step to complete, then return the
+** number of columns in the result set.
+*/
+static int tcl_thread_argc(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  char zBuf[100];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  thread_wait(&threadset[i]);
+  sprintf(zBuf, "%d", threadset[i].argc);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: thread_argv  ID   N
+**
+** Wait on the most recent thread_step to complete, then return the
+** value of the N-th columns in the result set.
+*/
+static int tcl_thread_argv(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  int n;
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID N", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
+  thread_wait(&threadset[i]);
+  if( n<0 || n>=threadset[i].argc ){
+    Tcl_AppendResult(interp, "column number out of range", 0);
+    return TCL_ERROR;
+  }
+  Tcl_AppendResult(interp, threadset[i].argv[n], 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: thread_colname  ID   N
+**
+** Wait on the most recent thread_step to complete, then return the
+** name of the N-th columns in the result set.
+*/
+static int tcl_thread_colname(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  int n;
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID N", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
+  thread_wait(&threadset[i]);
+  if( n<0 || n>=threadset[i].argc ){
+    Tcl_AppendResult(interp, "column number out of range", 0);
+    return TCL_ERROR;
+  }
+  Tcl_AppendResult(interp, threadset[i].colv[n], 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: thread_result  ID
+**
+** Wait on the most recent operation to complete, then return the
+** result code from that operation.
+*/
+static int tcl_thread_result(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  const char *zName;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  thread_wait(&threadset[i]);
+  switch( threadset[i].rc ){
+    case SQLITE_OK:         zName = "SQLITE_OK";          break;
+    case SQLITE_ERROR:      zName = "SQLITE_ERROR";       break;
+    case SQLITE_PERM:       zName = "SQLITE_PERM";        break;
+    case SQLITE_ABORT:      zName = "SQLITE_ABORT";       break;
+    case SQLITE_BUSY:       zName = "SQLITE_BUSY";        break;
+    case SQLITE_LOCKED:     zName = "SQLITE_LOCKED";      break;
+    case SQLITE_NOMEM:      zName = "SQLITE_NOMEM";       break;
+    case SQLITE_READONLY:   zName = "SQLITE_READONLY";    break;
+    case SQLITE_INTERRUPT:  zName = "SQLITE_INTERRUPT";   break;
+    case SQLITE_IOERR:      zName = "SQLITE_IOERR";       break;
+    case SQLITE_CORRUPT:    zName = "SQLITE_CORRUPT";     break;
+    case SQLITE_FULL:       zName = "SQLITE_FULL";        break;
+    case SQLITE_CANTOPEN:   zName = "SQLITE_CANTOPEN";    break;
+    case SQLITE_PROTOCOL:   zName = "SQLITE_PROTOCOL";    break;
+    case SQLITE_EMPTY:      zName = "SQLITE_EMPTY";       break;
+    case SQLITE_SCHEMA:     zName = "SQLITE_SCHEMA";      break;
+    case SQLITE_CONSTRAINT: zName = "SQLITE_CONSTRAINT";  break;
+    case SQLITE_MISMATCH:   zName = "SQLITE_MISMATCH";    break;
+    case SQLITE_MISUSE:     zName = "SQLITE_MISUSE";      break;
+    case SQLITE_NOLFS:      zName = "SQLITE_NOLFS";       break;
+    case SQLITE_AUTH:       zName = "SQLITE_AUTH";        break;
+    case SQLITE_FORMAT:     zName = "SQLITE_FORMAT";      break;
+    case SQLITE_RANGE:      zName = "SQLITE_RANGE";       break;
+    case SQLITE_ROW:        zName = "SQLITE_ROW";         break;
+    case SQLITE_DONE:       zName = "SQLITE_DONE";        break;
+    default:                zName = "SQLITE_Unknown";     break;
+  }
+  Tcl_AppendResult(interp, zName, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: thread_error  ID
+**
+** Wait on the most recent operation to complete, then return the
+** error string.
+*/
+static int tcl_thread_error(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  thread_wait(&threadset[i]);
+  Tcl_AppendResult(interp, threadset[i].zErr, 0);
+  return TCL_OK;
+}
+
+/*
+** This procedure runs in the thread to compile an SQL statement.
+*/
+static void do_compile(Thread *p){
+  if( p->db==0 ){
+    p->zErr = p->zStaticErr = "no database is open";
+    p->rc = SQLITE_ERROR;
+    return;
+  }
+  if( p->pStmt ){
+    sqlite3_finalize(p->pStmt);
+    p->pStmt = 0;
+  }
+  p->rc = sqlite3_prepare(p->db, p->zArg, -1, &p->pStmt, 0);
+}
+
+/*
+** Usage: thread_compile ID SQL
+**
+** Compile a new virtual machine.
+*/
+static int tcl_thread_compile(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID SQL", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  thread_wait(&threadset[i]);
+  threadset[i].xOp = do_compile;
+  sqlite3_free(threadset[i].zArg);
+  threadset[i].zArg = sqlite3DbStrDup(0, argv[2]);
+  threadset[i].opnum++;
+  return TCL_OK;
+}
+
+/*
+** This procedure runs in the thread to step the virtual machine.
+*/
+static void do_step(Thread *p){
+  int i;
+  if( p->pStmt==0 ){
+    p->zErr = p->zStaticErr = "no virtual machine available";
+    p->rc = SQLITE_ERROR;
+    return;
+  }
+  p->rc = sqlite3_step(p->pStmt);
+  if( p->rc==SQLITE_ROW ){
+    p->argc = sqlite3_column_count(p->pStmt);
+    for(i=0; i<sqlite3_data_count(p->pStmt); i++){
+      p->argv[i] = (char*)sqlite3_column_text(p->pStmt, i);
+    }
+    for(i=0; i<p->argc; i++){
+      p->colv[i] = sqlite3_column_name(p->pStmt, i);
+    }
+  }
+}
+
+/*
+** Usage: thread_step ID
+**
+** Advance the virtual machine by one step
+*/
+static int tcl_thread_step(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " IDL", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  thread_wait(&threadset[i]);
+  threadset[i].xOp = do_step;
+  threadset[i].opnum++;
+  return TCL_OK;
+}
+
+/*
+** This procedure runs in the thread to finalize a virtual machine.
+*/
+static void do_finalize(Thread *p){
+  if( p->pStmt==0 ){
+    p->zErr = p->zStaticErr = "no virtual machine available";
+    p->rc = SQLITE_ERROR;
+    return;
+  }
+  p->rc = sqlite3_finalize(p->pStmt);
+  p->pStmt = 0;
+}
+
+/*
+** Usage: thread_finalize ID
+**
+** Finalize the virtual machine.
+*/
+static int tcl_thread_finalize(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " IDL", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  thread_wait(&threadset[i]);
+  threadset[i].xOp = do_finalize;
+  sqlite3_free(threadset[i].zArg);
+  threadset[i].zArg = 0;
+  threadset[i].opnum++;
+  return TCL_OK;
+}
+
+/*
+** Usage: thread_swap ID ID
+**
+** Interchange the sqlite* pointer between two threads.
+*/
+static int tcl_thread_swap(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i, j;
+  sqlite3 *temp;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID1 ID2", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  thread_wait(&threadset[i]);
+  j = parse_thread_id(interp, argv[2]);
+  if( j<0 ) return TCL_ERROR;
+  if( !threadset[j].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  thread_wait(&threadset[j]);
+  temp = threadset[i].db;
+  threadset[i].db = threadset[j].db;
+  threadset[j].db = temp;
+  return TCL_OK;
+}
+
+/*
+** Usage: thread_db_get ID
+**
+** Return the database connection pointer for the given thread.  Then
+** remove the pointer from the thread itself.  Afterwards, the thread
+** can be stopped and the connection can be used by the main thread.
+*/
+static int tcl_thread_db_get(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  char zBuf[100];
+  extern int sqlite3TestMakePointerStr(Tcl_Interp*, char*, void*);
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  thread_wait(&threadset[i]);
+  sqlite3TestMakePointerStr(interp, zBuf, threadset[i].db);
+  threadset[i].db = 0;
+  Tcl_AppendResult(interp, zBuf, (char*)0);
+  return TCL_OK;
+}
+
+/*
+** Usage: thread_stmt_get ID
+**
+** Return the database stmt pointer for the given thread.  Then
+** remove the pointer from the thread itself. 
+*/
+static int tcl_thread_stmt_get(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  char zBuf[100];
+  extern int sqlite3TestMakePointerStr(Tcl_Interp*, char*, void*);
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_thread_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  thread_wait(&threadset[i]);
+  sqlite3TestMakePointerStr(interp, zBuf, threadset[i].pStmt);
+  threadset[i].pStmt = 0;
+  Tcl_AppendResult(interp, zBuf, (char*)0);
+  return TCL_OK;
+}
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest4_Init(Tcl_Interp *interp){
+  static struct {
+     char *zName;
+     Tcl_CmdProc *xProc;
+  } aCmd[] = {
+     { "thread_create",     (Tcl_CmdProc*)tcl_thread_create     },
+     { "thread_wait",       (Tcl_CmdProc*)tcl_thread_wait       },
+     { "thread_halt",       (Tcl_CmdProc*)tcl_thread_halt       },
+     { "thread_argc",       (Tcl_CmdProc*)tcl_thread_argc       },
+     { "thread_argv",       (Tcl_CmdProc*)tcl_thread_argv       },
+     { "thread_colname",    (Tcl_CmdProc*)tcl_thread_colname    },
+     { "thread_result",     (Tcl_CmdProc*)tcl_thread_result     },
+     { "thread_error",      (Tcl_CmdProc*)tcl_thread_error      },
+     { "thread_compile",    (Tcl_CmdProc*)tcl_thread_compile    },
+     { "thread_step",       (Tcl_CmdProc*)tcl_thread_step       },
+     { "thread_finalize",   (Tcl_CmdProc*)tcl_thread_finalize   },
+     { "thread_swap",       (Tcl_CmdProc*)tcl_thread_swap       },
+     { "thread_db_get",     (Tcl_CmdProc*)tcl_thread_db_get     },
+     { "thread_stmt_get",   (Tcl_CmdProc*)tcl_thread_stmt_get   },
+  };
+  int i;
+
+  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
+    Tcl_CreateCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
+  }
+  return TCL_OK;
+}
+#else
+int Sqlitetest4_Init(Tcl_Interp *interp){ return TCL_OK; }
+#endif /* SQLITE_OS_UNIX */
diff --git a/third_party/sqlite/src/test5.c b/third_party/sqlite/src/test5.c
new file mode 100755
index 0000000..cbb8840
--- /dev/null
+++ b/third_party/sqlite/src/test5.c
@@ -0,0 +1,217 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing the utf.c module in SQLite.  This code
+** is not included in the SQLite library.  It is used for automated
+** testing of the SQLite library. Specifically, the code in this file
+** is used for testing the SQLite routines for converting between
+** the various supported unicode encodings.
+**
+** $Id: test5.c,v 1.21 2008/07/28 19:34:54 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "vdbeInt.h"
+#include "tcl.h"
+#include <stdlib.h>
+#include <string.h>
+
+/*
+** The first argument is a TCL UTF-8 string. Return the byte array
+** object with the encoded representation of the string, including
+** the NULL terminator.
+*/
+static int binarize(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int len;
+  char *bytes;
+  Tcl_Obj *pRet;
+  assert(objc==2);
+
+  bytes = Tcl_GetStringFromObj(objv[1], &len);
+  pRet = Tcl_NewByteArrayObj((u8*)bytes, len+1);
+  Tcl_SetObjResult(interp, pRet);
+  return TCL_OK;
+}
+
+/*
+** Usage: test_value_overhead <repeat-count> <do-calls>.
+**
+** This routine is used to test the overhead of calls to
+** sqlite3_value_text(), on a value that contains a UTF-8 string. The idea
+** is to figure out whether or not it is a problem to use sqlite3_value
+** structures with collation sequence functions.
+**
+** If <do-calls> is 0, then the calls to sqlite3_value_text() are not
+** actually made.
+*/
+static int test_value_overhead(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int do_calls;
+  int repeat_count;
+  int i;
+  Mem val;
+  const char *zVal;
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " <repeat-count> <do-calls>", 0);
+    return TCL_ERROR;
+  }
+
+  if( Tcl_GetIntFromObj(interp, objv[1], &repeat_count) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &do_calls) ) return TCL_ERROR;
+
+  val.flags = MEM_Str|MEM_Term|MEM_Static;
+  val.z = "hello world";
+  val.type = SQLITE_TEXT;
+  val.enc = SQLITE_UTF8;
+
+  for(i=0; i<repeat_count; i++){
+    if( do_calls ){
+      zVal = (char*)sqlite3_value_text(&val);
+    }
+  }
+
+  return TCL_OK;
+}
+
+static u8 name_to_enc(Tcl_Interp *interp, Tcl_Obj *pObj){
+  struct EncName {
+    char *zName;
+    u8 enc;
+  } encnames[] = {
+    { "UTF8", SQLITE_UTF8 },
+    { "UTF16LE", SQLITE_UTF16LE },
+    { "UTF16BE", SQLITE_UTF16BE },
+    { "UTF16", SQLITE_UTF16NATIVE },
+    { 0, 0 }
+  };
+  struct EncName *pEnc;
+  char *z = Tcl_GetString(pObj);
+  for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
+    if( 0==sqlite3StrICmp(z, pEnc->zName) ){
+      break;
+    }
+  }
+  if( !pEnc->enc ){
+    Tcl_AppendResult(interp, "No such encoding: ", z, 0);
+  }
+  return pEnc->enc;
+}
+
+/*
+** Usage:   test_translate <string/blob> <from enc> <to enc> ?<transient>?
+**
+*/
+static int test_translate(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  u8 enc_from;
+  u8 enc_to;
+  sqlite3_value *pVal;
+
+  char *z;
+  int len;
+  void (*xDel)(void *p) = SQLITE_STATIC;
+
+  if( objc!=4 && objc!=5 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), 
+        " <string/blob> <from enc> <to enc>", 0
+    );
+    return TCL_ERROR;
+  }
+  if( objc==5 ){
+    xDel = sqlite3_free;
+  }
+
+  enc_from = name_to_enc(interp, objv[2]);
+  if( !enc_from ) return TCL_ERROR;
+  enc_to = name_to_enc(interp, objv[3]);
+  if( !enc_to ) return TCL_ERROR;
+
+  pVal = sqlite3ValueNew(0);
+
+  if( enc_from==SQLITE_UTF8 ){
+    z = Tcl_GetString(objv[1]);
+    if( objc==5 ){
+      z = sqlite3DbStrDup(0, z);
+    }
+    sqlite3ValueSetStr(pVal, -1, z, enc_from, xDel);
+  }else{
+    z = (char*)Tcl_GetByteArrayFromObj(objv[1], &len);
+    if( objc==5 ){
+      char *zTmp = z;
+      z = sqlite3_malloc(len);
+      memcpy(z, zTmp, len);
+    }
+    sqlite3ValueSetStr(pVal, -1, z, enc_from, xDel);
+  }
+
+  z = (char *)sqlite3ValueText(pVal, enc_to);
+  len = sqlite3ValueBytes(pVal, enc_to) + (enc_to==SQLITE_UTF8?1:2);
+  Tcl_SetObjResult(interp, Tcl_NewByteArrayObj((u8*)z, len));
+
+  sqlite3ValueFree(pVal);
+
+  return TCL_OK;
+}
+
+/*
+** Usage: translate_selftest
+**
+** Call sqlite3UtfSelfTest() to run the internal tests for unicode
+** translation. If there is a problem an assert() will fail.
+**/
+void sqlite3UtfSelfTest();
+static int test_translate_selftest(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifndef SQLITE_OMIT_UTF16
+  sqlite3UtfSelfTest();
+#endif
+  return SQLITE_OK;
+}
+
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest5_Init(Tcl_Interp *interp){
+  static struct {
+    char *zName;
+    Tcl_ObjCmdProc *xProc;
+  } aCmd[] = {
+    { "binarize",                (Tcl_ObjCmdProc*)binarize },
+    { "test_value_overhead",     (Tcl_ObjCmdProc*)test_value_overhead },
+    { "test_translate",          (Tcl_ObjCmdProc*)test_translate     },
+    { "translate_selftest",      (Tcl_ObjCmdProc*)test_translate_selftest},
+  };
+  int i;
+  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
+    Tcl_CreateObjCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
+  }
+  return SQLITE_OK;
+}
diff --git a/third_party/sqlite/src/test6.c b/third_party/sqlite/src/test6.c
new file mode 100755
index 0000000..8805cb8
--- /dev/null
+++ b/third_party/sqlite/src/test6.c
@@ -0,0 +1,881 @@
+/*
+** 2004 May 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code that modified the OS layer in order to simulate
+** the effect on the database file of an OS crash or power failure.  This
+** is used to test the ability of SQLite to recover from those situations.
+**
+** $Id: test6.c,v 1.39 2008/06/06 11:11:26 danielk1977 Exp $
+*/
+#if SQLITE_TEST          /* This file is used for testing only */
+#include "sqliteInt.h"
+#include "tcl.h"
+
+#ifndef SQLITE_OMIT_DISKIO  /* This file is a no-op if disk I/O is disabled */
+
+/* #define TRACE_CRASHTEST */
+
+typedef struct CrashFile CrashFile;
+typedef struct CrashGlobal CrashGlobal;
+typedef struct WriteBuffer WriteBuffer;
+
+/*
+** Method:
+**
+**   This layer is implemented as a wrapper around the "real" 
+**   sqlite3_file object for the host system. Each time data is 
+**   written to the file object, instead of being written to the
+**   underlying file, the write operation is stored in an in-memory 
+**   structure (type WriteBuffer). This structure is placed at the
+**   end of a global ordered list (the write-list).
+**
+**   When data is read from a file object, the requested region is
+**   first retrieved from the real file. The write-list is then 
+**   traversed and data copied from any overlapping WriteBuffer 
+**   structures to the output buffer. i.e. a read() operation following
+**   one or more write() operations works as expected, even if no
+**   data has actually been written out to the real file.
+**
+**   When a fsync() operation is performed, an operating system crash 
+**   may be simulated, in which case exit(-1) is called (the call to 
+**   xSync() never returns). Whether or not a crash is simulated,
+**   the data associated with a subset of the WriteBuffer structures 
+**   stored in the write-list is written to the real underlying files 
+**   and the entries removed from the write-list. If a crash is simulated,
+**   a subset of the buffers may be corrupted before the data is written.
+**
+**   The exact subset of the write-list written and/or corrupted is
+**   determined by the simulated device characteristics and sector-size.
+**
+** "Normal" mode:
+**
+**   Normal mode is used when the simulated device has none of the
+**   SQLITE_IOCAP_XXX flags set.
+**
+**   In normal mode, if the fsync() is not a simulated crash, the 
+**   write-list is traversed from beginning to end. Each WriteBuffer
+**   structure associated with the file handle used to call xSync()
+**   is written to the real file and removed from the write-list.
+**
+**   If a crash is simulated, one of the following takes place for 
+**   each WriteBuffer in the write-list, regardless of which 
+**   file-handle it is associated with:
+**
+**     1. The buffer is correctly written to the file, just as if
+**        a crash were not being simulated.
+**
+**     2. Nothing is done.
+**
+**     3. Garbage data is written to all sectors of the file that 
+**        overlap the region specified by the WriteBuffer. Or garbage
+**        data is written to some contiguous section within the 
+**        overlapped sectors.
+**
+** Device Characteristic flag handling:
+**
+**   If the IOCAP_ATOMIC flag is set, then option (3) above is 
+**   never selected.
+**
+**   If the IOCAP_ATOMIC512 flag is set, and the WriteBuffer represents
+**   an aligned write() of an integer number of 512 byte regions, then
+**   option (3) above is never selected. Instead, each 512 byte region
+**   is either correctly written or left completely untouched. Similar
+**   logic governs the behaviour if any of the other ATOMICXXX flags
+**   is set.
+**
+**   If either the IOCAP_SAFEAPPEND or IOCAP_SEQUENTIAL flags are set
+**   and a crash is being simulated, then an entry of the write-list is
+**   selected at random. Everything in the list after the selected entry 
+**   is discarded before processing begins.
+**
+**   If IOCAP_SEQUENTIAL is set and a crash is being simulated, option 
+**   (1) is selected for all write-list entries except the last. If a 
+**   crash is not being simulated, then all entries in the write-list
+**   that occur before at least one write() on the file-handle specified
+**   as part of the xSync() are written to their associated real files.
+**
+**   If IOCAP_SAFEAPPEND is set and the first byte written by the write()
+**   operation is one byte past the current end of the file, then option
+**   (1) is always selected.
+*/
+
+/*
+** Each write operation in the write-list is represented by an instance
+** of the following structure.
+**
+** If zBuf is 0, then this structure represents a call to xTruncate(), 
+** not xWrite(). In that case, iOffset is the size that the file is
+** truncated to.
+*/
+struct WriteBuffer {
+  i64 iOffset;                 /* Byte offset of the start of this write() */
+  int nBuf;                    /* Number of bytes written */
+  u8 *zBuf;                    /* Pointer to copy of written data */
+  CrashFile *pFile;            /* File this write() applies to */
+
+  WriteBuffer *pNext;          /* Next in CrashGlobal.pWriteList */
+};
+
+struct CrashFile {
+  const sqlite3_io_methods *pMethod;   /* Must be first */
+  sqlite3_file *pRealFile;             /* Underlying "real" file handle */
+  char *zName;
+
+  /* Cache of the entire file. This is used to speed up OsRead() and 
+  ** OsFileSize() calls. Although both could be done by traversing the
+  ** write-list, in practice this is impractically slow.
+  */
+  int iSize;                           /* Size of file in bytes */
+  int nData;                           /* Size of buffer allocated at zData */
+  u8 *zData;                           /* Buffer containing file contents */
+};
+
+struct CrashGlobal {
+  WriteBuffer *pWriteList;     /* Head of write-list */
+  WriteBuffer *pWriteListEnd;  /* End of write-list */
+
+  int iSectorSize;             /* Value of simulated sector size */
+  int iDeviceCharacteristics;  /* Value of simulated device characteristics */
+
+  int iCrash;                  /* Crash on the iCrash'th call to xSync() */
+  char zCrashFile[500];        /* Crash during an xSync() on this file */ 
+};
+
+static CrashGlobal g = {0, 0, SQLITE_DEFAULT_SECTOR_SIZE, 0, 0};
+
+/*
+** Set this global variable to 1 to enable crash testing.
+*/
+static int sqlite3CrashTestEnable = 0;
+
+static void *crash_malloc(int nByte){
+  return (void *)Tcl_Alloc((size_t)nByte);
+}
+static void crash_free(void *p){
+  Tcl_Free(p);
+}
+static void *crash_realloc(void *p, int n){
+  return (void *)Tcl_Realloc(p, (size_t)n);
+}
+
+/*
+** Flush the write-list as if xSync() had been called on file handle
+** pFile. If isCrash is true, simulate a crash.
+*/
+static int writeListSync(CrashFile *pFile, int isCrash){
+  int rc = SQLITE_OK;
+  int iDc = g.iDeviceCharacteristics;
+
+  WriteBuffer *pWrite;
+  WriteBuffer **ppPtr;
+
+  /* If this is not a crash simulation, set pFinal to point to the 
+  ** last element of the write-list that is associated with file handle
+  ** pFile.
+  **
+  ** If this is a crash simulation, set pFinal to an arbitrarily selected
+  ** element of the write-list.
+  */
+  WriteBuffer *pFinal = 0;
+  if( !isCrash ){
+    for(pWrite=g.pWriteList; pWrite; pWrite=pWrite->pNext){
+      if( pWrite->pFile==pFile ){
+        pFinal = pWrite;
+      }
+    }
+  }else if( iDc&(SQLITE_IOCAP_SEQUENTIAL|SQLITE_IOCAP_SAFE_APPEND) ){
+    int nWrite = 0;
+    int iFinal;
+    for(pWrite=g.pWriteList; pWrite; pWrite=pWrite->pNext) nWrite++;
+    sqlite3_randomness(sizeof(int), &iFinal);
+    iFinal = ((iFinal<0)?-1*iFinal:iFinal)%nWrite;
+    for(pWrite=g.pWriteList; iFinal>0; pWrite=pWrite->pNext) iFinal--;
+    pFinal = pWrite;
+  }
+
+#ifdef TRACE_CRASHTEST
+  printf("Sync %s (is %s crash)\n", pFile->zName, (isCrash?"a":"not a"));
+#endif
+
+  ppPtr = &g.pWriteList;
+  for(pWrite=*ppPtr; rc==SQLITE_OK && pWrite; pWrite=*ppPtr){
+    sqlite3_file *pRealFile = pWrite->pFile->pRealFile;
+
+    /* (eAction==1)      -> write block out normally,
+    ** (eAction==2)      -> do nothing,
+    ** (eAction==3)      -> trash sectors.
+    */
+    int eAction = 0;
+    if( !isCrash ){
+      eAction = 2;
+      if( (pWrite->pFile==pFile || iDc&SQLITE_IOCAP_SEQUENTIAL) ){
+        eAction = 1;
+      }
+    }else{
+      char random;
+      sqlite3_randomness(1, &random);
+
+      /* Do not select option 3 (sector trashing) if the IOCAP_ATOMIC flag 
+      ** is set or this is an OsTruncate(), not an Oswrite().
+      */
+      if( (iDc&SQLITE_IOCAP_ATOMIC) || (pWrite->zBuf==0) ){
+        random &= 0x01;
+      }
+
+      /* If IOCAP_SEQUENTIAL is set and this is not the final entry
+      ** in the truncated write-list, always select option 1 (write
+      ** out correctly).
+      */
+      if( (iDc&SQLITE_IOCAP_SEQUENTIAL && pWrite!=pFinal) ){
+        random = 0;
+      }
+
+      /* If IOCAP_SAFE_APPEND is set and this OsWrite() operation is
+      ** an append (first byte of the written region is 1 byte past the
+      ** current EOF), always select option 1 (write out correctly).
+      */
+      if( iDc&SQLITE_IOCAP_SAFE_APPEND && pWrite->zBuf ){
+        i64 iSize;
+        sqlite3OsFileSize(pRealFile, &iSize);
+        if( iSize==pWrite->iOffset ){
+          random = 0;
+        }
+      }
+
+      if( (random&0x06)==0x06 ){
+        eAction = 3;
+      }else{
+        eAction = ((random&0x01)?2:1);
+      }
+    }
+
+    switch( eAction ){
+      case 1: {               /* Write out correctly */
+        if( pWrite->zBuf ){
+          rc = sqlite3OsWrite(
+              pRealFile, pWrite->zBuf, pWrite->nBuf, pWrite->iOffset
+          );
+        }else{
+          rc = sqlite3OsTruncate(pRealFile, pWrite->iOffset);
+        }
+        *ppPtr = pWrite->pNext;
+#ifdef TRACE_CRASHTEST
+        if( isCrash ){
+          printf("Writing %d bytes @ %d (%s)\n", 
+            pWrite->nBuf, (int)pWrite->iOffset, pWrite->pFile->zName
+          );
+        }
+#endif
+        crash_free(pWrite);
+        break;
+      }
+      case 2: {               /* Do nothing */
+        ppPtr = &pWrite->pNext;
+#ifdef TRACE_CRASHTEST
+        if( isCrash ){
+          printf("Omiting %d bytes @ %d (%s)\n", 
+            pWrite->nBuf, (int)pWrite->iOffset, pWrite->pFile->zName
+          );
+        }
+#endif
+        break;
+      }
+      case 3: {               /* Trash sectors */
+        u8 *zGarbage;
+        int iFirst = (pWrite->iOffset/g.iSectorSize);
+        int iLast = (pWrite->iOffset+pWrite->nBuf-1)/g.iSectorSize;
+
+        assert(pWrite->zBuf);
+
+#ifdef TRACE_CRASHTEST
+        printf("Trashing %d sectors @ sector %d (%s)\n", 
+            1+iLast-iFirst, iFirst, pWrite->pFile->zName
+        );
+#endif
+
+        zGarbage = crash_malloc(g.iSectorSize);
+        if( zGarbage ){
+          sqlite3_int64 i;
+          for(i=iFirst; rc==SQLITE_OK && i<=iLast; i++){
+            sqlite3_randomness(g.iSectorSize, zGarbage); 
+            rc = sqlite3OsWrite(
+              pRealFile, zGarbage, g.iSectorSize, i*g.iSectorSize
+            );
+          }
+          crash_free(zGarbage);
+        }else{
+          rc = SQLITE_NOMEM;
+        }
+
+        ppPtr = &pWrite->pNext;
+        break;
+      }
+
+      default:
+        assert(!"Cannot happen");
+    }
+
+    if( pWrite==pFinal ) break;
+  }
+
+  if( rc==SQLITE_OK && isCrash ){
+    exit(-1);
+  }
+
+  for(pWrite=g.pWriteList; pWrite && pWrite->pNext; pWrite=pWrite->pNext);
+  g.pWriteListEnd = pWrite;
+
+  return rc;
+}
+
+/*
+** Add an entry to the end of the write-list.
+*/
+static int writeListAppend(
+  sqlite3_file *pFile,
+  sqlite3_int64 iOffset,
+  const u8 *zBuf,
+  int nBuf
+){
+  WriteBuffer *pNew;
+
+  assert((zBuf && nBuf) || (!nBuf && !zBuf));
+
+  pNew = (WriteBuffer *)crash_malloc(sizeof(WriteBuffer) + nBuf);
+  if( pNew==0 ){
+    fprintf(stderr, "out of memory in the crash simulator\n");
+  }
+  memset(pNew, 0, sizeof(WriteBuffer)+nBuf);
+  pNew->iOffset = iOffset;
+  pNew->nBuf = nBuf;
+  pNew->pFile = (CrashFile *)pFile;
+  if( zBuf ){
+    pNew->zBuf = (u8 *)&pNew[1];
+    memcpy(pNew->zBuf, zBuf, nBuf);
+  }
+
+  if( g.pWriteList ){
+    assert(g.pWriteListEnd);
+    g.pWriteListEnd->pNext = pNew;
+  }else{
+    g.pWriteList = pNew;
+  }
+  g.pWriteListEnd = pNew;
+  
+  return SQLITE_OK;
+}
+
+/*
+** Close a crash-file.
+*/
+static int cfClose(sqlite3_file *pFile){
+  CrashFile *pCrash = (CrashFile *)pFile;
+  writeListSync(pCrash, 0);
+  sqlite3OsClose(pCrash->pRealFile);
+  return SQLITE_OK;
+}
+
+/*
+** Read data from a crash-file.
+*/
+static int cfRead(
+  sqlite3_file *pFile, 
+  void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  CrashFile *pCrash = (CrashFile *)pFile;
+
+  /* Check the file-size to see if this is a short-read */
+  if( pCrash->iSize<(iOfst+iAmt) ){
+    return SQLITE_IOERR_SHORT_READ;
+  }
+
+  memcpy(zBuf, &pCrash->zData[iOfst], iAmt);
+  return SQLITE_OK;
+}
+
+/*
+** Write data to a crash-file.
+*/
+static int cfWrite(
+  sqlite3_file *pFile, 
+  const void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  CrashFile *pCrash = (CrashFile *)pFile;
+  if( iAmt+iOfst>pCrash->iSize ){
+    pCrash->iSize = iAmt+iOfst;
+  }
+  while( pCrash->iSize>pCrash->nData ){
+    u8 *zNew;
+    int nNew = (pCrash->nData*2) + 4096;
+    zNew = crash_realloc(pCrash->zData, nNew);
+    if( !zNew ){
+      return SQLITE_NOMEM;
+    }
+    memset(&zNew[pCrash->nData], 0, nNew-pCrash->nData);
+    pCrash->nData = nNew;
+    pCrash->zData = zNew;
+  }
+  memcpy(&pCrash->zData[iOfst], zBuf, iAmt);
+  return writeListAppend(pFile, iOfst, zBuf, iAmt);
+}
+
+/*
+** Truncate a crash-file.
+*/
+static int cfTruncate(sqlite3_file *pFile, sqlite_int64 size){
+  CrashFile *pCrash = (CrashFile *)pFile;
+  assert(size>=0);
+  if( pCrash->iSize>size ){
+    pCrash->iSize = size;
+  }
+  return writeListAppend(pFile, size, 0, 0);
+}
+
+/*
+** Sync a crash-file.
+*/
+static int cfSync(sqlite3_file *pFile, int flags){
+  CrashFile *pCrash = (CrashFile *)pFile;
+  int isCrash = 0;
+
+  const char *zName = pCrash->zName;
+  const char *zCrashFile = g.zCrashFile;
+  int nName = strlen(zName);
+  int nCrashFile = strlen(zCrashFile);
+
+  if( nCrashFile>0 && zCrashFile[nCrashFile-1]=='*' ){
+    nCrashFile--;
+    if( nName>nCrashFile ) nName = nCrashFile;
+  }
+
+  if( nName==nCrashFile && 0==memcmp(zName, zCrashFile, nName) ){
+    if( (--g.iCrash)==0 ) isCrash = 1;
+  }
+
+  return writeListSync(pCrash, isCrash);
+}
+
+/*
+** Return the current file-size of the crash-file.
+*/
+static int cfFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
+  CrashFile *pCrash = (CrashFile *)pFile;
+  *pSize = (i64)pCrash->iSize;
+  return SQLITE_OK;
+}
+
+/*
+** Calls related to file-locks are passed on to the real file handle.
+*/
+static int cfLock(sqlite3_file *pFile, int eLock){
+  return sqlite3OsLock(((CrashFile *)pFile)->pRealFile, eLock);
+}
+static int cfUnlock(sqlite3_file *pFile, int eLock){
+  return sqlite3OsUnlock(((CrashFile *)pFile)->pRealFile, eLock);
+}
+static int cfCheckReservedLock(sqlite3_file *pFile, int *pResOut){
+  return sqlite3OsCheckReservedLock(((CrashFile *)pFile)->pRealFile, pResOut);
+}
+static int cfFileControl(sqlite3_file *pFile, int op, void *pArg){
+  return sqlite3OsFileControl(((CrashFile *)pFile)->pRealFile, op, pArg);
+}
+
+/*
+** The xSectorSize() and xDeviceCharacteristics() functions return
+** the global values configured by the [sqlite_crashparams] tcl
+*  interface.
+*/
+static int cfSectorSize(sqlite3_file *pFile){
+  return g.iSectorSize;
+}
+static int cfDeviceCharacteristics(sqlite3_file *pFile){
+  return g.iDeviceCharacteristics;
+}
+
+static const sqlite3_io_methods CrashFileVtab = {
+  1,                            /* iVersion */
+  cfClose,                      /* xClose */
+  cfRead,                       /* xRead */
+  cfWrite,                      /* xWrite */
+  cfTruncate,                   /* xTruncate */
+  cfSync,                       /* xSync */
+  cfFileSize,                   /* xFileSize */
+  cfLock,                       /* xLock */
+  cfUnlock,                     /* xUnlock */
+  cfCheckReservedLock,          /* xCheckReservedLock */
+  cfFileControl,                /* xFileControl */
+  cfSectorSize,                 /* xSectorSize */
+  cfDeviceCharacteristics       /* xDeviceCharacteristics */
+};
+
+/*
+** Application data for the crash VFS
+*/
+struct crashAppData {
+  sqlite3_vfs *pOrig;                   /* Wrapped vfs structure */
+};
+
+/*
+** Open a crash-file file handle.
+**
+** The caller will have allocated pVfs->szOsFile bytes of space
+** at pFile. This file uses this space for the CrashFile structure
+** and allocates space for the "real" file structure using 
+** sqlite3_malloc(). The assumption here is (pVfs->szOsFile) is
+** equal or greater than sizeof(CrashFile).
+*/
+static int cfOpen(
+  sqlite3_vfs *pCfVfs,
+  const char *zName,
+  sqlite3_file *pFile,
+  int flags,
+  int *pOutFlags
+){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
+  int rc;
+  CrashFile *pWrapper = (CrashFile *)pFile;
+  sqlite3_file *pReal = (sqlite3_file*)&pWrapper[1];
+
+  memset(pWrapper, 0, sizeof(CrashFile));
+  rc = sqlite3OsOpen(pVfs, zName, pReal, flags, pOutFlags);
+
+  if( rc==SQLITE_OK ){
+    i64 iSize;
+    pWrapper->pMethod = &CrashFileVtab;
+    pWrapper->zName = (char *)zName;
+    pWrapper->pRealFile = pReal;
+    rc = sqlite3OsFileSize(pReal, &iSize);
+    pWrapper->iSize = (int)iSize;
+  }
+  if( rc==SQLITE_OK ){
+    pWrapper->nData = (4096 + pWrapper->iSize);
+    pWrapper->zData = crash_malloc(pWrapper->nData);
+    if( pWrapper->zData ){
+      memset(pWrapper->zData, 0, pWrapper->nData);
+      rc = sqlite3OsRead(pReal, pWrapper->zData, pWrapper->iSize, 0); 
+    }else{
+      rc = SQLITE_NOMEM;
+    }
+  }
+  if( rc!=SQLITE_OK && pWrapper->pMethod ){
+    sqlite3OsClose(pFile);
+  }
+  return rc;
+}
+
+static int cfDelete(sqlite3_vfs *pCfVfs, const char *zPath, int dirSync){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
+  return pVfs->xDelete(pVfs, zPath, dirSync);
+}
+static int cfAccess(
+  sqlite3_vfs *pCfVfs, 
+  const char *zPath, 
+  int flags, 
+  int *pResOut
+){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
+  return pVfs->xAccess(pVfs, zPath, flags, pResOut);
+}
+static int cfFullPathname(
+  sqlite3_vfs *pCfVfs, 
+  const char *zPath, 
+  int nPathOut,
+  char *zPathOut
+){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
+  return pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut);
+}
+static void *cfDlOpen(sqlite3_vfs *pCfVfs, const char *zPath){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
+  return pVfs->xDlOpen(pVfs, zPath);
+}
+static void cfDlError(sqlite3_vfs *pCfVfs, int nByte, char *zErrMsg){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
+  pVfs->xDlError(pVfs, nByte, zErrMsg);
+}
+static void *cfDlSym(sqlite3_vfs *pCfVfs, void *pHandle, const char *zSymbol){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
+  return pVfs->xDlSym(pVfs, pHandle, zSymbol);
+}
+static void cfDlClose(sqlite3_vfs *pCfVfs, void *pHandle){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
+  pVfs->xDlClose(pVfs, pHandle);
+}
+static int cfRandomness(sqlite3_vfs *pCfVfs, int nByte, char *zBufOut){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
+  return pVfs->xRandomness(pVfs, nByte, zBufOut);
+}
+static int cfSleep(sqlite3_vfs *pCfVfs, int nMicro){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
+  return pVfs->xSleep(pVfs, nMicro);
+}
+static int cfCurrentTime(sqlite3_vfs *pCfVfs, double *pTimeOut){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
+  return pVfs->xCurrentTime(pVfs, pTimeOut);
+}
+
+static int processDevSymArgs(
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[],
+  int *piDeviceChar,
+  int *piSectorSize
+){
+  struct DeviceFlag {
+    char *zName;
+    int iValue;
+  } aFlag[] = {
+    { "atomic",      SQLITE_IOCAP_ATOMIC      },
+    { "atomic512",   SQLITE_IOCAP_ATOMIC512   },
+    { "atomic1k",    SQLITE_IOCAP_ATOMIC1K    },
+    { "atomic2k",    SQLITE_IOCAP_ATOMIC2K    },
+    { "atomic4k",    SQLITE_IOCAP_ATOMIC4K    },
+    { "atomic8k",    SQLITE_IOCAP_ATOMIC8K    },
+    { "atomic16k",   SQLITE_IOCAP_ATOMIC16K   },
+    { "atomic32k",   SQLITE_IOCAP_ATOMIC32K   },
+    { "atomic64k",   SQLITE_IOCAP_ATOMIC64K   },
+    { "sequential",  SQLITE_IOCAP_SEQUENTIAL  },
+    { "safe_append", SQLITE_IOCAP_SAFE_APPEND },
+    { 0, 0 }
+  };
+
+  int i;
+  int iDc = 0;
+  int iSectorSize = 0;
+  int setSectorsize = 0;
+  int setDeviceChar = 0;
+
+  for(i=0; i<objc; i+=2){
+    int nOpt;
+    char *zOpt = Tcl_GetStringFromObj(objv[i], &nOpt);
+
+    if( (nOpt>11 || nOpt<2 || strncmp("-sectorsize", zOpt, nOpt)) 
+     && (nOpt>16 || nOpt<2 || strncmp("-characteristics", zOpt, nOpt))
+    ){
+      Tcl_AppendResult(interp, 
+        "Bad option: \"", zOpt, 
+        "\" - must be \"-characteristics\" or \"-sectorsize\"", 0
+      );
+      return TCL_ERROR;
+    }
+    if( i==objc-1 ){
+      Tcl_AppendResult(interp, "Option requires an argument: \"", zOpt, "\"",0);
+      return TCL_ERROR;
+    }
+
+    if( zOpt[1]=='s' ){
+      if( Tcl_GetIntFromObj(interp, objv[i+1], &iSectorSize) ){
+        return TCL_ERROR;
+      }
+      setSectorsize = 1;
+    }else{
+      int j;
+      Tcl_Obj **apObj;
+      int nObj;
+      if( Tcl_ListObjGetElements(interp, objv[i+1], &nObj, &apObj) ){
+        return TCL_ERROR;
+      }
+      for(j=0; j<nObj; j++){
+        int rc;
+        int iChoice;
+        Tcl_Obj *pFlag = Tcl_DuplicateObj(apObj[j]);
+        Tcl_IncrRefCount(pFlag);
+        Tcl_UtfToLower(Tcl_GetString(pFlag));
+ 
+        rc = Tcl_GetIndexFromObjStruct(
+            interp, pFlag, aFlag, sizeof(aFlag[0]), "no such flag", 0, &iChoice
+        );
+        Tcl_DecrRefCount(pFlag);
+        if( rc ){
+          return TCL_ERROR;
+        }
+
+        iDc |= aFlag[iChoice].iValue;
+      }
+      setDeviceChar = 1;
+    }
+  }
+
+  if( setDeviceChar ){
+    *piDeviceChar = iDc;
+  }
+  if( setSectorsize ){
+    *piSectorSize = iSectorSize;
+  }
+
+  return TCL_OK;
+}
+
+/*
+** tclcmd:   sqlite_crash_enable ENABLE
+**
+** Parameter ENABLE must be a boolean value. If true, then the "crash"
+** vfs is added to the system. If false, it is removed.
+*/
+static int crashEnableCmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int isEnable;
+  static sqlite3_vfs crashVfs = {
+    1,                  /* iVersion */
+    0,                  /* szOsFile */
+    0,                  /* mxPathname */
+    0,                  /* pNext */
+    "crash",            /* zName */
+    0,                  /* pAppData */
+  
+    cfOpen,               /* xOpen */
+    cfDelete,             /* xDelete */
+    cfAccess,             /* xAccess */
+    cfFullPathname,       /* xFullPathname */
+    cfDlOpen,             /* xDlOpen */
+    cfDlError,            /* xDlError */
+    cfDlSym,              /* xDlSym */
+    cfDlClose,            /* xDlClose */
+    cfRandomness,         /* xRandomness */
+    cfSleep,              /* xSleep */
+    cfCurrentTime         /* xCurrentTime */
+  };
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "ENABLE");
+    return TCL_ERROR;
+  }
+
+  if( Tcl_GetBooleanFromObj(interp, objv[1], &isEnable) ){
+    return TCL_ERROR;
+  }
+
+  if( (isEnable && crashVfs.pAppData) || (!isEnable && !crashVfs.pAppData) ){
+    return TCL_OK;
+  }
+
+  if( crashVfs.pAppData==0 ){
+    sqlite3_vfs *pOriginalVfs = sqlite3_vfs_find(0);
+    crashVfs.mxPathname = pOriginalVfs->mxPathname;
+    crashVfs.pAppData = (void *)pOriginalVfs;
+    crashVfs.szOsFile = sizeof(CrashFile) + pOriginalVfs->szOsFile;
+    sqlite3_vfs_register(&crashVfs, 0);
+  }else{
+    crashVfs.pAppData = 0;
+    sqlite3_vfs_unregister(&crashVfs);
+  }
+
+  return TCL_OK;
+}
+
+/*
+** tclcmd:   sqlite_crashparams ?OPTIONS? DELAY CRASHFILE
+**
+** This procedure implements a TCL command that enables crash testing
+** in testfixture.  Once enabled, crash testing cannot be disabled.
+**
+** Available options are "-characteristics" and "-sectorsize". Both require
+** an argument. For -sectorsize, this is the simulated sector size in
+** bytes. For -characteristics, the argument must be a list of io-capability
+** flags to simulate. Valid flags are "atomic", "atomic512", "atomic1K",
+** "atomic2K", "atomic4K", "atomic8K", "atomic16K", "atomic32K", 
+** "atomic64K", "sequential" and "safe_append".
+**
+** Example:
+**
+**   sqlite_crashparams -sect 1024 -char {atomic sequential} ./test.db 1
+**
+*/
+static int crashParamsObjCmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int iDelay;
+  const char *zCrashFile;
+  int nCrashFile, iDc, iSectorSize;
+
+  iDc = -1;
+  iSectorSize = -1;
+
+  if( objc<3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "?OPTIONS? DELAY CRASHFILE");
+    goto error;
+  }
+
+  zCrashFile = Tcl_GetStringFromObj(objv[objc-1], &nCrashFile);
+  if( nCrashFile>=sizeof(g.zCrashFile) ){
+    Tcl_AppendResult(interp, "Filename is too long: \"", zCrashFile, "\"", 0);
+    goto error;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[objc-2], &iDelay) ){
+    goto error;
+  }
+
+  if( processDevSymArgs(interp, objc-3, &objv[1], &iDc, &iSectorSize) ){
+    return TCL_ERROR;
+  }
+
+  if( iDc>=0 ){
+    g.iDeviceCharacteristics = iDc;
+  }
+  if( iSectorSize>=0 ){
+    g.iSectorSize = iSectorSize;
+  }
+
+  g.iCrash = iDelay;
+  memcpy(g.zCrashFile, zCrashFile, nCrashFile+1);
+  sqlite3CrashTestEnable = 1;
+  return TCL_OK;
+
+error:
+  return TCL_ERROR;
+}
+
+static int devSymObjCmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  void devsym_register(int iDeviceChar, int iSectorSize);
+
+  int iDc = -1;
+  int iSectorSize = -1;
+
+  if( processDevSymArgs(interp, objc-1, &objv[1], &iDc, &iSectorSize) ){
+    return TCL_ERROR;
+  }
+  devsym_register(iDc, iSectorSize);
+
+  return TCL_OK;
+}
+
+#endif /* SQLITE_OMIT_DISKIO */
+
+/*
+** This procedure registers the TCL procedures defined in this file.
+*/
+int Sqlitetest6_Init(Tcl_Interp *interp){
+#ifndef SQLITE_OMIT_DISKIO
+  Tcl_CreateObjCommand(interp, "sqlite3_crash_enable", crashEnableCmd, 0, 0);
+  Tcl_CreateObjCommand(interp, "sqlite3_crashparams", crashParamsObjCmd, 0, 0);
+  Tcl_CreateObjCommand(interp, "sqlite3_simulate_device", devSymObjCmd, 0, 0);
+#endif
+  return TCL_OK;
+}
+
+#endif /* SQLITE_TEST */
diff --git a/third_party/sqlite/src/test7.c b/third_party/sqlite/src/test7.c
new file mode 100755
index 0000000..78754bf
--- /dev/null
+++ b/third_party/sqlite/src/test7.c
@@ -0,0 +1,723 @@
+/*
+** 2006 January 09
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing the client/server version of the SQLite library.
+** Derived from test4.c.
+**
+** $Id: test7.c,v 1.12 2008/07/28 19:34:54 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "tcl.h"
+
+/*
+** This test only works on UNIX with a SQLITE_THREADSAFE build that includes
+** the SQLITE_SERVER option.
+*/
+#if defined(SQLITE_SERVER) && !defined(SQLITE_OMIT_SHARED_CACHE) && \
+    defined(SQLITE_OS_UNIX) && OS_UNIX && SQLITE_THREADSAFE
+
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <sched.h>
+#include <ctype.h>
+
+/*
+** Interfaces defined in server.c
+*/
+int sqlite3_client_open(const char*, sqlite3**);
+int sqlite3_client_prepare(sqlite3*,const char*,int,
+                           sqlite3_stmt**,const char**);
+int sqlite3_client_step(sqlite3_stmt*);
+int sqlite3_client_reset(sqlite3_stmt*);
+int sqlite3_client_finalize(sqlite3_stmt*);
+int sqlite3_client_close(sqlite3*);
+int sqlite3_server_start(void);
+int sqlite3_server_stop(void);
+
+/*
+** Each thread is controlled by an instance of the following
+** structure.
+*/
+typedef struct Thread Thread;
+struct Thread {
+  /* The first group of fields are writable by the supervisor thread
+  ** and read-only to the client threads
+  */
+  char *zFilename;         /* Name of database file */
+  void (*xOp)(Thread*);    /* next operation to do */
+  char *zArg;              /* argument usable by xOp */
+  volatile int opnum;      /* Operation number */
+  volatile int busy;       /* True if this thread is in use */
+
+  /* The next group of fields are writable by the client threads 
+  ** but read-only to the superviser thread.
+  */
+  volatile int completed;  /* Number of operations completed */
+  sqlite3 *db;             /* Open database */
+  sqlite3_stmt *pStmt;     /* Pending operation */
+  char *zErr;              /* operation error */
+  char *zStaticErr;        /* Static error message */
+  int rc;                  /* operation return code */
+  int argc;                /* number of columns in result */
+  const char *argv[100];   /* result columns */
+  const char *colv[100];   /* result column names */
+};
+
+/*
+** There can be as many as 26 threads running at once.  Each is named
+** by a capital letter: A, B, C, ..., Y, Z.
+*/
+#define N_THREAD 26
+static Thread threadset[N_THREAD];
+
+/*
+** The main loop for a thread.  Threads use busy waiting. 
+*/
+static void *client_main(void *pArg){
+  Thread *p = (Thread*)pArg;
+  if( p->db ){
+    sqlite3_client_close(p->db);
+  }
+  sqlite3_client_open(p->zFilename, &p->db);
+  if( SQLITE_OK!=sqlite3_errcode(p->db) ){
+    p->zErr = strdup(sqlite3_errmsg(p->db));
+    sqlite3_client_close(p->db);
+    p->db = 0;
+  }
+  p->pStmt = 0;
+  p->completed = 1;
+  while( p->opnum<=p->completed ) sched_yield();
+  while( p->xOp ){
+    if( p->zErr && p->zErr!=p->zStaticErr ){
+      sqlite3_free(p->zErr);
+      p->zErr = 0;
+    }
+    (*p->xOp)(p);
+    p->completed++;
+    while( p->opnum<=p->completed ) sched_yield();
+  }
+  if( p->pStmt ){
+    sqlite3_client_finalize(p->pStmt);
+    p->pStmt = 0;
+  }
+  if( p->db ){
+    sqlite3_client_close(p->db);
+    p->db = 0;
+  }
+  if( p->zErr && p->zErr!=p->zStaticErr ){
+    sqlite3_free(p->zErr);
+    p->zErr = 0;
+  }
+  p->completed++;
+  sqlite3_thread_cleanup();
+  return 0;
+}
+
+/*
+** Get a thread ID which is an upper case letter.  Return the index.
+** If the argument is not a valid thread ID put an error message in
+** the interpreter and return -1.
+*/
+static int parse_client_id(Tcl_Interp *interp, const char *zArg){
+  if( zArg==0 || zArg[0]==0 || zArg[1]!=0 || !isupper((unsigned char)zArg[0]) ){
+    Tcl_AppendResult(interp, "thread ID must be an upper case letter", 0);
+    return -1;
+  }
+  return zArg[0] - 'A';
+}
+
+/*
+** Usage:    client_create NAME  FILENAME
+**
+** NAME should be an upper case letter.  Start the thread running with
+** an open connection to the given database.
+*/
+static int tcl_client_create(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  pthread_t x;
+  int rc;
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID FILENAME", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( threadset[i].busy ){
+    Tcl_AppendResult(interp, "thread ", argv[1], " is already running", 0);
+    return TCL_ERROR;
+  }
+  threadset[i].busy = 1;
+  sqlite3_free(threadset[i].zFilename);
+  threadset[i].zFilename = sqlite3DbStrDup(0, argv[2]);
+  threadset[i].opnum = 1;
+  threadset[i].completed = 0;
+  rc = pthread_create(&x, 0, client_main, &threadset[i]);
+  if( rc ){
+    Tcl_AppendResult(interp, "failed to create the thread", 0);
+    sqlite3_free(threadset[i].zFilename);
+    threadset[i].busy = 0;
+    return TCL_ERROR;
+  }
+  pthread_detach(x);
+  sqlite3_server_start();
+  return TCL_OK;
+}
+
+/*
+** Wait for a thread to reach its idle state.
+*/
+static void client_wait(Thread *p){
+  while( p->opnum>p->completed ) sched_yield();
+}
+
+/*
+** Usage:  client_wait ID
+**
+** Wait on thread ID to reach its idle state.
+*/
+static int tcl_client_wait(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  return TCL_OK;
+}
+
+/*
+** Stop a thread.
+*/
+static void stop_thread(Thread *p){
+  client_wait(p);
+  p->xOp = 0;
+  p->opnum++;
+  client_wait(p);
+  sqlite3_free(p->zArg);
+  p->zArg = 0;
+  sqlite3_free(p->zFilename);
+  p->zFilename = 0;
+  p->busy = 0;
+}
+
+/*
+** Usage:  client_halt ID
+**
+** Cause a client thread to shut itself down.  Wait for the shutdown to be
+** completed.  If ID is "*" then stop all client threads.
+*/
+static int tcl_client_halt(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  if( argv[1][0]=='*' && argv[1][1]==0 ){
+    for(i=0; i<N_THREAD; i++){
+      if( threadset[i].busy ){
+        stop_thread(&threadset[i]);
+      }
+    }
+  }else{
+    i = parse_client_id(interp, argv[1]);
+    if( i<0 ) return TCL_ERROR;
+    if( !threadset[i].busy ){
+      Tcl_AppendResult(interp, "no such thread", 0);
+      return TCL_ERROR;
+    }
+    stop_thread(&threadset[i]);
+  }
+
+  /* If no client threads are still running, also stop the server */
+  for(i=0; i<N_THREAD && threadset[i].busy==0; i++){}
+  if( i>=N_THREAD ){
+    sqlite3_server_stop();
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage: client_argc  ID
+**
+** Wait on the most recent client_step to complete, then return the
+** number of columns in the result set.
+*/
+static int tcl_client_argc(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  char zBuf[100];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  sprintf(zBuf, "%d", threadset[i].argc);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: client_argv  ID   N
+**
+** Wait on the most recent client_step to complete, then return the
+** value of the N-th columns in the result set.
+*/
+static int tcl_client_argv(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  int n;
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID N", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
+  client_wait(&threadset[i]);
+  if( n<0 || n>=threadset[i].argc ){
+    Tcl_AppendResult(interp, "column number out of range", 0);
+    return TCL_ERROR;
+  }
+  Tcl_AppendResult(interp, threadset[i].argv[n], 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: client_colname  ID   N
+**
+** Wait on the most recent client_step to complete, then return the
+** name of the N-th columns in the result set.
+*/
+static int tcl_client_colname(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  int n;
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID N", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
+  client_wait(&threadset[i]);
+  if( n<0 || n>=threadset[i].argc ){
+    Tcl_AppendResult(interp, "column number out of range", 0);
+    return TCL_ERROR;
+  }
+  Tcl_AppendResult(interp, threadset[i].colv[n], 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: client_result  ID
+**
+** Wait on the most recent operation to complete, then return the
+** result code from that operation.
+*/
+static int tcl_client_result(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  const char *zName;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  switch( threadset[i].rc ){
+    case SQLITE_OK:         zName = "SQLITE_OK";          break;
+    case SQLITE_ERROR:      zName = "SQLITE_ERROR";       break;
+    case SQLITE_PERM:       zName = "SQLITE_PERM";        break;
+    case SQLITE_ABORT:      zName = "SQLITE_ABORT";       break;
+    case SQLITE_BUSY:       zName = "SQLITE_BUSY";        break;
+    case SQLITE_LOCKED:     zName = "SQLITE_LOCKED";      break;
+    case SQLITE_NOMEM:      zName = "SQLITE_NOMEM";       break;
+    case SQLITE_READONLY:   zName = "SQLITE_READONLY";    break;
+    case SQLITE_INTERRUPT:  zName = "SQLITE_INTERRUPT";   break;
+    case SQLITE_IOERR:      zName = "SQLITE_IOERR";       break;
+    case SQLITE_CORRUPT:    zName = "SQLITE_CORRUPT";     break;
+    case SQLITE_FULL:       zName = "SQLITE_FULL";        break;
+    case SQLITE_CANTOPEN:   zName = "SQLITE_CANTOPEN";    break;
+    case SQLITE_PROTOCOL:   zName = "SQLITE_PROTOCOL";    break;
+    case SQLITE_EMPTY:      zName = "SQLITE_EMPTY";       break;
+    case SQLITE_SCHEMA:     zName = "SQLITE_SCHEMA";      break;
+    case SQLITE_CONSTRAINT: zName = "SQLITE_CONSTRAINT";  break;
+    case SQLITE_MISMATCH:   zName = "SQLITE_MISMATCH";    break;
+    case SQLITE_MISUSE:     zName = "SQLITE_MISUSE";      break;
+    case SQLITE_NOLFS:      zName = "SQLITE_NOLFS";       break;
+    case SQLITE_AUTH:       zName = "SQLITE_AUTH";        break;
+    case SQLITE_FORMAT:     zName = "SQLITE_FORMAT";      break;
+    case SQLITE_RANGE:      zName = "SQLITE_RANGE";       break;
+    case SQLITE_ROW:        zName = "SQLITE_ROW";         break;
+    case SQLITE_DONE:       zName = "SQLITE_DONE";        break;
+    default:                zName = "SQLITE_Unknown";     break;
+  }
+  Tcl_AppendResult(interp, zName, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: client_error  ID
+**
+** Wait on the most recent operation to complete, then return the
+** error string.
+*/
+static int tcl_client_error(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  Tcl_AppendResult(interp, threadset[i].zErr, 0);
+  return TCL_OK;
+}
+
+/*
+** This procedure runs in the thread to compile an SQL statement.
+*/
+static void do_compile(Thread *p){
+  if( p->db==0 ){
+    p->zErr = p->zStaticErr = "no database is open";
+    p->rc = SQLITE_ERROR;
+    return;
+  }
+  if( p->pStmt ){
+    sqlite3_client_finalize(p->pStmt);
+    p->pStmt = 0;
+  }
+  p->rc = sqlite3_client_prepare(p->db, p->zArg, -1, &p->pStmt, 0);
+}
+
+/*
+** Usage: client_compile ID SQL
+**
+** Compile a new virtual machine.
+*/
+static int tcl_client_compile(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID SQL", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  threadset[i].xOp = do_compile;
+  sqlite3_free(threadset[i].zArg);
+  threadset[i].zArg = sqlite3DbStrDup(0, argv[2]);
+  threadset[i].opnum++;
+  return TCL_OK;
+}
+
+/*
+** This procedure runs in the thread to step the virtual machine.
+*/
+static void do_step(Thread *p){
+  int i;
+  if( p->pStmt==0 ){
+    p->zErr = p->zStaticErr = "no virtual machine available";
+    p->rc = SQLITE_ERROR;
+    return;
+  }
+  p->rc = sqlite3_client_step(p->pStmt);
+  if( p->rc==SQLITE_ROW ){
+    p->argc = sqlite3_column_count(p->pStmt);
+    for(i=0; i<sqlite3_data_count(p->pStmt); i++){
+      p->argv[i] = (char*)sqlite3_column_text(p->pStmt, i);
+    }
+    for(i=0; i<p->argc; i++){
+      p->colv[i] = sqlite3_column_name(p->pStmt, i);
+    }
+  }
+}
+
+/*
+** Usage: client_step ID
+**
+** Advance the virtual machine by one step
+*/
+static int tcl_client_step(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " IDL", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  threadset[i].xOp = do_step;
+  threadset[i].opnum++;
+  return TCL_OK;
+}
+
+/*
+** This procedure runs in the thread to finalize a virtual machine.
+*/
+static void do_finalize(Thread *p){
+  if( p->pStmt==0 ){
+    p->zErr = p->zStaticErr = "no virtual machine available";
+    p->rc = SQLITE_ERROR;
+    return;
+  }
+  p->rc = sqlite3_client_finalize(p->pStmt);
+  p->pStmt = 0;
+}
+
+/*
+** Usage: client_finalize ID
+**
+** Finalize the virtual machine.
+*/
+static int tcl_client_finalize(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " IDL", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  threadset[i].xOp = do_finalize;
+  sqlite3_free(threadset[i].zArg);
+  threadset[i].zArg = 0;
+  threadset[i].opnum++;
+  return TCL_OK;
+}
+
+/*
+** This procedure runs in the thread to reset a virtual machine.
+*/
+static void do_reset(Thread *p){
+  if( p->pStmt==0 ){
+    p->zErr = p->zStaticErr = "no virtual machine available";
+    p->rc = SQLITE_ERROR;
+    return;
+  }
+  p->rc = sqlite3_client_reset(p->pStmt);
+  p->pStmt = 0;
+}
+
+/*
+** Usage: client_reset ID
+**
+** Finalize the virtual machine.
+*/
+static int tcl_client_reset(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " IDL", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  threadset[i].xOp = do_reset;
+  sqlite3_free(threadset[i].zArg);
+  threadset[i].zArg = 0;
+  threadset[i].opnum++;
+  return TCL_OK;
+}
+
+/*
+** Usage: client_swap ID ID
+**
+** Interchange the sqlite* pointer between two threads.
+*/
+static int tcl_client_swap(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i, j;
+  sqlite3 *temp;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID1 ID2", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  j = parse_client_id(interp, argv[2]);
+  if( j<0 ) return TCL_ERROR;
+  if( !threadset[j].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[j]);
+  temp = threadset[i].db;
+  threadset[i].db = threadset[j].db;
+  threadset[j].db = temp;
+  return TCL_OK;
+}
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest7_Init(Tcl_Interp *interp){
+  static struct {
+     char *zName;
+     Tcl_CmdProc *xProc;
+  } aCmd[] = {
+     { "client_create",     (Tcl_CmdProc*)tcl_client_create     },
+     { "client_wait",       (Tcl_CmdProc*)tcl_client_wait       },
+     { "client_halt",       (Tcl_CmdProc*)tcl_client_halt       },
+     { "client_argc",       (Tcl_CmdProc*)tcl_client_argc       },
+     { "client_argv",       (Tcl_CmdProc*)tcl_client_argv       },
+     { "client_colname",    (Tcl_CmdProc*)tcl_client_colname    },
+     { "client_result",     (Tcl_CmdProc*)tcl_client_result     },
+     { "client_error",      (Tcl_CmdProc*)tcl_client_error      },
+     { "client_compile",    (Tcl_CmdProc*)tcl_client_compile    },
+     { "client_step",       (Tcl_CmdProc*)tcl_client_step       },
+     { "client_reset",      (Tcl_CmdProc*)tcl_client_reset      },
+     { "client_finalize",   (Tcl_CmdProc*)tcl_client_finalize   },
+     { "client_swap",       (Tcl_CmdProc*)tcl_client_swap       },
+  };
+  int i;
+
+  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
+    Tcl_CreateCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
+  }
+  return TCL_OK;
+}
+#else
+int Sqlitetest7_Init(Tcl_Interp *interp){ return TCL_OK; }
+#endif /* SQLITE_OS_UNIX */
diff --git a/third_party/sqlite/src/test8.c b/third_party/sqlite/src/test8.c
new file mode 100755
index 0000000..c9b87b9
--- /dev/null
+++ b/third_party/sqlite/src/test8.c
@@ -0,0 +1,1344 @@
+/*
+** 2006 June 10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing the virtual table interfaces.  This code
+** is not included in the SQLite library.  It is used for automated
+** testing of the SQLite library.
+**
+** $Id: test8.c,v 1.72 2008/08/05 21:36:07 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "tcl.h"
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+typedef struct echo_vtab echo_vtab;
+typedef struct echo_cursor echo_cursor;
+
+/*
+** The test module defined in this file uses four global Tcl variables to
+** commicate with test-scripts:
+**
+**     $::echo_module
+**     $::echo_module_sync_fail
+**     $::echo_module_begin_fail
+**     $::echo_module_cost
+**
+** The variable ::echo_module is a list. Each time one of the following
+** methods is called, one or more elements are appended to the list.
+** This is used for automated testing of virtual table modules.
+**
+** The ::echo_module_sync_fail variable is set by test scripts and read
+** by code in this file. If it is set to the name of a real table in the
+** the database, then all xSync operations on echo virtual tables that
+** use the named table as a backing store will fail.
+*/
+
+/*
+** Errors can be provoked within the following echo virtual table methods:
+**
+**   xBestIndex   xOpen     xFilter   xNext   
+**   xColumn      xRowid    xUpdate   xSync   
+**   xBegin       xRename
+**
+** This is done by setting the global tcl variable:
+**
+**   echo_module_fail($method,$tbl)
+**
+** where $method is set to the name of the virtual table method to fail
+** (i.e. "xBestIndex") and $tbl is the name of the table being echoed (not
+** the name of the virtual table, the name of the underlying real table).
+*/
+
+/* 
+** An echo virtual-table object.
+**
+** echo.vtab.aIndex is an array of booleans. The nth entry is true if 
+** the nth column of the real table is the left-most column of an index
+** (implicit or otherwise). In other words, if SQLite can optimize
+** a query like "SELECT * FROM real_table WHERE col = ?".
+**
+** Member variable aCol[] contains copies of the column names of the real
+** table.
+*/
+struct echo_vtab {
+  sqlite3_vtab base;
+  Tcl_Interp *interp;     /* Tcl interpreter containing debug variables */
+  sqlite3 *db;            /* Database connection */
+
+  int isPattern;
+  int inTransaction;      /* True if within a transaction */
+  char *zThis;            /* Name of the echo table */
+  char *zTableName;       /* Name of the real table */
+  char *zLogName;         /* Name of the log table */
+  int nCol;               /* Number of columns in the real table */
+  int *aIndex;            /* Array of size nCol. True if column has an index */
+  char **aCol;            /* Array of size nCol. Column names */
+};
+
+/* An echo cursor object */
+struct echo_cursor {
+  sqlite3_vtab_cursor base;
+  sqlite3_stmt *pStmt;
+};
+
+static int simulateVtabError(echo_vtab *p, const char *zMethod){
+  const char *zErr;
+  char zVarname[128];
+  zVarname[127] = '\0';
+  sqlite3_snprintf(127, zVarname, 
+                   "echo_module_fail(%s,%s)", zMethod, p->zTableName);
+  zErr = Tcl_GetVar(p->interp, zVarname, TCL_GLOBAL_ONLY);
+  if( zErr ){
+    p->base.zErrMsg = sqlite3_mprintf("echo-vtab-error: %s", zErr);
+  }
+  return (zErr!=0);
+}
+
+/*
+** Convert an SQL-style quoted string into a normal string by removing
+** the quote characters.  The conversion is done in-place.  If the
+** input does not begin with a quote character, then this routine
+** is a no-op.
+**
+** Examples:
+**
+**     "abc"   becomes   abc
+**     'xyz'   becomes   xyz
+**     [pqr]   becomes   pqr
+**     `mno`   becomes   mno
+*/
+static void dequoteString(char *z){
+  int quote;
+  int i, j;
+  if( z==0 ) return;
+  quote = z[0];
+  switch( quote ){
+    case '\'':  break;
+    case '"':   break;
+    case '`':   break;                /* For MySQL compatibility */
+    case '[':   quote = ']';  break;  /* For MS SqlServer compatibility */
+    default:    return;
+  }
+  for(i=1, j=0; z[i]; i++){
+    if( z[i]==quote ){
+      if( z[i+1]==quote ){
+        z[j++] = quote;
+        i++;
+      }else{
+        z[j++] = 0;
+        break;
+      }
+    }else{
+      z[j++] = z[i];
+    }
+  }
+}
+
+/*
+** Retrieve the column names for the table named zTab via database
+** connection db. SQLITE_OK is returned on success, or an sqlite error
+** code otherwise.
+**
+** If successful, the number of columns is written to *pnCol. *paCol is
+** set to point at sqlite3_malloc()'d space containing the array of
+** nCol column names. The caller is responsible for calling sqlite3_free
+** on *paCol.
+*/
+static int getColumnNames(
+  sqlite3 *db, 
+  const char *zTab,
+  char ***paCol, 
+  int *pnCol
+){
+  char **aCol = 0;
+  char *zSql;
+  sqlite3_stmt *pStmt = 0;
+  int rc = SQLITE_OK;
+  int nCol = 0;
+
+  /* Prepare the statement "SELECT * FROM <tbl>". The column names
+  ** of the result set of the compiled SELECT will be the same as
+  ** the column names of table <tbl>.
+  */
+  zSql = sqlite3_mprintf("SELECT * FROM %Q", zTab);
+  if( !zSql ){
+    rc = SQLITE_NOMEM;
+    goto out;
+  }
+  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
+  sqlite3_free(zSql);
+
+  if( rc==SQLITE_OK ){
+    int ii;
+    int nBytes;
+    char *zSpace;
+    nCol = sqlite3_column_count(pStmt);
+
+    /* Figure out how much space to allocate for the array of column names 
+    ** (including space for the strings themselves). Then allocate it.
+    */
+    nBytes = sizeof(char *) * nCol;
+    for(ii=0; ii<nCol; ii++){
+      const char *zName = sqlite3_column_name(pStmt, ii);
+      if( !zName ){
+        rc = SQLITE_NOMEM;
+        goto out;
+      }
+      nBytes += strlen(zName)+1;
+    }
+    aCol = (char **)sqlite3MallocZero(nBytes);
+    if( !aCol ){
+      rc = SQLITE_NOMEM;
+      goto out;
+    }
+
+    /* Copy the column names into the allocated space and set up the
+    ** pointers in the aCol[] array.
+    */
+    zSpace = (char *)(&aCol[nCol]);
+    for(ii=0; ii<nCol; ii++){
+      aCol[ii] = zSpace;
+      zSpace += sprintf(zSpace, "%s", sqlite3_column_name(pStmt, ii));
+      zSpace++;
+    }
+    assert( (zSpace-nBytes)==(char *)aCol );
+  }
+
+  *paCol = aCol;
+  *pnCol = nCol;
+
+out:
+  sqlite3_finalize(pStmt);
+  return rc;
+}
+
+/*
+** Parameter zTab is the name of a table in database db with nCol 
+** columns. This function allocates an array of integers nCol in 
+** size and populates it according to any implicit or explicit 
+** indices on table zTab.
+**
+** If successful, SQLITE_OK is returned and *paIndex set to point 
+** at the allocated array. Otherwise, an error code is returned.
+**
+** See comments associated with the member variable aIndex above 
+** "struct echo_vtab" for details of the contents of the array.
+*/
+static int getIndexArray(
+  sqlite3 *db,             /* Database connection */
+  const char *zTab,        /* Name of table in database db */
+  int nCol,
+  int **paIndex
+){
+  sqlite3_stmt *pStmt = 0;
+  int *aIndex = 0;
+  int rc;
+  char *zSql;
+
+  /* Allocate space for the index array */
+  aIndex = (int *)sqlite3MallocZero(sizeof(int) * nCol);
+  if( !aIndex ){
+    rc = SQLITE_NOMEM;
+    goto get_index_array_out;
+  }
+
+  /* Compile an sqlite pragma to loop through all indices on table zTab */
+  zSql = sqlite3MPrintf(0, "PRAGMA index_list(%s)", zTab);
+  if( !zSql ){
+    rc = SQLITE_NOMEM;
+    goto get_index_array_out;
+  }
+  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
+  sqlite3_free(zSql);
+
+  /* For each index, figure out the left-most column and set the 
+  ** corresponding entry in aIndex[] to 1.
+  */
+  while( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
+    const char *zIdx = (const char *)sqlite3_column_text(pStmt, 1);
+    sqlite3_stmt *pStmt2 = 0;
+    zSql = sqlite3MPrintf(0, "PRAGMA index_info(%s)", zIdx);
+    if( !zSql ){
+      rc = SQLITE_NOMEM;
+      goto get_index_array_out;
+    }
+    rc = sqlite3_prepare(db, zSql, -1, &pStmt2, 0);
+    sqlite3_free(zSql);
+    if( pStmt2 && sqlite3_step(pStmt2)==SQLITE_ROW ){
+      int cid = sqlite3_column_int(pStmt2, 1);
+      assert( cid>=0 && cid<nCol );
+      aIndex[cid] = 1;
+    }
+    if( pStmt2 ){
+      rc = sqlite3_finalize(pStmt2);
+    }
+    if( rc!=SQLITE_OK ){
+      goto get_index_array_out;
+    }
+  }
+
+
+get_index_array_out:
+  if( pStmt ){
+    int rc2 = sqlite3_finalize(pStmt);
+    if( rc==SQLITE_OK ){
+      rc = rc2;
+    }
+  }
+  if( rc!=SQLITE_OK ){
+    sqlite3_free(aIndex);
+    aIndex = 0;
+  }
+  *paIndex = aIndex;
+  return rc;
+}
+
+/*
+** Global Tcl variable $echo_module is a list. This routine appends
+** the string element zArg to that list in interpreter interp.
+*/
+static void appendToEchoModule(Tcl_Interp *interp, const char *zArg){
+  int flags = (TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
+  Tcl_SetVar(interp, "echo_module", (zArg?zArg:""), flags);
+}
+
+/*
+** This function is called from within the echo-modules xCreate and
+** xConnect methods. The argc and argv arguments are copies of those 
+** passed to the calling method. This function is responsible for
+** calling sqlite3_declare_vtab() to declare the schema of the virtual
+** table being created or connected.
+**
+** If the constructor was passed just one argument, i.e.:
+**
+**   CREATE TABLE t1 AS echo(t2);
+**
+** Then t2 is assumed to be the name of a *real* database table. The
+** schema of the virtual table is declared by passing a copy of the 
+** CREATE TABLE statement for the real table to sqlite3_declare_vtab().
+** Hence, the virtual table should have exactly the same column names and 
+** types as the real table.
+*/
+static int echoDeclareVtab(
+  echo_vtab *pVtab, 
+  sqlite3 *db 
+){
+  int rc = SQLITE_OK;
+
+  if( pVtab->zTableName ){
+    sqlite3_stmt *pStmt = 0;
+    rc = sqlite3_prepare(db, 
+        "SELECT sql FROM sqlite_master WHERE type = 'table' AND name = ?",
+        -1, &pStmt, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_text(pStmt, 1, pVtab->zTableName, -1, 0);
+      if( sqlite3_step(pStmt)==SQLITE_ROW ){
+        int rc2;
+        const char *zCreateTable = (const char *)sqlite3_column_text(pStmt, 0);
+        rc = sqlite3_declare_vtab(db, zCreateTable);
+        rc2 = sqlite3_finalize(pStmt);
+        if( rc==SQLITE_OK ){
+          rc = rc2;
+        }
+      } else {
+        rc = sqlite3_finalize(pStmt);
+        if( rc==SQLITE_OK ){ 
+          rc = SQLITE_ERROR;
+        }
+      }
+      if( rc==SQLITE_OK ){
+        rc = getColumnNames(db, pVtab->zTableName, &pVtab->aCol, &pVtab->nCol);
+      }
+      if( rc==SQLITE_OK ){
+        rc = getIndexArray(db, pVtab->zTableName, pVtab->nCol, &pVtab->aIndex);
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** This function frees all runtime structures associated with the virtual
+** table pVtab.
+*/
+static int echoDestructor(sqlite3_vtab *pVtab){
+  echo_vtab *p = (echo_vtab*)pVtab;
+  sqlite3_free(p->aIndex);
+  sqlite3_free(p->aCol);
+  sqlite3_free(p->zThis);
+  sqlite3_free(p->zTableName);
+  sqlite3_free(p->zLogName);
+  sqlite3_free(p);
+  return 0;
+}
+
+typedef struct EchoModule EchoModule;
+struct EchoModule {
+  Tcl_Interp *interp;
+};
+
+/*
+** This function is called to do the work of the xConnect() method -
+** to allocate the required in-memory structures for a newly connected
+** virtual table.
+*/
+static int echoConstructor(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  int rc;
+  int i;
+  echo_vtab *pVtab;
+
+  /* Allocate the sqlite3_vtab/echo_vtab structure itself */
+  pVtab = sqlite3MallocZero( sizeof(*pVtab) );
+  if( !pVtab ){
+    return SQLITE_NOMEM;
+  }
+  pVtab->interp = ((EchoModule *)pAux)->interp;
+  pVtab->db = db;
+
+  /* Allocate echo_vtab.zThis */
+  pVtab->zThis = sqlite3MPrintf(0, "%s", argv[2]);
+  if( !pVtab->zThis ){
+    echoDestructor((sqlite3_vtab *)pVtab);
+    return SQLITE_NOMEM;
+  }
+
+  /* Allocate echo_vtab.zTableName */
+  if( argc>3 ){
+    pVtab->zTableName = sqlite3MPrintf(0, "%s", argv[3]);
+    dequoteString(pVtab->zTableName);
+    if( pVtab->zTableName && pVtab->zTableName[0]=='*' ){
+      char *z = sqlite3MPrintf(0, "%s%s", argv[2], &(pVtab->zTableName[1]));
+      sqlite3_free(pVtab->zTableName);
+      pVtab->zTableName = z;
+      pVtab->isPattern = 1;
+    }
+    if( !pVtab->zTableName ){
+      echoDestructor((sqlite3_vtab *)pVtab);
+      return SQLITE_NOMEM;
+    }
+  }
+
+  /* Log the arguments to this function to Tcl var ::echo_module */
+  for(i=0; i<argc; i++){
+    appendToEchoModule(pVtab->interp, argv[i]);
+  }
+
+  /* Invoke sqlite3_declare_vtab and set up other members of the echo_vtab
+  ** structure. If an error occurs, delete the sqlite3_vtab structure and
+  ** return an error code.
+  */
+  rc = echoDeclareVtab(pVtab, db);
+  if( rc!=SQLITE_OK ){
+    echoDestructor((sqlite3_vtab *)pVtab);
+    return rc;
+  }
+
+  /* Success. Set *ppVtab and return */
+  *ppVtab = &pVtab->base;
+  return SQLITE_OK;
+}
+
+/* 
+** Echo virtual table module xCreate method.
+*/
+static int echoCreate(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  int rc = SQLITE_OK;
+  appendToEchoModule(((EchoModule *)pAux)->interp, "xCreate");
+  rc = echoConstructor(db, pAux, argc, argv, ppVtab, pzErr);
+
+  /* If there were two arguments passed to the module at the SQL level 
+  ** (i.e. "CREATE VIRTUAL TABLE tbl USING echo(arg1, arg2)"), then 
+  ** the second argument is used as a table name. Attempt to create
+  ** such a table with a single column, "logmsg". This table will
+  ** be used to log calls to the xUpdate method. It will be deleted
+  ** when the virtual table is DROPed.
+  **
+  ** Note: The main point of this is to test that we can drop tables
+  ** from within an xDestroy method call.
+  */
+  if( rc==SQLITE_OK && argc==5 ){
+    char *zSql;
+    echo_vtab *pVtab = *(echo_vtab **)ppVtab;
+    pVtab->zLogName = sqlite3MPrintf(0, "%s", argv[4]);
+    zSql = sqlite3MPrintf(0, "CREATE TABLE %Q(logmsg)", pVtab->zLogName);
+    rc = sqlite3_exec(db, zSql, 0, 0, 0);
+    sqlite3_free(zSql);
+    if( rc!=SQLITE_OK ){
+      *pzErr = sqlite3DbStrDup(0, sqlite3_errmsg(db));
+    }
+  }
+
+  if( *ppVtab && rc!=SQLITE_OK ){
+    echoDestructor(*ppVtab);
+    *ppVtab = 0;
+  }
+
+  if( rc==SQLITE_OK ){
+    (*(echo_vtab**)ppVtab)->inTransaction = 1;
+  }
+
+  return rc;
+}
+
+/* 
+** Echo virtual table module xConnect method.
+*/
+static int echoConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  appendToEchoModule(((EchoModule *)pAux)->interp, "xConnect");
+  return echoConstructor(db, pAux, argc, argv, ppVtab, pzErr);
+}
+
+/* 
+** Echo virtual table module xDisconnect method.
+*/
+static int echoDisconnect(sqlite3_vtab *pVtab){
+  appendToEchoModule(((echo_vtab *)pVtab)->interp, "xDisconnect");
+  return echoDestructor(pVtab);
+}
+
+/* 
+** Echo virtual table module xDestroy method.
+*/
+static int echoDestroy(sqlite3_vtab *pVtab){
+  int rc = SQLITE_OK;
+  echo_vtab *p = (echo_vtab *)pVtab;
+  appendToEchoModule(((echo_vtab *)pVtab)->interp, "xDestroy");
+
+  /* Drop the "log" table, if one exists (see echoCreate() for details) */
+  if( p && p->zLogName ){
+    char *zSql;
+    zSql = sqlite3MPrintf(0, "DROP TABLE %Q", p->zLogName);
+    rc = sqlite3_exec(p->db, zSql, 0, 0, 0);
+    sqlite3_free(zSql);
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = echoDestructor(pVtab);
+  }
+  return rc;
+}
+
+/* 
+** Echo virtual table module xOpen method.
+*/
+static int echoOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  echo_cursor *pCur;
+  if( simulateVtabError((echo_vtab *)pVTab, "xOpen") ){
+    return SQLITE_ERROR;
+  }
+  pCur = sqlite3MallocZero(sizeof(echo_cursor));
+  *ppCursor = (sqlite3_vtab_cursor *)pCur;
+  return (pCur ? SQLITE_OK : SQLITE_NOMEM);
+}
+
+/* 
+** Echo virtual table module xClose method.
+*/
+static int echoClose(sqlite3_vtab_cursor *cur){
+  int rc;
+  echo_cursor *pCur = (echo_cursor *)cur;
+  sqlite3_stmt *pStmt = pCur->pStmt;
+  pCur->pStmt = 0;
+  sqlite3_free(pCur);
+  rc = sqlite3_finalize(pStmt);
+  return rc;
+}
+
+/*
+** Return non-zero if the cursor does not currently point to a valid record
+** (i.e if the scan has finished), or zero otherwise.
+*/
+static int echoEof(sqlite3_vtab_cursor *cur){
+  return (((echo_cursor *)cur)->pStmt ? 0 : 1);
+}
+
+/* 
+** Echo virtual table module xNext method.
+*/
+static int echoNext(sqlite3_vtab_cursor *cur){
+  int rc = SQLITE_OK;
+  echo_cursor *pCur = (echo_cursor *)cur;
+
+  if( simulateVtabError((echo_vtab *)(cur->pVtab), "xNext") ){
+    return SQLITE_ERROR;
+  }
+
+  if( pCur->pStmt ){
+    rc = sqlite3_step(pCur->pStmt);
+    if( rc==SQLITE_ROW ){
+      rc = SQLITE_OK;
+    }else{
+      rc = sqlite3_finalize(pCur->pStmt);
+      pCur->pStmt = 0;
+    }
+  }
+
+  return rc;
+}
+
+/* 
+** Echo virtual table module xColumn method.
+*/
+static int echoColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  int iCol = i + 1;
+  sqlite3_stmt *pStmt = ((echo_cursor *)cur)->pStmt;
+
+  if( simulateVtabError((echo_vtab *)(cur->pVtab), "xColumn") ){
+    return SQLITE_ERROR;
+  }
+
+  if( !pStmt ){
+    sqlite3_result_null(ctx);
+  }else{
+    assert( sqlite3_data_count(pStmt)>iCol );
+    sqlite3_result_value(ctx, sqlite3_column_value(pStmt, iCol));
+  }
+  return SQLITE_OK;
+}
+
+/* 
+** Echo virtual table module xRowid method.
+*/
+static int echoRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  sqlite3_stmt *pStmt = ((echo_cursor *)cur)->pStmt;
+
+  if( simulateVtabError((echo_vtab *)(cur->pVtab), "xRowid") ){
+    return SQLITE_ERROR;
+  }
+
+  *pRowid = sqlite3_column_int64(pStmt, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Compute a simple hash of the null terminated string zString.
+**
+** This module uses only sqlite3_index_info.idxStr, not 
+** sqlite3_index_info.idxNum. So to test idxNum, when idxStr is set
+** in echoBestIndex(), idxNum is set to the corresponding hash value.
+** In echoFilter(), code assert()s that the supplied idxNum value is
+** indeed the hash of the supplied idxStr.
+*/
+static int hashString(const char *zString){
+  int val = 0;
+  int ii;
+  for(ii=0; zString[ii]; ii++){
+    val = (val << 3) + (int)zString[ii];
+  }
+  return val;
+}
+
+/* 
+** Echo virtual table module xFilter method.
+*/
+static int echoFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  int rc;
+  int i;
+
+  echo_cursor *pCur = (echo_cursor *)pVtabCursor;
+  echo_vtab *pVtab = (echo_vtab *)pVtabCursor->pVtab;
+  sqlite3 *db = pVtab->db;
+
+  if( simulateVtabError(pVtab, "xFilter") ){
+    return SQLITE_ERROR;
+  }
+
+  /* Check that idxNum matches idxStr */
+  assert( idxNum==hashString(idxStr) );
+
+  /* Log arguments to the ::echo_module Tcl variable */
+  appendToEchoModule(pVtab->interp, "xFilter");
+  appendToEchoModule(pVtab->interp, idxStr);
+  for(i=0; i<argc; i++){
+    appendToEchoModule(pVtab->interp, (const char*)sqlite3_value_text(argv[i]));
+  }
+
+  sqlite3_finalize(pCur->pStmt);
+  pCur->pStmt = 0;
+
+  /* Prepare the SQL statement created by echoBestIndex and bind the
+  ** runtime parameters passed to this function to it.
+  */
+  rc = sqlite3_prepare(db, idxStr, -1, &pCur->pStmt, 0);
+  assert( pCur->pStmt || rc!=SQLITE_OK );
+  for(i=0; rc==SQLITE_OK && i<argc; i++){
+    sqlite3_bind_value(pCur->pStmt, i+1, argv[i]);
+  }
+
+  /* If everything was successful, advance to the first row of the scan */
+  if( rc==SQLITE_OK ){
+    rc = echoNext(pVtabCursor);
+  }
+
+  return rc;
+}
+
+
+/*
+** A helper function used by echoUpdate() and echoBestIndex() for
+** manipulating strings in concert with the sqlite3_mprintf() function.
+**
+** Parameter pzStr points to a pointer to a string allocated with
+** sqlite3_mprintf. The second parameter, zAppend, points to another
+** string. The two strings are concatenated together and *pzStr
+** set to point at the result. The initial buffer pointed to by *pzStr
+** is deallocated via sqlite3_free().
+**
+** If the third argument, doFree, is true, then sqlite3_free() is
+** also called to free the buffer pointed to by zAppend.
+*/
+static void string_concat(char **pzStr, char *zAppend, int doFree, int *pRc){
+  char *zIn = *pzStr;
+  if( !zAppend && doFree && *pRc==SQLITE_OK ){
+    *pRc = SQLITE_NOMEM;
+  }
+  if( *pRc!=SQLITE_OK ){
+    sqlite3_free(zIn);
+    zIn = 0;
+  }else{
+    if( zIn ){
+      char *zTemp = zIn;
+      zIn = sqlite3_mprintf("%s%s", zIn, zAppend);
+      sqlite3_free(zTemp);
+    }else{
+      zIn = sqlite3_mprintf("%s", zAppend);
+    }
+    if( !zIn ){
+      *pRc = SQLITE_NOMEM;
+    }
+  }
+  *pzStr = zIn;
+  if( doFree ){
+    sqlite3_free(zAppend);
+  }
+}
+
+/*
+** The echo module implements the subset of query constraints and sort
+** orders that may take advantage of SQLite indices on the underlying
+** real table. For example, if the real table is declared as:
+**
+**     CREATE TABLE real(a, b, c);
+**     CREATE INDEX real_index ON real(b);
+**
+** then the echo module handles WHERE or ORDER BY clauses that refer
+** to the column "b", but not "a" or "c". If a multi-column index is
+** present, only its left most column is considered. 
+**
+** This xBestIndex method encodes the proposed search strategy as
+** an SQL query on the real table underlying the virtual echo module 
+** table and stores the query in sqlite3_index_info.idxStr. The SQL
+** statement is of the form:
+**
+**   SELECT rowid, * FROM <real-table> ?<where-clause>? ?<order-by-clause>?
+**
+** where the <where-clause> and <order-by-clause> are determined
+** by the contents of the structure pointed to by the pIdxInfo argument.
+*/
+static int echoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  int ii;
+  char *zQuery = 0;
+  char *zNew;
+  int nArg = 0;
+  const char *zSep = "WHERE";
+  echo_vtab *pVtab = (echo_vtab *)tab;
+  sqlite3_stmt *pStmt = 0;
+  Tcl_Interp *interp = pVtab->interp;
+
+  int nRow;
+  int useIdx = 0;
+  int rc = SQLITE_OK;
+  int useCost = 0;
+  double cost;
+  int isIgnoreUsable = 0;
+  if( Tcl_GetVar(interp, "echo_module_ignore_usable", TCL_GLOBAL_ONLY) ){
+    isIgnoreUsable = 1;
+  }
+
+  if( simulateVtabError(pVtab, "xBestIndex") ){
+    return SQLITE_ERROR;
+  }
+
+  /* Determine the number of rows in the table and store this value in local
+  ** variable nRow. The 'estimated-cost' of the scan will be the number of
+  ** rows in the table for a linear scan, or the log (base 2) of the 
+  ** number of rows if the proposed scan uses an index.  
+  */
+  if( Tcl_GetVar(interp, "echo_module_cost", TCL_GLOBAL_ONLY) ){
+    cost = atof(Tcl_GetVar(interp, "echo_module_cost", TCL_GLOBAL_ONLY));
+    useCost = 1;
+  } else {
+    zQuery = sqlite3_mprintf("SELECT count(*) FROM %Q", pVtab->zTableName);
+    if( !zQuery ){
+      return SQLITE_NOMEM;
+    }
+    rc = sqlite3_prepare(pVtab->db, zQuery, -1, &pStmt, 0);
+    sqlite3_free(zQuery);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    sqlite3_step(pStmt);
+    nRow = sqlite3_column_int(pStmt, 0);
+    rc = sqlite3_finalize(pStmt);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+  }
+
+  zQuery = sqlite3_mprintf("SELECT rowid, * FROM %Q", pVtab->zTableName);
+  if( !zQuery ){
+    return SQLITE_NOMEM;
+  }
+  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
+    const struct sqlite3_index_constraint *pConstraint;
+    struct sqlite3_index_constraint_usage *pUsage;
+    int iCol;
+
+    pConstraint = &pIdxInfo->aConstraint[ii];
+    pUsage = &pIdxInfo->aConstraintUsage[ii];
+
+    if( !isIgnoreUsable && !pConstraint->usable ) continue;
+
+    iCol = pConstraint->iColumn;
+    if( pVtab->aIndex[iCol] || iCol<0 ){
+      char *zCol = pVtab->aCol[iCol];
+      char *zOp = 0;
+      useIdx = 1;
+      if( iCol<0 ){
+        zCol = "rowid";
+      }
+      switch( pConstraint->op ){
+        case SQLITE_INDEX_CONSTRAINT_EQ:
+          zOp = "="; break;
+        case SQLITE_INDEX_CONSTRAINT_LT:
+          zOp = "<"; break;
+        case SQLITE_INDEX_CONSTRAINT_GT:
+          zOp = ">"; break;
+        case SQLITE_INDEX_CONSTRAINT_LE:
+          zOp = "<="; break;
+        case SQLITE_INDEX_CONSTRAINT_GE:
+          zOp = ">="; break;
+        case SQLITE_INDEX_CONSTRAINT_MATCH:
+          zOp = "LIKE"; break;
+      }
+      if( zOp[0]=='L' ){
+        zNew = sqlite3_mprintf(" %s %s LIKE (SELECT '%%'||?||'%%')", 
+                               zSep, zCol);
+      } else {
+        zNew = sqlite3_mprintf(" %s %s %s ?", zSep, zCol, zOp);
+      }
+      string_concat(&zQuery, zNew, 1, &rc);
+
+      zSep = "AND";
+      pUsage->argvIndex = ++nArg;
+      pUsage->omit = 1;
+    }
+  }
+
+  /* If there is only one term in the ORDER BY clause, and it is
+  ** on a column that this virtual table has an index for, then consume 
+  ** the ORDER BY clause.
+  */
+  if( pIdxInfo->nOrderBy==1 && pVtab->aIndex[pIdxInfo->aOrderBy->iColumn] ){
+    int iCol = pIdxInfo->aOrderBy->iColumn;
+    char *zCol = pVtab->aCol[iCol];
+    char *zDir = pIdxInfo->aOrderBy->desc?"DESC":"ASC";
+    if( iCol<0 ){
+      zCol = "rowid";
+    }
+    zNew = sqlite3_mprintf(" ORDER BY %s %s", zCol, zDir);
+    string_concat(&zQuery, zNew, 1, &rc);
+    pIdxInfo->orderByConsumed = 1;
+  }
+
+  appendToEchoModule(pVtab->interp, "xBestIndex");;
+  appendToEchoModule(pVtab->interp, zQuery);
+
+  if( !zQuery ){
+    return rc;
+  }
+  pIdxInfo->idxNum = hashString(zQuery);
+  pIdxInfo->idxStr = zQuery;
+  pIdxInfo->needToFreeIdxStr = 1;
+  if (useCost) {
+    pIdxInfo->estimatedCost = cost;
+  } else if( useIdx ){
+    /* Approximation of log2(nRow). */
+    for( ii=0; ii<(sizeof(int)*8); ii++ ){
+      if( nRow & (1<<ii) ){
+        pIdxInfo->estimatedCost = (double)ii;
+      }
+    }
+  } else {
+    pIdxInfo->estimatedCost = (double)nRow;
+  }
+  return rc;
+}
+
+/*
+** The xUpdate method for echo module virtual tables.
+** 
+**    apData[0]  apData[1]  apData[2..]
+**
+**    INTEGER                              DELETE            
+**
+**    INTEGER    NULL       (nCol args)    UPDATE (do not set rowid)
+**    INTEGER    INTEGER    (nCol args)    UPDATE (with SET rowid = <arg1>)
+**
+**    NULL       NULL       (nCol args)    INSERT INTO (automatic rowid value)
+**    NULL       INTEGER    (nCol args)    INSERT (incl. rowid value)
+**
+*/
+int echoUpdate(
+  sqlite3_vtab *tab, 
+  int nData, 
+  sqlite3_value **apData, 
+  sqlite_int64 *pRowid
+){
+  echo_vtab *pVtab = (echo_vtab *)tab;
+  sqlite3 *db = pVtab->db;
+  int rc = SQLITE_OK;
+
+  sqlite3_stmt *pStmt;
+  char *z = 0;               /* SQL statement to execute */
+  int bindArgZero = 0;       /* True to bind apData[0] to sql var no. nData */
+  int bindArgOne = 0;        /* True to bind apData[1] to sql var no. 1 */
+  int i;                     /* Counter variable used by for loops */
+
+  assert( nData==pVtab->nCol+2 || nData==1 );
+
+  /* Ticket #3083 - make sure we always start a transaction prior to
+  ** making any changes to a virtual table */
+  assert( pVtab->inTransaction );
+
+  if( simulateVtabError(pVtab, "xUpdate") ){
+    return SQLITE_ERROR;
+  }
+
+  /* If apData[0] is an integer and nData>1 then do an UPDATE */
+  if( nData>1 && sqlite3_value_type(apData[0])==SQLITE_INTEGER ){
+    char *zSep = " SET";
+    z = sqlite3_mprintf("UPDATE %Q", pVtab->zTableName);
+    if( !z ){
+      rc = SQLITE_NOMEM;
+    }
+
+    bindArgOne = (apData[1] && sqlite3_value_type(apData[1])==SQLITE_INTEGER);
+    bindArgZero = 1;
+
+    if( bindArgOne ){
+       string_concat(&z, " SET rowid=?1 ", 0, &rc);
+       zSep = ",";
+    }
+    for(i=2; i<nData; i++){
+      if( apData[i]==0 ) continue;
+      string_concat(&z, sqlite3_mprintf(
+          "%s %Q=?%d", zSep, pVtab->aCol[i-2], i), 1, &rc);
+      zSep = ",";
+    }
+    string_concat(&z, sqlite3_mprintf(" WHERE rowid=?%d", nData), 1, &rc);
+  }
+
+  /* If apData[0] is an integer and nData==1 then do a DELETE */
+  else if( nData==1 && sqlite3_value_type(apData[0])==SQLITE_INTEGER ){
+    z = sqlite3_mprintf("DELETE FROM %Q WHERE rowid = ?1", pVtab->zTableName);
+    if( !z ){
+      rc = SQLITE_NOMEM;
+    }
+    bindArgZero = 1;
+  }
+
+  /* If the first argument is NULL and there are more than two args, INSERT */
+  else if( nData>2 && sqlite3_value_type(apData[0])==SQLITE_NULL ){
+    int ii;
+    char *zInsert = 0;
+    char *zValues = 0;
+  
+    zInsert = sqlite3_mprintf("INSERT INTO %Q (", pVtab->zTableName);
+    if( !zInsert ){
+      rc = SQLITE_NOMEM;
+    }
+    if( sqlite3_value_type(apData[1])==SQLITE_INTEGER ){
+      bindArgOne = 1;
+      zValues = sqlite3_mprintf("?");
+      string_concat(&zInsert, "rowid", 0, &rc);
+    }
+
+    assert((pVtab->nCol+2)==nData);
+    for(ii=2; ii<nData; ii++){
+      string_concat(&zInsert, 
+          sqlite3_mprintf("%s%Q", zValues?", ":"", pVtab->aCol[ii-2]), 1, &rc);
+      string_concat(&zValues, 
+          sqlite3_mprintf("%s?%d", zValues?", ":"", ii), 1, &rc);
+    }
+
+    string_concat(&z, zInsert, 1, &rc);
+    string_concat(&z, ") VALUES(", 0, &rc);
+    string_concat(&z, zValues, 1, &rc);
+    string_concat(&z, ")", 0, &rc);
+  }
+
+  /* Anything else is an error */
+  else{
+    assert(0);
+    return SQLITE_ERROR;
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_prepare(db, z, -1, &pStmt, 0);
+  }
+  assert( rc!=SQLITE_OK || pStmt );
+  sqlite3_free(z);
+  if( rc==SQLITE_OK ) {
+    if( bindArgZero ){
+      sqlite3_bind_value(pStmt, nData, apData[0]);
+    }
+    if( bindArgOne ){
+      sqlite3_bind_value(pStmt, 1, apData[1]);
+    }
+    for(i=2; i<nData && rc==SQLITE_OK; i++){
+      if( apData[i] ) rc = sqlite3_bind_value(pStmt, i, apData[i]);
+    }
+    if( rc==SQLITE_OK ){
+      sqlite3_step(pStmt);
+      rc = sqlite3_finalize(pStmt);
+    }else{
+      sqlite3_finalize(pStmt);
+    }
+  }
+
+  if( pRowid && rc==SQLITE_OK ){
+    *pRowid = sqlite3_last_insert_rowid(db);
+  }
+  if( rc!=SQLITE_OK ){
+    tab->zErrMsg = sqlite3_mprintf("echo-vtab-error: %s", sqlite3_errmsg(db));
+  }
+
+  return rc;
+}
+
+/*
+** xBegin, xSync, xCommit and xRollback callbacks for echo module
+** virtual tables. Do nothing other than add the name of the callback
+** to the $::echo_module Tcl variable.
+*/
+static int echoTransactionCall(sqlite3_vtab *tab, const char *zCall){
+  char *z;
+  echo_vtab *pVtab = (echo_vtab *)tab;
+  z = sqlite3_mprintf("echo(%s)", pVtab->zTableName);
+  if( z==0 ) return SQLITE_NOMEM;
+  appendToEchoModule(pVtab->interp, zCall);
+  appendToEchoModule(pVtab->interp, z);
+  sqlite3_free(z);
+  return SQLITE_OK;
+}
+static int echoBegin(sqlite3_vtab *tab){
+  int rc;
+  echo_vtab *pVtab = (echo_vtab *)tab;
+  Tcl_Interp *interp = pVtab->interp;
+  const char *zVal; 
+
+  /* Ticket #3083 - do not start a transaction if we are already in
+  ** a transaction */
+  assert( !pVtab->inTransaction );
+
+  if( simulateVtabError(pVtab, "xBegin") ){
+    return SQLITE_ERROR;
+  }
+
+  rc = echoTransactionCall(tab, "xBegin");
+
+  if( rc==SQLITE_OK ){
+    /* Check if the $::echo_module_begin_fail variable is defined. If it is,
+    ** and it is set to the name of the real table underlying this virtual
+    ** echo module table, then cause this xSync operation to fail.
+    */
+    zVal = Tcl_GetVar(interp, "echo_module_begin_fail", TCL_GLOBAL_ONLY);
+    if( zVal && 0==strcmp(zVal, pVtab->zTableName) ){
+      rc = SQLITE_ERROR;
+    }
+  }
+  if( rc==SQLITE_OK ){
+    pVtab->inTransaction = 1;
+  }
+  return rc;
+}
+static int echoSync(sqlite3_vtab *tab){
+  int rc;
+  echo_vtab *pVtab = (echo_vtab *)tab;
+  Tcl_Interp *interp = pVtab->interp;
+  const char *zVal; 
+
+  /* Ticket #3083 - Only call xSync if we have previously started a
+  ** transaction */
+  assert( pVtab->inTransaction );
+
+  if( simulateVtabError(pVtab, "xSync") ){
+    return SQLITE_ERROR;
+  }
+
+  rc = echoTransactionCall(tab, "xSync");
+
+  if( rc==SQLITE_OK ){
+    /* Check if the $::echo_module_sync_fail variable is defined. If it is,
+    ** and it is set to the name of the real table underlying this virtual
+    ** echo module table, then cause this xSync operation to fail.
+    */
+    zVal = Tcl_GetVar(interp, "echo_module_sync_fail", TCL_GLOBAL_ONLY);
+    if( zVal && 0==strcmp(zVal, pVtab->zTableName) ){
+      rc = -1;
+    }
+  }
+  return rc;
+}
+static int echoCommit(sqlite3_vtab *tab){
+  echo_vtab *pVtab = (echo_vtab*)tab;
+  int rc;
+
+  /* Ticket #3083 - Only call xCommit if we have previously started
+  ** a transaction */
+  assert( pVtab->inTransaction );
+
+  if( simulateVtabError(pVtab, "xCommit") ){
+    return SQLITE_ERROR;
+  }
+
+  sqlite3BeginBenignMalloc();
+  rc = echoTransactionCall(tab, "xCommit");
+  sqlite3EndBenignMalloc();
+  pVtab->inTransaction = 0;
+  return rc;
+}
+static int echoRollback(sqlite3_vtab *tab){
+  int rc;
+  echo_vtab *pVtab = (echo_vtab*)tab;
+
+  /* Ticket #3083 - Only call xRollback if we have previously started
+  ** a transaction */
+  assert( pVtab->inTransaction );
+
+  rc = echoTransactionCall(tab, "xRollback");
+  pVtab->inTransaction = 0;
+  return rc;
+}
+
+/*
+** Implementation of "GLOB" function on the echo module.  Pass
+** all arguments to the ::echo_glob_overload procedure of TCL
+** and return the result of that procedure as a string.
+*/
+static void overloadedGlobFunction(
+  sqlite3_context *pContext,
+  int nArg,
+  sqlite3_value **apArg
+){
+  Tcl_Interp *interp = sqlite3_user_data(pContext);
+  Tcl_DString str;
+  int i;
+  int rc;
+  Tcl_DStringInit(&str);
+  Tcl_DStringAppendElement(&str, "::echo_glob_overload");
+  for(i=0; i<nArg; i++){
+    Tcl_DStringAppendElement(&str, (char*)sqlite3_value_text(apArg[i]));
+  }
+  rc = Tcl_Eval(interp, Tcl_DStringValue(&str));
+  Tcl_DStringFree(&str);
+  if( rc ){
+    sqlite3_result_error(pContext, Tcl_GetStringResult(interp), -1);
+  }else{
+    sqlite3_result_text(pContext, Tcl_GetStringResult(interp),
+                        -1, SQLITE_TRANSIENT);
+  }
+  Tcl_ResetResult(interp);
+}
+
+/*
+** This is the xFindFunction implementation for the echo module.
+** SQLite calls this routine when the first argument of a function
+** is a column of an echo virtual table.  This routine can optionally
+** override the implementation of that function.  It will choose to
+** do so if the function is named "glob", and a TCL command named
+** ::echo_glob_overload exists.
+*/
+static int echoFindFunction(
+  sqlite3_vtab *vtab,
+  int nArg,
+  const char *zFuncName,
+  void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
+  void **ppArg
+){
+  echo_vtab *pVtab = (echo_vtab *)vtab;
+  Tcl_Interp *interp = pVtab->interp;
+  Tcl_CmdInfo info;
+  if( strcmp(zFuncName,"glob")!=0 ){
+    return 0;
+  }
+  if( Tcl_GetCommandInfo(interp, "::echo_glob_overload", &info)==0 ){
+    return 0;
+  }
+  *pxFunc = overloadedGlobFunction;
+  *ppArg = interp;
+  return 1;
+}
+
+static int echoRename(sqlite3_vtab *vtab, const char *zNewName){
+  int rc = SQLITE_OK;
+  echo_vtab *p = (echo_vtab *)vtab;
+
+  if( simulateVtabError(p, "xRename") ){
+    return SQLITE_ERROR;
+  }
+
+  if( p->isPattern ){
+    int nThis = strlen(p->zThis);
+    char *zSql = sqlite3MPrintf(0, "ALTER TABLE %s RENAME TO %s%s", 
+        p->zTableName, zNewName, &p->zTableName[nThis]
+    );
+    rc = sqlite3_exec(p->db, zSql, 0, 0, 0);
+    sqlite3_free(zSql);
+  }
+
+  return rc;
+}
+
+/*
+** A virtual table module that merely "echos" the contents of another
+** table (like an SQL VIEW).
+*/
+static sqlite3_module echoModule = {
+  0,                         /* iVersion */
+  echoCreate,
+  echoConnect,
+  echoBestIndex,
+  echoDisconnect, 
+  echoDestroy,
+  echoOpen,                  /* xOpen - open a cursor */
+  echoClose,                 /* xClose - close a cursor */
+  echoFilter,                /* xFilter - configure scan constraints */
+  echoNext,                  /* xNext - advance a cursor */
+  echoEof,                   /* xEof */
+  echoColumn,                /* xColumn - read data */
+  echoRowid,                 /* xRowid - read data */
+  echoUpdate,                /* xUpdate - write data */
+  echoBegin,                 /* xBegin - begin transaction */
+  echoSync,                  /* xSync - sync transaction */
+  echoCommit,                /* xCommit - commit transaction */
+  echoRollback,              /* xRollback - rollback transaction */
+  echoFindFunction,          /* xFindFunction - function overloading */
+  echoRename,                /* xRename - rename the table */
+};
+
+/*
+** Decode a pointer to an sqlite3 object.
+*/
+extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
+
+static void moduleDestroy(void *p){
+  sqlite3_free(p);
+}
+
+/*
+** Register the echo virtual table module.
+*/
+static int register_echo_module(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3 *db;
+  EchoModule *pMod;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  pMod = sqlite3_malloc(sizeof(EchoModule));
+  pMod->interp = interp;
+  sqlite3_create_module_v2(db, "echo", &echoModule, (void*)pMod, moduleDestroy);
+  return TCL_OK;
+}
+
+/*
+** Tcl interface to sqlite3_declare_vtab, invoked as follows from Tcl:
+**
+** sqlite3_declare_vtab DB SQL
+*/
+static int declare_vtab(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3 *db;
+  int rc;
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB SQL");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  rc = sqlite3_declare_vtab(db, Tcl_GetString(objv[2]));
+  if( rc!=SQLITE_OK ){
+    Tcl_SetResult(interp, (char *)sqlite3_errmsg(db), TCL_VOLATILE);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest8_Init(Tcl_Interp *interp){
+  static struct {
+     char *zName;
+     Tcl_ObjCmdProc *xProc;
+     void *clientData;
+  } aObjCmd[] = {
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+     { "register_echo_module",   register_echo_module, 0 },
+     { "sqlite3_declare_vtab",   declare_vtab, 0 },
+#endif
+  };
+  int i;
+  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
+    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 
+        aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
+  }
+  return TCL_OK;
+}
diff --git a/third_party/sqlite/src/test9.c b/third_party/sqlite/src/test9.c
new file mode 100755
index 0000000..2043da2
--- /dev/null
+++ b/third_party/sqlite/src/test9.c
@@ -0,0 +1,193 @@
+/*
+** 2007 March 29
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains obscure tests of the C-interface required
+** for completeness. Test code is written in C for these cases
+** as there is not much point in binding to Tcl.
+**
+** $Id: test9.c,v 1.6 2008/07/11 13:53:55 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "tcl.h"
+#include <stdlib.h>
+#include <string.h>
+
+/*
+** c_collation_test
+*/
+static int c_collation_test(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  const char *zErrFunction = "N/A";
+  sqlite3 *db;
+
+  int rc;
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+
+  /* Open a database. */
+  rc = sqlite3_open(":memory:", &db);
+  if( rc!=SQLITE_OK ){
+    zErrFunction = "sqlite3_open";
+    goto error_out;
+  }
+
+  rc = sqlite3_create_collation(db, "collate", 456, 0, 0);
+  if( rc!=SQLITE_MISUSE ){
+    sqlite3_close(db);
+    zErrFunction = "sqlite3_create_collation";
+    goto error_out;
+  }
+
+  sqlite3_close(db);
+  return TCL_OK;
+
+error_out:
+  Tcl_ResetResult(interp);
+  Tcl_AppendResult(interp, "Error testing function: ", zErrFunction, 0);
+  return TCL_ERROR;
+}
+
+/*
+** c_realloc_test
+*/
+static int c_realloc_test(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  void *p;
+  const char *zErrFunction = "N/A";
+
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+
+  p = sqlite3_malloc(5);
+  if( !p ){
+    zErrFunction = "sqlite3_malloc";
+    goto error_out;
+  }
+
+  /* Test that realloc()ing a block of memory to a negative size is
+  ** the same as free()ing that memory.
+  */
+  p = sqlite3_realloc(p, -1);
+  if( p ){
+    zErrFunction = "sqlite3_realloc";
+    goto error_out;
+  }
+
+  return TCL_OK;
+
+error_out:
+  Tcl_ResetResult(interp);
+  Tcl_AppendResult(interp, "Error testing function: ", zErrFunction, 0);
+  return TCL_ERROR;
+}
+
+
+/*
+** c_misuse_test
+*/
+static int c_misuse_test(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  const char *zErrFunction = "N/A";
+  sqlite3 *db = 0;
+  int rc;
+
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+
+  /* Open a database. Then close it again. We need to do this so that
+  ** we have a "closed database handle" to pass to various API functions.
+  */
+  rc = sqlite3_open(":memory:", &db);
+  if( rc!=SQLITE_OK ){
+    zErrFunction = "sqlite3_open";
+    goto error_out;
+  }
+  sqlite3_close(db);
+
+
+  rc = sqlite3_errcode(db);
+  if( rc!=SQLITE_MISUSE ){
+    zErrFunction = "sqlite3_errcode";
+    goto error_out;
+  }
+
+  rc = sqlite3_prepare(db, 0, 0, 0, 0);
+  if( rc!=SQLITE_MISUSE ){
+    zErrFunction = "sqlite3_prepare";
+    goto error_out;
+  }
+
+  rc = sqlite3_prepare_v2(db, 0, 0, 0, 0);
+  if( rc!=SQLITE_MISUSE ){
+    zErrFunction = "sqlite3_prepare_v2";
+    goto error_out;
+  }
+
+#ifndef SQLITE_OMIT_UTF16
+  rc = sqlite3_prepare16(db, 0, 0, 0, 0);
+  if( rc!=SQLITE_MISUSE ){
+    zErrFunction = "sqlite3_prepare16";
+    goto error_out;
+  }
+  rc = sqlite3_prepare16_v2(db, 0, 0, 0, 0);
+  if( rc!=SQLITE_MISUSE ){
+    zErrFunction = "sqlite3_prepare16_v2";
+    goto error_out;
+  }
+#endif
+
+  return TCL_OK;
+
+error_out:
+  Tcl_ResetResult(interp);
+  Tcl_AppendResult(interp, "Error testing function: ", zErrFunction, 0);
+  return TCL_ERROR;
+}
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest9_Init(Tcl_Interp *interp){
+  static struct {
+     char *zName;
+     Tcl_ObjCmdProc *xProc;
+     void *clientData;
+  } aObjCmd[] = {
+     { "c_misuse_test",    c_misuse_test, 0 },
+     { "c_realloc_test",   c_realloc_test, 0 },
+     { "c_collation_test", c_collation_test, 0 },
+  };
+  int i;
+  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
+    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 
+        aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
+  }
+  return TCL_OK;
+}
diff --git a/third_party/sqlite/src/test_async.c b/third_party/sqlite/src/test_async.c
new file mode 100755
index 0000000..7b48afe
--- /dev/null
+++ b/third_party/sqlite/src/test_async.c
@@ -0,0 +1,1717 @@
+/*
+** 2005 December 14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** $Id: test_async.c,v 1.45 2008/06/26 10:41:19 danielk1977 Exp $
+**
+** This file contains an example implementation of an asynchronous IO 
+** backend for SQLite.
+**
+** WHAT IS ASYNCHRONOUS I/O?
+**
+** With asynchronous I/O, write requests are handled by a separate thread
+** running in the background.  This means that the thread that initiates
+** a database write does not have to wait for (sometimes slow) disk I/O
+** to occur.  The write seems to happen very quickly, though in reality
+** it is happening at its usual slow pace in the background.
+**
+** Asynchronous I/O appears to give better responsiveness, but at a price.
+** You lose the Durable property.  With the default I/O backend of SQLite,
+** once a write completes, you know that the information you wrote is
+** safely on disk.  With the asynchronous I/O, this is not the case.  If
+** your program crashes or if a power lose occurs after the database
+** write but before the asynchronous write thread has completed, then the
+** database change might never make it to disk and the next user of the
+** database might not see your change.
+**
+** You lose Durability with asynchronous I/O, but you still retain the
+** other parts of ACID:  Atomic,  Consistent, and Isolated.  Many
+** appliations get along fine without the Durablity.
+**
+** HOW IT WORKS
+**
+** Asynchronous I/O works by creating a special SQLite "vfs" structure
+** and registering it with sqlite3_vfs_register(). When files opened via 
+** this vfs are written to (using sqlite3OsWrite()), the data is not 
+** written directly to disk, but is placed in the "write-queue" to be
+** handled by the background thread.
+**
+** When files opened with the asynchronous vfs are read from 
+** (using sqlite3OsRead()), the data is read from the file on 
+** disk and the write-queue, so that from the point of view of
+** the vfs reader the OsWrite() appears to have already completed.
+**
+** The special vfs is registered (and unregistered) by calls to 
+** function asyncEnable() (see below).
+**
+** LIMITATIONS
+**
+** This demonstration code is deliberately kept simple in order to keep
+** the main ideas clear and easy to understand.  Real applications that
+** want to do asynchronous I/O might want to add additional capabilities.
+** For example, in this demonstration if writes are happening at a steady
+** stream that exceeds the I/O capability of the background writer thread,
+** the queue of pending write operations will grow without bound until we
+** run out of memory.  Users of this technique may want to keep track of
+** the quantity of pending writes and stop accepting new write requests
+** when the buffer gets to be too big.
+**
+** LOCKING + CONCURRENCY
+**
+** Multiple connections from within a single process that use this
+** implementation of asynchronous IO may access a single database
+** file concurrently. From the point of view of the user, if all
+** connections are from within a single process, there is no difference
+** between the concurrency offered by "normal" SQLite and SQLite
+** using the asynchronous backend.
+**
+** If connections from within multiple database files may access the
+** database file, the ENABLE_FILE_LOCKING symbol (see below) must be
+** defined. If it is not defined, then no locks are established on 
+** the database file. In this case, if multiple processes access 
+** the database file, corruption will quickly result.
+**
+** If ENABLE_FILE_LOCKING is defined (the default), then connections 
+** from within multiple processes may access a single database file 
+** without risking corruption. However concurrency is reduced as
+** follows:
+**
+**   * When a connection using asynchronous IO begins a database
+**     transaction, the database is locked immediately. However the
+**     lock is not released until after all relevant operations
+**     in the write-queue have been flushed to disk. This means
+**     (for example) that the database may remain locked for some 
+**     time after a "COMMIT" or "ROLLBACK" is issued.
+**
+**   * If an application using asynchronous IO executes transactions
+**     in quick succession, other database users may be effectively
+**     locked out of the database. This is because when a BEGIN
+**     is executed, a database lock is established immediately. But
+**     when the corresponding COMMIT or ROLLBACK occurs, the lock
+**     is not released until the relevant part of the write-queue 
+**     has been flushed through. As a result, if a COMMIT is followed
+**     by a BEGIN before the write-queue is flushed through, the database 
+**     is never unlocked,preventing other processes from accessing 
+**     the database.
+**
+** Defining ENABLE_FILE_LOCKING when using an NFS or other remote 
+** file-system may slow things down, as synchronous round-trips to the 
+** server may be required to establish database file locks.
+*/
+#define ENABLE_FILE_LOCKING
+
+#ifndef SQLITE_AMALGAMATION
+# include "sqliteInt.h"
+#endif
+#include <tcl.h>
+
+/*
+** This test uses pthreads and hence only works on unix and with
+** a threadsafe build of SQLite.
+*/
+#if SQLITE_OS_UNIX && SQLITE_THREADSAFE
+
+/*
+** This demo uses pthreads.  If you do not have a pthreads implementation
+** for your operating system, you will need to recode the threading 
+** logic.
+*/
+#include <pthread.h>
+#include <sched.h>
+
+/* Useful macros used in several places */
+#define MIN(x,y) ((x)<(y)?(x):(y))
+#define MAX(x,y) ((x)>(y)?(x):(y))
+
+/* Forward references */
+typedef struct AsyncWrite AsyncWrite;
+typedef struct AsyncFile AsyncFile;
+typedef struct AsyncFileData AsyncFileData;
+typedef struct AsyncFileLock AsyncFileLock;
+typedef struct AsyncLock AsyncLock;
+
+/* Enable for debugging */
+static int sqlite3async_trace = 0;
+# define ASYNC_TRACE(X) if( sqlite3async_trace ) asyncTrace X
+static void asyncTrace(const char *zFormat, ...){
+  char *z;
+  va_list ap;
+  va_start(ap, zFormat);
+  z = sqlite3_vmprintf(zFormat, ap);
+  va_end(ap);
+  fprintf(stderr, "[%d] %s", (int)pthread_self(), z);
+  sqlite3_free(z);
+}
+
+/*
+** THREAD SAFETY NOTES
+**
+** Basic rules:
+**
+**     * Both read and write access to the global write-op queue must be 
+**       protected by the async.queueMutex. As are the async.ioError and
+**       async.nFile variables.
+**
+**     * The async.aLock hash-table and all AsyncLock and AsyncFileLock
+**       structures must be protected by the async.lockMutex mutex.
+**
+**     * The file handles from the underlying system are assumed not to 
+**       be thread safe.
+**
+**     * See the last two paragraphs under "The Writer Thread" for
+**       an assumption to do with file-handle synchronization by the Os.
+**
+** Deadlock prevention:
+**
+**     There are three mutex used by the system: the "writer" mutex, 
+**     the "queue" mutex and the "lock" mutex. Rules are:
+**
+**     * It is illegal to block on the writer mutex when any other mutex
+**       are held, and 
+**
+**     * It is illegal to block on the queue mutex when the lock mutex
+**       is held.
+**
+**     i.e. mutex's must be grabbed in the order "writer", "queue", "lock".
+**
+** File system operations (invoked by SQLite thread):
+**
+**     xOpen
+**     xDelete
+**     xFileExists
+**
+** File handle operations (invoked by SQLite thread):
+**
+**         asyncWrite, asyncClose, asyncTruncate, asyncSync 
+**    
+**     The operations above add an entry to the global write-op list. They
+**     prepare the entry, acquire the async.queueMutex momentarily while
+**     list pointers are  manipulated to insert the new entry, then release
+**     the mutex and signal the writer thread to wake up in case it happens
+**     to be asleep.
+**
+**    
+**         asyncRead, asyncFileSize.
+**
+**     Read operations. Both of these read from both the underlying file
+**     first then adjust their result based on pending writes in the 
+**     write-op queue.   So async.queueMutex is held for the duration
+**     of these operations to prevent other threads from changing the
+**     queue in mid operation.
+**    
+**
+**         asyncLock, asyncUnlock, asyncCheckReservedLock
+**    
+**     These primitives implement in-process locking using a hash table
+**     on the file name.  Files are locked correctly for connections coming
+**     from the same process.  But other processes cannot see these locks
+**     and will therefore not honor them.
+**
+**
+** The writer thread:
+**
+**     The async.writerMutex is used to make sure only there is only
+**     a single writer thread running at a time.
+**
+**     Inside the writer thread is a loop that works like this:
+**
+**         WHILE (write-op list is not empty)
+**             Do IO operation at head of write-op list
+**             Remove entry from head of write-op list
+**         END WHILE
+**
+**     The async.queueMutex is always held during the <write-op list is 
+**     not empty> test, and when the entry is removed from the head
+**     of the write-op list. Sometimes it is held for the interim
+**     period (while the IO is performed), and sometimes it is
+**     relinquished. It is relinquished if (a) the IO op is an
+**     ASYNC_CLOSE or (b) when the file handle was opened, two of
+**     the underlying systems handles were opened on the same
+**     file-system entry.
+**
+**     If condition (b) above is true, then one file-handle 
+**     (AsyncFile.pBaseRead) is used exclusively by sqlite threads to read the
+**     file, the other (AsyncFile.pBaseWrite) by sqlite3_async_flush() 
+**     threads to perform write() operations. This means that read 
+**     operations are not blocked by asynchronous writes (although 
+**     asynchronous writes may still be blocked by reads).
+**
+**     This assumes that the OS keeps two handles open on the same file
+**     properly in sync. That is, any read operation that starts after a
+**     write operation on the same file system entry has completed returns
+**     data consistent with the write. We also assume that if one thread 
+**     reads a file while another is writing it all bytes other than the
+**     ones actually being written contain valid data.
+**
+**     If the above assumptions are not true, set the preprocessor symbol
+**     SQLITE_ASYNC_TWO_FILEHANDLES to 0.
+*/
+
+#ifndef SQLITE_ASYNC_TWO_FILEHANDLES
+/* #define SQLITE_ASYNC_TWO_FILEHANDLES 0 */
+#define SQLITE_ASYNC_TWO_FILEHANDLES 1
+#endif
+
+/*
+** State information is held in the static variable "async" defined
+** as the following structure.
+**
+** Both async.ioError and async.nFile are protected by async.queueMutex.
+*/
+static struct TestAsyncStaticData {
+  pthread_mutex_t lockMutex;   /* For access to aLock hash table */
+  pthread_mutex_t queueMutex;  /* Mutex for access to write operation queue */
+  pthread_mutex_t writerMutex; /* Prevents multiple writer threads */
+  pthread_cond_t queueSignal;  /* For waking up sleeping writer thread */
+  pthread_cond_t emptySignal;  /* Notify when the write queue is empty */
+  AsyncWrite *pQueueFirst;     /* Next write operation to be processed */
+  AsyncWrite *pQueueLast;      /* Last write operation on the list */
+  Hash aLock;                  /* Files locked */
+  volatile int ioDelay;             /* Extra delay between write operations */
+  volatile int writerHaltWhenIdle;  /* Writer thread halts when queue empty */
+  volatile int writerHaltNow;       /* Writer thread halts after next op */
+  int ioError;                 /* True if an IO error has occured */
+  int nFile;                   /* Number of open files (from sqlite pov) */
+} async = {
+  PTHREAD_MUTEX_INITIALIZER,
+  PTHREAD_MUTEX_INITIALIZER,
+  PTHREAD_MUTEX_INITIALIZER,
+  PTHREAD_COND_INITIALIZER,
+  PTHREAD_COND_INITIALIZER,
+};
+
+/* Possible values of AsyncWrite.op */
+#define ASYNC_NOOP          0
+#define ASYNC_WRITE         1
+#define ASYNC_SYNC          2
+#define ASYNC_TRUNCATE      3
+#define ASYNC_CLOSE         4
+#define ASYNC_DELETE        5
+#define ASYNC_OPENEXCLUSIVE 6
+#define ASYNC_UNLOCK        7
+
+/* Names of opcodes.  Used for debugging only.
+** Make sure these stay in sync with the macros above!
+*/
+static const char *azOpcodeName[] = {
+  "NOOP", "WRITE", "SYNC", "TRUNCATE", "CLOSE", "DELETE", "OPENEX", "UNLOCK"
+};
+
+/*
+** Entries on the write-op queue are instances of the AsyncWrite
+** structure, defined here.
+**
+** The interpretation of the iOffset and nByte variables varies depending 
+** on the value of AsyncWrite.op:
+**
+** ASYNC_NOOP:
+**     No values used.
+**
+** ASYNC_WRITE:
+**     iOffset -> Offset in file to write to.
+**     nByte   -> Number of bytes of data to write (pointed to by zBuf).
+**
+** ASYNC_SYNC:
+**     nByte   -> flags to pass to sqlite3OsSync().
+**
+** ASYNC_TRUNCATE:
+**     iOffset -> Size to truncate file to.
+**     nByte   -> Unused.
+**
+** ASYNC_CLOSE:
+**     iOffset -> Unused.
+**     nByte   -> Unused.
+**
+** ASYNC_DELETE:
+**     iOffset -> Contains the "syncDir" flag.
+**     nByte   -> Number of bytes of zBuf points to (file name).
+**
+** ASYNC_OPENEXCLUSIVE:
+**     iOffset -> Value of "delflag".
+**     nByte   -> Number of bytes of zBuf points to (file name).
+**
+** ASYNC_UNLOCK:
+**     nByte   -> Argument to sqlite3OsUnlock().
+**
+**
+** For an ASYNC_WRITE operation, zBuf points to the data to write to the file. 
+** This space is sqlite3_malloc()d along with the AsyncWrite structure in a
+** single blob, so is deleted when sqlite3_free() is called on the parent 
+** structure.
+*/
+struct AsyncWrite {
+  AsyncFileData *pFileData;    /* File to write data to or sync */
+  int op;                      /* One of ASYNC_xxx etc. */
+  i64 iOffset;        /* See above */
+  int nByte;          /* See above */
+  char *zBuf;         /* Data to write to file (or NULL if op!=ASYNC_WRITE) */
+  AsyncWrite *pNext;  /* Next write operation (to any file) */
+};
+
+/*
+** An instance of this structure is created for each distinct open file 
+** (i.e. if two handles are opened on the one file, only one of these
+** structures is allocated) and stored in the async.aLock hash table. The
+** keys for async.aLock are the full pathnames of the opened files.
+**
+** AsyncLock.pList points to the head of a linked list of AsyncFileLock
+** structures, one for each handle currently open on the file.
+**
+** If the opened file is not a main-database (the SQLITE_OPEN_MAIN_DB is
+** not passed to the sqlite3OsOpen() call), or if ENABLE_FILE_LOCKING is 
+** not defined at compile time, variables AsyncLock.pFile and 
+** AsyncLock.eLock are never used. Otherwise, pFile is a file handle
+** opened on the file in question and used to obtain the file-system 
+** locks required by database connections within this process.
+**
+** See comments above the asyncLock() function for more details on 
+** the implementation of database locking used by this backend.
+*/
+struct AsyncLock {
+  sqlite3_file *pFile;
+  int eLock;
+  AsyncFileLock *pList;
+};
+
+/*
+** An instance of the following structure is allocated along with each
+** AsyncFileData structure (see AsyncFileData.lock), but is only used if the
+** file was opened with the SQLITE_OPEN_MAIN_DB.
+*/
+struct AsyncFileLock {
+  int eLock;                /* Internally visible lock state (sqlite pov) */
+  int eAsyncLock;           /* Lock-state with write-queue unlock */
+  AsyncFileLock *pNext;
+};
+
+/* 
+** The AsyncFile structure is a subclass of sqlite3_file used for 
+** asynchronous IO. 
+**
+** All of the actual data for the structure is stored in the structure
+** pointed to by AsyncFile.pData, which is allocated as part of the
+** sqlite3OsOpen() using sqlite3_malloc(). The reason for this is that the
+** lifetime of the AsyncFile structure is ended by the caller after OsClose()
+** is called, but the data in AsyncFileData may be required by the
+** writer thread after that point.
+*/
+struct AsyncFile {
+  sqlite3_io_methods *pMethod;
+  AsyncFileData *pData;
+};
+struct AsyncFileData {
+  char *zName;               /* Underlying OS filename - used for debugging */
+  int nName;                 /* Number of characters in zName */
+  sqlite3_file *pBaseRead;   /* Read handle to the underlying Os file */
+  sqlite3_file *pBaseWrite;  /* Write handle to the underlying Os file */
+  AsyncFileLock lock;
+  AsyncWrite close;
+};
+
+/*
+** The following async_XXX functions are debugging wrappers around the
+** corresponding pthread_XXX functions:
+**
+**     pthread_mutex_lock();
+**     pthread_mutex_unlock();
+**     pthread_mutex_trylock();
+**     pthread_cond_wait();
+**
+** It is illegal to pass any mutex other than those stored in the
+** following global variables of these functions.
+**
+**     async.queueMutex
+**     async.writerMutex
+**     async.lockMutex
+**
+** If NDEBUG is defined, these wrappers do nothing except call the 
+** corresponding pthreads function. If NDEBUG is not defined, then the
+** following variables are used to store the thread-id (as returned
+** by pthread_self()) currently holding the mutex, or 0 otherwise:
+**
+**     asyncdebug.queueMutexHolder
+**     asyncdebug.writerMutexHolder
+**     asyncdebug.lockMutexHolder
+**
+** These variables are used by some assert() statements that verify
+** the statements made in the "Deadlock Prevention" notes earlier
+** in this file.
+*/
+#ifndef NDEBUG
+
+static struct TestAsyncDebugData {
+  pthread_t lockMutexHolder;
+  pthread_t queueMutexHolder;
+  pthread_t writerMutexHolder;
+} asyncdebug = {0, 0, 0};
+
+/*
+** Wrapper around pthread_mutex_lock(). Checks that we have not violated
+** the anti-deadlock rules (see "Deadlock prevention" above).
+*/
+static int async_mutex_lock(pthread_mutex_t *pMutex){
+  int iIdx;
+  int rc;
+  pthread_mutex_t *aMutex = (pthread_mutex_t *)(&async);
+  pthread_t *aHolder = (pthread_t *)(&asyncdebug);
+
+  /* The code in this 'ifndef NDEBUG' block depends on a certain alignment
+   * of the variables in TestAsyncStaticData and TestAsyncDebugData. The
+   * following assert() statements check that this has not been changed.
+   *
+   * Really, these only need to be run once at startup time.
+   */
+  assert(&(aMutex[0])==&async.lockMutex);
+  assert(&(aMutex[1])==&async.queueMutex);
+  assert(&(aMutex[2])==&async.writerMutex);
+  assert(&(aHolder[0])==&asyncdebug.lockMutexHolder);
+  assert(&(aHolder[1])==&asyncdebug.queueMutexHolder);
+  assert(&(aHolder[2])==&asyncdebug.writerMutexHolder);
+
+  assert( pthread_self()!=0 );
+
+  for(iIdx=0; iIdx<3; iIdx++){
+    if( pMutex==&aMutex[iIdx] ) break;
+
+    /* This is the key assert(). Here we are checking that if the caller
+     * is trying to block on async.writerMutex, neither of the other two
+     * mutex are held. If the caller is trying to block on async.queueMutex,
+     * lockMutex is not held.
+     */
+    assert(!pthread_equal(aHolder[iIdx], pthread_self()));
+  }
+  assert(iIdx<3);
+
+  rc = pthread_mutex_lock(pMutex);
+  if( rc==0 ){
+    assert(aHolder[iIdx]==0);
+    aHolder[iIdx] = pthread_self();
+  }
+  return rc;
+}
+
+/*
+** Wrapper around pthread_mutex_unlock().
+*/
+static int async_mutex_unlock(pthread_mutex_t *pMutex){
+  int iIdx;
+  int rc;
+  pthread_mutex_t *aMutex = (pthread_mutex_t *)(&async);
+  pthread_t *aHolder = (pthread_t *)(&asyncdebug);
+
+  for(iIdx=0; iIdx<3; iIdx++){
+    if( pMutex==&aMutex[iIdx] ) break;
+  }
+  assert(iIdx<3);
+
+  assert(pthread_equal(aHolder[iIdx], pthread_self()));
+  aHolder[iIdx] = 0;
+  rc = pthread_mutex_unlock(pMutex);
+  assert(rc==0);
+
+  return 0;
+}
+
+/*
+** Wrapper around pthread_mutex_trylock().
+*/
+static int async_mutex_trylock(pthread_mutex_t *pMutex){
+  int iIdx;
+  int rc;
+  pthread_mutex_t *aMutex = (pthread_mutex_t *)(&async);
+  pthread_t *aHolder = (pthread_t *)(&asyncdebug);
+
+  for(iIdx=0; iIdx<3; iIdx++){
+    if( pMutex==&aMutex[iIdx] ) break;
+  }
+  assert(iIdx<3);
+
+  rc = pthread_mutex_trylock(pMutex);
+  if( rc==0 ){
+    assert(aHolder[iIdx]==0);
+    aHolder[iIdx] = pthread_self();
+  }
+  return rc;
+}
+
+/*
+** Wrapper around pthread_cond_wait().
+*/
+static int async_cond_wait(pthread_cond_t *pCond, pthread_mutex_t *pMutex){
+  int iIdx;
+  int rc;
+  pthread_mutex_t *aMutex = (pthread_mutex_t *)(&async);
+  pthread_t *aHolder = (pthread_t *)(&asyncdebug);
+
+  for(iIdx=0; iIdx<3; iIdx++){
+    if( pMutex==&aMutex[iIdx] ) break;
+  }
+  assert(iIdx<3);
+
+  assert(pthread_equal(aHolder[iIdx],pthread_self()));
+  aHolder[iIdx] = 0;
+  rc = pthread_cond_wait(pCond, pMutex);
+  if( rc==0 ){
+    aHolder[iIdx] = pthread_self();
+  }
+  return rc;
+}
+
+/* Call our async_XX wrappers instead of selected pthread_XX functions */
+#define pthread_mutex_lock    async_mutex_lock
+#define pthread_mutex_unlock  async_mutex_unlock
+#define pthread_mutex_trylock async_mutex_trylock
+#define pthread_cond_wait     async_cond_wait
+
+#endif   /* !defined(NDEBUG) */
+
+/*
+** Add an entry to the end of the global write-op list. pWrite should point 
+** to an AsyncWrite structure allocated using sqlite3_malloc().  The writer
+** thread will call sqlite3_free() to free the structure after the specified
+** operation has been completed.
+**
+** Once an AsyncWrite structure has been added to the list, it becomes the
+** property of the writer thread and must not be read or modified by the
+** caller.  
+*/
+static void addAsyncWrite(AsyncWrite *pWrite){
+  /* We must hold the queue mutex in order to modify the queue pointers */
+  pthread_mutex_lock(&async.queueMutex);
+
+  /* Add the record to the end of the write-op queue */
+  assert( !pWrite->pNext );
+  if( async.pQueueLast ){
+    assert( async.pQueueFirst );
+    async.pQueueLast->pNext = pWrite;
+  }else{
+    async.pQueueFirst = pWrite;
+  }
+  async.pQueueLast = pWrite;
+  ASYNC_TRACE(("PUSH %p (%s %s %d)\n", pWrite, azOpcodeName[pWrite->op],
+         pWrite->pFileData ? pWrite->pFileData->zName : "-", pWrite->iOffset));
+
+  if( pWrite->op==ASYNC_CLOSE ){
+    async.nFile--;
+  }
+
+  /* Drop the queue mutex */
+  pthread_mutex_unlock(&async.queueMutex);
+
+  /* The writer thread might have been idle because there was nothing
+  ** on the write-op queue for it to do.  So wake it up. */
+  pthread_cond_signal(&async.queueSignal);
+}
+
+/*
+** Increment async.nFile in a thread-safe manner.
+*/
+static void incrOpenFileCount(){
+  /* We must hold the queue mutex in order to modify async.nFile */
+  pthread_mutex_lock(&async.queueMutex);
+  if( async.nFile==0 ){
+    async.ioError = SQLITE_OK;
+  }
+  async.nFile++;
+  pthread_mutex_unlock(&async.queueMutex);
+}
+
+/*
+** This is a utility function to allocate and populate a new AsyncWrite
+** structure and insert it (via addAsyncWrite() ) into the global list.
+*/
+static int addNewAsyncWrite(
+  AsyncFileData *pFileData, 
+  int op, 
+  i64 iOffset, 
+  int nByte,
+  const char *zByte
+){
+  AsyncWrite *p;
+  if( op!=ASYNC_CLOSE && async.ioError ){
+    return async.ioError;
+  }
+  p = sqlite3_malloc(sizeof(AsyncWrite) + (zByte?nByte:0));
+  if( !p ){
+    /* The upper layer does not expect operations like OsWrite() to
+    ** return SQLITE_NOMEM. This is partly because under normal conditions
+    ** SQLite is required to do rollback without calling malloc(). So
+    ** if malloc() fails here, treat it as an I/O error. The above
+    ** layer knows how to handle that.
+    */
+    return SQLITE_IOERR;
+  }
+  p->op = op;
+  p->iOffset = iOffset;
+  p->nByte = nByte;
+  p->pFileData = pFileData;
+  p->pNext = 0;
+  if( zByte ){
+    p->zBuf = (char *)&p[1];
+    memcpy(p->zBuf, zByte, nByte);
+  }else{
+    p->zBuf = 0;
+  }
+  addAsyncWrite(p);
+  return SQLITE_OK;
+}
+
+/*
+** Close the file. This just adds an entry to the write-op list, the file is
+** not actually closed.
+*/
+static int asyncClose(sqlite3_file *pFile){
+  AsyncFileData *p = ((AsyncFile *)pFile)->pData;
+
+  /* Unlock the file, if it is locked */
+  pthread_mutex_lock(&async.lockMutex);
+  p->lock.eLock = 0;
+  pthread_mutex_unlock(&async.lockMutex);
+
+  addAsyncWrite(&p->close);
+  return SQLITE_OK;
+}
+
+/*
+** Implementation of sqlite3OsWrite() for asynchronous files. Instead of 
+** writing to the underlying file, this function adds an entry to the end of
+** the global AsyncWrite list. Either SQLITE_OK or SQLITE_NOMEM may be
+** returned.
+*/
+static int asyncWrite(sqlite3_file *pFile, const void *pBuf, int amt, i64 iOff){
+  AsyncFileData *p = ((AsyncFile *)pFile)->pData;
+  return addNewAsyncWrite(p, ASYNC_WRITE, iOff, amt, pBuf);
+}
+
+/*
+** Read data from the file. First we read from the filesystem, then adjust 
+** the contents of the buffer based on ASYNC_WRITE operations in the 
+** write-op queue.
+**
+** This method holds the mutex from start to finish.
+*/
+static int asyncRead(sqlite3_file *pFile, void *zOut, int iAmt, i64 iOffset){
+  AsyncFileData *p = ((AsyncFile *)pFile)->pData;
+  int rc = SQLITE_OK;
+  i64 filesize;
+  int nRead;
+  sqlite3_file *pBase = p->pBaseRead;
+
+  /* Grab the write queue mutex for the duration of the call */
+  pthread_mutex_lock(&async.queueMutex);
+
+  /* If an I/O error has previously occurred in this virtual file 
+  ** system, then all subsequent operations fail.
+  */
+  if( async.ioError!=SQLITE_OK ){
+    rc = async.ioError;
+    goto asyncread_out;
+  }
+
+  if( pBase->pMethods ){
+    rc = sqlite3OsFileSize(pBase, &filesize);
+    if( rc!=SQLITE_OK ){
+      goto asyncread_out;
+    }
+    nRead = MIN(filesize - iOffset, iAmt);
+    if( nRead>0 ){
+      rc = sqlite3OsRead(pBase, zOut, nRead, iOffset);
+      ASYNC_TRACE(("READ %s %d bytes at %d\n", p->zName, nRead, iOffset));
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    AsyncWrite *pWrite;
+    char *zName = p->zName;
+
+    for(pWrite=async.pQueueFirst; pWrite; pWrite = pWrite->pNext){
+      if( pWrite->op==ASYNC_WRITE && pWrite->pFileData->zName==zName ){
+        int iBeginOut = (pWrite->iOffset-iOffset);
+        int iBeginIn = -iBeginOut;
+        int nCopy;
+
+        if( iBeginIn<0 ) iBeginIn = 0;
+        if( iBeginOut<0 ) iBeginOut = 0;
+        nCopy = MIN(pWrite->nByte-iBeginIn, iAmt-iBeginOut);
+
+        if( nCopy>0 ){
+          memcpy(&((char *)zOut)[iBeginOut], &pWrite->zBuf[iBeginIn], nCopy);
+          ASYNC_TRACE(("OVERREAD %d bytes at %d\n", nCopy, iBeginOut+iOffset));
+        }
+      }
+    }
+  }
+
+asyncread_out:
+  pthread_mutex_unlock(&async.queueMutex);
+  return rc;
+}
+
+/*
+** Truncate the file to nByte bytes in length. This just adds an entry to 
+** the write-op list, no IO actually takes place.
+*/
+static int asyncTruncate(sqlite3_file *pFile, i64 nByte){
+  AsyncFileData *p = ((AsyncFile *)pFile)->pData;
+  return addNewAsyncWrite(p, ASYNC_TRUNCATE, nByte, 0, 0);
+}
+
+/*
+** Sync the file. This just adds an entry to the write-op list, the 
+** sync() is done later by sqlite3_async_flush().
+*/
+static int asyncSync(sqlite3_file *pFile, int flags){
+  AsyncFileData *p = ((AsyncFile *)pFile)->pData;
+  return addNewAsyncWrite(p, ASYNC_SYNC, 0, flags, 0);
+}
+
+/*
+** Read the size of the file. First we read the size of the file system 
+** entry, then adjust for any ASYNC_WRITE or ASYNC_TRUNCATE operations 
+** currently in the write-op list. 
+**
+** This method holds the mutex from start to finish.
+*/
+int asyncFileSize(sqlite3_file *pFile, i64 *piSize){
+  AsyncFileData *p = ((AsyncFile *)pFile)->pData;
+  int rc = SQLITE_OK;
+  i64 s = 0;
+  sqlite3_file *pBase;
+
+  pthread_mutex_lock(&async.queueMutex);
+
+  /* Read the filesystem size from the base file. If pBaseRead is NULL, this
+  ** means the file hasn't been opened yet. In this case all relevant data 
+  ** must be in the write-op queue anyway, so we can omit reading from the
+  ** file-system.
+  */
+  pBase = p->pBaseRead;
+  if( pBase->pMethods ){
+    rc = sqlite3OsFileSize(pBase, &s);
+  }
+
+  if( rc==SQLITE_OK ){
+    AsyncWrite *pWrite;
+    for(pWrite=async.pQueueFirst; pWrite; pWrite = pWrite->pNext){
+      if( pWrite->op==ASYNC_DELETE && strcmp(p->zName, pWrite->zBuf)==0 ){
+        s = 0;
+      }else if( pWrite->pFileData && pWrite->pFileData->zName==p->zName){
+        switch( pWrite->op ){
+          case ASYNC_WRITE:
+            s = MAX(pWrite->iOffset + (i64)(pWrite->nByte), s);
+            break;
+          case ASYNC_TRUNCATE:
+            s = MIN(s, pWrite->iOffset);
+            break;
+        }
+      }
+    }
+    *piSize = s;
+  }
+  pthread_mutex_unlock(&async.queueMutex);
+  return rc;
+}
+
+/*
+** Lock or unlock the actual file-system entry.
+*/
+static int getFileLock(AsyncLock *pLock){
+  int rc = SQLITE_OK;
+  AsyncFileLock *pIter;
+  int eRequired = 0;
+
+  if( pLock->pFile ){
+    for(pIter=pLock->pList; pIter; pIter=pIter->pNext){
+      assert(pIter->eAsyncLock>=pIter->eLock);
+      if( pIter->eAsyncLock>eRequired ){
+        eRequired = pIter->eAsyncLock;
+        assert(eRequired>=0 && eRequired<=SQLITE_LOCK_EXCLUSIVE);
+      }
+    }
+
+    if( eRequired>pLock->eLock ){
+      rc = sqlite3OsLock(pLock->pFile, eRequired);
+      if( rc==SQLITE_OK ){
+        pLock->eLock = eRequired;
+      }
+    }
+    else if( eRequired<pLock->eLock && eRequired<=SQLITE_LOCK_SHARED ){
+      rc = sqlite3OsUnlock(pLock->pFile, eRequired);
+      if( rc==SQLITE_OK ){
+        pLock->eLock = eRequired;
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** The following two methods - asyncLock() and asyncUnlock() - are used
+** to obtain and release locks on database files opened with the
+** asynchronous backend.
+*/
+static int asyncLock(sqlite3_file *pFile, int eLock){
+  int rc = SQLITE_OK;
+  AsyncFileData *p = ((AsyncFile *)pFile)->pData;
+
+  pthread_mutex_lock(&async.lockMutex);
+  if( p->lock.eLock<eLock ){
+    AsyncLock *pLock;
+    AsyncFileLock *pIter;
+    pLock = (AsyncLock *)sqlite3HashFind(&async.aLock, p->zName, p->nName);
+    assert(pLock && pLock->pList);
+    for(pIter=pLock->pList; pIter; pIter=pIter->pNext){
+      if( pIter!=&p->lock && (
+        (eLock==SQLITE_LOCK_EXCLUSIVE && pIter->eLock>=SQLITE_LOCK_SHARED) ||
+        (eLock==SQLITE_LOCK_PENDING && pIter->eLock>=SQLITE_LOCK_RESERVED) ||
+        (eLock==SQLITE_LOCK_RESERVED && pIter->eLock>=SQLITE_LOCK_RESERVED) ||
+        (eLock==SQLITE_LOCK_SHARED && pIter->eLock>=SQLITE_LOCK_PENDING)
+      )){
+        rc = SQLITE_BUSY;
+      }
+    }
+    if( rc==SQLITE_OK ){
+      p->lock.eLock = eLock;
+      p->lock.eAsyncLock = MAX(p->lock.eAsyncLock, eLock);
+    }
+    assert(p->lock.eAsyncLock>=p->lock.eLock);
+    if( rc==SQLITE_OK ){
+      rc = getFileLock(pLock);
+    }
+  }
+  pthread_mutex_unlock(&async.lockMutex);
+
+  ASYNC_TRACE(("LOCK %d (%s) rc=%d\n", eLock, p->zName, rc));
+  return rc;
+}
+static int asyncUnlock(sqlite3_file *pFile, int eLock){
+  AsyncFileData *p = ((AsyncFile *)pFile)->pData;
+  AsyncFileLock *pLock = &p->lock;
+  pthread_mutex_lock(&async.lockMutex);
+  pLock->eLock = MIN(pLock->eLock, eLock);
+  pthread_mutex_unlock(&async.lockMutex);
+  return addNewAsyncWrite(p, ASYNC_UNLOCK, 0, eLock, 0);
+}
+
+/*
+** This function is called when the pager layer first opens a database file
+** and is checking for a hot-journal.
+*/
+static int asyncCheckReservedLock(sqlite3_file *pFile, int *pResOut){
+  int ret = 0;
+  AsyncFileLock *pIter;
+  AsyncLock *pLock;
+  AsyncFileData *p = ((AsyncFile *)pFile)->pData;
+
+  pthread_mutex_lock(&async.lockMutex);
+  pLock = (AsyncLock *)sqlite3HashFind(&async.aLock, p->zName, p->nName);
+  for(pIter=pLock->pList; pIter; pIter=pIter->pNext){
+    if( pIter->eLock>=SQLITE_LOCK_RESERVED ){
+      ret = 1;
+    }
+  }
+  pthread_mutex_unlock(&async.lockMutex);
+
+  ASYNC_TRACE(("CHECK-LOCK %d (%s)\n", ret, p->zName));
+  *pResOut = ret;
+  return SQLITE_OK;
+}
+
+/* 
+** This is a no-op, as the asynchronous backend does not support locking.
+*/
+static int asyncFileControl(sqlite3_file *id, int op, void *pArg){
+  switch( op ){
+    case SQLITE_FCNTL_LOCKSTATE: {
+      pthread_mutex_lock(&async.lockMutex);
+      *(int*)pArg = ((AsyncFile*)id)->pData->lock.eLock;
+      pthread_mutex_unlock(&async.lockMutex);
+      return SQLITE_OK;
+    }
+  }
+  return SQLITE_ERROR;
+}
+
+/* 
+** Return the device characteristics and sector-size of the device. It
+** is not tricky to implement these correctly, as this backend might 
+** not have an open file handle at this point.
+*/
+static int asyncSectorSize(sqlite3_file *pFile){
+  return 512;
+}
+static int asyncDeviceCharacteristics(sqlite3_file *pFile){
+  return 0;
+}
+
+static int unlinkAsyncFile(AsyncFileData *pData){
+  AsyncLock *pLock;
+  AsyncFileLock **ppIter;
+  int rc = SQLITE_OK;
+
+  pLock = sqlite3HashFind(&async.aLock, pData->zName, pData->nName);
+  for(ppIter=&pLock->pList; *ppIter; ppIter=&((*ppIter)->pNext)){
+    if( (*ppIter)==&pData->lock ){
+      *ppIter = pData->lock.pNext;
+      break;
+    }
+  }
+  if( !pLock->pList ){
+    if( pLock->pFile ){
+      sqlite3OsClose(pLock->pFile);
+    }
+    sqlite3_free(pLock);
+    sqlite3HashInsert(&async.aLock, pData->zName, pData->nName, 0);
+    if( !sqliteHashFirst(&async.aLock) ){
+      sqlite3HashClear(&async.aLock);
+    }
+  }else{
+    rc = getFileLock(pLock);
+  }
+
+  return rc;
+}
+
+/*
+** Open a file.
+*/
+static int asyncOpen(
+  sqlite3_vfs *pAsyncVfs,
+  const char *zName,
+  sqlite3_file *pFile,
+  int flags,
+  int *pOutFlags
+){
+  static sqlite3_io_methods async_methods = {
+    1,                               /* iVersion */
+    asyncClose,                      /* xClose */
+    asyncRead,                       /* xRead */
+    asyncWrite,                      /* xWrite */
+    asyncTruncate,                   /* xTruncate */
+    asyncSync,                       /* xSync */
+    asyncFileSize,                   /* xFileSize */
+    asyncLock,                       /* xLock */
+    asyncUnlock,                     /* xUnlock */
+    asyncCheckReservedLock,          /* xCheckReservedLock */
+    asyncFileControl,                /* xFileControl */
+    asyncSectorSize,                 /* xSectorSize */
+    asyncDeviceCharacteristics       /* xDeviceCharacteristics */
+  };
+
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
+  AsyncFile *p = (AsyncFile *)pFile;
+  int nName = strlen(zName)+1;
+  int rc = SQLITE_OK;
+  int nByte;
+  AsyncFileData *pData;
+  AsyncLock *pLock = 0;
+  char *z;
+  int isExclusive = (flags&SQLITE_OPEN_EXCLUSIVE);
+
+  nByte = (
+    sizeof(AsyncFileData) +        /* AsyncFileData structure */
+    2 * pVfs->szOsFile +           /* AsyncFileData.pBaseRead and pBaseWrite */
+    nName                          /* AsyncFileData.zName */
+  ); 
+  z = sqlite3_malloc(nByte);
+  if( !z ){
+    return SQLITE_NOMEM;
+  }
+  memset(z, 0, nByte);
+  pData = (AsyncFileData*)z;
+  z += sizeof(pData[0]);
+  pData->pBaseRead = (sqlite3_file*)z;
+  z += pVfs->szOsFile;
+  pData->pBaseWrite = (sqlite3_file*)z;
+  z += pVfs->szOsFile;
+  pData->zName = z;
+  pData->nName = nName;
+  pData->close.pFileData = pData;
+  pData->close.op = ASYNC_CLOSE;
+  memcpy(pData->zName, zName, nName);
+
+  if( !isExclusive ){
+    rc = sqlite3OsOpen(pVfs, zName, pData->pBaseRead, flags, pOutFlags);
+    if( rc==SQLITE_OK && ((*pOutFlags)&SQLITE_OPEN_READWRITE) ){
+      rc = sqlite3OsOpen(pVfs, zName, pData->pBaseWrite, flags, 0);
+    }
+  }
+
+  pthread_mutex_lock(&async.lockMutex);
+
+  if( rc==SQLITE_OK ){
+    pLock = sqlite3HashFind(&async.aLock, pData->zName, pData->nName);
+    if( !pLock ){
+      pLock = sqlite3MallocZero(pVfs->szOsFile + sizeof(AsyncLock));
+      if( pLock ){
+        AsyncLock *pDelete;
+#ifdef ENABLE_FILE_LOCKING
+        if( flags&SQLITE_OPEN_MAIN_DB ){
+          pLock->pFile = (sqlite3_file *)&pLock[1];
+          rc = sqlite3OsOpen(pVfs, zName, pLock->pFile, flags, 0);
+          if( rc!=SQLITE_OK ){
+            sqlite3_free(pLock);
+            pLock = 0;
+          }
+        }
+#endif
+        pDelete = sqlite3HashInsert(
+          &async.aLock, pData->zName, pData->nName, (void *)pLock
+        );
+        if( pDelete ){
+          rc = SQLITE_NOMEM;
+          sqlite3_free(pLock);
+        }
+      }else{
+        rc = SQLITE_NOMEM;
+      }
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    HashElem *pElem;
+    p->pMethod = &async_methods;
+    p->pData = pData;
+
+    /* Link AsyncFileData.lock into the linked list of 
+    ** AsyncFileLock structures for this file.
+    */
+    pData->lock.pNext = pLock->pList;
+    pLock->pList = &pData->lock;
+
+    pElem = sqlite3HashFindElem(&async.aLock, pData->zName, pData->nName);
+    pData->zName = (char *)sqliteHashKey(pElem);
+  }else{
+    sqlite3OsClose(pData->pBaseRead);
+    sqlite3OsClose(pData->pBaseWrite);
+    sqlite3_free(pData);
+  }
+
+  pthread_mutex_unlock(&async.lockMutex);
+
+  if( rc==SQLITE_OK ){
+    incrOpenFileCount();
+  }
+
+  if( rc==SQLITE_OK && isExclusive ){
+    rc = addNewAsyncWrite(pData, ASYNC_OPENEXCLUSIVE, (i64)flags, 0, 0);
+    if( rc==SQLITE_OK ){
+      if( pOutFlags ) *pOutFlags = flags;
+    }else{
+      pthread_mutex_lock(&async.lockMutex);
+      unlinkAsyncFile(pData);
+      pthread_mutex_unlock(&async.lockMutex);
+      sqlite3_free(pData);
+    }
+  }
+  return rc;
+}
+
+/*
+** Implementation of sqlite3OsDelete. Add an entry to the end of the 
+** write-op queue to perform the delete.
+*/
+static int asyncDelete(sqlite3_vfs *pAsyncVfs, const char *z, int syncDir){
+  return addNewAsyncWrite(0, ASYNC_DELETE, syncDir, strlen(z)+1, z);
+}
+
+/*
+** Implementation of sqlite3OsAccess. This method holds the mutex from
+** start to finish.
+*/
+static int asyncAccess(
+  sqlite3_vfs *pAsyncVfs, 
+  const char *zName, 
+  int flags,
+  int *pResOut
+){
+  int rc;
+  int ret;
+  AsyncWrite *p;
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
+
+  assert(flags==SQLITE_ACCESS_READWRITE 
+      || flags==SQLITE_ACCESS_READ 
+      || flags==SQLITE_ACCESS_EXISTS 
+  );
+
+  pthread_mutex_lock(&async.queueMutex);
+  rc = sqlite3OsAccess(pVfs, zName, flags, &ret);
+  if( rc==SQLITE_OK && flags==SQLITE_ACCESS_EXISTS ){
+    for(p=async.pQueueFirst; p; p = p->pNext){
+      if( p->op==ASYNC_DELETE && 0==strcmp(p->zBuf, zName) ){
+        ret = 0;
+      }else if( p->op==ASYNC_OPENEXCLUSIVE 
+             && 0==strcmp(p->pFileData->zName, zName) 
+      ){
+        ret = 1;
+      }
+    }
+  }
+  ASYNC_TRACE(("ACCESS(%s): %s = %d\n", 
+    flags==SQLITE_ACCESS_READWRITE?"read-write":
+    flags==SQLITE_ACCESS_READ?"read":"exists"
+    , zName, ret)
+  );
+  pthread_mutex_unlock(&async.queueMutex);
+  *pResOut = ret;
+  return rc;
+}
+
+/*
+** Fill in zPathOut with the full path to the file identified by zPath.
+*/
+static int asyncFullPathname(
+  sqlite3_vfs *pAsyncVfs, 
+  const char *zPath, 
+  int nPathOut,
+  char *zPathOut
+){
+  int rc;
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
+  rc = sqlite3OsFullPathname(pVfs, zPath, nPathOut, zPathOut);
+
+  /* Because of the way intra-process file locking works, this backend
+  ** needs to return a canonical path. The following block assumes the
+  ** file-system uses unix style paths. 
+  */
+  if( rc==SQLITE_OK ){
+    int iIn;
+    int iOut = 0;
+    int nPathOut = strlen(zPathOut);
+
+    for(iIn=0; iIn<nPathOut; iIn++){
+
+      /* Replace any occurences of "//" with "/" */
+      if( iIn<=(nPathOut-2) && zPathOut[iIn]=='/' && zPathOut[iIn+1]=='/'
+      ){
+        continue;
+      }
+
+      /* Replace any occurences of "/./" with "/" */
+      if( iIn<=(nPathOut-3) 
+       && zPathOut[iIn]=='/' && zPathOut[iIn+1]=='.' && zPathOut[iIn+2]=='/'
+      ){
+        iIn++;
+        continue;
+      }
+
+      /* Replace any occurences of "<path-component>/../" with "" */
+      if( iOut>0 && iIn<=(nPathOut-4) 
+       && zPathOut[iIn]=='/' && zPathOut[iIn+1]=='.' 
+       && zPathOut[iIn+2]=='.' && zPathOut[iIn+3]=='/'
+      ){
+        iIn += 3;
+        iOut--;
+        for( ; iOut>0 && zPathOut[iOut-1]!='/'; iOut--);
+        continue;
+      }
+
+      zPathOut[iOut++] = zPathOut[iIn];
+    }
+    zPathOut[iOut] = '\0';
+  }
+
+  return rc;
+}
+static void *asyncDlOpen(sqlite3_vfs *pAsyncVfs, const char *zPath){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
+  return pVfs->xDlOpen(pVfs, zPath);
+}
+static void asyncDlError(sqlite3_vfs *pAsyncVfs, int nByte, char *zErrMsg){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
+  pVfs->xDlError(pVfs, nByte, zErrMsg);
+}
+static void *asyncDlSym(
+  sqlite3_vfs *pAsyncVfs, 
+  void *pHandle, 
+  const char *zSymbol
+){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
+  return pVfs->xDlSym(pVfs, pHandle, zSymbol);
+}
+static void asyncDlClose(sqlite3_vfs *pAsyncVfs, void *pHandle){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
+  pVfs->xDlClose(pVfs, pHandle);
+}
+static int asyncRandomness(sqlite3_vfs *pAsyncVfs, int nByte, char *zBufOut){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
+  return pVfs->xRandomness(pVfs, nByte, zBufOut);
+}
+static int asyncSleep(sqlite3_vfs *pAsyncVfs, int nMicro){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
+  return pVfs->xSleep(pVfs, nMicro);
+}
+static int asyncCurrentTime(sqlite3_vfs *pAsyncVfs, double *pTimeOut){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
+  return pVfs->xCurrentTime(pVfs, pTimeOut);
+}
+
+static sqlite3_vfs async_vfs = {
+  1,                    /* iVersion */
+  sizeof(AsyncFile),    /* szOsFile */
+  0,                    /* mxPathname */
+  0,                    /* pNext */
+  "async",              /* zName */
+  0,                    /* pAppData */
+  asyncOpen,            /* xOpen */
+  asyncDelete,          /* xDelete */
+  asyncAccess,          /* xAccess */
+  asyncFullPathname,    /* xFullPathname */
+  asyncDlOpen,          /* xDlOpen */
+  asyncDlError,         /* xDlError */
+  asyncDlSym,           /* xDlSym */
+  asyncDlClose,         /* xDlClose */
+  asyncRandomness,      /* xDlError */
+  asyncSleep,           /* xDlSym */
+  asyncCurrentTime      /* xDlClose */
+};
+
+/*
+** Call this routine to enable or disable the
+** asynchronous IO features implemented in this file. 
+**
+** This routine is not even remotely threadsafe.  Do not call
+** this routine while any SQLite database connections are open.
+*/
+static void asyncEnable(int enable){
+  if( enable ){
+    if( !async_vfs.pAppData ){
+      static int hashTableInit = 0;
+      async_vfs.pAppData = (void *)sqlite3_vfs_find(0);
+      async_vfs.mxPathname = ((sqlite3_vfs *)async_vfs.pAppData)->mxPathname;
+      sqlite3_vfs_register(&async_vfs, 1);
+      if( !hashTableInit ){
+        sqlite3HashInit(&async.aLock, SQLITE_HASH_BINARY, 1);
+        hashTableInit = 1;
+      }
+    }
+  }else{
+    if( async_vfs.pAppData ){
+      sqlite3_vfs_unregister(&async_vfs);
+      async_vfs.pAppData = 0;
+    }
+  }
+}
+
+/* 
+** This procedure runs in a separate thread, reading messages off of the
+** write queue and processing them one by one.  
+**
+** If async.writerHaltNow is true, then this procedure exits
+** after processing a single message.
+**
+** If async.writerHaltWhenIdle is true, then this procedure exits when
+** the write queue is empty.
+**
+** If both of the above variables are false, this procedure runs
+** indefinately, waiting for operations to be added to the write queue
+** and processing them in the order in which they arrive.
+**
+** An artifical delay of async.ioDelay milliseconds is inserted before
+** each write operation in order to simulate the effect of a slow disk.
+**
+** Only one instance of this procedure may be running at a time.
+*/
+static void *asyncWriterThread(void *pIsStarted){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)(async_vfs.pAppData);
+  AsyncWrite *p = 0;
+  int rc = SQLITE_OK;
+  int holdingMutex = 0;
+
+  if( pthread_mutex_trylock(&async.writerMutex) ){
+    return 0;
+  }
+  (*(int *)pIsStarted) = 1;
+  while( async.writerHaltNow==0 ){
+    int doNotFree = 0;
+    sqlite3_file *pBase = 0;
+
+    if( !holdingMutex ){
+      pthread_mutex_lock(&async.queueMutex);
+    }
+    while( (p = async.pQueueFirst)==0 ){
+      pthread_cond_broadcast(&async.emptySignal);
+      if( async.writerHaltWhenIdle ){
+        pthread_mutex_unlock(&async.queueMutex);
+        break;
+      }else{
+        ASYNC_TRACE(("IDLE\n"));
+        pthread_cond_wait(&async.queueSignal, &async.queueMutex);
+        ASYNC_TRACE(("WAKEUP\n"));
+      }
+    }
+    if( p==0 ) break;
+    holdingMutex = 1;
+
+    /* Right now this thread is holding the mutex on the write-op queue.
+    ** Variable 'p' points to the first entry in the write-op queue. In
+    ** the general case, we hold on to the mutex for the entire body of
+    ** the loop. 
+    **
+    ** However in the cases enumerated below, we relinquish the mutex,
+    ** perform the IO, and then re-request the mutex before removing 'p' from
+    ** the head of the write-op queue. The idea is to increase concurrency with
+    ** sqlite threads.
+    **
+    **     * An ASYNC_CLOSE operation.
+    **     * An ASYNC_OPENEXCLUSIVE operation. For this one, we relinquish 
+    **       the mutex, call the underlying xOpenExclusive() function, then
+    **       re-aquire the mutex before seting the AsyncFile.pBaseRead 
+    **       variable.
+    **     * ASYNC_SYNC and ASYNC_WRITE operations, if 
+    **       SQLITE_ASYNC_TWO_FILEHANDLES was set at compile time and two
+    **       file-handles are open for the particular file being "synced".
+    */
+    if( async.ioError!=SQLITE_OK && p->op!=ASYNC_CLOSE ){
+      p->op = ASYNC_NOOP;
+    }
+    if( p->pFileData ){
+      pBase = p->pFileData->pBaseWrite;
+      if( 
+        p->op==ASYNC_CLOSE || 
+        p->op==ASYNC_OPENEXCLUSIVE ||
+        (pBase->pMethods && (p->op==ASYNC_SYNC || p->op==ASYNC_WRITE) ) 
+      ){
+        pthread_mutex_unlock(&async.queueMutex);
+        holdingMutex = 0;
+      }
+      if( !pBase->pMethods ){
+        pBase = p->pFileData->pBaseRead;
+      }
+    }
+
+    switch( p->op ){
+      case ASYNC_NOOP:
+        break;
+
+      case ASYNC_WRITE:
+        assert( pBase );
+        ASYNC_TRACE(("WRITE %s %d bytes at %d\n",
+                p->pFileData->zName, p->nByte, p->iOffset));
+        rc = sqlite3OsWrite(pBase, (void *)(p->zBuf), p->nByte, p->iOffset);
+        break;
+
+      case ASYNC_SYNC:
+        assert( pBase );
+        ASYNC_TRACE(("SYNC %s\n", p->pFileData->zName));
+        rc = sqlite3OsSync(pBase, p->nByte);
+        break;
+
+      case ASYNC_TRUNCATE:
+        assert( pBase );
+        ASYNC_TRACE(("TRUNCATE %s to %d bytes\n", 
+                p->pFileData->zName, p->iOffset));
+        rc = sqlite3OsTruncate(pBase, p->iOffset);
+        break;
+
+      case ASYNC_CLOSE: {
+        AsyncFileData *pData = p->pFileData;
+        ASYNC_TRACE(("CLOSE %s\n", p->pFileData->zName));
+        sqlite3OsClose(pData->pBaseWrite);
+        sqlite3OsClose(pData->pBaseRead);
+
+        /* Unlink AsyncFileData.lock from the linked list of AsyncFileLock 
+        ** structures for this file. Obtain the async.lockMutex mutex 
+        ** before doing so.
+        */
+        pthread_mutex_lock(&async.lockMutex);
+        rc = unlinkAsyncFile(pData);
+        pthread_mutex_unlock(&async.lockMutex);
+
+        async.pQueueFirst = p->pNext;
+        sqlite3_free(pData);
+        doNotFree = 1;
+        break;
+      }
+
+      case ASYNC_UNLOCK: {
+        AsyncLock *pLock;
+        AsyncFileData *pData = p->pFileData;
+        int eLock = p->nByte;
+        pthread_mutex_lock(&async.lockMutex);
+        pData->lock.eAsyncLock = MIN(
+            pData->lock.eAsyncLock, MAX(pData->lock.eLock, eLock)
+        );
+        assert(pData->lock.eAsyncLock>=pData->lock.eLock);
+        pLock = sqlite3HashFind(&async.aLock, pData->zName, pData->nName);
+        rc = getFileLock(pLock);
+        pthread_mutex_unlock(&async.lockMutex);
+        break;
+      }
+
+      case ASYNC_DELETE:
+        ASYNC_TRACE(("DELETE %s\n", p->zBuf));
+        rc = sqlite3OsDelete(pVfs, p->zBuf, (int)p->iOffset);
+        break;
+
+      case ASYNC_OPENEXCLUSIVE: {
+        int flags = (int)p->iOffset;
+        AsyncFileData *pData = p->pFileData;
+        ASYNC_TRACE(("OPEN %s flags=%d\n", p->zBuf, (int)p->iOffset));
+        assert(pData->pBaseRead->pMethods==0 && pData->pBaseWrite->pMethods==0);
+        rc = sqlite3OsOpen(pVfs, pData->zName, pData->pBaseRead, flags, 0);
+        assert( holdingMutex==0 );
+        pthread_mutex_lock(&async.queueMutex);
+        holdingMutex = 1;
+        break;
+      }
+
+      default: assert(!"Illegal value for AsyncWrite.op");
+    }
+
+    /* If we didn't hang on to the mutex during the IO op, obtain it now
+    ** so that the AsyncWrite structure can be safely removed from the 
+    ** global write-op queue.
+    */
+    if( !holdingMutex ){
+      pthread_mutex_lock(&async.queueMutex);
+      holdingMutex = 1;
+    }
+    /* ASYNC_TRACE(("UNLINK %p\n", p)); */
+    if( p==async.pQueueLast ){
+      async.pQueueLast = 0;
+    }
+    if( !doNotFree ){
+      async.pQueueFirst = p->pNext;
+      sqlite3_free(p);
+    }
+    assert( holdingMutex );
+
+    /* An IO error has occured. We cannot report the error back to the
+    ** connection that requested the I/O since the error happened 
+    ** asynchronously.  The connection has already moved on.  There 
+    ** really is nobody to report the error to.
+    **
+    ** The file for which the error occured may have been a database or
+    ** journal file. Regardless, none of the currently queued operations
+    ** associated with the same database should now be performed. Nor should
+    ** any subsequently requested IO on either a database or journal file 
+    ** handle for the same database be accepted until the main database
+    ** file handle has been closed and reopened.
+    **
+    ** Furthermore, no further IO should be queued or performed on any file
+    ** handle associated with a database that may have been part of a 
+    ** multi-file transaction that included the database associated with 
+    ** the IO error (i.e. a database ATTACHed to the same handle at some 
+    ** point in time).
+    */
+    if( rc!=SQLITE_OK ){
+      async.ioError = rc;
+    }
+
+    if( async.ioError && !async.pQueueFirst ){
+      pthread_mutex_lock(&async.lockMutex);
+      if( 0==sqliteHashFirst(&async.aLock) ){
+        async.ioError = SQLITE_OK;
+      }
+      pthread_mutex_unlock(&async.lockMutex);
+    }
+
+    /* Drop the queue mutex before continuing to the next write operation
+    ** in order to give other threads a chance to work with the write queue.
+    */
+    if( !async.pQueueFirst || !async.ioError ){
+      pthread_mutex_unlock(&async.queueMutex);
+      holdingMutex = 0;
+      if( async.ioDelay>0 ){
+        sqlite3OsSleep(pVfs, async.ioDelay);
+      }else{
+        sched_yield();
+      }
+    }
+  }
+  
+  pthread_mutex_unlock(&async.writerMutex);
+  return 0;
+}
+
+/**************************************************************************
+** The remaining code defines a Tcl interface for testing the asynchronous
+** IO implementation in this file.
+**
+** To adapt the code to a non-TCL environment, delete or comment out
+** the code that follows.
+*/
+
+/*
+** sqlite3async_enable ?YES/NO?
+**
+** Enable or disable the asynchronous I/O backend.  This command is
+** not thread-safe.  Do not call it while any database connections
+** are open.
+*/
+static int testAsyncEnable(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  if( objc!=1 && objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "?YES/NO?");
+    return TCL_ERROR;
+  }
+  if( objc==1 ){
+    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(async_vfs.pAppData!=0));
+  }else{
+    int en;
+    if( Tcl_GetBooleanFromObj(interp, objv[1], &en) ) return TCL_ERROR;
+    asyncEnable(en);
+  }
+  return TCL_OK;
+}
+
+/*
+** sqlite3async_halt  "now"|"idle"|"never"
+**
+** Set the conditions at which the writer thread will halt.
+*/
+static int testAsyncHalt(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  const char *zCond;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "\"now\"|\"idle\"|\"never\"");
+    return TCL_ERROR;
+  }
+  zCond = Tcl_GetString(objv[1]);
+  if( strcmp(zCond, "now")==0 ){
+    async.writerHaltNow = 1;
+    pthread_cond_broadcast(&async.queueSignal);
+  }else if( strcmp(zCond, "idle")==0 ){
+    async.writerHaltWhenIdle = 1;
+    async.writerHaltNow = 0;
+    pthread_cond_broadcast(&async.queueSignal);
+  }else if( strcmp(zCond, "never")==0 ){
+    async.writerHaltWhenIdle = 0;
+    async.writerHaltNow = 0;
+  }else{
+    Tcl_AppendResult(interp, 
+      "should be one of: \"now\", \"idle\", or \"never\"", (char*)0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+
+/*
+** sqlite3async_delay ?MS?
+**
+** Query or set the number of milliseconds of delay in the writer
+** thread after each write operation.  The default is 0.  By increasing
+** the memory delay we can simulate the effect of slow disk I/O.
+*/
+static int testAsyncDelay(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  if( objc!=1 && objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "?MS?");
+    return TCL_ERROR;
+  }
+  if( objc==1 ){
+    Tcl_SetObjResult(interp, Tcl_NewIntObj(async.ioDelay));
+  }else{
+    int ioDelay;
+    if( Tcl_GetIntFromObj(interp, objv[1], &ioDelay) ) return TCL_ERROR;
+    async.ioDelay = ioDelay;
+  }
+  return TCL_OK;
+}
+
+/*
+** sqlite3async_start
+**
+** Start a new writer thread.
+*/
+static int testAsyncStart(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  pthread_t x;
+  int rc;
+  volatile int isStarted = 0;
+  rc = pthread_create(&x, 0, asyncWriterThread, (void *)&isStarted);
+  if( rc ){
+    Tcl_AppendResult(interp, "failed to create the thread", 0);
+    return TCL_ERROR;
+  }
+  pthread_detach(x);
+  while( isStarted==0 ){
+    sched_yield();
+  }
+  return TCL_OK;
+}
+
+/*
+** sqlite3async_wait
+**
+** Wait for the current writer thread to terminate.
+**
+** If the current writer thread is set to run forever then this
+** command would block forever.  To prevent that, an error is returned. 
+*/
+static int testAsyncWait(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int cnt = 10;
+  if( async.writerHaltNow==0 && async.writerHaltWhenIdle==0 ){
+    Tcl_AppendResult(interp, "would block forever", (char*)0);
+    return TCL_ERROR;
+  }
+
+  while( cnt-- && !pthread_mutex_trylock(&async.writerMutex) ){
+    pthread_mutex_unlock(&async.writerMutex);
+    sched_yield();
+  }
+  if( cnt>=0 ){
+    ASYNC_TRACE(("WAIT\n"));
+    pthread_mutex_lock(&async.queueMutex);
+    pthread_cond_broadcast(&async.queueSignal);
+    pthread_mutex_unlock(&async.queueMutex);
+    pthread_mutex_lock(&async.writerMutex);
+    pthread_mutex_unlock(&async.writerMutex);
+  }else{
+    ASYNC_TRACE(("NO-WAIT\n"));
+  }
+  return TCL_OK;
+}
+
+
+#endif  /* SQLITE_OS_UNIX and SQLITE_THREADSAFE */
+
+/*
+** This routine registers the custom TCL commands defined in this
+** module.  This should be the only procedure visible from outside
+** of this module.
+*/
+int Sqlitetestasync_Init(Tcl_Interp *interp){
+#if SQLITE_OS_UNIX && SQLITE_THREADSAFE
+  Tcl_CreateObjCommand(interp,"sqlite3async_enable",testAsyncEnable,0,0);
+  Tcl_CreateObjCommand(interp,"sqlite3async_halt",testAsyncHalt,0,0);
+  Tcl_CreateObjCommand(interp,"sqlite3async_delay",testAsyncDelay,0,0);
+  Tcl_CreateObjCommand(interp,"sqlite3async_start",testAsyncStart,0,0);
+  Tcl_CreateObjCommand(interp,"sqlite3async_wait",testAsyncWait,0,0);
+  Tcl_LinkVar(interp, "sqlite3async_trace",
+      (char*)&sqlite3async_trace, TCL_LINK_INT);
+#endif  /* SQLITE_OS_UNIX and SQLITE_THREADSAFE */
+  return TCL_OK;
+}
diff --git a/third_party/sqlite/src/test_autoext.c b/third_party/sqlite/src/test_autoext.c
new file mode 100755
index 0000000..11f5413
--- /dev/null
+++ b/third_party/sqlite/src/test_autoext.c
@@ -0,0 +1,169 @@
+/*
+** 2006 August 23
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Test extension for testing the sqlite3_auto_extension() function.
+**
+** $Id: test_autoext.c,v 1.5 2008/07/08 02:12:37 drh Exp $
+*/
+#include "tcl.h"
+#include "sqlite3ext.h"
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+static SQLITE_EXTENSION_INIT1
+
+/*
+** The sqr() SQL function returns the square of its input value.
+*/
+static void sqrFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  double r = sqlite3_value_double(argv[0]);
+  sqlite3_result_double(context, r*r);
+}
+
+/*
+** This is the entry point to register the extension for the sqr() function.
+*/
+static int sqr_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi);
+  sqlite3_create_function(db, "sqr", 1, SQLITE_ANY, 0, sqrFunc, 0, 0);
+  return 0;
+}
+
+/*
+** The cube() SQL function returns the cube of its input value.
+*/
+static void cubeFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  double r = sqlite3_value_double(argv[0]);
+  sqlite3_result_double(context, r*r*r);
+}
+
+/*
+** This is the entry point to register the extension for the cube() function.
+*/
+static int cube_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi);
+  sqlite3_create_function(db, "cube", 1, SQLITE_ANY, 0, cubeFunc, 0, 0);
+  return 0;
+}
+
+/*
+** This is a broken extension entry point
+*/
+static int broken_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  char *zErr;
+  SQLITE_EXTENSION_INIT2(pApi);
+  zErr = sqlite3_mprintf("broken autoext!");
+  *pzErrMsg = zErr;
+  return 1;
+}
+
+/*
+** tclcmd:   sqlite3_auto_extension_sqr
+**
+** Register the "sqr" extension to be loaded automatically.
+*/
+static int autoExtSqrObjCmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc = sqlite3_auto_extension((void*)sqr_init);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return SQLITE_OK;
+}
+
+/*
+** tclcmd:   sqlite3_auto_extension_cube
+**
+** Register the "cube" extension to be loaded automatically.
+*/
+static int autoExtCubeObjCmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc = sqlite3_auto_extension((void*)cube_init);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return SQLITE_OK;
+}
+
+/*
+** tclcmd:   sqlite3_auto_extension_broken
+**
+** Register the broken extension to be loaded automatically.
+*/
+static int autoExtBrokenObjCmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc = sqlite3_auto_extension((void*)broken_init);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return SQLITE_OK;
+}
+
+#endif /* SQLITE_OMIT_LOAD_EXTENSION */
+
+
+/*
+** tclcmd:   sqlite3_reset_auto_extension
+**
+** Reset all auto-extensions
+*/
+static int resetAutoExtObjCmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_reset_auto_extension();
+  return SQLITE_OK;
+}
+
+
+/*
+** This procedure registers the TCL procs defined in this file.
+*/
+int Sqlitetest_autoext_Init(Tcl_Interp *interp){
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+  Tcl_CreateObjCommand(interp, "sqlite3_auto_extension_sqr",
+          autoExtSqrObjCmd, 0, 0);
+  Tcl_CreateObjCommand(interp, "sqlite3_auto_extension_cube",
+          autoExtCubeObjCmd, 0, 0);
+  Tcl_CreateObjCommand(interp, "sqlite3_auto_extension_broken",
+          autoExtBrokenObjCmd, 0, 0);
+#endif
+  Tcl_CreateObjCommand(interp, "sqlite3_reset_auto_extension",
+          resetAutoExtObjCmd, 0, 0);
+  return TCL_OK;
+}
diff --git a/third_party/sqlite/src/test_btree.c b/third_party/sqlite/src/test_btree.c
new file mode 100755
index 0000000..006df81
--- /dev/null
+++ b/third_party/sqlite/src/test_btree.c
@@ -0,0 +1,140 @@
+/*
+** 2007 May 05
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing the btree.c module in SQLite.  This code
+** is not included in the SQLite library.  It is used for automated
+** testing of the SQLite library.
+**
+** $Id: test_btree.c,v 1.6 2008/07/15 00:27:35 drh Exp $
+*/
+#include "btreeInt.h"
+#include <tcl.h>
+
+/*
+** Usage: sqlite3_shared_cache_report
+**
+** Return a list of file that are shared and the number of
+** references to each file.
+*/
+int sqlite3BtreeSharedCacheReport(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  extern BtShared *sqlite3SharedCacheList;
+  BtShared *pBt;
+  Tcl_Obj *pRet = Tcl_NewObj();
+  for(pBt=sqlite3SharedCacheList; pBt; pBt=pBt->pNext){
+    const char *zFile = sqlite3PagerFilename(pBt->pPager);
+    Tcl_ListObjAppendElement(interp, pRet, Tcl_NewStringObj(zFile, -1));
+    Tcl_ListObjAppendElement(interp, pRet, Tcl_NewIntObj(pBt->nRef));
+  }
+  Tcl_SetObjResult(interp, pRet);
+#endif
+  return TCL_OK;
+}
+
+/*
+** Print debugging information about all cursors to standard output.
+*/
+void sqlite3BtreeCursorList(Btree *p){
+#ifdef SQLITE_DEBUG
+  BtCursor *pCur;
+  BtShared *pBt = p->pBt;
+  for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
+    MemPage *pPage = pCur->pPage;
+    char *zMode = pCur->wrFlag ? "rw" : "ro";
+    sqlite3DebugPrintf("CURSOR %p rooted at %4d(%s) currently at %d.%d%s\n",
+       pCur, pCur->pgnoRoot, zMode,
+       pPage ? pPage->pgno : 0, pCur->idx,
+       (pCur->eState==CURSOR_VALID) ? "" : " eof"
+    );
+  }
+#endif
+}
+
+
+/*
+** Fill aResult[] with information about the entry and page that the
+** cursor is pointing to.
+** 
+**   aResult[0] =  The page number
+**   aResult[1] =  The entry number
+**   aResult[2] =  Total number of entries on this page
+**   aResult[3] =  Cell size (local payload + header)
+**   aResult[4] =  Number of free bytes on this page
+**   aResult[5] =  Number of free blocks on the page
+**   aResult[6] =  Total payload size (local + overflow)
+**   aResult[7] =  Header size in bytes
+**   aResult[8] =  Local payload size
+**   aResult[9] =  Parent page number
+**   aResult[10]=  Page number of the first overflow page
+**
+** This routine is used for testing and debugging only.
+*/
+int sqlite3BtreeCursorInfo(BtCursor *pCur, int *aResult, int upCnt){
+  int cnt, idx;
+  MemPage *pPage = pCur->pPage;
+  BtCursor tmpCur;
+  int rc;
+
+  if( pCur->eState==CURSOR_REQUIRESEEK ){
+    rc = sqlite3BtreeRestoreCursorPosition(pCur);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+  }
+
+  assert( pPage->isInit );
+  sqlite3BtreeGetTempCursor(pCur, &tmpCur);
+  while( upCnt-- ){
+    sqlite3BtreeMoveToParent(&tmpCur);
+  }
+  pPage = tmpCur.pPage;
+  aResult[0] = sqlite3PagerPagenumber(pPage->pDbPage);
+  assert( aResult[0]==pPage->pgno );
+  aResult[1] = tmpCur.idx;
+  aResult[2] = pPage->nCell;
+  if( tmpCur.idx>=0 && tmpCur.idx<pPage->nCell ){
+    sqlite3BtreeParseCell(tmpCur.pPage, tmpCur.idx, &tmpCur.info);
+    aResult[3] = tmpCur.info.nSize;
+    aResult[6] = tmpCur.info.nData;
+    aResult[7] = tmpCur.info.nHeader;
+    aResult[8] = tmpCur.info.nLocal;
+  }else{
+    aResult[3] = 0;
+    aResult[6] = 0;
+    aResult[7] = 0;
+    aResult[8] = 0;
+  }
+  aResult[4] = pPage->nFree;
+  cnt = 0;
+  idx = get2byte(&pPage->aData[pPage->hdrOffset+1]);
+  while( idx>0 && idx<pPage->pBt->usableSize ){
+    cnt++;
+    idx = get2byte(&pPage->aData[idx]);
+  }
+  aResult[5] = cnt;
+  if( pPage->pParent==0 || sqlite3BtreeIsRootPage(pPage) ){
+    aResult[9] = 0;
+  }else{
+    aResult[9] = pPage->pParent->pgno;
+  }
+  if( tmpCur.info.iOverflow ){
+    aResult[10] = get4byte(&tmpCur.info.pCell[tmpCur.info.iOverflow]);
+  }else{
+    aResult[10] = 0;
+  }
+  sqlite3BtreeReleaseTempCursor(&tmpCur);
+  return SQLITE_OK;
+}
diff --git a/third_party/sqlite/src/test_config.c b/third_party/sqlite/src/test_config.c
new file mode 100755
index 0000000..fe96b29
--- /dev/null
+++ b/third_party/sqlite/src/test_config.c
@@ -0,0 +1,488 @@
+/*
+** 2007 May 7
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** 
+** This file contains code used for testing the SQLite system.
+** None of the code in this file goes into a deliverable build.
+** 
+** The focus of this file is providing the TCL testing layer
+** access to compile-time constants.
+**
+** $Id: test_config.c,v 1.33 2008/07/31 02:05:05 shane Exp $
+*/
+
+#include "sqliteLimit.h"
+
+#include "sqliteInt.h"
+#include "tcl.h"
+#include <stdlib.h>
+#include <string.h>
+
+/*
+** This routine sets entries in the global ::sqlite_options() array variable
+** according to the compile-time configuration of the database.  Test
+** procedures use this to determine when tests should be omitted.
+*/
+static void set_options(Tcl_Interp *interp){
+  int rc = 0;
+
+#ifdef SQLITE_32BIT_ROWID
+  Tcl_SetVar2(interp, "sqlite_options", "rowid32", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "rowid32", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_CASE_SENSITIVE_LIKE
+  Tcl_SetVar2(interp, "sqlite_options","casesensitivelike","1",TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options","casesensitivelike","0",TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_DEBUG
+  Tcl_SetVar2(interp, "sqlite_options", "debug", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "debug", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_DISABLE_DIRSYNC
+  Tcl_SetVar2(interp, "sqlite_options", "dirsync", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "dirsync", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_DISABLE_LFS
+  Tcl_SetVar2(interp, "sqlite_options", "lfs", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "lfs", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#if 1 /* def SQLITE_MEMDEBUG */
+  Tcl_SetVar2(interp, "sqlite_options", "memdebug", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "memdebug", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_ENABLE_MEMSYS3
+  Tcl_SetVar2(interp, "sqlite_options", "mem3", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "mem3", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_ENABLE_MEMSYS5
+  Tcl_SetVar2(interp, "sqlite_options", "mem5", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "mem5", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_ALTERTABLE
+  Tcl_SetVar2(interp, "sqlite_options", "altertable", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "altertable", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_ANALYZE
+  Tcl_SetVar2(interp, "sqlite_options", "analyze", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "analyze", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+  Tcl_SetVar2(interp, "sqlite_options", "atomicwrite", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "atomicwrite", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_ATTACH
+  Tcl_SetVar2(interp, "sqlite_options", "attach", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "attach", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_AUTHORIZATION
+  Tcl_SetVar2(interp, "sqlite_options", "auth", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "auth", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_AUTOINCREMENT
+  Tcl_SetVar2(interp, "sqlite_options", "autoinc", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "autoinc", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_AUTOVACUUM
+  Tcl_SetVar2(interp, "sqlite_options", "autovacuum", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "autovacuum", "1", TCL_GLOBAL_ONLY);
+#endif /* SQLITE_OMIT_AUTOVACUUM */
+#if !defined(SQLITE_DEFAULT_AUTOVACUUM) || SQLITE_DEFAULT_AUTOVACUUM==0
+  Tcl_SetVar2(interp,"sqlite_options","default_autovacuum","0",TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp,"sqlite_options","default_autovacuum","1",TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_BETWEEN_OPTIMIZATION
+  Tcl_SetVar2(interp, "sqlite_options", "between_opt", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "between_opt", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_BUILTIN_TEST
+  Tcl_SetVar2(interp, "sqlite_options", "builtin_test", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "builtin_test", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_BLOB_LITERAL
+  Tcl_SetVar2(interp, "sqlite_options", "bloblit", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "bloblit", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_CAST
+  Tcl_SetVar2(interp, "sqlite_options", "cast", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "cast", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_CHECK
+  Tcl_SetVar2(interp, "sqlite_options", "check", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "check", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+  Tcl_SetVar2(interp, "sqlite_options", "columnmetadata", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "columnmetadata", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_COMPLETE
+  Tcl_SetVar2(interp, "sqlite_options", "complete", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "complete", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_COMPOUND_SELECT
+  Tcl_SetVar2(interp, "sqlite_options", "compound", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "compound", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_CONFLICT_CLAUSE
+  Tcl_SetVar2(interp, "sqlite_options", "conflict", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "conflict", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#if SQLITE_OS_UNIX
+  Tcl_SetVar2(interp, "sqlite_options", "crashtest", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "crashtest", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_DATETIME_FUNCS
+  Tcl_SetVar2(interp, "sqlite_options", "datetime", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "datetime", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_DECLTYPE
+  Tcl_SetVar2(interp, "sqlite_options", "decltype", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "decltype", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_DISKIO
+  Tcl_SetVar2(interp, "sqlite_options", "diskio", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "diskio", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_EXPLAIN
+  Tcl_SetVar2(interp, "sqlite_options", "explain", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "explain", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_FLOATING_POINT
+  Tcl_SetVar2(interp, "sqlite_options", "floatingpoint", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "floatingpoint", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_FOREIGN_KEY
+  Tcl_SetVar2(interp, "sqlite_options", "foreignkey", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "foreignkey", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_ENABLE_FTS1
+  Tcl_SetVar2(interp, "sqlite_options", "fts1", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "fts1", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_ENABLE_FTS2
+  Tcl_SetVar2(interp, "sqlite_options", "fts2", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "fts2", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_ENABLE_FTS3
+  Tcl_SetVar2(interp, "sqlite_options", "fts3", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "fts3", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_GET_TABLE
+  Tcl_SetVar2(interp, "sqlite_options", "gettable", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "gettable", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_GLOBALRECOVER
+  Tcl_SetVar2(interp, "sqlite_options", "globalrecover", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "globalrecover", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_ENABLE_ICU
+  Tcl_SetVar2(interp, "sqlite_options", "icu", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "icu", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_INCRBLOB
+  Tcl_SetVar2(interp, "sqlite_options", "incrblob", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "incrblob", "1", TCL_GLOBAL_ONLY);
+#endif /* SQLITE_OMIT_AUTOVACUUM */
+
+#ifdef SQLITE_OMIT_INTEGRITY_CHECK
+  Tcl_SetVar2(interp, "sqlite_options", "integrityck", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "integrityck", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#if defined(SQLITE_DEFAULT_FILE_FORMAT) && SQLITE_DEFAULT_FILE_FORMAT==1
+  Tcl_SetVar2(interp, "sqlite_options", "legacyformat", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "legacyformat", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_LIKE_OPTIMIZATION
+  Tcl_SetVar2(interp, "sqlite_options", "like_opt", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "like_opt", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_LOAD_EXTENSION
+  Tcl_SetVar2(interp, "sqlite_options", "load_ext", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "load_ext", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_LOCALTIME
+  Tcl_SetVar2(interp, "sqlite_options", "localtime", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "localtime", "1", TCL_GLOBAL_ONLY);
+#endif
+
+Tcl_SetVar2(interp, "sqlite_options", "long_double",
+              sizeof(LONGDOUBLE_TYPE)>sizeof(double) ? "1" : "0",
+              TCL_GLOBAL_ONLY);
+
+#ifdef SQLITE_OMIT_MEMORYDB
+  Tcl_SetVar2(interp, "sqlite_options", "memorydb", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "memorydb", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  Tcl_SetVar2(interp, "sqlite_options", "memorymanage", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "memorymanage", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_OR_OPTIMIZATION
+  Tcl_SetVar2(interp, "sqlite_options", "or_opt", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "or_opt", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_PAGER_PRAGMAS
+  Tcl_SetVar2(interp, "sqlite_options", "pager_pragmas", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "pager_pragmas", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_PARSER
+  Tcl_SetVar2(interp, "sqlite_options", "parser", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "parser", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#if defined(SQLITE_OMIT_PRAGMA) || defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  Tcl_SetVar2(interp, "sqlite_options", "pragma", "0", TCL_GLOBAL_ONLY);
+  Tcl_SetVar2(interp, "sqlite_options", "integrityck", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "pragma", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_PROGRESS_CALLBACK
+  Tcl_SetVar2(interp, "sqlite_options", "progress", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "progress", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_REINDEX
+  Tcl_SetVar2(interp, "sqlite_options", "reindex", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "reindex", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_ENABLE_RTREE
+  Tcl_SetVar2(interp, "sqlite_options", "rtree", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "rtree", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_SCHEMA_PRAGMAS
+  Tcl_SetVar2(interp, "sqlite_options", "schema_pragmas", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "schema_pragmas", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
+  Tcl_SetVar2(interp, "sqlite_options", "schema_version", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "schema_version", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_SHARED_CACHE
+  Tcl_SetVar2(interp, "sqlite_options", "shared_cache", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "shared_cache", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_SUBQUERY
+  Tcl_SetVar2(interp, "sqlite_options", "subquery", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "subquery", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_TCL_VARIABLE
+  Tcl_SetVar2(interp, "sqlite_options", "tclvar", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "tclvar", "1", TCL_GLOBAL_ONLY);
+#endif
+
+  rc = sqlite3_threadsafe();
+#if SQLITE_THREADSAFE
+  Tcl_SetVar2(interp, "sqlite_options", "threadsafe", "1", TCL_GLOBAL_ONLY);
+  assert( rc );
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "threadsafe", "0", TCL_GLOBAL_ONLY);
+  assert( !rc );
+#endif
+
+#ifdef SQLITE_OMIT_TRACE
+  Tcl_SetVar2(interp, "sqlite_options", "trace", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "trace", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_TRIGGER
+  Tcl_SetVar2(interp, "sqlite_options", "trigger", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "trigger", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_TEMPDB
+  Tcl_SetVar2(interp, "sqlite_options", "tempdb", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "tempdb", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_UTF16
+  Tcl_SetVar2(interp, "sqlite_options", "utf16", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "utf16", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#if defined(SQLITE_OMIT_VACUUM) || defined(SQLITE_OMIT_ATTACH)
+  Tcl_SetVar2(interp, "sqlite_options", "vacuum", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "vacuum", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_VIEW
+  Tcl_SetVar2(interp, "sqlite_options", "view", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "view", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_OMIT_VIRTUALTABLE
+  Tcl_SetVar2(interp, "sqlite_options", "vtab", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "vtab", "1", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef SQLITE_SECURE_DELETE
+  Tcl_SetVar2(interp, "sqlite_options", "secure_delete", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "secure_delete", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#ifdef YYTRACKMAXSTACKDEPTH
+  Tcl_SetVar2(interp, "sqlite_options", "yytrackmaxstackdepth", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "yytrackmaxstackdepth", "0", TCL_GLOBAL_ONLY);
+#endif
+
+#define LINKVAR(x) { \
+    static const int cv_ ## x = SQLITE_ ## x; \
+    Tcl_LinkVar(interp, "SQLITE_" #x, (char *)&(cv_ ## x), \
+                TCL_LINK_INT | TCL_LINK_READ_ONLY); }
+
+  LINKVAR( MAX_LENGTH );
+  LINKVAR( MAX_COLUMN );
+  LINKVAR( MAX_SQL_LENGTH );
+  LINKVAR( MAX_EXPR_DEPTH );
+  LINKVAR( MAX_COMPOUND_SELECT );
+  LINKVAR( MAX_VDBE_OP );
+  LINKVAR( MAX_FUNCTION_ARG );
+  LINKVAR( MAX_VARIABLE_NUMBER );
+  LINKVAR( MAX_PAGE_SIZE );
+  LINKVAR( MAX_PAGE_COUNT );
+  LINKVAR( MAX_LIKE_PATTERN_LENGTH );
+  LINKVAR( DEFAULT_TEMP_CACHE_SIZE );
+  LINKVAR( DEFAULT_CACHE_SIZE );
+  LINKVAR( DEFAULT_PAGE_SIZE );
+  LINKVAR( DEFAULT_FILE_FORMAT );
+  LINKVAR( MAX_ATTACHED );
+
+  {
+    static const int cv_TEMP_STORE = SQLITE_TEMP_STORE;
+    Tcl_LinkVar(interp, "TEMP_STORE", (char *)&(cv_TEMP_STORE),
+                TCL_LINK_INT | TCL_LINK_READ_ONLY);
+  }
+}
+
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqliteconfig_Init(Tcl_Interp *interp){
+  set_options(interp);
+  return TCL_OK;
+}
diff --git a/third_party/sqlite/src/test_devsym.c b/third_party/sqlite/src/test_devsym.c
new file mode 100755
index 0000000..0314804
--- /dev/null
+++ b/third_party/sqlite/src/test_devsym.c
@@ -0,0 +1,353 @@
+/*
+** 2008 Jan 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code that modified the OS layer in order to simulate
+** different device types (by overriding the return values of the 
+** xDeviceCharacteristics() and xSectorSize() methods).
+**
+** $Id: test_devsym.c,v 1.7 2008/06/06 11:11:26 danielk1977 Exp $
+*/
+#if SQLITE_TEST          /* This file is used for testing only */
+
+#include "sqlite3.h"
+#include "sqliteInt.h"
+
+/*
+** Maximum pathname length supported by the devsym backend.
+*/
+#define DEVSYM_MAX_PATHNAME 512
+
+/*
+** Name used to identify this VFS.
+*/
+#define DEVSYM_VFS_NAME "devsym"
+
+typedef struct devsym_file devsym_file;
+struct devsym_file {
+  sqlite3_file base;
+  sqlite3_file *pReal;
+};
+
+/*
+** Method declarations for devsym_file.
+*/
+static int devsymClose(sqlite3_file*);
+static int devsymRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
+static int devsymWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
+static int devsymTruncate(sqlite3_file*, sqlite3_int64 size);
+static int devsymSync(sqlite3_file*, int flags);
+static int devsymFileSize(sqlite3_file*, sqlite3_int64 *pSize);
+static int devsymLock(sqlite3_file*, int);
+static int devsymUnlock(sqlite3_file*, int);
+static int devsymCheckReservedLock(sqlite3_file*, int *);
+static int devsymFileControl(sqlite3_file*, int op, void *pArg);
+static int devsymSectorSize(sqlite3_file*);
+static int devsymDeviceCharacteristics(sqlite3_file*);
+
+/*
+** Method declarations for devsym_vfs.
+*/
+static int devsymOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
+static int devsymDelete(sqlite3_vfs*, const char *zName, int syncDir);
+static int devsymAccess(sqlite3_vfs*, const char *zName, int flags, int *);
+static int devsymFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+static void *devsymDlOpen(sqlite3_vfs*, const char *zFilename);
+static void devsymDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
+static void *devsymDlSym(sqlite3_vfs*,void*, const char *zSymbol);
+static void devsymDlClose(sqlite3_vfs*, void*);
+#endif /* SQLITE_OMIT_LOAD_EXTENSION */
+static int devsymRandomness(sqlite3_vfs*, int nByte, char *zOut);
+static int devsymSleep(sqlite3_vfs*, int microseconds);
+static int devsymCurrentTime(sqlite3_vfs*, double*);
+
+static sqlite3_vfs devsym_vfs = {
+  1,                     /* iVersion */
+  sizeof(devsym_file),      /* szOsFile */
+  DEVSYM_MAX_PATHNAME,      /* mxPathname */
+  0,                     /* pNext */
+  DEVSYM_VFS_NAME,          /* zName */
+  0,                     /* pAppData */
+  devsymOpen,               /* xOpen */
+  devsymDelete,             /* xDelete */
+  devsymAccess,             /* xAccess */
+  devsymFullPathname,       /* xFullPathname */
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+  devsymDlOpen,             /* xDlOpen */
+  devsymDlError,            /* xDlError */
+  devsymDlSym,              /* xDlSym */
+  devsymDlClose,            /* xDlClose */
+#else
+  0,                        /* xDlOpen */
+  0,                        /* xDlError */
+  0,                        /* xDlSym */
+  0,                        /* xDlClose */
+#endif /* SQLITE_OMIT_LOAD_EXTENSION */
+  devsymRandomness,         /* xRandomness */
+  devsymSleep,              /* xSleep */
+  devsymCurrentTime         /* xCurrentTime */
+};
+
+static sqlite3_io_methods devsym_io_methods = {
+  1,                            /* iVersion */
+  devsymClose,                      /* xClose */
+  devsymRead,                       /* xRead */
+  devsymWrite,                      /* xWrite */
+  devsymTruncate,                   /* xTruncate */
+  devsymSync,                       /* xSync */
+  devsymFileSize,                   /* xFileSize */
+  devsymLock,                       /* xLock */
+  devsymUnlock,                     /* xUnlock */
+  devsymCheckReservedLock,          /* xCheckReservedLock */
+  devsymFileControl,                /* xFileControl */
+  devsymSectorSize,                 /* xSectorSize */
+  devsymDeviceCharacteristics       /* xDeviceCharacteristics */
+};
+
+struct DevsymGlobal {
+  sqlite3_vfs *pVfs;
+  int iDeviceChar;
+  int iSectorSize;
+};
+struct DevsymGlobal g = {0, 0, 512};
+
+/*
+** Close an devsym-file.
+*/
+static int devsymClose(sqlite3_file *pFile){
+  devsym_file *p = (devsym_file *)pFile;
+  return sqlite3OsClose(p->pReal);
+}
+
+/*
+** Read data from an devsym-file.
+*/
+static int devsymRead(
+  sqlite3_file *pFile, 
+  void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  devsym_file *p = (devsym_file *)pFile;
+  return sqlite3OsRead(p->pReal, zBuf, iAmt, iOfst);
+}
+
+/*
+** Write data to an devsym-file.
+*/
+static int devsymWrite(
+  sqlite3_file *pFile, 
+  const void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  devsym_file *p = (devsym_file *)pFile;
+  return sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
+}
+
+/*
+** Truncate an devsym-file.
+*/
+static int devsymTruncate(sqlite3_file *pFile, sqlite_int64 size){
+  devsym_file *p = (devsym_file *)pFile;
+  return sqlite3OsTruncate(p->pReal, size);
+}
+
+/*
+** Sync an devsym-file.
+*/
+static int devsymSync(sqlite3_file *pFile, int flags){
+  devsym_file *p = (devsym_file *)pFile;
+  return sqlite3OsSync(p->pReal, flags);
+}
+
+/*
+** Return the current file-size of an devsym-file.
+*/
+static int devsymFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
+  devsym_file *p = (devsym_file *)pFile;
+  return sqlite3OsFileSize(p->pReal, pSize);
+}
+
+/*
+** Lock an devsym-file.
+*/
+static int devsymLock(sqlite3_file *pFile, int eLock){
+  devsym_file *p = (devsym_file *)pFile;
+  return sqlite3OsLock(p->pReal, eLock);
+}
+
+/*
+** Unlock an devsym-file.
+*/
+static int devsymUnlock(sqlite3_file *pFile, int eLock){
+  devsym_file *p = (devsym_file *)pFile;
+  return sqlite3OsUnlock(p->pReal, eLock);
+}
+
+/*
+** Check if another file-handle holds a RESERVED lock on an devsym-file.
+*/
+static int devsymCheckReservedLock(sqlite3_file *pFile, int *pResOut){
+  devsym_file *p = (devsym_file *)pFile;
+  return sqlite3OsCheckReservedLock(p->pReal, pResOut);
+}
+
+/*
+** File control method. For custom operations on an devsym-file.
+*/
+static int devsymFileControl(sqlite3_file *pFile, int op, void *pArg){
+  devsym_file *p = (devsym_file *)pFile;
+  return sqlite3OsFileControl(p->pReal, op, pArg);
+}
+
+/*
+** Return the sector-size in bytes for an devsym-file.
+*/
+static int devsymSectorSize(sqlite3_file *pFile){
+  return g.iSectorSize;
+}
+
+/*
+** Return the device characteristic flags supported by an devsym-file.
+*/
+static int devsymDeviceCharacteristics(sqlite3_file *pFile){
+  return g.iDeviceChar;
+}
+
+/*
+** Open an devsym file handle.
+*/
+static int devsymOpen(
+  sqlite3_vfs *pVfs,
+  const char *zName,
+  sqlite3_file *pFile,
+  int flags,
+  int *pOutFlags
+){
+  devsym_file *p = (devsym_file *)pFile;
+  pFile->pMethods = &devsym_io_methods;
+  p->pReal = (sqlite3_file *)&p[1];
+  return sqlite3OsOpen(g.pVfs, zName, p->pReal, flags, pOutFlags);
+}
+
+/*
+** Delete the file located at zPath. If the dirSync argument is true,
+** ensure the file-system modifications are synced to disk before
+** returning.
+*/
+static int devsymDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+  return sqlite3OsDelete(g.pVfs, zPath, dirSync);
+}
+
+/*
+** Test for access permissions. Return true if the requested permission
+** is available, or false otherwise.
+*/
+static int devsymAccess(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int flags, 
+  int *pResOut
+){
+  return sqlite3OsAccess(g.pVfs, zPath, flags, pResOut);
+}
+
+/*
+** Populate buffer zOut with the full canonical pathname corresponding
+** to the pathname in zPath. zOut is guaranteed to point to a buffer
+** of at least (DEVSYM_MAX_PATHNAME+1) bytes.
+*/
+static int devsymFullPathname(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int nOut, 
+  char *zOut
+){
+  return sqlite3OsFullPathname(g.pVfs, zPath, nOut, zOut);
+}
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+/*
+** Open the dynamic library located at zPath and return a handle.
+*/
+static void *devsymDlOpen(sqlite3_vfs *pVfs, const char *zPath){
+  return sqlite3OsDlOpen(g.pVfs, zPath);
+}
+
+/*
+** Populate the buffer zErrMsg (size nByte bytes) with a human readable
+** utf-8 string describing the most recent error encountered associated 
+** with dynamic libraries.
+*/
+static void devsymDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
+  sqlite3OsDlError(g.pVfs, nByte, zErrMsg);
+}
+
+/*
+** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
+*/
+static void *devsymDlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol){
+  return sqlite3OsDlSym(g.pVfs, pHandle, zSymbol);
+}
+
+/*
+** Close the dynamic library handle pHandle.
+*/
+static void devsymDlClose(sqlite3_vfs *pVfs, void *pHandle){
+  sqlite3OsDlClose(g.pVfs, pHandle);
+}
+#endif /* SQLITE_OMIT_LOAD_EXTENSION */
+
+/*
+** Populate the buffer pointed to by zBufOut with nByte bytes of 
+** random data.
+*/
+static int devsymRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
+  return sqlite3OsRandomness(g.pVfs, nByte, zBufOut);
+}
+
+/*
+** Sleep for nMicro microseconds. Return the number of microseconds 
+** actually slept.
+*/
+static int devsymSleep(sqlite3_vfs *pVfs, int nMicro){
+  return sqlite3OsSleep(g.pVfs, nMicro);
+}
+
+/*
+** Return the current time as a Julian Day number in *pTimeOut.
+*/
+static int devsymCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
+  return sqlite3OsCurrentTime(g.pVfs, pTimeOut);
+}
+
+/*
+** This procedure registers the devsym vfs with SQLite. If the argument is
+** true, the devsym vfs becomes the new default vfs. It is the only publicly
+** available function in this file.
+*/
+void devsym_register(int iDeviceChar, int iSectorSize){
+  if( g.pVfs==0 ){
+    g.pVfs = sqlite3_vfs_find(0);
+    devsym_vfs.szOsFile += g.pVfs->szOsFile;
+    sqlite3_vfs_register(&devsym_vfs, 0);
+  }
+  if( iDeviceChar>=0 ){
+    g.iDeviceChar = iDeviceChar;
+  }
+  if( iSectorSize>=0 ){
+    g.iSectorSize = iSectorSize;
+  }
+}
+
+#endif
diff --git a/third_party/sqlite/src/test_func.c b/third_party/sqlite/src/test_func.c
new file mode 100755
index 0000000..eaafc23
--- /dev/null
+++ b/third_party/sqlite/src/test_func.c
@@ -0,0 +1,431 @@
+/*
+** 2008 March 19
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing all sorts of SQLite interfaces.  This code
+** implements new SQL functions used by the test scripts.
+**
+** $Id: test_func.c,v 1.10 2008/08/02 03:50:39 drh Exp $
+*/
+#include "sqlite3.h"
+#include "tcl.h"
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+
+/*
+** Allocate nByte bytes of space using sqlite3_malloc(). If the
+** allocation fails, call sqlite3_result_error_nomem() to notify
+** the database handle that malloc() has failed.
+*/
+static void *testContextMalloc(sqlite3_context *context, int nByte){
+  char *z = sqlite3_malloc(nByte);
+  if( !z && nByte>0 ){
+    sqlite3_result_error_nomem(context);
+  }
+  return z;
+}
+
+/*
+** This function generates a string of random characters.  Used for
+** generating test data.
+*/
+static void randStr(sqlite3_context *context, int argc, sqlite3_value **argv){
+  static const unsigned char zSrc[] = 
+     "abcdefghijklmnopqrstuvwxyz"
+     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+     "0123456789"
+     ".-!,:*^+=_|?/<> ";
+  int iMin, iMax, n, r, i;
+  unsigned char zBuf[1000];
+
+  /* It used to be possible to call randstr() with any number of arguments,
+  ** but now it is registered with SQLite as requiring exactly 2.
+  */
+  assert(argc==2);
+
+  iMin = sqlite3_value_int(argv[0]);
+  if( iMin<0 ) iMin = 0;
+  if( iMin>=sizeof(zBuf) ) iMin = sizeof(zBuf)-1;
+  iMax = sqlite3_value_int(argv[1]);
+  if( iMax<iMin ) iMax = iMin;
+  if( iMax>=sizeof(zBuf) ) iMax = sizeof(zBuf)-1;
+  n = iMin;
+  if( iMax>iMin ){
+    sqlite3_randomness(sizeof(r), &r);
+    r &= 0x7fffffff;
+    n += r%(iMax + 1 - iMin);
+  }
+  assert( n<sizeof(zBuf) );
+  sqlite3_randomness(n, zBuf);
+  for(i=0; i<n; i++){
+    zBuf[i] = zSrc[zBuf[i]%(sizeof(zSrc)-1)];
+  }
+  zBuf[n] = 0;
+  sqlite3_result_text(context, (char*)zBuf, n, SQLITE_TRANSIENT);
+}
+
+/*
+** The following two SQL functions are used to test returning a text
+** result with a destructor. Function 'test_destructor' takes one argument
+** and returns the same argument interpreted as TEXT. A destructor is
+** passed with the sqlite3_result_text() call.
+**
+** SQL function 'test_destructor_count' returns the number of outstanding 
+** allocations made by 'test_destructor';
+**
+** WARNING: Not threadsafe.
+*/
+static int test_destructor_count_var = 0;
+static void destructor(void *p){
+  char *zVal = (char *)p;
+  assert(zVal);
+  zVal--;
+  sqlite3_free(zVal);
+  test_destructor_count_var--;
+}
+static void test_destructor(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  char *zVal;
+  int len;
+  
+  test_destructor_count_var++;
+  assert( nArg==1 );
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  len = sqlite3_value_bytes(argv[0]); 
+  zVal = testContextMalloc(pCtx, len+3);
+  if( !zVal ){
+    return;
+  }
+  zVal[len+1] = 0;
+  zVal[len+2] = 0;
+  zVal++;
+  memcpy(zVal, sqlite3_value_text(argv[0]), len);
+  sqlite3_result_text(pCtx, zVal, -1, destructor);
+}
+#ifndef SQLITE_OMIT_UTF16
+static void test_destructor16(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  char *zVal;
+  int len;
+  
+  test_destructor_count_var++;
+  assert( nArg==1 );
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  len = sqlite3_value_bytes16(argv[0]); 
+  zVal = testContextMalloc(pCtx, len+3);
+  if( !zVal ){
+    return;
+  }
+  zVal[len+1] = 0;
+  zVal[len+2] = 0;
+  zVal++;
+  memcpy(zVal, sqlite3_value_text16(argv[0]), len);
+  sqlite3_result_text16(pCtx, zVal, -1, destructor);
+}
+#endif
+static void test_destructor_count(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  sqlite3_result_int(pCtx, test_destructor_count_var);
+}
+
+/*
+** Routines for testing the sqlite3_get_auxdata() and sqlite3_set_auxdata()
+** interface.
+**
+** The test_auxdata() SQL function attempts to register each of its arguments
+** as auxiliary data.  If there are no prior registrations of aux data for
+** that argument (meaning the argument is not a constant or this is its first
+** call) then the result for that argument is 0.  If there is a prior
+** registration, the result for that argument is 1.  The overall result
+** is the individual argument results separated by spaces.
+*/
+static void free_test_auxdata(void *p) {sqlite3_free(p);}
+static void test_auxdata(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  int i;
+  char *zRet = testContextMalloc(pCtx, nArg*2);
+  if( !zRet ) return;
+  memset(zRet, 0, nArg*2);
+  for(i=0; i<nArg; i++){
+    char const *z = (char*)sqlite3_value_text(argv[i]);
+    if( z ){
+      int n;
+      char *zAux = sqlite3_get_auxdata(pCtx, i);
+      if( zAux ){
+        zRet[i*2] = '1';
+        assert( strcmp(zAux,z)==0 );
+      }else {
+        zRet[i*2] = '0';
+      }
+      n = strlen(z) + 1;
+      zAux = testContextMalloc(pCtx, n);
+      if( zAux ){
+        memcpy(zAux, z, n);
+        sqlite3_set_auxdata(pCtx, i, zAux, free_test_auxdata);
+      }
+      zRet[i*2+1] = ' ';
+    }
+  }
+  sqlite3_result_text(pCtx, zRet, 2*nArg-1, free_test_auxdata);
+}
+
+/*
+** A function to test error reporting from user functions. This function
+** returns a copy of its first argument as the error message.  If the
+** second argument exists, it becomes the error code.
+*/
+static void test_error(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  sqlite3_result_error(pCtx, (char*)sqlite3_value_text(argv[0]), -1);
+  if( nArg==2 ){
+    sqlite3_result_error_code(pCtx, sqlite3_value_int(argv[1]));
+  }
+}
+
+/*
+** This function takes two arguments.  It performance UTF-8/16 type
+** conversions on the first argument then returns a copy of the second
+** argument.
+**
+** This function is used in cases such as the following:
+**
+**      SELECT test_isolation(x,x) FROM t1;
+**
+** We want to verify that the type conversions that occur on the
+** first argument do not invalidate the second argument.
+*/
+static void test_isolation(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+#ifndef SQLITE_OMIT_UTF16
+  sqlite3_value_text16(argv[0]);
+  sqlite3_value_text(argv[0]);
+  sqlite3_value_text16(argv[0]);
+  sqlite3_value_text(argv[0]);
+#endif
+  sqlite3_result_value(pCtx, argv[1]);
+}
+
+/*
+** Invoke an SQL statement recursively.  The function result is the 
+** first column of the first row of the result set.
+*/
+static void test_eval(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  sqlite3_stmt *pStmt;
+  int rc;
+  sqlite3 *db = sqlite3_context_db_handle(pCtx);
+  const char *zSql;
+
+  zSql = (char*)sqlite3_value_text(argv[0]);
+  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_step(pStmt);
+    if( rc==SQLITE_ROW ){
+      sqlite3_result_value(pCtx, sqlite3_column_value(pStmt, 0));
+    }
+    rc = sqlite3_finalize(pStmt);
+  }
+  if( rc ){
+    char *zErr;
+    assert( pStmt==0 );
+    zErr = sqlite3_mprintf("sqlite3_prepare_v2() error: %s",sqlite3_errmsg(db));
+    sqlite3_result_text(pCtx, zErr, -1, sqlite3_free);
+    sqlite3_result_error_code(pCtx, rc);
+  }
+}
+
+
+static int registerTestFunctions(sqlite3 *db){
+  static const struct {
+     char *zName;
+     signed char nArg;
+     unsigned char eTextRep; /* 1: UTF-16.  0: UTF-8 */
+     void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
+  } aFuncs[] = {
+    { "randstr",               2, SQLITE_UTF8, randStr    },
+    { "test_destructor",       1, SQLITE_UTF8, test_destructor},
+#ifndef SQLITE_OMIT_UTF16
+    { "test_destructor16",     1, SQLITE_UTF8, test_destructor16},
+#endif
+    { "test_destructor_count", 0, SQLITE_UTF8, test_destructor_count},
+    { "test_auxdata",         -1, SQLITE_UTF8, test_auxdata},
+    { "test_error",            1, SQLITE_UTF8, test_error},
+    { "test_error",            2, SQLITE_UTF8, test_error},
+    { "test_eval",             1, SQLITE_UTF8, test_eval},
+    { "test_isolation",        2, SQLITE_UTF8, test_isolation},
+  };
+  int i;
+  extern int Md5_Register(sqlite3*);
+
+  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
+    sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg,
+        aFuncs[i].eTextRep, 0, aFuncs[i].xFunc, 0, 0);
+  }
+  Md5_Register(db);
+  return SQLITE_OK;
+}
+
+/*
+** TCLCMD:  autoinstall_test_functions
+**
+** Invoke this TCL command to use sqlite3_auto_extension() to cause
+** the standard set of test functions to be loaded into each new
+** database connection.
+*/
+static int autoinstall_test_funcs(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc = sqlite3_auto_extension((void*)registerTestFunctions);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return TCL_OK;
+}
+
+/*
+** A bogus step function and finalizer function.
+*/
+static void tStep(sqlite3_context *a, int b, sqlite3_value **c){}
+static void tFinal(sqlite3_context *a){}
+
+
+/*
+** tclcmd:  abuse_create_function
+**
+** Make various calls to sqlite3_create_function that do not have valid
+** parameters.  Verify that the error condition is detected and reported.
+*/
+static int abuse_create_function(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  extern int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
+  sqlite3 *db;
+  int rc;
+  int mxArg;
+
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+
+  rc = sqlite3_create_function(db, "tx", 1, SQLITE_UTF8, 0, tStep,tStep,tFinal);
+  if( rc!=SQLITE_ERROR ) goto abuse_err;
+  if( sqlite3_errcode(db)!=SQLITE_ERROR ) goto abuse_err;
+  if( strcmp(sqlite3_errmsg(db), "bad parameters")!=0 ) goto abuse_err;
+
+  rc = sqlite3_create_function(db, "tx", 1, SQLITE_UTF8, 0, tStep, tStep, 0);
+  if( rc!=SQLITE_ERROR ) goto abuse_err;
+  if( sqlite3_errcode(db)!=SQLITE_ERROR ) goto abuse_err;
+  if( strcmp(sqlite3_errmsg(db), "bad parameters")!=0 ) goto abuse_err;
+
+  rc = sqlite3_create_function(db, "tx", 1, SQLITE_UTF8, 0, tStep, 0, tFinal);
+  if( rc!=SQLITE_ERROR ) goto abuse_err;
+  if( sqlite3_errcode(db)!=SQLITE_ERROR ) goto abuse_err;
+  if( strcmp(sqlite3_errmsg(db), "bad parameters")!=0 ) goto abuse_err;
+
+  rc = sqlite3_create_function(db, "tx", 1, SQLITE_UTF8, 0, 0, 0, tFinal);
+  if( rc!=SQLITE_ERROR ) goto abuse_err;
+  if( sqlite3_errcode(db)!=SQLITE_ERROR ) goto abuse_err;
+  if( strcmp(sqlite3_errmsg(db), "bad parameters")!=0 ) goto abuse_err;
+
+  rc = sqlite3_create_function(db, "tx", 1, SQLITE_UTF8, 0, 0, tStep, 0);
+  if( rc!=SQLITE_ERROR ) goto abuse_err;
+  if( sqlite3_errcode(db)!=SQLITE_ERROR ) goto abuse_err;
+  if( strcmp(sqlite3_errmsg(db), "bad parameters")!=0 ) goto abuse_err;
+
+  rc = sqlite3_create_function(db, "tx", -2, SQLITE_UTF8, 0, tStep, 0, 0);
+  if( rc!=SQLITE_ERROR ) goto abuse_err;
+  if( sqlite3_errcode(db)!=SQLITE_ERROR ) goto abuse_err;
+  if( strcmp(sqlite3_errmsg(db), "bad parameters")!=0 ) goto abuse_err;
+
+  rc = sqlite3_create_function(db, "tx", 128, SQLITE_UTF8, 0, tStep, 0, 0);
+  if( rc!=SQLITE_ERROR ) goto abuse_err;
+  if( sqlite3_errcode(db)!=SQLITE_ERROR ) goto abuse_err;
+  if( strcmp(sqlite3_errmsg(db), "bad parameters")!=0 ) goto abuse_err;
+
+  rc = sqlite3_create_function(db, "funcxx"
+       "_123456789_123456789_123456789_123456789_123456789"
+       "_123456789_123456789_123456789_123456789_123456789"
+       "_123456789_123456789_123456789_123456789_123456789"
+       "_123456789_123456789_123456789_123456789_123456789"
+       "_123456789_123456789_123456789_123456789_123456789",
+       1, SQLITE_UTF8, 0, tStep, 0, 0);
+  if( rc!=SQLITE_ERROR ) goto abuse_err;
+  if( sqlite3_errcode(db)!=SQLITE_ERROR ) goto abuse_err;
+  if( strcmp(sqlite3_errmsg(db), "bad parameters")!=0 ) goto abuse_err;
+
+  /* This last function registration should actually work.  Generate
+  ** a no-op function (that always returns NULL) and which has the
+  ** maximum-length function name and the maximum number of parameters.
+  */
+  sqlite3_limit(db, SQLITE_LIMIT_FUNCTION_ARG, 10000);
+  mxArg = sqlite3_limit(db, SQLITE_LIMIT_FUNCTION_ARG, -1);
+  rc = sqlite3_create_function(db, "nullx"
+       "_123456789_123456789_123456789_123456789_123456789"
+       "_123456789_123456789_123456789_123456789_123456789"
+       "_123456789_123456789_123456789_123456789_123456789"
+       "_123456789_123456789_123456789_123456789_123456789"
+       "_123456789_123456789_123456789_123456789_123456789",
+       mxArg, SQLITE_UTF8, 0, tStep, 0, 0);
+  if( rc!=SQLITE_OK ) goto abuse_err;
+                                
+  return TCL_OK;
+
+abuse_err:
+  Tcl_AppendResult(interp, "sqlite3_create_function abused test failed", 
+                   (char*)0);
+  return TCL_ERROR;
+}
+
+
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest_func_Init(Tcl_Interp *interp){
+  static struct {
+     char *zName;
+     Tcl_ObjCmdProc *xProc;
+  } aObjCmd[] = {
+     { "autoinstall_test_functions",    autoinstall_test_funcs },
+     { "abuse_create_function",         abuse_create_function  },
+  };
+  int i;
+  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
+    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, aObjCmd[i].xProc, 0, 0);
+  }
+  sqlite3_initialize();
+  sqlite3_auto_extension((void*)registerTestFunctions);
+  return TCL_OK;
+}
diff --git a/third_party/sqlite/src/test_hexio.c b/third_party/sqlite/src/test_hexio.c
new file mode 100755
index 0000000..9e1e8de
--- /dev/null
+++ b/third_party/sqlite/src/test_hexio.c
@@ -0,0 +1,342 @@
+/*
+** 2007 April 6
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing all sorts of SQLite interfaces.  This code
+** implements TCL commands for reading and writing the binary
+** database files and displaying the content of those files as
+** hexadecimal.  We could, in theory, use the built-in "binary"
+** command of TCL to do a lot of this, but there are some issues
+** with historical versions of the "binary" command.  So it seems
+** easier and safer to build our own mechanism.
+**
+** $Id: test_hexio.c,v 1.7 2008/05/12 16:17:42 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "tcl.h"
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+
+/*
+** Convert binary to hex.  The input zBuf[] contains N bytes of
+** binary data.  zBuf[] is 2*n+1 bytes long.  Overwrite zBuf[]
+** with a hexadecimal representation of its original binary input.
+*/
+void sqlite3TestBinToHex(unsigned char *zBuf, int N){
+  const unsigned char zHex[] = "0123456789ABCDEF";
+  int i, j;
+  unsigned char c;
+  i = N*2;
+  zBuf[i--] = 0;
+  for(j=N-1; j>=0; j--){
+    c = zBuf[j];
+    zBuf[i--] = zHex[c&0xf];
+    zBuf[i--] = zHex[c>>4];
+  }
+  assert( i==-1 );
+}
+
+/*
+** Convert hex to binary.  The input zIn[] contains N bytes of
+** hexadecimal.  Convert this into binary and write aOut[] with
+** the binary data.  Spaces in the original input are ignored.
+** Return the number of bytes of binary rendered.
+*/
+int sqlite3TestHexToBin(const unsigned char *zIn, int N, unsigned char *aOut){
+  const unsigned char aMap[] = {
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     1, 2, 3, 4, 5, 6, 7, 8,  9,10, 0, 0, 0, 0, 0, 0,
+     0,11,12,13,14,15,16, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0,11,12,13,14,15,16, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+  };
+  int i, j;
+  int hi=1;
+  unsigned char c;
+
+  for(i=j=0; i<N; i++){
+    c = aMap[zIn[i]];
+    if( c==0 ) continue;
+    if( hi ){
+      aOut[j] = (c-1)<<4;
+      hi = 0;
+    }else{
+      aOut[j++] |= c-1;
+      hi = 1;
+    }
+  }
+  return j;
+}
+
+
+/*
+** Usage:   hexio_read  FILENAME  OFFSET  AMT
+**
+** Read AMT bytes from file FILENAME beginning at OFFSET from the
+** beginning of the file.  Convert that information to hexadecimal
+** and return the resulting HEX string.
+*/
+static int hexio_read(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int offset;
+  int amt, got;
+  const char *zFile;
+  unsigned char *zBuf;
+  FILE *in;
+
+  if( objc!=4 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "FILENAME OFFSET AMT");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[2], &offset) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[3], &amt) ) return TCL_ERROR;
+  zFile = Tcl_GetString(objv[1]);
+  zBuf = sqlite3_malloc( amt*2+1 );
+  if( zBuf==0 ){
+    return TCL_ERROR;
+  }
+  in = fopen(zFile, "rb");
+  if( in==0 ){
+    in = fopen(zFile, "r");
+  }
+  if( in==0 ){
+    Tcl_AppendResult(interp, "cannot open input file ", zFile, 0);
+    return TCL_ERROR;
+  }
+  fseek(in, offset, SEEK_SET);
+  got = fread(zBuf, 1, amt, in);
+  fclose(in);
+  if( got<0 ){
+    got = 0;
+  }
+  sqlite3TestBinToHex(zBuf, got);
+  Tcl_AppendResult(interp, zBuf, 0);
+  sqlite3_free(zBuf);
+  return TCL_OK;
+}
+
+
+/*
+** Usage:   hexio_write  FILENAME  OFFSET  DATA
+**
+** Write DATA into file FILENAME beginning at OFFSET from the
+** beginning of the file.  DATA is expressed in hexadecimal.
+*/
+static int hexio_write(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int offset;
+  int nIn, nOut, written;
+  const char *zFile;
+  const unsigned char *zIn;
+  unsigned char *aOut;
+  FILE *out;
+
+  if( objc!=4 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "FILENAME OFFSET HEXDATA");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[2], &offset) ) return TCL_ERROR;
+  zFile = Tcl_GetString(objv[1]);
+  zIn = (const unsigned char *)Tcl_GetStringFromObj(objv[3], &nIn);
+  aOut = sqlite3_malloc( nIn/2 );
+  if( aOut==0 ){
+    return TCL_ERROR;
+  }
+  nOut = sqlite3TestHexToBin(zIn, nIn, aOut);
+  out = fopen(zFile, "r+b");
+  if( out==0 ){
+    out = fopen(zFile, "r+");
+  }
+  if( out==0 ){
+    Tcl_AppendResult(interp, "cannot open output file ", zFile, 0);
+    return TCL_ERROR;
+  }
+  fseek(out, offset, SEEK_SET);
+  written = fwrite(aOut, 1, nOut, out);
+  sqlite3_free(aOut);
+  fclose(out);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(written));
+  return TCL_OK;
+}
+
+/*
+** USAGE:   hexio_get_int   HEXDATA
+**
+** Interpret the HEXDATA argument as a big-endian integer.  Return
+** the value of that integer.  HEXDATA can contain between 2 and 8
+** hexadecimal digits.
+*/
+static int hexio_get_int(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int val;
+  int nIn, nOut;
+  const unsigned char *zIn;
+  unsigned char *aOut;
+  unsigned char aNum[4];
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "HEXDATA");
+    return TCL_ERROR;
+  }
+  zIn = (const unsigned char *)Tcl_GetStringFromObj(objv[1], &nIn);
+  aOut = sqlite3_malloc( nIn/2 );
+  if( aOut==0 ){
+    return TCL_ERROR;
+  }
+  nOut = sqlite3TestHexToBin(zIn, nIn, aOut);
+  if( nOut>=4 ){
+    memcpy(aNum, aOut, 4);
+  }else{
+    memset(aNum, 0, sizeof(aNum));
+    memcpy(&aNum[4-nOut], aOut, nOut);
+  }
+  sqlite3_free(aOut);
+  val = (aNum[0]<<24) | (aNum[1]<<16) | (aNum[2]<<8) | aNum[3];
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(val));
+  return TCL_OK;
+}
+
+
+/*
+** USAGE:   hexio_render_int16   INTEGER
+**
+** Render INTEGER has a 16-bit big-endian integer in hexadecimal.
+*/
+static int hexio_render_int16(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int val;
+  unsigned char aNum[10];
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "INTEGER");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[1], &val) ) return TCL_ERROR;
+  aNum[0] = val>>8;
+  aNum[1] = val;
+  sqlite3TestBinToHex(aNum, 2);
+  Tcl_SetObjResult(interp, Tcl_NewStringObj((char*)aNum, 4));
+  return TCL_OK;
+}
+
+
+/*
+** USAGE:   hexio_render_int32   INTEGER
+**
+** Render INTEGER has a 32-bit big-endian integer in hexadecimal.
+*/
+static int hexio_render_int32(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int val;
+  unsigned char aNum[10];
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "INTEGER");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[1], &val) ) return TCL_ERROR;
+  aNum[0] = val>>24;
+  aNum[1] = val>>16;
+  aNum[2] = val>>8;
+  aNum[3] = val;
+  sqlite3TestBinToHex(aNum, 4);
+  Tcl_SetObjResult(interp, Tcl_NewStringObj((char*)aNum, 8));
+  return TCL_OK;
+}
+
+/*
+** USAGE:  utf8_to_utf8  HEX
+**
+** The argument is a UTF8 string represented in hexadecimal.
+** The UTF8 might not be well-formed.  Run this string through
+** sqlite3Utf8to8() convert it back to hex and return the result.
+*/
+static int utf8_to_utf8(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifdef SQLITE_DEBUG
+  int n;
+  int nOut;
+  const unsigned char *zOrig;
+  unsigned char *z;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "HEX");
+    return TCL_ERROR;
+  }
+  zOrig = (unsigned char *)Tcl_GetStringFromObj(objv[1], &n);
+  z = sqlite3_malloc( n+3 );
+  n = sqlite3TestHexToBin(zOrig, n, z);
+  z[n] = 0;
+  nOut = sqlite3Utf8To8(z);
+  sqlite3TestBinToHex(z,nOut);
+  Tcl_AppendResult(interp, (char*)z, 0);
+  sqlite3_free(z);
+#endif
+  return TCL_OK;
+}
+
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest_hexio_Init(Tcl_Interp *interp){
+  static struct {
+     char *zName;
+     Tcl_ObjCmdProc *xProc;
+  } aObjCmd[] = {
+     { "hexio_read",                   hexio_read            },
+     { "hexio_write",                  hexio_write           },
+     { "hexio_get_int",                hexio_get_int         },
+     { "hexio_render_int16",           hexio_render_int16    },
+     { "hexio_render_int32",           hexio_render_int32    },
+     { "utf8_to_utf8",                 utf8_to_utf8          },
+  };
+  int i;
+  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
+    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, aObjCmd[i].xProc, 0, 0);
+  }
+  return TCL_OK;
+}
diff --git a/third_party/sqlite/src/test_loadext.c b/third_party/sqlite/src/test_loadext.c
new file mode 100755
index 0000000..e973566
--- /dev/null
+++ b/third_party/sqlite/src/test_loadext.c
@@ -0,0 +1,124 @@
+/*
+** 2006 June 14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Test extension for testing the sqlite3_load_extension() function.
+**
+** $Id: test_loadext.c,v 1.3 2008/08/02 03:50:39 drh Exp $
+*/
+#include <string.h>
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+
+/*
+** The half() SQL function returns half of its input value.
+*/
+static void halfFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  sqlite3_result_double(context, 0.5*sqlite3_value_double(argv[0]));
+}
+
+/*
+** SQL functions to call the sqlite3_status function and return results.
+*/
+static void statusFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int op, mx, cur, resetFlag, rc;
+  if( sqlite3_value_type(argv[0])==SQLITE_INTEGER ){
+    op = sqlite3_value_int(argv[0]);
+  }else if( sqlite3_value_type(argv[0])==SQLITE_TEXT ){
+    int i;
+    const char *zName;
+    static const struct {
+      const char *zName;
+      int op;
+    } aOp[] = {
+      { "MEMORY_USED",         SQLITE_STATUS_MEMORY_USED         },
+      { "PAGECACHE_USED",      SQLITE_STATUS_PAGECACHE_USED      },
+      { "PAGECACHE_OVERFLOW",  SQLITE_STATUS_PAGECACHE_OVERFLOW  },
+      { "SCRATCH_USED",        SQLITE_STATUS_SCRATCH_USED        },
+      { "SCRATCH_OVERFLOW",    SQLITE_STATUS_SCRATCH_OVERFLOW    },
+      { "MALLOC_SIZE",         SQLITE_STATUS_MALLOC_SIZE         },
+    };
+    int nOp = sizeof(aOp)/sizeof(aOp[0]);
+    zName = (const char*)sqlite3_value_text(argv[0]);
+    for(i=0; i<nOp; i++){
+      if( strcmp(aOp[i].zName, zName)==0 ){
+        op = aOp[i].op;
+        break;
+      }
+    }
+    if( i>=nOp ){
+      char *zMsg = sqlite3_mprintf("unknown status property: %s", zName);
+      sqlite3_result_error(context, zMsg, -1);
+      sqlite3_free(zMsg);
+      return;
+    }
+  }else{
+    sqlite3_result_error(context, "unknown status type", -1);
+    return;
+  }
+  if( argc==2 ){
+    resetFlag = sqlite3_value_int(argv[1]);
+  }else{
+    resetFlag = 0;
+  }
+  rc = sqlite3_status(op, &cur, &mx, resetFlag);
+  if( rc!=SQLITE_OK ){
+    char *zMsg = sqlite3_mprintf("sqlite3_status(%d,...) returns %d", op, rc);
+    sqlite3_result_error(context, zMsg, -1);
+    sqlite3_free(zMsg);
+    return;
+  } 
+  if( argc==2 ){
+    sqlite3_result_int(context, mx);
+  }else{
+    sqlite3_result_int(context, cur);
+  }
+}
+
+/*
+** Extension load function.
+*/
+int testloadext_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int nErr = 0;
+  SQLITE_EXTENSION_INIT2(pApi);
+  nErr |= sqlite3_create_function(db, "half", 1, SQLITE_ANY, 0, halfFunc, 0, 0);
+  nErr |= sqlite3_create_function(db, "sqlite3_status", 1, SQLITE_ANY, 0,
+                          statusFunc, 0, 0);
+  nErr |= sqlite3_create_function(db, "sqlite3_status", 2, SQLITE_ANY, 0,
+                          statusFunc, 0, 0);
+  return nErr ? SQLITE_ERROR : SQLITE_OK;
+}
+
+/*
+** Another extension entry point. This one always fails.
+*/
+int testbrokenext_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  char *zErr;
+  SQLITE_EXTENSION_INIT2(pApi);
+  zErr = sqlite3_mprintf("broken!");
+  *pzErrMsg = zErr;
+  return 1;
+}
diff --git a/third_party/sqlite/src/test_malloc.c b/third_party/sqlite/src/test_malloc.c
new file mode 100755
index 0000000..24d2389
--- /dev/null
+++ b/third_party/sqlite/src/test_malloc.c
@@ -0,0 +1,1339 @@
+/*
+** 2007 August 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains code used to implement test interfaces to the
+** memory allocation subsystem.
+**
+** $Id: test_malloc.c,v 1.47 2008/08/05 17:53:24 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "tcl.h"
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+/*
+** This structure is used to encapsulate the global state variables used 
+** by malloc() fault simulation.
+*/
+static struct MemFault {
+  int iCountdown;         /* Number of pending successes before a failure */
+  int nRepeat;            /* Number of times to repeat the failure */
+  int nBenign;            /* Number of benign failures seen since last config */
+  int nFail;              /* Number of failures seen since last config */
+  u8 enable;              /* True if enabled */
+  int isInstalled;        /* True if the fault simulation layer is installed */
+  int isBenignMode;       /* True if malloc failures are considered benign */
+  sqlite3_mem_methods m;  /* 'Real' malloc implementation */
+} memfault;
+
+/*
+** This routine exists as a place to set a breakpoint that will
+** fire on any simulated malloc() failure.
+*/
+static void sqlite3Fault(void){
+  static int cnt = 0;
+  cnt++;
+}
+
+/*
+** Check to see if a fault should be simulated.  Return true to simulate
+** the fault.  Return false if the fault should not be simulated.
+*/
+static int faultsimStep(){
+  if( likely(!memfault.enable) ){
+    return 0;
+  }
+  if( memfault.iCountdown>0 ){
+    memfault.iCountdown--;
+    return 0;
+  }
+  sqlite3Fault();
+  memfault.nFail++;
+  if( memfault.isBenignMode>0 ){
+    memfault.nBenign++;
+  }
+  memfault.nRepeat--;
+  if( memfault.nRepeat<=0 ){
+    memfault.enable = 0;
+  }
+  return 1;  
+}
+
+/*
+** A version of sqlite3_mem_methods.xMalloc() that includes fault simulation
+** logic.
+*/
+static void *faultsimMalloc(int n){
+  void *p = 0;
+  if( !faultsimStep() ){
+    p = memfault.m.xMalloc(n);
+  }
+  return p;
+}
+
+
+/*
+** A version of sqlite3_mem_methods.xRealloc() that includes fault simulation
+** logic.
+*/
+static void *faultsimRealloc(void *pOld, int n){
+  void *p = 0;
+  if( !faultsimStep() ){
+    p = memfault.m.xRealloc(pOld, n);
+  }
+  return p;
+}
+
+/* 
+** The following method calls are passed directly through to the underlying
+** malloc system:
+**
+**     xFree
+**     xSize
+**     xRoundup
+**     xInit
+**     xShutdown
+*/
+static void faultsimFree(void *p){
+  memfault.m.xFree(p);
+}
+static int faultsimSize(void *p){
+  return memfault.m.xSize(p);
+}
+static int faultsimRoundup(int n){
+  return memfault.m.xRoundup(n);
+}
+static int faultsimInit(void *p){
+  return memfault.m.xInit(memfault.m.pAppData);
+}
+static void faultsimShutdown(void *p){
+  memfault.m.xShutdown(memfault.m.pAppData);
+}
+
+/*
+** This routine configures the malloc failure simulation.  After
+** calling this routine, the next nDelay mallocs will succeed, followed
+** by a block of nRepeat failures, after which malloc() calls will begin
+** to succeed again.
+*/
+static void faultsimConfig(int nDelay, int nRepeat){
+  memfault.iCountdown = nDelay;
+  memfault.nRepeat = nRepeat;
+  memfault.nBenign = 0;
+  memfault.nFail = 0;
+  memfault.enable = nDelay>=0;
+}
+
+/*
+** Return the number of faults (both hard and benign faults) that have
+** occurred since the injector was last configured.
+*/
+static int faultsimFailures(void){
+  return memfault.nFail;
+}
+
+/*
+** Return the number of benign faults that have occurred since the
+** injector was last configured.
+*/
+static int faultsimBenignFailures(void){
+  return memfault.nBenign;
+}
+
+/*
+** Return the number of successes that will occur before the next failure.
+** If no failures are scheduled, return -1.
+*/
+static int faultsimPending(void){
+  if( memfault.enable ){
+    return memfault.iCountdown;
+  }else{
+    return -1;
+  }
+}
+
+
+static void faultsimBeginBenign(void){
+  memfault.isBenignMode++;
+}
+static void faultsimEndBenign(void){
+  memfault.isBenignMode--;
+}
+
+/*
+** Add or remove the fault-simulation layer using sqlite3_config(). If
+** the argument is non-zero, the 
+*/
+static int faultsimInstall(int install){
+  static struct sqlite3_mem_methods m = {
+    faultsimMalloc,                   /* xMalloc */
+    faultsimFree,                     /* xFree */
+    faultsimRealloc,                  /* xRealloc */
+    faultsimSize,                     /* xSize */
+    faultsimRoundup,                  /* xRoundup */
+    faultsimInit,                     /* xInit */
+    faultsimShutdown,                 /* xShutdown */
+    0                                 /* pAppData */
+  };
+  int rc;
+
+  install = (install ? 1 : 0);
+  assert(memfault.isInstalled==1 || memfault.isInstalled==0);
+
+  if( install==memfault.isInstalled ){
+    return SQLITE_ERROR;
+  }
+
+  if( install ){
+    rc = sqlite3_config(SQLITE_CONFIG_GETMALLOC, &memfault.m);
+    assert(memfault.m.xMalloc);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3_config(SQLITE_CONFIG_MALLOC, &m);
+    }
+    sqlite3_test_control(SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS, 
+        faultsimBeginBenign, faultsimEndBenign
+    );
+  }else{
+    assert(memfault.m.xMalloc);
+    rc = sqlite3_config(SQLITE_CONFIG_MALLOC, &memfault.m);
+    sqlite3_test_control(SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS, 0, 0);
+  }
+
+  if( rc==SQLITE_OK ){
+    memfault.isInstalled = 1;
+  }
+  return rc;
+}
+
+#ifdef SQLITE_TEST
+
+/*
+** This function is implemented in test1.c. Returns a pointer to a static
+** buffer containing the symbolic SQLite error code that corresponds to
+** the least-significant 8-bits of the integer passed as an argument.
+** For example:
+**
+**   sqlite3TestErrorName(1) -> "SQLITE_ERROR"
+*/
+const char *sqlite3TestErrorName(int);
+
+/*
+** Transform pointers to text and back again
+*/
+static void pointerToText(void *p, char *z){
+  static const char zHex[] = "0123456789abcdef";
+  int i, k;
+  unsigned int u;
+  sqlite3_uint64 n;
+  if( p==0 ){
+    strcpy(z, "0");
+    return;
+  }
+  if( sizeof(n)==sizeof(p) ){
+    memcpy(&n, &p, sizeof(p));
+  }else if( sizeof(u)==sizeof(p) ){
+    memcpy(&u, &p, sizeof(u));
+    n = u;
+  }else{
+    assert( 0 );
+  }
+  for(i=0, k=sizeof(p)*2-1; i<sizeof(p)*2; i++, k--){
+    z[k] = zHex[n&0xf];
+    n >>= 4;
+  }
+  z[sizeof(p)*2] = 0;
+}
+static int hexToInt(int h){
+  if( h>='0' && h<='9' ){
+    return h - '0';
+  }else if( h>='a' && h<='f' ){
+    return h - 'a' + 10;
+  }else{
+    return -1;
+  }
+}
+static int textToPointer(const char *z, void **pp){
+  sqlite3_uint64 n = 0;
+  int i;
+  unsigned int u;
+  for(i=0; i<sizeof(void*)*2 && z[0]; i++){
+    int v;
+    v = hexToInt(*z++);
+    if( v<0 ) return TCL_ERROR;
+    n = n*16 + v;
+  }
+  if( *z!=0 ) return TCL_ERROR;
+  if( sizeof(n)==sizeof(*pp) ){
+    memcpy(pp, &n, sizeof(n));
+  }else if( sizeof(u)==sizeof(*pp) ){
+    u = (unsigned int)n;
+    memcpy(pp, &u, sizeof(u));
+  }else{
+    assert( 0 );
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_malloc  NBYTES
+**
+** Raw test interface for sqlite3_malloc().
+*/
+static int test_malloc(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int nByte;
+  void *p;
+  char zOut[100];
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "NBYTES");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[1], &nByte) ) return TCL_ERROR;
+  p = sqlite3_malloc((unsigned)nByte);
+  pointerToText(p, zOut);
+  Tcl_AppendResult(interp, zOut, NULL);
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_realloc  PRIOR  NBYTES
+**
+** Raw test interface for sqlite3_realloc().
+*/
+static int test_realloc(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int nByte;
+  void *pPrior, *p;
+  char zOut[100];
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "PRIOR NBYTES");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[2], &nByte) ) return TCL_ERROR;
+  if( textToPointer(Tcl_GetString(objv[1]), &pPrior) ){
+    Tcl_AppendResult(interp, "bad pointer: ", Tcl_GetString(objv[1]), (char*)0);
+    return TCL_ERROR;
+  }
+  p = sqlite3_realloc(pPrior, (unsigned)nByte);
+  pointerToText(p, zOut);
+  Tcl_AppendResult(interp, zOut, NULL);
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_free  PRIOR
+**
+** Raw test interface for sqlite3_free().
+*/
+static int test_free(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  void *pPrior;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "PRIOR");
+    return TCL_ERROR;
+  }
+  if( textToPointer(Tcl_GetString(objv[1]), &pPrior) ){
+    Tcl_AppendResult(interp, "bad pointer: ", Tcl_GetString(objv[1]), (char*)0);
+    return TCL_ERROR;
+  }
+  sqlite3_free(pPrior);
+  return TCL_OK;
+}
+
+/*
+** These routines are in test_hexio.c
+*/
+int sqlite3TestHexToBin(const char *, int, char *);
+int sqlite3TestBinToHex(char*,int);
+
+/*
+** Usage:    memset  ADDRESS  SIZE  HEX
+**
+** Set a chunk of memory (obtained from malloc, probably) to a
+** specified hex pattern.
+*/
+static int test_memset(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  void *p;
+  int size, n, i;
+  char *zHex;
+  char *zOut;
+  char zBin[100];
+
+  if( objc!=4 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "ADDRESS SIZE HEX");
+    return TCL_ERROR;
+  }
+  if( textToPointer(Tcl_GetString(objv[1]), &p) ){
+    Tcl_AppendResult(interp, "bad pointer: ", Tcl_GetString(objv[1]), (char*)0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[2], &size) ){
+    return TCL_ERROR;
+  }
+  if( size<=0 ){
+    Tcl_AppendResult(interp, "size must be positive", (char*)0);
+    return TCL_ERROR;
+  }
+  zHex = Tcl_GetStringFromObj(objv[3], &n);
+  if( n>sizeof(zBin)*2 ) n = sizeof(zBin)*2;
+  n = sqlite3TestHexToBin(zHex, n, zBin);
+  if( n==0 ){
+    Tcl_AppendResult(interp, "no data", (char*)0);
+    return TCL_ERROR;
+  }
+  zOut = p;
+  for(i=0; i<size; i++){
+    zOut[i] = zBin[i%n];
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:    memget  ADDRESS  SIZE
+**
+** Return memory as hexadecimal text.
+*/
+static int test_memget(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  void *p;
+  int size, n;
+  char *zBin;
+  char zHex[100];
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "ADDRESS SIZE");
+    return TCL_ERROR;
+  }
+  if( textToPointer(Tcl_GetString(objv[1]), &p) ){
+    Tcl_AppendResult(interp, "bad pointer: ", Tcl_GetString(objv[1]), (char*)0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[2], &size) ){
+    return TCL_ERROR;
+  }
+  if( size<=0 ){
+    Tcl_AppendResult(interp, "size must be positive", (char*)0);
+    return TCL_ERROR;
+  }
+  zBin = p;
+  while( size>0 ){
+    if( size>(sizeof(zHex)-1)/2 ){
+      n = (sizeof(zHex)-1)/2;
+    }else{
+      n = size;
+    }
+    memcpy(zHex, zBin, n);
+    zBin += n;
+    size -= n;
+    sqlite3TestBinToHex(zHex, n);
+    Tcl_AppendResult(interp, zHex, (char*)0);
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_memory_used
+**
+** Raw test interface for sqlite3_memory_used().
+*/
+static int test_memory_used(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  Tcl_SetObjResult(interp, Tcl_NewWideIntObj(sqlite3_memory_used()));
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_memory_highwater ?RESETFLAG?
+**
+** Raw test interface for sqlite3_memory_highwater().
+*/
+static int test_memory_highwater(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int resetFlag = 0;
+  if( objc!=1 && objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "?RESET?");
+    return TCL_ERROR;
+  }
+  if( objc==2 ){
+    if( Tcl_GetBooleanFromObj(interp, objv[1], &resetFlag) ) return TCL_ERROR;
+  } 
+  Tcl_SetObjResult(interp, 
+     Tcl_NewWideIntObj(sqlite3_memory_highwater(resetFlag)));
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_memdebug_backtrace DEPTH
+**
+** Set the depth of backtracing.  If SQLITE_MEMDEBUG is not defined
+** then this routine is a no-op.
+*/
+static int test_memdebug_backtrace(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int depth;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DEPT");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[1], &depth) ) return TCL_ERROR;
+#ifdef SQLITE_MEMDEBUG
+  {
+    extern void sqlite3MemdebugBacktrace(int);
+    sqlite3MemdebugBacktrace(depth);
+  }
+#endif
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_memdebug_dump  FILENAME
+**
+** Write a summary of unfreed memory to FILENAME.
+*/
+static int test_memdebug_dump(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "FILENAME");
+    return TCL_ERROR;
+  }
+#if defined(SQLITE_MEMDEBUG) || defined(SQLITE_MEMORY_SIZE) \
+     || defined(SQLITE_POW2_MEMORY_SIZE)
+  {
+    extern void sqlite3MemdebugDump(const char*);
+    sqlite3MemdebugDump(Tcl_GetString(objv[1]));
+  }
+#endif
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_memdebug_malloc_count
+**
+** Return the total number of times malloc() has been called.
+*/
+static int test_memdebug_malloc_count(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int nMalloc = -1;
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+#if defined(SQLITE_MEMDEBUG)
+  {
+    extern int sqlite3MemdebugMallocCount();
+    nMalloc = sqlite3MemdebugMallocCount();
+  }
+#endif
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(nMalloc));
+  return TCL_OK;
+}
+
+
+/*
+** Usage:    sqlite3_memdebug_fail  COUNTER  ?OPTIONS?
+**
+** where options are:
+**
+**     -repeat    <count>
+**     -benigncnt <varname>
+**
+** Arrange for a simulated malloc() failure after COUNTER successes.
+** If a repeat count is specified, the fault is repeated that many
+** times.
+**
+** Each call to this routine overrides the prior counter value.
+** This routine returns the number of simulated failures that have
+** happened since the previous call to this routine.
+**
+** To disable simulated failures, use a COUNTER of -1.
+*/
+static int test_memdebug_fail(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int ii;
+  int iFail;
+  int nRepeat = 1;
+  Tcl_Obj *pBenignCnt = 0;
+  int nBenign;
+  int nFail = 0;
+
+  if( objc<2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "COUNTER ?OPTIONS?");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[1], &iFail) ) return TCL_ERROR;
+
+  for(ii=2; ii<objc; ii+=2){
+    int nOption;
+    char *zOption = Tcl_GetStringFromObj(objv[ii], &nOption);
+    char *zErr = 0;
+
+    if( nOption>1 && strncmp(zOption, "-repeat", nOption)==0 ){
+      if( ii==(objc-1) ){
+        zErr = "option requires an argument: ";
+      }else{
+        if( Tcl_GetIntFromObj(interp, objv[ii+1], &nRepeat) ){
+          return TCL_ERROR;
+        }
+      }
+    }else if( nOption>1 && strncmp(zOption, "-benigncnt", nOption)==0 ){
+      if( ii==(objc-1) ){
+        zErr = "option requires an argument: ";
+      }else{
+        pBenignCnt = objv[ii+1];
+      }
+    }else{
+      zErr = "unknown option: ";
+    }
+
+    if( zErr ){
+      Tcl_AppendResult(interp, zErr, zOption, 0);
+      return TCL_ERROR;
+    }
+  }
+  
+  nBenign = faultsimBenignFailures();
+  nFail = faultsimFailures();
+  faultsimConfig(iFail, nRepeat);
+
+  if( pBenignCnt ){
+    Tcl_ObjSetVar2(interp, pBenignCnt, 0, Tcl_NewIntObj(nBenign), 0);
+  }
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(nFail));
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_memdebug_pending
+**
+** Return the number of malloc() calls that will succeed before a 
+** simulated failure occurs. A negative return value indicates that
+** no malloc() failure is scheduled.
+*/
+static int test_memdebug_pending(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int nPending;
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+  nPending = faultsimPending();
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(nPending));
+  return TCL_OK;
+}
+
+
+/*
+** Usage:    sqlite3_memdebug_settitle TITLE
+**
+** Set a title string stored with each allocation.  The TITLE is
+** typically the name of the test that was running when the
+** allocation occurred.  The TITLE is stored with the allocation
+** and can be used to figure out which tests are leaking memory.
+**
+** Each title overwrite the previous.
+*/
+static int test_memdebug_settitle(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  const char *zTitle;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "TITLE");
+    return TCL_ERROR;
+  }
+  zTitle = Tcl_GetString(objv[1]);
+#ifdef SQLITE_MEMDEBUG
+  {
+    extern int sqlite3MemdebugSettitle(const char*);
+    sqlite3MemdebugSettitle(zTitle);
+  }
+#endif
+  return TCL_OK;
+}
+
+#define MALLOC_LOG_FRAMES 10 
+static Tcl_HashTable aMallocLog;
+static int mallocLogEnabled = 0;
+
+typedef struct MallocLog MallocLog;
+struct MallocLog {
+  int nCall;
+  int nByte;
+};
+
+#ifdef SQLITE_MEMDEBUG
+static void test_memdebug_callback(int nByte, int nFrame, void **aFrame){
+  if( mallocLogEnabled ){
+    MallocLog *pLog;
+    Tcl_HashEntry *pEntry;
+    int isNew;
+
+    int aKey[MALLOC_LOG_FRAMES];
+    int nKey = sizeof(int)*MALLOC_LOG_FRAMES;
+
+    memset(aKey, 0, nKey);
+    if( (sizeof(void*)*nFrame)<nKey ){
+      nKey = nFrame*sizeof(void*);
+    }
+    memcpy(aKey, aFrame, nKey);
+
+    pEntry = Tcl_CreateHashEntry(&aMallocLog, (const char *)aKey, &isNew);
+    if( isNew ){
+      pLog = (MallocLog *)Tcl_Alloc(sizeof(MallocLog));
+      memset(pLog, 0, sizeof(MallocLog));
+      Tcl_SetHashValue(pEntry, (ClientData)pLog);
+    }else{
+      pLog = (MallocLog *)Tcl_GetHashValue(pEntry);
+    }
+
+    pLog->nCall++;
+    pLog->nByte += nByte;
+  }
+}
+#endif /* SQLITE_MEMDEBUG */
+
+static void test_memdebug_log_clear(){
+  Tcl_HashSearch search;
+  Tcl_HashEntry *pEntry;
+  for(
+    pEntry=Tcl_FirstHashEntry(&aMallocLog, &search);
+    pEntry;
+    pEntry=Tcl_NextHashEntry(&search)
+  ){
+    MallocLog *pLog = (MallocLog *)Tcl_GetHashValue(pEntry);
+    Tcl_Free((char *)pLog);
+  }
+  Tcl_DeleteHashTable(&aMallocLog);
+  Tcl_InitHashTable(&aMallocLog, MALLOC_LOG_FRAMES);
+}
+
+static int test_memdebug_log(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  static int isInit = 0;
+  int iSub;
+
+  static const char *MB_strs[] = { "start", "stop", "dump", "clear", "sync" };
+  enum MB_enum { 
+      MB_LOG_START, MB_LOG_STOP, MB_LOG_DUMP, MB_LOG_CLEAR, MB_LOG_SYNC 
+  };
+
+  if( !isInit ){
+#ifdef SQLITE_MEMDEBUG
+    extern void sqlite3MemdebugBacktraceCallback(
+        void (*xBacktrace)(int, int, void **));
+    sqlite3MemdebugBacktraceCallback(test_memdebug_callback);
+#endif
+    Tcl_InitHashTable(&aMallocLog, MALLOC_LOG_FRAMES);
+    isInit = 1;
+  }
+
+  if( objc<2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SUB-COMMAND ...");
+  }
+  if( Tcl_GetIndexFromObj(interp, objv[1], MB_strs, "sub-command", 0, &iSub) ){
+    return TCL_ERROR;
+  }
+
+  switch( (enum MB_enum)iSub ){
+    case MB_LOG_START:
+      mallocLogEnabled = 1;
+      break;
+    case MB_LOG_STOP:
+      mallocLogEnabled = 0;
+      break;
+    case MB_LOG_DUMP: {
+      Tcl_HashSearch search;
+      Tcl_HashEntry *pEntry;
+      Tcl_Obj *pRet = Tcl_NewObj();
+
+      assert(sizeof(int)==sizeof(void*));
+
+      for(
+        pEntry=Tcl_FirstHashEntry(&aMallocLog, &search);
+        pEntry;
+        pEntry=Tcl_NextHashEntry(&search)
+      ){
+        Tcl_Obj *apElem[MALLOC_LOG_FRAMES+2];
+        MallocLog *pLog = (MallocLog *)Tcl_GetHashValue(pEntry);
+        int *aKey = (int *)Tcl_GetHashKey(&aMallocLog, pEntry);
+        int ii;
+  
+        apElem[0] = Tcl_NewIntObj(pLog->nCall);
+        apElem[1] = Tcl_NewIntObj(pLog->nByte);
+        for(ii=0; ii<MALLOC_LOG_FRAMES; ii++){
+          apElem[ii+2] = Tcl_NewIntObj(aKey[ii]);
+        }
+
+        Tcl_ListObjAppendElement(interp, pRet,
+            Tcl_NewListObj(MALLOC_LOG_FRAMES+2, apElem)
+        );
+      }
+
+      Tcl_SetObjResult(interp, pRet);
+      break;
+    }
+    case MB_LOG_CLEAR: {
+      test_memdebug_log_clear();
+      break;
+    }
+
+    case MB_LOG_SYNC: {
+#ifdef SQLITE_MEMDEBUG
+      extern void sqlite3MemdebugSync();
+      test_memdebug_log_clear();
+      mallocLogEnabled = 1;
+      sqlite3MemdebugSync();
+#endif
+      break;
+    }
+  }
+
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_config_scratch SIZE N
+**
+** Set the scratch memory buffer using SQLITE_CONFIG_SCRATCH.
+** The buffer is static and is of limited size.  N might be
+** adjusted downward as needed to accomodate the requested size.
+** The revised value of N is returned.
+**
+** A negative SIZE causes the buffer pointer to be NULL.
+*/
+static int test_config_scratch(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int sz, N, rc;
+  Tcl_Obj *pResult;
+  static char *buf = 0;
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SIZE N");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[1], &sz) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &N) ) return TCL_ERROR;
+  free(buf);
+  if( sz<0 ){
+    buf = 0;
+    rc = sqlite3_config(SQLITE_CONFIG_SCRATCH, 0, 0, 0);
+  }else{
+    buf = malloc( sz*N + 1 );
+    rc = sqlite3_config(SQLITE_CONFIG_SCRATCH, buf, sz, N);
+  }
+  pResult = Tcl_NewObj();
+  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(rc));
+  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(N));
+  Tcl_SetObjResult(interp, pResult);
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_config_pagecache SIZE N
+**
+** Set the page-cache memory buffer using SQLITE_CONFIG_PAGECACHE.
+** The buffer is static and is of limited size.  N might be
+** adjusted downward as needed to accomodate the requested size.
+** The revised value of N is returned.
+**
+** A negative SIZE causes the buffer pointer to be NULL.
+*/
+static int test_config_pagecache(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int sz, N, rc;
+  Tcl_Obj *pResult;
+  static char *buf = 0;
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SIZE N");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[1], &sz) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &N) ) return TCL_ERROR;
+  free(buf);
+  if( sz<0 ){
+    buf = 0;
+    rc = sqlite3_config(SQLITE_CONFIG_PAGECACHE, 0, 0, 0);
+  }else{
+    buf = malloc( sz*N );
+    rc = sqlite3_config(SQLITE_CONFIG_PAGECACHE, buf, sz, N);
+  }
+  pResult = Tcl_NewObj();
+  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(rc));
+  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(N));
+  Tcl_SetObjResult(interp, pResult);
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_config_memstatus BOOLEAN
+**
+** Enable or disable memory status reporting using SQLITE_CONFIG_MEMSTATUS.
+*/
+static int test_config_memstatus(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int enable, rc;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "BOOLEAN");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetBooleanFromObj(interp, objv[1], &enable) ) return TCL_ERROR;
+  rc = sqlite3_config(SQLITE_CONFIG_MEMSTATUS, enable);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_config_chunkalloc 
+**
+*/
+static int test_config_chunkalloc(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc;
+  int nThreshold;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "THRESHOLD");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[1], &nThreshold) ) return TCL_ERROR;
+  rc = sqlite3_config(SQLITE_CONFIG_CHUNKALLOC, nThreshold);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_config_lookaside  SIZE  COUNT
+**
+*/
+static int test_config_lookaside(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc;
+  int sz, cnt;
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SIZE COUNT");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[1], &sz) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &cnt) ) return TCL_ERROR;
+  rc = sqlite3_config(SQLITE_CONFIG_LOOKASIDE, sz, cnt);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return TCL_OK;
+}
+
+
+/*
+** Usage:    sqlite3_db_config_lookaside  CONNECTION  BUFID  SIZE  COUNT
+**
+** There are two static buffers with BUFID 1 and 2.   Each static buffer
+** is 10KB in size.  A BUFID of 0 indicates that the buffer should be NULL
+** which will cause sqlite3_db_config() to allocate space on its own.
+*/
+static int test_db_config_lookaside(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc;
+  int sz, cnt;
+  sqlite3 *db;
+  int bufid;
+  static char azBuf[2][10000];
+  int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
+  if( objc!=5 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "BUFID SIZE COUNT");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &bufid) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[3], &sz) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[4], &cnt) ) return TCL_ERROR;
+  if( bufid==0 ){
+    rc = sqlite3_db_config(db, SQLITE_DBCONFIG_LOOKASIDE, 0, sz, cnt);
+  }else if( bufid>=1 && bufid<=2 && sz*cnt<=sizeof(azBuf[0]) ){
+    rc = sqlite3_db_config(db, SQLITE_DBCONFIG_LOOKASIDE, azBuf[bufid], sz,cnt);
+  }else{
+    Tcl_AppendResult(interp, "illegal arguments - see documentation", (char*)0);
+    return TCL_ERROR;
+  }
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return TCL_OK;
+}
+
+/*
+** Usage:
+**
+**   sqlite3_config_heap NBYTE NMINALLOC
+*/
+static int test_config_heap(
+  void * clientData, 
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  static char *zBuf; /* Use this memory */
+  static int szBuf;  /* Bytes allocated for zBuf */
+  int nByte;         /* Size of buffer to pass to sqlite3_config() */
+  int nMinAlloc;     /* Size of minimum allocation */
+  int rc;            /* Return code of sqlite3_config() */
+
+  Tcl_Obj * CONST *aArg = &objv[1];
+  int nArg = objc-1;
+
+  if( nArg!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "NBYTE NMINALLOC");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, aArg[0], &nByte) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, aArg[1], &nMinAlloc) ) return TCL_ERROR;
+
+  if( nByte==0 ){
+    free( zBuf );
+    zBuf = 0;
+    szBuf = 0;
+    rc = sqlite3_config(SQLITE_CONFIG_HEAP, (void*)0, 0, 0);
+  }else{
+    zBuf = realloc(zBuf, nByte);
+    szBuf = nByte;
+    rc = sqlite3_config(SQLITE_CONFIG_HEAP, zBuf, nByte, nMinAlloc);
+  }
+
+  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  return TCL_OK;
+}
+
+/*
+** tclcmd:     sqlite3_config_error  [DB]
+**
+** Invoke sqlite3_config() or sqlite3_db_config() with invalid
+** opcodes and verify that they return errors.
+*/
+static int test_config_error(
+  void * clientData, 
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
+
+  if( objc!=2 && objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "[DB]");
+    return TCL_ERROR;
+  }
+  if( objc==2 ){
+    if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+    if( sqlite3_db_config(db, 99999)!=SQLITE_ERROR ){
+      Tcl_AppendResult(interp, 
+            "sqlite3_db_config(db, 99999) does not return SQLITE_ERROR",
+            (char*)0);
+      return TCL_ERROR;
+    }
+  }else{
+    if( sqlite3_config(99999)!=SQLITE_ERROR ){
+      Tcl_AppendResult(interp, 
+          "sqlite3_config(99999) does not return SQLITE_ERROR",
+          (char*)0);
+      return TCL_ERROR;
+    }
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:    
+**
+**   sqlite3_dump_memsys3  FILENAME
+**   sqlite3_dump_memsys5  FILENAME
+**
+** Write a summary of unfreed memsys3 allocations to FILENAME.
+*/
+static int test_dump_memsys3(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "FILENAME");
+    return TCL_ERROR;
+  }
+
+  switch( (int)clientData ){
+    case 3: {
+#ifdef SQLITE_ENABLE_MEMSYS3
+      extern void sqlite3Memsys3Dump(const char*);
+      sqlite3Memsys3Dump(Tcl_GetString(objv[1]));
+      break;
+#endif
+    }
+    case 5: {
+#ifdef SQLITE_ENABLE_MEMSYS5
+      extern void sqlite3Memsys5Dump(const char*);
+      sqlite3Memsys5Dump(Tcl_GetString(objv[1]));
+      break;
+#endif
+    }
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_status  OPCODE  RESETFLAG
+**
+** Return a list of three elements which are the sqlite3_status() return
+** code, the current value, and the high-water mark value.
+*/
+static int test_status(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc, iValue, mxValue;
+  int i, op, resetFlag;
+  const char *zOpName;
+  static const struct {
+    const char *zName;
+    int op;
+  } aOp[] = {
+    { "SQLITE_STATUS_MEMORY_USED",         SQLITE_STATUS_MEMORY_USED         },
+    { "SQLITE_STATUS_MALLOC_SIZE",         SQLITE_STATUS_MALLOC_SIZE         },
+    { "SQLITE_STATUS_PAGECACHE_USED",      SQLITE_STATUS_PAGECACHE_USED      },
+    { "SQLITE_STATUS_PAGECACHE_OVERFLOW",  SQLITE_STATUS_PAGECACHE_OVERFLOW  },
+    { "SQLITE_STATUS_PAGECACHE_SIZE",      SQLITE_STATUS_PAGECACHE_SIZE      },
+    { "SQLITE_STATUS_SCRATCH_USED",        SQLITE_STATUS_SCRATCH_USED        },
+    { "SQLITE_STATUS_SCRATCH_OVERFLOW",    SQLITE_STATUS_SCRATCH_OVERFLOW    },
+    { "SQLITE_STATUS_SCRATCH_SIZE",        SQLITE_STATUS_SCRATCH_SIZE        },
+    { "SQLITE_STATUS_PARSER_STACK",        SQLITE_STATUS_PARSER_STACK        },
+  };
+  Tcl_Obj *pResult;
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "PARAMETER RESETFLAG");
+    return TCL_ERROR;
+  }
+  zOpName = Tcl_GetString(objv[1]);
+  for(i=0; i<ArraySize(aOp); i++){
+    if( strcmp(aOp[i].zName, zOpName)==0 ){
+      op = aOp[i].op;
+      break;
+    }
+  }
+  if( i>=ArraySize(aOp) ){
+    if( Tcl_GetIntFromObj(interp, objv[1], &op) ) return TCL_ERROR;
+  }
+  if( Tcl_GetBooleanFromObj(interp, objv[2], &resetFlag) ) return TCL_ERROR;
+  iValue = 0;
+  mxValue = 0;
+  rc = sqlite3_status(op, &iValue, &mxValue, resetFlag);
+  pResult = Tcl_NewObj();
+  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(rc));
+  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(iValue));
+  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(mxValue));
+  Tcl_SetObjResult(interp, pResult);
+  return TCL_OK;
+}
+
+/*
+** Usage:    sqlite3_db_status  DATABASE  OPCODE  RESETFLAG
+**
+** Return a list of three elements which are the sqlite3_db_status() return
+** code, the current value, and the high-water mark value.
+*/
+static int test_db_status(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc, iValue, mxValue;
+  int i, op, resetFlag;
+  const char *zOpName;
+  sqlite3 *db;
+  int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
+  static const struct {
+    const char *zName;
+    int op;
+  } aOp[] = {
+    { "SQLITE_DBSTATUS_LOOKASIDE_USED",    SQLITE_DBSTATUS_LOOKASIDE_USED   },
+  };
+  Tcl_Obj *pResult;
+  if( objc!=4 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "PARAMETER RESETFLAG");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  zOpName = Tcl_GetString(objv[2]);
+  for(i=0; i<ArraySize(aOp); i++){
+    if( strcmp(aOp[i].zName, zOpName)==0 ){
+      op = aOp[i].op;
+      break;
+    }
+  }
+  if( i>=ArraySize(aOp) ){
+    if( Tcl_GetIntFromObj(interp, objv[2], &op) ) return TCL_ERROR;
+  }
+  if( Tcl_GetBooleanFromObj(interp, objv[3], &resetFlag) ) return TCL_ERROR;
+  iValue = 0;
+  mxValue = 0;
+  rc = sqlite3_db_status(db, op, &iValue, &mxValue, resetFlag);
+  pResult = Tcl_NewObj();
+  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(rc));
+  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(iValue));
+  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(mxValue));
+  Tcl_SetObjResult(interp, pResult);
+  return TCL_OK;
+}
+
+/*
+** install_malloc_faultsim BOOLEAN
+*/
+static int test_install_malloc_faultsim(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc;
+  int isInstall;
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "BOOLEAN");
+    return TCL_ERROR;
+  }
+  if( TCL_OK!=Tcl_GetBooleanFromObj(interp, objv[1], &isInstall) ){
+    return TCL_ERROR;
+  }
+  rc = faultsimInstall(isInstall);
+  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  return TCL_OK;
+}
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest_malloc_Init(Tcl_Interp *interp){
+  static struct {
+     char *zName;
+     Tcl_ObjCmdProc *xProc;
+     int clientData;
+  } aObjCmd[] = {
+     { "sqlite3_malloc",             test_malloc                   ,0 },
+     { "sqlite3_realloc",            test_realloc                  ,0 },
+     { "sqlite3_free",               test_free                     ,0 },
+     { "memset",                     test_memset                   ,0 },
+     { "memget",                     test_memget                   ,0 },
+     { "sqlite3_memory_used",        test_memory_used              ,0 },
+     { "sqlite3_memory_highwater",   test_memory_highwater         ,0 },
+     { "sqlite3_memdebug_backtrace", test_memdebug_backtrace       ,0 },
+     { "sqlite3_memdebug_dump",      test_memdebug_dump            ,0 },
+     { "sqlite3_memdebug_fail",      test_memdebug_fail            ,0 },
+     { "sqlite3_memdebug_pending",   test_memdebug_pending         ,0 },
+     { "sqlite3_memdebug_settitle",  test_memdebug_settitle        ,0 },
+     { "sqlite3_memdebug_malloc_count", test_memdebug_malloc_count ,0 },
+     { "sqlite3_memdebug_log",       test_memdebug_log             ,0 },
+     { "sqlite3_config_scratch",     test_config_scratch           ,0 },
+     { "sqlite3_config_pagecache",   test_config_pagecache         ,0 },
+     { "sqlite3_status",             test_status                   ,0 },
+     { "sqlite3_db_status",          test_db_status                ,0 },
+     { "install_malloc_faultsim",    test_install_malloc_faultsim  ,0 },
+     { "sqlite3_config_heap",        test_config_heap              ,0 },
+     { "sqlite3_config_memstatus",   test_config_memstatus         ,0 },
+     { "sqlite3_config_chunkalloc",  test_config_chunkalloc        ,0 },
+     { "sqlite3_config_lookaside",   test_config_lookaside         ,0 },
+     { "sqlite3_config_error",       test_config_error             ,0 },
+     { "sqlite3_db_config_lookaside",test_db_config_lookaside      ,0 },
+     { "sqlite3_dump_memsys3",       test_dump_memsys3             ,3 },
+     { "sqlite3_dump_memsys5",       test_dump_memsys3             ,5 }
+  };
+  int i;
+  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
+    ClientData c = (ClientData)aObjCmd[i].clientData;
+    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, aObjCmd[i].xProc, c, 0);
+  }
+  return TCL_OK;
+}
+#endif
diff --git a/third_party/sqlite/src/test_md5.c b/third_party/sqlite/src/test_md5.c
new file mode 100755
index 0000000..0470d9f
--- /dev/null
+++ b/third_party/sqlite/src/test_md5.c
@@ -0,0 +1,392 @@
+/*
+** SQLite uses this code for testing only.  It is not a part of
+** the SQLite library.  This file implements two new TCL commands
+** "md5" and "md5file" that compute md5 checksums on arbitrary text
+** and on complete files.  These commands are used by the "testfixture"
+** program to help verify the correct operation of the SQLite library.
+**
+** The original use of these TCL commands was to test the ROLLBACK
+** feature of SQLite.  First compute the MD5-checksum of the database.
+** Then make some changes but rollback the changes rather than commit
+** them.  Compute a second MD5-checksum of the file and verify that the
+** two checksums are the same.  Such is the original use of this code.
+** New uses may have been added since this comment was written.
+**
+** $Id: test_md5.c,v 1.8 2008/05/16 04:51:55 danielk1977 Exp $
+*/
+/*
+ * This code implements the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest.  This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ *
+ * To compute the message digest of a chunk of bytes, declare an
+ * MD5Context structure, pass it to MD5Init, call MD5Update as
+ * needed on buffers full of bytes, and then call MD5Final, which
+ * will fill a supplied 16-byte array with the digest.
+ */
+#include <tcl.h>
+#include <string.h>
+#include "sqlite3.h"
+
+/*
+ * If compiled on a machine that doesn't have a 32-bit integer,
+ * you just set "uint32" to the appropriate datatype for an
+ * unsigned 32-bit integer.  For example:
+ *
+ *       cc -Duint32='unsigned long' md5.c
+ *
+ */
+#ifndef uint32
+#  define uint32 unsigned int
+#endif
+
+struct Context {
+  int isInit;
+  uint32 buf[4];
+  uint32 bits[2];
+  unsigned char in[64];
+};
+typedef struct Context MD5Context;
+
+/*
+ * Note: this code is harmless on little-endian machines.
+ */
+static void byteReverse (unsigned char *buf, unsigned longs){
+        uint32 t;
+        do {
+                t = (uint32)((unsigned)buf[3]<<8 | buf[2]) << 16 |
+                            ((unsigned)buf[1]<<8 | buf[0]);
+                *(uint32 *)buf = t;
+                buf += 4;
+        } while (--longs);
+}
+/* The four core functions - F1 is optimized somewhat */
+
+/* #define F1(x, y, z) (x & y | ~x & z) */
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+/* This is the central step in the MD5 algorithm. */
+#define MD5STEP(f, w, x, y, z, data, s) \
+        ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
+
+/*
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data.  MD5Update blocks
+ * the data and converts bytes into longwords for this routine.
+ */
+static void MD5Transform(uint32 buf[4], const uint32 in[16]){
+        register uint32 a, b, c, d;
+
+        a = buf[0];
+        b = buf[1];
+        c = buf[2];
+        d = buf[3];
+
+        MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478,  7);
+        MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
+        MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
+        MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
+        MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf,  7);
+        MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
+        MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
+        MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
+        MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8,  7);
+        MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
+        MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
+        MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
+        MD5STEP(F1, a, b, c, d, in[12]+0x6b901122,  7);
+        MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
+        MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
+        MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);
+
+        MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562,  5);
+        MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340,  9);
+        MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
+        MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
+        MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d,  5);
+        MD5STEP(F2, d, a, b, c, in[10]+0x02441453,  9);
+        MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
+        MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
+        MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6,  5);
+        MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6,  9);
+        MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
+        MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
+        MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905,  5);
+        MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8,  9);
+        MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
+        MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);
+
+        MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942,  4);
+        MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
+        MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
+        MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
+        MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44,  4);
+        MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
+        MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
+        MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
+        MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6,  4);
+        MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
+        MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
+        MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
+        MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039,  4);
+        MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
+        MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
+        MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);
+
+        MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244,  6);
+        MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
+        MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
+        MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
+        MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3,  6);
+        MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
+        MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
+        MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
+        MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f,  6);
+        MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
+        MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
+        MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
+        MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82,  6);
+        MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
+        MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
+        MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);
+
+        buf[0] += a;
+        buf[1] += b;
+        buf[2] += c;
+        buf[3] += d;
+}
+
+/*
+ * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
+ * initialization constants.
+ */
+static void MD5Init(MD5Context *ctx){
+        ctx->isInit = 1;
+        ctx->buf[0] = 0x67452301;
+        ctx->buf[1] = 0xefcdab89;
+        ctx->buf[2] = 0x98badcfe;
+        ctx->buf[3] = 0x10325476;
+        ctx->bits[0] = 0;
+        ctx->bits[1] = 0;
+}
+
+/*
+ * Update context to reflect the concatenation of another buffer full
+ * of bytes.
+ */
+static 
+void MD5Update(MD5Context *pCtx, const unsigned char *buf, unsigned int len){
+        struct Context *ctx = (struct Context *)pCtx;
+        uint32 t;
+
+        /* Update bitcount */
+
+        t = ctx->bits[0];
+        if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
+                ctx->bits[1]++; /* Carry from low to high */
+        ctx->bits[1] += len >> 29;
+
+        t = (t >> 3) & 0x3f;    /* Bytes already in shsInfo->data */
+
+        /* Handle any leading odd-sized chunks */
+
+        if ( t ) {
+                unsigned char *p = (unsigned char *)ctx->in + t;
+
+                t = 64-t;
+                if (len < t) {
+                        memcpy(p, buf, len);
+                        return;
+                }
+                memcpy(p, buf, t);
+                byteReverse(ctx->in, 16);
+                MD5Transform(ctx->buf, (uint32 *)ctx->in);
+                buf += t;
+                len -= t;
+        }
+
+        /* Process data in 64-byte chunks */
+
+        while (len >= 64) {
+                memcpy(ctx->in, buf, 64);
+                byteReverse(ctx->in, 16);
+                MD5Transform(ctx->buf, (uint32 *)ctx->in);
+                buf += 64;
+                len -= 64;
+        }
+
+        /* Handle any remaining bytes of data. */
+
+        memcpy(ctx->in, buf, len);
+}
+
+/*
+ * Final wrapup - pad to 64-byte boundary with the bit pattern 
+ * 1 0* (64-bit count of bits processed, MSB-first)
+ */
+static void MD5Final(unsigned char digest[16], MD5Context *pCtx){
+        struct Context *ctx = (struct Context *)pCtx;
+        unsigned count;
+        unsigned char *p;
+
+        /* Compute number of bytes mod 64 */
+        count = (ctx->bits[0] >> 3) & 0x3F;
+
+        /* Set the first char of padding to 0x80.  This is safe since there is
+           always at least one byte free */
+        p = ctx->in + count;
+        *p++ = 0x80;
+
+        /* Bytes of padding needed to make 64 bytes */
+        count = 64 - 1 - count;
+
+        /* Pad out to 56 mod 64 */
+        if (count < 8) {
+                /* Two lots of padding:  Pad the first block to 64 bytes */
+                memset(p, 0, count);
+                byteReverse(ctx->in, 16);
+                MD5Transform(ctx->buf, (uint32 *)ctx->in);
+
+                /* Now fill the next block with 56 bytes */
+                memset(ctx->in, 0, 56);
+        } else {
+                /* Pad block to 56 bytes */
+                memset(p, 0, count-8);
+        }
+        byteReverse(ctx->in, 14);
+
+        /* Append length in bits and transform */
+        ((uint32 *)ctx->in)[ 14 ] = ctx->bits[0];
+        ((uint32 *)ctx->in)[ 15 ] = ctx->bits[1];
+
+        MD5Transform(ctx->buf, (uint32 *)ctx->in);
+        byteReverse((unsigned char *)ctx->buf, 4);
+        memcpy(digest, ctx->buf, 16);
+        memset(ctx, 0, sizeof(ctx));    /* In case it is sensitive */
+}
+
+/*
+** Convert a digest into base-16.  digest should be declared as
+** "unsigned char digest[16]" in the calling function.  The MD5
+** digest is stored in the first 16 bytes.  zBuf should
+** be "char zBuf[33]".
+*/
+static void DigestToBase16(unsigned char *digest, char *zBuf){
+  static char const zEncode[] = "0123456789abcdef";
+  int i, j;
+
+  for(j=i=0; i<16; i++){
+    int a = digest[i];
+    zBuf[j++] = zEncode[(a>>4)&0xf];
+    zBuf[j++] = zEncode[a & 0xf];
+  }
+  zBuf[j] = 0;
+}
+
+/*
+** A TCL command for md5.  The argument is the text to be hashed.  The
+** Result is the hash in base64.  
+*/
+static int md5_cmd(void*cd, Tcl_Interp *interp, int argc, const char **argv){
+  MD5Context ctx;
+  unsigned char digest[16];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0], 
+        " TEXT\"", 0);
+    return TCL_ERROR;
+  }
+  MD5Init(&ctx);
+  MD5Update(&ctx, (unsigned char*)argv[1], (unsigned)strlen(argv[1]));
+  MD5Final(digest, &ctx);
+  DigestToBase16(digest, interp->result);
+  return TCL_OK;
+}
+
+/*
+** A TCL command to take the md5 hash of a file.  The argument is the
+** name of the file.
+*/
+static int md5file_cmd(void*cd, Tcl_Interp*interp, int argc, const char **argv){
+  FILE *in;
+  MD5Context ctx;
+  unsigned char digest[16];
+  char zBuf[10240];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0], 
+        " FILENAME\"", 0);
+    return TCL_ERROR;
+  }
+  in = fopen(argv[1],"rb");
+  if( in==0 ){
+    Tcl_AppendResult(interp,"unable to open file \"", argv[1], 
+         "\" for reading", 0);
+    return TCL_ERROR;
+  }
+  MD5Init(&ctx);
+  for(;;){
+    int n;
+    n = fread(zBuf, 1, sizeof(zBuf), in);
+    if( n<=0 ) break;
+    MD5Update(&ctx, (unsigned char*)zBuf, (unsigned)n);
+  }
+  fclose(in);
+  MD5Final(digest, &ctx);
+  DigestToBase16(digest, interp->result);
+  return TCL_OK;
+}
+
+/*
+** Register the two TCL commands above with the TCL interpreter.
+*/
+int Md5_Init(Tcl_Interp *interp){
+  Tcl_CreateCommand(interp, "md5", (Tcl_CmdProc*)md5_cmd, 0, 0);
+  Tcl_CreateCommand(interp, "md5file", (Tcl_CmdProc*)md5file_cmd, 0, 0);
+  return TCL_OK;
+}
+
+/*
+** During testing, the special md5sum() aggregate function is available.
+** inside SQLite.  The following routines implement that function.
+*/
+static void md5step(sqlite3_context *context, int argc, sqlite3_value **argv){
+  MD5Context *p;
+  int i;
+  if( argc<1 ) return;
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  if( p==0 ) return;
+  if( !p->isInit ){
+    MD5Init(p);
+  }
+  for(i=0; i<argc; i++){
+    const char *zData = (char*)sqlite3_value_text(argv[i]);
+    if( zData ){
+      MD5Update(p, (unsigned char*)zData, strlen(zData));
+    }
+  }
+}
+static void md5finalize(sqlite3_context *context){
+  MD5Context *p;
+  unsigned char digest[16];
+  char zBuf[33];
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  MD5Final(digest,p);
+  DigestToBase16(digest, zBuf);
+  sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
+}
+int Md5_Register(sqlite3 *db){
+  int rc = sqlite3_create_function(db, "md5sum", -1, SQLITE_UTF8, 0, 0, 
+                                 md5step, md5finalize);
+  sqlite3_overload_function(db, "md5sum", -1);  /* To exercise this API */
+  return rc;
+}
diff --git a/third_party/sqlite/src/test_mutex.c b/third_party/sqlite/src/test_mutex.c
new file mode 100755
index 0000000..571f81a
--- /dev/null
+++ b/third_party/sqlite/src/test_mutex.c
@@ -0,0 +1,387 @@
+/*
+** 2008 June 18
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** 
+** $Id: test_mutex.c,v 1.11 2008/07/19 13:43:24 danielk1977 Exp $
+*/
+
+#include "tcl.h"
+#include "sqlite3.h"
+#include "sqliteInt.h"
+#include <stdlib.h>
+#include <assert.h>
+#include <string.h>
+
+/* defined in test1.c */
+const char *sqlite3TestErrorName(int);
+
+/* A countable mutex */
+struct sqlite3_mutex {
+  sqlite3_mutex *pReal;
+  int eType;
+};
+
+/* State variables */
+static struct test_mutex_globals {
+  int isInstalled;              /* True if installed */
+  int disableInit;              /* True to cause sqlite3_initalize() to fail */
+  int disableTry;               /* True to force sqlite3_mutex_try() to fail */
+  int isInit;                   /* True if initialized */
+  sqlite3_mutex_methods m;      /* Interface to "real" mutex system */
+  int aCounter[8];              /* Number of grabs of each type of mutex */
+  sqlite3_mutex aStatic[6];     /* The six static mutexes */
+} g;
+
+/* Return true if the countable mutex is currently held */
+static int counterMutexHeld(sqlite3_mutex *p){
+  return g.m.xMutexHeld(p->pReal);
+}
+
+/* Return true if the countable mutex is not currently held */
+static int counterMutexNotheld(sqlite3_mutex *p){
+  return g.m.xMutexNotheld(p->pReal);
+}
+
+/* Initialize the countable mutex interface
+** Or, if g.disableInit is non-zero, then do not initialize but instead
+** return the value of g.disableInit as the result code.  This can be used
+** to simulate an initialization failure.
+*/
+static int counterMutexInit(void){ 
+  int rc;
+  if( g.disableInit ) return g.disableInit;
+  rc = g.m.xMutexInit();
+  g.isInit = 1;
+  return rc;
+}
+
+/*
+** Uninitialize the mutex subsystem
+*/
+static int counterMutexEnd(void){ 
+  g.isInit = 0;
+  return g.m.xMutexEnd();
+}
+
+/*
+** Allocate a countable mutex
+*/
+static sqlite3_mutex *counterMutexAlloc(int eType){
+  sqlite3_mutex *pReal;
+  sqlite3_mutex *pRet = 0;
+
+  assert( g.isInit );
+  assert(eType<8 && eType>=0);
+
+  pReal = g.m.xMutexAlloc(eType);
+  if( !pReal ) return 0;
+
+  if( eType==SQLITE_MUTEX_FAST || eType==SQLITE_MUTEX_RECURSIVE ){
+    pRet = (sqlite3_mutex *)malloc(sizeof(sqlite3_mutex));
+  }else{
+    pRet = &g.aStatic[eType-2];
+  }
+
+  pRet->eType = eType;
+  pRet->pReal = pReal;
+  return pRet;
+}
+
+/*
+** Free a countable mutex
+*/
+static void counterMutexFree(sqlite3_mutex *p){
+  assert( g.isInit );
+  g.m.xMutexFree(p->pReal);
+  if( p->eType==SQLITE_MUTEX_FAST || p->eType==SQLITE_MUTEX_RECURSIVE ){
+    free(p);
+  }
+}
+
+/*
+** Enter a countable mutex.  Block until entry is safe.
+*/
+static void counterMutexEnter(sqlite3_mutex *p){
+  assert( g.isInit );
+  g.aCounter[p->eType]++;
+  g.m.xMutexEnter(p->pReal);
+}
+
+/*
+** Try to enter a mutex.  Return true on success.
+*/
+static int counterMutexTry(sqlite3_mutex *p){
+  assert( g.isInit );
+  g.aCounter[p->eType]++;
+  if( g.disableTry ) return SQLITE_BUSY;
+  return g.m.xMutexTry(p->pReal);
+}
+
+/* Leave a mutex
+*/
+static void counterMutexLeave(sqlite3_mutex *p){
+  assert( g.isInit );
+  g.m.xMutexLeave(p->pReal);
+}
+
+/*
+** sqlite3_shutdown
+*/
+static int test_shutdown(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc;
+
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+
+  rc = sqlite3_shutdown();
+  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  return TCL_OK;
+}
+
+/*
+** sqlite3_initialize
+*/
+static int test_initialize(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc;
+
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+
+  rc = sqlite3_initialize();
+  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  return TCL_OK;
+}
+
+/*
+** install_mutex_counters BOOLEAN
+*/
+static int test_install_mutex_counters(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc = SQLITE_OK;
+  int isInstall;
+
+  sqlite3_mutex_methods counter_methods = {
+    counterMutexInit,
+    counterMutexEnd,
+    counterMutexAlloc,
+    counterMutexFree,
+    counterMutexEnter,
+    counterMutexTry,
+    counterMutexLeave,
+    counterMutexHeld,
+    counterMutexNotheld
+  };
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "BOOLEAN");
+    return TCL_ERROR;
+  }
+  if( TCL_OK!=Tcl_GetBooleanFromObj(interp, objv[1], &isInstall) ){
+    return TCL_ERROR;
+  }
+
+  assert(isInstall==0 || isInstall==1);
+  assert(g.isInstalled==0 || g.isInstalled==1);
+  if( isInstall==g.isInstalled ){
+    Tcl_AppendResult(interp, "mutex counters are ", 0);
+    Tcl_AppendResult(interp, isInstall?"already installed":"not installed", 0);
+    return TCL_ERROR;
+  }
+
+  if( isInstall ){
+    assert( g.m.xMutexAlloc==0 );
+    rc = sqlite3_config(SQLITE_CONFIG_GETMUTEX, &g.m);
+    if( rc==SQLITE_OK ){
+      sqlite3_config(SQLITE_CONFIG_MUTEX, &counter_methods);
+    }
+    g.disableTry = 0;
+  }else{
+    assert( g.m.xMutexAlloc );
+    rc = sqlite3_config(SQLITE_CONFIG_MUTEX, &g.m);
+    memset(&g.m, 0, sizeof(sqlite3_mutex_methods));
+  }
+
+  if( rc==SQLITE_OK ){
+    g.isInstalled = isInstall;
+  }
+
+  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  return TCL_OK;
+}
+
+/*
+** read_mutex_counters
+*/
+static int test_read_mutex_counters(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  Tcl_Obj *pRet;
+  int ii;
+  char *aName[8] = {
+    "fast",        "recursive",   "static_master", "static_mem", 
+    "static_mem2", "static_prng", "static_lru",    "static_lru2"
+  };
+
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+
+  pRet = Tcl_NewObj();
+  Tcl_IncrRefCount(pRet);
+  for(ii=0; ii<8; ii++){
+    Tcl_ListObjAppendElement(interp, pRet, Tcl_NewStringObj(aName[ii], -1));
+    Tcl_ListObjAppendElement(interp, pRet, Tcl_NewIntObj(g.aCounter[ii]));
+  }
+  Tcl_SetObjResult(interp, pRet);
+  Tcl_DecrRefCount(pRet);
+
+  return TCL_OK;
+}
+
+/*
+** clear_mutex_counters
+*/
+static int test_clear_mutex_counters(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int ii;
+
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+
+  for(ii=0; ii<8; ii++){
+    g.aCounter[ii] = 0;
+  }
+  return TCL_OK;
+}
+
+/*
+** Create and free a mutex.  Return the mutex pointer.  The pointer
+** will be invalid since the mutex has already been freed.  The
+** return pointer just checks to see if the mutex really was allocated.
+*/
+static int test_alloc_mutex(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#if SQLITE_THREADSAFE
+  sqlite3_mutex *p = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
+  char zBuf[100];
+  sqlite3_mutex_free(p);
+  sqlite3_snprintf(sizeof(zBuf), zBuf, "%p", p);
+  Tcl_AppendResult(interp, zBuf, (char*)0);
+#endif
+  return TCL_OK;
+}
+
+/*
+** sqlite3_config OPTION
+**
+** OPTION can be either one of the keywords:
+**
+**            SQLITE_CONFIG_SINGLETHREAD
+**            SQLITE_CONFIG_MULTITHREAD
+**            SQLITE_CONFIG_SERIALIZED
+**
+** Or OPTION can be an raw integer.
+*/
+static int test_config(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  struct ConfigOption {
+    const char *zName;
+    int iValue;
+  } aOpt[] = {
+    {"singlethread", SQLITE_CONFIG_SINGLETHREAD},
+    {"multithread",  SQLITE_CONFIG_MULTITHREAD},
+    {"serialized",   SQLITE_CONFIG_SERIALIZED},
+    {0, 0}
+  };
+  int s = sizeof(struct ConfigOption);
+  int i;
+  int rc;
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+
+  if( Tcl_GetIndexFromObjStruct(interp, objv[1], aOpt, s, "flag", 0, &i) ){
+    if( Tcl_GetIntFromObj(interp, objv[1], &i) ){
+      return TCL_ERROR;
+    }
+  }else{
+    i = aOpt[i].iValue;
+  }
+
+  rc = sqlite3_config(i);
+  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  return TCL_OK;
+}
+
+int Sqlitetest_mutex_Init(Tcl_Interp *interp){
+  static struct {
+    char *zName;
+    Tcl_ObjCmdProc *xProc;
+  } aCmd[] = {
+    { "sqlite3_shutdown",        (Tcl_ObjCmdProc*)test_shutdown },
+    { "sqlite3_initialize",      (Tcl_ObjCmdProc*)test_initialize },
+    { "sqlite3_config",          (Tcl_ObjCmdProc*)test_config },
+
+    { "alloc_dealloc_mutex",     (Tcl_ObjCmdProc*)test_alloc_mutex },
+    { "install_mutex_counters",  (Tcl_ObjCmdProc*)test_install_mutex_counters },
+    { "read_mutex_counters",     (Tcl_ObjCmdProc*)test_read_mutex_counters },
+    { "clear_mutex_counters",    (Tcl_ObjCmdProc*)test_clear_mutex_counters },
+  };
+  int i;
+  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
+    Tcl_CreateObjCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
+  }
+  memset(&g, 0, sizeof(g));
+
+  Tcl_LinkVar(interp, "disable_mutex_init", 
+              (char*)&g.disableInit, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "disable_mutex_try", 
+              (char*)&g.disableTry, TCL_LINK_INT);
+  return SQLITE_OK;
+}
diff --git a/third_party/sqlite/src/test_onefile.c b/third_party/sqlite/src/test_onefile.c
new file mode 100755
index 0000000..c8cc43c
--- /dev/null
+++ b/third_party/sqlite/src/test_onefile.c
@@ -0,0 +1,822 @@
+/*
+** 2007 September 14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** $Id: test_onefile.c,v 1.9 2008/06/26 10:54:12 danielk1977 Exp $
+**
+** OVERVIEW:
+**
+**   This file contains some example code demonstrating how the SQLite 
+**   vfs feature can be used to have SQLite operate directly on an 
+**   embedded media, without using an intermediate file system.
+**
+**   Because this is only a demo designed to run on a workstation, the
+**   underlying media is simulated using a regular file-system file. The
+**   size of the file is fixed when it is first created (default size 10 MB).
+**   From SQLite's point of view, this space is used to store a single
+**   database file and the journal file. 
+**
+**   Any statement journal created is stored in volatile memory obtained 
+**   from sqlite3_malloc(). Any attempt to create a temporary database file 
+**   will fail (SQLITE_IOERR). To prevent SQLite from attempting this,
+**   it should be configured to store all temporary database files in 
+**   main memory (see pragma "temp_store" or the SQLITE_TEMP_STORE compile 
+**   time option).
+**
+** ASSUMPTIONS:
+**
+**   After it has been created, the blob file is accessed using the
+**   following three functions only:
+**
+**       mediaRead();            - Read a 512 byte block from the file.
+**       mediaWrite();           - Write a 512 byte block to the file.
+**       mediaSync();            - Tell the media hardware to sync.
+**
+**   It is assumed that these can be easily implemented by any "real"
+**   media vfs driver adapting this code.
+**
+** FILE FORMAT:
+**
+**   The basic principle is that the "database file" is stored at the
+**   beginning of the 10 MB blob and grows in a forward direction. The 
+**   "journal file" is stored at the end of the 10MB blob and grows
+**   in the reverse direction. If, during a transaction, insufficient
+**   space is available to expand either the journal or database file,
+**   an SQLITE_FULL error is returned. The database file is never allowed
+**   to consume more than 90% of the blob space. If SQLite tries to
+**   create a file larger than this, SQLITE_FULL is returned.
+**
+**   No allowance is made for "wear-leveling", as is required by.
+**   embedded devices in the absence of equivalent hardware features.
+**
+**   The first 512 block byte of the file is reserved for storing the
+**   size of the "database file". It is updated as part of the sync()
+**   operation. On startup, it can only be trusted if no journal file
+**   exists. If a journal-file does exist, then it stores the real size
+**   of the database region. The second and subsequent blocks store the 
+**   actual database content.
+**
+**   The size of the "journal file" is not stored persistently in the 
+**   file. When the system is running, the size of the journal file is
+**   stored in volatile memory. When recovering from a crash, this vfs
+**   reports a very large size for the journal file. The normal journal
+**   header and checksum mechanisms serve to prevent SQLite from 
+**   processing any data that lies past the logical end of the journal.
+**
+**   When SQLite calls OsDelete() to delete the journal file, the final
+**   512 bytes of the blob (the area containing the first journal header)
+**   are zeroed.
+**
+** LOCKING:
+**
+**   File locking is a no-op. Only one connection may be open at any one
+**   time using this demo vfs.
+*/
+
+#include "sqlite3.h"
+#include <assert.h>
+#include <string.h>
+
+/*
+** Maximum pathname length supported by the fs backend.
+*/
+#define BLOCKSIZE 512
+#define BLOBSIZE 10485760
+
+/*
+** Name used to identify this VFS.
+*/
+#define FS_VFS_NAME "fs"
+
+typedef struct fs_real_file fs_real_file;
+struct fs_real_file {
+  sqlite3_file *pFile;
+  const char *zName;
+  int nDatabase;              /* Current size of database region */
+  int nJournal;               /* Current size of journal region */
+  int nBlob;                  /* Total size of allocated blob */
+  int nRef;                   /* Number of pointers to this structure */
+  fs_real_file *pNext;
+  fs_real_file **ppThis;
+};
+
+typedef struct fs_file fs_file;
+struct fs_file {
+  sqlite3_file base;
+  int eType;
+  fs_real_file *pReal;
+};
+
+typedef struct tmp_file tmp_file;
+struct tmp_file {
+  sqlite3_file base;
+  int nSize;
+  int nAlloc;
+  char *zAlloc;
+};
+
+/* Values for fs_file.eType. */
+#define DATABASE_FILE   1
+#define JOURNAL_FILE    2
+
+/*
+** Method declarations for fs_file.
+*/
+static int fsClose(sqlite3_file*);
+static int fsRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
+static int fsWrite(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
+static int fsTruncate(sqlite3_file*, sqlite3_int64 size);
+static int fsSync(sqlite3_file*, int flags);
+static int fsFileSize(sqlite3_file*, sqlite3_int64 *pSize);
+static int fsLock(sqlite3_file*, int);
+static int fsUnlock(sqlite3_file*, int);
+static int fsCheckReservedLock(sqlite3_file*, int *pResOut);
+static int fsFileControl(sqlite3_file*, int op, void *pArg);
+static int fsSectorSize(sqlite3_file*);
+static int fsDeviceCharacteristics(sqlite3_file*);
+
+/*
+** Method declarations for tmp_file.
+*/
+static int tmpClose(sqlite3_file*);
+static int tmpRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
+static int tmpWrite(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
+static int tmpTruncate(sqlite3_file*, sqlite3_int64 size);
+static int tmpSync(sqlite3_file*, int flags);
+static int tmpFileSize(sqlite3_file*, sqlite3_int64 *pSize);
+static int tmpLock(sqlite3_file*, int);
+static int tmpUnlock(sqlite3_file*, int);
+static int tmpCheckReservedLock(sqlite3_file*, int *pResOut);
+static int tmpFileControl(sqlite3_file*, int op, void *pArg);
+static int tmpSectorSize(sqlite3_file*);
+static int tmpDeviceCharacteristics(sqlite3_file*);
+
+/*
+** Method declarations for fs_vfs.
+*/
+static int fsOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
+static int fsDelete(sqlite3_vfs*, const char *zName, int syncDir);
+static int fsAccess(sqlite3_vfs*, const char *zName, int flags, int *);
+static int fsFullPathname(sqlite3_vfs*, const char *zName, int nOut,char *zOut);
+static void *fsDlOpen(sqlite3_vfs*, const char *zFilename);
+static void fsDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
+static void *fsDlSym(sqlite3_vfs*,void*, const char *zSymbol);
+static void fsDlClose(sqlite3_vfs*, void*);
+static int fsRandomness(sqlite3_vfs*, int nByte, char *zOut);
+static int fsSleep(sqlite3_vfs*, int microseconds);
+static int fsCurrentTime(sqlite3_vfs*, double*);
+
+
+typedef struct fs_vfs_t fs_vfs_t;
+struct fs_vfs_t {
+  sqlite3_vfs base;
+  fs_real_file *pFileList;
+  sqlite3_vfs *pParent;
+};
+
+static fs_vfs_t fs_vfs = {
+  {
+    1,                                          /* iVersion */
+    0,                                          /* szOsFile */
+    0,                                          /* mxPathname */
+    0,                                          /* pNext */
+    FS_VFS_NAME,                                /* zName */
+    0,                                          /* pAppData */
+    fsOpen,                                     /* xOpen */
+    fsDelete,                                   /* xDelete */
+    fsAccess,                                   /* xAccess */
+    fsFullPathname,                             /* xFullPathname */
+    fsDlOpen,                                   /* xDlOpen */
+    fsDlError,                                  /* xDlError */
+    fsDlSym,                                    /* xDlSym */
+    fsDlClose,                                  /* xDlClose */
+    fsRandomness,                               /* xRandomness */
+    fsSleep,                                    /* xSleep */
+    fsCurrentTime                               /* xCurrentTime */
+  }, 
+  0,                                            /* pFileList */
+  0                                             /* pParent */
+};
+
+static sqlite3_io_methods fs_io_methods = {
+  1,                            /* iVersion */
+  fsClose,                      /* xClose */
+  fsRead,                       /* xRead */
+  fsWrite,                      /* xWrite */
+  fsTruncate,                   /* xTruncate */
+  fsSync,                       /* xSync */
+  fsFileSize,                   /* xFileSize */
+  fsLock,                       /* xLock */
+  fsUnlock,                     /* xUnlock */
+  fsCheckReservedLock,          /* xCheckReservedLock */
+  fsFileControl,                /* xFileControl */
+  fsSectorSize,                 /* xSectorSize */
+  fsDeviceCharacteristics       /* xDeviceCharacteristics */
+};
+
+
+static sqlite3_io_methods tmp_io_methods = {
+  1,                            /* iVersion */
+  tmpClose,                     /* xClose */
+  tmpRead,                      /* xRead */
+  tmpWrite,                     /* xWrite */
+  tmpTruncate,                  /* xTruncate */
+  tmpSync,                      /* xSync */
+  tmpFileSize,                  /* xFileSize */
+  tmpLock,                      /* xLock */
+  tmpUnlock,                    /* xUnlock */
+  tmpCheckReservedLock,         /* xCheckReservedLock */
+  tmpFileControl,               /* xFileControl */
+  tmpSectorSize,                /* xSectorSize */
+  tmpDeviceCharacteristics      /* xDeviceCharacteristics */
+};
+
+/* Useful macros used in several places */
+#define MIN(x,y) ((x)<(y)?(x):(y))
+#define MAX(x,y) ((x)>(y)?(x):(y))
+
+
+/*
+** Close a tmp-file.
+*/
+static int tmpClose(sqlite3_file *pFile){
+  tmp_file *pTmp = (tmp_file *)pFile;
+  sqlite3_free(pTmp->zAlloc);
+  return SQLITE_OK;
+}
+
+/*
+** Read data from a tmp-file.
+*/
+static int tmpRead(
+  sqlite3_file *pFile, 
+  void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  tmp_file *pTmp = (tmp_file *)pFile;
+  if( (iAmt+iOfst)>pTmp->nSize ){
+    return SQLITE_IOERR_SHORT_READ;
+  }
+  memcpy(zBuf, &pTmp->zAlloc[iOfst], iAmt);
+  return SQLITE_OK;
+}
+
+/*
+** Write data to a tmp-file.
+*/
+static int tmpWrite(
+  sqlite3_file *pFile, 
+  const void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  tmp_file *pTmp = (tmp_file *)pFile;
+  if( (iAmt+iOfst)>pTmp->nAlloc ){
+    int nNew = 2*(iAmt+iOfst+pTmp->nAlloc);
+    char *zNew = sqlite3_realloc(pTmp->zAlloc, nNew);
+    if( !zNew ){
+      return SQLITE_NOMEM;
+    }
+    pTmp->zAlloc = zNew;
+    pTmp->nAlloc = nNew;
+  }
+  memcpy(&pTmp->zAlloc[iOfst], zBuf, iAmt);
+  pTmp->nSize = MAX(pTmp->nSize, iOfst+iAmt);
+  return SQLITE_OK;
+}
+
+/*
+** Truncate a tmp-file.
+*/
+static int tmpTruncate(sqlite3_file *pFile, sqlite_int64 size){
+  tmp_file *pTmp = (tmp_file *)pFile;
+  pTmp->nSize = MIN(pTmp->nSize, size);
+  return SQLITE_OK;
+}
+
+/*
+** Sync a tmp-file.
+*/
+static int tmpSync(sqlite3_file *pFile, int flags){
+  return SQLITE_OK;
+}
+
+/*
+** Return the current file-size of a tmp-file.
+*/
+static int tmpFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
+  tmp_file *pTmp = (tmp_file *)pFile;
+  *pSize = pTmp->nSize;
+  return SQLITE_OK;
+}
+
+/*
+** Lock a tmp-file.
+*/
+static int tmpLock(sqlite3_file *pFile, int eLock){
+  return SQLITE_OK;
+}
+
+/*
+** Unlock a tmp-file.
+*/
+static int tmpUnlock(sqlite3_file *pFile, int eLock){
+  return SQLITE_OK;
+}
+
+/*
+** Check if another file-handle holds a RESERVED lock on a tmp-file.
+*/
+static int tmpCheckReservedLock(sqlite3_file *pFile, int *pResOut){
+  *pResOut = 0;
+  return SQLITE_OK;
+}
+
+/*
+** File control method. For custom operations on a tmp-file.
+*/
+static int tmpFileControl(sqlite3_file *pFile, int op, void *pArg){
+  return SQLITE_OK;
+}
+
+/*
+** Return the sector-size in bytes for a tmp-file.
+*/
+static int tmpSectorSize(sqlite3_file *pFile){
+  return 0;
+}
+
+/*
+** Return the device characteristic flags supported by a tmp-file.
+*/
+static int tmpDeviceCharacteristics(sqlite3_file *pFile){
+  return 0;
+}
+
+/*
+** Close an fs-file.
+*/
+static int fsClose(sqlite3_file *pFile){
+  int rc = SQLITE_OK;
+  fs_file *p = (fs_file *)pFile;
+  fs_real_file *pReal = p->pReal;
+
+  /* Decrement the real_file ref-count. */
+  pReal->nRef--;
+  assert(pReal->nRef>=0);
+
+  /* When the ref-count reaches 0, destroy the structure */
+  if( pReal->nRef==0 ){
+    *pReal->ppThis = pReal->pNext;
+    if( pReal->pNext ){
+      pReal->pNext->ppThis = pReal->ppThis;
+    }
+    rc = pReal->pFile->pMethods->xClose(pReal->pFile);
+    sqlite3_free(pReal);
+  }
+
+  return rc;
+}
+
+/*
+** Read data from an fs-file.
+*/
+static int fsRead(
+  sqlite3_file *pFile, 
+  void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  int rc = SQLITE_OK;
+  fs_file *p = (fs_file *)pFile;
+  fs_real_file *pReal = p->pReal;
+  sqlite3_file *pF = pReal->pFile;
+
+  if( (p->eType==DATABASE_FILE && (iAmt+iOfst)>pReal->nDatabase)
+   || (p->eType==JOURNAL_FILE && (iAmt+iOfst)>pReal->nJournal)
+  ){
+    rc = SQLITE_IOERR_SHORT_READ;
+  }else if( p->eType==DATABASE_FILE ){
+    rc = pF->pMethods->xRead(pF, zBuf, iAmt, iOfst+BLOCKSIZE);
+  }else{
+    /* Journal file. */
+    int iRem = iAmt;
+    int iBuf = 0;
+    int ii = iOfst;
+    while( iRem>0 && rc==SQLITE_OK ){
+      int iRealOff = pReal->nBlob - BLOCKSIZE*((ii/BLOCKSIZE)+1) + ii%BLOCKSIZE;
+      int iRealAmt = MIN(iRem, BLOCKSIZE - (iRealOff%BLOCKSIZE));
+
+      rc = pF->pMethods->xRead(pF, &((char *)zBuf)[iBuf], iRealAmt, iRealOff);
+      ii += iRealAmt;
+      iBuf += iRealAmt;
+      iRem -= iRealAmt;
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Write data to an fs-file.
+*/
+static int fsWrite(
+  sqlite3_file *pFile, 
+  const void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  int rc = SQLITE_OK;
+  fs_file *p = (fs_file *)pFile;
+  fs_real_file *pReal = p->pReal;
+  sqlite3_file *pF = pReal->pFile;
+
+  if( p->eType==DATABASE_FILE ){
+    if( (iAmt+iOfst+BLOCKSIZE)>(pReal->nBlob-pReal->nJournal) ){
+      rc = SQLITE_FULL;
+    }else{
+      rc = pF->pMethods->xWrite(pF, zBuf, iAmt, iOfst+BLOCKSIZE);
+      if( rc==SQLITE_OK ){
+        pReal->nDatabase = MAX(pReal->nDatabase, iAmt+iOfst);
+      }
+    }
+  }else{
+    /* Journal file. */
+    int iRem = iAmt;
+    int iBuf = 0;
+    int ii = iOfst;
+    while( iRem>0 && rc==SQLITE_OK ){
+      int iRealOff = pReal->nBlob - BLOCKSIZE*((ii/BLOCKSIZE)+1) + ii%BLOCKSIZE;
+      int iRealAmt = MIN(iRem, BLOCKSIZE - (iRealOff%BLOCKSIZE));
+
+      if( iRealOff<(pReal->nDatabase+BLOCKSIZE) ){
+        rc = SQLITE_FULL;
+      }else{
+        rc = pF->pMethods->xWrite(pF, &((char *)zBuf)[iBuf], iRealAmt,iRealOff);
+        ii += iRealAmt;
+        iBuf += iRealAmt;
+        iRem -= iRealAmt;
+      }
+    }
+    if( rc==SQLITE_OK ){
+      pReal->nJournal = MAX(pReal->nJournal, iAmt+iOfst);
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Truncate an fs-file.
+*/
+static int fsTruncate(sqlite3_file *pFile, sqlite_int64 size){
+  fs_file *p = (fs_file *)pFile;
+  fs_real_file *pReal = p->pReal;
+  if( p->eType==DATABASE_FILE ){
+    pReal->nDatabase = MIN(pReal->nDatabase, size);
+  }else{
+    pReal->nJournal = MIN(pReal->nJournal, size);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Sync an fs-file.
+*/
+static int fsSync(sqlite3_file *pFile, int flags){
+  fs_file *p = (fs_file *)pFile;
+  fs_real_file *pReal = p->pReal;
+  sqlite3_file *pRealFile = pReal->pFile;
+  int rc = SQLITE_OK;
+
+  if( p->eType==DATABASE_FILE ){
+    unsigned char zSize[4];
+    zSize[0] = (pReal->nDatabase&0xFF000000)>>24;
+    zSize[1] = (pReal->nDatabase&0x00FF0000)>>16;
+    zSize[2] = (pReal->nDatabase&0x0000FF00)>>8;
+    zSize[3] = (pReal->nDatabase&0x000000FF);
+    rc = pRealFile->pMethods->xWrite(pRealFile, zSize, 4, 0);
+  }
+  if( rc==SQLITE_OK ){
+    rc = pRealFile->pMethods->xSync(pRealFile, flags&(~SQLITE_SYNC_DATAONLY));
+  }
+
+  return rc;
+}
+
+/*
+** Return the current file-size of an fs-file.
+*/
+static int fsFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
+  fs_file *p = (fs_file *)pFile;
+  fs_real_file *pReal = p->pReal;
+  if( p->eType==DATABASE_FILE ){
+    *pSize = pReal->nDatabase;
+  }else{
+    *pSize = pReal->nJournal;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Lock an fs-file.
+*/
+static int fsLock(sqlite3_file *pFile, int eLock){
+  return SQLITE_OK;
+}
+
+/*
+** Unlock an fs-file.
+*/
+static int fsUnlock(sqlite3_file *pFile, int eLock){
+  return SQLITE_OK;
+}
+
+/*
+** Check if another file-handle holds a RESERVED lock on an fs-file.
+*/
+static int fsCheckReservedLock(sqlite3_file *pFile, int *pResOut){
+  *pResOut = 0;
+  return SQLITE_OK;
+}
+
+/*
+** File control method. For custom operations on an fs-file.
+*/
+static int fsFileControl(sqlite3_file *pFile, int op, void *pArg){
+  return SQLITE_OK;
+}
+
+/*
+** Return the sector-size in bytes for an fs-file.
+*/
+static int fsSectorSize(sqlite3_file *pFile){
+  return BLOCKSIZE;
+}
+
+/*
+** Return the device characteristic flags supported by an fs-file.
+*/
+static int fsDeviceCharacteristics(sqlite3_file *pFile){
+  return 0;
+}
+
+/*
+** Open an fs file handle.
+*/
+static int fsOpen(
+  sqlite3_vfs *pVfs,
+  const char *zName,
+  sqlite3_file *pFile,
+  int flags,
+  int *pOutFlags
+){
+  fs_vfs_t *pFsVfs = (fs_vfs_t *)pVfs;
+  fs_file *p = (fs_file *)pFile;
+  fs_real_file *pReal = 0;
+  int eType;
+  int nName;
+  int rc = SQLITE_OK;
+
+  if( 0==(flags&(SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_MAIN_JOURNAL)) ){
+    tmp_file *p = (tmp_file *)pFile;
+    memset(p, 0, sizeof(*p));
+    p->base.pMethods = &tmp_io_methods;
+    return SQLITE_OK;
+  }
+
+  eType = ((flags&(SQLITE_OPEN_MAIN_DB))?DATABASE_FILE:JOURNAL_FILE);
+  p->base.pMethods = &fs_io_methods;
+  p->eType = eType;
+
+  assert(strlen("-journal")==8);
+  nName = strlen(zName)-((eType==JOURNAL_FILE)?8:0);
+  pReal=pFsVfs->pFileList; 
+  for(; pReal && strncmp(pReal->zName, zName, nName); pReal=pReal->pNext);
+
+  if( !pReal ){
+    sqlite3_int64 size;
+    sqlite3_file *pRealFile;
+    sqlite3_vfs *pParent = pFsVfs->pParent;
+    assert(eType==DATABASE_FILE);
+
+    pReal = (fs_real_file *)sqlite3_malloc(sizeof(*pReal)+pParent->szOsFile);
+    if( !pReal ){
+      rc = SQLITE_NOMEM;
+      goto open_out;
+    }
+    memset(pReal, 0, sizeof(*pReal)+pParent->szOsFile);
+    pReal->zName = zName;
+    pReal->pFile = (sqlite3_file *)(&pReal[1]);
+
+    rc = pParent->xOpen(pParent, zName, pReal->pFile, flags, pOutFlags);
+    if( rc!=SQLITE_OK ){
+      goto open_out;
+    }
+    pRealFile = pReal->pFile;
+
+    rc = pRealFile->pMethods->xFileSize(pRealFile, &size);
+    if( rc!=SQLITE_OK ){
+      goto open_out;
+    }
+    if( size==0 ){
+      rc = pRealFile->pMethods->xWrite(pRealFile, "\0", 1, BLOBSIZE-1);
+      pReal->nBlob = BLOBSIZE;
+    }else{
+      unsigned char zS[4];
+      pReal->nBlob = size;
+      rc = pRealFile->pMethods->xRead(pRealFile, zS, 4, 0);
+      pReal->nDatabase = (zS[0]<<24)+(zS[1]<<16)+(zS[2]<<8)+zS[3];
+      if( rc==SQLITE_OK ){
+        rc = pRealFile->pMethods->xRead(pRealFile, zS, 4, pReal->nBlob-4);
+        if( zS[0] || zS[1] || zS[2] || zS[3] ){
+          pReal->nJournal = pReal->nBlob;
+        }
+      }
+    }
+
+    if( rc==SQLITE_OK ){
+      pReal->pNext = pFsVfs->pFileList;
+      if( pReal->pNext ){
+        pReal->pNext->ppThis = &pReal->pNext;
+      }
+      pReal->ppThis = &pFsVfs->pFileList;
+      pFsVfs->pFileList = pReal;
+    }
+  }
+
+open_out:
+  if( pReal ){
+    if( rc==SQLITE_OK ){
+      p->pReal = pReal;
+      pReal->nRef++;
+    }else{
+      if( pReal->pFile->pMethods ){
+        pReal->pFile->pMethods->xClose(pReal->pFile);
+      }
+      sqlite3_free(pReal);
+    }
+  }
+  return rc;
+}
+
+/*
+** Delete the file located at zPath. If the dirSync argument is true,
+** ensure the file-system modifications are synced to disk before
+** returning.
+*/
+static int fsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+  int rc = SQLITE_OK;
+  fs_vfs_t *pFsVfs = (fs_vfs_t *)pVfs;
+  fs_real_file *pReal;
+  sqlite3_file *pF;
+  int nName = strlen(zPath) - 8;
+
+  assert(strlen("-journal")==8);
+  assert(strcmp("-journal", &zPath[nName])==0);
+
+  pReal = pFsVfs->pFileList; 
+  for(; pReal && strncmp(pReal->zName, zPath, nName); pReal=pReal->pNext);
+  if( pReal ){
+    pF = pReal->pFile;
+    rc = pF->pMethods->xWrite(pF, "\0\0\0\0", 4, pReal->nBlob-BLOCKSIZE);
+    if( rc==SQLITE_OK ){
+      pReal->nJournal = 0;
+    }
+  }
+  return rc;
+}
+
+/*
+** Test for access permissions. Return true if the requested permission
+** is available, or false otherwise.
+*/
+static int fsAccess(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int flags, 
+  int *pResOut
+){
+  fs_vfs_t *pFsVfs = (fs_vfs_t *)pVfs;
+  fs_real_file *pReal;
+  int isJournal = 0;
+  int nName = strlen(zPath);
+
+  if( flags!=SQLITE_ACCESS_EXISTS ){
+    sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
+    return pParent->xAccess(pParent, zPath, flags, pResOut);
+  }
+
+  assert(strlen("-journal")==8);
+  if( nName>8 && strcmp("-journal", &zPath[nName-8])==0 ){
+    nName -= 8;
+    isJournal = 1;
+  }
+
+  pReal = pFsVfs->pFileList; 
+  for(; pReal && strncmp(pReal->zName, zPath, nName); pReal=pReal->pNext);
+
+  *pResOut = (pReal && (!isJournal || pReal->nJournal>0));
+  return SQLITE_OK;
+}
+
+/*
+** Populate buffer zOut with the full canonical pathname corresponding
+** to the pathname in zPath. zOut is guaranteed to point to a buffer
+** of at least (FS_MAX_PATHNAME+1) bytes.
+*/
+static int fsFullPathname(
+  sqlite3_vfs *pVfs,            /* Pointer to vfs object */
+  const char *zPath,            /* Possibly relative input path */
+  int nOut,                     /* Size of output buffer in bytes */
+  char *zOut                    /* Output buffer */
+){
+  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
+  return pParent->xFullPathname(pParent, zPath, nOut, zOut);
+}
+
+/*
+** Open the dynamic library located at zPath and return a handle.
+*/
+static void *fsDlOpen(sqlite3_vfs *pVfs, const char *zPath){
+  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
+  return pParent->xDlOpen(pParent, zPath);
+}
+
+/*
+** Populate the buffer zErrMsg (size nByte bytes) with a human readable
+** utf-8 string describing the most recent error encountered associated 
+** with dynamic libraries.
+*/
+static void fsDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
+  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
+  pParent->xDlError(pParent, nByte, zErrMsg);
+}
+
+/*
+** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
+*/
+static void *fsDlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol){
+  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
+  return pParent->xDlSym(pParent, pHandle, zSymbol);
+}
+
+/*
+** Close the dynamic library handle pHandle.
+*/
+static void fsDlClose(sqlite3_vfs *pVfs, void *pHandle){
+  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
+  pParent->xDlClose(pParent, pHandle);
+}
+
+/*
+** Populate the buffer pointed to by zBufOut with nByte bytes of 
+** random data.
+*/
+static int fsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
+  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
+  return pParent->xRandomness(pParent, nByte, zBufOut);
+}
+
+/*
+** Sleep for nMicro microseconds. Return the number of microseconds 
+** actually slept.
+*/
+static int fsSleep(sqlite3_vfs *pVfs, int nMicro){
+  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
+  return pParent->xSleep(pParent, nMicro);
+}
+
+/*
+** Return the current time as a Julian Day number in *pTimeOut.
+*/
+static int fsCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
+  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
+  return pParent->xCurrentTime(pParent, pTimeOut);
+}
+
+/*
+** This procedure registers the fs vfs with SQLite. If the argument is
+** true, the fs vfs becomes the new default vfs. It is the only publicly
+** available function in this file.
+*/
+int fs_register(){
+  if( fs_vfs.pParent ) return SQLITE_OK;
+  fs_vfs.pParent = sqlite3_vfs_find(0);
+  fs_vfs.base.mxPathname = fs_vfs.pParent->mxPathname;
+  fs_vfs.base.szOsFile = MAX(sizeof(tmp_file), sizeof(fs_file));
+  return sqlite3_vfs_register(&fs_vfs.base, 0);
+}
+
+#ifdef SQLITE_TEST
+  int SqlitetestOnefile_Init() {return fs_register();}
+#endif
diff --git a/third_party/sqlite/src/test_osinst.c b/third_party/sqlite/src/test_osinst.c
new file mode 100755
index 0000000..a05ef7a
--- /dev/null
+++ b/third_party/sqlite/src/test_osinst.c
@@ -0,0 +1,1069 @@
+/*
+** 2008 April 10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains the implementation of an SQLite vfs wrapper that
+** adds instrumentation to all vfs and file methods. C and Tcl interfaces
+** are provided to control the instrumentation.
+**
+** $Id: test_osinst.c,v 1.18 2008/07/25 13:32:45 drh Exp $
+*/
+
+#ifdef SQLITE_ENABLE_INSTVFS
+/*
+** C interface:
+**
+**   sqlite3_instvfs_create()
+**   sqlite3_instvfs_destroy()
+**   sqlite3_instvfs_configure()
+**
+**   sqlite3_instvfs_reset()
+**   sqlite3_instvfs_get()
+**
+**   sqlite3_instvfs_binarylog
+**   sqlite3_instvfs_binarylog_marker
+**
+** Tcl interface (omitted if SQLITE_TEST is not set):
+** 
+**   sqlite3_instvfs create NAME ?PARENT?
+**
+**       Create and register new vfs called $NAME, which is a wrapper around
+**       the existing vfs $PARENT. If the PARENT argument is omitted, the
+**       new vfs is a wrapper around the current default vfs.
+**
+**   sqlite3_instvfs destroy NAME
+**
+**       Deregister and destroy the vfs named $NAME, which must have been
+**       created by an earlier invocation of [sqlite3_instvfs create].
+**
+**   sqlite3_instvfs configure NAME SCRIPT
+**
+**       Configure the callback script for the vfs $NAME, which much have
+**       been created by an earlier invocation of [sqlite3_instvfs create].
+**       After a callback script has been configured, it is invoked each
+**       time a vfs or file method is called by SQLite. Before invoking
+**       the callback script, five arguments are appended to it:
+**
+**         * The name of the invoked method - i.e. "xRead".
+**
+**         * The time consumed by the method call as measured by 
+**           sqlite3Hwtime() (an integer value)
+**
+**         * A string value with a different meaning for different calls. 
+**           For file methods, the name of the file being operated on. For
+**           other methods it is the filename argument, if any.
+**
+**         * A 32-bit integer value with a call-specific meaning.
+**
+**         * A 64-bit integer value. For xRead() and xWrite() calls this
+**           is the file offset being written to or read from. Unused by
+**           all other calls.
+**
+**   sqlite3_instvfs reset NAME
+**
+**       Zero the internal event counters associated with vfs $NAME, 
+**       which must have been created by an earlier invocation of 
+**       [sqlite3_instvfs create].
+**
+**   sqlite3_instvfs report NAME
+**
+**       Return the values of the internal event counters associated 
+**       with vfs $NAME. The report format is a list with one element
+**       for each method call (xWrite, xRead etc.). Each element is
+**       itself a list with three elements:
+**
+**         * The name of the method call - i.e. "xWrite",
+**         * The total number of calls to the method (an integer).
+**         * The aggregate time consumed by all calls to the method as
+**           measured by sqlite3Hwtime() (an integer).
+*/
+
+#include "sqlite3.h"
+#include <string.h>
+#include <assert.h>
+
+/*
+** Maximum pathname length supported by the inst backend.
+*/
+#define INST_MAX_PATHNAME 512
+
+
+/* File methods */
+/* Vfs methods */
+#define OS_ACCESS            1
+#define OS_CHECKRESERVEDLOCK 2
+#define OS_CLOSE             3
+#define OS_CURRENTTIME       4
+#define OS_DELETE            5
+#define OS_DEVCHAR           6
+#define OS_FILECONTROL       7
+#define OS_FILESIZE          8
+#define OS_FULLPATHNAME      9
+#define OS_LOCK              11
+#define OS_OPEN              12
+#define OS_RANDOMNESS        13
+#define OS_READ              14 
+#define OS_SECTORSIZE        15
+#define OS_SLEEP             16
+#define OS_SYNC              17
+#define OS_TRUNCATE          18
+#define OS_UNLOCK            19
+#define OS_WRITE             20
+
+#define OS_NUMEVENTS         21
+
+#define BINARYLOG_STRING     30
+#define BINARYLOG_MARKER     31
+
+#define BINARYLOG_PREPARE_V2 64
+#define BINARYLOG_STEP       65
+#define BINARYLOG_FINALIZE   66
+
+struct InstVfs {
+  sqlite3_vfs base;
+  sqlite3_vfs *pVfs;
+
+  void *pClient;
+  void (*xDel)(void *);
+  void (*xCall)(void *, int, int, sqlite3_int64, int, const char *, int, int, sqlite3_int64);
+
+  /* Counters */
+  sqlite3_int64 aTime[OS_NUMEVENTS];
+  int aCount[OS_NUMEVENTS];
+
+  int iNextFileId;
+};
+typedef struct InstVfs InstVfs;
+
+#define REALVFS(p) (((InstVfs *)(p))->pVfs)
+
+typedef struct inst_file inst_file;
+struct inst_file {
+  sqlite3_file base;
+  sqlite3_file *pReal;
+  InstVfs *pInstVfs;
+  const char *zName;
+  int iFileId;               /* File id number */
+  int flags;
+};
+
+/*
+** Method declarations for inst_file.
+*/
+static int instClose(sqlite3_file*);
+static int instRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
+static int instWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
+static int instTruncate(sqlite3_file*, sqlite3_int64 size);
+static int instSync(sqlite3_file*, int flags);
+static int instFileSize(sqlite3_file*, sqlite3_int64 *pSize);
+static int instLock(sqlite3_file*, int);
+static int instUnlock(sqlite3_file*, int);
+static int instCheckReservedLock(sqlite3_file*, int *pResOut);
+static int instFileControl(sqlite3_file*, int op, void *pArg);
+static int instSectorSize(sqlite3_file*);
+static int instDeviceCharacteristics(sqlite3_file*);
+
+/*
+** Method declarations for inst_vfs.
+*/
+static int instOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
+static int instDelete(sqlite3_vfs*, const char *zName, int syncDir);
+static int instAccess(sqlite3_vfs*, const char *zName, int flags, int *);
+static int instFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
+static void *instDlOpen(sqlite3_vfs*, const char *zFilename);
+static void instDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
+static void *instDlSym(sqlite3_vfs*,void*, const char *zSymbol);
+static void instDlClose(sqlite3_vfs*, void*);
+static int instRandomness(sqlite3_vfs*, int nByte, char *zOut);
+static int instSleep(sqlite3_vfs*, int microseconds);
+static int instCurrentTime(sqlite3_vfs*, double*);
+
+static void binarylog_blob(sqlite3_vfs *, const char *, int, int); 
+
+static sqlite3_vfs inst_vfs = {
+  1,                      /* iVersion */
+  sizeof(inst_file),      /* szOsFile */
+  INST_MAX_PATHNAME,      /* mxPathname */
+  0,                      /* pNext */
+  0,                      /* zName */
+  0,                      /* pAppData */
+  instOpen,               /* xOpen */
+  instDelete,             /* xDelete */
+  instAccess,             /* xAccess */
+  instFullPathname,       /* xFullPathname */
+  instDlOpen,             /* xDlOpen */
+  instDlError,            /* xDlError */
+  instDlSym,              /* xDlSym */
+  instDlClose,            /* xDlClose */
+  instRandomness,         /* xRandomness */
+  instSleep,              /* xSleep */
+  instCurrentTime         /* xCurrentTime */
+};
+
+static sqlite3_io_methods inst_io_methods = {
+  1,                            /* iVersion */
+  instClose,                      /* xClose */
+  instRead,                       /* xRead */
+  instWrite,                      /* xWrite */
+  instTruncate,                   /* xTruncate */
+  instSync,                       /* xSync */
+  instFileSize,                   /* xFileSize */
+  instLock,                       /* xLock */
+  instUnlock,                     /* xUnlock */
+  instCheckReservedLock,          /* xCheckReservedLock */
+  instFileControl,                /* xFileControl */
+  instSectorSize,                 /* xSectorSize */
+  instDeviceCharacteristics       /* xDeviceCharacteristics */
+};
+
+/* 
+** hwtime.h contains inline assembler code for implementing 
+** high-performance timing routines.
+*/
+#include "hwtime.h"
+
+#define OS_TIME_IO(eEvent, A, B, Call) {     \
+  inst_file *p = (inst_file *)pFile;         \
+  InstVfs *pInstVfs = p->pInstVfs;           \
+  int rc;                                    \
+  sqlite_uint64 t = sqlite3Hwtime();         \
+  rc = Call;                                 \
+  t = sqlite3Hwtime() - t;                   \
+  pInstVfs->aTime[eEvent] += t;              \
+  pInstVfs->aCount[eEvent] += 1;             \
+  if( pInstVfs->xCall ){                     \
+    pInstVfs->xCall(                         \
+      pInstVfs->pClient,eEvent,p->iFileId,t,rc,p->zName,p->flags,A,B  \
+    );                                       \
+  }                                          \
+  return rc;                                 \
+}
+
+#define OS_TIME_VFS(eEvent, Z, flags, A, B, Call) {      \
+  InstVfs *pInstVfs = (InstVfs *)pVfs;   \
+  int rc;                                \
+  sqlite_uint64 t = sqlite3Hwtime();     \
+  rc = Call;                             \
+  t = sqlite3Hwtime() - t;               \
+  pInstVfs->aTime[eEvent] += t;          \
+  pInstVfs->aCount[eEvent] += 1;         \
+  if( pInstVfs->xCall ){                 \
+    pInstVfs->xCall(pInstVfs->pClient,eEvent,0, t, rc, Z, flags, A, B); \
+  }                                      \
+  return rc;                             \
+}
+
+/*
+** Close an inst-file.
+*/
+static int instClose(sqlite3_file *pFile){
+  OS_TIME_IO(OS_CLOSE, 0, 0, 
+    (p->pReal->pMethods ? p->pReal->pMethods->xClose(p->pReal) : SQLITE_OK)
+  );
+}
+
+/*
+** Read data from an inst-file.
+*/
+static int instRead(
+  sqlite3_file *pFile, 
+  void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)(((inst_file *)pFile)->pInstVfs);
+  OS_TIME_IO(OS_READ, iAmt, (binarylog_blob(pVfs, zBuf, iAmt, 1), iOfst), 
+      p->pReal->pMethods->xRead(p->pReal, zBuf, iAmt, iOfst)
+  );
+}
+
+/*
+** Write data to an inst-file.
+*/
+static int instWrite(
+  sqlite3_file *pFile,
+  const void *z,
+  int iAmt,
+  sqlite_int64 iOfst
+){
+  sqlite3_vfs *pVfs = (sqlite3_vfs *)(((inst_file *)pFile)->pInstVfs);
+  binarylog_blob(pVfs, z, iAmt, 1);
+  OS_TIME_IO(OS_WRITE, iAmt, iOfst, 
+      p->pReal->pMethods->xWrite(p->pReal, z, iAmt, iOfst)
+  );
+}
+
+/*
+** Truncate an inst-file.
+*/
+static int instTruncate(sqlite3_file *pFile, sqlite_int64 size){
+  OS_TIME_IO(OS_TRUNCATE, 0, (int)size, 
+    p->pReal->pMethods->xTruncate(p->pReal, size)
+  );
+}
+
+/*
+** Sync an inst-file.
+*/
+static int instSync(sqlite3_file *pFile, int flags){
+  OS_TIME_IO(OS_SYNC, flags, 0, p->pReal->pMethods->xSync(p->pReal, flags));
+}
+
+/*
+** Return the current file-size of an inst-file.
+*/
+static int instFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
+  OS_TIME_IO(OS_FILESIZE, (int)(*pSize), 0, 
+    p->pReal->pMethods->xFileSize(p->pReal, pSize)
+  );
+}
+
+/*
+** Lock an inst-file.
+*/
+static int instLock(sqlite3_file *pFile, int eLock){
+  OS_TIME_IO(OS_LOCK, eLock, 0, p->pReal->pMethods->xLock(p->pReal, eLock));
+}
+
+/*
+** Unlock an inst-file.
+*/
+static int instUnlock(sqlite3_file *pFile, int eLock){
+  OS_TIME_IO(OS_UNLOCK, eLock, 0, p->pReal->pMethods->xUnlock(p->pReal, eLock));
+}
+
+/*
+** Check if another file-handle holds a RESERVED lock on an inst-file.
+*/
+static int instCheckReservedLock(sqlite3_file *pFile, int *pResOut){
+  OS_TIME_IO(OS_CHECKRESERVEDLOCK, 0, 0, 
+      p->pReal->pMethods->xCheckReservedLock(p->pReal, pResOut)
+  );
+}
+
+/*
+** File control method. For custom operations on an inst-file.
+*/
+static int instFileControl(sqlite3_file *pFile, int op, void *pArg){
+  OS_TIME_IO(OS_FILECONTROL, 0, 0, p->pReal->pMethods->xFileControl(p->pReal, op, pArg));
+}
+
+/*
+** Return the sector-size in bytes for an inst-file.
+*/
+static int instSectorSize(sqlite3_file *pFile){
+  OS_TIME_IO(OS_SECTORSIZE, 0, 0, p->pReal->pMethods->xSectorSize(p->pReal));
+}
+
+/*
+** Return the device characteristic flags supported by an inst-file.
+*/
+static int instDeviceCharacteristics(sqlite3_file *pFile){
+  OS_TIME_IO(OS_DEVCHAR, 0, 0, p->pReal->pMethods->xDeviceCharacteristics(p->pReal));
+}
+
+/*
+** Open an inst file handle.
+*/
+static int instOpen(
+  sqlite3_vfs *pVfs,
+  const char *zName,
+  sqlite3_file *pFile,
+  int flags,
+  int *pOutFlags
+){
+  inst_file *p = (inst_file *)pFile;
+  pFile->pMethods = &inst_io_methods;
+  p->pReal = (sqlite3_file *)&p[1];
+  p->pInstVfs = (InstVfs *)pVfs;
+  p->zName = zName;
+  p->flags = flags;
+  p->iFileId = ++p->pInstVfs->iNextFileId;
+
+  binarylog_blob(pVfs, zName, -1, 0);
+  OS_TIME_VFS(OS_OPEN, zName, flags, p->iFileId, 0,
+    REALVFS(pVfs)->xOpen(REALVFS(pVfs), zName, p->pReal, flags, pOutFlags)
+  );
+}
+
+/*
+** Delete the file located at zPath. If the dirSync argument is true,
+** ensure the file-system modifications are synced to disk before
+** returning.
+*/
+static int instDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+  binarylog_blob(pVfs, zPath, -1, 0);
+  OS_TIME_VFS(OS_DELETE, zPath, 0, dirSync, 0,
+    REALVFS(pVfs)->xDelete(REALVFS(pVfs), zPath, dirSync) 
+  );
+}
+
+/*
+** Test for access permissions. Return true if the requested permission
+** is available, or false otherwise.
+*/
+static int instAccess(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int flags, 
+  int *pResOut
+){
+  binarylog_blob(pVfs, zPath, -1, 0);
+  OS_TIME_VFS(OS_ACCESS, zPath, 0, flags, *pResOut, 
+    REALVFS(pVfs)->xAccess(REALVFS(pVfs), zPath, flags, pResOut) 
+  );
+}
+
+/*
+** Populate buffer zOut with the full canonical pathname corresponding
+** to the pathname in zPath. zOut is guaranteed to point to a buffer
+** of at least (INST_MAX_PATHNAME+1) bytes.
+*/
+static int instFullPathname(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int nOut, 
+  char *zOut
+){
+  OS_TIME_VFS( OS_FULLPATHNAME, zPath, 0, 0, 0,
+    REALVFS(pVfs)->xFullPathname(REALVFS(pVfs), zPath, nOut, zOut);
+  );
+}
+
+/*
+** Open the dynamic library located at zPath and return a handle.
+*/
+static void *instDlOpen(sqlite3_vfs *pVfs, const char *zPath){
+  return REALVFS(pVfs)->xDlOpen(REALVFS(pVfs), zPath);
+}
+
+/*
+** Populate the buffer zErrMsg (size nByte bytes) with a human readable
+** utf-8 string describing the most recent error encountered associated 
+** with dynamic libraries.
+*/
+static void instDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
+  REALVFS(pVfs)->xDlError(REALVFS(pVfs), nByte, zErrMsg);
+}
+
+/*
+** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
+*/
+static void *instDlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol){
+  return REALVFS(pVfs)->xDlSym(REALVFS(pVfs), pHandle, zSymbol);
+}
+
+/*
+** Close the dynamic library handle pHandle.
+*/
+static void instDlClose(sqlite3_vfs *pVfs, void *pHandle){
+  REALVFS(pVfs)->xDlClose(REALVFS(pVfs), pHandle);
+}
+
+/*
+** Populate the buffer pointed to by zBufOut with nByte bytes of 
+** random data.
+*/
+static int instRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
+  OS_TIME_VFS( OS_RANDOMNESS, 0, 0, nByte, 0,
+    REALVFS(pVfs)->xRandomness(REALVFS(pVfs), nByte, zBufOut);
+  );
+}
+
+/*
+** Sleep for nMicro microseconds. Return the number of microseconds 
+** actually slept.
+*/
+static int instSleep(sqlite3_vfs *pVfs, int nMicro){
+  OS_TIME_VFS( OS_SLEEP, 0, 0, nMicro, 0, 
+    REALVFS(pVfs)->xSleep(REALVFS(pVfs), nMicro) 
+  );
+}
+
+/*
+** Return the current time as a Julian Day number in *pTimeOut.
+*/
+static int instCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
+  OS_TIME_VFS( OS_CURRENTTIME, 0, 0, 0, 0,
+    REALVFS(pVfs)->xCurrentTime(REALVFS(pVfs), pTimeOut) 
+  );
+}
+
+sqlite3_vfs *sqlite3_instvfs_create(const char *zName, const char *zParent){
+  int nByte;
+  InstVfs *p;
+  sqlite3_vfs *pParent;
+
+  pParent = sqlite3_vfs_find(zParent);
+  if( !pParent ){
+    return 0;
+  }
+
+  nByte = strlen(zName) + 1 + sizeof(InstVfs);
+  p = (InstVfs *)sqlite3_malloc(nByte);
+  if( p ){
+    char *zCopy = (char *)&p[1];
+    memset(p, 0, nByte);
+    memcpy(p, &inst_vfs, sizeof(sqlite3_vfs));
+    p->pVfs = pParent;
+    memcpy(zCopy, zName, strlen(zName));
+    p->base.zName = (const char *)zCopy;
+    p->base.szOsFile += pParent->szOsFile;
+    sqlite3_vfs_register((sqlite3_vfs *)p, 0);
+  }
+
+  return (sqlite3_vfs *)p;
+}
+
+void sqlite3_instvfs_configure(
+  sqlite3_vfs *pVfs,
+  void (*xCall)(
+      void*, 
+      int,                           /* File id */
+      int,                           /* Event code */
+      sqlite3_int64, 
+      int,                           /* Return code */
+      const char*,                   /* File name */
+      int, 
+      int, 
+      sqlite3_int64
+  ),
+  void *pClient,
+  void (*xDel)(void *)
+){
+  InstVfs *p = (InstVfs *)pVfs;
+  assert( pVfs->xOpen==instOpen );
+  if( p->xDel ){
+    p->xDel(p->pClient);
+  }
+  p->xCall = xCall;
+  p->xDel = xDel;
+  p->pClient = pClient;
+}
+
+void sqlite3_instvfs_destroy(sqlite3_vfs *pVfs){
+  if( pVfs ){
+    sqlite3_vfs_unregister(pVfs);
+    sqlite3_instvfs_configure(pVfs, 0, 0, 0);
+    sqlite3_free(pVfs);
+  }
+}
+
+void sqlite3_instvfs_reset(sqlite3_vfs *pVfs){
+  InstVfs *p = (InstVfs *)pVfs;
+  assert( pVfs->xOpen==instOpen );
+  memset(p->aTime, 0, sizeof(sqlite3_int64)*OS_NUMEVENTS);
+  memset(p->aCount, 0, sizeof(int)*OS_NUMEVENTS);
+}
+
+const char *sqlite3_instvfs_name(int eEvent){
+  const char *zEvent = 0;
+
+  switch( eEvent ){
+    case OS_CLOSE:             zEvent = "xClose"; break;
+    case OS_READ:              zEvent = "xRead"; break;
+    case OS_WRITE:             zEvent = "xWrite"; break;
+    case OS_TRUNCATE:          zEvent = "xTruncate"; break;
+    case OS_SYNC:              zEvent = "xSync"; break;
+    case OS_FILESIZE:          zEvent = "xFilesize"; break;
+    case OS_LOCK:              zEvent = "xLock"; break;
+    case OS_UNLOCK:            zEvent = "xUnlock"; break;
+    case OS_CHECKRESERVEDLOCK: zEvent = "xCheckReservedLock"; break;
+    case OS_FILECONTROL:       zEvent = "xFileControl"; break;
+    case OS_SECTORSIZE:        zEvent = "xSectorSize"; break;
+    case OS_DEVCHAR:           zEvent = "xDeviceCharacteristics"; break;
+    case OS_OPEN:              zEvent = "xOpen"; break;
+    case OS_DELETE:            zEvent = "xDelete"; break;
+    case OS_ACCESS:            zEvent = "xAccess"; break;
+    case OS_FULLPATHNAME:      zEvent = "xFullPathname"; break;
+    case OS_RANDOMNESS:        zEvent = "xRandomness"; break;
+    case OS_SLEEP:             zEvent = "xSleep"; break;
+    case OS_CURRENTTIME:       zEvent = "xCurrentTime"; break;
+  }
+
+  return zEvent;
+}
+
+void sqlite3_instvfs_get(
+  sqlite3_vfs *pVfs, 
+  int eEvent, 
+  const char **pzEvent, 
+  sqlite3_int64 *pnClick, 
+  int *pnCall
+){
+  InstVfs *p = (InstVfs *)pVfs;
+  assert( pVfs->xOpen==instOpen );
+  if( eEvent<1 || eEvent>=OS_NUMEVENTS ){
+    *pzEvent = 0;
+    *pnClick = 0;
+    *pnCall = 0;
+    return;
+  }
+
+  *pzEvent = sqlite3_instvfs_name(eEvent);
+  *pnClick = p->aTime[eEvent];
+  *pnCall = p->aCount[eEvent];
+}
+
+#define BINARYLOG_BUFFERSIZE 8192
+
+struct InstVfsBinaryLog {
+  int nBuf;
+  char *zBuf;
+  sqlite3_int64 iOffset;
+  int log_data;
+  sqlite3_file *pOut;
+  char *zOut;                       /* Log file name */
+};
+typedef struct InstVfsBinaryLog InstVfsBinaryLog;
+
+static void put32bits(unsigned char *p, unsigned int v){
+  p[0] = v>>24;
+  p[1] = v>>16;
+  p[2] = v>>8;
+  p[3] = v;
+}
+
+static void binarylog_flush(InstVfsBinaryLog *pLog){
+  sqlite3_file *pFile = pLog->pOut;
+
+#ifdef SQLITE_TEST
+  extern int sqlite3_io_error_pending;
+  extern int sqlite3_io_error_persist;
+  extern int sqlite3_diskfull_pending;
+
+  int pending = sqlite3_io_error_pending;
+  int persist = sqlite3_io_error_persist;
+  int diskfull = sqlite3_diskfull_pending;
+
+  sqlite3_io_error_pending = 0;
+  sqlite3_io_error_persist = 0;
+  sqlite3_diskfull_pending = 0;
+#endif
+
+  pFile->pMethods->xWrite(pFile, pLog->zBuf, pLog->nBuf, pLog->iOffset);
+  pLog->iOffset += pLog->nBuf;
+  pLog->nBuf = 0;
+
+#ifdef SQLITE_TEST
+  sqlite3_io_error_pending = pending;
+  sqlite3_io_error_persist = persist;
+  sqlite3_diskfull_pending = diskfull;
+#endif
+}
+
+static void binarylog_xcall(
+  void *p,
+  int eEvent,
+  int iFileId,
+  sqlite3_int64 nClick,
+  int return_code,
+  const char *zName,
+  int flags,
+  int nByte,
+  sqlite3_int64 iOffset
+){
+  InstVfsBinaryLog *pLog = (InstVfsBinaryLog *)p;
+  unsigned char *zRec;
+  if( (28+pLog->nBuf)>BINARYLOG_BUFFERSIZE ){
+    binarylog_flush(pLog);
+  }
+  zRec = (unsigned char *)&pLog->zBuf[pLog->nBuf];
+  put32bits(&zRec[0], eEvent);
+  put32bits(&zRec[4], (int)iFileId);
+  put32bits(&zRec[8], (int)nClick);
+  put32bits(&zRec[12], return_code);
+  put32bits(&zRec[16], flags);
+  put32bits(&zRec[20], nByte);
+  put32bits(&zRec[24], (int)iOffset);
+  pLog->nBuf += 28;
+}
+
+static void binarylog_xdel(void *p){
+  /* Close the log file and free the memory allocated for the 
+  ** InstVfsBinaryLog structure.
+  */
+  InstVfsBinaryLog *pLog = (InstVfsBinaryLog *)p;
+  sqlite3_file *pFile = pLog->pOut;
+  if( pLog->nBuf ){
+    binarylog_flush(pLog);
+  }
+  pFile->pMethods->xClose(pFile);
+  sqlite3_free(pLog->pOut);
+  sqlite3_free(pLog->zBuf);
+  sqlite3_free(pLog);
+}
+
+static void binarylog_blob(
+  sqlite3_vfs *pVfs,
+  const char *zBlob,
+  int nBlob,
+  int isBinary
+){
+  InstVfsBinaryLog *pLog;
+  InstVfs *pInstVfs = (InstVfs *)pVfs;
+
+  if( pVfs->xOpen!=instOpen || pInstVfs->xCall!=binarylog_xcall ){
+    return;
+  }
+  pLog = (InstVfsBinaryLog *)pInstVfs->pClient;
+  if( zBlob && (!isBinary || pLog->log_data) ){
+    unsigned char *zRec;
+    int nWrite;
+
+    if( nBlob<0 ){
+      nBlob = strlen(zBlob);
+    }
+    nWrite = nBlob + 28;
+  
+    if( (nWrite+pLog->nBuf)>BINARYLOG_BUFFERSIZE ){
+      binarylog_flush(pLog);
+    }
+  
+    zRec = (unsigned char *)&pLog->zBuf[pLog->nBuf];
+    memset(zRec, 0, nWrite);
+    put32bits(&zRec[0], BINARYLOG_STRING);
+    put32bits(&zRec[4], (int)nBlob);
+    put32bits(&zRec[8], (int)isBinary);
+    memcpy(&zRec[28], zBlob, nBlob);
+    pLog->nBuf += nWrite;
+  }
+}
+
+void sqlite3_instvfs_binarylog_call(
+  sqlite3_vfs *pVfs,
+  int eEvent,
+  sqlite3_int64 nClick,
+  int return_code,
+  const char *zString
+){
+  InstVfs *pInstVfs = (InstVfs *)pVfs;
+  InstVfsBinaryLog *pLog = (InstVfsBinaryLog *)pInstVfs->pClient;
+
+  if( zString ){
+    binarylog_blob(pVfs, zString, -1, 0);
+  }
+  binarylog_xcall(pLog, eEvent, 0, nClick, return_code, 0, 0, 0, 0);
+}
+
+void sqlite3_instvfs_binarylog_marker(
+  sqlite3_vfs *pVfs,
+  const char *zMarker
+){
+  InstVfs *pInstVfs = (InstVfs *)pVfs;
+  InstVfsBinaryLog *pLog = (InstVfsBinaryLog *)pInstVfs->pClient;
+  binarylog_blob(pVfs, zMarker, -1, 0);
+  binarylog_xcall(pLog, BINARYLOG_MARKER, 0, 0, 0, 0, 0, 0, 0);
+}
+
+sqlite3_vfs *sqlite3_instvfs_binarylog(
+  const char *zVfs,
+  const char *zParentVfs, 
+  const char *zLog,
+  int log_data
+){
+  InstVfsBinaryLog *p;
+  sqlite3_vfs *pVfs;
+  sqlite3_vfs *pParent;
+  int nByte;
+  int flags;
+  int rc;
+
+  pParent = sqlite3_vfs_find(zParentVfs);
+  if( !pParent ){
+    return 0;
+  }
+
+  nByte = sizeof(InstVfsBinaryLog) + pParent->mxPathname+1;
+  p = (InstVfsBinaryLog *)sqlite3_malloc(nByte);
+  memset(p, 0, nByte);
+  p->zBuf = sqlite3_malloc(BINARYLOG_BUFFERSIZE);
+  p->zOut = (char *)&p[1];
+  p->pOut = (sqlite3_file *)sqlite3_malloc(pParent->szOsFile);
+  p->log_data = log_data;
+  pParent->xFullPathname(pParent, zLog, pParent->mxPathname, p->zOut);
+  flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_MASTER_JOURNAL;
+  pParent->xDelete(pParent, p->zOut, 0);
+  rc = pParent->xOpen(pParent, p->zOut, p->pOut, flags, &flags);
+  if( rc==SQLITE_OK ){
+    memcpy(p->zBuf, "sqlite_ostrace1.....", 20);
+    p->iOffset = 0;
+    p->nBuf = 20;
+  }
+  if( rc ){
+    binarylog_xdel(p);
+    return 0;
+  }
+
+  pVfs = sqlite3_instvfs_create(zVfs, zParentVfs);
+  if( pVfs ){
+    sqlite3_instvfs_configure(pVfs, binarylog_xcall, p, binarylog_xdel);
+  }
+
+  return pVfs;
+}
+#endif /* SQLITE_ENABLE_INSTVFS */
+
+/**************************************************************************
+***************************************************************************
+** Tcl interface starts here.
+*/
+#if SQLITE_TEST
+
+#include <tcl.h>
+
+#ifdef SQLITE_ENABLE_INSTVFS
+struct InstVfsCall {
+  Tcl_Interp *interp;
+  Tcl_Obj *pScript;
+};
+typedef struct InstVfsCall InstVfsCall;
+
+static void test_instvfs_xcall(
+  void *p,
+  int eEvent,
+  int iFileId,
+  sqlite3_int64 nClick,
+  int return_code,
+  const char *zName,
+  int flags,
+  int nByte,
+  sqlite3_int64 iOffset
+){
+  int rc;
+  InstVfsCall *pCall = (InstVfsCall *)p;
+  Tcl_Obj *pObj = Tcl_DuplicateObj( pCall->pScript);
+  const char *zEvent = sqlite3_instvfs_name(eEvent);
+
+  Tcl_IncrRefCount(pObj);
+  Tcl_ListObjAppendElement(0, pObj, Tcl_NewStringObj(zEvent, -1));
+  Tcl_ListObjAppendElement(0, pObj, Tcl_NewWideIntObj(nClick));
+  Tcl_ListObjAppendElement(0, pObj, Tcl_NewStringObj(zName, -1));
+  Tcl_ListObjAppendElement(0, pObj, Tcl_NewIntObj(nByte));
+  Tcl_ListObjAppendElement(0, pObj, Tcl_NewWideIntObj(iOffset));
+
+  rc = Tcl_EvalObjEx(pCall->interp, pObj, TCL_EVAL_GLOBAL|TCL_EVAL_DIRECT);
+  if( rc ){
+    Tcl_BackgroundError(pCall->interp);
+  }
+  Tcl_DecrRefCount(pObj);
+}
+
+static void test_instvfs_xdel(void *p){
+  InstVfsCall *pCall = (InstVfsCall *)p;
+  Tcl_DecrRefCount(pCall->pScript);
+  sqlite3_free(pCall);
+}
+
+static int test_sqlite3_instvfs(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  static const char *IV_strs[] = 
+               { "create",  "destroy",  "reset",  "report", "configure", "binarylog", "marker", 0 };
+  enum IV_enum { IV_CREATE, IV_DESTROY, IV_RESET, IV_REPORT, IV_CONFIGURE, IV_BINARYLOG, IV_MARKER };
+  int iSub;
+
+  if( objc<2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SUB-COMMAND ...");
+  }
+  if( Tcl_GetIndexFromObj(interp, objv[1], IV_strs, "sub-command", 0, &iSub) ){
+    return TCL_ERROR;
+  }
+
+  switch( (enum IV_enum)iSub ){
+    case IV_CREATE: {
+      char *zParent = 0;
+      sqlite3_vfs *p;
+      int isDefault = 0;
+      if( objc>2 && 0==strcmp("-default", Tcl_GetString(objv[2])) ){
+        isDefault = 1;
+      }
+      if( (objc-isDefault)!=4 && (objc-isDefault)!=3 ){
+        Tcl_WrongNumArgs(interp, 2, objv, "?-default? NAME ?PARENT-VFS?");
+        return TCL_ERROR;
+      }
+      if( objc==(4+isDefault) ){
+        zParent = Tcl_GetString(objv[3+isDefault]);
+      }
+      p = sqlite3_instvfs_create(Tcl_GetString(objv[2+isDefault]), zParent);
+      if( !p ){
+        Tcl_AppendResult(interp, "error creating vfs ", 0);
+        return TCL_ERROR;
+      }
+      if( isDefault ){
+        sqlite3_vfs_register(p, 1);
+      }
+      Tcl_SetObjResult(interp, objv[2]);
+      break;
+    }
+    case IV_BINARYLOG: {
+      char *zName = 0;
+      char *zLog = 0;
+      char *zParent = 0;
+      sqlite3_vfs *p;
+      int isDefault = 0;
+      int isLogdata = 0;
+      int argbase = 2;
+
+      for(argbase=2; argbase<(objc-2); argbase++){
+        if( 0==strcmp("-default", Tcl_GetString(objv[argbase])) ){
+          isDefault = 1;
+        }
+        else if( 0==strcmp("-parent", Tcl_GetString(objv[argbase])) ){
+          argbase++;
+          zParent = Tcl_GetString(objv[argbase]);
+        }
+        else if( 0==strcmp("-logdata", Tcl_GetString(objv[argbase])) ){
+          isLogdata = 1;
+        }else{
+          break;
+        }
+      }
+
+      if( (objc-argbase)!=2 ){
+        Tcl_WrongNumArgs(
+            interp, 2, objv, "?-default? ?-parent VFS? ?-logdata? NAME LOGFILE"
+        );
+        return TCL_ERROR;
+      }
+      zName = Tcl_GetString(objv[argbase]);
+      zLog = Tcl_GetString(objv[argbase+1]);
+      p = sqlite3_instvfs_binarylog(zName, zParent, zLog, isLogdata);
+      if( !p ){
+        Tcl_AppendResult(interp, "error creating vfs ", 0);
+        return TCL_ERROR;
+      }
+      if( isDefault ){
+        sqlite3_vfs_register(p, 1);
+      }
+      Tcl_SetObjResult(interp, objv[2]);
+      break;
+    }
+
+    case IV_MARKER: {
+      sqlite3_vfs *p;
+      if( objc!=4 ){
+        Tcl_WrongNumArgs(interp, 2, objv, "VFS MARKER");
+        return TCL_ERROR;
+      }
+      p = sqlite3_vfs_find(Tcl_GetString(objv[2]));
+      if( !p || p->xOpen!=instOpen ){
+        Tcl_AppendResult(interp, "no such vfs: ", Tcl_GetString(objv[2]), 0);
+        return TCL_ERROR;
+      }
+      sqlite3_instvfs_binarylog_marker(p, Tcl_GetString(objv[3]));
+      Tcl_ResetResult(interp);
+      break;
+    }
+
+    case IV_CONFIGURE: {
+      InstVfsCall *pCall;
+
+      sqlite3_vfs *p;
+      if( objc!=4 ){
+        Tcl_WrongNumArgs(interp, 2, objv, "NAME SCRIPT");
+        return TCL_ERROR;
+      }
+      p = sqlite3_vfs_find(Tcl_GetString(objv[2]));
+      if( !p || p->xOpen!=instOpen ){
+        Tcl_AppendResult(interp, "no such vfs: ", Tcl_GetString(objv[2]), 0);
+        return TCL_ERROR;
+      }
+
+      if( strlen(Tcl_GetString(objv[3])) ){
+        pCall = (InstVfsCall *)sqlite3_malloc(sizeof(InstVfsCall));
+        pCall->interp = interp;
+        pCall->pScript = Tcl_DuplicateObj(objv[3]);
+        Tcl_IncrRefCount(pCall->pScript);
+        sqlite3_instvfs_configure(p, 
+            test_instvfs_xcall, (void *)pCall, test_instvfs_xdel
+        );
+      }else{
+        sqlite3_instvfs_configure(p, 0, 0, 0);
+      }
+      break;
+    }
+
+    case IV_REPORT:
+    case IV_DESTROY:
+    case IV_RESET: {
+      sqlite3_vfs *p;
+      if( objc!=3 ){
+        Tcl_WrongNumArgs(interp, 2, objv, "NAME");
+        return TCL_ERROR;
+      }
+      p = sqlite3_vfs_find(Tcl_GetString(objv[2]));
+      if( !p || p->xOpen!=instOpen ){
+        Tcl_AppendResult(interp, "no such vfs: ", Tcl_GetString(objv[2]), 0);
+        return TCL_ERROR;
+      }
+
+      if( ((enum IV_enum)iSub)==IV_DESTROY ){
+        sqlite3_instvfs_destroy(p);
+      }
+      if( ((enum IV_enum)iSub)==IV_RESET ){
+        sqlite3_instvfs_reset(p);
+      }
+      if( ((enum IV_enum)iSub)==IV_REPORT ){
+        int ii;
+        Tcl_Obj *pRet = Tcl_NewObj();
+
+        const char *zName = (char *)1;
+        sqlite3_int64 nClick;
+        int nCall;
+        for(ii=1; zName; ii++){
+          sqlite3_instvfs_get(p, ii, &zName, &nClick, &nCall);
+          if( zName ){
+            Tcl_Obj *pElem = Tcl_NewObj();
+            Tcl_ListObjAppendElement(0, pElem, Tcl_NewStringObj(zName, -1));
+            Tcl_ListObjAppendElement(0, pElem, Tcl_NewIntObj(nCall));
+            Tcl_ListObjAppendElement(0, pElem, Tcl_NewWideIntObj(nClick));
+            Tcl_ListObjAppendElement(0, pRet, pElem);
+          }
+        }
+
+        Tcl_SetObjResult(interp, pRet);
+      }
+
+      break;
+    }
+  }
+
+  return TCL_OK;
+}
+#endif /* SQLITE_ENABLE_INSTVFS */
+
+/* Alternative implementation of sqlite3_instvfs when the real
+** implementation is unavailable. 
+*/
+#ifndef SQLITE_ENABLE_INSTVFS
+static int test_sqlite3_instvfs(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  Tcl_AppendResult(interp, 
+     "not compiled with -DSQLITE_ENABLE_INSTVFS; sqlite3_instvfs is "
+     "unavailable", (char*)0);
+  return TCL_ERROR;
+}
+#endif /* !defined(SQLITE_ENABLE_INSTVFS) */
+
+int SqlitetestOsinst_Init(Tcl_Interp *interp){
+  Tcl_CreateObjCommand(interp, "sqlite3_instvfs", test_sqlite3_instvfs, 0, 0);
+  return TCL_OK;
+}
+
+#endif /* SQLITE_TEST */
diff --git a/third_party/sqlite/src/test_schema.c b/third_party/sqlite/src/test_schema.c
new file mode 100755
index 0000000..51099f5
--- /dev/null
+++ b/third_party/sqlite/src/test_schema.c
@@ -0,0 +1,361 @@
+/*
+** 2006 June 10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing the virtual table interfaces.  This code
+** is not included in the SQLite library.  It is used for automated
+** testing of the SQLite library.
+**
+** $Id: test_schema.c,v 1.15 2008/07/07 14:50:14 drh Exp $
+*/
+
+/* The code in this file defines a sqlite3 virtual-table module that
+** provides a read-only view of the current database schema. There is one
+** row in the schema table for each column in the database schema.
+*/
+#define SCHEMA \
+"CREATE TABLE x("                                                            \
+  "database,"          /* Name of database (i.e. main, temp etc.) */         \
+  "tablename,"         /* Name of table */                                   \
+  "cid,"               /* Column number (from left-to-right, 0 upward) */    \
+  "name,"              /* Column name */                                     \
+  "type,"              /* Specified type (i.e. VARCHAR(32)) */               \
+  "not_null,"          /* Boolean. True if NOT NULL was specified */         \
+  "dflt_value,"        /* Default value for this column */                   \
+  "pk"                 /* True if this column is part of the primary key */  \
+")"
+
+/* If SQLITE_TEST is defined this code is preprocessed for use as part
+** of the sqlite test binary "testfixture". Otherwise it is preprocessed
+** to be compiled into an sqlite dynamic extension.
+*/
+#ifdef SQLITE_TEST
+  #include "sqliteInt.h"
+  #include "tcl.h"
+#else
+  #include "sqlite3ext.h"
+  SQLITE_EXTENSION_INIT1
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+typedef struct schema_vtab schema_vtab;
+typedef struct schema_cursor schema_cursor;
+
+/* A schema table object */
+struct schema_vtab {
+  sqlite3_vtab base;
+  sqlite3 *db;
+};
+
+/* A schema table cursor object */
+struct schema_cursor {
+  sqlite3_vtab_cursor base;
+  sqlite3_stmt *pDbList;
+  sqlite3_stmt *pTableList;
+  sqlite3_stmt *pColumnList;
+  int rowid;
+};
+
+/*
+** None of this works unless we have virtual tables.
+*/
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+/*
+** Table destructor for the schema module.
+*/
+static int schemaDestroy(sqlite3_vtab *pVtab){
+  sqlite3_free(pVtab);
+  return 0;
+}
+
+/*
+** Table constructor for the schema module.
+*/
+static int schemaCreate(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  int rc = SQLITE_NOMEM;
+  schema_vtab *pVtab = sqlite3_malloc(sizeof(schema_vtab));
+  if( pVtab ){
+    memset(pVtab, 0, sizeof(schema_vtab));
+    pVtab->db = db;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    rc = sqlite3_declare_vtab(db, SCHEMA);
+#endif
+  }
+  *ppVtab = (sqlite3_vtab *)pVtab;
+  return rc;
+}
+
+/*
+** Open a new cursor on the schema table.
+*/
+static int schemaOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  int rc = SQLITE_NOMEM;
+  schema_cursor *pCur;
+  pCur = sqlite3_malloc(sizeof(schema_cursor));
+  if( pCur ){
+    memset(pCur, 0, sizeof(schema_cursor));
+    *ppCursor = (sqlite3_vtab_cursor *)pCur;
+    rc = SQLITE_OK;
+  }
+  return rc;
+}
+
+/*
+** Close a schema table cursor.
+*/
+static int schemaClose(sqlite3_vtab_cursor *cur){
+  schema_cursor *pCur = (schema_cursor *)cur;
+  sqlite3_finalize(pCur->pDbList);
+  sqlite3_finalize(pCur->pTableList);
+  sqlite3_finalize(pCur->pColumnList);
+  sqlite3_free(pCur);
+  return SQLITE_OK;
+}
+
+/*
+** Retrieve a column of data.
+*/
+static int schemaColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  schema_cursor *pCur = (schema_cursor *)cur;
+  switch( i ){
+    case 0:
+      sqlite3_result_value(ctx, sqlite3_column_value(pCur->pDbList, 1));
+      break;
+    case 1:
+      sqlite3_result_value(ctx, sqlite3_column_value(pCur->pTableList, 0));
+      break;
+    default:
+      sqlite3_result_value(ctx, sqlite3_column_value(pCur->pColumnList, i-2));
+      break;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Retrieve the current rowid.
+*/
+static int schemaRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  schema_cursor *pCur = (schema_cursor *)cur;
+  *pRowid = pCur->rowid;
+  return SQLITE_OK;
+}
+
+static int finalize(sqlite3_stmt **ppStmt){
+  int rc = sqlite3_finalize(*ppStmt);
+  *ppStmt = 0;
+  return rc;
+}
+
+static int schemaEof(sqlite3_vtab_cursor *cur){
+  schema_cursor *pCur = (schema_cursor *)cur;
+  return (pCur->pDbList ? 0 : 1);
+}
+
+/*
+** Advance the cursor to the next row.
+*/
+static int schemaNext(sqlite3_vtab_cursor *cur){
+  int rc = SQLITE_OK;
+  schema_cursor *pCur = (schema_cursor *)cur;
+  schema_vtab *pVtab = (schema_vtab *)(cur->pVtab);
+  char *zSql = 0;
+
+  while( !pCur->pColumnList || SQLITE_ROW!=sqlite3_step(pCur->pColumnList) ){
+    if( SQLITE_OK!=(rc = finalize(&pCur->pColumnList)) ) goto next_exit;
+
+    while( !pCur->pTableList || SQLITE_ROW!=sqlite3_step(pCur->pTableList) ){
+      if( SQLITE_OK!=(rc = finalize(&pCur->pTableList)) ) goto next_exit;
+
+      assert(pCur->pDbList);
+      while( SQLITE_ROW!=sqlite3_step(pCur->pDbList) ){
+        rc = finalize(&pCur->pDbList);
+        goto next_exit;
+      }
+
+      /* Set zSql to the SQL to pull the list of tables from the 
+      ** sqlite_master (or sqlite_temp_master) table of the database
+      ** identfied by the row pointed to by the SQL statement pCur->pDbList
+      ** (iterating through a "PRAGMA database_list;" statement).
+      */
+      if( sqlite3_column_int(pCur->pDbList, 0)==1 ){
+        zSql = sqlite3_mprintf(
+            "SELECT name FROM sqlite_temp_master WHERE type='table'"
+        );
+      }else{
+        sqlite3_stmt *pDbList = pCur->pDbList;
+        zSql = sqlite3_mprintf(
+            "SELECT name FROM %Q.sqlite_master WHERE type='table'",
+             sqlite3_column_text(pDbList, 1)
+        );
+      }
+      if( !zSql ){
+        rc = SQLITE_NOMEM;
+        goto next_exit;
+      }
+
+      rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pTableList, 0);
+      sqlite3_free(zSql);
+      if( rc!=SQLITE_OK ) goto next_exit;
+    }
+
+    /* Set zSql to the SQL to the table_info pragma for the table currently
+    ** identified by the rows pointed to by statements pCur->pDbList and
+    ** pCur->pTableList.
+    */
+    zSql = sqlite3_mprintf("PRAGMA %Q.table_info(%Q)", 
+        sqlite3_column_text(pCur->pDbList, 1),
+        sqlite3_column_text(pCur->pTableList, 0)
+    );
+
+    if( !zSql ){
+      rc = SQLITE_NOMEM;
+      goto next_exit;
+    }
+    rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pColumnList, 0);
+    sqlite3_free(zSql);
+    if( rc!=SQLITE_OK ) goto next_exit;
+  }
+  pCur->rowid++;
+
+next_exit:
+  /* TODO: Handle rc */
+  return rc;
+}
+
+/*
+** Reset a schema table cursor.
+*/
+static int schemaFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  int rc;
+  schema_vtab *pVtab = (schema_vtab *)(pVtabCursor->pVtab);
+  schema_cursor *pCur = (schema_cursor *)pVtabCursor;
+  pCur->rowid = 0;
+  finalize(&pCur->pTableList);
+  finalize(&pCur->pColumnList);
+  finalize(&pCur->pDbList);
+  rc = sqlite3_prepare(pVtab->db,"PRAGMA database_list", -1, &pCur->pDbList, 0);
+  return (rc==SQLITE_OK ? schemaNext(pVtabCursor) : rc);
+}
+
+/*
+** Analyse the WHERE condition.
+*/
+static int schemaBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  return SQLITE_OK;
+}
+
+/*
+** A virtual table module that merely echos method calls into TCL
+** variables.
+*/
+static sqlite3_module schemaModule = {
+  0,                           /* iVersion */
+  schemaCreate,
+  schemaCreate,
+  schemaBestIndex,
+  schemaDestroy,
+  schemaDestroy,
+  schemaOpen,                  /* xOpen - open a cursor */
+  schemaClose,                 /* xClose - close a cursor */
+  schemaFilter,                /* xFilter - configure scan constraints */
+  schemaNext,                  /* xNext - advance a cursor */
+  schemaEof,                   /* xEof */
+  schemaColumn,                /* xColumn - read data */
+  schemaRowid,                 /* xRowid - read data */
+  0,                           /* xUpdate */
+  0,                           /* xBegin */
+  0,                           /* xSync */
+  0,                           /* xCommit */
+  0,                           /* xRollback */
+  0,                           /* xFindMethod */
+  0,                           /* xRename */
+};
+
+#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */
+
+#ifdef SQLITE_TEST
+
+/*
+** Decode a pointer to an sqlite3 object.
+*/
+extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
+
+/*
+** Register the schema virtual table module.
+*/
+static int register_schema_module(
+  ClientData clientData, /* Not used */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3 *db;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3_create_module(db, "schema", &schemaModule, 0);
+#endif
+  return TCL_OK;
+}
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetestschema_Init(Tcl_Interp *interp){
+  static struct {
+     char *zName;
+     Tcl_ObjCmdProc *xProc;
+     void *clientData;
+  } aObjCmd[] = {
+     { "register_schema_module", register_schema_module, 0 },
+  };
+  int i;
+  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
+    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 
+        aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
+  }
+  return TCL_OK;
+}
+
+#else
+
+/*
+** Extension load function.
+*/
+int sqlite3_extension_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3_create_module(db, "schema", &schemaModule, 0);
+#endif
+  return 0;
+}
+
+#endif
diff --git a/third_party/sqlite/src/test_server.c b/third_party/sqlite/src/test_server.c
new file mode 100755
index 0000000..6862d7c
--- /dev/null
+++ b/third_party/sqlite/src/test_server.c
@@ -0,0 +1,493 @@
+/*
+** 2006 January 07
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** $Id: test_server.c,v 1.8 2008/06/26 10:41:19 danielk1977 Exp $
+**
+** This file contains demonstration code.  Nothing in this file gets compiled
+** or linked into the SQLite library unless you use a non-standard option:
+**
+**      -DSQLITE_SERVER=1
+**
+** The configure script will never generate a Makefile with the option
+** above.  You will need to manually modify the Makefile if you want to
+** include any of the code from this file in your project.  Or, at your
+** option, you may copy and paste the code from this file and
+** thereby avoiding a recompile of SQLite.
+**
+**
+** This source file demonstrates how to use SQLite to create an SQL database 
+** server thread in a multiple-threaded program.  One or more client threads
+** send messages to the server thread and the server thread processes those
+** messages in the order received and returns the results to the client.
+**
+** One might ask:  "Why bother?  Why not just let each thread connect
+** to the database directly?"  There are a several of reasons to
+** prefer the client/server approach.
+**
+**    (1)  Some systems (ex: Redhat9) have broken threading implementations
+**         that prevent SQLite database connections from being used in
+**         a thread different from the one where they were created.  With
+**         the client/server approach, all database connections are created
+**         and used within the server thread.  Client calls to the database
+**         can be made from multiple threads (though not at the same time!)
+**
+**    (2)  Beginning with SQLite version 3.3.0, when two or more 
+**         connections to the same database occur within the same thread,
+**         they can optionally share their database cache.  This reduces
+**         I/O and memory requirements.  Cache shared is controlled using
+**         the sqlite3_enable_shared_cache() API.
+**
+**    (3)  Database connections on a shared cache use table-level locking
+**         instead of file-level locking for improved concurrency.
+**
+**    (4)  Database connections on a shared cache can by optionally
+**         set to READ UNCOMMITTED isolation.  (The default isolation for
+**         SQLite is SERIALIZABLE.)  When this occurs, readers will
+**         never be blocked by a writer and writers will not be
+**         blocked by readers.  There can still only be a single writer
+**         at a time, but multiple readers can simultaneously exist with
+**         that writer.  This is a huge increase in concurrency.
+**
+** To summarize the rational for using a client/server approach: prior
+** to SQLite version 3.3.0 it probably was not worth the trouble.  But
+** with SQLite version 3.3.0 and beyond you can get significant performance
+** and concurrency improvements and memory usage reductions by going
+** client/server.
+**
+** Note:  The extra features of version 3.3.0 described by points (2)
+** through (4) above are only available if you compile without the
+** option -DSQLITE_OMIT_SHARED_CACHE. 
+**
+** Here is how the client/server approach works:  The database server
+** thread is started on this procedure:
+**
+**       void *sqlite3_server(void *NotUsed);
+**
+** The sqlite_server procedure runs as long as the g.serverHalt variable
+** is false.  A mutex is used to make sure no more than one server runs
+** at a time.  The server waits for messages to arrive on a message
+** queue and processes the messages in order.
+**
+** Two convenience routines are provided for starting and stopping the
+** server thread:
+**
+**       void sqlite3_server_start(void);
+**       void sqlite3_server_stop(void);
+**
+** Both of the convenience routines return immediately.  Neither will
+** ever give an error.  If a server is already started or already halted,
+** then the routines are effectively no-ops.
+**
+** Clients use the following interfaces:
+**
+**       sqlite3_client_open
+**       sqlite3_client_prepare
+**       sqlite3_client_step
+**       sqlite3_client_reset
+**       sqlite3_client_finalize
+**       sqlite3_client_close
+**
+** These interfaces work exactly like the standard core SQLite interfaces
+** having the same names without the "_client_" infix.  Many other SQLite
+** interfaces can be used directly without having to send messages to the
+** server as long as SQLITE_ENABLE_MEMORY_MANAGEMENT is not defined.
+** The following interfaces fall into this second category:
+**
+**       sqlite3_bind_*
+**       sqlite3_changes
+**       sqlite3_clear_bindings
+**       sqlite3_column_*
+**       sqlite3_complete
+**       sqlite3_create_collation
+**       sqlite3_create_function
+**       sqlite3_data_count
+**       sqlite3_db_handle
+**       sqlite3_errcode
+**       sqlite3_errmsg
+**       sqlite3_last_insert_rowid
+**       sqlite3_total_changes
+**       sqlite3_transfer_bindings
+**
+** A single SQLite connection (an sqlite3* object) or an SQLite statement
+** (an sqlite3_stmt* object) should only be passed to a single interface
+** function at a time.  The connections and statements can be passed from
+** any thread to any of the functions listed in the second group above as
+** long as the same connection is not in use by two threads at once and
+** as long as SQLITE_ENABLE_MEMORY_MANAGEMENT is not defined.  Additional
+** information about the SQLITE_ENABLE_MEMORY_MANAGEMENT constraint is
+** below.
+**
+** The busy handler for all database connections should remain turned
+** off.  That means that any lock contention will cause the associated
+** sqlite3_client_step() call to return immediately with an SQLITE_BUSY
+** error code.  If a busy handler is enabled and lock contention occurs,
+** then the entire server thread will block.  This will cause not only
+** the requesting client to block but every other database client as
+** well.  It is possible to enhance the code below so that lock
+** contention will cause the message to be placed back on the top of
+** the queue to be tried again later.  But such enhanced processing is
+** not included here, in order to keep the example simple.
+**
+** This example code assumes the use of pthreads.  Pthreads
+** implementations are available for windows.  (See, for example
+** http://sourceware.org/pthreads-win32/announcement.html.)  Or, you
+** can translate the locking and thread synchronization code to use
+** windows primitives easily enough.  The details are left as an
+** exercise to the reader.
+**
+**** Restrictions Associated With SQLITE_ENABLE_MEMORY_MANAGEMENT ****
+**
+** If you compile with SQLITE_ENABLE_MEMORY_MANAGEMENT defined, then
+** SQLite includes code that tracks how much memory is being used by
+** each thread.  These memory counts can become confused if memory
+** is allocated by one thread and then freed by another.  For that
+** reason, when SQLITE_ENABLE_MEMORY_MANAGEMENT is used, all operations
+** that might allocate or free memory should be performanced in the same
+** thread that originally created the database connection.  In that case,
+** many of the operations that are listed above as safe to be performed
+** in separate threads would need to be sent over to the server to be
+** done there.  If SQLITE_ENABLE_MEMORY_MANAGEMENT is defined, then
+** the following functions can be used safely from different threads
+** without messing up the allocation counts:
+**
+**       sqlite3_bind_parameter_name
+**       sqlite3_bind_parameter_index
+**       sqlite3_changes
+**       sqlite3_column_blob
+**       sqlite3_column_count
+**       sqlite3_complete
+**       sqlite3_data_count
+**       sqlite3_db_handle
+**       sqlite3_errcode
+**       sqlite3_errmsg
+**       sqlite3_last_insert_rowid
+**       sqlite3_total_changes
+**
+** The remaining functions are not thread-safe when memory management
+** is enabled.  So one would have to define some new interface routines
+** along the following lines:
+**
+**       sqlite3_client_bind_*
+**       sqlite3_client_clear_bindings
+**       sqlite3_client_column_*
+**       sqlite3_client_create_collation
+**       sqlite3_client_create_function
+**       sqlite3_client_transfer_bindings
+**
+** The example code in this file is intended for use with memory
+** management turned off.  So the implementation of these additional
+** client interfaces is left as an exercise to the reader.
+**
+** It may seem surprising to the reader that the list of safe functions
+** above does not include things like sqlite3_bind_int() or
+** sqlite3_column_int().  But those routines might, in fact, allocate
+** or deallocate memory.  In the case of sqlite3_bind_int(), if the
+** parameter was previously bound to a string that string might need
+** to be deallocated before the new integer value is inserted.  In
+** the case of sqlite3_column_int(), the value of the column might be
+** a UTF-16 string which will need to be converted to UTF-8 then into
+** an integer.
+*/
+
+/* Include this to get the definition of SQLITE_THREADSAFE, in the
+** case that default values are used.
+*/
+#include "sqliteInt.h"
+
+/*
+** Only compile the code in this file on UNIX with a SQLITE_THREADSAFE build
+** and only if the SQLITE_SERVER macro is defined.
+*/
+#if defined(SQLITE_SERVER) && !defined(SQLITE_OMIT_SHARED_CACHE)
+#if defined(SQLITE_OS_UNIX) && OS_UNIX && SQLITE_THREADSAFE
+
+/*
+** We require only pthreads and the public interface of SQLite.
+*/
+#include <pthread.h>
+#include "sqlite3.h"
+
+/*
+** Messages are passed from client to server and back again as 
+** instances of the following structure.
+*/
+typedef struct SqlMessage SqlMessage;
+struct SqlMessage {
+  int op;                      /* Opcode for the message */
+  sqlite3 *pDb;                /* The SQLite connection */
+  sqlite3_stmt *pStmt;         /* A specific statement */
+  int errCode;                 /* Error code returned */
+  const char *zIn;             /* Input filename or SQL statement */
+  int nByte;                   /* Size of the zIn parameter for prepare() */
+  const char *zOut;            /* Tail of the SQL statement */
+  SqlMessage *pNext;           /* Next message in the queue */
+  SqlMessage *pPrev;           /* Previous message in the queue */
+  pthread_mutex_t clientMutex; /* Hold this mutex to access the message */
+  pthread_cond_t clientWakeup; /* Signal to wake up the client */
+};
+
+/*
+** Legal values for SqlMessage.op
+*/
+#define MSG_Open       1  /* sqlite3_open(zIn, &pDb) */
+#define MSG_Prepare    2  /* sqlite3_prepare(pDb, zIn, nByte, &pStmt, &zOut) */
+#define MSG_Step       3  /* sqlite3_step(pStmt) */
+#define MSG_Reset      4  /* sqlite3_reset(pStmt) */
+#define MSG_Finalize   5  /* sqlite3_finalize(pStmt) */
+#define MSG_Close      6  /* sqlite3_close(pDb) */
+#define MSG_Done       7  /* Server has finished with this message */
+
+
+/*
+** State information about the server is stored in a static variable
+** named "g" as follows:
+*/
+static struct ServerState {
+  pthread_mutex_t queueMutex;   /* Hold this mutex to access the msg queue */
+  pthread_mutex_t serverMutex;  /* Held by the server while it is running */
+  pthread_cond_t serverWakeup;  /* Signal this condvar to wake up the server */
+  volatile int serverHalt;      /* Server halts itself when true */
+  SqlMessage *pQueueHead;       /* Head of the message queue */
+  SqlMessage *pQueueTail;       /* Tail of the message queue */
+} g = {
+  PTHREAD_MUTEX_INITIALIZER,
+  PTHREAD_MUTEX_INITIALIZER,
+  PTHREAD_COND_INITIALIZER,
+};
+
+/*
+** Send a message to the server.  Block until we get a reply.
+**
+** The mutex and condition variable in the message are uninitialized
+** when this routine is called.  This routine takes care of 
+** initializing them and destroying them when it has finished.
+*/
+static void sendToServer(SqlMessage *pMsg){
+  /* Initialize the mutex and condition variable on the message
+  */
+  pthread_mutex_init(&pMsg->clientMutex, 0);
+  pthread_cond_init(&pMsg->clientWakeup, 0);
+
+  /* Add the message to the head of the server's message queue.
+  */
+  pthread_mutex_lock(&g.queueMutex);
+  pMsg->pNext = g.pQueueHead;
+  if( g.pQueueHead==0 ){
+    g.pQueueTail = pMsg;
+  }else{
+    g.pQueueHead->pPrev = pMsg;
+  }
+  pMsg->pPrev = 0;
+  g.pQueueHead = pMsg;
+  pthread_mutex_unlock(&g.queueMutex);
+
+  /* Signal the server that the new message has be queued, then
+  ** block waiting for the server to process the message.
+  */
+  pthread_mutex_lock(&pMsg->clientMutex);
+  pthread_cond_signal(&g.serverWakeup);
+  while( pMsg->op!=MSG_Done ){
+    pthread_cond_wait(&pMsg->clientWakeup, &pMsg->clientMutex);
+  }
+  pthread_mutex_unlock(&pMsg->clientMutex);
+
+  /* Destroy the mutex and condition variable of the message.
+  */
+  pthread_mutex_destroy(&pMsg->clientMutex);
+  pthread_cond_destroy(&pMsg->clientWakeup);
+}
+
+/*
+** The following 6 routines are client-side implementations of the
+** core SQLite interfaces:
+**
+**        sqlite3_open
+**        sqlite3_prepare
+**        sqlite3_step
+**        sqlite3_reset
+**        sqlite3_finalize
+**        sqlite3_close
+**
+** Clients should use the following client-side routines instead of 
+** the core routines above.
+**
+**        sqlite3_client_open
+**        sqlite3_client_prepare
+**        sqlite3_client_step
+**        sqlite3_client_reset
+**        sqlite3_client_finalize
+**        sqlite3_client_close
+**
+** Each of these routines creates a message for the desired operation,
+** sends that message to the server, waits for the server to process
+** then message and return a response.
+*/
+int sqlite3_client_open(const char *zDatabaseName, sqlite3 **ppDb){
+  SqlMessage msg;
+  msg.op = MSG_Open;
+  msg.zIn = zDatabaseName;
+  sendToServer(&msg);
+  *ppDb = msg.pDb;
+  return msg.errCode;
+}
+int sqlite3_client_prepare(
+  sqlite3 *pDb,
+  const char *zSql,
+  int nByte,
+  sqlite3_stmt **ppStmt,
+  const char **pzTail
+){
+  SqlMessage msg;
+  msg.op = MSG_Prepare;
+  msg.pDb = pDb;
+  msg.zIn = zSql;
+  msg.nByte = nByte;
+  sendToServer(&msg);
+  *ppStmt = msg.pStmt;
+  if( pzTail ) *pzTail = msg.zOut;
+  return msg.errCode;
+}
+int sqlite3_client_step(sqlite3_stmt *pStmt){
+  SqlMessage msg;
+  msg.op = MSG_Step;
+  msg.pStmt = pStmt;
+  sendToServer(&msg);
+  return msg.errCode;
+}
+int sqlite3_client_reset(sqlite3_stmt *pStmt){
+  SqlMessage msg;
+  msg.op = MSG_Reset;
+  msg.pStmt = pStmt;
+  sendToServer(&msg);
+  return msg.errCode;
+}
+int sqlite3_client_finalize(sqlite3_stmt *pStmt){
+  SqlMessage msg;
+  msg.op = MSG_Finalize;
+  msg.pStmt = pStmt;
+  sendToServer(&msg);
+  return msg.errCode;
+}
+int sqlite3_client_close(sqlite3 *pDb){
+  SqlMessage msg;
+  msg.op = MSG_Close;
+  msg.pDb = pDb;
+  sendToServer(&msg);
+  return msg.errCode;
+}
+
+/*
+** This routine implements the server.  To start the server, first
+** make sure g.serverHalt is false, then create a new detached thread
+** on this procedure.  See the sqlite3_server_start() routine below
+** for an example.  This procedure loops until g.serverHalt becomes
+** true.
+*/
+void *sqlite3_server(void *NotUsed){
+  if( pthread_mutex_trylock(&g.serverMutex) ){
+    return 0;  /* Another server is already running */
+  }
+  sqlite3_enable_shared_cache(1);
+  while( !g.serverHalt ){
+    SqlMessage *pMsg;
+
+    /* Remove the last message from the message queue.
+    */
+    pthread_mutex_lock(&g.queueMutex);
+    while( g.pQueueTail==0 && g.serverHalt==0 ){
+      pthread_cond_wait(&g.serverWakeup, &g.queueMutex);
+    }
+    pMsg = g.pQueueTail;
+    if( pMsg ){
+      if( pMsg->pPrev ){
+        pMsg->pPrev->pNext = 0;
+      }else{
+        g.pQueueHead = 0;
+      }
+      g.pQueueTail = pMsg->pPrev;
+    }
+    pthread_mutex_unlock(&g.queueMutex);
+    if( pMsg==0 ) break;
+
+    /* Process the message just removed
+    */
+    pthread_mutex_lock(&pMsg->clientMutex);
+    switch( pMsg->op ){
+      case MSG_Open: {
+        pMsg->errCode = sqlite3_open(pMsg->zIn, &pMsg->pDb);
+        break;
+      }
+      case MSG_Prepare: {
+        pMsg->errCode = sqlite3_prepare(pMsg->pDb, pMsg->zIn, pMsg->nByte,
+                                        &pMsg->pStmt, &pMsg->zOut);
+        break;
+      }
+      case MSG_Step: {
+        pMsg->errCode = sqlite3_step(pMsg->pStmt);
+        break;
+      }
+      case MSG_Reset: {
+        pMsg->errCode = sqlite3_reset(pMsg->pStmt);
+        break;
+      }
+      case MSG_Finalize: {
+        pMsg->errCode = sqlite3_finalize(pMsg->pStmt);
+        break;
+      }
+      case MSG_Close: {
+        pMsg->errCode = sqlite3_close(pMsg->pDb);
+        break;
+      }
+    }
+
+    /* Signal the client that the message has been processed.
+    */
+    pMsg->op = MSG_Done;
+    pthread_mutex_unlock(&pMsg->clientMutex);
+    pthread_cond_signal(&pMsg->clientWakeup);
+  }
+  sqlite3_thread_cleanup();
+  pthread_mutex_unlock(&g.serverMutex);
+  return 0;
+}
+
+/*
+** Start a server thread if one is not already running.  If there
+** is aleady a server thread running, the new thread will quickly
+** die and this routine is effectively a no-op.
+*/
+void sqlite3_server_start(void){
+  pthread_t x;
+  int rc;
+  g.serverHalt = 0;
+  rc = pthread_create(&x, 0, sqlite3_server, 0);
+  if( rc==0 ){
+    pthread_detach(x);
+  }
+}
+
+/*
+** If a server thread is running, then stop it.  If no server is
+** running, this routine is effectively a no-op.
+**
+** This routine waits until the server has actually stopped before
+** returning.
+*/
+void sqlite3_server_stop(void){
+  g.serverHalt = 1;
+  pthread_cond_broadcast(&g.serverWakeup);
+  pthread_mutex_lock(&g.serverMutex);
+  pthread_mutex_unlock(&g.serverMutex);
+}
+
+#endif /* defined(SQLITE_OS_UNIX) && OS_UNIX && SQLITE_THREADSAFE */
+#endif /* defined(SQLITE_SERVER) */
diff --git a/third_party/sqlite/src/test_tclvar.c b/third_party/sqlite/src/test_tclvar.c
new file mode 100755
index 0000000..6cbec53
--- /dev/null
+++ b/third_party/sqlite/src/test_tclvar.c
@@ -0,0 +1,325 @@
+/*
+** 2006 June 13
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing the virtual table interfaces.  This code
+** is not included in the SQLite library.  It is used for automated
+** testing of the SQLite library.
+**
+** The emphasis of this file is a virtual table that provides
+** access to TCL variables.
+**
+** $Id: test_tclvar.c,v 1.16 2008/07/07 14:50:14 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "tcl.h"
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+typedef struct tclvar_vtab tclvar_vtab;
+typedef struct tclvar_cursor tclvar_cursor;
+
+/* 
+** A tclvar virtual-table object 
+*/
+struct tclvar_vtab {
+  sqlite3_vtab base;
+  Tcl_Interp *interp;
+};
+
+/* A tclvar cursor object */
+struct tclvar_cursor {
+  sqlite3_vtab_cursor base;
+
+  Tcl_Obj *pList1;     /* Result of [info vars ?pattern?] */
+  Tcl_Obj *pList2;     /* Result of [array names [lindex $pList1 $i1]] */
+  int i1;              /* Current item in pList1 */
+  int i2;              /* Current item (if any) in pList2 */
+};
+
+/* Methods for the tclvar module */
+static int tclvarConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  tclvar_vtab *pVtab;
+  static const char zSchema[] = 
+     "CREATE TABLE whatever(name TEXT, arrayname TEXT, value TEXT)";
+  pVtab = sqlite3MallocZero( sizeof(*pVtab) );
+  if( pVtab==0 ) return SQLITE_NOMEM;
+  *ppVtab = &pVtab->base;
+  pVtab->interp = (Tcl_Interp *)pAux;
+  sqlite3_declare_vtab(db, zSchema);
+  return SQLITE_OK;
+}
+/* Note that for this virtual table, the xCreate and xConnect
+** methods are identical. */
+
+static int tclvarDisconnect(sqlite3_vtab *pVtab){
+  sqlite3_free(pVtab);
+  return SQLITE_OK;
+}
+/* The xDisconnect and xDestroy methods are also the same */
+
+/*
+** Open a new tclvar cursor.
+*/
+static int tclvarOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  tclvar_cursor *pCur;
+  pCur = sqlite3MallocZero(sizeof(tclvar_cursor));
+  *ppCursor = &pCur->base;
+  return SQLITE_OK;
+}
+
+/*
+** Close a tclvar cursor.
+*/
+static int tclvarClose(sqlite3_vtab_cursor *cur){
+  tclvar_cursor *pCur = (tclvar_cursor *)cur;
+  if( pCur->pList1 ){
+    Tcl_DecrRefCount(pCur->pList1);
+  }
+  if( pCur->pList2 ){
+    Tcl_DecrRefCount(pCur->pList2);
+  }
+  sqlite3_free(pCur);
+  return SQLITE_OK;
+}
+
+/*
+** Returns 1 if data is ready, or 0 if not.
+*/
+static int next2(Tcl_Interp *interp, tclvar_cursor *pCur, Tcl_Obj *pObj){
+  Tcl_Obj *p;
+
+  if( pObj ){
+    if( !pCur->pList2 ){
+      p = Tcl_NewStringObj("array names", -1);
+      Tcl_IncrRefCount(p);
+      Tcl_ListObjAppendElement(0, p, pObj);
+      Tcl_EvalObjEx(interp, p, TCL_EVAL_GLOBAL);
+      Tcl_DecrRefCount(p);
+      pCur->pList2 = Tcl_GetObjResult(interp);
+      Tcl_IncrRefCount(pCur->pList2);
+      assert( pCur->i2==0 );
+    }else{
+      int n = 0;
+      pCur->i2++;
+      Tcl_ListObjLength(0, pCur->pList2, &n);
+      if( pCur->i2>=n ){
+        Tcl_DecrRefCount(pCur->pList2);
+        pCur->pList2 = 0;
+        pCur->i2 = 0;
+        return 0;
+      }
+    }
+  }
+
+  return 1;
+}
+
+static int tclvarNext(sqlite3_vtab_cursor *cur){
+  Tcl_Obj *pObj;
+  int n = 0;
+  int ok = 0;
+
+  tclvar_cursor *pCur = (tclvar_cursor *)cur;
+  Tcl_Interp *interp = ((tclvar_vtab *)(cur->pVtab))->interp;
+
+  Tcl_ListObjLength(0, pCur->pList1, &n);
+  while( !ok && pCur->i1<n ){
+    Tcl_ListObjIndex(0, pCur->pList1, pCur->i1, &pObj);
+    ok = next2(interp, pCur, pObj);
+    if( !ok ){
+      pCur->i1++;
+    }
+  }
+
+  return 0;
+}
+
+static int tclvarFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  tclvar_cursor *pCur = (tclvar_cursor *)pVtabCursor;
+  Tcl_Interp *interp = ((tclvar_vtab *)(pVtabCursor->pVtab))->interp;
+
+  Tcl_Obj *p = Tcl_NewStringObj("info vars", -1);
+  Tcl_IncrRefCount(p);
+
+  assert( argc==0 || argc==1 );
+  if( argc==1 ){
+    Tcl_Obj *pArg = Tcl_NewStringObj((char*)sqlite3_value_text(argv[0]), -1);
+    Tcl_ListObjAppendElement(0, p, pArg);
+  }
+  Tcl_EvalObjEx(interp, p, TCL_EVAL_GLOBAL);
+  pCur->pList1 = Tcl_GetObjResult(interp);
+  Tcl_IncrRefCount(pCur->pList1);
+  assert( pCur->i1==0 && pCur->i2==0 && pCur->pList2==0 );
+
+  Tcl_DecrRefCount(p);
+  return tclvarNext(pVtabCursor);
+}
+
+static int tclvarColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  Tcl_Obj *p1;
+  Tcl_Obj *p2;
+  const char *z1; 
+  const char *z2 = "";
+  tclvar_cursor *pCur = (tclvar_cursor*)cur;
+  Tcl_Interp *interp = ((tclvar_vtab *)cur->pVtab)->interp;
+
+  Tcl_ListObjIndex(interp, pCur->pList1, pCur->i1, &p1);
+  Tcl_ListObjIndex(interp, pCur->pList2, pCur->i2, &p2);
+  z1 = Tcl_GetString(p1);
+  if( p2 ){
+    z2 = Tcl_GetString(p2);
+  }
+  switch (i) {
+    case 0: {
+      sqlite3_result_text(ctx, z1, -1, SQLITE_TRANSIENT);
+      break;
+    }
+    case 1: {
+      sqlite3_result_text(ctx, z2, -1, SQLITE_TRANSIENT);
+      break;
+    }
+    case 2: {
+      Tcl_Obj *pVal = Tcl_GetVar2Ex(interp, z1, *z2?z2:0, TCL_GLOBAL_ONLY);
+      sqlite3_result_text(ctx, Tcl_GetString(pVal), -1, SQLITE_TRANSIENT);
+      break;
+    }
+  }
+  return SQLITE_OK;
+}
+
+static int tclvarRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  *pRowid = 0;
+  return SQLITE_OK;
+}
+
+static int tclvarEof(sqlite3_vtab_cursor *cur){
+  tclvar_cursor *pCur = (tclvar_cursor*)cur;
+  return (pCur->pList2?0:1);
+}
+
+static int tclvarBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  int ii;
+
+  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
+    struct sqlite3_index_constraint const *pCons = &pIdxInfo->aConstraint[ii];
+    if( pCons->iColumn==0 && pCons->usable
+           && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){
+      struct sqlite3_index_constraint_usage *pUsage;
+      pUsage = &pIdxInfo->aConstraintUsage[ii];
+      pUsage->omit = 0;
+      pUsage->argvIndex = 1;
+      return SQLITE_OK;
+    }
+  }
+
+  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
+    struct sqlite3_index_constraint const *pCons = &pIdxInfo->aConstraint[ii];
+    if( pCons->iColumn==0 && pCons->usable
+           && pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
+      struct sqlite3_index_constraint_usage *pUsage;
+      pUsage = &pIdxInfo->aConstraintUsage[ii];
+      pUsage->omit = 1;
+      pUsage->argvIndex = 1;
+      return SQLITE_OK;
+    }
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** A virtual table module that provides read-only access to a
+** Tcl global variable namespace.
+*/
+static sqlite3_module tclvarModule = {
+  0,                         /* iVersion */
+  tclvarConnect,
+  tclvarConnect,
+  tclvarBestIndex,
+  tclvarDisconnect, 
+  tclvarDisconnect,
+  tclvarOpen,                  /* xOpen - open a cursor */
+  tclvarClose,                 /* xClose - close a cursor */
+  tclvarFilter,                /* xFilter - configure scan constraints */
+  tclvarNext,                  /* xNext - advance a cursor */
+  tclvarEof,                   /* xEof - check for end of scan */
+  tclvarColumn,                /* xColumn - read data */
+  tclvarRowid,                 /* xRowid - read data */
+  0,                           /* xUpdate */
+  0,                           /* xBegin */
+  0,                           /* xSync */
+  0,                           /* xCommit */
+  0,                           /* xRollback */
+  0,                           /* xFindMethod */
+  0,                           /* xRename */
+};
+
+/*
+** Decode a pointer to an sqlite3 object.
+*/
+extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
+
+/*
+** Register the echo virtual table module.
+*/
+static int register_tclvar_module(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3 *db;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3_create_module(db, "tclvar", &tclvarModule, (void *)interp);
+#endif
+  return TCL_OK;
+}
+
+#endif
+
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetesttclvar_Init(Tcl_Interp *interp){
+  static struct {
+     char *zName;
+     Tcl_ObjCmdProc *xProc;
+     void *clientData;
+  } aObjCmd[] = {
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+     { "register_tclvar_module",   register_tclvar_module, 0 },
+#endif
+  };
+  int i;
+  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
+    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 
+        aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
+  }
+  return TCL_OK;
+}
diff --git a/third_party/sqlite/src/test_thread.c b/third_party/sqlite/src/test_thread.c
new file mode 100755
index 0000000..d74470e
--- /dev/null
+++ b/third_party/sqlite/src/test_thread.c
@@ -0,0 +1,332 @@
+/*
+** 2007 September 9
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains the implementation of some Tcl commands used to
+** test that sqlite3 database handles may be concurrently accessed by 
+** multiple threads. Right now this only works on unix.
+**
+** $Id: test_thread.c,v 1.6 2007/12/13 21:54:11 drh Exp $
+*/
+
+#include "sqliteInt.h"
+#include <tcl.h>
+
+#if SQLITE_THREADSAFE && defined(TCL_THREADS)
+
+#include <errno.h>
+#include <unistd.h>
+
+/*
+** One of these is allocated for each thread created by [sqlthread spawn].
+*/
+typedef struct SqlThread SqlThread;
+struct SqlThread {
+  Tcl_ThreadId parent;     /* Thread id of parent thread */
+  Tcl_Interp *interp;      /* Parent interpreter */
+  char *zScript;           /* The script to execute. */
+  char *zVarname;          /* Varname in parent script */
+};
+
+/*
+** A custom Tcl_Event type used by this module. When the event is
+** handled, script zScript is evaluated in interpreter interp. If
+** the evaluation throws an exception (returns TCL_ERROR), then the
+** error is handled by Tcl_BackgroundError(). If no error occurs,
+** the result is simply discarded.
+*/
+typedef struct EvalEvent EvalEvent;
+struct EvalEvent {
+  Tcl_Event base;          /* Base class of type Tcl_Event */
+  char *zScript;           /* The script to execute. */
+  Tcl_Interp *interp;      /* The interpreter to execute it in. */
+};
+
+static Tcl_ObjCmdProc sqlthread_proc;
+int Sqlitetest1_Init(Tcl_Interp *);
+
+/*
+** Handler for events of type EvalEvent.
+*/
+static int tclScriptEvent(Tcl_Event *evPtr, int flags){
+  int rc;
+  EvalEvent *p = (EvalEvent *)evPtr;
+  rc = Tcl_Eval(p->interp, p->zScript);
+  if( rc!=TCL_OK ){
+    Tcl_BackgroundError(p->interp);
+  }
+  return 1;
+}
+
+/*
+** Register an EvalEvent to evaluate the script pScript in the
+** parent interpreter/thread of SqlThread p.
+*/
+static void postToParent(SqlThread *p, Tcl_Obj *pScript){
+  EvalEvent *pEvent;
+  char *zMsg;
+  int nMsg;
+
+  zMsg = Tcl_GetStringFromObj(pScript, &nMsg); 
+  pEvent = (EvalEvent *)ckalloc(sizeof(EvalEvent)+nMsg+1);
+  pEvent->base.nextPtr = 0;
+  pEvent->base.proc = tclScriptEvent;
+  pEvent->zScript = (char *)&pEvent[1];
+  memcpy(pEvent->zScript, zMsg, nMsg+1);
+  pEvent->interp = p->interp;
+
+  Tcl_ThreadQueueEvent(p->parent, (Tcl_Event *)pEvent, TCL_QUEUE_TAIL);
+  Tcl_ThreadAlert(p->parent);
+}
+
+/*
+** The main function for threads created with [sqlthread spawn].
+*/
+static Tcl_ThreadCreateType tclScriptThread(ClientData pSqlThread){
+  Tcl_Interp *interp;
+  Tcl_Obj *pRes;
+  Tcl_Obj *pList;
+  int rc;
+
+  SqlThread *p = (SqlThread *)pSqlThread;
+
+  interp = Tcl_CreateInterp();
+  Tcl_CreateObjCommand(interp, "sqlthread", sqlthread_proc, pSqlThread, 0);
+  Sqlitetest1_Init(interp);
+
+  rc = Tcl_Eval(interp, p->zScript);
+  pRes = Tcl_GetObjResult(interp);
+  pList = Tcl_NewObj();
+  Tcl_IncrRefCount(pList);
+  Tcl_IncrRefCount(pRes);
+
+  if( rc!=TCL_OK ){
+    Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj("error", -1));
+    Tcl_ListObjAppendElement(interp, pList, pRes);
+    postToParent(p, pList);
+    Tcl_DecrRefCount(pList);
+    pList = Tcl_NewObj();
+  }
+
+  Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj("set", -1));
+  Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj(p->zVarname, -1));
+  Tcl_ListObjAppendElement(interp, pList, pRes);
+  postToParent(p, pList);
+
+  ckfree((void *)p);
+  Tcl_DecrRefCount(pList);
+  Tcl_DecrRefCount(pRes);
+  Tcl_DeleteInterp(interp);
+  return;
+}
+
+/*
+** sqlthread spawn VARNAME SCRIPT
+**
+**     Spawn a new thread with its own Tcl interpreter and run the
+**     specified SCRIPT(s) in it. The thread terminates after running
+**     the script. The result of the script is stored in the variable
+**     VARNAME.
+**
+**     The caller can wait for the script to terminate using [vwait VARNAME].
+*/
+static int sqlthread_spawn(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  Tcl_ThreadId x;
+  SqlThread *pNew;
+  int rc;
+
+  int nVarname; char *zVarname;
+  int nScript; char *zScript;
+
+  /* Parameters for thread creation */
+  const int nStack = TCL_THREAD_STACK_DEFAULT;
+  const int flags = TCL_THREAD_NOFLAGS;
+
+  assert(objc==4);
+
+  zVarname = Tcl_GetStringFromObj(objv[2], &nVarname);
+  zScript = Tcl_GetStringFromObj(objv[3], &nScript);
+
+  pNew = (SqlThread *)ckalloc(sizeof(SqlThread)+nVarname+nScript+2);
+  pNew->zVarname = (char *)&pNew[1];
+  pNew->zScript = (char *)&pNew->zVarname[nVarname+1];
+  memcpy(pNew->zVarname, zVarname, nVarname+1);
+  memcpy(pNew->zScript, zScript, nScript+1);
+  pNew->parent = Tcl_GetCurrentThread();
+  pNew->interp = interp;
+
+  rc = Tcl_CreateThread(&x, tclScriptThread, (void *)pNew, nStack, flags);
+  if( rc!=TCL_OK ){
+    Tcl_AppendResult(interp, "Error in Tcl_CreateThread()", 0);
+    sqlite3_free(pNew);
+    return TCL_ERROR;
+  }
+
+  return TCL_OK;
+}
+
+/*
+** sqlthread parent SCRIPT
+**
+**     This can be called by spawned threads only. It sends the specified
+**     script back to the parent thread for execution. The result of
+**     evaluating the SCRIPT is returned. The parent thread must enter
+**     the event loop for this to work - otherwise the caller will
+**     block indefinitely.
+**
+**     NOTE: At the moment, this doesn't work. FIXME.
+*/
+static int sqlthread_parent(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  EvalEvent *pEvent;
+  char *zMsg;
+  int nMsg;
+  SqlThread *p = (SqlThread *)clientData;
+
+  assert(objc==3);
+  if( p==0 ){
+    Tcl_AppendResult(interp, "no parent thread", 0);
+    return TCL_ERROR;
+  }
+
+  zMsg = Tcl_GetStringFromObj(objv[2], &nMsg);
+  pEvent = (EvalEvent *)ckalloc(sizeof(EvalEvent)+nMsg+1);
+  pEvent->base.nextPtr = 0;
+  pEvent->base.proc = tclScriptEvent;
+  pEvent->zScript = (char *)&pEvent[1];
+  memcpy(pEvent->zScript, zMsg, nMsg+1);
+  pEvent->interp = p->interp;
+  Tcl_ThreadQueueEvent(p->parent, (Tcl_Event *)pEvent, TCL_QUEUE_TAIL);
+  Tcl_ThreadAlert(p->parent);
+
+  return TCL_OK;
+}
+
+static int xBusy(void *pArg, int nBusy){
+  sqlite3_sleep(50);
+  return 1;             /* Try again... */
+}
+
+/*
+** sqlthread open
+**
+**     Open a database handle and return the string representation of
+**     the pointer value.
+*/
+static int sqlthread_open(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int sqlite3TestMakePointerStr(Tcl_Interp *interp, char *zPtr, void *p);
+
+  const char *zFilename;
+  sqlite3 *db;
+  int rc;
+  char zBuf[100];
+  extern void Md5_Register(sqlite3*);
+
+  zFilename = Tcl_GetString(objv[2]);
+  rc = sqlite3_open(zFilename, &db);
+  Md5_Register(db);
+  sqlite3_busy_handler(db, xBusy, 0);
+  
+  if( sqlite3TestMakePointerStr(interp, zBuf, db) ) return TCL_ERROR;
+  Tcl_AppendResult(interp, zBuf, 0);
+
+  return TCL_OK;
+}
+
+
+/*
+** sqlthread open
+**
+**     Return the current thread-id (Tcl_GetCurrentThread()) cast to
+**     an integer.
+*/
+static int sqlthread_id(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  Tcl_ThreadId id = Tcl_GetCurrentThread();
+  Tcl_SetObjResult(interp, Tcl_NewIntObj((int)id));
+  return TCL_OK;
+}
+
+
+/*
+** Dispatch routine for the sub-commands of [sqlthread].
+*/
+static int sqlthread_proc(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  struct SubCommand {
+    char *zName;
+    Tcl_ObjCmdProc *xProc;
+    int nArg;
+    char *zUsage;
+  } aSub[] = {
+    {"parent", sqlthread_parent, 1, "SCRIPT"},
+    {"spawn",  sqlthread_spawn,  2, "VARNAME SCRIPT"},
+    {"open",   sqlthread_open,   1, "DBNAME"},
+    {"id",     sqlthread_id,     0, ""},
+    {0, 0, 0}
+  };
+  struct SubCommand *pSub;
+  int rc;
+  int iIndex;
+
+  if( objc<2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SUB-COMMAND");
+    return TCL_ERROR;
+  }
+
+  rc = Tcl_GetIndexFromObjStruct(
+      interp, objv[1], aSub, sizeof(aSub[0]), "sub-command", 0, &iIndex
+  );
+  if( rc!=TCL_OK ) return rc;
+  pSub = &aSub[iIndex];
+
+  if( objc!=(pSub->nArg+2) ){
+    Tcl_WrongNumArgs(interp, 2, objv, pSub->zUsage);
+    return TCL_ERROR;
+  }
+
+  return pSub->xProc(clientData, interp, objc, objv);
+}
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int SqlitetestThread_Init(Tcl_Interp *interp){
+  Tcl_CreateObjCommand(interp, "sqlthread", sqlthread_proc, 0, 0);
+  return TCL_OK;
+}
+#else
+int SqlitetestThread_Init(Tcl_Interp *interp){
+  return TCL_OK;
+}
+#endif
diff --git a/third_party/sqlite/src/tokenize.c b/third_party/sqlite/src/tokenize.c
new file mode 100755
index 0000000..bea8d5e
--- /dev/null
+++ b/third_party/sqlite/src/tokenize.c
@@ -0,0 +1,508 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** An tokenizer for SQL
+**
+** This file contains C code that splits an SQL input string up into
+** individual tokens and sends those tokens one-by-one over to the
+** parser for analysis.
+**
+** $Id: tokenize.c,v 1.148 2008/07/28 19:34:54 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+#include <stdlib.h>
+
+/*
+** The charMap() macro maps alphabetic characters into their
+** lower-case ASCII equivalent.  On ASCII machines, this is just
+** an upper-to-lower case map.  On EBCDIC machines we also need
+** to adjust the encoding.  Only alphabetic characters and underscores
+** need to be translated.
+*/
+#ifdef SQLITE_ASCII
+# define charMap(X) sqlite3UpperToLower[(unsigned char)X]
+#endif
+#ifdef SQLITE_EBCDIC
+# define charMap(X) ebcdicToAscii[(unsigned char)X]
+const unsigned char ebcdicToAscii[] = {
+/* 0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 0x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 1x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 2x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 3x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 4x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 5x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 95,  0,  0,  /* 6x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 7x */
+   0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* 8x */
+   0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* 9x */
+   0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ax */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Bx */
+   0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* Cx */
+   0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* Dx */
+   0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ex */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Fx */
+};
+#endif
+
+/*
+** The sqlite3KeywordCode function looks up an identifier to determine if
+** it is a keyword.  If it is a keyword, the token code of that keyword is 
+** returned.  If the input is not a keyword, TK_ID is returned.
+**
+** The implementation of this routine was generated by a program,
+** mkkeywordhash.h, located in the tool subdirectory of the distribution.
+** The output of the mkkeywordhash.c program is written into a file
+** named keywordhash.h and then included into this source file by
+** the #include below.
+*/
+#include "keywordhash.h"
+
+
+/*
+** If X is a character that can be used in an identifier then
+** IdChar(X) will be true.  Otherwise it is false.
+**
+** For ASCII, any character with the high-order bit set is
+** allowed in an identifier.  For 7-bit characters, 
+** sqlite3IsIdChar[X] must be 1.
+**
+** For EBCDIC, the rules are more complex but have the same
+** end result.
+**
+** Ticket #1066.  the SQL standard does not allow '$' in the
+** middle of identfiers.  But many SQL implementations do. 
+** SQLite will allow '$' in identifiers for compatibility.
+** But the feature is undocumented.
+*/
+#ifdef SQLITE_ASCII
+const char sqlite3IsAsciiIdChar[] = {
+/* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
+    0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 2x */
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  /* 3x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /* 4x */
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1,  /* 5x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /* 6x */
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,  /* 7x */
+};
+#define IdChar(C)  (((c=C)&0x80)!=0 || (c>0x1f && sqlite3IsAsciiIdChar[c-0x20]))
+#endif
+#ifdef SQLITE_EBCDIC
+const char sqlite3IsEbcdicIdChar[] = {
+/* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
+    0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  /* 4x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0,  /* 5x */
+    0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0,  /* 6x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,  /* 7x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0,  /* 8x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0,  /* 9x */
+    1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0,  /* Ax */
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* Bx */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Cx */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Dx */
+    0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Ex */
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0,  /* Fx */
+};
+#define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
+#endif
+
+
+/*
+** Return the length of the token that begins at z[0]. 
+** Store the token type in *tokenType before returning.
+*/
+int sqlite3GetToken(const unsigned char *z, int *tokenType){
+  int i, c;
+  switch( *z ){
+    case ' ': case '\t': case '\n': case '\f': case '\r': {
+      for(i=1; isspace(z[i]); i++){}
+      *tokenType = TK_SPACE;
+      return i;
+    }
+    case '-': {
+      if( z[1]=='-' ){
+        for(i=2; (c=z[i])!=0 && c!='\n'; i++){}
+        *tokenType = TK_COMMENT;
+        return i;
+      }
+      *tokenType = TK_MINUS;
+      return 1;
+    }
+    case '(': {
+      *tokenType = TK_LP;
+      return 1;
+    }
+    case ')': {
+      *tokenType = TK_RP;
+      return 1;
+    }
+    case ';': {
+      *tokenType = TK_SEMI;
+      return 1;
+    }
+    case '+': {
+      *tokenType = TK_PLUS;
+      return 1;
+    }
+    case '*': {
+      *tokenType = TK_STAR;
+      return 1;
+    }
+    case '/': {
+      if( z[1]!='*' || z[2]==0 ){
+        *tokenType = TK_SLASH;
+        return 1;
+      }
+      for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}
+      if( c ) i++;
+      *tokenType = TK_COMMENT;
+      return i;
+    }
+    case '%': {
+      *tokenType = TK_REM;
+      return 1;
+    }
+    case '=': {
+      *tokenType = TK_EQ;
+      return 1 + (z[1]=='=');
+    }
+    case '<': {
+      if( (c=z[1])=='=' ){
+        *tokenType = TK_LE;
+        return 2;
+      }else if( c=='>' ){
+        *tokenType = TK_NE;
+        return 2;
+      }else if( c=='<' ){
+        *tokenType = TK_LSHIFT;
+        return 2;
+      }else{
+        *tokenType = TK_LT;
+        return 1;
+      }
+    }
+    case '>': {
+      if( (c=z[1])=='=' ){
+        *tokenType = TK_GE;
+        return 2;
+      }else if( c=='>' ){
+        *tokenType = TK_RSHIFT;
+        return 2;
+      }else{
+        *tokenType = TK_GT;
+        return 1;
+      }
+    }
+    case '!': {
+      if( z[1]!='=' ){
+        *tokenType = TK_ILLEGAL;
+        return 2;
+      }else{
+        *tokenType = TK_NE;
+        return 2;
+      }
+    }
+    case '|': {
+      if( z[1]!='|' ){
+        *tokenType = TK_BITOR;
+        return 1;
+      }else{
+        *tokenType = TK_CONCAT;
+        return 2;
+      }
+    }
+    case ',': {
+      *tokenType = TK_COMMA;
+      return 1;
+    }
+    case '&': {
+      *tokenType = TK_BITAND;
+      return 1;
+    }
+    case '~': {
+      *tokenType = TK_BITNOT;
+      return 1;
+    }
+    case '`':
+    case '\'':
+    case '"': {
+      int delim = z[0];
+      for(i=1; (c=z[i])!=0; i++){
+        if( c==delim ){
+          if( z[i+1]==delim ){
+            i++;
+          }else{
+            break;
+          }
+        }
+      }
+      if( c ){
+        *tokenType = TK_STRING;
+        return i+1;
+      }else{
+        *tokenType = TK_ILLEGAL;
+        return i;
+      }
+    }
+    case '.': {
+#ifndef SQLITE_OMIT_FLOATING_POINT
+      if( !isdigit(z[1]) )
+#endif
+      {
+        *tokenType = TK_DOT;
+        return 1;
+      }
+      /* If the next character is a digit, this is a floating point
+      ** number that begins with ".".  Fall thru into the next case */
+    }
+    case '0': case '1': case '2': case '3': case '4':
+    case '5': case '6': case '7': case '8': case '9': {
+      *tokenType = TK_INTEGER;
+      for(i=0; isdigit(z[i]); i++){}
+#ifndef SQLITE_OMIT_FLOATING_POINT
+      if( z[i]=='.' ){
+        i++;
+        while( isdigit(z[i]) ){ i++; }
+        *tokenType = TK_FLOAT;
+      }
+      if( (z[i]=='e' || z[i]=='E') &&
+           ( isdigit(z[i+1]) 
+            || ((z[i+1]=='+' || z[i+1]=='-') && isdigit(z[i+2]))
+           )
+      ){
+        i += 2;
+        while( isdigit(z[i]) ){ i++; }
+        *tokenType = TK_FLOAT;
+      }
+#endif
+      while( IdChar(z[i]) ){
+        *tokenType = TK_ILLEGAL;
+        i++;
+      }
+      return i;
+    }
+    case '[': {
+      for(i=1, c=z[0]; c!=']' && (c=z[i])!=0; i++){}
+      *tokenType = c==']' ? TK_ID : TK_ILLEGAL;
+      return i;
+    }
+    case '?': {
+      *tokenType = TK_VARIABLE;
+      for(i=1; isdigit(z[i]); i++){}
+      return i;
+    }
+    case '#': {
+      for(i=1; isdigit(z[i]); i++){}
+      if( i>1 ){
+        /* Parameters of the form #NNN (where NNN is a number) are used
+        ** internally by sqlite3NestedParse.  */
+        *tokenType = TK_REGISTER;
+        return i;
+      }
+      /* Fall through into the next case if the '#' is not followed by
+      ** a digit. Try to match #AAAA where AAAA is a parameter name. */
+    }
+#ifndef SQLITE_OMIT_TCL_VARIABLE
+    case '$':
+#endif
+    case '@':  /* For compatibility with MS SQL Server */
+    case ':': {
+      int n = 0;
+      *tokenType = TK_VARIABLE;
+      for(i=1; (c=z[i])!=0; i++){
+        if( IdChar(c) ){
+          n++;
+#ifndef SQLITE_OMIT_TCL_VARIABLE
+        }else if( c=='(' && n>0 ){
+          do{
+            i++;
+          }while( (c=z[i])!=0 && !isspace(c) && c!=')' );
+          if( c==')' ){
+            i++;
+          }else{
+            *tokenType = TK_ILLEGAL;
+          }
+          break;
+        }else if( c==':' && z[i+1]==':' ){
+          i++;
+#endif
+        }else{
+          break;
+        }
+      }
+      if( n==0 ) *tokenType = TK_ILLEGAL;
+      return i;
+    }
+#ifndef SQLITE_OMIT_BLOB_LITERAL
+    case 'x': case 'X': {
+      if( z[1]=='\'' ){
+        *tokenType = TK_BLOB;
+        for(i=2; (c=z[i])!=0 && c!='\''; i++){
+          if( !isxdigit(c) ){
+            *tokenType = TK_ILLEGAL;
+          }
+        }
+        if( i%2 || !c ) *tokenType = TK_ILLEGAL;
+        if( c ) i++;
+        return i;
+      }
+      /* Otherwise fall through to the next case */
+    }
+#endif
+    default: {
+      if( !IdChar(*z) ){
+        break;
+      }
+      for(i=1; IdChar(z[i]); i++){}
+      *tokenType = keywordCode((char*)z, i);
+      return i;
+    }
+  }
+  *tokenType = TK_ILLEGAL;
+  return 1;
+}
+
+/*
+** Run the parser on the given SQL string.  The parser structure is
+** passed in.  An SQLITE_ status code is returned.  If an error occurs
+** then an and attempt is made to write an error message into 
+** memory obtained from sqlite3_malloc() and to make *pzErrMsg point to that
+** error message.
+*/
+int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
+  int nErr = 0;
+  int i;
+  void *pEngine;
+  int tokenType;
+  int lastTokenParsed = -1;
+  sqlite3 *db = pParse->db;
+  int mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
+
+  if( db->activeVdbeCnt==0 ){
+    db->u1.isInterrupted = 0;
+  }
+  pParse->rc = SQLITE_OK;
+  pParse->zTail = pParse->zSql = zSql;
+  i = 0;
+  assert( pzErrMsg!=0 );
+  pEngine = sqlite3ParserAlloc((void*(*)(size_t))sqlite3Malloc);
+  if( pEngine==0 ){
+    db->mallocFailed = 1;
+    return SQLITE_NOMEM;
+  }
+  assert( pParse->sLastToken.dyn==0 );
+  assert( pParse->pNewTable==0 );
+  assert( pParse->pNewTrigger==0 );
+  assert( pParse->nVar==0 );
+  assert( pParse->nVarExpr==0 );
+  assert( pParse->nVarExprAlloc==0 );
+  assert( pParse->apVarExpr==0 );
+  while( !db->mallocFailed && zSql[i]!=0 ){
+    assert( i>=0 );
+    pParse->sLastToken.z = (u8*)&zSql[i];
+    assert( pParse->sLastToken.dyn==0 );
+    pParse->sLastToken.n = sqlite3GetToken((unsigned char*)&zSql[i],&tokenType);
+    i += pParse->sLastToken.n;
+    if( i>mxSqlLen ){
+      pParse->rc = SQLITE_TOOBIG;
+      break;
+    }
+    switch( tokenType ){
+      case TK_SPACE:
+      case TK_COMMENT: {
+        if( db->u1.isInterrupted ){
+          pParse->rc = SQLITE_INTERRUPT;
+          sqlite3SetString(pzErrMsg, db, "interrupt");
+          goto abort_parse;
+        }
+        break;
+      }
+      case TK_ILLEGAL: {
+        sqlite3DbFree(db, *pzErrMsg);
+        *pzErrMsg = sqlite3MPrintf(db, "unrecognized token: \"%T\"",
+                        &pParse->sLastToken);
+        nErr++;
+        goto abort_parse;
+      }
+      case TK_SEMI: {
+        pParse->zTail = &zSql[i];
+        /* Fall thru into the default case */
+      }
+      default: {
+        sqlite3Parser(pEngine, tokenType, pParse->sLastToken, pParse);
+        lastTokenParsed = tokenType;
+        if( pParse->rc!=SQLITE_OK ){
+          goto abort_parse;
+        }
+        break;
+      }
+    }
+  }
+abort_parse:
+  if( zSql[i]==0 && nErr==0 && pParse->rc==SQLITE_OK ){
+    if( lastTokenParsed!=TK_SEMI ){
+      sqlite3Parser(pEngine, TK_SEMI, pParse->sLastToken, pParse);
+      pParse->zTail = &zSql[i];
+    }
+    sqlite3Parser(pEngine, 0, pParse->sLastToken, pParse);
+  }
+#ifdef YYTRACKMAXSTACKDEPTH
+  sqlite3StatusSet(SQLITE_STATUS_PARSER_STACK,
+      sqlite3ParserStackPeak(pEngine)
+  );
+#endif /* YYDEBUG */
+  sqlite3ParserFree(pEngine, sqlite3_free);
+  if( db->mallocFailed ){
+    pParse->rc = SQLITE_NOMEM;
+  }
+  if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
+    sqlite3SetString(&pParse->zErrMsg, db, "%s", sqlite3ErrStr(pParse->rc));
+  }
+  if( pParse->zErrMsg ){
+    if( *pzErrMsg==0 ){
+      *pzErrMsg = pParse->zErrMsg;
+    }else{
+      sqlite3DbFree(db, pParse->zErrMsg);
+    }
+    pParse->zErrMsg = 0;
+    nErr++;
+  }
+  if( pParse->pVdbe && pParse->nErr>0 && pParse->nested==0 ){
+    sqlite3VdbeDelete(pParse->pVdbe);
+    pParse->pVdbe = 0;
+  }
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  if( pParse->nested==0 ){
+    sqlite3DbFree(db, pParse->aTableLock);
+    pParse->aTableLock = 0;
+    pParse->nTableLock = 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3DbFree(db, pParse->apVtabLock);
+#endif
+
+  if( !IN_DECLARE_VTAB ){
+    /* If the pParse->declareVtab flag is set, do not delete any table 
+    ** structure built up in pParse->pNewTable. The calling code (see vtab.c)
+    ** will take responsibility for freeing the Table structure.
+    */
+    sqlite3DeleteTable(pParse->pNewTable);
+  }
+
+  sqlite3DeleteTrigger(db, pParse->pNewTrigger);
+  sqlite3DbFree(db, pParse->apVarExpr);
+  if( nErr>0 && (pParse->rc==SQLITE_OK || pParse->rc==SQLITE_DONE) ){
+    pParse->rc = SQLITE_ERROR;
+  }
+  return nErr;
+}
diff --git a/third_party/sqlite/src/trigger.c b/third_party/sqlite/src/trigger.c
new file mode 100755
index 0000000..760c708
--- /dev/null
+++ b/third_party/sqlite/src/trigger.c
@@ -0,0 +1,853 @@
+/*
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+**
+** $Id: trigger.c,v 1.128 2008/07/28 19:34:54 drh Exp $
+*/
+#include "sqliteInt.h"
+
+#ifndef SQLITE_OMIT_TRIGGER
+/*
+** Delete a linked list of TriggerStep structures.
+*/
+void sqlite3DeleteTriggerStep(sqlite3 *db, TriggerStep *pTriggerStep){
+  while( pTriggerStep ){
+    TriggerStep * pTmp = pTriggerStep;
+    pTriggerStep = pTriggerStep->pNext;
+
+    if( pTmp->target.dyn ) sqlite3DbFree(db, (char*)pTmp->target.z);
+    sqlite3ExprDelete(db, pTmp->pWhere);
+    sqlite3ExprListDelete(db, pTmp->pExprList);
+    sqlite3SelectDelete(db, pTmp->pSelect);
+    sqlite3IdListDelete(db, pTmp->pIdList);
+
+    sqlite3DbFree(db, pTmp);
+  }
+}
+
+/*
+** This is called by the parser when it sees a CREATE TRIGGER statement
+** up to the point of the BEGIN before the trigger actions.  A Trigger
+** structure is generated based on the information available and stored
+** in pParse->pNewTrigger.  After the trigger actions have been parsed, the
+** sqlite3FinishTrigger() function is called to complete the trigger
+** construction process.
+*/
+void sqlite3BeginTrigger(
+  Parse *pParse,      /* The parse context of the CREATE TRIGGER statement */
+  Token *pName1,      /* The name of the trigger */
+  Token *pName2,      /* The name of the trigger */
+  int tr_tm,          /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */
+  int op,             /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
+  IdList *pColumns,   /* column list if this is an UPDATE OF trigger */
+  SrcList *pTableName,/* The name of the table/view the trigger applies to */
+  Expr *pWhen,        /* WHEN clause */
+  int isTemp,         /* True if the TEMPORARY keyword is present */
+  int noErr           /* Suppress errors if the trigger already exists */
+){
+  Trigger *pTrigger = 0;
+  Table *pTab;
+  char *zName = 0;        /* Name of the trigger */
+  sqlite3 *db = pParse->db;
+  int iDb;                /* The database to store the trigger in */
+  Token *pName;           /* The unqualified db name */
+  DbFixer sFix;
+  int iTabDb;
+
+  assert( pName1!=0 );   /* pName1->z might be NULL, but not pName1 itself */
+  assert( pName2!=0 );
+  if( isTemp ){
+    /* If TEMP was specified, then the trigger name may not be qualified. */
+    if( pName2->n>0 ){
+      sqlite3ErrorMsg(pParse, "temporary trigger may not have qualified name");
+      goto trigger_cleanup;
+    }
+    iDb = 1;
+    pName = pName1;
+  }else{
+    /* Figure out the db that the the trigger will be created in */
+    iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
+    if( iDb<0 ){
+      goto trigger_cleanup;
+    }
+  }
+
+  /* If the trigger name was unqualified, and the table is a temp table,
+  ** then set iDb to 1 to create the trigger in the temporary database.
+  ** If sqlite3SrcListLookup() returns 0, indicating the table does not
+  ** exist, the error is caught by the block below.
+  */
+  if( !pTableName || db->mallocFailed ){
+    goto trigger_cleanup;
+  }
+  pTab = sqlite3SrcListLookup(pParse, pTableName);
+  if( pName2->n==0 && pTab && pTab->pSchema==db->aDb[1].pSchema ){
+    iDb = 1;
+  }
+
+  /* Ensure the table name matches database name and that the table exists */
+  if( db->mallocFailed ) goto trigger_cleanup;
+  assert( pTableName->nSrc==1 );
+  if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName) && 
+      sqlite3FixSrcList(&sFix, pTableName) ){
+    goto trigger_cleanup;
+  }
+  pTab = sqlite3SrcListLookup(pParse, pTableName);
+  if( !pTab ){
+    /* The table does not exist. */
+    goto trigger_cleanup;
+  }
+  if( IsVirtual(pTab) ){
+    sqlite3ErrorMsg(pParse, "cannot create triggers on virtual tables");
+    goto trigger_cleanup;
+  }
+
+  /* Check that the trigger name is not reserved and that no trigger of the
+  ** specified name exists */
+  zName = sqlite3NameFromToken(db, pName);
+  if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
+    goto trigger_cleanup;
+  }
+  if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash), zName,strlen(zName)) ){
+    if( !noErr ){
+      sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
+    }
+    goto trigger_cleanup;
+  }
+
+  /* Do not create a trigger on a system table */
+  if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
+    sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
+    pParse->nErr++;
+    goto trigger_cleanup;
+  }
+
+  /* INSTEAD of triggers are only for views and views only support INSTEAD
+  ** of triggers.
+  */
+  if( pTab->pSelect && tr_tm!=TK_INSTEAD ){
+    sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S", 
+        (tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
+    goto trigger_cleanup;
+  }
+  if( !pTab->pSelect && tr_tm==TK_INSTEAD ){
+    sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"
+        " trigger on table: %S", pTableName, 0);
+    goto trigger_cleanup;
+  }
+  iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  {
+    int code = SQLITE_CREATE_TRIGGER;
+    const char *zDb = db->aDb[iTabDb].zName;
+    const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
+    if( iTabDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
+    if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){
+      goto trigger_cleanup;
+    }
+    if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iTabDb),0,zDb)){
+      goto trigger_cleanup;
+    }
+  }
+#endif
+
+  /* INSTEAD OF triggers can only appear on views and BEFORE triggers
+  ** cannot appear on views.  So we might as well translate every
+  ** INSTEAD OF trigger into a BEFORE trigger.  It simplifies code
+  ** elsewhere.
+  */
+  if (tr_tm == TK_INSTEAD){
+    tr_tm = TK_BEFORE;
+  }
+
+  /* Build the Trigger object */
+  pTrigger = (Trigger*)sqlite3DbMallocZero(db, sizeof(Trigger));
+  if( pTrigger==0 ) goto trigger_cleanup;
+  pTrigger->name = zName;
+  zName = 0;
+  pTrigger->table = sqlite3DbStrDup(db, pTableName->a[0].zName);
+  pTrigger->pSchema = db->aDb[iDb].pSchema;
+  pTrigger->pTabSchema = pTab->pSchema;
+  pTrigger->op = op;
+  pTrigger->tr_tm = tr_tm==TK_BEFORE ? TRIGGER_BEFORE : TRIGGER_AFTER;
+  pTrigger->pWhen = sqlite3ExprDup(db, pWhen);
+  pTrigger->pColumns = sqlite3IdListDup(db, pColumns);
+  sqlite3TokenCopy(db, &pTrigger->nameToken,pName);
+  assert( pParse->pNewTrigger==0 );
+  pParse->pNewTrigger = pTrigger;
+
+trigger_cleanup:
+  sqlite3DbFree(db, zName);
+  sqlite3SrcListDelete(db, pTableName);
+  sqlite3IdListDelete(db, pColumns);
+  sqlite3ExprDelete(db, pWhen);
+  if( !pParse->pNewTrigger ){
+    sqlite3DeleteTrigger(db, pTrigger);
+  }else{
+    assert( pParse->pNewTrigger==pTrigger );
+  }
+}
+
+/*
+** This routine is called after all of the trigger actions have been parsed
+** in order to complete the process of building the trigger.
+*/
+void sqlite3FinishTrigger(
+  Parse *pParse,          /* Parser context */
+  TriggerStep *pStepList, /* The triggered program */
+  Token *pAll             /* Token that describes the complete CREATE TRIGGER */
+){
+  Trigger *pTrig = 0;     /* The trigger whose construction is finishing up */
+  sqlite3 *db = pParse->db;  /* The database */
+  DbFixer sFix;
+  int iDb;                   /* Database containing the trigger */
+
+  pTrig = pParse->pNewTrigger;
+  pParse->pNewTrigger = 0;
+  if( pParse->nErr || !pTrig ) goto triggerfinish_cleanup;
+  iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
+  pTrig->step_list = pStepList;
+  while( pStepList ){
+    pStepList->pTrig = pTrig;
+    pStepList = pStepList->pNext;
+  }
+  if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", &pTrig->nameToken) 
+          && sqlite3FixTriggerStep(&sFix, pTrig->step_list) ){
+    goto triggerfinish_cleanup;
+  }
+
+  /* if we are not initializing, and this trigger is not on a TEMP table, 
+  ** build the sqlite_master entry
+  */
+  if( !db->init.busy ){
+    Vdbe *v;
+    char *z;
+
+    /* Make an entry in the sqlite_master table */
+    v = sqlite3GetVdbe(pParse);
+    if( v==0 ) goto triggerfinish_cleanup;
+    sqlite3BeginWriteOperation(pParse, 0, iDb);
+    z = sqlite3DbStrNDup(db, (char*)pAll->z, pAll->n);
+    sqlite3NestedParse(pParse,
+       "INSERT INTO %Q.%s VALUES('trigger',%Q,%Q,0,'CREATE TRIGGER %q')",
+       db->aDb[iDb].zName, SCHEMA_TABLE(iDb), pTrig->name,
+       pTrig->table, z);
+    sqlite3DbFree(db, z);
+    sqlite3ChangeCookie(pParse, iDb);
+    sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0, sqlite3MPrintf(
+        db, "type='trigger' AND name='%q'", pTrig->name), P4_DYNAMIC
+    );
+  }
+
+  if( db->init.busy ){
+    int n;
+    Table *pTab;
+    Trigger *pDel;
+    pDel = sqlite3HashInsert(&db->aDb[iDb].pSchema->trigHash, 
+                     pTrig->name, strlen(pTrig->name), pTrig);
+    if( pDel ){
+      assert( pDel==pTrig );
+      db->mallocFailed = 1;
+      goto triggerfinish_cleanup;
+    }
+    n = strlen(pTrig->table) + 1;
+    pTab = sqlite3HashFind(&pTrig->pTabSchema->tblHash, pTrig->table, n);
+    assert( pTab!=0 );
+    pTrig->pNext = pTab->pTrigger;
+    pTab->pTrigger = pTrig;
+    pTrig = 0;
+  }
+
+triggerfinish_cleanup:
+  sqlite3DeleteTrigger(db, pTrig);
+  assert( !pParse->pNewTrigger );
+  sqlite3DeleteTriggerStep(db, pStepList);
+}
+
+/*
+** Make a copy of all components of the given trigger step.  This has
+** the effect of copying all Expr.token.z values into memory obtained
+** from sqlite3_malloc().  As initially created, the Expr.token.z values
+** all point to the input string that was fed to the parser.  But that
+** string is ephemeral - it will go away as soon as the sqlite3_exec()
+** call that started the parser exits.  This routine makes a persistent
+** copy of all the Expr.token.z strings so that the TriggerStep structure
+** will be valid even after the sqlite3_exec() call returns.
+*/
+static void sqlitePersistTriggerStep(sqlite3 *db, TriggerStep *p){
+  if( p->target.z ){
+    p->target.z = (u8*)sqlite3DbStrNDup(db, (char*)p->target.z, p->target.n);
+    p->target.dyn = 1;
+  }
+  if( p->pSelect ){
+    Select *pNew = sqlite3SelectDup(db, p->pSelect);
+    sqlite3SelectDelete(db, p->pSelect);
+    p->pSelect = pNew;
+  }
+  if( p->pWhere ){
+    Expr *pNew = sqlite3ExprDup(db, p->pWhere);
+    sqlite3ExprDelete(db, p->pWhere);
+    p->pWhere = pNew;
+  }
+  if( p->pExprList ){
+    ExprList *pNew = sqlite3ExprListDup(db, p->pExprList);
+    sqlite3ExprListDelete(db, p->pExprList);
+    p->pExprList = pNew;
+  }
+  if( p->pIdList ){
+    IdList *pNew = sqlite3IdListDup(db, p->pIdList);
+    sqlite3IdListDelete(db, p->pIdList);
+    p->pIdList = pNew;
+  }
+}
+
+/*
+** Turn a SELECT statement (that the pSelect parameter points to) into
+** a trigger step.  Return a pointer to a TriggerStep structure.
+**
+** The parser calls this routine when it finds a SELECT statement in
+** body of a TRIGGER.  
+*/
+TriggerStep *sqlite3TriggerSelectStep(sqlite3 *db, Select *pSelect){
+  TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
+  if( pTriggerStep==0 ) {
+    sqlite3SelectDelete(db, pSelect);
+    return 0;
+  }
+
+  pTriggerStep->op = TK_SELECT;
+  pTriggerStep->pSelect = pSelect;
+  pTriggerStep->orconf = OE_Default;
+  sqlitePersistTriggerStep(db, pTriggerStep);
+
+  return pTriggerStep;
+}
+
+/*
+** Build a trigger step out of an INSERT statement.  Return a pointer
+** to the new trigger step.
+**
+** The parser calls this routine when it sees an INSERT inside the
+** body of a trigger.
+*/
+TriggerStep *sqlite3TriggerInsertStep(
+  sqlite3 *db,        /* The database connection */
+  Token *pTableName,  /* Name of the table into which we insert */
+  IdList *pColumn,    /* List of columns in pTableName to insert into */
+  ExprList *pEList,   /* The VALUE clause: a list of values to be inserted */
+  Select *pSelect,    /* A SELECT statement that supplies values */
+  int orconf          /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */
+){
+  TriggerStep *pTriggerStep;
+
+  assert(pEList == 0 || pSelect == 0);
+  assert(pEList != 0 || pSelect != 0 || db->mallocFailed);
+
+  pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
+  if( pTriggerStep ){
+    pTriggerStep->op = TK_INSERT;
+    pTriggerStep->pSelect = pSelect;
+    pTriggerStep->target  = *pTableName;
+    pTriggerStep->pIdList = pColumn;
+    pTriggerStep->pExprList = pEList;
+    pTriggerStep->orconf = orconf;
+    sqlitePersistTriggerStep(db, pTriggerStep);
+  }else{
+    sqlite3IdListDelete(db, pColumn);
+    sqlite3ExprListDelete(db, pEList);
+    sqlite3SelectDelete(db, pSelect);
+  }
+
+  return pTriggerStep;
+}
+
+/*
+** Construct a trigger step that implements an UPDATE statement and return
+** a pointer to that trigger step.  The parser calls this routine when it
+** sees an UPDATE statement inside the body of a CREATE TRIGGER.
+*/
+TriggerStep *sqlite3TriggerUpdateStep(
+  sqlite3 *db,         /* The database connection */
+  Token *pTableName,   /* Name of the table to be updated */
+  ExprList *pEList,    /* The SET clause: list of column and new values */
+  Expr *pWhere,        /* The WHERE clause */
+  int orconf           /* The conflict algorithm. (OE_Abort, OE_Ignore, etc) */
+){
+  TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
+  if( pTriggerStep==0 ){
+     sqlite3ExprListDelete(db, pEList);
+     sqlite3ExprDelete(db, pWhere);
+     return 0;
+  }
+
+  pTriggerStep->op = TK_UPDATE;
+  pTriggerStep->target  = *pTableName;
+  pTriggerStep->pExprList = pEList;
+  pTriggerStep->pWhere = pWhere;
+  pTriggerStep->orconf = orconf;
+  sqlitePersistTriggerStep(db, pTriggerStep);
+
+  return pTriggerStep;
+}
+
+/*
+** Construct a trigger step that implements a DELETE statement and return
+** a pointer to that trigger step.  The parser calls this routine when it
+** sees a DELETE statement inside the body of a CREATE TRIGGER.
+*/
+TriggerStep *sqlite3TriggerDeleteStep(
+  sqlite3 *db,            /* Database connection */
+  Token *pTableName,      /* The table from which rows are deleted */
+  Expr *pWhere            /* The WHERE clause */
+){
+  TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
+  if( pTriggerStep==0 ){
+    sqlite3ExprDelete(db, pWhere);
+    return 0;
+  }
+
+  pTriggerStep->op = TK_DELETE;
+  pTriggerStep->target  = *pTableName;
+  pTriggerStep->pWhere = pWhere;
+  pTriggerStep->orconf = OE_Default;
+  sqlitePersistTriggerStep(db, pTriggerStep);
+
+  return pTriggerStep;
+}
+
+/* 
+** Recursively delete a Trigger structure
+*/
+void sqlite3DeleteTrigger(sqlite3 *db, Trigger *pTrigger){
+  if( pTrigger==0 ) return;
+  sqlite3DeleteTriggerStep(db, pTrigger->step_list);
+  sqlite3DbFree(db, pTrigger->name);
+  sqlite3DbFree(db, pTrigger->table);
+  sqlite3ExprDelete(db, pTrigger->pWhen);
+  sqlite3IdListDelete(db, pTrigger->pColumns);
+  if( pTrigger->nameToken.dyn ) sqlite3DbFree(db, (char*)pTrigger->nameToken.z);
+  sqlite3DbFree(db, pTrigger);
+}
+
+/*
+** This function is called to drop a trigger from the database schema. 
+**
+** This may be called directly from the parser and therefore identifies
+** the trigger by name.  The sqlite3DropTriggerPtr() routine does the
+** same job as this routine except it takes a pointer to the trigger
+** instead of the trigger name.
+**/
+void sqlite3DropTrigger(Parse *pParse, SrcList *pName, int noErr){
+  Trigger *pTrigger = 0;
+  int i;
+  const char *zDb;
+  const char *zName;
+  int nName;
+  sqlite3 *db = pParse->db;
+
+  if( db->mallocFailed ) goto drop_trigger_cleanup;
+  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
+    goto drop_trigger_cleanup;
+  }
+
+  assert( pName->nSrc==1 );
+  zDb = pName->a[0].zDatabase;
+  zName = pName->a[0].zName;
+  nName = strlen(zName);
+  for(i=OMIT_TEMPDB; i<db->nDb; i++){
+    int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
+    if( zDb && sqlite3StrICmp(db->aDb[j].zName, zDb) ) continue;
+    pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName, nName);
+    if( pTrigger ) break;
+  }
+  if( !pTrigger ){
+    if( !noErr ){
+      sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0);
+    }
+    goto drop_trigger_cleanup;
+  }
+  sqlite3DropTriggerPtr(pParse, pTrigger);
+
+drop_trigger_cleanup:
+  sqlite3SrcListDelete(db, pName);
+}
+
+/*
+** Return a pointer to the Table structure for the table that a trigger
+** is set on.
+*/
+static Table *tableOfTrigger(Trigger *pTrigger){
+  int n = strlen(pTrigger->table) + 1;
+  return sqlite3HashFind(&pTrigger->pTabSchema->tblHash, pTrigger->table, n);
+}
+
+
+/*
+** Drop a trigger given a pointer to that trigger. 
+*/
+void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){
+  Table   *pTable;
+  Vdbe *v;
+  sqlite3 *db = pParse->db;
+  int iDb;
+
+  iDb = sqlite3SchemaToIndex(pParse->db, pTrigger->pSchema);
+  assert( iDb>=0 && iDb<db->nDb );
+  pTable = tableOfTrigger(pTrigger);
+  assert( pTable );
+  assert( pTable->pSchema==pTrigger->pSchema || iDb==1 );
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  {
+    int code = SQLITE_DROP_TRIGGER;
+    const char *zDb = db->aDb[iDb].zName;
+    const char *zTab = SCHEMA_TABLE(iDb);
+    if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;
+    if( sqlite3AuthCheck(pParse, code, pTrigger->name, pTable->zName, zDb) ||
+      sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
+      return;
+    }
+  }
+#endif
+
+  /* Generate code to destroy the database record of the trigger.
+  */
+  assert( pTable!=0 );
+  if( (v = sqlite3GetVdbe(pParse))!=0 ){
+    int base;
+    static const VdbeOpList dropTrigger[] = {
+      { OP_Rewind,     0, ADDR(9),  0},
+      { OP_String8,    0, 1,        0}, /* 1 */
+      { OP_Column,     0, 1,        2},
+      { OP_Ne,         2, ADDR(8),  1},
+      { OP_String8,    0, 1,        0}, /* 4: "trigger" */
+      { OP_Column,     0, 0,        2},
+      { OP_Ne,         2, ADDR(8),  1},
+      { OP_Delete,     0, 0,        0},
+      { OP_Next,       0, ADDR(1),  0}, /* 8 */
+    };
+
+    sqlite3BeginWriteOperation(pParse, 0, iDb);
+    sqlite3OpenMasterTable(pParse, iDb);
+    base = sqlite3VdbeAddOpList(v,  ArraySize(dropTrigger), dropTrigger);
+    sqlite3VdbeChangeP4(v, base+1, pTrigger->name, 0);
+    sqlite3VdbeChangeP4(v, base+4, "trigger", P4_STATIC);
+    sqlite3ChangeCookie(pParse, iDb);
+    sqlite3VdbeAddOp2(v, OP_Close, 0, 0);
+    sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->name, 0);
+  }
+}
+
+/*
+** Remove a trigger from the hash tables of the sqlite* pointer.
+*/
+void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){
+  Trigger *pTrigger;
+  int nName = strlen(zName);
+  pTrigger = sqlite3HashInsert(&(db->aDb[iDb].pSchema->trigHash),
+                               zName, nName, 0);
+  if( pTrigger ){
+    Table *pTable = tableOfTrigger(pTrigger);
+    assert( pTable!=0 );
+    if( pTable->pTrigger == pTrigger ){
+      pTable->pTrigger = pTrigger->pNext;
+    }else{
+      Trigger *cc = pTable->pTrigger;
+      while( cc ){ 
+        if( cc->pNext == pTrigger ){
+          cc->pNext = cc->pNext->pNext;
+          break;
+        }
+        cc = cc->pNext;
+      }
+      assert(cc);
+    }
+    sqlite3DeleteTrigger(db, pTrigger);
+    db->flags |= SQLITE_InternChanges;
+  }
+}
+
+/*
+** pEList is the SET clause of an UPDATE statement.  Each entry
+** in pEList is of the format <id>=<expr>.  If any of the entries
+** in pEList have an <id> which matches an identifier in pIdList,
+** then return TRUE.  If pIdList==NULL, then it is considered a
+** wildcard that matches anything.  Likewise if pEList==NULL then
+** it matches anything so always return true.  Return false only
+** if there is no match.
+*/
+static int checkColumnOverLap(IdList *pIdList, ExprList *pEList){
+  int e;
+  if( !pIdList || !pEList ) return 1;
+  for(e=0; e<pEList->nExpr; e++){
+    if( sqlite3IdListIndex(pIdList, pEList->a[e].zName)>=0 ) return 1;
+  }
+  return 0; 
+}
+
+/*
+** Return a bit vector to indicate what kind of triggers exist for operation
+** "op" on table pTab.  If pChanges is not NULL then it is a list of columns
+** that are being updated.  Triggers only match if the ON clause of the
+** trigger definition overlaps the set of columns being updated.
+**
+** The returned bit vector is some combination of TRIGGER_BEFORE and
+** TRIGGER_AFTER.
+*/
+int sqlite3TriggersExist(
+  Parse *pParse,          /* Used to check for recursive triggers */
+  Table *pTab,            /* The table the contains the triggers */
+  int op,                 /* one of TK_DELETE, TK_INSERT, TK_UPDATE */
+  ExprList *pChanges      /* Columns that change in an UPDATE statement */
+){
+  Trigger *pTrigger;
+  int mask = 0;
+
+  pTrigger = IsVirtual(pTab) ? 0 : pTab->pTrigger;
+  while( pTrigger ){
+    if( pTrigger->op==op && checkColumnOverLap(pTrigger->pColumns, pChanges) ){
+      mask |= pTrigger->tr_tm;
+    }
+    pTrigger = pTrigger->pNext;
+  }
+  return mask;
+}
+
+/*
+** Convert the pStep->target token into a SrcList and return a pointer
+** to that SrcList.
+**
+** This routine adds a specific database name, if needed, to the target when
+** forming the SrcList.  This prevents a trigger in one database from
+** referring to a target in another database.  An exception is when the
+** trigger is in TEMP in which case it can refer to any other database it
+** wants.
+*/
+static SrcList *targetSrcList(
+  Parse *pParse,       /* The parsing context */
+  TriggerStep *pStep   /* The trigger containing the target token */
+){
+  Token sDb;           /* Dummy database name token */
+  int iDb;             /* Index of the database to use */
+  SrcList *pSrc;       /* SrcList to be returned */
+
+  iDb = sqlite3SchemaToIndex(pParse->db, pStep->pTrig->pSchema);
+  if( iDb==0 || iDb>=2 ){
+    assert( iDb<pParse->db->nDb );
+    sDb.z = (u8*)pParse->db->aDb[iDb].zName;
+    sDb.n = strlen((char*)sDb.z);
+    pSrc = sqlite3SrcListAppend(pParse->db, 0, &sDb, &pStep->target);
+  } else {
+    pSrc = sqlite3SrcListAppend(pParse->db, 0, &pStep->target, 0);
+  }
+  return pSrc;
+}
+
+/*
+** Generate VDBE code for zero or more statements inside the body of a
+** trigger.  
+*/
+static int codeTriggerProgram(
+  Parse *pParse,            /* The parser context */
+  TriggerStep *pStepList,   /* List of statements inside the trigger body */
+  int orconfin              /* Conflict algorithm. (OE_Abort, etc) */  
+){
+  TriggerStep * pTriggerStep = pStepList;
+  int orconf;
+  Vdbe *v = pParse->pVdbe;
+  sqlite3 *db = pParse->db;
+
+  assert( pTriggerStep!=0 );
+  assert( v!=0 );
+  sqlite3VdbeAddOp2(v, OP_ContextPush, 0, 0);
+  VdbeComment((v, "begin trigger %s", pStepList->pTrig->name));
+  while( pTriggerStep ){
+    orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin;
+    pParse->trigStack->orconf = orconf;
+    switch( pTriggerStep->op ){
+      case TK_SELECT: {
+        Select *ss = sqlite3SelectDup(db, pTriggerStep->pSelect);
+        if( ss ){
+          SelectDest dest;
+
+          sqlite3SelectDestInit(&dest, SRT_Discard, 0);
+          sqlite3SelectResolve(pParse, ss, 0);
+          sqlite3Select(pParse, ss, &dest, 0, 0, 0);
+          sqlite3SelectDelete(db, ss);
+        }
+        break;
+      }
+      case TK_UPDATE: {
+        SrcList *pSrc;
+        pSrc = targetSrcList(pParse, pTriggerStep);
+        sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0);
+        sqlite3Update(pParse, pSrc,
+                sqlite3ExprListDup(db, pTriggerStep->pExprList), 
+                sqlite3ExprDup(db, pTriggerStep->pWhere), orconf);
+        sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0);
+        break;
+      }
+      case TK_INSERT: {
+        SrcList *pSrc;
+        pSrc = targetSrcList(pParse, pTriggerStep);
+        sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0);
+        sqlite3Insert(pParse, pSrc,
+          sqlite3ExprListDup(db, pTriggerStep->pExprList), 
+          sqlite3SelectDup(db, pTriggerStep->pSelect), 
+          sqlite3IdListDup(db, pTriggerStep->pIdList), orconf);
+        sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0);
+        break;
+      }
+      case TK_DELETE: {
+        SrcList *pSrc;
+        sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0);
+        pSrc = targetSrcList(pParse, pTriggerStep);
+        sqlite3DeleteFrom(pParse, pSrc, 
+                          sqlite3ExprDup(db, pTriggerStep->pWhere));
+        sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0);
+        break;
+      }
+      default:
+        assert(0);
+    } 
+    pTriggerStep = pTriggerStep->pNext;
+  }
+  sqlite3VdbeAddOp2(v, OP_ContextPop, 0, 0);
+  VdbeComment((v, "end trigger %s", pStepList->pTrig->name));
+
+  return 0;
+}
+
+/*
+** This is called to code FOR EACH ROW triggers.
+**
+** When the code that this function generates is executed, the following 
+** must be true:
+**
+** 1. No cursors may be open in the main database.  (But newIdx and oldIdx
+**    can be indices of cursors in temporary tables.  See below.)
+**
+** 2. If the triggers being coded are ON INSERT or ON UPDATE triggers, then
+**    a temporary vdbe cursor (index newIdx) must be open and pointing at
+**    a row containing values to be substituted for new.* expressions in the
+**    trigger program(s).
+**
+** 3. If the triggers being coded are ON DELETE or ON UPDATE triggers, then
+**    a temporary vdbe cursor (index oldIdx) must be open and pointing at
+**    a row containing values to be substituted for old.* expressions in the
+**    trigger program(s).
+**
+** If they are not NULL, the piOldColMask and piNewColMask output variables
+** are set to values that describe the columns used by the trigger program
+** in the OLD.* and NEW.* tables respectively. If column N of the 
+** pseudo-table is read at least once, the corresponding bit of the output
+** mask is set. If a column with an index greater than 32 is read, the
+** output mask is set to the special value 0xffffffff.
+**
+*/
+int sqlite3CodeRowTrigger(
+  Parse *pParse,       /* Parse context */
+  int op,              /* One of TK_UPDATE, TK_INSERT, TK_DELETE */
+  ExprList *pChanges,  /* Changes list for any UPDATE OF triggers */
+  int tr_tm,           /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
+  Table *pTab,         /* The table to code triggers from */
+  int newIdx,          /* The indice of the "new" row to access */
+  int oldIdx,          /* The indice of the "old" row to access */
+  int orconf,          /* ON CONFLICT policy */
+  int ignoreJump,      /* Instruction to jump to for RAISE(IGNORE) */
+  u32 *piOldColMask,   /* OUT: Mask of columns used from the OLD.* table */
+  u32 *piNewColMask    /* OUT: Mask of columns used from the NEW.* table */
+){
+  Trigger *p;
+  sqlite3 *db = pParse->db;
+  TriggerStack trigStackEntry;
+
+  trigStackEntry.oldColMask = 0;
+  trigStackEntry.newColMask = 0;
+
+  assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE);
+  assert(tr_tm == TRIGGER_BEFORE || tr_tm == TRIGGER_AFTER );
+
+  assert(newIdx != -1 || oldIdx != -1);
+
+  for(p=pTab->pTrigger; p; p=p->pNext){
+    int fire_this = 0;
+
+    /* Determine whether we should code this trigger */
+    if( 
+      p->op==op && 
+      p->tr_tm==tr_tm && 
+      (p->pSchema==p->pTabSchema || p->pSchema==db->aDb[1].pSchema) &&
+      (op!=TK_UPDATE||!p->pColumns||checkColumnOverLap(p->pColumns,pChanges))
+    ){
+      TriggerStack *pS;      /* Pointer to trigger-stack entry */
+      for(pS=pParse->trigStack; pS && p!=pS->pTrigger; pS=pS->pNext){}
+      if( !pS ){
+        fire_this = 1;
+      }
+#if 0    /* Give no warning for recursive triggers.  Just do not do them */
+      else{
+        sqlite3ErrorMsg(pParse, "recursive triggers not supported (%s)",
+            p->name);
+        return SQLITE_ERROR;
+      }
+#endif
+    }
+ 
+    if( fire_this ){
+      int endTrigger;
+      Expr * whenExpr;
+      AuthContext sContext;
+      NameContext sNC;
+
+#ifndef SQLITE_OMIT_TRACE
+      sqlite3VdbeAddOp4(pParse->pVdbe, OP_Trace, 0, 0, 0,
+                        sqlite3MPrintf(db, "-- TRIGGER %s", p->name),
+                        P4_DYNAMIC);
+#endif
+      memset(&sNC, 0, sizeof(sNC));
+      sNC.pParse = pParse;
+
+      /* Push an entry on to the trigger stack */
+      trigStackEntry.pTrigger = p;
+      trigStackEntry.newIdx = newIdx;
+      trigStackEntry.oldIdx = oldIdx;
+      trigStackEntry.pTab = pTab;
+      trigStackEntry.pNext = pParse->trigStack;
+      trigStackEntry.ignoreJump = ignoreJump;
+      pParse->trigStack = &trigStackEntry;
+      sqlite3AuthContextPush(pParse, &sContext, p->name);
+
+      /* code the WHEN clause */
+      endTrigger = sqlite3VdbeMakeLabel(pParse->pVdbe);
+      whenExpr = sqlite3ExprDup(db, p->pWhen);
+      if( db->mallocFailed || sqlite3ExprResolveNames(&sNC, whenExpr) ){
+        pParse->trigStack = trigStackEntry.pNext;
+        sqlite3ExprDelete(db, whenExpr);
+        return 1;
+      }
+      sqlite3ExprIfFalse(pParse, whenExpr, endTrigger, SQLITE_JUMPIFNULL);
+      sqlite3ExprDelete(db, whenExpr);
+
+      codeTriggerProgram(pParse, p->step_list, orconf); 
+
+      /* Pop the entry off the trigger stack */
+      pParse->trigStack = trigStackEntry.pNext;
+      sqlite3AuthContextPop(&sContext);
+
+      sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger);
+    }
+  }
+  if( piOldColMask ) *piOldColMask |= trigStackEntry.oldColMask;
+  if( piNewColMask ) *piNewColMask |= trigStackEntry.newColMask;
+  return 0;
+}
+#endif /* !defined(SQLITE_OMIT_TRIGGER) */
diff --git a/third_party/sqlite/src/update.c b/third_party/sqlite/src/update.c
new file mode 100755
index 0000000..7647d4a
--- /dev/null
+++ b/third_party/sqlite/src/update.c
@@ -0,0 +1,678 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains C code routines that are called by the parser
+** to handle UPDATE statements.
+**
+** $Id: update.c,v 1.181 2008/07/28 19:34:54 drh Exp $
+*/
+#include "sqliteInt.h"
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Forward declaration */
+static void updateVirtualTable(
+  Parse *pParse,       /* The parsing context */
+  SrcList *pSrc,       /* The virtual table to be modified */
+  Table *pTab,         /* The virtual table */
+  ExprList *pChanges,  /* The columns to change in the UPDATE statement */
+  Expr *pRowidExpr,    /* Expression used to recompute the rowid */
+  int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */
+  Expr *pWhere         /* WHERE clause of the UPDATE statement */
+);
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** The most recently coded instruction was an OP_Column to retrieve the
+** i-th column of table pTab. This routine sets the P4 parameter of the 
+** OP_Column to the default value, if any.
+**
+** The default value of a column is specified by a DEFAULT clause in the 
+** column definition. This was either supplied by the user when the table
+** was created, or added later to the table definition by an ALTER TABLE
+** command. If the latter, then the row-records in the table btree on disk
+** may not contain a value for the column and the default value, taken
+** from the P4 parameter of the OP_Column instruction, is returned instead.
+** If the former, then all row-records are guaranteed to include a value
+** for the column and the P4 value is not required.
+**
+** Column definitions created by an ALTER TABLE command may only have 
+** literal default values specified: a number, null or a string. (If a more
+** complicated default expression value was provided, it is evaluated 
+** when the ALTER TABLE is executed and one of the literal values written
+** into the sqlite_master table.)
+**
+** Therefore, the P4 parameter is only required if the default value for
+** the column is a literal number, string or null. The sqlite3ValueFromExpr()
+** function is capable of transforming these types of expressions into
+** sqlite3_value objects.
+*/
+void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i){
+  if( pTab && !pTab->pSelect ){
+    sqlite3_value *pValue;
+    u8 enc = ENC(sqlite3VdbeDb(v));
+    Column *pCol = &pTab->aCol[i];
+    VdbeComment((v, "%s.%s", pTab->zName, pCol->zName));
+    assert( i<pTab->nCol );
+    sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, 
+                         pCol->affinity, &pValue);
+    if( pValue ){
+      sqlite3VdbeChangeP4(v, -1, (const char *)pValue, P4_MEM);
+    }
+  }
+}
+
+/*
+** Process an UPDATE statement.
+**
+**   UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;
+**          \_______/ \________/     \______/       \________________/
+*            onError   pTabList      pChanges             pWhere
+*/
+void sqlite3Update(
+  Parse *pParse,         /* The parser context */
+  SrcList *pTabList,     /* The table in which we should change things */
+  ExprList *pChanges,    /* Things to be changed */
+  Expr *pWhere,          /* The WHERE clause.  May be null */
+  int onError            /* How to handle constraint errors */
+){
+  int i, j;              /* Loop counters */
+  Table *pTab;           /* The table to be updated */
+  int addr = 0;          /* VDBE instruction address of the start of the loop */
+  WhereInfo *pWInfo;     /* Information about the WHERE clause */
+  Vdbe *v;               /* The virtual database engine */
+  Index *pIdx;           /* For looping over indices */
+  int nIdx;              /* Number of indices that need updating */
+  int iCur;              /* VDBE Cursor number of pTab */
+  sqlite3 *db;           /* The database structure */
+  int *aRegIdx = 0;      /* One register assigned to each index to be updated */
+  int *aXRef = 0;        /* aXRef[i] is the index in pChanges->a[] of the
+                         ** an expression for the i-th column of the table.
+                         ** aXRef[i]==-1 if the i-th column is not changed. */
+  int chngRowid;         /* True if the record number is being changed */
+  Expr *pRowidExpr = 0;  /* Expression defining the new record number */
+  int openAll = 0;       /* True if all indices need to be opened */
+  AuthContext sContext;  /* The authorization context */
+  NameContext sNC;       /* The name-context to resolve expressions in */
+  int iDb;               /* Database containing the table being updated */
+  int j1;                /* Addresses of jump instructions */
+  int okOnePass;         /* True for one-pass algorithm without the FIFO */
+
+#ifndef SQLITE_OMIT_TRIGGER
+  int isView;                  /* Trying to update a view */
+  int triggers_exist = 0;      /* True if any row triggers exist */
+#endif
+  int iBeginAfterTrigger;      /* Address of after trigger program */
+  int iEndAfterTrigger;        /* Exit of after trigger program */
+  int iBeginBeforeTrigger;     /* Address of before trigger program */
+  int iEndBeforeTrigger;       /* Exit of before trigger program */
+  u32 old_col_mask = 0;        /* Mask of OLD.* columns in use */
+  u32 new_col_mask = 0;        /* Mask of NEW.* columns in use */
+
+  int newIdx      = -1;  /* index of trigger "new" temp table       */
+  int oldIdx      = -1;  /* index of trigger "old" temp table       */
+
+  /* Register Allocations */
+  int regRowCount = 0;   /* A count of rows changed */
+  int regOldRowid;       /* The old rowid */
+  int regNewRowid;       /* The new rowid */
+  int regData;           /* New data for the row */
+
+  sContext.pParse = 0;
+  db = pParse->db;
+  if( pParse->nErr || db->mallocFailed ){
+    goto update_cleanup;
+  }
+  assert( pTabList->nSrc==1 );
+
+  /* Locate the table which we want to update. 
+  */
+  pTab = sqlite3SrcListLookup(pParse, pTabList);
+  if( pTab==0 ) goto update_cleanup;
+  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+
+  /* Figure out if we have any triggers and if the table being
+  ** updated is a view
+  */
+#ifndef SQLITE_OMIT_TRIGGER
+  triggers_exist = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges);
+  isView = pTab->pSelect!=0;
+#else
+# define triggers_exist 0
+# define isView 0
+#endif
+#ifdef SQLITE_OMIT_VIEW
+# undef isView
+# define isView 0
+#endif
+
+  if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
+    goto update_cleanup;
+  }
+  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
+    goto update_cleanup;
+  }
+  aXRef = sqlite3DbMallocRaw(db, sizeof(int) * pTab->nCol );
+  if( aXRef==0 ) goto update_cleanup;
+  for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;
+
+  /* If there are FOR EACH ROW triggers, allocate cursors for the
+  ** special OLD and NEW tables
+  */
+  if( triggers_exist ){
+    newIdx = pParse->nTab++;
+    oldIdx = pParse->nTab++;
+  }
+
+  /* Allocate a cursors for the main database table and for all indices.
+  ** The index cursors might not be used, but if they are used they
+  ** need to occur right after the database cursor.  So go ahead and
+  ** allocate enough space, just in case.
+  */
+  pTabList->a[0].iCursor = iCur = pParse->nTab++;
+  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+    pParse->nTab++;
+  }
+
+  /* Initialize the name-context */
+  memset(&sNC, 0, sizeof(sNC));
+  sNC.pParse = pParse;
+  sNC.pSrcList = pTabList;
+
+  /* Resolve the column names in all the expressions of the
+  ** of the UPDATE statement.  Also find the column index
+  ** for each column to be updated in the pChanges array.  For each
+  ** column to be updated, make sure we have authorization to change
+  ** that column.
+  */
+  chngRowid = 0;
+  for(i=0; i<pChanges->nExpr; i++){
+    if( sqlite3ExprResolveNames(&sNC, pChanges->a[i].pExpr) ){
+      goto update_cleanup;
+    }
+    for(j=0; j<pTab->nCol; j++){
+      if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){
+        if( j==pTab->iPKey ){
+          chngRowid = 1;
+          pRowidExpr = pChanges->a[i].pExpr;
+        }
+        aXRef[j] = i;
+        break;
+      }
+    }
+    if( j>=pTab->nCol ){
+      if( sqlite3IsRowid(pChanges->a[i].zName) ){
+        chngRowid = 1;
+        pRowidExpr = pChanges->a[i].pExpr;
+      }else{
+        sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName);
+        goto update_cleanup;
+      }
+    }
+#ifndef SQLITE_OMIT_AUTHORIZATION
+    {
+      int rc;
+      rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
+                           pTab->aCol[j].zName, db->aDb[iDb].zName);
+      if( rc==SQLITE_DENY ){
+        goto update_cleanup;
+      }else if( rc==SQLITE_IGNORE ){
+        aXRef[j] = -1;
+      }
+    }
+#endif
+  }
+
+  /* Allocate memory for the array aRegIdx[].  There is one entry in the
+  ** array for each index associated with table being updated.  Fill in
+  ** the value with a register number for indices that are to be used
+  ** and with zero for unused indices.
+  */
+  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
+  if( nIdx>0 ){
+    aRegIdx = sqlite3DbMallocRaw(db, sizeof(Index*) * nIdx );
+    if( aRegIdx==0 ) goto update_cleanup;
+  }
+  for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
+    int reg;
+    if( chngRowid ){
+      reg = ++pParse->nMem;
+    }else{
+      reg = 0;
+      for(i=0; i<pIdx->nColumn; i++){
+        if( aXRef[pIdx->aiColumn[i]]>=0 ){
+          reg = ++pParse->nMem;
+          break;
+        }
+      }
+    }
+    aRegIdx[j] = reg;
+  }
+
+  /* Allocate a block of register used to store the change record
+  ** sent to sqlite3GenerateConstraintChecks().  There are either
+  ** one or two registers for holding the rowid.  One rowid register
+  ** is used if chngRowid is false and two are used if chngRowid is
+  ** true.  Following these are pTab->nCol register holding column
+  ** data.
+  */
+  regOldRowid = regNewRowid = pParse->nMem + 1;
+  pParse->nMem += pTab->nCol + 1;
+  if( chngRowid ){
+    regNewRowid++;
+    pParse->nMem++;
+  }
+  regData = regNewRowid+1;
+ 
+
+  /* Begin generating code.
+  */
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 ) goto update_cleanup;
+  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
+  sqlite3BeginWriteOperation(pParse, 1, iDb);
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  /* Virtual tables must be handled separately */
+  if( IsVirtual(pTab) ){
+    updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
+                       pWhere);
+    pWhere = 0;
+    pTabList = 0;
+    goto update_cleanup;
+  }
+#endif
+
+  /* Start the view context
+  */
+  if( isView ){
+    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
+  }
+
+  /* Generate the code for triggers.
+  */
+  if( triggers_exist ){
+    int iGoto;
+
+    /* Create pseudo-tables for NEW and OLD
+    */
+    sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
+    sqlite3VdbeAddOp2(v, OP_OpenPseudo, oldIdx, 0);
+    sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
+    sqlite3VdbeAddOp2(v, OP_OpenPseudo, newIdx, 0);
+
+    iGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
+    addr = sqlite3VdbeMakeLabel(v);
+    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
+    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab,
+          newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){
+      goto update_cleanup;
+    }
+    iEndBeforeTrigger = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
+    iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
+    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, 
+          newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){
+      goto update_cleanup;
+    }
+    iEndAfterTrigger = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
+    sqlite3VdbeJumpHere(v, iGoto);
+  }
+
+  /* If we are trying to update a view, realize that view into
+  ** a ephemeral table.
+  */
+  if( isView ){
+    sqlite3MaterializeView(pParse, pTab->pSelect, pWhere, iCur);
+  }
+
+  /* Resolve the column names in all the expressions in the
+  ** WHERE clause.
+  */
+  if( sqlite3ExprResolveNames(&sNC, pWhere) ){
+    goto update_cleanup;
+  }
+
+  /* Begin the database scan
+  */
+  sqlite3VdbeAddOp2(v, OP_Null, 0, regOldRowid);
+  pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0,
+                             WHERE_ONEPASS_DESIRED);
+  if( pWInfo==0 ) goto update_cleanup;
+  okOnePass = pWInfo->okOnePass;
+
+  /* Remember the rowid of every item to be updated.
+  */
+  sqlite3VdbeAddOp2(v, IsVirtual(pTab)?OP_VRowid:OP_Rowid, iCur, regOldRowid);
+  if( !okOnePass ) sqlite3VdbeAddOp2(v, OP_FifoWrite, regOldRowid, 0);
+
+  /* End the database scan loop.
+  */
+  sqlite3WhereEnd(pWInfo);
+
+  /* Initialize the count of updated rows
+  */
+  if( db->flags & SQLITE_CountRows && !pParse->trigStack ){
+    regRowCount = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
+  }
+
+  if( !isView && !IsVirtual(pTab) ){
+    /* 
+    ** Open every index that needs updating.  Note that if any
+    ** index could potentially invoke a REPLACE conflict resolution 
+    ** action, then we need to open all indices because we might need
+    ** to be deleting some records.
+    */
+    if( !okOnePass ) sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenWrite); 
+    if( onError==OE_Replace ){
+      openAll = 1;
+    }else{
+      openAll = 0;
+      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+        if( pIdx->onError==OE_Replace ){
+          openAll = 1;
+          break;
+        }
+      }
+    }
+    for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
+      if( openAll || aRegIdx[i]>0 ){
+        KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
+        sqlite3VdbeAddOp4(v, OP_OpenWrite, iCur+i+1, pIdx->tnum, iDb,
+                       (char*)pKey, P4_KEYINFO_HANDOFF);
+        assert( pParse->nTab>iCur+i+1 );
+      }
+    }
+  }
+  
+  /* Jump back to this point if a trigger encounters an IGNORE constraint. */
+  if( triggers_exist ){
+    sqlite3VdbeResolveLabel(v, addr);
+  }
+
+  /* Top of the update loop */
+  if( okOnePass ){
+    int a1 = sqlite3VdbeAddOp1(v, OP_NotNull, regOldRowid);
+    addr = sqlite3VdbeAddOp0(v, OP_Goto);
+    sqlite3VdbeJumpHere(v, a1);
+  }else{
+    addr = sqlite3VdbeAddOp2(v, OP_FifoRead, regOldRowid, 0);
+  }
+
+  if( triggers_exist ){
+    int regRowid;
+    int regRow;
+    int regCols;
+
+    /* Make cursor iCur point to the record that is being updated.
+    */
+    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid);
+
+    /* Generate the OLD table
+    */
+    regRowid = sqlite3GetTempReg(pParse);
+    regRow = sqlite3GetTempReg(pParse);
+    sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regRowid);
+    if( !old_col_mask ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, regRow);
+    }else{
+      sqlite3VdbeAddOp2(v, OP_RowData, iCur, regRow);
+    }
+    sqlite3VdbeAddOp3(v, OP_Insert, oldIdx, regRow, regRowid);
+
+    /* Generate the NEW table
+    */
+    if( chngRowid ){
+      sqlite3ExprCodeAndCache(pParse, pRowidExpr, regRowid);
+    }else{
+      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regRowid);
+    }
+    regCols = sqlite3GetTempRange(pParse, pTab->nCol);
+    for(i=0; i<pTab->nCol; i++){
+      if( i==pTab->iPKey ){
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regCols+i);
+        continue;
+      }
+      j = aXRef[i];
+      if( new_col_mask&((u32)1<<i) || new_col_mask==0xffffffff ){
+        if( j<0 ){
+          sqlite3VdbeAddOp3(v, OP_Column, iCur, i, regCols+i);
+          sqlite3ColumnDefault(v, pTab, i);
+        }else{
+          sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr, regCols+i);
+        }
+      }else{
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regCols+i);
+      }
+    }
+    sqlite3VdbeAddOp3(v, OP_MakeRecord, regCols, pTab->nCol, regRow);
+    if( !isView ){
+      sqlite3TableAffinityStr(v, pTab);
+      sqlite3ExprCacheAffinityChange(pParse, regCols, pTab->nCol);
+    }
+    sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol);
+    /* if( pParse->nErr ) goto update_cleanup; */
+    sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRow, regRowid);
+    sqlite3ReleaseTempReg(pParse, regRowid);
+    sqlite3ReleaseTempReg(pParse, regRow);
+
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger);
+    sqlite3VdbeJumpHere(v, iEndBeforeTrigger);
+  }
+
+  if( !isView && !IsVirtual(pTab) ){
+    /* Loop over every record that needs updating.  We have to load
+    ** the old data for each record to be updated because some columns
+    ** might not change and we will need to copy the old value.
+    ** Also, the old data is needed to delete the old index entries.
+    ** So make the cursor point at the old record.
+    */
+    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid);
+
+    /* If the record number will change, push the record number as it
+    ** will be after the update. (The old record number is currently
+    ** on top of the stack.)
+    */
+    if( chngRowid ){
+      sqlite3ExprCode(pParse, pRowidExpr, regNewRowid);
+      sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid);
+    }
+
+    /* Compute new data for this record.  
+    */
+    for(i=0; i<pTab->nCol; i++){
+      if( i==pTab->iPKey ){
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regData+i);
+        continue;
+      }
+      j = aXRef[i];
+      if( j<0 ){
+        sqlite3VdbeAddOp3(v, OP_Column, iCur, i, regData+i);
+        sqlite3ColumnDefault(v, pTab, i);
+      }else{
+        sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regData+i);
+      }
+    }
+
+    /* Do constraint checks
+    */
+    sqlite3GenerateConstraintChecks(pParse, pTab, iCur, regNewRowid,
+                                    aRegIdx, chngRowid, 1,
+                                    onError, addr);
+
+    /* Delete the old indices for the current record.
+    */
+    j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regOldRowid);
+    sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, aRegIdx);
+
+    /* If changing the record number, delete the old record.
+    */
+    if( chngRowid ){
+      sqlite3VdbeAddOp2(v, OP_Delete, iCur, 0);
+    }
+    sqlite3VdbeJumpHere(v, j1);
+
+    /* Create the new index entries and the new record.
+    */
+    sqlite3CompleteInsertion(pParse, pTab, iCur, regNewRowid, 
+                             aRegIdx, chngRowid, 1, -1, 0);
+  }
+
+  /* Increment the row counter 
+  */
+  if( db->flags & SQLITE_CountRows && !pParse->trigStack){
+    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
+  }
+
+  /* If there are triggers, close all the cursors after each iteration
+  ** through the loop.  The fire the after triggers.
+  */
+  if( triggers_exist ){
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger);
+    sqlite3VdbeJumpHere(v, iEndAfterTrigger);
+  }
+
+  /* Repeat the above with the next record to be updated, until
+  ** all record selected by the WHERE clause have been updated.
+  */
+  sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
+  sqlite3VdbeJumpHere(v, addr);
+
+  /* Close all tables */
+  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
+    if( openAll || aRegIdx[i]>0 ){
+      sqlite3VdbeAddOp2(v, OP_Close, iCur+i+1, 0);
+    }
+  }
+  sqlite3VdbeAddOp2(v, OP_Close, iCur, 0);
+  if( triggers_exist ){
+    sqlite3VdbeAddOp2(v, OP_Close, newIdx, 0);
+    sqlite3VdbeAddOp2(v, OP_Close, oldIdx, 0);
+  }
+
+  /*
+  ** Return the number of rows that were changed. If this routine is 
+  ** generating code because of a call to sqlite3NestedParse(), do not
+  ** invoke the callback function.
+  */
+  if( db->flags & SQLITE_CountRows && !pParse->trigStack && pParse->nested==0 ){
+    sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
+    sqlite3VdbeSetNumCols(v, 1);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", P4_STATIC);
+  }
+
+update_cleanup:
+  sqlite3AuthContextPop(&sContext);
+  sqlite3DbFree(db, aRegIdx);
+  sqlite3DbFree(db, aXRef);
+  sqlite3SrcListDelete(db, pTabList);
+  sqlite3ExprListDelete(db, pChanges);
+  sqlite3ExprDelete(db, pWhere);
+  return;
+}
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Generate code for an UPDATE of a virtual table.
+**
+** The strategy is that we create an ephemerial table that contains
+** for each row to be changed:
+**
+**   (A)  The original rowid of that row.
+**   (B)  The revised rowid for the row. (note1)
+**   (C)  The content of every column in the row.
+**
+** Then we loop over this ephemeral table and for each row in
+** the ephermeral table call VUpdate.
+**
+** When finished, drop the ephemeral table.
+**
+** (note1) Actually, if we know in advance that (A) is always the same
+** as (B) we only store (A), then duplicate (A) when pulling
+** it out of the ephemeral table before calling VUpdate.
+*/
+static void updateVirtualTable(
+  Parse *pParse,       /* The parsing context */
+  SrcList *pSrc,       /* The virtual table to be modified */
+  Table *pTab,         /* The virtual table */
+  ExprList *pChanges,  /* The columns to change in the UPDATE statement */
+  Expr *pRowid,        /* Expression used to recompute the rowid */
+  int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */
+  Expr *pWhere         /* WHERE clause of the UPDATE statement */
+){
+  Vdbe *v = pParse->pVdbe;  /* Virtual machine under construction */
+  ExprList *pEList = 0;     /* The result set of the SELECT statement */
+  Select *pSelect = 0;      /* The SELECT statement */
+  Expr *pExpr;              /* Temporary expression */
+  int ephemTab;             /* Table holding the result of the SELECT */
+  int i;                    /* Loop counter */
+  int addr;                 /* Address of top of loop */
+  int iReg;                 /* First register in set passed to OP_VUpdate */
+  sqlite3 *db = pParse->db; /* Database connection */
+  const char *pVtab = (const char*)pTab->pVtab;
+  SelectDest dest;
+
+  /* Construct the SELECT statement that will find the new values for
+  ** all updated rows. 
+  */
+  pEList = sqlite3ExprListAppend(pParse, 0, 
+                                 sqlite3CreateIdExpr(pParse, "_rowid_"), 0);
+  if( pRowid ){
+    pEList = sqlite3ExprListAppend(pParse, pEList,
+                                   sqlite3ExprDup(db, pRowid), 0);
+  }
+  assert( pTab->iPKey<0 );
+  for(i=0; i<pTab->nCol; i++){
+    if( aXRef[i]>=0 ){
+      pExpr = sqlite3ExprDup(db, pChanges->a[aXRef[i]].pExpr);
+    }else{
+      pExpr = sqlite3CreateIdExpr(pParse, pTab->aCol[i].zName);
+    }
+    pEList = sqlite3ExprListAppend(pParse, pEList, pExpr, 0);
+  }
+  pSelect = sqlite3SelectNew(pParse, pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0);
+  
+  /* Create the ephemeral table into which the update results will
+  ** be stored.
+  */
+  assert( v );
+  ephemTab = pParse->nTab++;
+  sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0));
+
+  /* fill the ephemeral table 
+  */
+  sqlite3SelectDestInit(&dest, SRT_Table, ephemTab);
+  sqlite3Select(pParse, pSelect, &dest, 0, 0, 0);
+
+  /* Generate code to scan the ephemeral table and call VUpdate. */
+  iReg = ++pParse->nMem;
+  pParse->nMem += pTab->nCol+1;
+  sqlite3VdbeAddOp2(v, OP_Rewind, ephemTab, 0);
+  addr = sqlite3VdbeCurrentAddr(v);
+  sqlite3VdbeAddOp3(v, OP_Column,  ephemTab, 0, iReg);
+  sqlite3VdbeAddOp3(v, OP_Column, ephemTab, (pRowid?1:0), iReg+1);
+  for(i=0; i<pTab->nCol; i++){
+    sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i+1+(pRowid!=0), iReg+2+i);
+  }
+  sqlite3VtabMakeWritable(pParse, pTab);
+  sqlite3VdbeAddOp4(v, OP_VUpdate, 0, pTab->nCol+2, iReg, pVtab, P4_VTAB);
+  sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr);
+  sqlite3VdbeJumpHere(v, addr-1);
+  sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
+
+  /* Cleanup */
+  sqlite3SelectDelete(db, pSelect);  
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/* Make sure "isView" gets undefined in case this file becomes part of
+** the amalgamation - so that subsequent files do not see isView as a
+** macro. */
+#undef isView
diff --git a/third_party/sqlite/src/utf.c b/third_party/sqlite/src/utf.c
new file mode 100755
index 0000000..8711a4c
--- /dev/null
+++ b/third_party/sqlite/src/utf.c
@@ -0,0 +1,530 @@
+/*
+** 2004 April 13
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains routines used to translate between UTF-8, 
+** UTF-16, UTF-16BE, and UTF-16LE.
+**
+** $Id: utf.c,v 1.63 2008/07/29 11:25:14 danielk1977 Exp $
+**
+** Notes on UTF-8:
+**
+**   Byte-0    Byte-1    Byte-2    Byte-3    Value
+**  0xxxxxxx                                 00000000 00000000 0xxxxxxx
+**  110yyyyy  10xxxxxx                       00000000 00000yyy yyxxxxxx
+**  1110zzzz  10yyyyyy  10xxxxxx             00000000 zzzzyyyy yyxxxxxx
+**  11110uuu  10uuzzzz  10yyyyyy  10xxxxxx   000uuuuu zzzzyyyy yyxxxxxx
+**
+**
+** Notes on UTF-16:  (with wwww+1==uuuuu)
+**
+**      Word-0               Word-1          Value
+**  110110ww wwzzzzyy   110111yy yyxxxxxx    000uuuuu zzzzyyyy yyxxxxxx
+**  zzzzyyyy yyxxxxxx                        00000000 zzzzyyyy yyxxxxxx
+**
+**
+** BOM or Byte Order Mark:
+**     0xff 0xfe   little-endian utf-16 follows
+**     0xfe 0xff   big-endian utf-16 follows
+**
+*/
+#include "sqliteInt.h"
+#include <assert.h>
+#include "vdbeInt.h"
+
+/*
+** The following constant value is used by the SQLITE_BIGENDIAN and
+** SQLITE_LITTLEENDIAN macros.
+*/
+const int sqlite3one = 1;
+
+/*
+** This lookup table is used to help decode the first byte of
+** a multi-byte UTF8 character.
+*/
+static const unsigned char sqlite3UtfTrans1[] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+  0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
+};
+
+
+#define WRITE_UTF8(zOut, c) {                          \
+  if( c<0x00080 ){                                     \
+    *zOut++ = (c&0xFF);                                \
+  }                                                    \
+  else if( c<0x00800 ){                                \
+    *zOut++ = 0xC0 + ((c>>6)&0x1F);                    \
+    *zOut++ = 0x80 + (c & 0x3F);                       \
+  }                                                    \
+  else if( c<0x10000 ){                                \
+    *zOut++ = 0xE0 + ((c>>12)&0x0F);                   \
+    *zOut++ = 0x80 + ((c>>6) & 0x3F);                  \
+    *zOut++ = 0x80 + (c & 0x3F);                       \
+  }else{                                               \
+    *zOut++ = 0xF0 + ((c>>18) & 0x07);                 \
+    *zOut++ = 0x80 + ((c>>12) & 0x3F);                 \
+    *zOut++ = 0x80 + ((c>>6) & 0x3F);                  \
+    *zOut++ = 0x80 + (c & 0x3F);                       \
+  }                                                    \
+}
+
+#define WRITE_UTF16LE(zOut, c) {                                \
+  if( c<=0xFFFF ){                                              \
+    *zOut++ = (c&0x00FF);                                       \
+    *zOut++ = ((c>>8)&0x00FF);                                  \
+  }else{                                                        \
+    *zOut++ = (((c>>10)&0x003F) + (((c-0x10000)>>10)&0x00C0));  \
+    *zOut++ = (0x00D8 + (((c-0x10000)>>18)&0x03));              \
+    *zOut++ = (c&0x00FF);                                       \
+    *zOut++ = (0x00DC + ((c>>8)&0x03));                         \
+  }                                                             \
+}
+
+#define WRITE_UTF16BE(zOut, c) {                                \
+  if( c<=0xFFFF ){                                              \
+    *zOut++ = ((c>>8)&0x00FF);                                  \
+    *zOut++ = (c&0x00FF);                                       \
+  }else{                                                        \
+    *zOut++ = (0x00D8 + (((c-0x10000)>>18)&0x03));              \
+    *zOut++ = (((c>>10)&0x003F) + (((c-0x10000)>>10)&0x00C0));  \
+    *zOut++ = (0x00DC + ((c>>8)&0x03));                         \
+    *zOut++ = (c&0x00FF);                                       \
+  }                                                             \
+}
+
+#define READ_UTF16LE(zIn, c){                                         \
+  c = (*zIn++);                                                       \
+  c += ((*zIn++)<<8);                                                 \
+  if( c>=0xD800 && c<0xE000 ){                                       \
+    int c2 = (*zIn++);                                                \
+    c2 += ((*zIn++)<<8);                                              \
+    c = (c2&0x03FF) + ((c&0x003F)<<10) + (((c&0x03C0)+0x0040)<<10);   \
+    if( (c & 0xFFFF0000)==0 ) c = 0xFFFD;                             \
+  }                                                                   \
+}
+
+#define READ_UTF16BE(zIn, c){                                         \
+  c = ((*zIn++)<<8);                                                  \
+  c += (*zIn++);                                                      \
+  if( c>=0xD800 && c<0xE000 ){                                       \
+    int c2 = ((*zIn++)<<8);                                           \
+    c2 += (*zIn++);                                                   \
+    c = (c2&0x03FF) + ((c&0x003F)<<10) + (((c&0x03C0)+0x0040)<<10);   \
+    if( (c & 0xFFFF0000)==0 ) c = 0xFFFD;                             \
+  }                                                                   \
+}
+
+/*
+** Translate a single UTF-8 character.  Return the unicode value.
+**
+** During translation, assume that the byte that zTerm points
+** is a 0x00.
+**
+** Write a pointer to the next unread byte back into *pzNext.
+**
+** Notes On Invalid UTF-8:
+**
+**  *  This routine never allows a 7-bit character (0x00 through 0x7f) to
+**     be encoded as a multi-byte character.  Any multi-byte character that
+**     attempts to encode a value between 0x00 and 0x7f is rendered as 0xfffd.
+**
+**  *  This routine never allows a UTF16 surrogate value to be encoded.
+**     If a multi-byte character attempts to encode a value between
+**     0xd800 and 0xe000 then it is rendered as 0xfffd.
+**
+**  *  Bytes in the range of 0x80 through 0xbf which occur as the first
+**     byte of a character are interpreted as single-byte characters
+**     and rendered as themselves even though they are technically
+**     invalid characters.
+**
+**  *  This routine accepts an infinite number of different UTF8 encodings
+**     for unicode values 0x80 and greater.  It do not change over-length
+**     encodings to 0xfffd as some systems recommend.
+*/
+#define READ_UTF8(zIn, zTerm, c)                           \
+  c = *(zIn++);                                            \
+  if( c>=0xc0 ){                                           \
+    c = sqlite3UtfTrans1[c-0xc0];                          \
+    while( zIn!=zTerm && (*zIn & 0xc0)==0x80 ){            \
+      c = (c<<6) + (0x3f & *(zIn++));                      \
+    }                                                      \
+    if( c<0x80                                             \
+        || (c&0xFFFFF800)==0xD800                          \
+        || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }        \
+  }
+int sqlite3Utf8Read(
+  const unsigned char *z,         /* First byte of UTF-8 character */
+  const unsigned char *zTerm,     /* Pretend this byte is 0x00 */
+  const unsigned char **pzNext    /* Write first byte past UTF-8 char here */
+){
+  int c;
+  READ_UTF8(z, zTerm, c);
+  *pzNext = z;
+  return c;
+}
+
+
+
+
+/*
+** If the TRANSLATE_TRACE macro is defined, the value of each Mem is
+** printed on stderr on the way into and out of sqlite3VdbeMemTranslate().
+*/ 
+/* #define TRANSLATE_TRACE 1 */
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** This routine transforms the internal text encoding used by pMem to
+** desiredEnc. It is an error if the string is already of the desired
+** encoding, or if *pMem does not contain a string value.
+*/
+int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
+  int len;                    /* Maximum length of output string in bytes */
+  unsigned char *zOut;                  /* Output buffer */
+  unsigned char *zIn;                   /* Input iterator */
+  unsigned char *zTerm;                 /* End of input */
+  unsigned char *z;                     /* Output iterator */
+  unsigned int c;
+
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  assert( pMem->flags&MEM_Str );
+  assert( pMem->enc!=desiredEnc );
+  assert( pMem->enc!=0 );
+  assert( pMem->n>=0 );
+
+#if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
+  {
+    char zBuf[100];
+    sqlite3VdbeMemPrettyPrint(pMem, zBuf);
+    fprintf(stderr, "INPUT:  %s\n", zBuf);
+  }
+#endif
+
+  /* If the translation is between UTF-16 little and big endian, then 
+  ** all that is required is to swap the byte order. This case is handled
+  ** differently from the others.
+  */
+  if( pMem->enc!=SQLITE_UTF8 && desiredEnc!=SQLITE_UTF8 ){
+    u8 temp;
+    int rc;
+    rc = sqlite3VdbeMemMakeWriteable(pMem);
+    if( rc!=SQLITE_OK ){
+      assert( rc==SQLITE_NOMEM );
+      return SQLITE_NOMEM;
+    }
+    zIn = (u8*)pMem->z;
+    zTerm = &zIn[pMem->n];
+    while( zIn<zTerm ){
+      temp = *zIn;
+      *zIn = *(zIn+1);
+      zIn++;
+      *zIn++ = temp;
+    }
+    pMem->enc = desiredEnc;
+    goto translate_out;
+  }
+
+  /* Set len to the maximum number of bytes required in the output buffer. */
+  if( desiredEnc==SQLITE_UTF8 ){
+    /* When converting from UTF-16, the maximum growth results from
+    ** translating a 2-byte character to a 4-byte UTF-8 character.
+    ** A single byte is required for the output string
+    ** nul-terminator.
+    */
+    len = pMem->n * 2 + 1;
+  }else{
+    /* When converting from UTF-8 to UTF-16 the maximum growth is caused
+    ** when a 1-byte UTF-8 character is translated into a 2-byte UTF-16
+    ** character. Two bytes are required in the output buffer for the
+    ** nul-terminator.
+    */
+    len = pMem->n * 2 + 2;
+  }
+
+  /* Set zIn to point at the start of the input buffer and zTerm to point 1
+  ** byte past the end.
+  **
+  ** Variable zOut is set to point at the output buffer, space obtained
+  ** from sqlite3_malloc().
+  */
+  zIn = (u8*)pMem->z;
+  zTerm = &zIn[pMem->n];
+  zOut = sqlite3DbMallocRaw(pMem->db, len);
+  if( !zOut ){
+    return SQLITE_NOMEM;
+  }
+  z = zOut;
+
+  if( pMem->enc==SQLITE_UTF8 ){
+    if( desiredEnc==SQLITE_UTF16LE ){
+      /* UTF-8 -> UTF-16 Little-endian */
+      while( zIn<zTerm ){
+        /* c = sqlite3Utf8Read(zIn, zTerm, (const u8**)&zIn); */
+        READ_UTF8(zIn, zTerm, c);
+        WRITE_UTF16LE(z, c);
+      }
+    }else{
+      assert( desiredEnc==SQLITE_UTF16BE );
+      /* UTF-8 -> UTF-16 Big-endian */
+      while( zIn<zTerm ){
+        /* c = sqlite3Utf8Read(zIn, zTerm, (const u8**)&zIn); */
+        READ_UTF8(zIn, zTerm, c);
+        WRITE_UTF16BE(z, c);
+      }
+    }
+    pMem->n = z - zOut;
+    *z++ = 0;
+  }else{
+    assert( desiredEnc==SQLITE_UTF8 );
+    if( pMem->enc==SQLITE_UTF16LE ){
+      /* UTF-16 Little-endian -> UTF-8 */
+      while( zIn<zTerm ){
+        READ_UTF16LE(zIn, c); 
+        WRITE_UTF8(z, c);
+      }
+    }else{
+      /* UTF-16 Big-endian -> UTF-8 */
+      while( zIn<zTerm ){
+        READ_UTF16BE(zIn, c); 
+        WRITE_UTF8(z, c);
+      }
+    }
+    pMem->n = z - zOut;
+  }
+  *z = 0;
+  assert( (pMem->n+(desiredEnc==SQLITE_UTF8?1:2))<=len );
+
+  sqlite3VdbeMemRelease(pMem);
+  pMem->flags &= ~(MEM_Static|MEM_Dyn|MEM_Ephem);
+  pMem->enc = desiredEnc;
+  pMem->flags |= (MEM_Term|MEM_Dyn);
+  pMem->z = (char*)zOut;
+  pMem->zMalloc = pMem->z;
+
+translate_out:
+#if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
+  {
+    char zBuf[100];
+    sqlite3VdbeMemPrettyPrint(pMem, zBuf);
+    fprintf(stderr, "OUTPUT: %s\n", zBuf);
+  }
+#endif
+  return SQLITE_OK;
+}
+
+/*
+** This routine checks for a byte-order mark at the beginning of the 
+** UTF-16 string stored in *pMem. If one is present, it is removed and
+** the encoding of the Mem adjusted. This routine does not do any
+** byte-swapping, it just sets Mem.enc appropriately.
+**
+** The allocation (static, dynamic etc.) and encoding of the Mem may be
+** changed by this function.
+*/
+int sqlite3VdbeMemHandleBom(Mem *pMem){
+  int rc = SQLITE_OK;
+  u8 bom = 0;
+
+  if( pMem->n<0 || pMem->n>1 ){
+    u8 b1 = *(u8 *)pMem->z;
+    u8 b2 = *(((u8 *)pMem->z) + 1);
+    if( b1==0xFE && b2==0xFF ){
+      bom = SQLITE_UTF16BE;
+    }
+    if( b1==0xFF && b2==0xFE ){
+      bom = SQLITE_UTF16LE;
+    }
+  }
+  
+  if( bom ){
+    rc = sqlite3VdbeMemMakeWriteable(pMem);
+    if( rc==SQLITE_OK ){
+      pMem->n -= 2;
+      memmove(pMem->z, &pMem->z[2], pMem->n);
+      pMem->z[pMem->n] = '\0';
+      pMem->z[pMem->n+1] = '\0';
+      pMem->flags |= MEM_Term;
+      pMem->enc = bom;
+    }
+  }
+  return rc;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+/*
+** pZ is a UTF-8 encoded unicode string. If nByte is less than zero,
+** return the number of unicode characters in pZ up to (but not including)
+** the first 0x00 byte. If nByte is not less than zero, return the
+** number of unicode characters in the first nByte of pZ (or up to 
+** the first 0x00, whichever comes first).
+*/
+int sqlite3Utf8CharLen(const char *zIn, int nByte){
+  int r = 0;
+  const u8 *z = (const u8*)zIn;
+  const u8 *zTerm;
+  if( nByte>=0 ){
+    zTerm = &z[nByte];
+  }else{
+    zTerm = (const u8*)(-1);
+  }
+  assert( z<=zTerm );
+  while( *z!=0 && z<zTerm ){
+    SQLITE_SKIP_UTF8(z);
+    r++;
+  }
+  return r;
+}
+
+/* This test function is not currently used by the automated test-suite. 
+** Hence it is only available in debug builds.
+*/
+#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
+/*
+** Translate UTF-8 to UTF-8.
+**
+** This has the effect of making sure that the string is well-formed
+** UTF-8.  Miscoded characters are removed.
+**
+** The translation is done in-place (since it is impossible for the
+** correct UTF-8 encoding to be longer than a malformed encoding).
+*/
+int sqlite3Utf8To8(unsigned char *zIn){
+  unsigned char *zOut = zIn;
+  unsigned char *zStart = zIn;
+  unsigned char *zTerm;
+  u32 c;
+
+  while( zIn[0] ){
+    c = sqlite3Utf8Read(zIn, zTerm, (const u8**)&zIn);
+    if( c!=0xfffd ){
+      WRITE_UTF8(zOut, c);
+    }
+  }
+  *zOut = 0;
+  return zOut - zStart;
+}
+#endif
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Convert a UTF-16 string in the native encoding into a UTF-8 string.
+** Memory to hold the UTF-8 string is obtained from sqlite3_malloc and must
+** be freed by the calling function.
+**
+** NULL is returned if there is an allocation error.
+*/
+char *sqlite3Utf16to8(sqlite3 *db, const void *z, int nByte){
+  Mem m;
+  memset(&m, 0, sizeof(m));
+  m.db = db;
+  sqlite3VdbeMemSetStr(&m, z, nByte, SQLITE_UTF16NATIVE, SQLITE_STATIC);
+  sqlite3VdbeChangeEncoding(&m, SQLITE_UTF8);
+  if( db->mallocFailed ){
+    sqlite3VdbeMemRelease(&m);
+    m.z = 0;
+  }
+  assert( (m.flags & MEM_Term)!=0 || db->mallocFailed );
+  assert( (m.flags & MEM_Str)!=0 || db->mallocFailed );
+  return (m.flags & MEM_Dyn)!=0 ? m.z : sqlite3DbStrDup(db, m.z);
+}
+
+/*
+** pZ is a UTF-16 encoded unicode string. If nChar is less than zero,
+** return the number of bytes up to (but not including), the first pair
+** of consecutive 0x00 bytes in pZ. If nChar is not less than zero,
+** then return the number of bytes in the first nChar unicode characters
+** in pZ (or up until the first pair of 0x00 bytes, whichever comes first).
+*/
+int sqlite3Utf16ByteLen(const void *zIn, int nChar){
+  unsigned int c = 1;
+  char const *z = zIn;
+  int n = 0;
+  if( SQLITE_UTF16NATIVE==SQLITE_UTF16BE ){
+    /* Using an "if (SQLITE_UTF16NATIVE==SQLITE_UTF16BE)" construct here
+    ** and in other parts of this file means that at one branch will
+    ** not be covered by coverage testing on any single host. But coverage
+    ** will be complete if the tests are run on both a little-endian and 
+    ** big-endian host. Because both the UTF16NATIVE and SQLITE_UTF16BE
+    ** macros are constant at compile time the compiler can determine
+    ** which branch will be followed. It is therefore assumed that no runtime
+    ** penalty is paid for this "if" statement.
+    */
+    while( c && ((nChar<0) || n<nChar) ){
+      READ_UTF16BE(z, c);
+      n++;
+    }
+  }else{
+    while( c && ((nChar<0) || n<nChar) ){
+      READ_UTF16LE(z, c);
+      n++;
+    }
+  }
+  return (z-(char const *)zIn)-((c==0)?2:0);
+}
+
+#if defined(SQLITE_TEST)
+/*
+** This routine is called from the TCL test function "translate_selftest".
+** It checks that the primitives for serializing and deserializing
+** characters in each encoding are inverses of each other.
+*/
+void sqlite3UtfSelfTest(){
+  unsigned int i, t;
+  unsigned char zBuf[20];
+  unsigned char *z;
+  unsigned char *zTerm;
+  int n;
+  unsigned int c;
+
+  for(i=0; i<0x00110000; i++){
+    z = zBuf;
+    WRITE_UTF8(z, i);
+    n = z-zBuf;
+    z[0] = 0;
+    zTerm = z;
+    z = zBuf;
+    c = sqlite3Utf8Read(z, zTerm, (const u8**)&z);
+    t = i;
+    if( i>=0xD800 && i<=0xDFFF ) t = 0xFFFD;
+    if( (i&0xFFFFFFFE)==0xFFFE ) t = 0xFFFD;
+    assert( c==t );
+    assert( (z-zBuf)==n );
+  }
+  for(i=0; i<0x00110000; i++){
+    if( i>=0xD800 && i<0xE000 ) continue;
+    z = zBuf;
+    WRITE_UTF16LE(z, i);
+    n = z-zBuf;
+    z[0] = 0;
+    z = zBuf;
+    READ_UTF16LE(z, c);
+    assert( c==i );
+    assert( (z-zBuf)==n );
+  }
+  for(i=0; i<0x00110000; i++){
+    if( i>=0xD800 && i<0xE000 ) continue;
+    z = zBuf;
+    WRITE_UTF16BE(z, i);
+    n = z-zBuf;
+    z[0] = 0;
+    z = zBuf;
+    READ_UTF16BE(z, c);
+    assert( c==i );
+    assert( (z-zBuf)==n );
+  }
+}
+#endif /* SQLITE_TEST */
+#endif /* SQLITE_OMIT_UTF16 */
diff --git a/third_party/sqlite/src/util.c b/third_party/sqlite/src/util.c
new file mode 100755
index 0000000..919452c
--- /dev/null
+++ b/third_party/sqlite/src/util.c
@@ -0,0 +1,952 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Utility functions used throughout sqlite.
+**
+** This file contains functions for allocating memory, comparing
+** strings, and stuff like that.
+**
+** $Id: util.c,v 1.241 2008/07/28 19:34:54 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <stdarg.h>
+#include <ctype.h>
+
+
+/*
+** Return true if the floating point value is Not a Number (NaN).
+*/
+int sqlite3IsNaN(double x){
+  /* This NaN test sometimes fails if compiled on GCC with -ffast-math.
+  ** On the other hand, the use of -ffast-math comes with the following
+  ** warning:
+  **
+  **      This option [-ffast-math] should never be turned on by any
+  **      -O option since it can result in incorrect output for programs
+  **      which depend on an exact implementation of IEEE or ISO 
+  **      rules/specifications for math functions.
+  **
+  ** Under MSVC, this NaN test may fail if compiled with a floating-
+  ** point precision mode other than /fp:precise.  From the MSDN 
+  ** documentation:
+  **
+  **      The compiler [with /fp:precise] will properly handle comparisons 
+  **      involving NaN. For example, x != x evaluates to true if x is NaN 
+  **      ...
+  */
+#ifdef __FAST_MATH__
+# error SQLite will not work correctly with the -ffast-math option of GCC.
+#endif
+  volatile double y = x;
+  volatile double z = y;
+  return y!=z;
+}
+
+/*
+** Return the length of a string, except do not allow the string length
+** to exceed the SQLITE_LIMIT_LENGTH setting.
+*/
+int sqlite3Strlen(sqlite3 *db, const char *z){
+  const char *z2 = z;
+  int len;
+  size_t x;
+  while( *z2 ){ z2++; }
+  x = z2 - z;
+  len = 0x7fffffff & x;
+  if( len!=x || len > db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    return db->aLimit[SQLITE_LIMIT_LENGTH];
+  }else{
+    return len;
+  }
+}
+
+/*
+** Set the most recent error code and error string for the sqlite
+** handle "db". The error code is set to "err_code".
+**
+** If it is not NULL, string zFormat specifies the format of the
+** error string in the style of the printf functions: The following
+** format characters are allowed:
+**
+**      %s      Insert a string
+**      %z      A string that should be freed after use
+**      %d      Insert an integer
+**      %T      Insert a token
+**      %S      Insert the first element of a SrcList
+**
+** zFormat and any string tokens that follow it are assumed to be
+** encoded in UTF-8.
+**
+** To clear the most recent error for sqlite handle "db", sqlite3Error
+** should be called with err_code set to SQLITE_OK and zFormat set
+** to NULL.
+*/
+void sqlite3Error(sqlite3 *db, int err_code, const char *zFormat, ...){
+  if( db && (db->pErr || (db->pErr = sqlite3ValueNew(db))!=0) ){
+    db->errCode = err_code;
+    if( zFormat ){
+      char *z;
+      va_list ap;
+      va_start(ap, zFormat);
+      z = sqlite3VMPrintf(db, zFormat, ap);
+      va_end(ap);
+      sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, SQLITE_DYNAMIC);
+    }else{
+      sqlite3ValueSetStr(db->pErr, 0, 0, SQLITE_UTF8, SQLITE_STATIC);
+    }
+  }
+}
+
+/*
+** Add an error message to pParse->zErrMsg and increment pParse->nErr.
+** The following formatting characters are allowed:
+**
+**      %s      Insert a string
+**      %z      A string that should be freed after use
+**      %d      Insert an integer
+**      %T      Insert a token
+**      %S      Insert the first element of a SrcList
+**
+** This function should be used to report any error that occurs whilst
+** compiling an SQL statement (i.e. within sqlite3_prepare()). The
+** last thing the sqlite3_prepare() function does is copy the error
+** stored by this function into the database handle using sqlite3Error().
+** Function sqlite3Error() should be used during statement execution
+** (sqlite3_step() etc.).
+*/
+void sqlite3ErrorMsg(Parse *pParse, const char *zFormat, ...){
+  va_list ap;
+  sqlite3 *db = pParse->db;
+  pParse->nErr++;
+  sqlite3DbFree(db, pParse->zErrMsg);
+  va_start(ap, zFormat);
+  pParse->zErrMsg = sqlite3VMPrintf(db, zFormat, ap);
+  va_end(ap);
+  if( pParse->rc==SQLITE_OK ){
+    pParse->rc = SQLITE_ERROR;
+  }
+}
+
+/*
+** Clear the error message in pParse, if any
+*/
+void sqlite3ErrorClear(Parse *pParse){
+  sqlite3DbFree(pParse->db, pParse->zErrMsg);
+  pParse->zErrMsg = 0;
+  pParse->nErr = 0;
+}
+
+/*
+** Convert an SQL-style quoted string into a normal string by removing
+** the quote characters.  The conversion is done in-place.  If the
+** input does not begin with a quote character, then this routine
+** is a no-op.
+**
+** 2002-Feb-14: This routine is extended to remove MS-Access style
+** brackets from around identifers.  For example:  "[a-b-c]" becomes
+** "a-b-c".
+*/
+void sqlite3Dequote(char *z){
+  int quote;
+  int i, j;
+  if( z==0 ) return;
+  quote = z[0];
+  switch( quote ){
+    case '\'':  break;
+    case '"':   break;
+    case '`':   break;                /* For MySQL compatibility */
+    case '[':   quote = ']';  break;  /* For MS SqlServer compatibility */
+    default:    return;
+  }
+  for(i=1, j=0; z[i]; i++){
+    if( z[i]==quote ){
+      if( z[i+1]==quote ){
+        z[j++] = quote;
+        i++;
+      }else{
+        z[j++] = 0;
+        break;
+      }
+    }else{
+      z[j++] = z[i];
+    }
+  }
+}
+
+/* Convenient short-hand */
+#define UpperToLower sqlite3UpperToLower
+
+/*
+** Some systems have stricmp().  Others have strcasecmp().  Because
+** there is no consistency, we will define our own.
+*/
+int sqlite3StrICmp(const char *zLeft, const char *zRight){
+  register unsigned char *a, *b;
+  a = (unsigned char *)zLeft;
+  b = (unsigned char *)zRight;
+  while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
+  return UpperToLower[*a] - UpperToLower[*b];
+}
+int sqlite3StrNICmp(const char *zLeft, const char *zRight, int N){
+  register unsigned char *a, *b;
+  a = (unsigned char *)zLeft;
+  b = (unsigned char *)zRight;
+  while( N-- > 0 && *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
+  return N<0 ? 0 : UpperToLower[*a] - UpperToLower[*b];
+}
+
+/*
+** Return TRUE if z is a pure numeric string.  Return FALSE if the
+** string contains any character which is not part of a number. If
+** the string is numeric and contains the '.' character, set *realnum
+** to TRUE (otherwise FALSE).
+**
+** An empty string is considered non-numeric.
+*/
+int sqlite3IsNumber(const char *z, int *realnum, u8 enc){
+  int incr = (enc==SQLITE_UTF8?1:2);
+  if( enc==SQLITE_UTF16BE ) z++;
+  if( *z=='-' || *z=='+' ) z += incr;
+  if( !isdigit(*(u8*)z) ){
+    return 0;
+  }
+  z += incr;
+  if( realnum ) *realnum = 0;
+  while( isdigit(*(u8*)z) ){ z += incr; }
+  if( *z=='.' ){
+    z += incr;
+    if( !isdigit(*(u8*)z) ) return 0;
+    while( isdigit(*(u8*)z) ){ z += incr; }
+    if( realnum ) *realnum = 1;
+  }
+  if( *z=='e' || *z=='E' ){
+    z += incr;
+    if( *z=='+' || *z=='-' ) z += incr;
+    if( !isdigit(*(u8*)z) ) return 0;
+    while( isdigit(*(u8*)z) ){ z += incr; }
+    if( realnum ) *realnum = 1;
+  }
+  return *z==0;
+}
+
+/*
+** The string z[] is an ascii representation of a real number.
+** Convert this string to a double.
+**
+** This routine assumes that z[] really is a valid number.  If it
+** is not, the result is undefined.
+**
+** This routine is used instead of the library atof() function because
+** the library atof() might want to use "," as the decimal point instead
+** of "." depending on how locale is set.  But that would cause problems
+** for SQL.  So this routine always uses "." regardless of locale.
+*/
+int sqlite3AtoF(const char *z, double *pResult){
+#ifndef SQLITE_OMIT_FLOATING_POINT
+  int sign = 1;
+  const char *zBegin = z;
+  LONGDOUBLE_TYPE v1 = 0.0;
+  int nSignificant = 0;
+  while( isspace(*(u8*)z) ) z++;
+  if( *z=='-' ){
+    sign = -1;
+    z++;
+  }else if( *z=='+' ){
+    z++;
+  }
+  while( z[0]=='0' ){
+    z++;
+  }
+  while( isdigit(*(u8*)z) ){
+    v1 = v1*10.0 + (*z - '0');
+    z++;
+    nSignificant++;
+  }
+  if( *z=='.' ){
+    LONGDOUBLE_TYPE divisor = 1.0;
+    z++;
+    if( nSignificant==0 ){
+      while( z[0]=='0' ){
+        divisor *= 10.0;
+        z++;
+      }
+    }
+    while( isdigit(*(u8*)z) ){
+      if( nSignificant<18 ){
+        v1 = v1*10.0 + (*z - '0');
+        divisor *= 10.0;
+        nSignificant++;
+      }
+      z++;
+    }
+    v1 /= divisor;
+  }
+  if( *z=='e' || *z=='E' ){
+    int esign = 1;
+    int eval = 0;
+    LONGDOUBLE_TYPE scale = 1.0;
+    z++;
+    if( *z=='-' ){
+      esign = -1;
+      z++;
+    }else if( *z=='+' ){
+      z++;
+    }
+    while( isdigit(*(u8*)z) ){
+      eval = eval*10 + *z - '0';
+      z++;
+    }
+    while( eval>=64 ){ scale *= 1.0e+64; eval -= 64; }
+    while( eval>=16 ){ scale *= 1.0e+16; eval -= 16; }
+    while( eval>=4 ){ scale *= 1.0e+4; eval -= 4; }
+    while( eval>=1 ){ scale *= 1.0e+1; eval -= 1; }
+    if( esign<0 ){
+      v1 /= scale;
+    }else{
+      v1 *= scale;
+    }
+  }
+  *pResult = sign<0 ? -v1 : v1;
+  return z - zBegin;
+#else
+  return sqlite3Atoi64(z, pResult);
+#endif /* SQLITE_OMIT_FLOATING_POINT */
+}
+
+/*
+** Compare the 19-character string zNum against the text representation
+** value 2^63:  9223372036854775808.  Return negative, zero, or positive
+** if zNum is less than, equal to, or greater than the string.
+**
+** Unlike memcmp() this routine is guaranteed to return the difference
+** in the values of the last digit if the only difference is in the
+** last digit.  So, for example,
+**
+**      compare2pow63("9223372036854775800")
+**
+** will return -8.
+*/
+static int compare2pow63(const char *zNum){
+  int c;
+  c = memcmp(zNum,"922337203685477580",18);
+  if( c==0 ){
+    c = zNum[18] - '8';
+  }
+  return c;
+}
+
+
+/*
+** Return TRUE if zNum is a 64-bit signed integer and write
+** the value of the integer into *pNum.  If zNum is not an integer
+** or is an integer that is too large to be expressed with 64 bits,
+** then return false.
+**
+** When this routine was originally written it dealt with only
+** 32-bit numbers.  At that time, it was much faster than the
+** atoi() library routine in RedHat 7.2.
+*/
+int sqlite3Atoi64(const char *zNum, i64 *pNum){
+  i64 v = 0;
+  int neg;
+  int i, c;
+  const char *zStart;
+  while( isspace(*(u8*)zNum) ) zNum++;
+  if( *zNum=='-' ){
+    neg = 1;
+    zNum++;
+  }else if( *zNum=='+' ){
+    neg = 0;
+    zNum++;
+  }else{
+    neg = 0;
+  }
+  zStart = zNum;
+  while( zNum[0]=='0' ){ zNum++; } /* Skip over leading zeros. Ticket #2454 */
+  for(i=0; (c=zNum[i])>='0' && c<='9'; i++){
+    v = v*10 + c - '0';
+  }
+  *pNum = neg ? -v : v;
+  if( c!=0 || (i==0 && zStart==zNum) || i>19 ){
+    /* zNum is empty or contains non-numeric text or is longer
+    ** than 19 digits (thus guaranting that it is too large) */
+    return 0;
+  }else if( i<19 ){
+    /* Less than 19 digits, so we know that it fits in 64 bits */
+    return 1;
+  }else{
+    /* 19-digit numbers must be no larger than 9223372036854775807 if positive
+    ** or 9223372036854775808 if negative.  Note that 9223372036854665808
+    ** is 2^63. */
+    return compare2pow63(zNum)<neg;
+  }
+}
+
+/*
+** The string zNum represents an integer.  There might be some other
+** information following the integer too, but that part is ignored.
+** If the integer that the prefix of zNum represents will fit in a
+** 64-bit signed integer, return TRUE.  Otherwise return FALSE.
+**
+** This routine returns FALSE for the string -9223372036854775808 even that
+** that number will, in theory fit in a 64-bit integer.  Positive
+** 9223373036854775808 will not fit in 64 bits.  So it seems safer to return
+** false.
+*/
+int sqlite3FitsIn64Bits(const char *zNum, int negFlag){
+  int i, c;
+  int neg = 0;
+  if( *zNum=='-' ){
+    neg = 1;
+    zNum++;
+  }else if( *zNum=='+' ){
+    zNum++;
+  }
+  if( negFlag ) neg = 1-neg;
+  while( *zNum=='0' ){
+    zNum++;   /* Skip leading zeros.  Ticket #2454 */
+  }
+  for(i=0; (c=zNum[i])>='0' && c<='9'; i++){}
+  if( i<19 ){
+    /* Guaranteed to fit if less than 19 digits */
+    return 1;
+  }else if( i>19 ){
+    /* Guaranteed to be too big if greater than 19 digits */
+    return 0;
+  }else{
+    /* Compare against 2^63. */
+    return compare2pow63(zNum)<neg;
+  }
+}
+
+/*
+** If zNum represents an integer that will fit in 32-bits, then set
+** *pValue to that integer and return true.  Otherwise return false.
+**
+** Any non-numeric characters that following zNum are ignored.
+** This is different from sqlite3Atoi64() which requires the
+** input number to be zero-terminated.
+*/
+int sqlite3GetInt32(const char *zNum, int *pValue){
+  sqlite_int64 v = 0;
+  int i, c;
+  int neg = 0;
+  if( zNum[0]=='-' ){
+    neg = 1;
+    zNum++;
+  }else if( zNum[0]=='+' ){
+    zNum++;
+  }
+  while( zNum[0]=='0' ) zNum++;
+  for(i=0; i<11 && (c = zNum[i] - '0')>=0 && c<=9; i++){
+    v = v*10 + c;
+  }
+
+  /* The longest decimal representation of a 32 bit integer is 10 digits:
+  **
+  **             1234567890
+  **     2^31 -> 2147483648
+  */
+  if( i>10 ){
+    return 0;
+  }
+  if( v-neg>2147483647 ){
+    return 0;
+  }
+  if( neg ){
+    v = -v;
+  }
+  *pValue = (int)v;
+  return 1;
+}
+
+/*
+** The variable-length integer encoding is as follows:
+**
+** KEY:
+**         A = 0xxxxxxx    7 bits of data and one flag bit
+**         B = 1xxxxxxx    7 bits of data and one flag bit
+**         C = xxxxxxxx    8 bits of data
+**
+**  7 bits - A
+** 14 bits - BA
+** 21 bits - BBA
+** 28 bits - BBBA
+** 35 bits - BBBBA
+** 42 bits - BBBBBA
+** 49 bits - BBBBBBA
+** 56 bits - BBBBBBBA
+** 64 bits - BBBBBBBBC
+*/
+
+/*
+** Write a 64-bit variable-length integer to memory starting at p[0].
+** The length of data write will be between 1 and 9 bytes.  The number
+** of bytes written is returned.
+**
+** A variable-length integer consists of the lower 7 bits of each byte
+** for all bytes that have the 8th bit set and one byte with the 8th
+** bit clear.  Except, if we get to the 9th byte, it stores the full
+** 8 bits and is the last byte.
+*/
+int sqlite3PutVarint(unsigned char *p, u64 v){
+  int i, j, n;
+  u8 buf[10];
+  if( v & (((u64)0xff000000)<<32) ){
+    p[8] = v;
+    v >>= 8;
+    for(i=7; i>=0; i--){
+      p[i] = (v & 0x7f) | 0x80;
+      v >>= 7;
+    }
+    return 9;
+  }    
+  n = 0;
+  do{
+    buf[n++] = (v & 0x7f) | 0x80;
+    v >>= 7;
+  }while( v!=0 );
+  buf[0] &= 0x7f;
+  assert( n<=9 );
+  for(i=0, j=n-1; j>=0; j--, i++){
+    p[i] = buf[j];
+  }
+  return n;
+}
+
+/*
+** This routine is a faster version of sqlite3PutVarint() that only
+** works for 32-bit positive integers and which is optimized for
+** the common case of small integers.  A MACRO version, putVarint32,
+** is provided which inlines the single-byte case.  All code should use
+** the MACRO version as this function assumes the single-byte case has
+** already been handled.
+*/
+int sqlite3PutVarint32(unsigned char *p, u32 v){
+#ifndef putVarint32
+  if( (v & ~0x7f)==0 ){
+    p[0] = v;
+    return 1;
+  }
+#endif
+  if( (v & ~0x3fff)==0 ){
+    p[0] = (v>>7) | 0x80;
+    p[1] = v & 0x7f;
+    return 2;
+  }
+  return sqlite3PutVarint(p, v);
+}
+
+/*
+** Read a 64-bit variable-length integer from memory starting at p[0].
+** Return the number of bytes read.  The value is stored in *v.
+*/
+int sqlite3GetVarint(const unsigned char *p, u64 *v){
+  u32 a,b,s;
+
+  a = *p;
+  /* a: p0 (unmasked) */
+  if (!(a&0x80))
+  {
+    *v = a;
+    return 1;
+  }
+
+  p++;
+  b = *p;
+  /* b: p1 (unmasked) */
+  if (!(b&0x80))
+  {
+    a &= 0x7f;
+    a = a<<7;
+    a |= b;
+    *v = a;
+    return 2;
+  }
+
+  p++;
+  a = a<<14;
+  a |= *p;
+  /* a: p0<<14 | p2 (unmasked) */
+  if (!(a&0x80))
+  {
+    a &= (0x7f<<14)|(0x7f);
+    b &= 0x7f;
+    b = b<<7;
+    a |= b;
+    *v = a;
+    return 3;
+  }
+
+  /* CSE1 from below */
+  a &= (0x7f<<14)|(0x7f);
+  p++;
+  b = b<<14;
+  b |= *p;
+  /* b: p1<<14 | p3 (unmasked) */
+  if (!(b&0x80))
+  {
+    b &= (0x7f<<14)|(0x7f);
+    /* moved CSE1 up */
+    /* a &= (0x7f<<14)|(0x7f); */
+    a = a<<7;
+    a |= b;
+    *v = a;
+    return 4;
+  }
+
+  /* a: p0<<14 | p2 (masked) */
+  /* b: p1<<14 | p3 (unmasked) */
+  /* 1:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
+  /* moved CSE1 up */
+  /* a &= (0x7f<<14)|(0x7f); */
+  b &= (0x7f<<14)|(0x7f);
+  s = a;
+  /* s: p0<<14 | p2 (masked) */
+
+  p++;
+  a = a<<14;
+  a |= *p;
+  /* a: p0<<28 | p2<<14 | p4 (unmasked) */
+  if (!(a&0x80))
+  {
+    /* we can skip these cause they were (effectively) done above in calc'ing s */
+    /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
+    /* b &= (0x7f<<14)|(0x7f); */
+    b = b<<7;
+    a |= b;
+    s = s>>18;
+    *v = ((u64)s)<<32 | a;
+    return 5;
+  }
+
+  /* 2:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
+  s = s<<7;
+  s |= b;
+  /* s: p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
+
+  p++;
+  b = b<<14;
+  b |= *p;
+  /* b: p1<<28 | p3<<14 | p5 (unmasked) */
+  if (!(b&0x80))
+  {
+    /* we can skip this cause it was (effectively) done above in calc'ing s */
+    /* b &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
+    a &= (0x7f<<14)|(0x7f);
+    a = a<<7;
+    a |= b;
+    s = s>>18;
+    *v = ((u64)s)<<32 | a;
+    return 6;
+  }
+
+  p++;
+  a = a<<14;
+  a |= *p;
+  /* a: p2<<28 | p4<<14 | p6 (unmasked) */
+  if (!(a&0x80))
+  {
+    a &= (0x7f<<28)|(0x7f<<14)|(0x7f);
+    b &= (0x7f<<14)|(0x7f);
+    b = b<<7;
+    a |= b;
+    s = s>>11;
+    *v = ((u64)s)<<32 | a;
+    return 7;
+  }
+
+  /* CSE2 from below */
+  a &= (0x7f<<14)|(0x7f);
+  p++;
+  b = b<<14;
+  b |= *p;
+  /* b: p3<<28 | p5<<14 | p7 (unmasked) */
+  if (!(b&0x80))
+  {
+    b &= (0x7f<<28)|(0x7f<<14)|(0x7f);
+    /* moved CSE2 up */
+    /* a &= (0x7f<<14)|(0x7f); */
+    a = a<<7;
+    a |= b;
+    s = s>>4;
+    *v = ((u64)s)<<32 | a;
+    return 8;
+  }
+
+  p++;
+  a = a<<15;
+  a |= *p;
+  /* a: p4<<29 | p6<<15 | p8 (unmasked) */
+
+  /* moved CSE2 up */
+  /* a &= (0x7f<<29)|(0x7f<<15)|(0xff); */
+  b &= (0x7f<<14)|(0x7f);
+  b = b<<8;
+  a |= b;
+
+  s = s<<4;
+  b = p[-4];
+  b &= 0x7f;
+  b = b>>3;
+  s |= b;
+
+  *v = ((u64)s)<<32 | a;
+
+  return 9;
+}
+
+/*
+** Read a 32-bit variable-length integer from memory starting at p[0].
+** Return the number of bytes read.  The value is stored in *v.
+** A MACRO version, getVarint32, is provided which inlines the 
+** single-byte case.  All code should use the MACRO version as 
+** this function assumes the single-byte case has already been handled.
+*/
+int sqlite3GetVarint32(const unsigned char *p, u32 *v){
+  u32 a,b;
+
+  a = *p;
+  /* a: p0 (unmasked) */
+#ifndef getVarint32
+  if (!(a&0x80))
+  {
+    *v = a;
+    return 1;
+  }
+#endif
+
+  p++;
+  b = *p;
+  /* b: p1 (unmasked) */
+  if (!(b&0x80))
+  {
+    a &= 0x7f;
+    a = a<<7;
+    *v = a | b;
+    return 2;
+  }
+
+  p++;
+  a = a<<14;
+  a |= *p;
+  /* a: p0<<14 | p2 (unmasked) */
+  if (!(a&0x80))
+  {
+    a &= (0x7f<<14)|(0x7f);
+    b &= 0x7f;
+    b = b<<7;
+    *v = a | b;
+    return 3;
+  }
+
+  p++;
+  b = b<<14;
+  b |= *p;
+  /* b: p1<<14 | p3 (unmasked) */
+  if (!(b&0x80))
+  {
+    b &= (0x7f<<14)|(0x7f);
+    a &= (0x7f<<14)|(0x7f);
+    a = a<<7;
+    *v = a | b;
+    return 4;
+  }
+
+  p++;
+  a = a<<14;
+  a |= *p;
+  /* a: p0<<28 | p2<<14 | p4 (unmasked) */
+  if (!(a&0x80))
+  {
+    a &= (0x7f<<28)|(0x7f<<14)|(0x7f);
+    b &= (0x7f<<28)|(0x7f<<14)|(0x7f);
+    b = b<<7;
+    *v = a | b;
+    return 5;
+  }
+
+  /* We can only reach this point when reading a corrupt database
+  ** file.  In that case we are not in any hurry.  Use the (relatively
+  ** slow) general-purpose sqlite3GetVarint() routine to extract the
+  ** value. */
+  {
+    u64 v64;
+    int n;
+
+    p -= 4;
+    n = sqlite3GetVarint(p, &v64);
+    assert( n>5 && n<=9 );
+    *v = (u32)v64;
+    return n;
+  }
+}
+
+/*
+** Return the number of bytes that will be needed to store the given
+** 64-bit integer.
+*/
+int sqlite3VarintLen(u64 v){
+  int i = 0;
+  do{
+    i++;
+    v >>= 7;
+  }while( v!=0 && i<9 );
+  return i;
+}
+
+
+/*
+** Read or write a four-byte big-endian integer value.
+*/
+u32 sqlite3Get4byte(const u8 *p){
+  return (p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
+}
+void sqlite3Put4byte(unsigned char *p, u32 v){
+  p[0] = v>>24;
+  p[1] = v>>16;
+  p[2] = v>>8;
+  p[3] = v;
+}
+
+
+
+#if !defined(SQLITE_OMIT_BLOB_LITERAL) || defined(SQLITE_HAS_CODEC)
+/*
+** Translate a single byte of Hex into an integer.
+** This routinen only works if h really is a valid hexadecimal
+** character:  0..9a..fA..F
+*/
+static int hexToInt(int h){
+  assert( (h>='0' && h<='9') ||  (h>='a' && h<='f') ||  (h>='A' && h<='F') );
+#ifdef SQLITE_ASCII
+  h += 9*(1&(h>>6));
+#endif
+#ifdef SQLITE_EBCDIC
+  h += 9*(1&~(h>>4));
+#endif
+  return h & 0xf;
+}
+#endif /* !SQLITE_OMIT_BLOB_LITERAL || SQLITE_HAS_CODEC */
+
+#if !defined(SQLITE_OMIT_BLOB_LITERAL) || defined(SQLITE_HAS_CODEC)
+/*
+** Convert a BLOB literal of the form "x'hhhhhh'" into its binary
+** value.  Return a pointer to its binary value.  Space to hold the
+** binary value has been obtained from malloc and must be freed by
+** the calling routine.
+*/
+void *sqlite3HexToBlob(sqlite3 *db, const char *z, int n){
+  char *zBlob;
+  int i;
+
+  zBlob = (char *)sqlite3DbMallocRaw(db, n/2 + 1);
+  n--;
+  if( zBlob ){
+    for(i=0; i<n; i+=2){
+      zBlob[i/2] = (hexToInt(z[i])<<4) | hexToInt(z[i+1]);
+    }
+    zBlob[i/2] = 0;
+  }
+  return zBlob;
+}
+#endif /* !SQLITE_OMIT_BLOB_LITERAL || SQLITE_HAS_CODEC */
+
+
+/*
+** Change the sqlite.magic from SQLITE_MAGIC_OPEN to SQLITE_MAGIC_BUSY.
+** Return an error (non-zero) if the magic was not SQLITE_MAGIC_OPEN
+** when this routine is called.
+**
+** This routine is called when entering an SQLite API.  The SQLITE_MAGIC_OPEN
+** value indicates that the database connection passed into the API is
+** open and is not being used by another thread.  By changing the value
+** to SQLITE_MAGIC_BUSY we indicate that the connection is in use.
+** sqlite3SafetyOff() below will change the value back to SQLITE_MAGIC_OPEN
+** when the API exits. 
+**
+** This routine is a attempt to detect if two threads use the
+** same sqlite* pointer at the same time.  There is a race 
+** condition so it is possible that the error is not detected.
+** But usually the problem will be seen.  The result will be an
+** error which can be used to debug the application that is
+** using SQLite incorrectly.
+**
+** Ticket #202:  If db->magic is not a valid open value, take care not
+** to modify the db structure at all.  It could be that db is a stale
+** pointer.  In other words, it could be that there has been a prior
+** call to sqlite3_close(db) and db has been deallocated.  And we do
+** not want to write into deallocated memory.
+*/
+#ifdef SQLITE_DEBUG
+int sqlite3SafetyOn(sqlite3 *db){
+  if( db->magic==SQLITE_MAGIC_OPEN ){
+    db->magic = SQLITE_MAGIC_BUSY;
+    assert( sqlite3_mutex_held(db->mutex) );
+    return 0;
+  }else if( db->magic==SQLITE_MAGIC_BUSY ){
+    db->magic = SQLITE_MAGIC_ERROR;
+    db->u1.isInterrupted = 1;
+  }
+  return 1;
+}
+#endif
+
+/*
+** Change the magic from SQLITE_MAGIC_BUSY to SQLITE_MAGIC_OPEN.
+** Return an error (non-zero) if the magic was not SQLITE_MAGIC_BUSY
+** when this routine is called.
+*/
+#ifdef SQLITE_DEBUG
+int sqlite3SafetyOff(sqlite3 *db){
+  if( db->magic==SQLITE_MAGIC_BUSY ){
+    db->magic = SQLITE_MAGIC_OPEN;
+    assert( sqlite3_mutex_held(db->mutex) );
+    return 0;
+  }else{
+    db->magic = SQLITE_MAGIC_ERROR;
+    db->u1.isInterrupted = 1;
+    return 1;
+  }
+}
+#endif
+
+/*
+** Check to make sure we have a valid db pointer.  This test is not
+** foolproof but it does provide some measure of protection against
+** misuse of the interface such as passing in db pointers that are
+** NULL or which have been previously closed.  If this routine returns
+** 1 it means that the db pointer is valid and 0 if it should not be
+** dereferenced for any reason.  The calling function should invoke
+** SQLITE_MISUSE immediately.
+**
+** sqlite3SafetyCheckOk() requires that the db pointer be valid for
+** use.  sqlite3SafetyCheckSickOrOk() allows a db pointer that failed to
+** open properly and is not fit for general use but which can be
+** used as an argument to sqlite3_errmsg() or sqlite3_close().
+*/
+int sqlite3SafetyCheckOk(sqlite3 *db){
+  int magic;
+  if( db==0 ) return 0;
+  magic = db->magic;
+  if( magic!=SQLITE_MAGIC_OPEN &&
+      magic!=SQLITE_MAGIC_BUSY ) return 0;
+  return 1;
+}
+int sqlite3SafetyCheckSickOrOk(sqlite3 *db){
+  int magic;
+  if( db==0 ) return 0;
+  magic = db->magic;
+  if( magic!=SQLITE_MAGIC_SICK &&
+      magic!=SQLITE_MAGIC_OPEN &&
+      magic!=SQLITE_MAGIC_BUSY ) return 0;
+  return 1;
+}
diff --git a/third_party/sqlite/src/vacuum.c b/third_party/sqlite/src/vacuum.c
new file mode 100755
index 0000000..45bc61e
--- /dev/null
+++ b/third_party/sqlite/src/vacuum.c
@@ -0,0 +1,293 @@
+/*
+** 2003 April 6
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code used to implement the VACUUM command.
+**
+** Most of the code in this file may be omitted by defining the
+** SQLITE_OMIT_VACUUM macro.
+**
+** $Id: vacuum.c,v 1.81 2008/07/08 19:34:07 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "vdbeInt.h"
+
+#if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
+/*
+** Execute zSql on database db. Return an error code.
+*/
+static int execSql(sqlite3 *db, const char *zSql){
+  sqlite3_stmt *pStmt;
+  if( !zSql ){
+    return SQLITE_NOMEM;
+  }
+  if( SQLITE_OK!=sqlite3_prepare(db, zSql, -1, &pStmt, 0) ){
+    return sqlite3_errcode(db);
+  }
+  while( SQLITE_ROW==sqlite3_step(pStmt) ){}
+  return sqlite3_finalize(pStmt);
+}
+
+/*
+** Execute zSql on database db. The statement returns exactly
+** one column. Execute this as SQL on the same database.
+*/
+static int execExecSql(sqlite3 *db, const char *zSql){
+  sqlite3_stmt *pStmt;
+  int rc;
+
+  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
+  if( rc!=SQLITE_OK ) return rc;
+
+  while( SQLITE_ROW==sqlite3_step(pStmt) ){
+    rc = execSql(db, (char*)sqlite3_column_text(pStmt, 0));
+    if( rc!=SQLITE_OK ){
+      sqlite3_finalize(pStmt);
+      return rc;
+    }
+  }
+
+  return sqlite3_finalize(pStmt);
+}
+
+/*
+** The non-standard VACUUM command is used to clean up the database,
+** collapse free space, etc.  It is modelled after the VACUUM command
+** in PostgreSQL.
+**
+** In version 1.0.x of SQLite, the VACUUM command would call
+** gdbm_reorganize() on all the database tables.  But beginning
+** with 2.0.0, SQLite no longer uses GDBM so this command has
+** become a no-op.
+*/
+void sqlite3Vacuum(Parse *pParse){
+  Vdbe *v = sqlite3GetVdbe(pParse);
+  if( v ){
+    sqlite3VdbeAddOp2(v, OP_Vacuum, 0, 0);
+  }
+  return;
+}
+
+/*
+** This routine implements the OP_Vacuum opcode of the VDBE.
+*/
+int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
+  int rc = SQLITE_OK;     /* Return code from service routines */
+  Btree *pMain;           /* The database being vacuumed */
+  Btree *pTemp;           /* The temporary database we vacuum into */
+  char *zSql = 0;         /* SQL statements */
+  int saved_flags;        /* Saved value of the db->flags */
+  int saved_nChange;      /* Saved value of db->nChange */
+  int saved_nTotalChange; /* Saved value of db->nTotalChange */
+  Db *pDb = 0;            /* Database to detach at end of vacuum */
+  int nRes;
+
+  /* Save the current value of the write-schema flag before setting it. */
+  saved_flags = db->flags;
+  saved_nChange = db->nChange;
+  saved_nTotalChange = db->nTotalChange;
+  db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;
+
+  if( !db->autoCommit ){
+    sqlite3SetString(pzErrMsg, db, "cannot VACUUM from within a transaction");
+    rc = SQLITE_ERROR;
+    goto end_of_vacuum;
+  }
+  pMain = db->aDb[0].pBt;
+
+  /* Attach the temporary database as 'vacuum_db'. The synchronous pragma
+  ** can be set to 'off' for this file, as it is not recovered if a crash
+  ** occurs anyway. The integrity of the database is maintained by a
+  ** (possibly synchronous) transaction opened on the main database before
+  ** sqlite3BtreeCopyFile() is called.
+  **
+  ** An optimisation would be to use a non-journaled pager.
+  ** (Later:) I tried setting "PRAGMA vacuum_db.journal_mode=OFF" but
+  ** that actually made the VACUUM run slower.  Very little journalling
+  ** actually occurs when doing a vacuum since the vacuum_db is initially
+  ** empty.  Only the journal header is written.  Apparently it takes more
+  ** time to parse and run the PRAGMA to turn journalling off than it does
+  ** to write the journal header file.
+  */
+  zSql = "ATTACH '' AS vacuum_db;";
+  rc = execSql(db, zSql);
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  pDb = &db->aDb[db->nDb-1];
+  assert( strcmp(db->aDb[db->nDb-1].zName,"vacuum_db")==0 );
+  pTemp = db->aDb[db->nDb-1].pBt;
+
+  nRes = sqlite3BtreeGetReserve(pMain);
+
+  /* A VACUUM cannot change the pagesize of an encrypted database. */
+#ifdef SQLITE_HAS_CODEC
+  if( db->nextPagesize ){
+    extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
+    int nKey;
+    char *zKey;
+    sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
+    if( nKey ) db->nextPagesize = 0;
+  }
+#endif
+
+  if( sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain), nRes)
+   || sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes)
+   || db->mallocFailed 
+  ){
+    rc = SQLITE_NOMEM;
+    goto end_of_vacuum;
+  }
+  rc = execSql(db, "PRAGMA vacuum_db.synchronous=OFF");
+  if( rc!=SQLITE_OK ){
+    goto end_of_vacuum;
+  }
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+  sqlite3BtreeSetAutoVacuum(pTemp, db->nextAutovac>=0 ? db->nextAutovac :
+                                           sqlite3BtreeGetAutoVacuum(pMain));
+#endif
+
+  /* Begin a transaction */
+  rc = execSql(db, "BEGIN EXCLUSIVE;");
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+
+  /* Query the schema of the main database. Create a mirror schema
+  ** in the temporary database.
+  */
+  rc = execExecSql(db, 
+      "SELECT 'CREATE TABLE vacuum_db.' || substr(sql,14) "
+      "  FROM sqlite_master WHERE type='table' AND name!='sqlite_sequence'"
+      "   AND rootpage>0"
+  );
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  rc = execExecSql(db, 
+      "SELECT 'CREATE INDEX vacuum_db.' || substr(sql,14)"
+      "  FROM sqlite_master WHERE sql LIKE 'CREATE INDEX %' ");
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  rc = execExecSql(db, 
+      "SELECT 'CREATE UNIQUE INDEX vacuum_db.' || substr(sql,21) "
+      "  FROM sqlite_master WHERE sql LIKE 'CREATE UNIQUE INDEX %'");
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+
+  /* Loop through the tables in the main database. For each, do
+  ** an "INSERT INTO vacuum_db.xxx SELECT * FROM xxx;" to copy
+  ** the contents to the temporary database.
+  */
+  rc = execExecSql(db, 
+      "SELECT 'INSERT INTO vacuum_db.' || quote(name) "
+      "|| ' SELECT * FROM ' || quote(name) || ';'"
+      "FROM sqlite_master "
+      "WHERE type = 'table' AND name!='sqlite_sequence' "
+      "  AND rootpage>0"
+
+  );
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+
+  /* Copy over the sequence table
+  */
+  rc = execExecSql(db, 
+      "SELECT 'DELETE FROM vacuum_db.' || quote(name) || ';' "
+      "FROM vacuum_db.sqlite_master WHERE name='sqlite_sequence' "
+  );
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  rc = execExecSql(db, 
+      "SELECT 'INSERT INTO vacuum_db.' || quote(name) "
+      "|| ' SELECT * FROM ' || quote(name) || ';' "
+      "FROM vacuum_db.sqlite_master WHERE name=='sqlite_sequence';"
+  );
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+
+
+  /* Copy the triggers, views, and virtual tables from the main database
+  ** over to the temporary database.  None of these objects has any
+  ** associated storage, so all we have to do is copy their entries
+  ** from the SQLITE_MASTER table.
+  */
+  rc = execSql(db,
+      "INSERT INTO vacuum_db.sqlite_master "
+      "  SELECT type, name, tbl_name, rootpage, sql"
+      "    FROM sqlite_master"
+      "   WHERE type='view' OR type='trigger'"
+      "      OR (type='table' AND rootpage=0)"
+  );
+  if( rc ) goto end_of_vacuum;
+
+  /* At this point, unless the main db was completely empty, there is now a
+  ** transaction open on the vacuum database, but not on the main database.
+  ** Open a btree level transaction on the main database. This allows a
+  ** call to sqlite3BtreeCopyFile(). The main database btree level
+  ** transaction is then committed, so the SQL level never knows it was
+  ** opened for writing. This way, the SQL transaction used to create the
+  ** temporary database never needs to be committed.
+  */
+  if( rc==SQLITE_OK ){
+    u32 meta;
+    int i;
+
+    /* This array determines which meta meta values are preserved in the
+    ** vacuum.  Even entries are the meta value number and odd entries
+    ** are an increment to apply to the meta value after the vacuum.
+    ** The increment is used to increase the schema cookie so that other
+    ** connections to the same database will know to reread the schema.
+    */
+    static const unsigned char aCopy[] = {
+       1, 1,    /* Add one to the old schema cookie */
+       3, 0,    /* Preserve the default page cache size */
+       5, 0,    /* Preserve the default text encoding */
+       6, 0,    /* Preserve the user version */
+    };
+
+    assert( 1==sqlite3BtreeIsInTrans(pTemp) );
+    assert( 1==sqlite3BtreeIsInTrans(pMain) );
+
+    /* Copy Btree meta values */
+    for(i=0; i<sizeof(aCopy)/sizeof(aCopy[0]); i+=2){
+      rc = sqlite3BtreeGetMeta(pMain, aCopy[i], &meta);
+      if( rc!=SQLITE_OK ) goto end_of_vacuum;
+      rc = sqlite3BtreeUpdateMeta(pTemp, aCopy[i], meta+aCopy[i+1]);
+      if( rc!=SQLITE_OK ) goto end_of_vacuum;
+    }
+
+    rc = sqlite3BtreeCopyFile(pMain, pTemp);
+    if( rc!=SQLITE_OK ) goto end_of_vacuum;
+    rc = sqlite3BtreeCommit(pTemp);
+    if( rc!=SQLITE_OK ) goto end_of_vacuum;
+    rc = sqlite3BtreeCommit(pMain);
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = sqlite3BtreeSetPageSize(pMain, sqlite3BtreeGetPageSize(pTemp), nRes);
+  }
+
+end_of_vacuum:
+  /* Restore the original value of db->flags */
+  db->flags = saved_flags;
+  db->nChange = saved_nChange;
+  db->nTotalChange = saved_nTotalChange;
+
+  /* Currently there is an SQL level transaction open on the vacuum
+  ** database. No locks are held on any other files (since the main file
+  ** was committed at the btree level). So it safe to end the transaction
+  ** by manually setting the autoCommit flag to true and detaching the
+  ** vacuum database. The vacuum_db journal file is deleted when the pager
+  ** is closed by the DETACH.
+  */
+  db->autoCommit = 1;
+
+  if( pDb ){
+    sqlite3BtreeClose(pDb->pBt);
+    pDb->pBt = 0;
+    pDb->pSchema = 0;
+  }
+
+  sqlite3ResetInternalSchema(db, 0);
+
+  return rc;
+}
+#endif  /* SQLITE_OMIT_VACUUM && SQLITE_OMIT_ATTACH */
diff --git a/third_party/sqlite/src/vdbe.c b/third_party/sqlite/src/vdbe.c
new file mode 100755
index 0000000..b326c79
--- /dev/null
+++ b/third_party/sqlite/src/vdbe.c
@@ -0,0 +1,5118 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** The code in this file implements execution method of the 
+** Virtual Database Engine (VDBE).  A separate file ("vdbeaux.c")
+** handles housekeeping details such as creating and deleting
+** VDBE instances.  This file is solely interested in executing
+** the VDBE program.
+**
+** In the external interface, an "sqlite3_stmt*" is an opaque pointer
+** to a VDBE.
+**
+** The SQL parser generates a program which is then executed by
+** the VDBE to do the work of the SQL statement.  VDBE programs are 
+** similar in form to assembly language.  The program consists of
+** a linear sequence of operations.  Each operation has an opcode 
+** and 5 operands.  Operands P1, P2, and P3 are integers.  Operand P4 
+** is a null-terminated string.  Operand P5 is an unsigned character.
+** Few opcodes use all 5 operands.
+**
+** Computation results are stored on a set of registers numbered beginning
+** with 1 and going up to Vdbe.nMem.  Each register can store
+** either an integer, a null-terminated string, a floating point
+** number, or the SQL "NULL" value.  An implicit conversion from one
+** type to the other occurs as necessary.
+** 
+** Most of the code in this file is taken up by the sqlite3VdbeExec()
+** function which does the work of interpreting a VDBE program.
+** But other routines are also provided to help in building up
+** a program instruction by instruction.
+**
+** Various scripts scan this source file in order to generate HTML
+** documentation, headers files, or other derived files.  The formatting
+** of the code in this file is, therefore, important.  See other comments
+** in this file for details.  If in doubt, do not deviate from existing
+** commenting and indentation practices when changing or adding code.
+**
+** $Id: vdbe.c,v 1.772 2008/08/02 15:10:09 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+#include "vdbeInt.h"
+
+/*
+** The following global variable is incremented every time a cursor
+** moves, either by the OP_MoveXX, OP_Next, or OP_Prev opcodes.  The test
+** procedures use this information to make sure that indices are
+** working correctly.  This variable has no function other than to
+** help verify the correct operation of the library.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_search_count = 0;
+#endif
+
+/*
+** When this global variable is positive, it gets decremented once before
+** each instruction in the VDBE.  When reaches zero, the u1.isInterrupted
+** field of the sqlite3 structure is set in order to simulate and interrupt.
+**
+** This facility is used for testing purposes only.  It does not function
+** in an ordinary build.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_interrupt_count = 0;
+#endif
+
+/*
+** The next global variable is incremented each type the OP_Sort opcode
+** is executed.  The test procedures use this information to make sure that
+** sorting is occurring or not occurring at appropriate times.   This variable
+** has no function other than to help verify the correct operation of the
+** library.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_sort_count = 0;
+#endif
+
+/*
+** The next global variable records the size of the largest MEM_Blob
+** or MEM_Str that has been used by a VDBE opcode.  The test procedures
+** use this information to make sure that the zero-blob functionality
+** is working correctly.   This variable has no function other than to
+** help verify the correct operation of the library.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_max_blobsize = 0;
+static void updateMaxBlobsize(Mem *p){
+  if( (p->flags & (MEM_Str|MEM_Blob))!=0 && p->n>sqlite3_max_blobsize ){
+    sqlite3_max_blobsize = p->n;
+  }
+}
+#endif
+
+/*
+** Test a register to see if it exceeds the current maximum blob size.
+** If it does, record the new maximum blob size.
+*/
+#if defined(SQLITE_TEST) && !defined(SQLITE_OMIT_BUILTIN_TEST)
+# define UPDATE_MAX_BLOBSIZE(P)  updateMaxBlobsize(P)
+#else
+# define UPDATE_MAX_BLOBSIZE(P)
+#endif
+
+/*
+** Release the memory associated with a register.  This
+** leaves the Mem.flags field in an inconsistent state.
+*/
+#define Release(P) if((P)->flags&MEM_Dyn){ sqlite3VdbeMemRelease(P); }
+
+/*
+** Convert the given register into a string if it isn't one
+** already. Return non-zero if a malloc() fails.
+*/
+#define Stringify(P, enc) \
+   if(((P)->flags&(MEM_Str|MEM_Blob))==0 && sqlite3VdbeMemStringify(P,enc)) \
+     { goto no_mem; }
+
+/*
+** An ephemeral string value (signified by the MEM_Ephem flag) contains
+** a pointer to a dynamically allocated string where some other entity
+** is responsible for deallocating that string.  Because the register
+** does not control the string, it might be deleted without the register
+** knowing it.
+**
+** This routine converts an ephemeral string into a dynamically allocated
+** string that the register itself controls.  In other words, it
+** converts an MEM_Ephem string into an MEM_Dyn string.
+*/
+#define Deephemeralize(P) \
+   if( ((P)->flags&MEM_Ephem)!=0 \
+       && sqlite3VdbeMemMakeWriteable(P) ){ goto no_mem;}
+
+/*
+** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
+** P if required.
+*/
+#define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
+
+/*
+** Argument pMem points at a register that will be passed to a
+** user-defined function or returned to the user as the result of a query.
+** The second argument, 'db_enc' is the text encoding used by the vdbe for
+** register variables.  This routine sets the pMem->enc and pMem->type
+** variables used by the sqlite3_value_*() routines.
+*/
+#define storeTypeInfo(A,B) _storeTypeInfo(A)
+static void _storeTypeInfo(Mem *pMem){
+  int flags = pMem->flags;
+  if( flags & MEM_Null ){
+    pMem->type = SQLITE_NULL;
+  }
+  else if( flags & MEM_Int ){
+    pMem->type = SQLITE_INTEGER;
+  }
+  else if( flags & MEM_Real ){
+    pMem->type = SQLITE_FLOAT;
+  }
+  else if( flags & MEM_Str ){
+    pMem->type = SQLITE_TEXT;
+  }else{
+    pMem->type = SQLITE_BLOB;
+  }
+}
+
+/*
+** Properties of opcodes.  The OPFLG_INITIALIZER macro is
+** created by mkopcodeh.awk during compilation.  Data is obtained
+** from the comments following the "case OP_xxxx:" statements in
+** this file.  
+*/
+static unsigned char opcodeProperty[] = OPFLG_INITIALIZER;
+
+/*
+** Return true if an opcode has any of the OPFLG_xxx properties
+** specified by mask.
+*/
+int sqlite3VdbeOpcodeHasProperty(int opcode, int mask){
+  assert( opcode>0 && opcode<sizeof(opcodeProperty) );
+  return (opcodeProperty[opcode]&mask)!=0;
+}
+
+/*
+** Allocate cursor number iCur.  Return a pointer to it.  Return NULL
+** if we run out of memory.
+*/
+static Cursor *allocateCursor(
+  Vdbe *p, 
+  int iCur, 
+  Op *pOp,
+  int iDb, 
+  int isBtreeCursor
+){
+  /* Find the memory cell that will be used to store the blob of memory
+  ** required for this Cursor structure. It is convenient to use a 
+  ** vdbe memory cell to manage the memory allocation required for a
+  ** Cursor structure for the following reasons:
+  **
+  **   * Sometimes cursor numbers are used for a couple of different
+  **     purposes in a vdbe program. The different uses might require
+  **     different sized allocations. Memory cells provide growable
+  **     allocations.
+  **
+  **   * When using ENABLE_MEMORY_MANAGEMENT, memory cell buffers can
+  **     be freed lazily via the sqlite3_release_memory() API. This
+  **     minimizes the number of malloc calls made by the system.
+  **
+  ** Memory cells for cursors are allocated at the top of the address
+  ** space. Memory cell (p->nMem) corresponds to cursor 0. Space for
+  ** cursor 1 is managed by memory cell (p->nMem-1), etc.
+  */
+  Mem *pMem = &p->aMem[p->nMem-iCur];
+
+  int nByte;
+  Cursor *pCx = 0;
+  /* If the opcode of pOp is OP_SetNumColumns, then pOp->p2 contains
+  ** the number of fields in the records contained in the table or
+  ** index being opened. Use this to reserve space for the 
+  ** Cursor.aType[] array.
+  */
+  int nField = 0;
+  if( pOp->opcode==OP_SetNumColumns || pOp->opcode==OP_OpenEphemeral ){
+    nField = pOp->p2;
+  }
+  nByte = 
+      sizeof(Cursor) + 
+      (isBtreeCursor?sqlite3BtreeCursorSize():0) + 
+      2*nField*sizeof(u32);
+
+  assert( iCur<p->nCursor );
+  if( p->apCsr[iCur] ){
+    sqlite3VdbeFreeCursor(p, p->apCsr[iCur]);
+    p->apCsr[iCur] = 0;
+  }
+  if( SQLITE_OK==sqlite3VdbeMemGrow(pMem, nByte, 0) ){
+    p->apCsr[iCur] = pCx = (Cursor *)pMem->z;
+    memset(pMem->z, 0, nByte);
+    pCx->iDb = iDb;
+    pCx->nField = nField;
+    if( nField ){
+      pCx->aType = (u32 *)&pMem->z[sizeof(Cursor)];
+    }
+    if( isBtreeCursor ){
+      pCx->pCursor = (BtCursor *)&pMem->z[sizeof(Cursor)+2*nField*sizeof(u32)];
+    }
+  }
+  return pCx;
+}
+
+/*
+** Try to convert a value into a numeric representation if we can
+** do so without loss of information.  In other words, if the string
+** looks like a number, convert it into a number.  If it does not
+** look like a number, leave it alone.
+*/
+static void applyNumericAffinity(Mem *pRec){
+  if( (pRec->flags & (MEM_Real|MEM_Int))==0 ){
+    int realnum;
+    sqlite3VdbeMemNulTerminate(pRec);
+    if( (pRec->flags&MEM_Str)
+         && sqlite3IsNumber(pRec->z, &realnum, pRec->enc) ){
+      i64 value;
+      sqlite3VdbeChangeEncoding(pRec, SQLITE_UTF8);
+      if( !realnum && sqlite3Atoi64(pRec->z, &value) ){
+        pRec->u.i = value;
+        MemSetTypeFlag(pRec, MEM_Int);
+      }else{
+        sqlite3VdbeMemRealify(pRec);
+      }
+    }
+  }
+}
+
+/*
+** Processing is determine by the affinity parameter:
+**
+** SQLITE_AFF_INTEGER:
+** SQLITE_AFF_REAL:
+** SQLITE_AFF_NUMERIC:
+**    Try to convert pRec to an integer representation or a 
+**    floating-point representation if an integer representation
+**    is not possible.  Note that the integer representation is
+**    always preferred, even if the affinity is REAL, because
+**    an integer representation is more space efficient on disk.
+**
+** SQLITE_AFF_TEXT:
+**    Convert pRec to a text representation.
+**
+** SQLITE_AFF_NONE:
+**    No-op.  pRec is unchanged.
+*/
+static void applyAffinity(
+  Mem *pRec,          /* The value to apply affinity to */
+  char affinity,      /* The affinity to be applied */
+  u8 enc              /* Use this text encoding */
+){
+  if( affinity==SQLITE_AFF_TEXT ){
+    /* Only attempt the conversion to TEXT if there is an integer or real
+    ** representation (blob and NULL do not get converted) but no string
+    ** representation.
+    */
+    if( 0==(pRec->flags&MEM_Str) && (pRec->flags&(MEM_Real|MEM_Int)) ){
+      sqlite3VdbeMemStringify(pRec, enc);
+    }
+    pRec->flags &= ~(MEM_Real|MEM_Int);
+  }else if( affinity!=SQLITE_AFF_NONE ){
+    assert( affinity==SQLITE_AFF_INTEGER || affinity==SQLITE_AFF_REAL
+             || affinity==SQLITE_AFF_NUMERIC );
+    applyNumericAffinity(pRec);
+    if( pRec->flags & MEM_Real ){
+      sqlite3VdbeIntegerAffinity(pRec);
+    }
+  }
+}
+
+/*
+** Try to convert the type of a function argument or a result column
+** into a numeric representation.  Use either INTEGER or REAL whichever
+** is appropriate.  But only do the conversion if it is possible without
+** loss of information and return the revised type of the argument.
+**
+** This is an EXPERIMENTAL api and is subject to change or removal.
+*/
+int sqlite3_value_numeric_type(sqlite3_value *pVal){
+  Mem *pMem = (Mem*)pVal;
+  applyNumericAffinity(pMem);
+  storeTypeInfo(pMem, 0);
+  return pMem->type;
+}
+
+/*
+** Exported version of applyAffinity(). This one works on sqlite3_value*, 
+** not the internal Mem* type.
+*/
+void sqlite3ValueApplyAffinity(
+  sqlite3_value *pVal, 
+  u8 affinity, 
+  u8 enc
+){
+  applyAffinity((Mem *)pVal, affinity, enc);
+}
+
+#ifdef SQLITE_DEBUG
+/*
+** Write a nice string representation of the contents of cell pMem
+** into buffer zBuf, length nBuf.
+*/
+void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf){
+  char *zCsr = zBuf;
+  int f = pMem->flags;
+
+  static const char *const encnames[] = {"(X)", "(8)", "(16LE)", "(16BE)"};
+
+  if( f&MEM_Blob ){
+    int i;
+    char c;
+    if( f & MEM_Dyn ){
+      c = 'z';
+      assert( (f & (MEM_Static|MEM_Ephem))==0 );
+    }else if( f & MEM_Static ){
+      c = 't';
+      assert( (f & (MEM_Dyn|MEM_Ephem))==0 );
+    }else if( f & MEM_Ephem ){
+      c = 'e';
+      assert( (f & (MEM_Static|MEM_Dyn))==0 );
+    }else{
+      c = 's';
+    }
+
+    sqlite3_snprintf(100, zCsr, "%c", c);
+    zCsr += strlen(zCsr);
+    sqlite3_snprintf(100, zCsr, "%d[", pMem->n);
+    zCsr += strlen(zCsr);
+    for(i=0; i<16 && i<pMem->n; i++){
+      sqlite3_snprintf(100, zCsr, "%02X", ((int)pMem->z[i] & 0xFF));
+      zCsr += strlen(zCsr);
+    }
+    for(i=0; i<16 && i<pMem->n; i++){
+      char z = pMem->z[i];
+      if( z<32 || z>126 ) *zCsr++ = '.';
+      else *zCsr++ = z;
+    }
+
+    sqlite3_snprintf(100, zCsr, "]%s", encnames[pMem->enc]);
+    zCsr += strlen(zCsr);
+    if( f & MEM_Zero ){
+      sqlite3_snprintf(100, zCsr,"+%lldz",pMem->u.i);
+      zCsr += strlen(zCsr);
+    }
+    *zCsr = '\0';
+  }else if( f & MEM_Str ){
+    int j, k;
+    zBuf[0] = ' ';
+    if( f & MEM_Dyn ){
+      zBuf[1] = 'z';
+      assert( (f & (MEM_Static|MEM_Ephem))==0 );
+    }else if( f & MEM_Static ){
+      zBuf[1] = 't';
+      assert( (f & (MEM_Dyn|MEM_Ephem))==0 );
+    }else if( f & MEM_Ephem ){
+      zBuf[1] = 'e';
+      assert( (f & (MEM_Static|MEM_Dyn))==0 );
+    }else{
+      zBuf[1] = 's';
+    }
+    k = 2;
+    sqlite3_snprintf(100, &zBuf[k], "%d", pMem->n);
+    k += strlen(&zBuf[k]);
+    zBuf[k++] = '[';
+    for(j=0; j<15 && j<pMem->n; j++){
+      u8 c = pMem->z[j];
+      if( c>=0x20 && c<0x7f ){
+        zBuf[k++] = c;
+      }else{
+        zBuf[k++] = '.';
+      }
+    }
+    zBuf[k++] = ']';
+    sqlite3_snprintf(100,&zBuf[k], encnames[pMem->enc]);
+    k += strlen(&zBuf[k]);
+    zBuf[k++] = 0;
+  }
+}
+#endif
+
+#ifdef SQLITE_DEBUG
+/*
+** Print the value of a register for tracing purposes:
+*/
+static void memTracePrint(FILE *out, Mem *p){
+  if( p->flags & MEM_Null ){
+    fprintf(out, " NULL");
+  }else if( (p->flags & (MEM_Int|MEM_Str))==(MEM_Int|MEM_Str) ){
+    fprintf(out, " si:%lld", p->u.i);
+  }else if( p->flags & MEM_Int ){
+    fprintf(out, " i:%lld", p->u.i);
+  }else if( p->flags & MEM_Real ){
+    fprintf(out, " r:%g", p->r);
+  }else{
+    char zBuf[200];
+    sqlite3VdbeMemPrettyPrint(p, zBuf);
+    fprintf(out, " ");
+    fprintf(out, "%s", zBuf);
+  }
+}
+static void registerTrace(FILE *out, int iReg, Mem *p){
+  fprintf(out, "REG[%d] = ", iReg);
+  memTracePrint(out, p);
+  fprintf(out, "\n");
+}
+#endif
+
+#ifdef SQLITE_DEBUG
+#  define REGISTER_TRACE(R,M) if(p->trace)registerTrace(p->trace,R,M)
+#else
+#  define REGISTER_TRACE(R,M)
+#endif
+
+
+#ifdef VDBE_PROFILE
+
+/* 
+** hwtime.h contains inline assembler code for implementing 
+** high-performance timing routines.
+*/
+#include "hwtime.h"
+
+#endif
+
+/*
+** The CHECK_FOR_INTERRUPT macro defined here looks to see if the
+** sqlite3_interrupt() routine has been called.  If it has been, then
+** processing of the VDBE program is interrupted.
+**
+** This macro added to every instruction that does a jump in order to
+** implement a loop.  This test used to be on every single instruction,
+** but that meant we more testing that we needed.  By only testing the
+** flag on jump instructions, we get a (small) speed improvement.
+*/
+#define CHECK_FOR_INTERRUPT \
+   if( db->u1.isInterrupted ) goto abort_due_to_interrupt;
+
+#ifdef SQLITE_DEBUG
+static int fileExists(sqlite3 *db, const char *zFile){
+  int res = 0;
+  int rc = SQLITE_OK;
+#ifdef SQLITE_TEST
+  /* If we are currently testing IO errors, then do not call OsAccess() to
+  ** test for the presence of zFile. This is because any IO error that
+  ** occurs here will not be reported, causing the test to fail.
+  */
+  extern int sqlite3_io_error_pending;
+  if( sqlite3_io_error_pending<=0 )
+#endif
+    rc = sqlite3OsAccess(db->pVfs, zFile, SQLITE_ACCESS_EXISTS, &res);
+  return (res && rc==SQLITE_OK);
+}
+#endif
+
+/*
+** Execute as much of a VDBE program as we can then return.
+**
+** sqlite3VdbeMakeReady() must be called before this routine in order to
+** close the program with a final OP_Halt and to set up the callbacks
+** and the error message pointer.
+**
+** Whenever a row or result data is available, this routine will either
+** invoke the result callback (if there is one) or return with
+** SQLITE_ROW.
+**
+** If an attempt is made to open a locked database, then this routine
+** will either invoke the busy callback (if there is one) or it will
+** return SQLITE_BUSY.
+**
+** If an error occurs, an error message is written to memory obtained
+** from sqlite3_malloc() and p->zErrMsg is made to point to that memory.
+** The error code is stored in p->rc and this routine returns SQLITE_ERROR.
+**
+** If the callback ever returns non-zero, then the program exits
+** immediately.  There will be no error message but the p->rc field is
+** set to SQLITE_ABORT and this routine will return SQLITE_ERROR.
+**
+** A memory allocation error causes p->rc to be set to SQLITE_NOMEM and this
+** routine to return SQLITE_ERROR.
+**
+** Other fatal errors return SQLITE_ERROR.
+**
+** After this routine has finished, sqlite3VdbeFinalize() should be
+** used to clean up the mess that was left behind.
+*/
+int sqlite3VdbeExec(
+  Vdbe *p                    /* The VDBE */
+){
+  int pc;                    /* The program counter */
+  Op *pOp;                   /* Current operation */
+  int rc = SQLITE_OK;        /* Value to return */
+  sqlite3 *db = p->db;       /* The database */
+  u8 encoding = ENC(db);     /* The database encoding */
+  Mem *pIn1, *pIn2, *pIn3;   /* Input operands */
+  Mem *pOut;                 /* Output operand */
+  u8 opProperty;
+  int iCompare = 0;          /* Result of last OP_Compare operation */
+  int *aPermute = 0;         /* Permuation of columns for OP_Compare */
+#ifdef VDBE_PROFILE
+  u64 start;                 /* CPU clock count at start of opcode */
+  int origPc;                /* Program counter at start of opcode */
+#endif
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+  int nProgressOps = 0;      /* Opcodes executed since progress callback. */
+#endif
+
+  assert( p->magic==VDBE_MAGIC_RUN );  /* sqlite3_step() verifies this */
+  assert( db->magic==SQLITE_MAGIC_BUSY );
+  sqlite3BtreeMutexArrayEnter(&p->aMutex);
+  if( p->rc==SQLITE_NOMEM ){
+    /* This happens if a malloc() inside a call to sqlite3_column_text() or
+    ** sqlite3_column_text16() failed.  */
+    goto no_mem;
+  }
+  assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY );
+  p->rc = SQLITE_OK;
+  assert( p->explain==0 );
+  p->pResultSet = 0;
+  db->busyHandler.nBusy = 0;
+  CHECK_FOR_INTERRUPT;
+  sqlite3VdbeIOTraceSql(p);
+#ifdef SQLITE_DEBUG
+  sqlite3BeginBenignMalloc();
+  if( p->pc==0 
+   && ((p->db->flags & SQLITE_VdbeListing) || fileExists(db, "vdbe_explain"))
+  ){
+    int i;
+    printf("VDBE Program Listing:\n");
+    sqlite3VdbePrintSql(p);
+    for(i=0; i<p->nOp; i++){
+      sqlite3VdbePrintOp(stdout, i, &p->aOp[i]);
+    }
+  }
+  if( fileExists(db, "vdbe_trace") ){
+    p->trace = stdout;
+  }
+  sqlite3EndBenignMalloc();
+#endif
+  for(pc=p->pc; rc==SQLITE_OK; pc++){
+    assert( pc>=0 && pc<p->nOp );
+    if( db->mallocFailed ) goto no_mem;
+#ifdef VDBE_PROFILE
+    origPc = pc;
+    start = sqlite3Hwtime();
+#endif
+    pOp = &p->aOp[pc];
+
+    /* Only allow tracing if SQLITE_DEBUG is defined.
+    */
+#ifdef SQLITE_DEBUG
+    if( p->trace ){
+      if( pc==0 ){
+        printf("VDBE Execution Trace:\n");
+        sqlite3VdbePrintSql(p);
+      }
+      sqlite3VdbePrintOp(p->trace, pc, pOp);
+    }
+    if( p->trace==0 && pc==0 ){
+      sqlite3BeginBenignMalloc();
+      if( fileExists(db, "vdbe_sqltrace") ){
+        sqlite3VdbePrintSql(p);
+      }
+      sqlite3EndBenignMalloc();
+    }
+#endif
+      
+
+    /* Check to see if we need to simulate an interrupt.  This only happens
+    ** if we have a special test build.
+    */
+#ifdef SQLITE_TEST
+    if( sqlite3_interrupt_count>0 ){
+      sqlite3_interrupt_count--;
+      if( sqlite3_interrupt_count==0 ){
+        sqlite3_interrupt(db);
+      }
+    }
+#endif
+
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+    /* Call the progress callback if it is configured and the required number
+    ** of VDBE ops have been executed (either since this invocation of
+    ** sqlite3VdbeExec() or since last time the progress callback was called).
+    ** If the progress callback returns non-zero, exit the virtual machine with
+    ** a return code SQLITE_ABORT.
+    */
+    if( db->xProgress ){
+      if( db->nProgressOps==nProgressOps ){
+        int prc;
+        if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+        prc =db->xProgress(db->pProgressArg);
+        if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+        if( prc!=0 ){
+          rc = SQLITE_INTERRUPT;
+          goto vdbe_error_halt;
+        }
+        nProgressOps = 0;
+      }
+      nProgressOps++;
+    }
+#endif
+
+    /* Do common setup processing for any opcode that is marked
+    ** with the "out2-prerelease" tag.  Such opcodes have a single
+    ** output which is specified by the P2 parameter.  The P2 register
+    ** is initialized to a NULL.
+    */
+    opProperty = opcodeProperty[pOp->opcode];
+    if( (opProperty & OPFLG_OUT2_PRERELEASE)!=0 ){
+      assert( pOp->p2>0 );
+      assert( pOp->p2<=p->nMem );
+      pOut = &p->aMem[pOp->p2];
+      sqlite3VdbeMemReleaseExternal(pOut);
+      pOut->flags = MEM_Null;
+    }else
+ 
+    /* Do common setup for opcodes marked with one of the following
+    ** combinations of properties.
+    **
+    **           in1
+    **           in1 in2
+    **           in1 in2 out3
+    **           in1 in3
+    **
+    ** Variables pIn1, pIn2, and pIn3 are made to point to appropriate
+    ** registers for inputs.  Variable pOut points to the output register.
+    */
+    if( (opProperty & OPFLG_IN1)!=0 ){
+      assert( pOp->p1>0 );
+      assert( pOp->p1<=p->nMem );
+      pIn1 = &p->aMem[pOp->p1];
+      REGISTER_TRACE(pOp->p1, pIn1);
+      if( (opProperty & OPFLG_IN2)!=0 ){
+        assert( pOp->p2>0 );
+        assert( pOp->p2<=p->nMem );
+        pIn2 = &p->aMem[pOp->p2];
+        REGISTER_TRACE(pOp->p2, pIn2);
+        if( (opProperty & OPFLG_OUT3)!=0 ){
+          assert( pOp->p3>0 );
+          assert( pOp->p3<=p->nMem );
+          pOut = &p->aMem[pOp->p3];
+        }
+      }else if( (opProperty & OPFLG_IN3)!=0 ){
+        assert( pOp->p3>0 );
+        assert( pOp->p3<=p->nMem );
+        pIn3 = &p->aMem[pOp->p3];
+        REGISTER_TRACE(pOp->p3, pIn3);
+      }
+    }else if( (opProperty & OPFLG_IN2)!=0 ){
+      assert( pOp->p2>0 );
+      assert( pOp->p2<=p->nMem );
+      pIn2 = &p->aMem[pOp->p2];
+      REGISTER_TRACE(pOp->p2, pIn2);
+    }else if( (opProperty & OPFLG_IN3)!=0 ){
+      assert( pOp->p3>0 );
+      assert( pOp->p3<=p->nMem );
+      pIn3 = &p->aMem[pOp->p3];
+      REGISTER_TRACE(pOp->p3, pIn3);
+    }
+
+    switch( pOp->opcode ){
+
+/*****************************************************************************
+** What follows is a massive switch statement where each case implements a
+** separate instruction in the virtual machine.  If we follow the usual
+** indentation conventions, each case should be indented by 6 spaces.  But
+** that is a lot of wasted space on the left margin.  So the code within
+** the switch statement will break with convention and be flush-left. Another
+** big comment (similar to this one) will mark the point in the code where
+** we transition back to normal indentation.
+**
+** The formatting of each case is important.  The makefile for SQLite
+** generates two C files "opcodes.h" and "opcodes.c" by scanning this
+** file looking for lines that begin with "case OP_".  The opcodes.h files
+** will be filled with #defines that give unique integer values to each
+** opcode and the opcodes.c file is filled with an array of strings where
+** each string is the symbolic name for the corresponding opcode.  If the
+** case statement is followed by a comment of the form "/# same as ... #/"
+** that comment is used to determine the particular value of the opcode.
+**
+** Other keywords in the comment that follows each case are used to
+** construct the OPFLG_INITIALIZER value that initializes opcodeProperty[].
+** Keywords include: in1, in2, in3, out2_prerelease, out2, out3.  See
+** the mkopcodeh.awk script for additional information.
+**
+** Documentation about VDBE opcodes is generated by scanning this file
+** for lines of that contain "Opcode:".  That line and all subsequent
+** comment lines are used in the generation of the opcode.html documentation
+** file.
+**
+** SUMMARY:
+**
+**     Formatting is important to scripts that scan this file.
+**     Do not deviate from the formatting style currently in use.
+**
+*****************************************************************************/
+
+/* Opcode:  Goto * P2 * * *
+**
+** An unconditional jump to address P2.
+** The next instruction executed will be 
+** the one at index P2 from the beginning of
+** the program.
+*/
+case OP_Goto: {             /* jump */
+  CHECK_FOR_INTERRUPT;
+  pc = pOp->p2 - 1;
+  break;
+}
+
+/* Opcode:  Gosub P1 P2 * * *
+**
+** Write the current address onto register P1
+** and then jump to address P2.
+*/
+case OP_Gosub: {            /* jump */
+  assert( pOp->p1>0 );
+  assert( pOp->p1<=p->nMem );
+  pIn1 = &p->aMem[pOp->p1];
+  assert( (pIn1->flags & MEM_Dyn)==0 );
+  pIn1->flags = MEM_Int;
+  pIn1->u.i = pc;
+  REGISTER_TRACE(pOp->p1, pIn1);
+  pc = pOp->p2 - 1;
+  break;
+}
+
+/* Opcode:  Return P1 * * * *
+**
+** Jump to the next instruction after the address in register P1.
+*/
+case OP_Return: {           /* in1 */
+  assert( pIn1->flags & MEM_Int );
+  pc = pIn1->u.i;
+  break;
+}
+
+/* Opcode:  Yield P1 * * * *
+**
+** Swap the program counter with the value in register P1.
+*/
+case OP_Yield: {
+  int pcDest;
+  assert( pOp->p1>0 );
+  assert( pOp->p1<=p->nMem );
+  pIn1 = &p->aMem[pOp->p1];
+  assert( (pIn1->flags & MEM_Dyn)==0 );
+  pIn1->flags = MEM_Int;
+  pcDest = pIn1->u.i;
+  pIn1->u.i = pc;
+  REGISTER_TRACE(pOp->p1, pIn1);
+  pc = pcDest;
+  break;
+}
+
+
+/* Opcode:  Halt P1 P2 * P4 *
+**
+** Exit immediately.  All open cursors, Fifos, etc are closed
+** automatically.
+**
+** P1 is the result code returned by sqlite3_exec(), sqlite3_reset(),
+** or sqlite3_finalize().  For a normal halt, this should be SQLITE_OK (0).
+** For errors, it can be some other value.  If P1!=0 then P2 will determine
+** whether or not to rollback the current transaction.  Do not rollback
+** if P2==OE_Fail. Do the rollback if P2==OE_Rollback.  If P2==OE_Abort,
+** then back out all changes that have occurred during this execution of the
+** VDBE, but do not rollback the transaction. 
+**
+** If P4 is not null then it is an error message string.
+**
+** There is an implied "Halt 0 0 0" instruction inserted at the very end of
+** every program.  So a jump past the last instruction of the program
+** is the same as executing Halt.
+*/
+case OP_Halt: {
+  p->rc = pOp->p1;
+  p->pc = pc;
+  p->errorAction = pOp->p2;
+  if( pOp->p4.z ){
+    sqlite3SetString(&p->zErrMsg, db, "%s", pOp->p4.z);
+  }
+  rc = sqlite3VdbeHalt(p);
+  assert( rc==SQLITE_BUSY || rc==SQLITE_OK );
+  if( rc==SQLITE_BUSY ){
+    p->rc = rc = SQLITE_BUSY;
+  }else{
+    rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;
+  }
+  goto vdbe_return;
+}
+
+/* Opcode: Integer P1 P2 * * *
+**
+** The 32-bit integer value P1 is written into register P2.
+*/
+case OP_Integer: {         /* out2-prerelease */
+  pOut->flags = MEM_Int;
+  pOut->u.i = pOp->p1;
+  break;
+}
+
+/* Opcode: Int64 * P2 * P4 *
+**
+** P4 is a pointer to a 64-bit integer value.
+** Write that value into register P2.
+*/
+case OP_Int64: {           /* out2-prerelease */
+  assert( pOp->p4.pI64!=0 );
+  pOut->flags = MEM_Int;
+  pOut->u.i = *pOp->p4.pI64;
+  break;
+}
+
+/* Opcode: Real * P2 * P4 *
+**
+** P4 is a pointer to a 64-bit floating point value.
+** Write that value into register P2.
+*/
+case OP_Real: {            /* same as TK_FLOAT, out2-prerelease */
+  pOut->flags = MEM_Real;
+  assert( !sqlite3IsNaN(*pOp->p4.pReal) );
+  pOut->r = *pOp->p4.pReal;
+  break;
+}
+
+/* Opcode: String8 * P2 * P4 *
+**
+** P4 points to a nul terminated UTF-8 string. This opcode is transformed 
+** into an OP_String before it is executed for the first time.
+*/
+case OP_String8: {         /* same as TK_STRING, out2-prerelease */
+  assert( pOp->p4.z!=0 );
+  pOp->opcode = OP_String;
+  pOp->p1 = strlen(pOp->p4.z);
+
+#ifndef SQLITE_OMIT_UTF16
+  if( encoding!=SQLITE_UTF8 ){
+    sqlite3VdbeMemSetStr(pOut, pOp->p4.z, -1, SQLITE_UTF8, SQLITE_STATIC);
+    if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pOut, encoding) ) goto no_mem;
+    if( SQLITE_OK!=sqlite3VdbeMemMakeWriteable(pOut) ) goto no_mem;
+    pOut->zMalloc = 0;
+    pOut->flags |= MEM_Static;
+    pOut->flags &= ~MEM_Dyn;
+    if( pOp->p4type==P4_DYNAMIC ){
+      sqlite3DbFree(db, pOp->p4.z);
+    }
+    pOp->p4type = P4_DYNAMIC;
+    pOp->p4.z = pOut->z;
+    pOp->p1 = pOut->n;
+    if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+      goto too_big;
+    }
+    UPDATE_MAX_BLOBSIZE(pOut);
+    break;
+  }
+#endif
+  if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    goto too_big;
+  }
+  /* Fall through to the next case, OP_String */
+}
+  
+/* Opcode: String P1 P2 * P4 *
+**
+** The string value P4 of length P1 (bytes) is stored in register P2.
+*/
+case OP_String: {          /* out2-prerelease */
+  assert( pOp->p4.z!=0 );
+  pOut->flags = MEM_Str|MEM_Static|MEM_Term;
+  pOut->z = pOp->p4.z;
+  pOut->n = pOp->p1;
+  pOut->enc = encoding;
+  UPDATE_MAX_BLOBSIZE(pOut);
+  break;
+}
+
+/* Opcode: Null * P2 * * *
+**
+** Write a NULL into register P2.
+*/
+case OP_Null: {           /* out2-prerelease */
+  break;
+}
+
+
+#ifndef SQLITE_OMIT_BLOB_LITERAL
+/* Opcode: Blob P1 P2 * P4
+**
+** P4 points to a blob of data P1 bytes long.  Store this
+** blob in register P2. This instruction is not coded directly
+** by the compiler. Instead, the compiler layer specifies
+** an OP_HexBlob opcode, with the hex string representation of
+** the blob as P4. This opcode is transformed to an OP_Blob
+** the first time it is executed.
+*/
+case OP_Blob: {                /* out2-prerelease */
+  assert( pOp->p1 <= SQLITE_MAX_LENGTH );
+  sqlite3VdbeMemSetStr(pOut, pOp->p4.z, pOp->p1, 0, 0);
+  pOut->enc = encoding;
+  UPDATE_MAX_BLOBSIZE(pOut);
+  break;
+}
+#endif /* SQLITE_OMIT_BLOB_LITERAL */
+
+/* Opcode: Variable P1 P2 * * *
+**
+** The value of variable P1 is written into register P2. A variable is
+** an unknown in the original SQL string as handed to sqlite3_compile().
+** Any occurrence of the '?' character in the original SQL is considered
+** a variable.  Variables in the SQL string are number from left to
+** right beginning with 1.  The values of variables are set using the
+** sqlite3_bind() API.
+*/
+case OP_Variable: {           /* out2-prerelease */
+  int j = pOp->p1 - 1;
+  Mem *pVar;
+  assert( j>=0 && j<p->nVar );
+
+  pVar = &p->aVar[j];
+  if( sqlite3VdbeMemTooBig(pVar) ){
+    goto too_big;
+  }
+  sqlite3VdbeMemShallowCopy(pOut, &p->aVar[j], MEM_Static);
+  UPDATE_MAX_BLOBSIZE(pOut);
+  break;
+}
+
+/* Opcode: Move P1 P2 P3 * *
+**
+** Move the values in register P1..P1+P3-1 over into
+** registers P2..P2+P3-1.  Registers P1..P1+P1-1 are
+** left holding a NULL.  It is an error for register ranges
+** P1..P1+P3-1 and P2..P2+P3-1 to overlap.
+*/
+case OP_Move: {
+  char *zMalloc;
+  int n = pOp->p3;
+  int p1 = pOp->p1;
+  int p2 = pOp->p2;
+  assert( n>0 );
+  assert( p1>0 );
+  assert( p1+n<p->nMem );
+  pIn1 = &p->aMem[p1];
+  assert( p2>0 );
+  assert( p2+n<p->nMem );
+  pOut = &p->aMem[p2];
+  assert( p1+n<=p2 || p2+n<=p1 );
+  while( n-- ){
+    zMalloc = pOut->zMalloc;
+    pOut->zMalloc = 0;
+    sqlite3VdbeMemMove(pOut, pIn1);
+    pIn1->zMalloc = zMalloc;
+    REGISTER_TRACE(p2++, pOut);
+    pIn1++;
+    pOut++;
+  }
+  break;
+}
+
+/* Opcode: Copy P1 P2 * * *
+**
+** Make a copy of register P1 into register P2.
+**
+** This instruction makes a deep copy of the value.  A duplicate
+** is made of any string or blob constant.  See also OP_SCopy.
+*/
+case OP_Copy: {
+  assert( pOp->p1>0 );
+  assert( pOp->p1<=p->nMem );
+  pIn1 = &p->aMem[pOp->p1];
+  assert( pOp->p2>0 );
+  assert( pOp->p2<=p->nMem );
+  pOut = &p->aMem[pOp->p2];
+  assert( pOut!=pIn1 );
+  sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
+  Deephemeralize(pOut);
+  REGISTER_TRACE(pOp->p2, pOut);
+  break;
+}
+
+/* Opcode: SCopy P1 P2 * * *
+**
+** Make a shallow copy of register P1 into register P2.
+**
+** This instruction makes a shallow copy of the value.  If the value
+** is a string or blob, then the copy is only a pointer to the
+** original and hence if the original changes so will the copy.
+** Worse, if the original is deallocated, the copy becomes invalid.
+** Thus the program must guarantee that the original will not change
+** during the lifetime of the copy.  Use OP_Copy to make a complete
+** copy.
+*/
+case OP_SCopy: {
+  assert( pOp->p1>0 );
+  assert( pOp->p1<=p->nMem );
+  pIn1 = &p->aMem[pOp->p1];
+  REGISTER_TRACE(pOp->p1, pIn1);
+  assert( pOp->p2>0 );
+  assert( pOp->p2<=p->nMem );
+  pOut = &p->aMem[pOp->p2];
+  assert( pOut!=pIn1 );
+  sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
+  REGISTER_TRACE(pOp->p2, pOut);
+  break;
+}
+
+/* Opcode: ResultRow P1 P2 * * *
+**
+** The registers P1 through P1+P2-1 contain a single row of
+** results. This opcode causes the sqlite3_step() call to terminate
+** with an SQLITE_ROW return code and it sets up the sqlite3_stmt
+** structure to provide access to the top P1 values as the result
+** row.
+*/
+case OP_ResultRow: {
+  Mem *pMem;
+  int i;
+  assert( p->nResColumn==pOp->p2 );
+  assert( pOp->p1>0 );
+  assert( pOp->p1+pOp->p2<=p->nMem );
+
+  /* Invalidate all ephemeral cursor row caches */
+  p->cacheCtr = (p->cacheCtr + 2)|1;
+
+  /* Make sure the results of the current row are \000 terminated
+  ** and have an assigned type.  The results are de-ephemeralized as
+  ** as side effect.
+  */
+  pMem = p->pResultSet = &p->aMem[pOp->p1];
+  for(i=0; i<pOp->p2; i++){
+    sqlite3VdbeMemNulTerminate(&pMem[i]);
+    storeTypeInfo(&pMem[i], encoding);
+    REGISTER_TRACE(pOp->p1+i, &pMem[i]);
+  }
+  if( db->mallocFailed ) goto no_mem;
+
+  /* Return SQLITE_ROW
+  */
+  p->nCallback++;
+  p->pc = pc + 1;
+  rc = SQLITE_ROW;
+  goto vdbe_return;
+}
+
+/* Opcode: Concat P1 P2 P3 * *
+**
+** Add the text in register P1 onto the end of the text in
+** register P2 and store the result in register P3.
+** If either the P1 or P2 text are NULL then store NULL in P3.
+**
+**   P3 = P2 || P1
+**
+** It is illegal for P1 and P3 to be the same register. Sometimes,
+** if P3 is the same register as P2, the implementation is able
+** to avoid a memcpy().
+*/
+case OP_Concat: {           /* same as TK_CONCAT, in1, in2, out3 */
+  i64 nByte;
+
+  assert( pIn1!=pOut );
+  if( (pIn1->flags | pIn2->flags) & MEM_Null ){
+    sqlite3VdbeMemSetNull(pOut);
+    break;
+  }
+  ExpandBlob(pIn1);
+  Stringify(pIn1, encoding);
+  ExpandBlob(pIn2);
+  Stringify(pIn2, encoding);
+  nByte = pIn1->n + pIn2->n;
+  if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    goto too_big;
+  }
+  MemSetTypeFlag(pOut, MEM_Str);
+  if( sqlite3VdbeMemGrow(pOut, nByte+2, pOut==pIn2) ){
+    goto no_mem;
+  }
+  if( pOut!=pIn2 ){
+    memcpy(pOut->z, pIn2->z, pIn2->n);
+  }
+  memcpy(&pOut->z[pIn2->n], pIn1->z, pIn1->n);
+  pOut->z[nByte] = 0;
+  pOut->z[nByte+1] = 0;
+  pOut->flags |= MEM_Term;
+  pOut->n = nByte;
+  pOut->enc = encoding;
+  UPDATE_MAX_BLOBSIZE(pOut);
+  break;
+}
+
+/* Opcode: Add P1 P2 P3 * *
+**
+** Add the value in register P1 to the value in register P2
+** and store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: Multiply P1 P2 P3 * *
+**
+**
+** Multiply the value in register P1 by the value in register P2
+** and store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: Subtract P1 P2 P3 * *
+**
+** Subtract the value in register P1 from the value in register P2
+** and store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: Divide P1 P2 P3 * *
+**
+** Divide the value in register P1 by the value in register P2
+** and store the result in register P3.  If the value in register P2
+** is zero, then the result is NULL.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: Remainder P1 P2 P3 * *
+**
+** Compute the remainder after integer division of the value in
+** register P1 by the value in register P2 and store the result in P3. 
+** If the value in register P2 is zero the result is NULL.
+** If either operand is NULL, the result is NULL.
+*/
+case OP_Add:                   /* same as TK_PLUS, in1, in2, out3 */
+case OP_Subtract:              /* same as TK_MINUS, in1, in2, out3 */
+case OP_Multiply:              /* same as TK_STAR, in1, in2, out3 */
+case OP_Divide:                /* same as TK_SLASH, in1, in2, out3 */
+case OP_Remainder: {           /* same as TK_REM, in1, in2, out3 */
+  int flags;
+  applyNumericAffinity(pIn1);
+  applyNumericAffinity(pIn2);
+  flags = pIn1->flags | pIn2->flags;
+  if( (flags & MEM_Null)!=0 ) goto arithmetic_result_is_null;
+  if( (pIn1->flags & pIn2->flags & MEM_Int)==MEM_Int ){
+    i64 a, b;
+    a = pIn1->u.i;
+    b = pIn2->u.i;
+    switch( pOp->opcode ){
+      case OP_Add:         b += a;       break;
+      case OP_Subtract:    b -= a;       break;
+      case OP_Multiply:    b *= a;       break;
+      case OP_Divide: {
+        if( a==0 ) goto arithmetic_result_is_null;
+        /* Dividing the largest possible negative 64-bit integer (1<<63) by 
+        ** -1 returns an integer too large to store in a 64-bit data-type. On
+        ** some architectures, the value overflows to (1<<63). On others,
+        ** a SIGFPE is issued. The following statement normalizes this
+        ** behavior so that all architectures behave as if integer 
+        ** overflow occurred.
+        */
+        if( a==-1 && b==SMALLEST_INT64 ) a = 1;
+        b /= a;
+        break;
+      }
+      default: {
+        if( a==0 ) goto arithmetic_result_is_null;
+        if( a==-1 ) a = 1;
+        b %= a;
+        break;
+      }
+    }
+    pOut->u.i = b;
+    MemSetTypeFlag(pOut, MEM_Int);
+  }else{
+    double a, b;
+    a = sqlite3VdbeRealValue(pIn1);
+    b = sqlite3VdbeRealValue(pIn2);
+    switch( pOp->opcode ){
+      case OP_Add:         b += a;       break;
+      case OP_Subtract:    b -= a;       break;
+      case OP_Multiply:    b *= a;       break;
+      case OP_Divide: {
+        if( a==0.0 ) goto arithmetic_result_is_null;
+        b /= a;
+        break;
+      }
+      default: {
+        i64 ia = (i64)a;
+        i64 ib = (i64)b;
+        if( ia==0 ) goto arithmetic_result_is_null;
+        if( ia==-1 ) ia = 1;
+        b = ib % ia;
+        break;
+      }
+    }
+    if( sqlite3IsNaN(b) ){
+      goto arithmetic_result_is_null;
+    }
+    pOut->r = b;
+    MemSetTypeFlag(pOut, MEM_Real);
+    if( (flags & MEM_Real)==0 ){
+      sqlite3VdbeIntegerAffinity(pOut);
+    }
+  }
+  break;
+
+arithmetic_result_is_null:
+  sqlite3VdbeMemSetNull(pOut);
+  break;
+}
+
+/* Opcode: CollSeq * * P4
+**
+** P4 is a pointer to a CollSeq struct. If the next call to a user function
+** or aggregate calls sqlite3GetFuncCollSeq(), this collation sequence will
+** be returned. This is used by the built-in min(), max() and nullif()
+** functions.
+**
+** The interface used by the implementation of the aforementioned functions
+** to retrieve the collation sequence set by this opcode is not available
+** publicly, only to user functions defined in func.c.
+*/
+case OP_CollSeq: {
+  assert( pOp->p4type==P4_COLLSEQ );
+  break;
+}
+
+/* Opcode: Function P1 P2 P3 P4 P5
+**
+** Invoke a user function (P4 is a pointer to a Function structure that
+** defines the function) with P5 arguments taken from register P2 and
+** successors.  The result of the function is stored in register P3.
+** Register P3 must not be one of the function inputs.
+**
+** P1 is a 32-bit bitmask indicating whether or not each argument to the 
+** function was determined to be constant at compile time. If the first
+** argument was constant then bit 0 of P1 is set. This is used to determine
+** whether meta data associated with a user function argument using the
+** sqlite3_set_auxdata() API may be safely retained until the next
+** invocation of this opcode.
+**
+** See also: AggStep and AggFinal
+*/
+case OP_Function: {
+  int i;
+  Mem *pArg;
+  sqlite3_context ctx;
+  sqlite3_value **apVal;
+  int n = pOp->p5;
+
+  apVal = p->apArg;
+  assert( apVal || n==0 );
+
+  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=p->nMem) );
+  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
+  pArg = &p->aMem[pOp->p2];
+  for(i=0; i<n; i++, pArg++){
+    apVal[i] = pArg;
+    storeTypeInfo(pArg, encoding);
+    REGISTER_TRACE(pOp->p2, pArg);
+  }
+
+  assert( pOp->p4type==P4_FUNCDEF || pOp->p4type==P4_VDBEFUNC );
+  if( pOp->p4type==P4_FUNCDEF ){
+    ctx.pFunc = pOp->p4.pFunc;
+    ctx.pVdbeFunc = 0;
+  }else{
+    ctx.pVdbeFunc = (VdbeFunc*)pOp->p4.pVdbeFunc;
+    ctx.pFunc = ctx.pVdbeFunc->pFunc;
+  }
+
+  assert( pOp->p3>0 && pOp->p3<=p->nMem );
+  pOut = &p->aMem[pOp->p3];
+  ctx.s.flags = MEM_Null;
+  ctx.s.db = db;
+  ctx.s.xDel = 0;
+  ctx.s.zMalloc = 0;
+
+  /* The output cell may already have a buffer allocated. Move
+  ** the pointer to ctx.s so in case the user-function can use
+  ** the already allocated buffer instead of allocating a new one.
+  */
+  sqlite3VdbeMemMove(&ctx.s, pOut);
+  MemSetTypeFlag(&ctx.s, MEM_Null);
+
+  ctx.isError = 0;
+  if( ctx.pFunc->needCollSeq ){
+    assert( pOp>p->aOp );
+    assert( pOp[-1].p4type==P4_COLLSEQ );
+    assert( pOp[-1].opcode==OP_CollSeq );
+    ctx.pColl = pOp[-1].p4.pColl;
+  }
+  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+  (*ctx.pFunc->xFunc)(&ctx, n, apVal);
+  if( sqlite3SafetyOn(db) ){
+    sqlite3VdbeMemRelease(&ctx.s);
+    goto abort_due_to_misuse;
+  }
+  if( db->mallocFailed ){
+    /* Even though a malloc() has failed, the implementation of the
+    ** user function may have called an sqlite3_result_XXX() function
+    ** to return a value. The following call releases any resources
+    ** associated with such a value.
+    **
+    ** Note: Maybe MemRelease() should be called if sqlite3SafetyOn()
+    ** fails also (the if(...) statement above). But if people are
+    ** misusing sqlite, they have bigger problems than a leaked value.
+    */
+    sqlite3VdbeMemRelease(&ctx.s);
+    goto no_mem;
+  }
+
+  /* If any auxiliary data functions have been called by this user function,
+  ** immediately call the destructor for any non-static values.
+  */
+  if( ctx.pVdbeFunc ){
+    sqlite3VdbeDeleteAuxData(ctx.pVdbeFunc, pOp->p1);
+    pOp->p4.pVdbeFunc = ctx.pVdbeFunc;
+    pOp->p4type = P4_VDBEFUNC;
+  }
+
+  /* If the function returned an error, throw an exception */
+  if( ctx.isError ){
+    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&ctx.s));
+    rc = ctx.isError;
+  }
+
+  /* Copy the result of the function into register P3 */
+  sqlite3VdbeChangeEncoding(&ctx.s, encoding);
+  sqlite3VdbeMemMove(pOut, &ctx.s);
+  if( sqlite3VdbeMemTooBig(pOut) ){
+    goto too_big;
+  }
+  REGISTER_TRACE(pOp->p3, pOut);
+  UPDATE_MAX_BLOBSIZE(pOut);
+  break;
+}
+
+/* Opcode: BitAnd P1 P2 P3 * *
+**
+** Take the bit-wise AND of the values in register P1 and P2 and
+** store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: BitOr P1 P2 P3 * *
+**
+** Take the bit-wise OR of the values in register P1 and P2 and
+** store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: ShiftLeft P1 P2 P3 * *
+**
+** Shift the integer value in register P2 to the left by the
+** number of bits specified by the integer in regiser P1.
+** Store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: ShiftRight P1 P2 P3 * *
+**
+** Shift the integer value in register P2 to the right by the
+** number of bits specified by the integer in register P1.
+** Store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+case OP_BitAnd:                 /* same as TK_BITAND, in1, in2, out3 */
+case OP_BitOr:                  /* same as TK_BITOR, in1, in2, out3 */
+case OP_ShiftLeft:              /* same as TK_LSHIFT, in1, in2, out3 */
+case OP_ShiftRight: {           /* same as TK_RSHIFT, in1, in2, out3 */
+  i64 a, b;
+
+  if( (pIn1->flags | pIn2->flags) & MEM_Null ){
+    sqlite3VdbeMemSetNull(pOut);
+    break;
+  }
+  a = sqlite3VdbeIntValue(pIn2);
+  b = sqlite3VdbeIntValue(pIn1);
+  switch( pOp->opcode ){
+    case OP_BitAnd:      a &= b;     break;
+    case OP_BitOr:       a |= b;     break;
+    case OP_ShiftLeft:   a <<= b;    break;
+    default:  assert( pOp->opcode==OP_ShiftRight );
+                         a >>= b;    break;
+  }
+  pOut->u.i = a;
+  MemSetTypeFlag(pOut, MEM_Int);
+  break;
+}
+
+/* Opcode: AddImm  P1 P2 * * *
+** 
+** Add the constant P2 to the value in register P1.
+** The result is always an integer.
+**
+** To force any register to be an integer, just add 0.
+*/
+case OP_AddImm: {            /* in1 */
+  sqlite3VdbeMemIntegerify(pIn1);
+  pIn1->u.i += pOp->p2;
+  break;
+}
+
+/* Opcode: ForceInt P1 P2 P3 * *
+**
+** Convert value in register P1 into an integer.  If the value 
+** in P1 is not numeric (meaning that is is a NULL or a string that
+** does not look like an integer or floating point number) then
+** jump to P2.  If the value in P1 is numeric then
+** convert it into the least integer that is greater than or equal to its
+** current value if P3==0, or to the least integer that is strictly
+** greater than its current value if P3==1.
+*/
+case OP_ForceInt: {            /* jump, in1 */
+  i64 v;
+  applyAffinity(pIn1, SQLITE_AFF_NUMERIC, encoding);
+  if( (pIn1->flags & (MEM_Int|MEM_Real))==0 ){
+    pc = pOp->p2 - 1;
+    break;
+  }
+  if( pIn1->flags & MEM_Int ){
+    v = pIn1->u.i + (pOp->p3!=0);
+  }else{
+    assert( pIn1->flags & MEM_Real );
+    v = (sqlite3_int64)pIn1->r;
+    if( pIn1->r>(double)v ) v++;
+    if( pOp->p3 && pIn1->r==(double)v ) v++;
+  }
+  pIn1->u.i = v;
+  MemSetTypeFlag(pIn1, MEM_Int);
+  break;
+}
+
+/* Opcode: MustBeInt P1 P2 * * *
+** 
+** Force the value in register P1 to be an integer.  If the value
+** in P1 is not an integer and cannot be converted into an integer
+** without data loss, then jump immediately to P2, or if P2==0
+** raise an SQLITE_MISMATCH exception.
+*/
+case OP_MustBeInt: {            /* jump, in1 */
+  applyAffinity(pIn1, SQLITE_AFF_NUMERIC, encoding);
+  if( (pIn1->flags & MEM_Int)==0 ){
+    if( pOp->p2==0 ){
+      rc = SQLITE_MISMATCH;
+      goto abort_due_to_error;
+    }else{
+      pc = pOp->p2 - 1;
+    }
+  }else{
+    MemSetTypeFlag(pIn1, MEM_Int);
+  }
+  break;
+}
+
+/* Opcode: RealAffinity P1 * * * *
+**
+** If register P1 holds an integer convert it to a real value.
+**
+** This opcode is used when extracting information from a column that
+** has REAL affinity.  Such column values may still be stored as
+** integers, for space efficiency, but after extraction we want them
+** to have only a real value.
+*/
+case OP_RealAffinity: {                  /* in1 */
+  if( pIn1->flags & MEM_Int ){
+    sqlite3VdbeMemRealify(pIn1);
+  }
+  break;
+}
+
+#ifndef SQLITE_OMIT_CAST
+/* Opcode: ToText P1 * * * *
+**
+** Force the value in register P1 to be text.
+** If the value is numeric, convert it to a string using the
+** equivalent of printf().  Blob values are unchanged and
+** are afterwards simply interpreted as text.
+**
+** A NULL value is not changed by this routine.  It remains NULL.
+*/
+case OP_ToText: {                  /* same as TK_TO_TEXT, in1 */
+  if( pIn1->flags & MEM_Null ) break;
+  assert( MEM_Str==(MEM_Blob>>3) );
+  pIn1->flags |= (pIn1->flags&MEM_Blob)>>3;
+  applyAffinity(pIn1, SQLITE_AFF_TEXT, encoding);
+  rc = ExpandBlob(pIn1);
+  assert( pIn1->flags & MEM_Str || db->mallocFailed );
+  pIn1->flags &= ~(MEM_Int|MEM_Real|MEM_Blob);
+  UPDATE_MAX_BLOBSIZE(pIn1);
+  break;
+}
+
+/* Opcode: ToBlob P1 * * * *
+**
+** Force the value in register P1 to be a BLOB.
+** If the value is numeric, convert it to a string first.
+** Strings are simply reinterpreted as blobs with no change
+** to the underlying data.
+**
+** A NULL value is not changed by this routine.  It remains NULL.
+*/
+case OP_ToBlob: {                  /* same as TK_TO_BLOB, in1 */
+  if( pIn1->flags & MEM_Null ) break;
+  if( (pIn1->flags & MEM_Blob)==0 ){
+    applyAffinity(pIn1, SQLITE_AFF_TEXT, encoding);
+    assert( pIn1->flags & MEM_Str || db->mallocFailed );
+  }
+  MemSetTypeFlag(pIn1, MEM_Blob);
+  UPDATE_MAX_BLOBSIZE(pIn1);
+  break;
+}
+
+/* Opcode: ToNumeric P1 * * * *
+**
+** Force the value in register P1 to be numeric (either an
+** integer or a floating-point number.)
+** If the value is text or blob, try to convert it to an using the
+** equivalent of atoi() or atof() and store 0 if no such conversion 
+** is possible.
+**
+** A NULL value is not changed by this routine.  It remains NULL.
+*/
+case OP_ToNumeric: {                  /* same as TK_TO_NUMERIC, in1 */
+  if( (pIn1->flags & (MEM_Null|MEM_Int|MEM_Real))==0 ){
+    sqlite3VdbeMemNumerify(pIn1);
+  }
+  break;
+}
+#endif /* SQLITE_OMIT_CAST */
+
+/* Opcode: ToInt P1 * * * *
+**
+** Force the value in register P1 be an integer.  If
+** The value is currently a real number, drop its fractional part.
+** If the value is text or blob, try to convert it to an integer using the
+** equivalent of atoi() and store 0 if no such conversion is possible.
+**
+** A NULL value is not changed by this routine.  It remains NULL.
+*/
+case OP_ToInt: {                  /* same as TK_TO_INT, in1 */
+  if( (pIn1->flags & MEM_Null)==0 ){
+    sqlite3VdbeMemIntegerify(pIn1);
+  }
+  break;
+}
+
+#ifndef SQLITE_OMIT_CAST
+/* Opcode: ToReal P1 * * * *
+**
+** Force the value in register P1 to be a floating point number.
+** If The value is currently an integer, convert it.
+** If the value is text or blob, try to convert it to an integer using the
+** equivalent of atoi() and store 0.0 if no such conversion is possible.
+**
+** A NULL value is not changed by this routine.  It remains NULL.
+*/
+case OP_ToReal: {                  /* same as TK_TO_REAL, in1 */
+  if( (pIn1->flags & MEM_Null)==0 ){
+    sqlite3VdbeMemRealify(pIn1);
+  }
+  break;
+}
+#endif /* SQLITE_OMIT_CAST */
+
+/* Opcode: Lt P1 P2 P3 P4 P5
+**
+** Compare the values in register P1 and P3.  If reg(P3)<reg(P1) then
+** jump to address P2.  
+**
+** If the SQLITE_JUMPIFNULL bit of P5 is set and either reg(P1) or
+** reg(P3) is NULL then take the jump.  If the SQLITE_JUMPIFNULL 
+** bit is clear then fall thru if either operand is NULL.
+**
+** The SQLITE_AFF_MASK portion of P5 must be an affinity character -
+** SQLITE_AFF_TEXT, SQLITE_AFF_INTEGER, and so forth. An attempt is made 
+** to coerce both inputs according to this affinity before the
+** comparison is made. If the SQLITE_AFF_MASK is 0x00, then numeric
+** affinity is used. Note that the affinity conversions are stored
+** back into the input registers P1 and P3.  So this opcode can cause
+** persistent changes to registers P1 and P3.
+**
+** Once any conversions have taken place, and neither value is NULL, 
+** the values are compared. If both values are blobs then memcmp() is
+** used to determine the results of the comparison.  If both values
+** are text, then the appropriate collating function specified in
+** P4 is  used to do the comparison.  If P4 is not specified then
+** memcmp() is used to compare text string.  If both values are
+** numeric, then a numeric comparison is used. If the two values
+** are of different types, then numbers are considered less than
+** strings and strings are considered less than blobs.
+**
+** If the SQLITE_STOREP2 bit of P5 is set, then do not jump.  Instead,
+** store a boolean result (either 0, or 1, or NULL) in register P2.
+*/
+/* Opcode: Ne P1 P2 P3 P4 P5
+**
+** This works just like the Lt opcode except that the jump is taken if
+** the operands in registers P1 and P3 are not equal.  See the Lt opcode for
+** additional information.
+*/
+/* Opcode: Eq P1 P2 P3 P4 P5
+**
+** This works just like the Lt opcode except that the jump is taken if
+** the operands in registers P1 and P3 are equal.
+** See the Lt opcode for additional information.
+*/
+/* Opcode: Le P1 P2 P3 P4 P5
+**
+** This works just like the Lt opcode except that the jump is taken if
+** the content of register P3 is less than or equal to the content of
+** register P1.  See the Lt opcode for additional information.
+*/
+/* Opcode: Gt P1 P2 P3 P4 P5
+**
+** This works just like the Lt opcode except that the jump is taken if
+** the content of register P3 is greater than the content of
+** register P1.  See the Lt opcode for additional information.
+*/
+/* Opcode: Ge P1 P2 P3 P4 P5
+**
+** This works just like the Lt opcode except that the jump is taken if
+** the content of register P3 is greater than or equal to the content of
+** register P1.  See the Lt opcode for additional information.
+*/
+case OP_Eq:               /* same as TK_EQ, jump, in1, in3 */
+case OP_Ne:               /* same as TK_NE, jump, in1, in3 */
+case OP_Lt:               /* same as TK_LT, jump, in1, in3 */
+case OP_Le:               /* same as TK_LE, jump, in1, in3 */
+case OP_Gt:               /* same as TK_GT, jump, in1, in3 */
+case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
+  int flags;
+  int res;
+  char affinity;
+
+  flags = pIn1->flags|pIn3->flags;
+
+  if( flags&MEM_Null ){
+    /* If either operand is NULL then the result is always NULL.
+    ** The jump is taken if the SQLITE_JUMPIFNULL bit is set.
+    */
+    if( pOp->p5 & SQLITE_STOREP2 ){
+      pOut = &p->aMem[pOp->p2];
+      MemSetTypeFlag(pOut, MEM_Null);
+      REGISTER_TRACE(pOp->p2, pOut);
+    }else if( pOp->p5 & SQLITE_JUMPIFNULL ){
+      pc = pOp->p2-1;
+    }
+    break;
+  }
+
+  affinity = pOp->p5 & SQLITE_AFF_MASK;
+  if( affinity ){
+    applyAffinity(pIn1, affinity, encoding);
+    applyAffinity(pIn3, affinity, encoding);
+  }
+
+  assert( pOp->p4type==P4_COLLSEQ || pOp->p4.pColl==0 );
+  ExpandBlob(pIn1);
+  ExpandBlob(pIn3);
+  res = sqlite3MemCompare(pIn3, pIn1, pOp->p4.pColl);
+  switch( pOp->opcode ){
+    case OP_Eq:    res = res==0;     break;
+    case OP_Ne:    res = res!=0;     break;
+    case OP_Lt:    res = res<0;      break;
+    case OP_Le:    res = res<=0;     break;
+    case OP_Gt:    res = res>0;      break;
+    default:       res = res>=0;     break;
+  }
+
+  if( pOp->p5 & SQLITE_STOREP2 ){
+    pOut = &p->aMem[pOp->p2];
+    MemSetTypeFlag(pOut, MEM_Int);
+    pOut->u.i = res;
+    REGISTER_TRACE(pOp->p2, pOut);
+  }else if( res ){
+    pc = pOp->p2-1;
+  }
+  break;
+}
+
+/* Opcode: Permutation * * * P4 *
+**
+** Set the permuation used by the OP_Compare operator to be the array
+** of integers in P4.
+**
+** The permutation is only valid until the next OP_Permutation, OP_Compare,
+** OP_Halt, or OP_ResultRow.  Typically the OP_Permutation should occur
+** immediately prior to the OP_Compare.
+*/
+case OP_Permutation: {
+  assert( pOp->p4type==P4_INTARRAY );
+  assert( pOp->p4.ai );
+  aPermute = pOp->p4.ai;
+  break;
+}
+
+/* Opcode: Compare P1 P2 P3 P4 *
+**
+** Compare to vectors of registers in reg(P1)..reg(P1+P3-1) (all this
+** one "A") and in reg(P2)..reg(P2+P3-1) ("B").  Save the result of
+** the comparison for use by the next OP_Jump instruct.
+**
+** P4 is a KeyInfo structure that defines collating sequences and sort
+** orders for the comparison.  The permutation applies to registers
+** only.  The KeyInfo elements are used sequentially.
+**
+** The comparison is a sort comparison, so NULLs compare equal,
+** NULLs are less than numbers, numbers are less than strings,
+** and strings are less than blobs.
+*/
+case OP_Compare: {
+  int n = pOp->p3;
+  int i, p1, p2;
+  const KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
+  assert( n>0 );
+  assert( pKeyInfo!=0 );
+  p1 = pOp->p1;
+  assert( p1>0 && p1+n-1<p->nMem );
+  p2 = pOp->p2;
+  assert( p2>0 && p2+n-1<p->nMem );
+  for(i=0; i<n; i++){
+    int idx = aPermute ? aPermute[i] : i;
+    CollSeq *pColl;    /* Collating sequence to use on this term */
+    int bRev;          /* True for DESCENDING sort order */
+    REGISTER_TRACE(p1+idx, &p->aMem[p1+idx]);
+    REGISTER_TRACE(p2+idx, &p->aMem[p2+idx]);
+    assert( i<pKeyInfo->nField );
+    pColl = pKeyInfo->aColl[i];
+    bRev = pKeyInfo->aSortOrder[i];
+    iCompare = sqlite3MemCompare(&p->aMem[p1+idx], &p->aMem[p2+idx], pColl);
+    if( iCompare ){
+      if( bRev ) iCompare = -iCompare;
+      break;
+    }
+  }
+  aPermute = 0;
+  break;
+}
+
+/* Opcode: Jump P1 P2 P3 * *
+**
+** Jump to the instruction at address P1, P2, or P3 depending on whether
+** in the most recent OP_Compare instruction the P1 vector was less than
+** equal to, or greater than the P2 vector, respectively.
+*/
+case OP_Jump: {             /* jump */
+  if( iCompare<0 ){
+    pc = pOp->p1 - 1;
+  }else if( iCompare==0 ){
+    pc = pOp->p2 - 1;
+  }else{
+    pc = pOp->p3 - 1;
+  }
+  break;
+}
+
+/* Opcode: And P1 P2 P3 * *
+**
+** Take the logical AND of the values in registers P1 and P2 and
+** write the result into register P3.
+**
+** If either P1 or P2 is 0 (false) then the result is 0 even if
+** the other input is NULL.  A NULL and true or two NULLs give
+** a NULL output.
+*/
+/* Opcode: Or P1 P2 P3 * *
+**
+** Take the logical OR of the values in register P1 and P2 and
+** store the answer in register P3.
+**
+** If either P1 or P2 is nonzero (true) then the result is 1 (true)
+** even if the other input is NULL.  A NULL and false or two NULLs
+** give a NULL output.
+*/
+case OP_And:              /* same as TK_AND, in1, in2, out3 */
+case OP_Or: {             /* same as TK_OR, in1, in2, out3 */
+  int v1, v2;    /* 0==FALSE, 1==TRUE, 2==UNKNOWN or NULL */
+
+  if( pIn1->flags & MEM_Null ){
+    v1 = 2;
+  }else{
+    v1 = sqlite3VdbeIntValue(pIn1)!=0;
+  }
+  if( pIn2->flags & MEM_Null ){
+    v2 = 2;
+  }else{
+    v2 = sqlite3VdbeIntValue(pIn2)!=0;
+  }
+  if( pOp->opcode==OP_And ){
+    static const unsigned char and_logic[] = { 0, 0, 0, 0, 1, 2, 0, 2, 2 };
+    v1 = and_logic[v1*3+v2];
+  }else{
+    static const unsigned char or_logic[] = { 0, 1, 2, 1, 1, 1, 2, 1, 2 };
+    v1 = or_logic[v1*3+v2];
+  }
+  if( v1==2 ){
+    MemSetTypeFlag(pOut, MEM_Null);
+  }else{
+    pOut->u.i = v1;
+    MemSetTypeFlag(pOut, MEM_Int);
+  }
+  break;
+}
+
+/* Opcode: Not P1 * * * *
+**
+** Interpret the value in register P1 as a boolean value.  Replace it
+** with its complement.  If the value in register P1 is NULL its value
+** is unchanged.
+*/
+case OP_Not: {                /* same as TK_NOT, in1 */
+  if( pIn1->flags & MEM_Null ) break;  /* Do nothing to NULLs */
+  sqlite3VdbeMemIntegerify(pIn1);
+  pIn1->u.i = !pIn1->u.i;
+  assert( pIn1->flags&MEM_Int );
+  break;
+}
+
+/* Opcode: BitNot P1 * * * *
+**
+** Interpret the content of register P1 as an integer.  Replace it
+** with its ones-complement.  If the value is originally NULL, leave
+** it unchanged.
+*/
+case OP_BitNot: {             /* same as TK_BITNOT, in1 */
+  if( pIn1->flags & MEM_Null ) break;  /* Do nothing to NULLs */
+  sqlite3VdbeMemIntegerify(pIn1);
+  pIn1->u.i = ~pIn1->u.i;
+  assert( pIn1->flags&MEM_Int );
+  break;
+}
+
+/* Opcode: If P1 P2 P3 * *
+**
+** Jump to P2 if the value in register P1 is true.  The value is
+** is considered true if it is numeric and non-zero.  If the value
+** in P1 is NULL then take the jump if P3 is true.
+*/
+/* Opcode: IfNot P1 P2 P3 * *
+**
+** Jump to P2 if the value in register P1 is False.  The value is
+** is considered true if it has a numeric value of zero.  If the value
+** in P1 is NULL then take the jump if P3 is true.
+*/
+case OP_If:                 /* jump, in1 */
+case OP_IfNot: {            /* jump, in1 */
+  int c;
+  if( pIn1->flags & MEM_Null ){
+    c = pOp->p3;
+  }else{
+#ifdef SQLITE_OMIT_FLOATING_POINT
+    c = sqlite3VdbeIntValue(pIn1);
+#else
+    c = sqlite3VdbeRealValue(pIn1)!=0.0;
+#endif
+    if( pOp->opcode==OP_IfNot ) c = !c;
+  }
+  if( c ){
+    pc = pOp->p2-1;
+  }
+  break;
+}
+
+/* Opcode: IsNull P1 P2 P3 * *
+**
+** Jump to P2 if the value in register P1 is NULL.  If P3 is greater
+** than zero, then check all values reg(P1), reg(P1+1), 
+** reg(P1+2), ..., reg(P1+P3-1).
+*/
+case OP_IsNull: {            /* same as TK_ISNULL, jump, in1 */
+  int n = pOp->p3;
+  assert( pOp->p3==0 || pOp->p1>0 );
+  do{
+    if( (pIn1->flags & MEM_Null)!=0 ){
+      pc = pOp->p2 - 1;
+      break;
+    }
+    pIn1++;
+  }while( --n > 0 );
+  break;
+}
+
+/* Opcode: NotNull P1 P2 * * *
+**
+** Jump to P2 if the value in register P1 is not NULL.  
+*/
+case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */
+  if( (pIn1->flags & MEM_Null)==0 ){
+    pc = pOp->p2 - 1;
+  }
+  break;
+}
+
+/* Opcode: SetNumColumns * P2 * * *
+**
+** This opcode sets the number of columns for the cursor opened by the
+** following instruction to P2.
+**
+** An OP_SetNumColumns is only useful if it occurs immediately before 
+** one of the following opcodes:
+**
+**     OpenRead
+**     OpenWrite
+**     OpenPseudo
+**
+** If the OP_Column opcode is to be executed on a cursor, then
+** this opcode must be present immediately before the opcode that
+** opens the cursor.
+*/
+case OP_SetNumColumns: {
+  break;
+}
+
+/* Opcode: Column P1 P2 P3 P4 *
+**
+** Interpret the data that cursor P1 points to as a structure built using
+** the MakeRecord instruction.  (See the MakeRecord opcode for additional
+** information about the format of the data.)  Extract the P2-th column
+** from this record.  If there are less that (P2+1) 
+** values in the record, extract a NULL.
+**
+** The value extracted is stored in register P3.
+**
+** If the KeyAsData opcode has previously executed on this cursor, then the
+** field might be extracted from the key rather than the data.
+**
+** If the column contains fewer than P2 fields, then extract a NULL.  Or,
+** if the P4 argument is a P4_MEM use the value of the P4 argument as
+** the result.
+*/
+case OP_Column: {
+  u32 payloadSize;   /* Number of bytes in the record */
+  int p1 = pOp->p1;  /* P1 value of the opcode */
+  int p2 = pOp->p2;  /* column number to retrieve */
+  Cursor *pC = 0;    /* The VDBE cursor */
+  char *zRec;        /* Pointer to complete record-data */
+  BtCursor *pCrsr;   /* The BTree cursor */
+  u32 *aType;        /* aType[i] holds the numeric type of the i-th column */
+  u32 *aOffset;      /* aOffset[i] is offset to start of data for i-th column */
+  u32 nField;        /* number of fields in the record */
+  int len;           /* The length of the serialized data for the column */
+  int i;             /* Loop counter */
+  char *zData;       /* Part of the record being decoded */
+  Mem *pDest;        /* Where to write the extracted value */
+  Mem sMem;          /* For storing the record being decoded */
+
+  sMem.flags = 0;
+  sMem.db = 0;
+  sMem.zMalloc = 0;
+  assert( p1<p->nCursor );
+  assert( pOp->p3>0 && pOp->p3<=p->nMem );
+  pDest = &p->aMem[pOp->p3];
+  MemSetTypeFlag(pDest, MEM_Null);
+
+  /* This block sets the variable payloadSize to be the total number of
+  ** bytes in the record.
+  **
+  ** zRec is set to be the complete text of the record if it is available.
+  ** The complete record text is always available for pseudo-tables
+  ** If the record is stored in a cursor, the complete record text
+  ** might be available in the  pC->aRow cache.  Or it might not be.
+  ** If the data is unavailable,  zRec is set to NULL.
+  **
+  ** We also compute the number of columns in the record.  For cursors,
+  ** the number of columns is stored in the Cursor.nField element.
+  */
+  pC = p->apCsr[p1];
+  assert( pC!=0 );
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  assert( pC->pVtabCursor==0 );
+#endif
+  if( pC->pCursor!=0 ){
+    /* The record is stored in a B-Tree */
+    rc = sqlite3VdbeCursorMoveto(pC);
+    if( rc ) goto abort_due_to_error;
+    zRec = 0;
+    pCrsr = pC->pCursor;
+    if( pC->nullRow ){
+      payloadSize = 0;
+    }else if( pC->cacheStatus==p->cacheCtr ){
+      payloadSize = pC->payloadSize;
+      zRec = (char*)pC->aRow;
+    }else if( pC->isIndex ){
+      i64 payloadSize64;
+      sqlite3BtreeKeySize(pCrsr, &payloadSize64);
+      payloadSize = payloadSize64;
+    }else{
+      sqlite3BtreeDataSize(pCrsr, &payloadSize);
+    }
+    nField = pC->nField;
+  }else{
+    assert( pC->pseudoTable );
+    /* The record is the sole entry of a pseudo-table */
+    payloadSize = pC->nData;
+    zRec = pC->pData;
+    pC->cacheStatus = CACHE_STALE;
+    assert( payloadSize==0 || zRec!=0 );
+    nField = pC->nField;
+    pCrsr = 0;
+  }
+
+  /* If payloadSize is 0, then just store a NULL */
+  if( payloadSize==0 ){
+    assert( pDest->flags&MEM_Null );
+    goto op_column_out;
+  }
+  if( payloadSize>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    goto too_big;
+  }
+
+  assert( p2<nField );
+
+  /* Read and parse the table header.  Store the results of the parse
+  ** into the record header cache fields of the cursor.
+  */
+  aType = pC->aType;
+  if( pC->cacheStatus==p->cacheCtr ){
+    aOffset = pC->aOffset;
+  }else{
+    u8 *zIdx;        /* Index into header */
+    u8 *zEndHdr;     /* Pointer to first byte after the header */
+    u32 offset;      /* Offset into the data */
+    int szHdrSz;     /* Size of the header size field at start of record */
+    int avail;       /* Number of bytes of available data */
+
+    assert(aType);
+    pC->aOffset = aOffset = &aType[nField];
+    pC->payloadSize = payloadSize;
+    pC->cacheStatus = p->cacheCtr;
+
+    /* Figure out how many bytes are in the header */
+    if( zRec ){
+      zData = zRec;
+    }else{
+      if( pC->isIndex ){
+        zData = (char*)sqlite3BtreeKeyFetch(pCrsr, &avail);
+      }else{
+        zData = (char*)sqlite3BtreeDataFetch(pCrsr, &avail);
+      }
+      /* If KeyFetch()/DataFetch() managed to get the entire payload,
+      ** save the payload in the pC->aRow cache.  That will save us from
+      ** having to make additional calls to fetch the content portion of
+      ** the record.
+      */
+      if( avail>=payloadSize ){
+        zRec = zData;
+        pC->aRow = (u8*)zData;
+      }else{
+        pC->aRow = 0;
+      }
+    }
+    /* The following assert is true in all cases accept when
+    ** the database file has been corrupted externally.
+    **    assert( zRec!=0 || avail>=payloadSize || avail>=9 ); */
+    szHdrSz = getVarint32((u8*)zData, offset);
+
+    /* The KeyFetch() or DataFetch() above are fast and will get the entire
+    ** record header in most cases.  But they will fail to get the complete
+    ** record header if the record header does not fit on a single page
+    ** in the B-Tree.  When that happens, use sqlite3VdbeMemFromBtree() to
+    ** acquire the complete header text.
+    */
+    if( !zRec && avail<offset ){
+      sMem.flags = 0;
+      sMem.db = 0;
+      rc = sqlite3VdbeMemFromBtree(pCrsr, 0, offset, pC->isIndex, &sMem);
+      if( rc!=SQLITE_OK ){
+        goto op_column_out;
+      }
+      zData = sMem.z;
+    }
+    zEndHdr = (u8 *)&zData[offset];
+    zIdx = (u8 *)&zData[szHdrSz];
+
+    /* Scan the header and use it to fill in the aType[] and aOffset[]
+    ** arrays.  aType[i] will contain the type integer for the i-th
+    ** column and aOffset[i] will contain the offset from the beginning
+    ** of the record to the start of the data for the i-th column
+    */
+    for(i=0; i<nField; i++){
+      if( zIdx<zEndHdr ){
+        aOffset[i] = offset;
+        zIdx += getVarint32(zIdx, aType[i]);
+        offset += sqlite3VdbeSerialTypeLen(aType[i]);
+      }else{
+        /* If i is less that nField, then there are less fields in this
+        ** record than SetNumColumns indicated there are columns in the
+        ** table. Set the offset for any extra columns not present in
+        ** the record to 0. This tells code below to store a NULL
+        ** instead of deserializing a value from the record.
+        */
+        aOffset[i] = 0;
+      }
+    }
+    sqlite3VdbeMemRelease(&sMem);
+    sMem.flags = MEM_Null;
+
+    /* If we have read more header data than was contained in the header,
+    ** or if the end of the last field appears to be past the end of the
+    ** record, or if the end of the last field appears to be before the end
+    ** of the record (when all fields present), then we must be dealing 
+    ** with a corrupt database.
+    */
+    if( zIdx>zEndHdr || offset>payloadSize || (zIdx==zEndHdr && offset!=payloadSize) ){
+      rc = SQLITE_CORRUPT_BKPT;
+      goto op_column_out;
+    }
+  }
+
+  /* Get the column information. If aOffset[p2] is non-zero, then 
+  ** deserialize the value from the record. If aOffset[p2] is zero,
+  ** then there are not enough fields in the record to satisfy the
+  ** request.  In this case, set the value NULL or to P4 if P4 is
+  ** a pointer to a Mem object.
+  */
+  if( aOffset[p2] ){
+    assert( rc==SQLITE_OK );
+    if( zRec ){
+      sqlite3VdbeMemReleaseExternal(pDest);
+      sqlite3VdbeSerialGet((u8 *)&zRec[aOffset[p2]], aType[p2], pDest);
+    }else{
+      len = sqlite3VdbeSerialTypeLen(aType[p2]);
+      sqlite3VdbeMemMove(&sMem, pDest);
+      rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, pC->isIndex, &sMem);
+      if( rc!=SQLITE_OK ){
+        goto op_column_out;
+      }
+      zData = sMem.z;
+      sqlite3VdbeSerialGet((u8*)zData, aType[p2], pDest);
+    }
+    pDest->enc = encoding;
+  }else{
+    if( pOp->p4type==P4_MEM ){
+      sqlite3VdbeMemShallowCopy(pDest, pOp->p4.pMem, MEM_Static);
+    }else{
+      assert( pDest->flags&MEM_Null );
+    }
+  }
+
+  /* If we dynamically allocated space to hold the data (in the
+  ** sqlite3VdbeMemFromBtree() call above) then transfer control of that
+  ** dynamically allocated space over to the pDest structure.
+  ** This prevents a memory copy.
+  */
+  if( sMem.zMalloc ){
+    assert( sMem.z==sMem.zMalloc );
+    assert( !(pDest->flags & MEM_Dyn) );
+    assert( !(pDest->flags & (MEM_Blob|MEM_Str)) || pDest->z==sMem.z );
+    pDest->flags &= ~(MEM_Ephem|MEM_Static);
+    pDest->flags |= MEM_Term;
+    pDest->z = sMem.z;
+    pDest->zMalloc = sMem.zMalloc;
+  }
+
+  rc = sqlite3VdbeMemMakeWriteable(pDest);
+
+op_column_out:
+  UPDATE_MAX_BLOBSIZE(pDest);
+  REGISTER_TRACE(pOp->p3, pDest);
+  break;
+}
+
+/* Opcode: Affinity P1 P2 * P4 *
+**
+** Apply affinities to a range of P2 registers starting with P1.
+**
+** P4 is a string that is P2 characters long. The nth character of the
+** string indicates the column affinity that should be used for the nth
+** memory cell in the range.
+*/
+case OP_Affinity: {
+  char *zAffinity = pOp->p4.z;
+  Mem *pData0 = &p->aMem[pOp->p1];
+  Mem *pLast = &pData0[pOp->p2-1];
+  Mem *pRec;
+
+  for(pRec=pData0; pRec<=pLast; pRec++){
+    ExpandBlob(pRec);
+    applyAffinity(pRec, zAffinity[pRec-pData0], encoding);
+  }
+  break;
+}
+
+/* Opcode: MakeRecord P1 P2 P3 P4 *
+**
+** Convert P2 registers beginning with P1 into a single entry
+** suitable for use as a data record in a database table or as a key
+** in an index.  The details of the format are irrelevant as long as
+** the OP_Column opcode can decode the record later.
+** Refer to source code comments for the details of the record
+** format.
+**
+** P4 may be a string that is P2 characters long.  The nth character of the
+** string indicates the column affinity that should be used for the nth
+** field of the index key.
+**
+** The mapping from character to affinity is given by the SQLITE_AFF_
+** macros defined in sqliteInt.h.
+**
+** If P4 is NULL then all index fields have the affinity NONE.
+*/
+case OP_MakeRecord: {
+  /* Assuming the record contains N fields, the record format looks
+  ** like this:
+  **
+  ** ------------------------------------------------------------------------
+  ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 
+  ** ------------------------------------------------------------------------
+  **
+  ** Data(0) is taken from register P1.  Data(1) comes from register P1+1
+  ** and so froth.
+  **
+  ** Each type field is a varint representing the serial type of the 
+  ** corresponding data element (see sqlite3VdbeSerialType()). The
+  ** hdr-size field is also a varint which is the offset from the beginning
+  ** of the record to data0.
+  */
+  u8 *zNewRecord;        /* A buffer to hold the data for the new record */
+  Mem *pRec;             /* The new record */
+  u64 nData = 0;         /* Number of bytes of data space */
+  int nHdr = 0;          /* Number of bytes of header space */
+  u64 nByte = 0;         /* Data space required for this record */
+  int nZero = 0;         /* Number of zero bytes at the end of the record */
+  int nVarint;           /* Number of bytes in a varint */
+  u32 serial_type;       /* Type field */
+  Mem *pData0;           /* First field to be combined into the record */
+  Mem *pLast;            /* Last field of the record */
+  int nField;            /* Number of fields in the record */
+  char *zAffinity;       /* The affinity string for the record */
+  int file_format;       /* File format to use for encoding */
+  int i;                 /* Space used in zNewRecord[] */
+
+  nField = pOp->p1;
+  zAffinity = pOp->p4.z;
+  assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=p->nMem );
+  pData0 = &p->aMem[nField];
+  nField = pOp->p2;
+  pLast = &pData0[nField-1];
+  file_format = p->minWriteFileFormat;
+
+  /* Loop through the elements that will make up the record to figure
+  ** out how much space is required for the new record.
+  */
+  for(pRec=pData0; pRec<=pLast; pRec++){
+    int len;
+    if( zAffinity ){
+      applyAffinity(pRec, zAffinity[pRec-pData0], encoding);
+    }
+    if( pRec->flags&MEM_Zero && pRec->n>0 ){
+      sqlite3VdbeMemExpandBlob(pRec);
+    }
+    serial_type = sqlite3VdbeSerialType(pRec, file_format);
+    len = sqlite3VdbeSerialTypeLen(serial_type);
+    nData += len;
+    nHdr += sqlite3VarintLen(serial_type);
+    if( pRec->flags & MEM_Zero ){
+      /* Only pure zero-filled BLOBs can be input to this Opcode.
+      ** We do not allow blobs with a prefix and a zero-filled tail. */
+      nZero += pRec->u.i;
+    }else if( len ){
+      nZero = 0;
+    }
+  }
+
+  /* Add the initial header varint and total the size */
+  nHdr += nVarint = sqlite3VarintLen(nHdr);
+  if( nVarint<sqlite3VarintLen(nHdr) ){
+    nHdr++;
+  }
+  nByte = nHdr+nData-nZero;
+  if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    goto too_big;
+  }
+
+  /* Make sure the output register has a buffer large enough to store 
+  ** the new record. The output register (pOp->p3) is not allowed to
+  ** be one of the input registers (because the following call to
+  ** sqlite3VdbeMemGrow() could clobber the value before it is used).
+  */
+  assert( pOp->p3<pOp->p1 || pOp->p3>=pOp->p1+pOp->p2 );
+  pOut = &p->aMem[pOp->p3];
+  if( sqlite3VdbeMemGrow(pOut, nByte, 0) ){
+    goto no_mem;
+  }
+  zNewRecord = (u8 *)pOut->z;
+
+  /* Write the record */
+  i = putVarint32(zNewRecord, nHdr);
+  for(pRec=pData0; pRec<=pLast; pRec++){
+    serial_type = sqlite3VdbeSerialType(pRec, file_format);
+    i += putVarint32(&zNewRecord[i], serial_type);      /* serial type */
+  }
+  for(pRec=pData0; pRec<=pLast; pRec++){  /* serial data */
+    i += sqlite3VdbeSerialPut(&zNewRecord[i], nByte-i, pRec, file_format);
+  }
+  assert( i==nByte );
+
+  assert( pOp->p3>0 && pOp->p3<=p->nMem );
+  pOut->n = nByte;
+  pOut->flags = MEM_Blob | MEM_Dyn;
+  pOut->xDel = 0;
+  if( nZero ){
+    pOut->u.i = nZero;
+    pOut->flags |= MEM_Zero;
+  }
+  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever converted to text */
+  REGISTER_TRACE(pOp->p3, pOut);
+  UPDATE_MAX_BLOBSIZE(pOut);
+  break;
+}
+
+/* Opcode: Statement P1 * * * *
+**
+** Begin an individual statement transaction which is part of a larger
+** transaction.  This is needed so that the statement
+** can be rolled back after an error without having to roll back the
+** entire transaction.  The statement transaction will automatically
+** commit when the VDBE halts.
+**
+** If the database connection is currently in autocommit mode (that 
+** is to say, if it is in between BEGIN and COMMIT)
+** and if there are no other active statements on the same database
+** connection, then this operation is a no-op.  No statement transaction
+** is needed since any error can use the normal ROLLBACK process to
+** undo changes.
+**
+** If a statement transaction is started, then a statement journal file
+** will be allocated and initialized.
+**
+** The statement is begun on the database file with index P1.  The main
+** database file has an index of 0 and the file used for temporary tables
+** has an index of 1.
+*/
+case OP_Statement: {
+  if( db->autoCommit==0 || db->activeVdbeCnt>1 ){
+    int i = pOp->p1;
+    Btree *pBt;
+    assert( i>=0 && i<db->nDb );
+    assert( db->aDb[i].pBt!=0 );
+    pBt = db->aDb[i].pBt;
+    assert( sqlite3BtreeIsInTrans(pBt) );
+    assert( (p->btreeMask & (1<<i))!=0 );
+    if( !sqlite3BtreeIsInStmt(pBt) ){
+      rc = sqlite3BtreeBeginStmt(pBt);
+      p->openedStatement = 1;
+    }
+  }
+  break;
+}
+
+/* Opcode: AutoCommit P1 P2 * * *
+**
+** Set the database auto-commit flag to P1 (1 or 0). If P2 is true, roll
+** back any currently active btree transactions. If there are any active
+** VMs (apart from this one), then the COMMIT or ROLLBACK statement fails.
+**
+** This instruction causes the VM to halt.
+*/
+case OP_AutoCommit: {
+  u8 i = pOp->p1;
+  u8 rollback = pOp->p2;
+
+  assert( i==1 || i==0 );
+  assert( i==1 || rollback==0 );
+
+  assert( db->activeVdbeCnt>0 );  /* At least this one VM is active */
+
+  if( db->activeVdbeCnt>1 && i && !db->autoCommit ){
+    /* If this instruction implements a COMMIT or ROLLBACK, other VMs are
+    ** still running, and a transaction is active, return an error indicating
+    ** that the other VMs must complete first. 
+    */
+    sqlite3SetString(&p->zErrMsg, db, "cannot %s transaction - "
+        "SQL statements in progress",
+        rollback ? "rollback" : "commit");
+    rc = SQLITE_ERROR;
+  }else if( i!=db->autoCommit ){
+    if( pOp->p2 ){
+      assert( i==1 );
+      sqlite3RollbackAll(db);
+      db->autoCommit = 1;
+    }else{
+      db->autoCommit = i;
+      if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
+        p->pc = pc;
+        db->autoCommit = 1-i;
+        p->rc = rc = SQLITE_BUSY;
+        goto vdbe_return;
+      }
+    }
+    if( p->rc==SQLITE_OK ){
+      rc = SQLITE_DONE;
+    }else{
+      rc = SQLITE_ERROR;
+    }
+    goto vdbe_return;
+  }else{
+    sqlite3SetString(&p->zErrMsg, db,
+        (!i)?"cannot start a transaction within a transaction":(
+        (rollback)?"cannot rollback - no transaction is active":
+                   "cannot commit - no transaction is active"));
+         
+    rc = SQLITE_ERROR;
+  }
+  break;
+}
+
+/* Opcode: Transaction P1 P2 * * *
+**
+** Begin a transaction.  The transaction ends when a Commit or Rollback
+** opcode is encountered.  Depending on the ON CONFLICT setting, the
+** transaction might also be rolled back if an error is encountered.
+**
+** P1 is the index of the database file on which the transaction is
+** started.  Index 0 is the main database file and index 1 is the
+** file used for temporary tables.  Indices of 2 or more are used for
+** attached databases.
+**
+** If P2 is non-zero, then a write-transaction is started.  A RESERVED lock is
+** obtained on the database file when a write-transaction is started.  No
+** other process can start another write transaction while this transaction is
+** underway.  Starting a write transaction also creates a rollback journal. A
+** write transaction must be started before any changes can be made to the
+** database.  If P2 is 2 or greater then an EXCLUSIVE lock is also obtained
+** on the file.
+**
+** If P2 is zero, then a read-lock is obtained on the database file.
+*/
+case OP_Transaction: {
+  int i = pOp->p1;
+  Btree *pBt;
+
+  assert( i>=0 && i<db->nDb );
+  assert( (p->btreeMask & (1<<i))!=0 );
+  pBt = db->aDb[i].pBt;
+
+  if( pBt ){
+    rc = sqlite3BtreeBeginTrans(pBt, pOp->p2);
+    if( rc==SQLITE_BUSY ){
+      p->pc = pc;
+      p->rc = rc = SQLITE_BUSY;
+      goto vdbe_return;
+    }
+    if( rc!=SQLITE_OK && rc!=SQLITE_READONLY /* && rc!=SQLITE_BUSY */ ){
+      goto abort_due_to_error;
+    }
+  }
+  break;
+}
+
+/* Opcode: ReadCookie P1 P2 P3 * *
+**
+** Read cookie number P3 from database P1 and write it into register P2.
+** P3==0 is the schema version.  P3==1 is the database format.
+** P3==2 is the recommended pager cache size, and so forth.  P1==0 is
+** the main database file and P1==1 is the database file used to store
+** temporary tables.
+**
+** If P1 is negative, then this is a request to read the size of a
+** databases free-list. P3 must be set to 1 in this case. The actual
+** database accessed is ((P1+1)*-1). For example, a P1 parameter of -1
+** corresponds to database 0 ("main"), a P1 of -2 is database 1 ("temp").
+**
+** There must be a read-lock on the database (either a transaction
+** must be started or there must be an open cursor) before
+** executing this instruction.
+*/
+case OP_ReadCookie: {               /* out2-prerelease */
+  int iMeta;
+  int iDb = pOp->p1;
+  int iCookie = pOp->p3;
+
+  assert( pOp->p3<SQLITE_N_BTREE_META );
+  if( iDb<0 ){
+    iDb = (-1*(iDb+1));
+    iCookie *= -1;
+  }
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( db->aDb[iDb].pBt!=0 );
+  assert( (p->btreeMask & (1<<iDb))!=0 );
+  /* The indexing of meta values at the schema layer is off by one from
+  ** the indexing in the btree layer.  The btree considers meta[0] to
+  ** be the number of free pages in the database (a read-only value)
+  ** and meta[1] to be the schema cookie.  The schema layer considers
+  ** meta[1] to be the schema cookie.  So we have to shift the index
+  ** by one in the following statement.
+  */
+  rc = sqlite3BtreeGetMeta(db->aDb[iDb].pBt, 1 + iCookie, (u32 *)&iMeta);
+  pOut->u.i = iMeta;
+  MemSetTypeFlag(pOut, MEM_Int);
+  break;
+}
+
+/* Opcode: SetCookie P1 P2 P3 * *
+**
+** Write the content of register P3 (interpreted as an integer)
+** into cookie number P2 of database P1.
+** P2==0 is the schema version.  P2==1 is the database format.
+** P2==2 is the recommended pager cache size, and so forth.  P1==0 is
+** the main database file and P1==1 is the database file used to store
+** temporary tables.
+**
+** A transaction must be started before executing this opcode.
+*/
+case OP_SetCookie: {       /* in3 */
+  Db *pDb;
+  assert( pOp->p2<SQLITE_N_BTREE_META );
+  assert( pOp->p1>=0 && pOp->p1<db->nDb );
+  assert( (p->btreeMask & (1<<pOp->p1))!=0 );
+  pDb = &db->aDb[pOp->p1];
+  assert( pDb->pBt!=0 );
+  sqlite3VdbeMemIntegerify(pIn3);
+  /* See note about index shifting on OP_ReadCookie */
+  rc = sqlite3BtreeUpdateMeta(pDb->pBt, 1+pOp->p2, (int)pIn3->u.i);
+  if( pOp->p2==0 ){
+    /* When the schema cookie changes, record the new cookie internally */
+    pDb->pSchema->schema_cookie = pIn3->u.i;
+    db->flags |= SQLITE_InternChanges;
+  }else if( pOp->p2==1 ){
+    /* Record changes in the file format */
+    pDb->pSchema->file_format = pIn3->u.i;
+  }
+  if( pOp->p1==1 ){
+    /* Invalidate all prepared statements whenever the TEMP database
+    ** schema is changed.  Ticket #1644 */
+    sqlite3ExpirePreparedStatements(db);
+  }
+  break;
+}
+
+/* Opcode: VerifyCookie P1 P2 *
+**
+** Check the value of global database parameter number 0 (the
+** schema version) and make sure it is equal to P2.  
+** P1 is the database number which is 0 for the main database file
+** and 1 for the file holding temporary tables and some higher number
+** for auxiliary databases.
+**
+** The cookie changes its value whenever the database schema changes.
+** This operation is used to detect when that the cookie has changed
+** and that the current process needs to reread the schema.
+**
+** Either a transaction needs to have been started or an OP_Open needs
+** to be executed (to establish a read lock) before this opcode is
+** invoked.
+*/
+case OP_VerifyCookie: {
+  int iMeta;
+  Btree *pBt;
+  assert( pOp->p1>=0 && pOp->p1<db->nDb );
+  assert( (p->btreeMask & (1<<pOp->p1))!=0 );
+  pBt = db->aDb[pOp->p1].pBt;
+  if( pBt ){
+    rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&iMeta);
+  }else{
+    rc = SQLITE_OK;
+    iMeta = 0;
+  }
+  if( rc==SQLITE_OK && iMeta!=pOp->p2 ){
+    sqlite3DbFree(db, p->zErrMsg);
+    p->zErrMsg = sqlite3DbStrDup(db, "database schema has changed");
+    /* If the schema-cookie from the database file matches the cookie 
+    ** stored with the in-memory representation of the schema, do
+    ** not reload the schema from the database file.
+    **
+    ** If virtual-tables are in use, this is not just an optimization.
+    ** Often, v-tables store their data in other SQLite tables, which
+    ** are queried from within xNext() and other v-table methods using
+    ** prepared queries. If such a query is out-of-date, we do not want to
+    ** discard the database schema, as the user code implementing the
+    ** v-table would have to be ready for the sqlite3_vtab structure itself
+    ** to be invalidated whenever sqlite3_step() is called from within 
+    ** a v-table method.
+    */
+    if( db->aDb[pOp->p1].pSchema->schema_cookie!=iMeta ){
+      sqlite3ResetInternalSchema(db, pOp->p1);
+    }
+
+    sqlite3ExpirePreparedStatements(db);
+    rc = SQLITE_SCHEMA;
+  }
+  break;
+}
+
+/* Opcode: OpenRead P1 P2 P3 P4 P5
+**
+** Open a read-only cursor for the database table whose root page is
+** P2 in a database file.  The database file is determined by P3. 
+** P3==0 means the main database, P3==1 means the database used for 
+** temporary tables, and P3>1 means used the corresponding attached
+** database.  Give the new cursor an identifier of P1.  The P1
+** values need not be contiguous but all P1 values should be small integers.
+** It is an error for P1 to be negative.
+**
+** If P5!=0 then use the content of register P2 as the root page, not
+** the value of P2 itself.
+**
+** There will be a read lock on the database whenever there is an
+** open cursor.  If the database was unlocked prior to this instruction
+** then a read lock is acquired as part of this instruction.  A read
+** lock allows other processes to read the database but prohibits
+** any other process from modifying the database.  The read lock is
+** released when all cursors are closed.  If this instruction attempts
+** to get a read lock but fails, the script terminates with an
+** SQLITE_BUSY error code.
+**
+** The P4 value is a pointer to a KeyInfo structure that defines the
+** content and collating sequence of indices.  P4 is NULL for cursors
+** that are not pointing to indices.
+**
+** See also OpenWrite.
+*/
+/* Opcode: OpenWrite P1 P2 P3 P4 P5
+**
+** Open a read/write cursor named P1 on the table or index whose root
+** page is P2.  Or if P5!=0 use the content of register P2 to find the
+** root page.
+**
+** The P4 value is a pointer to a KeyInfo structure that defines the
+** content and collating sequence of indices.  P4 is NULL for cursors
+** that are not pointing to indices.
+**
+** This instruction works just like OpenRead except that it opens the cursor
+** in read/write mode.  For a given table, there can be one or more read-only
+** cursors or a single read/write cursor but not both.
+**
+** See also OpenRead.
+*/
+case OP_OpenRead:
+case OP_OpenWrite: {
+  int i = pOp->p1;
+  int p2 = pOp->p2;
+  int iDb = pOp->p3;
+  int wrFlag;
+  Btree *pX;
+  Cursor *pCur;
+  Db *pDb;
+  
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( (p->btreeMask & (1<<iDb))!=0 );
+  pDb = &db->aDb[iDb];
+  pX = pDb->pBt;
+  assert( pX!=0 );
+  if( pOp->opcode==OP_OpenWrite ){
+    wrFlag = 1;
+    if( pDb->pSchema->file_format < p->minWriteFileFormat ){
+      p->minWriteFileFormat = pDb->pSchema->file_format;
+    }
+  }else{
+    wrFlag = 0;
+  }
+  if( pOp->p5 ){
+    assert( p2>0 );
+    assert( p2<=p->nMem );
+    pIn2 = &p->aMem[p2];
+    sqlite3VdbeMemIntegerify(pIn2);
+    p2 = pIn2->u.i;
+    assert( p2>=2 );
+  }
+  assert( i>=0 );
+  pCur = allocateCursor(p, i, &pOp[-1], iDb, 1);
+  if( pCur==0 ) goto no_mem;
+  pCur->nullRow = 1;
+  rc = sqlite3BtreeCursor(pX, p2, wrFlag, pOp->p4.p, pCur->pCursor);
+  if( pOp->p4type==P4_KEYINFO ){
+    pCur->pKeyInfo = pOp->p4.pKeyInfo;
+    pCur->pIncrKey = &pCur->pKeyInfo->incrKey;
+    pCur->pKeyInfo->enc = ENC(p->db);
+  }else{
+    pCur->pKeyInfo = 0;
+    pCur->pIncrKey = &pCur->bogusIncrKey;
+  }
+  switch( rc ){
+    case SQLITE_BUSY: {
+      p->pc = pc;
+      p->rc = rc = SQLITE_BUSY;
+      goto vdbe_return;
+    }
+    case SQLITE_OK: {
+      int flags = sqlite3BtreeFlags(pCur->pCursor);
+      /* Sanity checking.  Only the lower four bits of the flags byte should
+      ** be used.  Bit 3 (mask 0x08) is unpredictable.  The lower 3 bits
+      ** (mask 0x07) should be either 5 (intkey+leafdata for tables) or
+      ** 2 (zerodata for indices).  If these conditions are not met it can
+      ** only mean that we are dealing with a corrupt database file
+      */
+      if( (flags & 0xf0)!=0 || ((flags & 0x07)!=5 && (flags & 0x07)!=2) ){
+        rc = SQLITE_CORRUPT_BKPT;
+        goto abort_due_to_error;
+      }
+      pCur->isTable = (flags & BTREE_INTKEY)!=0;
+      pCur->isIndex = (flags & BTREE_ZERODATA)!=0;
+      /* If P4==0 it means we are expected to open a table.  If P4!=0 then
+      ** we expect to be opening an index.  If this is not what happened,
+      ** then the database is corrupt
+      */
+      if( (pCur->isTable && pOp->p4type==P4_KEYINFO)
+       || (pCur->isIndex && pOp->p4type!=P4_KEYINFO) ){
+        rc = SQLITE_CORRUPT_BKPT;
+        goto abort_due_to_error;
+      }
+      break;
+    }
+    case SQLITE_EMPTY: {
+      pCur->isTable = pOp->p4type!=P4_KEYINFO;
+      pCur->isIndex = !pCur->isTable;
+      pCur->pCursor = 0;
+      rc = SQLITE_OK;
+      break;
+    }
+    default: {
+      goto abort_due_to_error;
+    }
+  }
+  break;
+}
+
+/* Opcode: OpenEphemeral P1 P2 * P4 *
+**
+** Open a new cursor P1 to a transient table.
+** The cursor is always opened read/write even if 
+** the main database is read-only.  The transient or virtual
+** table is deleted automatically when the cursor is closed.
+**
+** P2 is the number of columns in the virtual table.
+** The cursor points to a BTree table if P4==0 and to a BTree index
+** if P4 is not 0.  If P4 is not NULL, it points to a KeyInfo structure
+** that defines the format of keys in the index.
+**
+** This opcode was once called OpenTemp.  But that created
+** confusion because the term "temp table", might refer either
+** to a TEMP table at the SQL level, or to a table opened by
+** this opcode.  Then this opcode was call OpenVirtual.  But
+** that created confusion with the whole virtual-table idea.
+*/
+case OP_OpenEphemeral: {
+  int i = pOp->p1;
+  Cursor *pCx;
+  static const int openFlags = 
+      SQLITE_OPEN_READWRITE |
+      SQLITE_OPEN_CREATE |
+      SQLITE_OPEN_EXCLUSIVE |
+      SQLITE_OPEN_DELETEONCLOSE |
+      SQLITE_OPEN_TRANSIENT_DB;
+
+  assert( i>=0 );
+  pCx = allocateCursor(p, i, pOp, -1, 1);
+  if( pCx==0 ) goto no_mem;
+  pCx->nullRow = 1;
+  rc = sqlite3BtreeFactory(db, 0, 1, SQLITE_DEFAULT_TEMP_CACHE_SIZE, openFlags,
+                           &pCx->pBt);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);
+  }
+  if( rc==SQLITE_OK ){
+    /* If a transient index is required, create it by calling
+    ** sqlite3BtreeCreateTable() with the BTREE_ZERODATA flag before
+    ** opening it. If a transient table is required, just use the
+    ** automatically created table with root-page 1 (an INTKEY table).
+    */
+    if( pOp->p4.pKeyInfo ){
+      int pgno;
+      assert( pOp->p4type==P4_KEYINFO );
+      rc = sqlite3BtreeCreateTable(pCx->pBt, &pgno, BTREE_ZERODATA); 
+      if( rc==SQLITE_OK ){
+        assert( pgno==MASTER_ROOT+1 );
+        rc = sqlite3BtreeCursor(pCx->pBt, pgno, 1, 
+                                (KeyInfo*)pOp->p4.z, pCx->pCursor);
+        pCx->pKeyInfo = pOp->p4.pKeyInfo;
+        pCx->pKeyInfo->enc = ENC(p->db);
+        pCx->pIncrKey = &pCx->pKeyInfo->incrKey;
+      }
+      pCx->isTable = 0;
+    }else{
+      rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, 1, 0, pCx->pCursor);
+      pCx->isTable = 1;
+      pCx->pIncrKey = &pCx->bogusIncrKey;
+    }
+  }
+  pCx->isIndex = !pCx->isTable;
+  break;
+}
+
+/* Opcode: OpenPseudo P1 P2 * * *
+**
+** Open a new cursor that points to a fake table that contains a single
+** row of data.  Any attempt to write a second row of data causes the
+** first row to be deleted.  All data is deleted when the cursor is
+** closed.
+**
+** A pseudo-table created by this opcode is useful for holding the
+** NEW or OLD tables in a trigger.  Also used to hold the a single
+** row output from the sorter so that the row can be decomposed into
+** individual columns using the OP_Column opcode.
+**
+** When OP_Insert is executed to insert a row in to the pseudo table,
+** the pseudo-table cursor may or may not make it's own copy of the
+** original row data. If P2 is 0, then the pseudo-table will copy the
+** original row data. Otherwise, a pointer to the original memory cell
+** is stored. In this case, the vdbe program must ensure that the 
+** memory cell containing the row data is not overwritten until the
+** pseudo table is closed (or a new row is inserted into it).
+*/
+case OP_OpenPseudo: {
+  int i = pOp->p1;
+  Cursor *pCx;
+  assert( i>=0 );
+  pCx = allocateCursor(p, i, &pOp[-1], -1, 0);
+  if( pCx==0 ) goto no_mem;
+  pCx->nullRow = 1;
+  pCx->pseudoTable = 1;
+  pCx->ephemPseudoTable = pOp->p2;
+  pCx->pIncrKey = &pCx->bogusIncrKey;
+  pCx->isTable = 1;
+  pCx->isIndex = 0;
+  break;
+}
+
+/* Opcode: Close P1 * * * *
+**
+** Close a cursor previously opened as P1.  If P1 is not
+** currently open, this instruction is a no-op.
+*/
+case OP_Close: {
+  int i = pOp->p1;
+  assert( i>=0 && i<p->nCursor );
+  sqlite3VdbeFreeCursor(p, p->apCsr[i]);
+  p->apCsr[i] = 0;
+  break;
+}
+
+/* Opcode: MoveGe P1 P2 P3 P4 *
+**
+** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
+** use the integer value in register P3 as a key. If cursor P1 refers 
+** to an SQL index, then P3 is the first in an array of P4 registers 
+** that are used as an unpacked index key. 
+**
+** Reposition cursor P1 so that  it points to the smallest entry that 
+** is greater than or equal to the key value. If there are no records 
+** greater than or equal to the key and P2 is not zero, then jump to P2.
+**
+** A special feature of this opcode (and different from the
+** related OP_MoveGt, OP_MoveLt, and OP_MoveLe) is that if P2 is
+** zero and P1 is an SQL table (a b-tree with integer keys) then
+** the seek is deferred until it is actually needed.  It might be
+** the case that the cursor is never accessed.  By deferring the
+** seek, we avoid unnecessary seeks.
+**
+** See also: Found, NotFound, Distinct, MoveLt, MoveGt, MoveLe
+*/
+/* Opcode: MoveGt P1 P2 P3 P4 *
+**
+** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
+** use the integer value in register P3 as a key. If cursor P1 refers 
+** to an SQL index, then P3 is the first in an array of P4 registers 
+** that are used as an unpacked index key. 
+**
+** Reposition cursor P1 so that  it points to the smallest entry that 
+** is greater than the key value. If there are no records greater than 
+** the key and P2 is not zero, then jump to P2.
+**
+** See also: Found, NotFound, Distinct, MoveLt, MoveGe, MoveLe
+*/
+/* Opcode: MoveLt P1 P2 P3 P4 * 
+**
+** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
+** use the integer value in register P3 as a key. If cursor P1 refers 
+** to an SQL index, then P3 is the first in an array of P4 registers 
+** that are used as an unpacked index key. 
+**
+** Reposition cursor P1 so that  it points to the largest entry that 
+** is less than the key value. If there are no records less than 
+** the key and P2 is not zero, then jump to P2.
+**
+** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLe
+*/
+/* Opcode: MoveLe P1 P2 P3 P4 *
+**
+** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
+** use the integer value in register P3 as a key. If cursor P1 refers 
+** to an SQL index, then P3 is the first in an array of P4 registers 
+** that are used as an unpacked index key. 
+**
+** Reposition cursor P1 so that it points to the largest entry that 
+** is less than or equal to the key value. If there are no records 
+** less than or equal to the key and P2 is not zero, then jump to P2.
+**
+** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLt
+*/
+case OP_MoveLt:         /* jump, in3 */
+case OP_MoveLe:         /* jump, in3 */
+case OP_MoveGe:         /* jump, in3 */
+case OP_MoveGt: {       /* jump, in3 */
+  int i = pOp->p1;
+  Cursor *pC;
+
+  assert( i>=0 && i<p->nCursor );
+  pC = p->apCsr[i];
+  assert( pC!=0 );
+  if( pC->pCursor!=0 ){
+    int res, oc;
+    oc = pOp->opcode;
+    pC->nullRow = 0;
+    *pC->pIncrKey = oc==OP_MoveGt || oc==OP_MoveLe;
+    if( pC->isTable ){
+      i64 iKey = sqlite3VdbeIntValue(pIn3);
+      if( pOp->p2==0 ){
+        assert( pOp->opcode==OP_MoveGe );
+        pC->movetoTarget = iKey;
+        pC->rowidIsValid = 0;
+        pC->deferredMoveto = 1;
+        break;
+      }
+      rc = sqlite3BtreeMoveto(pC->pCursor, 0, 0, (u64)iKey, 0, &res);
+      if( rc!=SQLITE_OK ){
+        goto abort_due_to_error;
+      }
+      pC->lastRowid = iKey;
+      pC->rowidIsValid = res==0;
+    }else{
+      UnpackedRecord r;
+      int nField = pOp->p4.i;
+      assert( pOp->p4type==P4_INT32 );
+      assert( nField>0 );
+      r.pKeyInfo = pC->pKeyInfo;
+      r.nField = nField;
+      r.needFree = 0;
+      r.needDestroy = 0;
+      r.aMem = &p->aMem[pOp->p3];
+      rc = sqlite3BtreeMoveto(pC->pCursor, 0, &r, 0, 0, &res);
+      if( rc!=SQLITE_OK ){
+        goto abort_due_to_error;
+      }
+      pC->rowidIsValid = 0;
+    }
+    pC->deferredMoveto = 0;
+    pC->cacheStatus = CACHE_STALE;
+    *pC->pIncrKey = 0;
+#ifdef SQLITE_TEST
+    sqlite3_search_count++;
+#endif
+    if( oc==OP_MoveGe || oc==OP_MoveGt ){
+      if( res<0 ){
+        rc = sqlite3BtreeNext(pC->pCursor, &res);
+        if( rc!=SQLITE_OK ) goto abort_due_to_error;
+        pC->rowidIsValid = 0;
+      }else{
+        res = 0;
+      }
+    }else{
+      assert( oc==OP_MoveLt || oc==OP_MoveLe );
+      if( res>=0 ){
+        rc = sqlite3BtreePrevious(pC->pCursor, &res);
+        if( rc!=SQLITE_OK ) goto abort_due_to_error;
+        pC->rowidIsValid = 0;
+      }else{
+        /* res might be negative because the table is empty.  Check to
+        ** see if this is the case.
+        */
+        res = sqlite3BtreeEof(pC->pCursor);
+      }
+    }
+    assert( pOp->p2>0 );
+    if( res ){
+      pc = pOp->p2 - 1;
+    }
+  }else if( !pC->pseudoTable ){
+    /* This happens when attempting to open the sqlite3_master table
+    ** for read access returns SQLITE_EMPTY. In this case always
+    ** take the jump (since there are no records in the table).
+    */
+    pc = pOp->p2 - 1;
+  }
+  break;
+}
+
+/* Opcode: Found P1 P2 P3 * *
+**
+** Register P3 holds a blob constructed by MakeRecord.  P1 is an index.
+** If an entry that matches the value in register p3 exists in P1 then
+** jump to P2.  If the P3 value does not match any entry in P1
+** then fall thru.  The P1 cursor is left pointing at the matching entry
+** if it exists.
+**
+** This instruction is used to implement the IN operator where the
+** left-hand side is a SELECT statement.  P1 may be a true index, or it
+** may be a temporary index that holds the results of the SELECT
+** statement.   This instruction is also used to implement the
+** DISTINCT keyword in SELECT statements.
+**
+** This instruction checks if index P1 contains a record for which 
+** the first N serialized values exactly match the N serialized values
+** in the record in register P3, where N is the total number of values in
+** the P3 record (the P3 record is a prefix of the P1 record). 
+**
+** See also: NotFound, MoveTo, IsUnique, NotExists
+*/
+/* Opcode: NotFound P1 P2 P3 * *
+**
+** Register P3 holds a blob constructed by MakeRecord.  P1 is
+** an index.  If no entry exists in P1 that matches the blob then jump
+** to P2.  If an entry does existing, fall through.  The cursor is left
+** pointing to the entry that matches.
+**
+** See also: Found, MoveTo, NotExists, IsUnique
+*/
+case OP_NotFound:       /* jump, in3 */
+case OP_Found: {        /* jump, in3 */
+  int i = pOp->p1;
+  int alreadyExists = 0;
+  Cursor *pC;
+  assert( i>=0 && i<p->nCursor );
+  assert( p->apCsr[i]!=0 );
+  if( (pC = p->apCsr[i])->pCursor!=0 ){
+    int res;
+    assert( pC->isTable==0 );
+    assert( pIn3->flags & MEM_Blob );
+    if( pOp->opcode==OP_Found ){
+      pC->pKeyInfo->prefixIsEqual = 1;
+    }
+    rc = sqlite3BtreeMoveto(pC->pCursor, pIn3->z, 0, pIn3->n, 0, &res);
+    pC->pKeyInfo->prefixIsEqual = 0;
+    if( rc!=SQLITE_OK ){
+      break;
+    }
+    alreadyExists = (res==0);
+    pC->deferredMoveto = 0;
+    pC->cacheStatus = CACHE_STALE;
+  }
+  if( pOp->opcode==OP_Found ){
+    if( alreadyExists ) pc = pOp->p2 - 1;
+  }else{
+    if( !alreadyExists ) pc = pOp->p2 - 1;
+  }
+  break;
+}
+
+/* Opcode: IsUnique P1 P2 P3 P4 *
+**
+** The P3 register contains an integer record number.  Call this
+** record number R.  The P4 register contains an index key created
+** using MakeIdxRec.  Call it K.
+**
+** P1 is an index.  So it has no data and its key consists of a
+** record generated by OP_MakeRecord where the last field is the 
+** rowid of the entry that the index refers to.
+** 
+** This instruction asks if there is an entry in P1 where the
+** fields matches K but the rowid is different from R.
+** If there is no such entry, then there is an immediate
+** jump to P2.  If any entry does exist where the index string
+** matches K but the record number is not R, then the record
+** number for that entry is written into P3 and control
+** falls through to the next instruction.
+**
+** See also: NotFound, NotExists, Found
+*/
+case OP_IsUnique: {        /* jump, in3 */
+  int i = pOp->p1;
+  Cursor *pCx;
+  BtCursor *pCrsr;
+  Mem *pK;
+  i64 R;
+
+  /* Pop the value R off the top of the stack
+  */
+  assert( pOp->p4type==P4_INT32 );
+  assert( pOp->p4.i>0 && pOp->p4.i<=p->nMem );
+  pK = &p->aMem[pOp->p4.i];
+  sqlite3VdbeMemIntegerify(pIn3);
+  R = pIn3->u.i;
+  assert( i>=0 && i<p->nCursor );
+  pCx = p->apCsr[i];
+  assert( pCx!=0 );
+  pCrsr = pCx->pCursor;
+  if( pCrsr!=0 ){
+    int res;
+    i64 v;         /* The record number on the P1 entry that matches K */
+    char *zKey;    /* The value of K */
+    int nKey;      /* Number of bytes in K */
+    int len;       /* Number of bytes in K without the rowid at the end */
+    int szRowid;   /* Size of the rowid column at the end of zKey */
+
+    /* Make sure K is a string and make zKey point to K
+    */
+    assert( pK->flags & MEM_Blob );
+    zKey = pK->z;
+    nKey = pK->n;
+
+    /* sqlite3VdbeIdxRowidLen() only returns other than SQLITE_OK when the
+    ** record passed as an argument corrupt. Since the record in this case
+    ** has just been created by an OP_MakeRecord instruction, and not loaded
+    ** from the database file, it is not possible for it to be corrupt.
+    ** Therefore, assert(rc==SQLITE_OK).
+    */
+    rc = sqlite3VdbeIdxRowidLen((u8*)zKey, nKey, &szRowid);
+    assert(rc==SQLITE_OK);
+    len = nKey-szRowid;
+
+    /* Search for an entry in P1 where all but the last four bytes match K.
+    ** If there is no such entry, jump immediately to P2.
+    */
+    assert( pCx->deferredMoveto==0 );
+    pCx->cacheStatus = CACHE_STALE;
+    rc = sqlite3BtreeMoveto(pCrsr, zKey, 0, len, 0, &res);
+    if( rc!=SQLITE_OK ){
+      goto abort_due_to_error;
+    }
+    if( res<0 ){
+      rc = sqlite3BtreeNext(pCrsr, &res);
+      if( res ){
+        pc = pOp->p2 - 1;
+        break;
+      }
+    }
+    rc = sqlite3VdbeIdxKeyCompare(pCx, 0, len, (u8*)zKey, &res); 
+    if( rc!=SQLITE_OK ) goto abort_due_to_error;
+    if( res>0 ){
+      pc = pOp->p2 - 1;
+      break;
+    }
+
+    /* At this point, pCrsr is pointing to an entry in P1 where all but
+    ** the final entry (the rowid) matches K.  Check to see if the
+    ** final rowid column is different from R.  If it equals R then jump
+    ** immediately to P2.
+    */
+    rc = sqlite3VdbeIdxRowid(pCrsr, &v);
+    if( rc!=SQLITE_OK ){
+      goto abort_due_to_error;
+    }
+    if( v==R ){
+      pc = pOp->p2 - 1;
+      break;
+    }
+
+    /* The final varint of the key is different from R.  Store it back
+    ** into register R3.  (The record number of an entry that violates
+    ** a UNIQUE constraint.)
+    */
+    pIn3->u.i = v;
+    assert( pIn3->flags&MEM_Int );
+  }
+  break;
+}
+
+/* Opcode: NotExists P1 P2 P3 * *
+**
+** Use the content of register P3 as a integer key.  If a record 
+** with that key does not exist in table of P1, then jump to P2. 
+** If the record does exist, then fall thru.  The cursor is left 
+** pointing to the record if it exists.
+**
+** The difference between this operation and NotFound is that this
+** operation assumes the key is an integer and that P1 is a table whereas
+** NotFound assumes key is a blob constructed from MakeRecord and
+** P1 is an index.
+**
+** See also: Found, MoveTo, NotFound, IsUnique
+*/
+case OP_NotExists: {        /* jump, in3 */
+  int i = pOp->p1;
+  Cursor *pC;
+  BtCursor *pCrsr;
+  assert( i>=0 && i<p->nCursor );
+  assert( p->apCsr[i]!=0 );
+  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
+    int res;
+    u64 iKey;
+    assert( pIn3->flags & MEM_Int );
+    assert( p->apCsr[i]->isTable );
+    iKey = intToKey(pIn3->u.i);
+    rc = sqlite3BtreeMoveto(pCrsr, 0, 0, iKey, 0,&res);
+    pC->lastRowid = pIn3->u.i;
+    pC->rowidIsValid = res==0;
+    pC->nullRow = 0;
+    pC->cacheStatus = CACHE_STALE;
+    /* res might be uninitialized if rc!=SQLITE_OK.  But if rc!=SQLITE_OK
+    ** processing is about to abort so we really do not care whether or not
+    ** the following jump is taken.  (In other words, do not stress over
+    ** the error that valgrind sometimes shows on the next statement when
+    ** running ioerr.test and similar failure-recovery test scripts.) */
+    if( res!=0 ){
+      pc = pOp->p2 - 1;
+      assert( pC->rowidIsValid==0 );
+    }
+  }else if( !pC->pseudoTable ){
+    /* This happens when an attempt to open a read cursor on the 
+    ** sqlite_master table returns SQLITE_EMPTY.
+    */
+    assert( pC->isTable );
+    pc = pOp->p2 - 1;
+    assert( pC->rowidIsValid==0 );
+  }
+  break;
+}
+
+/* Opcode: Sequence P1 P2 * * *
+**
+** Find the next available sequence number for cursor P1.
+** Write the sequence number into register P2.
+** The sequence number on the cursor is incremented after this
+** instruction.  
+*/
+case OP_Sequence: {           /* out2-prerelease */
+  int i = pOp->p1;
+  assert( i>=0 && i<p->nCursor );
+  assert( p->apCsr[i]!=0 );
+  pOut->u.i = p->apCsr[i]->seqCount++;
+  MemSetTypeFlag(pOut, MEM_Int);
+  break;
+}
+
+
+/* Opcode: NewRowid P1 P2 P3 * *
+**
+** Get a new integer record number (a.k.a "rowid") used as the key to a table.
+** The record number is not previously used as a key in the database
+** table that cursor P1 points to.  The new record number is written
+** written to register P2.
+**
+** If P3>0 then P3 is a register that holds the largest previously
+** generated record number.  No new record numbers are allowed to be less
+** than this value.  When this value reaches its maximum, a SQLITE_FULL
+** error is generated.  The P3 register is updated with the generated
+** record number.  This P3 mechanism is used to help implement the
+** AUTOINCREMENT feature.
+*/
+case OP_NewRowid: {           /* out2-prerelease */
+  int i = pOp->p1;
+  i64 v = 0;
+  Cursor *pC;
+  assert( i>=0 && i<p->nCursor );
+  assert( p->apCsr[i]!=0 );
+  if( (pC = p->apCsr[i])->pCursor==0 ){
+    /* The zero initialization above is all that is needed */
+  }else{
+    /* The next rowid or record number (different terms for the same
+    ** thing) is obtained in a two-step algorithm.
+    **
+    ** First we attempt to find the largest existing rowid and add one
+    ** to that.  But if the largest existing rowid is already the maximum
+    ** positive integer, we have to fall through to the second
+    ** probabilistic algorithm
+    **
+    ** The second algorithm is to select a rowid at random and see if
+    ** it already exists in the table.  If it does not exist, we have
+    ** succeeded.  If the random rowid does exist, we select a new one
+    ** and try again, up to 1000 times.
+    **
+    ** For a table with less than 2 billion entries, the probability
+    ** of not finding a unused rowid is about 1.0e-300.  This is a 
+    ** non-zero probability, but it is still vanishingly small and should
+    ** never cause a problem.  You are much, much more likely to have a
+    ** hardware failure than for this algorithm to fail.
+    **
+    ** The analysis in the previous paragraph assumes that you have a good
+    ** source of random numbers.  Is a library function like lrand48()
+    ** good enough?  Maybe. Maybe not. It's hard to know whether there
+    ** might be subtle bugs is some implementations of lrand48() that
+    ** could cause problems. To avoid uncertainty, SQLite uses its own 
+    ** random number generator based on the RC4 algorithm.
+    **
+    ** To promote locality of reference for repetitive inserts, the
+    ** first few attempts at choosing a random rowid pick values just a little
+    ** larger than the previous rowid.  This has been shown experimentally
+    ** to double the speed of the COPY operation.
+    */
+    int res, rx=SQLITE_OK, cnt;
+    i64 x;
+    cnt = 0;
+    if( (sqlite3BtreeFlags(pC->pCursor)&(BTREE_INTKEY|BTREE_ZERODATA)) !=
+          BTREE_INTKEY ){
+      rc = SQLITE_CORRUPT_BKPT;
+      goto abort_due_to_error;
+    }
+    assert( (sqlite3BtreeFlags(pC->pCursor) & BTREE_INTKEY)!=0 );
+    assert( (sqlite3BtreeFlags(pC->pCursor) & BTREE_ZERODATA)==0 );
+
+#ifdef SQLITE_32BIT_ROWID
+#   define MAX_ROWID 0x7fffffff
+#else
+    /* Some compilers complain about constants of the form 0x7fffffffffffffff.
+    ** Others complain about 0x7ffffffffffffffffLL.  The following macro seems
+    ** to provide the constant while making all compilers happy.
+    */
+#   define MAX_ROWID  ( (((u64)0x7fffffff)<<32) | (u64)0xffffffff )
+#endif
+
+    if( !pC->useRandomRowid ){
+      if( pC->nextRowidValid ){
+        v = pC->nextRowid;
+      }else{
+        rc = sqlite3BtreeLast(pC->pCursor, &res);
+        if( rc!=SQLITE_OK ){
+          goto abort_due_to_error;
+        }
+        if( res ){
+          v = 1;
+        }else{
+          sqlite3BtreeKeySize(pC->pCursor, &v);
+          v = keyToInt(v);
+          if( v==MAX_ROWID ){
+            pC->useRandomRowid = 1;
+          }else{
+            v++;
+          }
+        }
+      }
+
+#ifndef SQLITE_OMIT_AUTOINCREMENT
+      if( pOp->p3 ){
+        Mem *pMem;
+        assert( pOp->p3>0 && pOp->p3<=p->nMem ); /* P3 is a valid memory cell */
+        pMem = &p->aMem[pOp->p3];
+	REGISTER_TRACE(pOp->p3, pMem);
+        sqlite3VdbeMemIntegerify(pMem);
+        assert( (pMem->flags & MEM_Int)!=0 );  /* mem(P3) holds an integer */
+        if( pMem->u.i==MAX_ROWID || pC->useRandomRowid ){
+          rc = SQLITE_FULL;
+          goto abort_due_to_error;
+        }
+        if( v<pMem->u.i+1 ){
+          v = pMem->u.i + 1;
+        }
+        pMem->u.i = v;
+      }
+#endif
+
+      if( v<MAX_ROWID ){
+        pC->nextRowidValid = 1;
+        pC->nextRowid = v+1;
+      }else{
+        pC->nextRowidValid = 0;
+      }
+    }
+    if( pC->useRandomRowid ){
+      assert( pOp->p3==0 );  /* SQLITE_FULL must have occurred prior to this */
+      v = db->priorNewRowid;
+      cnt = 0;
+      do{
+        if( cnt==0 && (v&0xffffff)==v ){
+          v++;
+        }else{
+          sqlite3_randomness(sizeof(v), &v);
+          if( cnt<5 ) v &= 0xffffff;
+        }
+        if( v==0 ) continue;
+        x = intToKey(v);
+        rx = sqlite3BtreeMoveto(pC->pCursor, 0, 0, (u64)x, 0, &res);
+        cnt++;
+      }while( cnt<100 && rx==SQLITE_OK && res==0 );
+      db->priorNewRowid = v;
+      if( rx==SQLITE_OK && res==0 ){
+        rc = SQLITE_FULL;
+        goto abort_due_to_error;
+      }
+    }
+    pC->rowidIsValid = 0;
+    pC->deferredMoveto = 0;
+    pC->cacheStatus = CACHE_STALE;
+  }
+  MemSetTypeFlag(pOut, MEM_Int);
+  pOut->u.i = v;
+  break;
+}
+
+/* Opcode: Insert P1 P2 P3 P4 P5
+**
+** Write an entry into the table of cursor P1.  A new entry is
+** created if it doesn't already exist or the data for an existing
+** entry is overwritten.  The data is the value stored register
+** number P2. The key is stored in register P3. The key must
+** be an integer.
+**
+** If the OPFLAG_NCHANGE flag of P5 is set, then the row change count is
+** incremented (otherwise not).  If the OPFLAG_LASTROWID flag of P5 is set,
+** then rowid is stored for subsequent return by the
+** sqlite3_last_insert_rowid() function (otherwise it is unmodified).
+**
+** Parameter P4 may point to a string containing the table-name, or
+** may be NULL. If it is not NULL, then the update-hook 
+** (sqlite3.xUpdateCallback) is invoked following a successful insert.
+**
+** (WARNING/TODO: If P1 is a pseudo-cursor and P2 is dynamically
+** allocated, then ownership of P2 is transferred to the pseudo-cursor
+** and register P2 becomes ephemeral.  If the cursor is changed, the
+** value of register P2 will then change.  Make sure this does not
+** cause any problems.)
+**
+** This instruction only works on tables.  The equivalent instruction
+** for indices is OP_IdxInsert.
+*/
+case OP_Insert: {
+  Mem *pData = &p->aMem[pOp->p2];
+  Mem *pKey = &p->aMem[pOp->p3];
+
+  i64 iKey;   /* The integer ROWID or key for the record to be inserted */
+  int i = pOp->p1;
+  Cursor *pC;
+  assert( i>=0 && i<p->nCursor );
+  pC = p->apCsr[i];
+  assert( pC!=0 );
+  assert( pC->pCursor!=0 || pC->pseudoTable );
+  assert( pKey->flags & MEM_Int );
+  assert( pC->isTable );
+  REGISTER_TRACE(pOp->p2, pData);
+  REGISTER_TRACE(pOp->p3, pKey);
+
+  iKey = intToKey(pKey->u.i);
+  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
+  if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = pKey->u.i;
+  if( pC->nextRowidValid && pKey->u.i>=pC->nextRowid ){
+    pC->nextRowidValid = 0;
+  }
+  if( pData->flags & MEM_Null ){
+    pData->z = 0;
+    pData->n = 0;
+  }else{
+    assert( pData->flags & (MEM_Blob|MEM_Str) );
+  }
+  if( pC->pseudoTable ){
+    if( !pC->ephemPseudoTable ){
+      sqlite3DbFree(db, pC->pData);
+    }
+    pC->iKey = iKey;
+    pC->nData = pData->n;
+    if( pData->z==pData->zMalloc || pC->ephemPseudoTable ){
+      pC->pData = pData->z;
+      if( !pC->ephemPseudoTable ){
+        pData->flags &= ~MEM_Dyn;
+        pData->flags |= MEM_Ephem;
+        pData->zMalloc = 0;
+      }
+    }else{
+      pC->pData = sqlite3Malloc( pC->nData+2 );
+      if( !pC->pData ) goto no_mem;
+      memcpy(pC->pData, pData->z, pC->nData);
+      pC->pData[pC->nData] = 0;
+      pC->pData[pC->nData+1] = 0;
+    }
+    pC->nullRow = 0;
+  }else{
+    int nZero;
+    if( pData->flags & MEM_Zero ){
+      nZero = pData->u.i;
+    }else{
+      nZero = 0;
+    }
+    rc = sqlite3BtreeInsert(pC->pCursor, 0, iKey,
+                            pData->z, pData->n, nZero,
+                            pOp->p5 & OPFLAG_APPEND);
+  }
+  
+  pC->rowidIsValid = 0;
+  pC->deferredMoveto = 0;
+  pC->cacheStatus = CACHE_STALE;
+
+  /* Invoke the update-hook if required. */
+  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
+    const char *zDb = db->aDb[pC->iDb].zName;
+    const char *zTbl = pOp->p4.z;
+    int op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
+    assert( pC->isTable );
+    db->xUpdateCallback(db->pUpdateArg, op, zDb, zTbl, iKey);
+    assert( pC->iDb>=0 );
+  }
+  break;
+}
+
+/* Opcode: Delete P1 P2 * P4 *
+**
+** Delete the record at which the P1 cursor is currently pointing.
+**
+** The cursor will be left pointing at either the next or the previous
+** record in the table. If it is left pointing at the next record, then
+** the next Next instruction will be a no-op.  Hence it is OK to delete
+** a record from within an Next loop.
+**
+** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
+** incremented (otherwise not).
+**
+** P1 must not be pseudo-table.  It has to be a real table with
+** multiple rows.
+**
+** If P4 is not NULL, then it is the name of the table that P1 is
+** pointing to.  The update hook will be invoked, if it exists.
+** If P4 is not NULL then the P1 cursor must have been positioned
+** using OP_NotFound prior to invoking this opcode.
+*/
+case OP_Delete: {
+  int i = pOp->p1;
+  i64 iKey;
+  Cursor *pC;
+
+  assert( i>=0 && i<p->nCursor );
+  pC = p->apCsr[i];
+  assert( pC!=0 );
+  assert( pC->pCursor!=0 );  /* Only valid for real tables, no pseudotables */
+
+  /* If the update-hook will be invoked, set iKey to the rowid of the
+  ** row being deleted.
+  */
+  if( db->xUpdateCallback && pOp->p4.z ){
+    assert( pC->isTable );
+    assert( pC->rowidIsValid );  /* lastRowid set by previous OP_NotFound */
+    iKey = pC->lastRowid;
+  }
+
+  rc = sqlite3VdbeCursorMoveto(pC);
+  if( rc ) goto abort_due_to_error;
+  rc = sqlite3BtreeDelete(pC->pCursor);
+  pC->nextRowidValid = 0;
+  pC->cacheStatus = CACHE_STALE;
+
+  /* Invoke the update-hook if required. */
+  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
+    const char *zDb = db->aDb[pC->iDb].zName;
+    const char *zTbl = pOp->p4.z;
+    db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, zTbl, iKey);
+    assert( pC->iDb>=0 );
+  }
+  if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
+  break;
+}
+
+/* Opcode: ResetCount P1 * *
+**
+** This opcode resets the VMs internal change counter to 0. If P1 is true,
+** then the value of the change counter is copied to the database handle
+** change counter (returned by subsequent calls to sqlite3_changes())
+** before it is reset. This is used by trigger programs.
+*/
+case OP_ResetCount: {
+  if( pOp->p1 ){
+    sqlite3VdbeSetChanges(db, p->nChange);
+  }
+  p->nChange = 0;
+  break;
+}
+
+/* Opcode: RowData P1 P2 * * *
+**
+** Write into register P2 the complete row data for cursor P1.
+** There is no interpretation of the data.  
+** It is just copied onto the P2 register exactly as 
+** it is found in the database file.
+**
+** If the P1 cursor must be pointing to a valid row (not a NULL row)
+** of a real table, not a pseudo-table.
+*/
+/* Opcode: RowKey P1 P2 * * *
+**
+** Write into register P2 the complete row key for cursor P1.
+** There is no interpretation of the data.  
+** The key is copied onto the P3 register exactly as 
+** it is found in the database file.
+**
+** If the P1 cursor must be pointing to a valid row (not a NULL row)
+** of a real table, not a pseudo-table.
+*/
+case OP_RowKey:
+case OP_RowData: {
+  int i = pOp->p1;
+  Cursor *pC;
+  BtCursor *pCrsr;
+  u32 n;
+
+  pOut = &p->aMem[pOp->p2];
+
+  /* Note that RowKey and RowData are really exactly the same instruction */
+  assert( i>=0 && i<p->nCursor );
+  pC = p->apCsr[i];
+  assert( pC->isTable || pOp->opcode==OP_RowKey );
+  assert( pC->isIndex || pOp->opcode==OP_RowData );
+  assert( pC!=0 );
+  assert( pC->nullRow==0 );
+  assert( pC->pseudoTable==0 );
+  assert( pC->pCursor!=0 );
+  pCrsr = pC->pCursor;
+  rc = sqlite3VdbeCursorMoveto(pC);
+  if( rc ) goto abort_due_to_error;
+  if( pC->isIndex ){
+    i64 n64;
+    assert( !pC->isTable );
+    sqlite3BtreeKeySize(pCrsr, &n64);
+    if( n64>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+      goto too_big;
+    }
+    n = n64;
+  }else{
+    sqlite3BtreeDataSize(pCrsr, &n);
+    if( n>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+      goto too_big;
+    }
+  }
+  if( sqlite3VdbeMemGrow(pOut, n, 0) ){
+    goto no_mem;
+  }
+  pOut->n = n;
+  MemSetTypeFlag(pOut, MEM_Blob);
+  if( pC->isIndex ){
+    rc = sqlite3BtreeKey(pCrsr, 0, n, pOut->z);
+  }else{
+    rc = sqlite3BtreeData(pCrsr, 0, n, pOut->z);
+  }
+  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever cast to text */
+  UPDATE_MAX_BLOBSIZE(pOut);
+  break;
+}
+
+/* Opcode: Rowid P1 P2 * * *
+**
+** Store in register P2 an integer which is the key of the table entry that
+** P1 is currently point to.
+*/
+case OP_Rowid: {                 /* out2-prerelease */
+  int i = pOp->p1;
+  Cursor *pC;
+  i64 v;
+
+  assert( i>=0 && i<p->nCursor );
+  pC = p->apCsr[i];
+  assert( pC!=0 );
+  rc = sqlite3VdbeCursorMoveto(pC);
+  if( rc ) goto abort_due_to_error;
+  if( pC->rowidIsValid ){
+    v = pC->lastRowid;
+  }else if( pC->pseudoTable ){
+    v = keyToInt(pC->iKey);
+  }else if( pC->nullRow ){
+    /* Leave the rowid set to a NULL */
+    break;
+  }else{
+    assert( pC->pCursor!=0 );
+    sqlite3BtreeKeySize(pC->pCursor, &v);
+    v = keyToInt(v);
+  }
+  pOut->u.i = v;
+  MemSetTypeFlag(pOut, MEM_Int);
+  break;
+}
+
+/* Opcode: NullRow P1 * * * *
+**
+** Move the cursor P1 to a null row.  Any OP_Column operations
+** that occur while the cursor is on the null row will always
+** write a NULL.
+*/
+case OP_NullRow: {
+  int i = pOp->p1;
+  Cursor *pC;
+
+  assert( i>=0 && i<p->nCursor );
+  pC = p->apCsr[i];
+  assert( pC!=0 );
+  pC->nullRow = 1;
+  pC->rowidIsValid = 0;
+  break;
+}
+
+/* Opcode: Last P1 P2 * * *
+**
+** The next use of the Rowid or Column or Next instruction for P1 
+** will refer to the last entry in the database table or index.
+** If the table or index is empty and P2>0, then jump immediately to P2.
+** If P2 is 0 or if the table or index is not empty, fall through
+** to the following instruction.
+*/
+case OP_Last: {        /* jump */
+  int i = pOp->p1;
+  Cursor *pC;
+  BtCursor *pCrsr;
+  int res;
+
+  assert( i>=0 && i<p->nCursor );
+  pC = p->apCsr[i];
+  assert( pC!=0 );
+  pCrsr = pC->pCursor;
+  assert( pCrsr!=0 );
+  rc = sqlite3BtreeLast(pCrsr, &res);
+  pC->nullRow = res;
+  pC->deferredMoveto = 0;
+  pC->cacheStatus = CACHE_STALE;
+  if( res && pOp->p2>0 ){
+    pc = pOp->p2 - 1;
+  }
+  break;
+}
+
+
+/* Opcode: Sort P1 P2 * * *
+**
+** This opcode does exactly the same thing as OP_Rewind except that
+** it increments an undocumented global variable used for testing.
+**
+** Sorting is accomplished by writing records into a sorting index,
+** then rewinding that index and playing it back from beginning to
+** end.  We use the OP_Sort opcode instead of OP_Rewind to do the
+** rewinding so that the global variable will be incremented and
+** regression tests can determine whether or not the optimizer is
+** correctly optimizing out sorts.
+*/
+case OP_Sort: {        /* jump */
+#ifdef SQLITE_TEST
+  sqlite3_sort_count++;
+  sqlite3_search_count--;
+#endif
+  /* Fall through into OP_Rewind */
+}
+/* Opcode: Rewind P1 P2 * * *
+**
+** The next use of the Rowid or Column or Next instruction for P1 
+** will refer to the first entry in the database table or index.
+** If the table or index is empty and P2>0, then jump immediately to P2.
+** If P2 is 0 or if the table or index is not empty, fall through
+** to the following instruction.
+*/
+case OP_Rewind: {        /* jump */
+  int i = pOp->p1;
+  Cursor *pC;
+  BtCursor *pCrsr;
+  int res;
+
+  assert( i>=0 && i<p->nCursor );
+  pC = p->apCsr[i];
+  assert( pC!=0 );
+  if( (pCrsr = pC->pCursor)!=0 ){
+    rc = sqlite3BtreeFirst(pCrsr, &res);
+    pC->atFirst = res==0;
+    pC->deferredMoveto = 0;
+    pC->cacheStatus = CACHE_STALE;
+  }else{
+    res = 1;
+  }
+  pC->nullRow = res;
+  assert( pOp->p2>0 && pOp->p2<p->nOp );
+  if( res ){
+    pc = pOp->p2 - 1;
+  }
+  break;
+}
+
+/* Opcode: Next P1 P2 * * *
+**
+** Advance cursor P1 so that it points to the next key/data pair in its
+** table or index.  If there are no more key/value pairs then fall through
+** to the following instruction.  But if the cursor advance was successful,
+** jump immediately to P2.
+**
+** The P1 cursor must be for a real table, not a pseudo-table.
+**
+** See also: Prev
+*/
+/* Opcode: Prev P1 P2 * * *
+**
+** Back up cursor P1 so that it points to the previous key/data pair in its
+** table or index.  If there is no previous key/value pairs then fall through
+** to the following instruction.  But if the cursor backup was successful,
+** jump immediately to P2.
+**
+** The P1 cursor must be for a real table, not a pseudo-table.
+*/
+case OP_Prev:          /* jump */
+case OP_Next: {        /* jump */
+  Cursor *pC;
+  BtCursor *pCrsr;
+  int res;
+
+  CHECK_FOR_INTERRUPT;
+  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
+  pC = p->apCsr[pOp->p1];
+  if( pC==0 ){
+    break;  /* See ticket #2273 */
+  }
+  pCrsr = pC->pCursor;
+  assert( pCrsr );
+  res = 1;
+  assert( pC->deferredMoveto==0 );
+  rc = pOp->opcode==OP_Next ? sqlite3BtreeNext(pCrsr, &res) :
+                              sqlite3BtreePrevious(pCrsr, &res);
+  pC->nullRow = res;
+  pC->cacheStatus = CACHE_STALE;
+  if( res==0 ){
+    pc = pOp->p2 - 1;
+#ifdef SQLITE_TEST
+    sqlite3_search_count++;
+#endif
+  }
+  pC->rowidIsValid = 0;
+  break;
+}
+
+/* Opcode: IdxInsert P1 P2 P3 * *
+**
+** Register P2 holds a SQL index key made using the
+** MakeIdxRec instructions.  This opcode writes that key
+** into the index P1.  Data for the entry is nil.
+**
+** P3 is a flag that provides a hint to the b-tree layer that this
+** insert is likely to be an append.
+**
+** This instruction only works for indices.  The equivalent instruction
+** for tables is OP_Insert.
+*/
+case OP_IdxInsert: {        /* in2 */
+  int i = pOp->p1;
+  Cursor *pC;
+  BtCursor *pCrsr;
+  assert( i>=0 && i<p->nCursor );
+  assert( p->apCsr[i]!=0 );
+  assert( pIn2->flags & MEM_Blob );
+  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
+    assert( pC->isTable==0 );
+    rc = ExpandBlob(pIn2);
+    if( rc==SQLITE_OK ){
+      int nKey = pIn2->n;
+      const char *zKey = pIn2->z;
+      rc = sqlite3BtreeInsert(pCrsr, zKey, nKey, "", 0, 0, pOp->p3);
+      assert( pC->deferredMoveto==0 );
+      pC->cacheStatus = CACHE_STALE;
+    }
+  }
+  break;
+}
+
+/* Opcode: IdxDeleteM P1 P2 P3 * *
+**
+** The content of P3 registers starting at register P2 form
+** an unpacked index key. This opcode removes that entry from the 
+** index opened by cursor P1.
+*/
+case OP_IdxDelete: {
+  int i = pOp->p1;
+  Cursor *pC;
+  BtCursor *pCrsr;
+  assert( pOp->p3>0 );
+  assert( pOp->p2>0 && pOp->p2+pOp->p3<=p->nMem );
+  assert( i>=0 && i<p->nCursor );
+  assert( p->apCsr[i]!=0 );
+  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
+    int res;
+    UnpackedRecord r;
+    r.pKeyInfo = pC->pKeyInfo;
+    r.nField = pOp->p3;
+    r.needFree = 0;
+    r.needDestroy = 0;
+    r.aMem = &p->aMem[pOp->p2];
+    rc = sqlite3BtreeMoveto(pCrsr, 0, &r, 0, 0, &res);
+    if( rc==SQLITE_OK && res==0 ){
+      rc = sqlite3BtreeDelete(pCrsr);
+    }
+    assert( pC->deferredMoveto==0 );
+    pC->cacheStatus = CACHE_STALE;
+  }
+  break;
+}
+
+/* Opcode: IdxRowid P1 P2 * * *
+**
+** Write into register P2 an integer which is the last entry in the record at
+** the end of the index key pointed to by cursor P1.  This integer should be
+** the rowid of the table entry to which this index entry points.
+**
+** See also: Rowid, MakeIdxRec.
+*/
+case OP_IdxRowid: {              /* out2-prerelease */
+  int i = pOp->p1;
+  BtCursor *pCrsr;
+  Cursor *pC;
+
+  assert( i>=0 && i<p->nCursor );
+  assert( p->apCsr[i]!=0 );
+  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
+    i64 rowid;
+
+    assert( pC->deferredMoveto==0 );
+    assert( pC->isTable==0 );
+    if( !pC->nullRow ){
+      rc = sqlite3VdbeIdxRowid(pCrsr, &rowid);
+      if( rc!=SQLITE_OK ){
+        goto abort_due_to_error;
+      }
+      MemSetTypeFlag(pOut, MEM_Int);
+      pOut->u.i = rowid;
+    }
+  }
+  break;
+}
+
+/* Opcode: IdxGE P1 P2 P3 P4 P5
+**
+** The P4 register values beginning with P3 form an unpacked index 
+** key that omits the ROWID.  Compare this key value against the index 
+** that P1 is currently pointing to, ignoring the ROWID on the P1 index.
+**
+** If the P1 index entry is greater than or equal to the key value
+** then jump to P2.  Otherwise fall through to the next instruction.
+**
+** If P5 is non-zero then the key value is increased by an epsilon 
+** prior to the comparison.  This make the opcode work like IdxGT except
+** that if the key from register P3 is a prefix of the key in the cursor,
+** the result is false whereas it would be true with IdxGT.
+*/
+/* Opcode: IdxLT P1 P2 P3 * P5
+**
+** The P4 register values beginning with P3 form an unpacked index 
+** key that omits the ROWID.  Compare this key value against the index 
+** that P1 is currently pointing to, ignoring the ROWID on the P1 index.
+**
+** If the P1 index entry is less than the key value then jump to P2.
+** Otherwise fall through to the next instruction.
+**
+** If P5 is non-zero then the key value is increased by an epsilon prior 
+** to the comparison.  This makes the opcode work like IdxLE.
+*/
+case OP_IdxLT:          /* jump, in3 */
+case OP_IdxGE: {        /* jump, in3 */
+  int i= pOp->p1;
+  Cursor *pC;
+
+  assert( i>=0 && i<p->nCursor );
+  assert( p->apCsr[i]!=0 );
+  if( (pC = p->apCsr[i])->pCursor!=0 ){
+    int res;
+    UnpackedRecord r;
+    assert( pC->deferredMoveto==0 );
+    assert( pOp->p5==0 || pOp->p5==1 );
+    assert( pOp->p4type==P4_INT32 );
+    r.pKeyInfo = pC->pKeyInfo;
+    r.nField = pOp->p4.i;
+    r.needFree = 0;
+    r.needDestroy = 0;
+    r.aMem = &p->aMem[pOp->p3];
+    *pC->pIncrKey = pOp->p5;
+    rc = sqlite3VdbeIdxKeyCompare(pC, &r, 0, 0, &res);
+    *pC->pIncrKey = 0;
+    if( pOp->opcode==OP_IdxLT ){
+      res = -res;
+    }else{
+      assert( pOp->opcode==OP_IdxGE );
+      res++;
+    }
+    if( res>0 ){
+      pc = pOp->p2 - 1 ;
+    }
+  }
+  break;
+}
+
+/* Opcode: Destroy P1 P2 P3 * *
+**
+** Delete an entire database table or index whose root page in the database
+** file is given by P1.
+**
+** The table being destroyed is in the main database file if P3==0.  If
+** P3==1 then the table to be clear is in the auxiliary database file
+** that is used to store tables create using CREATE TEMPORARY TABLE.
+**
+** If AUTOVACUUM is enabled then it is possible that another root page
+** might be moved into the newly deleted root page in order to keep all
+** root pages contiguous at the beginning of the database.  The former
+** value of the root page that moved - its value before the move occurred -
+** is stored in register P2.  If no page 
+** movement was required (because the table being dropped was already 
+** the last one in the database) then a zero is stored in register P2.
+** If AUTOVACUUM is disabled then a zero is stored in register P2.
+**
+** See also: Clear
+*/
+case OP_Destroy: {     /* out2-prerelease */
+  int iMoved;
+  int iCnt;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  Vdbe *pVdbe;
+  iCnt = 0;
+  for(pVdbe=db->pVdbe; pVdbe; pVdbe=pVdbe->pNext){
+    if( pVdbe->magic==VDBE_MAGIC_RUN && pVdbe->inVtabMethod<2 && pVdbe->pc>=0 ){
+      iCnt++;
+    }
+  }
+#else
+  iCnt = db->activeVdbeCnt;
+#endif
+  if( iCnt>1 ){
+    rc = SQLITE_LOCKED;
+    p->errorAction = OE_Abort;
+  }else{
+    int iDb = pOp->p3;
+    assert( iCnt==1 );
+    assert( (p->btreeMask & (1<<iDb))!=0 );
+    rc = sqlite3BtreeDropTable(db->aDb[iDb].pBt, pOp->p1, &iMoved);
+    MemSetTypeFlag(pOut, MEM_Int);
+    pOut->u.i = iMoved;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    if( rc==SQLITE_OK && iMoved!=0 ){
+      sqlite3RootPageMoved(&db->aDb[iDb], iMoved, pOp->p1);
+    }
+#endif
+  }
+  break;
+}
+
+/* Opcode: Clear P1 P2 *
+**
+** Delete all contents of the database table or index whose root page
+** in the database file is given by P1.  But, unlike Destroy, do not
+** remove the table or index from the database file.
+**
+** The table being clear is in the main database file if P2==0.  If
+** P2==1 then the table to be clear is in the auxiliary database file
+** that is used to store tables create using CREATE TEMPORARY TABLE.
+**
+** See also: Destroy
+*/
+case OP_Clear: {
+  assert( (p->btreeMask & (1<<pOp->p2))!=0 );
+  rc = sqlite3BtreeClearTable(db->aDb[pOp->p2].pBt, pOp->p1);
+  break;
+}
+
+/* Opcode: CreateTable P1 P2 * * *
+**
+** Allocate a new table in the main database file if P1==0 or in the
+** auxiliary database file if P1==1 or in an attached database if
+** P1>1.  Write the root page number of the new table into
+** register P2
+**
+** The difference between a table and an index is this:  A table must
+** have a 4-byte integer key and can have arbitrary data.  An index
+** has an arbitrary key but no data.
+**
+** See also: CreateIndex
+*/
+/* Opcode: CreateIndex P1 P2 * * *
+**
+** Allocate a new index in the main database file if P1==0 or in the
+** auxiliary database file if P1==1 or in an attached database if
+** P1>1.  Write the root page number of the new table into
+** register P2.
+**
+** See documentation on OP_CreateTable for additional information.
+*/
+case OP_CreateIndex:            /* out2-prerelease */
+case OP_CreateTable: {          /* out2-prerelease */
+  int pgno;
+  int flags;
+  Db *pDb;
+  assert( pOp->p1>=0 && pOp->p1<db->nDb );
+  assert( (p->btreeMask & (1<<pOp->p1))!=0 );
+  pDb = &db->aDb[pOp->p1];
+  assert( pDb->pBt!=0 );
+  if( pOp->opcode==OP_CreateTable ){
+    /* flags = BTREE_INTKEY; */
+    flags = BTREE_LEAFDATA|BTREE_INTKEY;
+  }else{
+    flags = BTREE_ZERODATA;
+  }
+  rc = sqlite3BtreeCreateTable(pDb->pBt, &pgno, flags);
+  if( rc==SQLITE_OK ){
+    pOut->u.i = pgno;
+    MemSetTypeFlag(pOut, MEM_Int);
+  }
+  break;
+}
+
+/* Opcode: ParseSchema P1 P2 * P4 *
+**
+** Read and parse all entries from the SQLITE_MASTER table of database P1
+** that match the WHERE clause P4.  P2 is the "force" flag.   Always do
+** the parsing if P2 is true.  If P2 is false, then this routine is a
+** no-op if the schema is not currently loaded.  In other words, if P2
+** is false, the SQLITE_MASTER table is only parsed if the rest of the
+** schema is already loaded into the symbol table.
+**
+** This opcode invokes the parser to create a new virtual machine,
+** then runs the new virtual machine.  It is thus a re-entrant opcode.
+*/
+case OP_ParseSchema: {
+  char *zSql;
+  int iDb = pOp->p1;
+  const char *zMaster;
+  InitData initData;
+
+  assert( iDb>=0 && iDb<db->nDb );
+  if( !pOp->p2 && !DbHasProperty(db, iDb, DB_SchemaLoaded) ){
+    break;
+  }
+  zMaster = SCHEMA_TABLE(iDb);
+  initData.db = db;
+  initData.iDb = pOp->p1;
+  initData.pzErrMsg = &p->zErrMsg;
+  zSql = sqlite3MPrintf(db,
+     "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s",
+     db->aDb[iDb].zName, zMaster, pOp->p4.z);
+  if( zSql==0 ) goto no_mem;
+  (void)sqlite3SafetyOff(db);
+  assert( db->init.busy==0 );
+  db->init.busy = 1;
+  assert( !db->mallocFailed );
+  rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
+  if( rc==SQLITE_ABORT ) rc = initData.rc;
+  sqlite3DbFree(db, zSql);
+  db->init.busy = 0;
+  (void)sqlite3SafetyOn(db);
+  if( rc==SQLITE_NOMEM ){
+    goto no_mem;
+  }
+  break;  
+}
+
+#if !defined(SQLITE_OMIT_ANALYZE) && !defined(SQLITE_OMIT_PARSER)
+/* Opcode: LoadAnalysis P1 * * * *
+**
+** Read the sqlite_stat1 table for database P1 and load the content
+** of that table into the internal index hash table.  This will cause
+** the analysis to be used when preparing all subsequent queries.
+*/
+case OP_LoadAnalysis: {
+  int iDb = pOp->p1;
+  assert( iDb>=0 && iDb<db->nDb );
+  rc = sqlite3AnalysisLoad(db, iDb);
+  break;  
+}
+#endif /* !defined(SQLITE_OMIT_ANALYZE) && !defined(SQLITE_OMIT_PARSER)  */
+
+/* Opcode: DropTable P1 * * P4 *
+**
+** Remove the internal (in-memory) data structures that describe
+** the table named P4 in database P1.  This is called after a table
+** is dropped in order to keep the internal representation of the
+** schema consistent with what is on disk.
+*/
+case OP_DropTable: {
+  sqlite3UnlinkAndDeleteTable(db, pOp->p1, pOp->p4.z);
+  break;
+}
+
+/* Opcode: DropIndex P1 * * P4 *
+**
+** Remove the internal (in-memory) data structures that describe
+** the index named P4 in database P1.  This is called after an index
+** is dropped in order to keep the internal representation of the
+** schema consistent with what is on disk.
+*/
+case OP_DropIndex: {
+  sqlite3UnlinkAndDeleteIndex(db, pOp->p1, pOp->p4.z);
+  break;
+}
+
+/* Opcode: DropTrigger P1 * * P4 *
+**
+** Remove the internal (in-memory) data structures that describe
+** the trigger named P4 in database P1.  This is called after a trigger
+** is dropped in order to keep the internal representation of the
+** schema consistent with what is on disk.
+*/
+case OP_DropTrigger: {
+  sqlite3UnlinkAndDeleteTrigger(db, pOp->p1, pOp->p4.z);
+  break;
+}
+
+
+#ifndef SQLITE_OMIT_INTEGRITY_CHECK
+/* Opcode: IntegrityCk P1 P2 P3 * P5
+**
+** Do an analysis of the currently open database.  Store in
+** register P1 the text of an error message describing any problems.
+** If no problems are found, store a NULL in register P1.
+**
+** The register P3 contains the maximum number of allowed errors.
+** At most reg(P3) errors will be reported.
+** In other words, the analysis stops as soon as reg(P1) errors are 
+** seen.  Reg(P1) is updated with the number of errors remaining.
+**
+** The root page numbers of all tables in the database are integer
+** stored in reg(P1), reg(P1+1), reg(P1+2), ....  There are P2 tables
+** total.
+**
+** If P5 is not zero, the check is done on the auxiliary database
+** file, not the main database file.
+**
+** This opcode is used to implement the integrity_check pragma.
+*/
+case OP_IntegrityCk: {
+  int nRoot;      /* Number of tables to check.  (Number of root pages.) */
+  int *aRoot;     /* Array of rootpage numbers for tables to be checked */
+  int j;          /* Loop counter */
+  int nErr;       /* Number of errors reported */
+  char *z;        /* Text of the error report */
+  Mem *pnErr;     /* Register keeping track of errors remaining */
+  
+  nRoot = pOp->p2;
+  assert( nRoot>0 );
+  aRoot = sqlite3DbMallocRaw(db, sizeof(int)*(nRoot+1) );
+  if( aRoot==0 ) goto no_mem;
+  assert( pOp->p3>0 && pOp->p3<=p->nMem );
+  pnErr = &p->aMem[pOp->p3];
+  assert( (pnErr->flags & MEM_Int)!=0 );
+  assert( (pnErr->flags & (MEM_Str|MEM_Blob))==0 );
+  pIn1 = &p->aMem[pOp->p1];
+  for(j=0; j<nRoot; j++){
+    aRoot[j] = sqlite3VdbeIntValue(&pIn1[j]);
+  }
+  aRoot[j] = 0;
+  assert( pOp->p5<db->nDb );
+  assert( (p->btreeMask & (1<<pOp->p5))!=0 );
+  z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p5].pBt, aRoot, nRoot,
+                                 pnErr->u.i, &nErr);
+  sqlite3DbFree(db, aRoot);
+  pnErr->u.i -= nErr;
+  sqlite3VdbeMemSetNull(pIn1);
+  if( nErr==0 ){
+    assert( z==0 );
+  }else if( z==0 ){
+    goto no_mem;
+  }else{
+    sqlite3VdbeMemSetStr(pIn1, z, -1, SQLITE_UTF8, sqlite3_free);
+  }
+  UPDATE_MAX_BLOBSIZE(pIn1);
+  sqlite3VdbeChangeEncoding(pIn1, encoding);
+  break;
+}
+#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
+
+/* Opcode: FifoWrite P1 * * * *
+**
+** Write the integer from register P1 into the Fifo.
+*/
+case OP_FifoWrite: {        /* in1 */
+  p->sFifo.db = db;
+  if( sqlite3VdbeFifoPush(&p->sFifo, sqlite3VdbeIntValue(pIn1))==SQLITE_NOMEM ){
+    goto no_mem;
+  }
+  break;
+}
+
+/* Opcode: FifoRead P1 P2 * * *
+**
+** Attempt to read a single integer from the Fifo.  Store that
+** integer in register P1.
+** 
+** If the Fifo is empty jump to P2.
+*/
+case OP_FifoRead: {         /* jump */
+  CHECK_FOR_INTERRUPT;
+  assert( pOp->p1>0 && pOp->p1<=p->nMem );
+  pOut = &p->aMem[pOp->p1];
+  MemSetTypeFlag(pOut, MEM_Int);
+  if( sqlite3VdbeFifoPop(&p->sFifo, &pOut->u.i)==SQLITE_DONE ){
+    pc = pOp->p2 - 1;
+  }
+  break;
+}
+
+#ifndef SQLITE_OMIT_TRIGGER
+/* Opcode: ContextPush * * * 
+**
+** Save the current Vdbe context such that it can be restored by a ContextPop
+** opcode. The context stores the last insert row id, the last statement change
+** count, and the current statement change count.
+*/
+case OP_ContextPush: {
+  int i = p->contextStackTop++;
+  Context *pContext;
+
+  assert( i>=0 );
+  /* FIX ME: This should be allocated as part of the vdbe at compile-time */
+  if( i>=p->contextStackDepth ){
+    p->contextStackDepth = i+1;
+    p->contextStack = sqlite3DbReallocOrFree(db, p->contextStack,
+                                          sizeof(Context)*(i+1));
+    if( p->contextStack==0 ) goto no_mem;
+  }
+  pContext = &p->contextStack[i];
+  pContext->lastRowid = db->lastRowid;
+  pContext->nChange = p->nChange;
+  pContext->sFifo = p->sFifo;
+  sqlite3VdbeFifoInit(&p->sFifo, db);
+  break;
+}
+
+/* Opcode: ContextPop * * * 
+**
+** Restore the Vdbe context to the state it was in when contextPush was last
+** executed. The context stores the last insert row id, the last statement
+** change count, and the current statement change count.
+*/
+case OP_ContextPop: {
+  Context *pContext = &p->contextStack[--p->contextStackTop];
+  assert( p->contextStackTop>=0 );
+  db->lastRowid = pContext->lastRowid;
+  p->nChange = pContext->nChange;
+  sqlite3VdbeFifoClear(&p->sFifo);
+  p->sFifo = pContext->sFifo;
+  break;
+}
+#endif /* #ifndef SQLITE_OMIT_TRIGGER */
+
+#ifndef SQLITE_OMIT_AUTOINCREMENT
+/* Opcode: MemMax P1 P2 * * *
+**
+** Set the value of register P1 to the maximum of its current value
+** and the value in register P2.
+**
+** This instruction throws an error if the memory cell is not initially
+** an integer.
+*/
+case OP_MemMax: {        /* in1, in2 */
+  sqlite3VdbeMemIntegerify(pIn1);
+  sqlite3VdbeMemIntegerify(pIn2);
+  if( pIn1->u.i<pIn2->u.i){
+    pIn1->u.i = pIn2->u.i;
+  }
+  break;
+}
+#endif /* SQLITE_OMIT_AUTOINCREMENT */
+
+/* Opcode: IfPos P1 P2 * * *
+**
+** If the value of register P1 is 1 or greater, jump to P2.
+**
+** It is illegal to use this instruction on a register that does
+** not contain an integer.  An assertion fault will result if you try.
+*/
+case OP_IfPos: {        /* jump, in1 */
+  assert( pIn1->flags&MEM_Int );
+  if( pIn1->u.i>0 ){
+     pc = pOp->p2 - 1;
+  }
+  break;
+}
+
+/* Opcode: IfNeg P1 P2 * * *
+**
+** If the value of register P1 is less than zero, jump to P2. 
+**
+** It is illegal to use this instruction on a register that does
+** not contain an integer.  An assertion fault will result if you try.
+*/
+case OP_IfNeg: {        /* jump, in1 */
+  assert( pIn1->flags&MEM_Int );
+  if( pIn1->u.i<0 ){
+     pc = pOp->p2 - 1;
+  }
+  break;
+}
+
+/* Opcode: IfZero P1 P2 * * *
+**
+** If the value of register P1 is exactly 0, jump to P2. 
+**
+** It is illegal to use this instruction on a register that does
+** not contain an integer.  An assertion fault will result if you try.
+*/
+case OP_IfZero: {        /* jump, in1 */
+  assert( pIn1->flags&MEM_Int );
+  if( pIn1->u.i==0 ){
+     pc = pOp->p2 - 1;
+  }
+  break;
+}
+
+/* Opcode: AggStep * P2 P3 P4 P5
+**
+** Execute the step function for an aggregate.  The
+** function has P5 arguments.   P4 is a pointer to the FuncDef
+** structure that specifies the function.  Use register
+** P3 as the accumulator.
+**
+** The P5 arguments are taken from register P2 and its
+** successors.
+*/
+case OP_AggStep: {
+  int n = pOp->p5;
+  int i;
+  Mem *pMem, *pRec;
+  sqlite3_context ctx;
+  sqlite3_value **apVal;
+
+  assert( n>=0 );
+  pRec = &p->aMem[pOp->p2];
+  apVal = p->apArg;
+  assert( apVal || n==0 );
+  for(i=0; i<n; i++, pRec++){
+    apVal[i] = pRec;
+    storeTypeInfo(pRec, encoding);
+  }
+  ctx.pFunc = pOp->p4.pFunc;
+  assert( pOp->p3>0 && pOp->p3<=p->nMem );
+  ctx.pMem = pMem = &p->aMem[pOp->p3];
+  pMem->n++;
+  ctx.s.flags = MEM_Null;
+  ctx.s.z = 0;
+  ctx.s.zMalloc = 0;
+  ctx.s.xDel = 0;
+  ctx.s.db = db;
+  ctx.isError = 0;
+  ctx.pColl = 0;
+  if( ctx.pFunc->needCollSeq ){
+    assert( pOp>p->aOp );
+    assert( pOp[-1].p4type==P4_COLLSEQ );
+    assert( pOp[-1].opcode==OP_CollSeq );
+    ctx.pColl = pOp[-1].p4.pColl;
+  }
+  (ctx.pFunc->xStep)(&ctx, n, apVal);
+  if( ctx.isError ){
+    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&ctx.s));
+    rc = ctx.isError;
+  }
+  sqlite3VdbeMemRelease(&ctx.s);
+  break;
+}
+
+/* Opcode: AggFinal P1 P2 * P4 *
+**
+** Execute the finalizer function for an aggregate.  P1 is
+** the memory location that is the accumulator for the aggregate.
+**
+** P2 is the number of arguments that the step function takes and
+** P4 is a pointer to the FuncDef for this function.  The P2
+** argument is not used by this opcode.  It is only there to disambiguate
+** functions that can take varying numbers of arguments.  The
+** P4 argument is only needed for the degenerate case where
+** the step function was not previously called.
+*/
+case OP_AggFinal: {
+  Mem *pMem;
+  assert( pOp->p1>0 && pOp->p1<=p->nMem );
+  pMem = &p->aMem[pOp->p1];
+  assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
+  rc = sqlite3VdbeMemFinalize(pMem, pOp->p4.pFunc);
+  if( rc==SQLITE_ERROR ){
+    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(pMem));
+  }
+  sqlite3VdbeChangeEncoding(pMem, encoding);
+  UPDATE_MAX_BLOBSIZE(pMem);
+  if( sqlite3VdbeMemTooBig(pMem) ){
+    goto too_big;
+  }
+  break;
+}
+
+
+#if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
+/* Opcode: Vacuum * * * * *
+**
+** Vacuum the entire database.  This opcode will cause other virtual
+** machines to be created and run.  It may not be called from within
+** a transaction.
+*/
+case OP_Vacuum: {
+  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse; 
+  rc = sqlite3RunVacuum(&p->zErrMsg, db);
+  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+  break;
+}
+#endif
+
+#if !defined(SQLITE_OMIT_AUTOVACUUM)
+/* Opcode: IncrVacuum P1 P2 * * *
+**
+** Perform a single step of the incremental vacuum procedure on
+** the P1 database. If the vacuum has finished, jump to instruction
+** P2. Otherwise, fall through to the next instruction.
+*/
+case OP_IncrVacuum: {        /* jump */
+  Btree *pBt;
+
+  assert( pOp->p1>=0 && pOp->p1<db->nDb );
+  assert( (p->btreeMask & (1<<pOp->p1))!=0 );
+  pBt = db->aDb[pOp->p1].pBt;
+  rc = sqlite3BtreeIncrVacuum(pBt);
+  if( rc==SQLITE_DONE ){
+    pc = pOp->p2 - 1;
+    rc = SQLITE_OK;
+  }
+  break;
+}
+#endif
+
+/* Opcode: Expire P1 * * * *
+**
+** Cause precompiled statements to become expired. An expired statement
+** fails with an error code of SQLITE_SCHEMA if it is ever executed 
+** (via sqlite3_step()).
+** 
+** If P1 is 0, then all SQL statements become expired. If P1 is non-zero,
+** then only the currently executing statement is affected. 
+*/
+case OP_Expire: {
+  if( !pOp->p1 ){
+    sqlite3ExpirePreparedStatements(db);
+  }else{
+    p->expired = 1;
+  }
+  break;
+}
+
+#ifndef SQLITE_OMIT_SHARED_CACHE
+/* Opcode: TableLock P1 P2 P3 P4 *
+**
+** Obtain a lock on a particular table. This instruction is only used when
+** the shared-cache feature is enabled. 
+**
+** If P1 is  the index of the database in sqlite3.aDb[] of the database
+** on which the lock is acquired.  A readlock is obtained if P3==0 or
+** a write lock if P3==1.
+**
+** P2 contains the root-page of the table to lock.
+**
+** P4 contains a pointer to the name of the table being locked. This is only
+** used to generate an error message if the lock cannot be obtained.
+*/
+case OP_TableLock: {
+  int p1 = pOp->p1; 
+  u8 isWriteLock = pOp->p3;
+  assert( p1>=0 && p1<db->nDb );
+  assert( (p->btreeMask & (1<<p1))!=0 );
+  assert( isWriteLock==0 || isWriteLock==1 );
+  rc = sqlite3BtreeLockTable(db->aDb[p1].pBt, pOp->p2, isWriteLock);
+  if( rc==SQLITE_LOCKED ){
+    const char *z = pOp->p4.z;
+    sqlite3SetString(&p->zErrMsg, db, "database table is locked: %s", z);
+  }
+  break;
+}
+#endif /* SQLITE_OMIT_SHARED_CACHE */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VBegin * * * P4 *
+**
+** P4 may be a pointer to an sqlite3_vtab structure. If so, call the 
+** xBegin method for that table.
+**
+** Also, whether or not P4 is set, check that this is not being called from
+** within a callback to a virtual table xSync() method. If it is, set the
+** error code to SQLITE_LOCKED.
+*/
+case OP_VBegin: {
+  sqlite3_vtab *pVtab = pOp->p4.pVtab;
+  rc = sqlite3VtabBegin(db, pVtab);
+  if( pVtab ){
+    sqlite3DbFree(db, p->zErrMsg);
+    p->zErrMsg = pVtab->zErrMsg;
+    pVtab->zErrMsg = 0;
+  }
+  break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VCreate P1 * * P4 *
+**
+** P4 is the name of a virtual table in database P1. Call the xCreate method
+** for that table.
+*/
+case OP_VCreate: {
+  rc = sqlite3VtabCallCreate(db, pOp->p1, pOp->p4.z, &p->zErrMsg);
+  break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VDestroy P1 * * P4 *
+**
+** P4 is the name of a virtual table in database P1.  Call the xDestroy method
+** of that table.
+*/
+case OP_VDestroy: {
+  p->inVtabMethod = 2;
+  rc = sqlite3VtabCallDestroy(db, pOp->p1, pOp->p4.z);
+  p->inVtabMethod = 0;
+  break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VOpen P1 * * P4 *
+**
+** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
+** P1 is a cursor number.  This opcode opens a cursor to the virtual
+** table and stores that cursor in P1.
+*/
+case OP_VOpen: {
+  Cursor *pCur = 0;
+  sqlite3_vtab_cursor *pVtabCursor = 0;
+
+  sqlite3_vtab *pVtab = pOp->p4.pVtab;
+  sqlite3_module *pModule = (sqlite3_module *)pVtab->pModule;
+
+  assert(pVtab && pModule);
+  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+  rc = pModule->xOpen(pVtab, &pVtabCursor);
+  sqlite3DbFree(db, p->zErrMsg);
+  p->zErrMsg = pVtab->zErrMsg;
+  pVtab->zErrMsg = 0;
+  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+  if( SQLITE_OK==rc ){
+    /* Initialize sqlite3_vtab_cursor base class */
+    pVtabCursor->pVtab = pVtab;
+
+    /* Initialise vdbe cursor object */
+    pCur = allocateCursor(p, pOp->p1, &pOp[-1], -1, 0);
+    if( pCur ){
+      pCur->pVtabCursor = pVtabCursor;
+      pCur->pModule = pVtabCursor->pVtab->pModule;
+    }else{
+      db->mallocFailed = 1;
+      pModule->xClose(pVtabCursor);
+    }
+  }
+  break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VFilter P1 P2 P3 P4 *
+**
+** P1 is a cursor opened using VOpen.  P2 is an address to jump to if
+** the filtered result set is empty.
+**
+** P4 is either NULL or a string that was generated by the xBestIndex
+** method of the module.  The interpretation of the P4 string is left
+** to the module implementation.
+**
+** This opcode invokes the xFilter method on the virtual table specified
+** by P1.  The integer query plan parameter to xFilter is stored in register
+** P3. Register P3+1 stores the argc parameter to be passed to the
+** xFilter method. Registers P3+2..P3+1+argc are the argc
+** additional parameters which are passed to
+** xFilter as argv. Register P3+2 becomes argv[0] when passed to xFilter.
+**
+** A jump is made to P2 if the result set after filtering would be empty.
+*/
+case OP_VFilter: {   /* jump */
+  int nArg;
+  int iQuery;
+  const sqlite3_module *pModule;
+  Mem *pQuery = &p->aMem[pOp->p3];
+  Mem *pArgc = &pQuery[1];
+  sqlite3_vtab_cursor *pVtabCursor;
+  sqlite3_vtab *pVtab;
+
+  Cursor *pCur = p->apCsr[pOp->p1];
+
+  REGISTER_TRACE(pOp->p3, pQuery);
+  assert( pCur->pVtabCursor );
+  pVtabCursor = pCur->pVtabCursor;
+  pVtab = pVtabCursor->pVtab;
+  pModule = pVtab->pModule;
+
+  /* Grab the index number and argc parameters */
+  assert( (pQuery->flags&MEM_Int)!=0 && pArgc->flags==MEM_Int );
+  nArg = pArgc->u.i;
+  iQuery = pQuery->u.i;
+
+  /* Invoke the xFilter method */
+  {
+    int res = 0;
+    int i;
+    Mem **apArg = p->apArg;
+    for(i = 0; i<nArg; i++){
+      apArg[i] = &pArgc[i+1];
+      storeTypeInfo(apArg[i], 0);
+    }
+
+    if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+    sqlite3VtabLock(pVtab);
+    p->inVtabMethod = 1;
+    rc = pModule->xFilter(pVtabCursor, iQuery, pOp->p4.z, nArg, apArg);
+    p->inVtabMethod = 0;
+    sqlite3DbFree(db, p->zErrMsg);
+    p->zErrMsg = pVtab->zErrMsg;
+    pVtab->zErrMsg = 0;
+    sqlite3VtabUnlock(db, pVtab);
+    if( rc==SQLITE_OK ){
+      res = pModule->xEof(pVtabCursor);
+    }
+    if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+
+    if( res ){
+      pc = pOp->p2 - 1;
+    }
+  }
+  pCur->nullRow = 0;
+
+  break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VRowid P1 P2 * * *
+**
+** Store into register P2  the rowid of
+** the virtual-table that the P1 cursor is pointing to.
+*/
+case OP_VRowid: {             /* out2-prerelease */
+  sqlite3_vtab *pVtab;
+  const sqlite3_module *pModule;
+  sqlite_int64 iRow;
+  Cursor *pCur = p->apCsr[pOp->p1];
+
+  assert( pCur->pVtabCursor );
+  if( pCur->nullRow ){
+    break;
+  }
+  pVtab = pCur->pVtabCursor->pVtab;
+  pModule = pVtab->pModule;
+  assert( pModule->xRowid );
+  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+  rc = pModule->xRowid(pCur->pVtabCursor, &iRow);
+  sqlite3DbFree(db, p->zErrMsg);
+  p->zErrMsg = pVtab->zErrMsg;
+  pVtab->zErrMsg = 0;
+  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+  MemSetTypeFlag(pOut, MEM_Int);
+  pOut->u.i = iRow;
+  break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VColumn P1 P2 P3 * *
+**
+** Store the value of the P2-th column of
+** the row of the virtual-table that the 
+** P1 cursor is pointing to into register P3.
+*/
+case OP_VColumn: {
+  sqlite3_vtab *pVtab;
+  const sqlite3_module *pModule;
+  Mem *pDest;
+  sqlite3_context sContext;
+
+  Cursor *pCur = p->apCsr[pOp->p1];
+  assert( pCur->pVtabCursor );
+  assert( pOp->p3>0 && pOp->p3<=p->nMem );
+  pDest = &p->aMem[pOp->p3];
+  if( pCur->nullRow ){
+    sqlite3VdbeMemSetNull(pDest);
+    break;
+  }
+  pVtab = pCur->pVtabCursor->pVtab;
+  pModule = pVtab->pModule;
+  assert( pModule->xColumn );
+  memset(&sContext, 0, sizeof(sContext));
+
+  /* The output cell may already have a buffer allocated. Move
+  ** the current contents to sContext.s so in case the user-function 
+  ** can use the already allocated buffer instead of allocating a 
+  ** new one.
+  */
+  sqlite3VdbeMemMove(&sContext.s, pDest);
+  MemSetTypeFlag(&sContext.s, MEM_Null);
+
+  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+  rc = pModule->xColumn(pCur->pVtabCursor, &sContext, pOp->p2);
+  sqlite3DbFree(db, p->zErrMsg);
+  p->zErrMsg = pVtab->zErrMsg;
+  pVtab->zErrMsg = 0;
+
+  /* Copy the result of the function to the P3 register. We
+  ** do this regardless of whether or not an error occured to ensure any
+  ** dynamic allocation in sContext.s (a Mem struct) is  released.
+  */
+  sqlite3VdbeChangeEncoding(&sContext.s, encoding);
+  REGISTER_TRACE(pOp->p3, pDest);
+  sqlite3VdbeMemMove(pDest, &sContext.s);
+  UPDATE_MAX_BLOBSIZE(pDest);
+
+  if( sqlite3SafetyOn(db) ){
+    goto abort_due_to_misuse;
+  }
+  if( sqlite3VdbeMemTooBig(pDest) ){
+    goto too_big;
+  }
+  break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VNext P1 P2 * * *
+**
+** Advance virtual table P1 to the next row in its result set and
+** jump to instruction P2.  Or, if the virtual table has reached
+** the end of its result set, then fall through to the next instruction.
+*/
+case OP_VNext: {   /* jump */
+  sqlite3_vtab *pVtab;
+  const sqlite3_module *pModule;
+  int res = 0;
+
+  Cursor *pCur = p->apCsr[pOp->p1];
+  assert( pCur->pVtabCursor );
+  if( pCur->nullRow ){
+    break;
+  }
+  pVtab = pCur->pVtabCursor->pVtab;
+  pModule = pVtab->pModule;
+  assert( pModule->xNext );
+
+  /* Invoke the xNext() method of the module. There is no way for the
+  ** underlying implementation to return an error if one occurs during
+  ** xNext(). Instead, if an error occurs, true is returned (indicating that 
+  ** data is available) and the error code returned when xColumn or
+  ** some other method is next invoked on the save virtual table cursor.
+  */
+  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+  sqlite3VtabLock(pVtab);
+  p->inVtabMethod = 1;
+  rc = pModule->xNext(pCur->pVtabCursor);
+  p->inVtabMethod = 0;
+  sqlite3DbFree(db, p->zErrMsg);
+  p->zErrMsg = pVtab->zErrMsg;
+  pVtab->zErrMsg = 0;
+  sqlite3VtabUnlock(db, pVtab);
+  if( rc==SQLITE_OK ){
+    res = pModule->xEof(pCur->pVtabCursor);
+  }
+  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+
+  if( !res ){
+    /* If there is data, jump to P2 */
+    pc = pOp->p2 - 1;
+  }
+  break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VRename P1 * * P4 *
+**
+** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
+** This opcode invokes the corresponding xRename method. The value
+** in register P1 is passed as the zName argument to the xRename method.
+*/
+case OP_VRename: {
+  sqlite3_vtab *pVtab = pOp->p4.pVtab;
+  Mem *pName = &p->aMem[pOp->p1];
+  assert( pVtab->pModule->xRename );
+  REGISTER_TRACE(pOp->p1, pName);
+
+  Stringify(pName, encoding);
+
+  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+  sqlite3VtabLock(pVtab);
+  rc = pVtab->pModule->xRename(pVtab, pName->z);
+  sqlite3DbFree(db, p->zErrMsg);
+  p->zErrMsg = pVtab->zErrMsg;
+  pVtab->zErrMsg = 0;
+  sqlite3VtabUnlock(db, pVtab);
+  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+
+  break;
+}
+#endif
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VUpdate P1 P2 P3 P4 *
+**
+** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
+** This opcode invokes the corresponding xUpdate method. P2 values
+** are contiguous memory cells starting at P3 to pass to the xUpdate 
+** invocation. The value in register (P3+P2-1) corresponds to the 
+** p2th element of the argv array passed to xUpdate.
+**
+** The xUpdate method will do a DELETE or an INSERT or both.
+** The argv[0] element (which corresponds to memory cell P3)
+** is the rowid of a row to delete.  If argv[0] is NULL then no 
+** deletion occurs.  The argv[1] element is the rowid of the new 
+** row.  This can be NULL to have the virtual table select the new 
+** rowid for itself.  The subsequent elements in the array are 
+** the values of columns in the new row.
+**
+** If P2==1 then no insert is performed.  argv[0] is the rowid of
+** a row to delete.
+**
+** P1 is a boolean flag. If it is set to true and the xUpdate call
+** is successful, then the value returned by sqlite3_last_insert_rowid() 
+** is set to the value of the rowid for the row just inserted.
+*/
+case OP_VUpdate: {
+  sqlite3_vtab *pVtab = pOp->p4.pVtab;
+  sqlite3_module *pModule = (sqlite3_module *)pVtab->pModule;
+  int nArg = pOp->p2;
+  assert( pOp->p4type==P4_VTAB );
+  if( pModule->xUpdate==0 ){
+    sqlite3SetString(&p->zErrMsg, db, "read-only table");
+    rc = SQLITE_ERROR;
+  }else{
+    int i;
+    sqlite_int64 rowid;
+    Mem **apArg = p->apArg;
+    Mem *pX = &p->aMem[pOp->p3];
+    for(i=0; i<nArg; i++){
+      storeTypeInfo(pX, 0);
+      apArg[i] = pX;
+      pX++;
+    }
+    if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+    sqlite3VtabLock(pVtab);
+    rc = pModule->xUpdate(pVtab, nArg, apArg, &rowid);
+    sqlite3DbFree(db, p->zErrMsg);
+    p->zErrMsg = pVtab->zErrMsg;
+    pVtab->zErrMsg = 0;
+    sqlite3VtabUnlock(db, pVtab);
+    if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+    if( pOp->p1 && rc==SQLITE_OK ){
+      assert( nArg>1 && apArg[0] && (apArg[0]->flags&MEM_Null) );
+      db->lastRowid = rowid;
+    }
+    p->nChange++;
+  }
+  break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifndef  SQLITE_OMIT_PAGER_PRAGMAS
+/* Opcode: Pagecount P1 P2 * * *
+**
+** Write the current number of pages in database P1 to memory cell P2.
+*/
+case OP_Pagecount: {            /* out2-prerelease */
+  int p1 = pOp->p1; 
+  int nPage;
+  Pager *pPager = sqlite3BtreePager(db->aDb[p1].pBt);
+
+  rc = sqlite3PagerPagecount(pPager, &nPage);
+  if( rc==SQLITE_OK ){
+    pOut->flags = MEM_Int;
+    pOut->u.i = nPage;
+  }
+  break;
+}
+#endif
+
+#ifndef SQLITE_OMIT_TRACE
+/* Opcode: Trace * * * P4 *
+**
+** If tracing is enabled (by the sqlite3_trace()) interface, then
+** the UTF-8 string contained in P4 is emitted on the trace callback.
+*/
+case OP_Trace: {
+  if( pOp->p4.z ){
+    if( db->xTrace ){
+      db->xTrace(db->pTraceArg, pOp->p4.z);
+    }
+#ifdef SQLITE_DEBUG
+    if( (db->flags & SQLITE_SqlTrace)!=0 ){
+      sqlite3DebugPrintf("SQL-trace: %s\n", pOp->p4.z);
+    }
+#endif /* SQLITE_DEBUG */
+  }
+  break;
+}
+#endif
+
+
+/* Opcode: Noop * * * * *
+**
+** Do nothing.  This instruction is often useful as a jump
+** destination.
+*/
+/*
+** The magic Explain opcode are only inserted when explain==2 (which
+** is to say when the EXPLAIN QUERY PLAN syntax is used.)
+** This opcode records information from the optimizer.  It is the
+** the same as a no-op.  This opcodesnever appears in a real VM program.
+*/
+default: {          /* This is really OP_Noop and OP_Explain */
+  break;
+}
+
+/*****************************************************************************
+** The cases of the switch statement above this line should all be indented
+** by 6 spaces.  But the left-most 6 spaces have been removed to improve the
+** readability.  From this point on down, the normal indentation rules are
+** restored.
+*****************************************************************************/
+    }
+
+#ifdef VDBE_PROFILE
+    {
+      u64 elapsed = sqlite3Hwtime() - start;
+      pOp->cycles += elapsed;
+      pOp->cnt++;
+#if 0
+        fprintf(stdout, "%10llu ", elapsed);
+        sqlite3VdbePrintOp(stdout, origPc, &p->aOp[origPc]);
+#endif
+    }
+#endif
+
+    /* The following code adds nothing to the actual functionality
+    ** of the program.  It is only here for testing and debugging.
+    ** On the other hand, it does burn CPU cycles every time through
+    ** the evaluator loop.  So we can leave it out when NDEBUG is defined.
+    */
+#ifndef NDEBUG
+    assert( pc>=-1 && pc<p->nOp );
+
+#ifdef SQLITE_DEBUG
+    if( p->trace ){
+      if( rc!=0 ) fprintf(p->trace,"rc=%d\n",rc);
+      if( opProperty & OPFLG_OUT2_PRERELEASE ){
+        registerTrace(p->trace, pOp->p2, pOut);
+      }
+      if( opProperty & OPFLG_OUT3 ){
+        registerTrace(p->trace, pOp->p3, pOut);
+      }
+    }
+#endif  /* SQLITE_DEBUG */
+#endif  /* NDEBUG */
+  }  /* The end of the for(;;) loop the loops through opcodes */
+
+  /* If we reach this point, it means that execution is finished with
+  ** an error of some kind.
+  */
+vdbe_error_halt:
+  assert( rc );
+  p->rc = rc;
+  sqlite3VdbeHalt(p);
+  if( rc==SQLITE_IOERR_NOMEM ) db->mallocFailed = 1;
+  rc = SQLITE_ERROR;
+
+  /* This is the only way out of this procedure.  We have to
+  ** release the mutexes on btrees that were acquired at the
+  ** top. */
+vdbe_return:
+  sqlite3BtreeMutexArrayLeave(&p->aMutex);
+  return rc;
+
+  /* Jump to here if a string or blob larger than SQLITE_MAX_LENGTH
+  ** is encountered.
+  */
+too_big:
+  sqlite3SetString(&p->zErrMsg, db, "string or blob too big");
+  rc = SQLITE_TOOBIG;
+  goto vdbe_error_halt;
+
+  /* Jump to here if a malloc() fails.
+  */
+no_mem:
+  db->mallocFailed = 1;
+  sqlite3SetString(&p->zErrMsg, db, "out of memory");
+  rc = SQLITE_NOMEM;
+  goto vdbe_error_halt;
+
+  /* Jump to here for an SQLITE_MISUSE error.
+  */
+abort_due_to_misuse:
+  rc = SQLITE_MISUSE;
+  /* Fall thru into abort_due_to_error */
+
+  /* Jump to here for any other kind of fatal error.  The "rc" variable
+  ** should hold the error number.
+  */
+abort_due_to_error:
+  assert( p->zErrMsg==0 );
+  if( db->mallocFailed ) rc = SQLITE_NOMEM;
+  if( rc!=SQLITE_IOERR_NOMEM ){
+    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3ErrStr(rc));
+  }
+  goto vdbe_error_halt;
+
+  /* Jump to here if the sqlite3_interrupt() API sets the interrupt
+  ** flag.
+  */
+abort_due_to_interrupt:
+  assert( db->u1.isInterrupted );
+  rc = SQLITE_INTERRUPT;
+  p->rc = rc;
+  sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3ErrStr(rc));
+  goto vdbe_error_halt;
+}
diff --git a/third_party/sqlite/src/vdbe.h b/third_party/sqlite/src/vdbe.h
new file mode 100755
index 0000000..815b615
--- /dev/null
+++ b/third_party/sqlite/src/vdbe.h
@@ -0,0 +1,206 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Header file for the Virtual DataBase Engine (VDBE)
+**
+** This header defines the interface to the virtual database engine
+** or VDBE.  The VDBE implements an abstract machine that runs a
+** simple program to access and modify the underlying database.
+**
+** $Id: vdbe.h,v 1.135 2008/08/01 20:10:08 drh Exp $
+*/
+#ifndef _SQLITE_VDBE_H_
+#define _SQLITE_VDBE_H_
+#include <stdio.h>
+
+/*
+** A single VDBE is an opaque structure named "Vdbe".  Only routines
+** in the source file sqliteVdbe.c are allowed to see the insides
+** of this structure.
+*/
+typedef struct Vdbe Vdbe;
+
+/*
+** The names of the following types declared in vdbeInt.h are required
+** for the VdbeOp definition.
+*/
+typedef struct VdbeFunc VdbeFunc;
+typedef struct Mem Mem;
+typedef struct UnpackedRecord UnpackedRecord;
+
+/*
+** A single instruction of the virtual machine has an opcode
+** and as many as three operands.  The instruction is recorded
+** as an instance of the following structure:
+*/
+struct VdbeOp {
+  u8 opcode;          /* What operation to perform */
+  signed char p4type; /* One of the P4_xxx constants for p4 */
+  u8 opflags;         /* Not currently used */
+  u8 p5;              /* Fifth parameter is an unsigned character */
+  int p1;             /* First operand */
+  int p2;             /* Second parameter (often the jump destination) */
+  int p3;             /* The third parameter */
+  union {             /* forth parameter */
+    int i;                 /* Integer value if p4type==P4_INT32 */
+    void *p;               /* Generic pointer */
+    char *z;               /* Pointer to data for string (char array) types */
+    i64 *pI64;             /* Used when p4type is P4_INT64 */
+    double *pReal;         /* Used when p4type is P4_REAL */
+    FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */
+    VdbeFunc *pVdbeFunc;   /* Used when p4type is P4_VDBEFUNC */
+    CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
+    Mem *pMem;             /* Used when p4type is P4_MEM */
+    sqlite3_vtab *pVtab;   /* Used when p4type is P4_VTAB */
+    KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
+    int *ai;               /* Used when p4type is P4_INTARRAY */
+  } p4;
+#ifdef SQLITE_DEBUG
+  char *zComment;          /* Comment to improve readability */
+#endif
+#ifdef VDBE_PROFILE
+  int cnt;                 /* Number of times this instruction was executed */
+  u64 cycles;              /* Total time spent executing this instruction */
+#endif
+};
+typedef struct VdbeOp VdbeOp;
+
+/*
+** A smaller version of VdbeOp used for the VdbeAddOpList() function because
+** it takes up less space.
+*/
+struct VdbeOpList {
+  u8 opcode;          /* What operation to perform */
+  signed char p1;     /* First operand */
+  signed char p2;     /* Second parameter (often the jump destination) */
+  signed char p3;     /* Third parameter */
+};
+typedef struct VdbeOpList VdbeOpList;
+
+/*
+** Allowed values of VdbeOp.p3type
+*/
+#define P4_NOTUSED    0   /* The P4 parameter is not used */
+#define P4_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */
+#define P4_STATIC   (-2)  /* Pointer to a static string */
+#define P4_COLLSEQ  (-4)  /* P4 is a pointer to a CollSeq structure */
+#define P4_FUNCDEF  (-5)  /* P4 is a pointer to a FuncDef structure */
+#define P4_KEYINFO  (-6)  /* P4 is a pointer to a KeyInfo structure */
+#define P4_VDBEFUNC (-7)  /* P4 is a pointer to a VdbeFunc structure */
+#define P4_MEM      (-8)  /* P4 is a pointer to a Mem*    structure */
+#define P4_TRANSIENT (-9) /* P4 is a pointer to a transient string */
+#define P4_VTAB     (-10) /* P4 is a pointer to an sqlite3_vtab structure */
+#define P4_MPRINTF  (-11) /* P4 is a string obtained from sqlite3_mprintf() */
+#define P4_REAL     (-12) /* P4 is a 64-bit floating point value */
+#define P4_INT64    (-13) /* P4 is a 64-bit signed integer */
+#define P4_INT32    (-14) /* P4 is a 32-bit signed integer */
+#define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */
+
+/* When adding a P4 argument using P4_KEYINFO, a copy of the KeyInfo structure
+** is made.  That copy is freed when the Vdbe is finalized.  But if the
+** argument is P4_KEYINFO_HANDOFF, the passed in pointer is used.  It still
+** gets freed when the Vdbe is finalized so it still should be obtained
+** from a single sqliteMalloc().  But no copy is made and the calling
+** function should *not* try to free the KeyInfo.
+*/
+#define P4_KEYINFO_HANDOFF (-16)
+#define P4_KEYINFO_STATIC  (-17)
+
+/*
+** The Vdbe.aColName array contains 5n Mem structures, where n is the 
+** number of columns of data returned by the statement.
+*/
+#define COLNAME_NAME     0
+#define COLNAME_DECLTYPE 1
+#define COLNAME_DATABASE 2
+#define COLNAME_TABLE    3
+#define COLNAME_COLUMN   4
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+# define COLNAME_N        5      /* Number of COLNAME_xxx symbols */
+#else
+# ifdef SQLITE_OMIT_DECLTYPE
+#   define COLNAME_N      1      /* Store only the name */
+# else
+#   define COLNAME_N      2      /* Store the name and decltype */
+# endif
+#endif
+
+/*
+** The following macro converts a relative address in the p2 field
+** of a VdbeOp structure into a negative number so that 
+** sqlite3VdbeAddOpList() knows that the address is relative.  Calling
+** the macro again restores the address.
+*/
+#define ADDR(X)  (-1-(X))
+
+/*
+** The makefile scans the vdbe.c source file and creates the "opcodes.h"
+** header file that defines a number for each opcode used by the VDBE.
+*/
+#include "opcodes.h"
+
+/*
+** Prototypes for the VDBE interface.  See comments on the implementation
+** for a description of what each of these routines does.
+*/
+Vdbe *sqlite3VdbeCreate(sqlite3*);
+int sqlite3VdbeAddOp0(Vdbe*,int);
+int sqlite3VdbeAddOp1(Vdbe*,int,int);
+int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
+int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
+int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
+int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);
+void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);
+void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);
+void sqlite3VdbeChangeP3(Vdbe*, int addr, int P3);
+void sqlite3VdbeChangeP5(Vdbe*, u8 P5);
+void sqlite3VdbeJumpHere(Vdbe*, int addr);
+void sqlite3VdbeChangeToNoop(Vdbe*, int addr, int N);
+void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
+void sqlite3VdbeUsesBtree(Vdbe*, int);
+VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
+int sqlite3VdbeMakeLabel(Vdbe*);
+void sqlite3VdbeDelete(Vdbe*);
+void sqlite3VdbeMakeReady(Vdbe*,int,int,int,int);
+int sqlite3VdbeFinalize(Vdbe*);
+void sqlite3VdbeResolveLabel(Vdbe*, int);
+int sqlite3VdbeCurrentAddr(Vdbe*);
+#ifdef SQLITE_DEBUG
+  void sqlite3VdbeTrace(Vdbe*,FILE*);
+#endif
+void sqlite3VdbeResetStepResult(Vdbe*);
+int sqlite3VdbeReset(Vdbe*);
+void sqlite3VdbeSetNumCols(Vdbe*,int);
+int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, int);
+void sqlite3VdbeCountChanges(Vdbe*);
+sqlite3 *sqlite3VdbeDb(Vdbe*);
+void sqlite3VdbeSetSql(Vdbe*, const char *z, int n);
+void sqlite3VdbeSwap(Vdbe*,Vdbe*);
+
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+int sqlite3VdbeReleaseMemory(int);
+#endif
+UnpackedRecord *sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,void*,int);
+void sqlite3VdbeDeleteUnpackedRecord(UnpackedRecord*);
+int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
+
+
+#ifndef NDEBUG
+  void sqlite3VdbeComment(Vdbe*, const char*, ...);
+# define VdbeComment(X)  sqlite3VdbeComment X
+  void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
+# define VdbeNoopComment(X)  sqlite3VdbeNoopComment X
+#else
+# define VdbeComment(X)
+# define VdbeNoopComment(X)
+#endif
+
+#endif
diff --git a/third_party/sqlite/src/vdbeInt.h b/third_party/sqlite/src/vdbeInt.h
new file mode 100755
index 0000000..6516f13
--- /dev/null
+++ b/third_party/sqlite/src/vdbeInt.h
@@ -0,0 +1,447 @@
+/*
+** 2003 September 6
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This is the header file for information that is private to the
+** VDBE.  This information used to all be at the top of the single
+** source code file "vdbe.c".  When that file became too big (over
+** 6000 lines long) it was split up into several smaller files and
+** this header information was factored out.
+**
+** $Id: vdbeInt.h,v 1.153 2008/08/02 03:50:39 drh Exp $
+*/
+#ifndef _VDBEINT_H_
+#define _VDBEINT_H_
+
+/*
+** intToKey() and keyToInt() used to transform the rowid.  But with
+** the latest versions of the design they are no-ops.
+*/
+#define keyToInt(X)   (X)
+#define intToKey(X)   (X)
+
+
+/*
+** SQL is translated into a sequence of instructions to be
+** executed by a virtual machine.  Each instruction is an instance
+** of the following structure.
+*/
+typedef struct VdbeOp Op;
+
+/*
+** Boolean values
+*/
+typedef unsigned char Bool;
+
+/*
+** A cursor is a pointer into a single BTree within a database file.
+** The cursor can seek to a BTree entry with a particular key, or
+** loop over all entries of the Btree.  You can also insert new BTree
+** entries or retrieve the key or data from the entry that the cursor
+** is currently pointing to.
+** 
+** Every cursor that the virtual machine has open is represented by an
+** instance of the following structure.
+**
+** If the Cursor.isTriggerRow flag is set it means that this cursor is
+** really a single row that represents the NEW or OLD pseudo-table of
+** a row trigger.  The data for the row is stored in Cursor.pData and
+** the rowid is in Cursor.iKey.
+*/
+struct Cursor {
+  BtCursor *pCursor;    /* The cursor structure of the backend */
+  int iDb;              /* Index of cursor database in db->aDb[] (or -1) */
+  i64 lastRowid;        /* Last rowid from a Next or NextIdx operation */
+  i64 nextRowid;        /* Next rowid returned by OP_NewRowid */
+  Bool zeroed;          /* True if zeroed out and ready for reuse */
+  Bool rowidIsValid;    /* True if lastRowid is valid */
+  Bool atFirst;         /* True if pointing to first entry */
+  Bool useRandomRowid;  /* Generate new record numbers semi-randomly */
+  Bool nullRow;         /* True if pointing to a row with no data */
+  Bool nextRowidValid;  /* True if the nextRowid field is valid */
+  Bool pseudoTable;     /* This is a NEW or OLD pseudo-tables of a trigger */
+  Bool ephemPseudoTable;
+  Bool deferredMoveto;  /* A call to sqlite3BtreeMoveto() is needed */
+  Bool isTable;         /* True if a table requiring integer keys */
+  Bool isIndex;         /* True if an index containing keys only - no data */
+  u8 bogusIncrKey;      /* Something for pIncrKey to point to if pKeyInfo==0 */
+  i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
+  Btree *pBt;           /* Separate file holding temporary table */
+  int nData;            /* Number of bytes in pData */
+  char *pData;          /* Data for a NEW or OLD pseudo-table */
+  i64 iKey;             /* Key for the NEW or OLD pseudo-table row */
+  u8 *pIncrKey;         /* Pointer to pKeyInfo->incrKey */
+  KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */
+  int nField;           /* Number of fields in the header */
+  i64 seqCount;         /* Sequence counter */
+  sqlite3_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
+  const sqlite3_module *pModule;     /* Module for cursor pVtabCursor */
+
+  /* Cached information about the header for the data record that the
+  ** cursor is currently pointing to.  Only valid if cacheValid is true.
+  ** aRow might point to (ephemeral) data for the current row, or it might
+  ** be NULL.
+  */
+  int cacheStatus;      /* Cache is valid if this matches Vdbe.cacheCtr */
+  int payloadSize;      /* Total number of bytes in the record */
+  u32 *aType;           /* Type values for all entries in the record */
+  u32 *aOffset;         /* Cached offsets to the start of each columns data */
+  u8 *aRow;             /* Data for the current row, if all on one page */
+};
+typedef struct Cursor Cursor;
+
+/*
+** A value for Cursor.cacheValid that means the cache is always invalid.
+*/
+#define CACHE_STALE 0
+
+/*
+** Internally, the vdbe manipulates nearly all SQL values as Mem
+** structures. Each Mem struct may cache multiple representations (string,
+** integer etc.) of the same value.  A value (and therefore Mem structure)
+** has the following properties:
+**
+** Each value has a manifest type. The manifest type of the value stored
+** in a Mem struct is returned by the MemType(Mem*) macro. The type is
+** one of SQLITE_NULL, SQLITE_INTEGER, SQLITE_REAL, SQLITE_TEXT or
+** SQLITE_BLOB.
+*/
+struct Mem {
+  union {
+    i64 i;              /* Integer value. Or FuncDef* when flags==MEM_Agg */
+    FuncDef *pDef;      /* Used only when flags==MEM_Agg */
+  } u;
+  double r;           /* Real value */
+  sqlite3 *db;        /* The associated database connection */
+  char *z;            /* String or BLOB value */
+  int n;              /* Number of characters in string value, excluding '\0' */
+  u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
+  u8  type;           /* One of SQLITE_NULL, SQLITE_TEXT, SQLITE_INTEGER, etc */
+  u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
+  void (*xDel)(void *);  /* If not null, call this function to delete Mem.z */
+  char *zMalloc;      /* Dynamic buffer allocated by sqlite3_malloc() */
+};
+
+/* One or more of the following flags are set to indicate the validOK
+** representations of the value stored in the Mem struct.
+**
+** If the MEM_Null flag is set, then the value is an SQL NULL value.
+** No other flags may be set in this case.
+**
+** If the MEM_Str flag is set then Mem.z points at a string representation.
+** Usually this is encoded in the same unicode encoding as the main
+** database (see below for exceptions). If the MEM_Term flag is also
+** set, then the string is nul terminated. The MEM_Int and MEM_Real 
+** flags may coexist with the MEM_Str flag.
+**
+** Multiple of these values can appear in Mem.flags.  But only one
+** at a time can appear in Mem.type.
+*/
+#define MEM_Null      0x0001   /* Value is NULL */
+#define MEM_Str       0x0002   /* Value is a string */
+#define MEM_Int       0x0004   /* Value is an integer */
+#define MEM_Real      0x0008   /* Value is a real number */
+#define MEM_Blob      0x0010   /* Value is a BLOB */
+
+#define MemSetTypeFlag(p, f) \
+  ((p)->flags = ((p)->flags&~(MEM_Int|MEM_Real|MEM_Null|MEM_Blob|MEM_Str))|f)
+
+/* Whenever Mem contains a valid string or blob representation, one of
+** the following flags must be set to determine the memory management
+** policy for Mem.z.  The MEM_Term flag tells us whether or not the
+** string is \000 or \u0000 terminated
+*/
+#define MEM_Term      0x0020   /* String rep is nul terminated */
+#define MEM_Dyn       0x0040   /* Need to call sqliteFree() on Mem.z */
+#define MEM_Static    0x0080   /* Mem.z points to a static string */
+#define MEM_Ephem     0x0100   /* Mem.z points to an ephemeral string */
+#define MEM_Agg       0x0400   /* Mem.z points to an agg function context */
+#define MEM_Zero      0x0800   /* Mem.i contains count of 0s appended to blob */
+
+#ifdef SQLITE_OMIT_INCRBLOB
+  #undef MEM_Zero
+  #define MEM_Zero 0x0000
+#endif
+
+
+/* A VdbeFunc is just a FuncDef (defined in sqliteInt.h) that contains
+** additional information about auxiliary information bound to arguments
+** of the function.  This is used to implement the sqlite3_get_auxdata()
+** and sqlite3_set_auxdata() APIs.  The "auxdata" is some auxiliary data
+** that can be associated with a constant argument to a function.  This
+** allows functions such as "regexp" to compile their constant regular
+** expression argument once and reused the compiled code for multiple
+** invocations.
+*/
+struct VdbeFunc {
+  FuncDef *pFunc;               /* The definition of the function */
+  int nAux;                     /* Number of entries allocated for apAux[] */
+  struct AuxData {
+    void *pAux;                   /* Aux data for the i-th argument */
+    void (*xDelete)(void *);      /* Destructor for the aux data */
+  } apAux[1];                   /* One slot for each function argument */
+};
+
+/*
+** The "context" argument for a installable function.  A pointer to an
+** instance of this structure is the first argument to the routines used
+** implement the SQL functions.
+**
+** There is a typedef for this structure in sqlite.h.  So all routines,
+** even the public interface to SQLite, can use a pointer to this structure.
+** But this file is the only place where the internal details of this
+** structure are known.
+**
+** This structure is defined inside of vdbeInt.h because it uses substructures
+** (Mem) which are only defined there.
+*/
+struct sqlite3_context {
+  FuncDef *pFunc;       /* Pointer to function information.  MUST BE FIRST */
+  VdbeFunc *pVdbeFunc;  /* Auxilary data, if created. */
+  Mem s;                /* The return value is stored here */
+  Mem *pMem;            /* Memory cell used to store aggregate context */
+  int isError;          /* Error code returned by the function. */
+  CollSeq *pColl;       /* Collating sequence */
+};
+
+/*
+** A Set structure is used for quick testing to see if a value
+** is part of a small set.  Sets are used to implement code like
+** this:
+**            x.y IN ('hi','hoo','hum')
+*/
+typedef struct Set Set;
+struct Set {
+  Hash hash;             /* A set is just a hash table */
+  HashElem *prev;        /* Previously accessed hash elemen */
+};
+
+/*
+** A FifoPage structure holds a single page of valves.  Pages are arranged
+** in a list.
+*/
+typedef struct FifoPage FifoPage;
+struct FifoPage {
+  int nSlot;         /* Number of entries aSlot[] */
+  int iWrite;        /* Push the next value into this entry in aSlot[] */
+  int iRead;         /* Read the next value from this entry in aSlot[] */
+  FifoPage *pNext;   /* Next page in the fifo */
+  i64 aSlot[1];      /* One or more slots for rowid values */
+};
+
+/*
+** The Fifo structure is typedef-ed in vdbeInt.h.  But the implementation
+** of that structure is private to this file.
+**
+** The Fifo structure describes the entire fifo.  
+*/
+typedef struct Fifo Fifo;
+struct Fifo {
+  int nEntry;         /* Total number of entries */
+  sqlite3 *db;        /* The associated database connection */
+  FifoPage *pFirst;   /* First page on the list */
+  FifoPage *pLast;    /* Last page on the list */
+};
+
+/*
+** A Context stores the last insert rowid, the last statement change count,
+** and the current statement change count (i.e. changes since last statement).
+** The current keylist is also stored in the context.
+** Elements of Context structure type make up the ContextStack, which is
+** updated by the ContextPush and ContextPop opcodes (used by triggers).
+** The context is pushed before executing a trigger a popped when the
+** trigger finishes.
+*/
+typedef struct Context Context;
+struct Context {
+  i64 lastRowid;    /* Last insert rowid (sqlite3.lastRowid) */
+  int nChange;      /* Statement changes (Vdbe.nChanges)     */
+  Fifo sFifo;       /* Records that will participate in a DELETE or UPDATE */
+};
+
+/*
+** An instance of the virtual machine.  This structure contains the complete
+** state of the virtual machine.
+**
+** The "sqlite3_stmt" structure pointer that is returned by sqlite3_compile()
+** is really a pointer to an instance of this structure.
+**
+** The Vdbe.inVtabMethod variable is set to non-zero for the duration of
+** any virtual table method invocations made by the vdbe program. It is
+** set to 2 for xDestroy method calls and 1 for all other methods. This
+** variable is used for two purposes: to allow xDestroy methods to execute
+** "DROP TABLE" statements and to prevent some nasty side effects of
+** malloc failure when SQLite is invoked recursively by a virtual table 
+** method function.
+*/
+struct Vdbe {
+  sqlite3 *db;        /* The whole database */
+  Vdbe *pPrev,*pNext; /* Linked list of VDBEs with the same Vdbe.db */
+  int nOp;            /* Number of instructions in the program */
+  int nOpAlloc;       /* Number of slots allocated for aOp[] */
+  Op *aOp;            /* Space to hold the virtual machine's program */
+  int nLabel;         /* Number of labels used */
+  int nLabelAlloc;    /* Number of slots allocated in aLabel[] */
+  int *aLabel;        /* Space to hold the labels */
+  Mem **apArg;        /* Arguments to currently executing user function */
+  Mem *aColName;      /* Column names to return */
+  int nCursor;        /* Number of slots in apCsr[] */
+  Cursor **apCsr;     /* One element of this array for each open cursor */
+  int nVar;           /* Number of entries in aVar[] */
+  Mem *aVar;          /* Values for the OP_Variable opcode. */
+  char **azVar;       /* Name of variables */
+  int okVar;          /* True if azVar[] has been initialized */
+  int magic;              /* Magic number for sanity checking */
+  int nMem;               /* Number of memory locations currently allocated */
+  Mem *aMem;              /* The memory locations */
+  int nCallback;          /* Number of callbacks invoked so far */
+  int cacheCtr;           /* Cursor row cache generation counter */
+  Fifo sFifo;             /* A list of ROWIDs */
+  int contextStackTop;    /* Index of top element in the context stack */
+  int contextStackDepth;  /* The size of the "context" stack */
+  Context *contextStack;  /* Stack used by opcodes ContextPush & ContextPop*/
+  int pc;                 /* The program counter */
+  int rc;                 /* Value to return */
+  unsigned uniqueCnt;     /* Used by OP_MakeRecord when P2!=0 */
+  int errorAction;        /* Recovery action to do in case of an error */
+  int inTempTrans;        /* True if temp database is transactioned */
+  int nResColumn;         /* Number of columns in one row of the result set */
+  char **azResColumn;     /* Values for one row of result */ 
+  char *zErrMsg;          /* Error message written here */
+  Mem *pResultSet;        /* Pointer to an array of results */
+  u8 explain;             /* True if EXPLAIN present on SQL command */
+  u8 changeCntOn;         /* True to update the change-counter */
+  u8 expired;             /* True if the VM needs to be recompiled */
+  u8 minWriteFileFormat;  /* Minimum file format for writable database files */
+  u8 inVtabMethod;        /* See comments above */
+  int nChange;            /* Number of db changes made since last reset */
+  i64 startTime;          /* Time when query started - used for profiling */
+  int btreeMask;          /* Bitmask of db->aDb[] entries referenced */
+  BtreeMutexArray aMutex; /* An array of Btree used here and needing locks */
+  int nSql;             /* Number of bytes in zSql */
+  char *zSql;           /* Text of the SQL statement that generated this */
+#ifdef SQLITE_DEBUG
+  FILE *trace;        /* Write an execution trace here, if not NULL */
+#endif
+  int openedStatement;  /* True if this VM has opened a statement journal */
+#ifdef SQLITE_SSE
+  int fetchId;          /* Statement number used by sqlite3_fetch_statement */
+  int lru;              /* Counter used for LRU cache replacement */
+#endif
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  Vdbe *pLruPrev;
+  Vdbe *pLruNext;
+#endif
+};
+
+/*
+** An instance of the following structure holds information about a
+** single index record that has already been parsed out into individual
+** values.
+**
+** A record is an object that contains one or more fields of data.
+** Records are used to store the content of a table row and to store
+** the key of an index.  A blob encoding of a record is created by
+** the OP_MakeRecord opcode of the VDBE and is disassemblied by the
+** OP_Column opcode.
+**
+** This structure holds a record that has already been disassembled
+** into its constitutent fields.
+*/
+struct UnpackedRecord {
+  KeyInfo *pKeyInfo;  /* Collation and sort-order information */
+  u16 nField;         /* Number of entries in apMem[] */
+  u8 needFree;        /* True if memory obtained from sqlite3_malloc() */
+  u8 needDestroy;     /* True if apMem[]s should be destroyed on close */
+  Mem *aMem;          /* Values */
+};
+
+/*
+** The following are allowed values for Vdbe.magic
+*/
+#define VDBE_MAGIC_INIT     0x26bceaa5    /* Building a VDBE program */
+#define VDBE_MAGIC_RUN      0xbdf20da3    /* VDBE is ready to execute */
+#define VDBE_MAGIC_HALT     0x519c2973    /* VDBE has completed execution */
+#define VDBE_MAGIC_DEAD     0xb606c3c8    /* The VDBE has been deallocated */
+
+/*
+** Function prototypes
+*/
+void sqlite3VdbeFreeCursor(Vdbe *, Cursor*);
+void sqliteVdbePopStack(Vdbe*,int);
+int sqlite3VdbeCursorMoveto(Cursor*);
+#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
+void sqlite3VdbePrintOp(FILE*, int, Op*);
+#endif
+int sqlite3VdbeSerialTypeLen(u32);
+u32 sqlite3VdbeSerialType(Mem*, int);
+int sqlite3VdbeSerialPut(unsigned char*, int, Mem*, int);
+int sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
+void sqlite3VdbeDeleteAuxData(VdbeFunc*, int);
+
+int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
+int sqlite3VdbeIdxKeyCompare(Cursor*,UnpackedRecord *,int,const unsigned char*,int*);
+int sqlite3VdbeIdxRowid(BtCursor *, i64 *);
+int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
+int sqlite3VdbeIdxRowidLen(const u8*, int, int*);
+int sqlite3VdbeExec(Vdbe*);
+int sqlite3VdbeList(Vdbe*);
+int sqlite3VdbeHalt(Vdbe*);
+int sqlite3VdbeChangeEncoding(Mem *, int);
+int sqlite3VdbeMemTooBig(Mem*);
+int sqlite3VdbeMemCopy(Mem*, const Mem*);
+void sqlite3VdbeMemShallowCopy(Mem*, const Mem*, int);
+void sqlite3VdbeMemMove(Mem*, Mem*);
+int sqlite3VdbeMemNulTerminate(Mem*);
+int sqlite3VdbeMemSetStr(Mem*, const char*, int, u8, void(*)(void*));
+void sqlite3VdbeMemSetInt64(Mem*, i64);
+void sqlite3VdbeMemSetDouble(Mem*, double);
+void sqlite3VdbeMemSetNull(Mem*);
+void sqlite3VdbeMemSetZeroBlob(Mem*,int);
+int sqlite3VdbeMemMakeWriteable(Mem*);
+int sqlite3VdbeMemStringify(Mem*, int);
+i64 sqlite3VdbeIntValue(Mem*);
+int sqlite3VdbeMemIntegerify(Mem*);
+double sqlite3VdbeRealValue(Mem*);
+void sqlite3VdbeIntegerAffinity(Mem*);
+int sqlite3VdbeMemRealify(Mem*);
+int sqlite3VdbeMemNumerify(Mem*);
+int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
+void sqlite3VdbeMemRelease(Mem *p);
+void sqlite3VdbeMemReleaseExternal(Mem *p);
+int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
+const char *sqlite3OpcodeName(int);
+int sqlite3VdbeOpcodeHasProperty(int, int);
+int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+int sqlite3VdbeReleaseBuffers(Vdbe *p);
+#endif
+
+#ifndef NDEBUG
+  void sqlite3VdbeMemSanity(Mem*);
+#endif
+int sqlite3VdbeMemTranslate(Mem*, u8);
+#ifdef SQLITE_DEBUG
+  void sqlite3VdbePrintSql(Vdbe*);
+  void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
+#endif
+int sqlite3VdbeMemHandleBom(Mem *pMem);
+void sqlite3VdbeFifoInit(Fifo*, sqlite3*);
+int sqlite3VdbeFifoPush(Fifo*, i64);
+int sqlite3VdbeFifoPop(Fifo*, i64*);
+void sqlite3VdbeFifoClear(Fifo*);
+
+#ifndef SQLITE_OMIT_INCRBLOB
+  int sqlite3VdbeMemExpandBlob(Mem *);
+#else
+  #define sqlite3VdbeMemExpandBlob(x) SQLITE_OK
+#endif
+
+#endif /* !defined(_VDBEINT_H_) */
diff --git a/third_party/sqlite/src/vdbeapi.c b/third_party/sqlite/src/vdbeapi.c
new file mode 100755
index 0000000..880c4ae
--- /dev/null
+++ b/third_party/sqlite/src/vdbeapi.c
@@ -0,0 +1,1275 @@
+/*
+** 2004 May 26
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains code use to implement APIs that are part of the
+** VDBE.
+**
+** $Id: vdbeapi.c,v 1.138 2008/08/02 03:50:39 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "vdbeInt.h"
+
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+/*
+** The following structure contains pointers to the end points of a
+** doubly-linked list of all compiled SQL statements that may be holding
+** buffers eligible for release when the sqlite3_release_memory() interface is
+** invoked. Access to this list is protected by the SQLITE_MUTEX_STATIC_LRU2
+** mutex.
+**
+** Statements are added to the end of this list when sqlite3_reset() is
+** called. They are removed either when sqlite3_step() or sqlite3_finalize()
+** is called. When statements are added to this list, the associated 
+** register array (p->aMem[1..p->nMem]) may contain dynamic buffers that
+** can be freed using sqlite3VdbeReleaseMemory().
+**
+** When statements are added or removed from this list, the mutex
+** associated with the Vdbe being added or removed (Vdbe.db->mutex) is
+** already held. The LRU2 mutex is then obtained, blocking if necessary,
+** the linked-list pointers manipulated and the LRU2 mutex relinquished.
+*/
+struct StatementLruList {
+  Vdbe *pFirst;
+  Vdbe *pLast;
+};
+static struct StatementLruList sqlite3LruStatements;
+
+/*
+** Check that the list looks to be internally consistent. This is used
+** as part of an assert() statement as follows:
+**
+**   assert( stmtLruCheck() );
+*/
+#ifndef NDEBUG
+static int stmtLruCheck(){
+  Vdbe *p;
+  for(p=sqlite3LruStatements.pFirst; p; p=p->pLruNext){
+    assert(p->pLruNext || p==sqlite3LruStatements.pLast);
+    assert(!p->pLruNext || p->pLruNext->pLruPrev==p);
+    assert(p->pLruPrev || p==sqlite3LruStatements.pFirst);
+    assert(!p->pLruPrev || p->pLruPrev->pLruNext==p);
+  }
+  return 1;
+}
+#endif
+
+/*
+** Add vdbe p to the end of the statement lru list. It is assumed that
+** p is not already part of the list when this is called. The lru list
+** is protected by the SQLITE_MUTEX_STATIC_LRU mutex.
+*/
+static void stmtLruAdd(Vdbe *p){
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+
+  if( p->pLruPrev || p->pLruNext || sqlite3LruStatements.pFirst==p ){
+    sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+    return;
+  }
+
+  assert( stmtLruCheck() );
+
+  if( !sqlite3LruStatements.pFirst ){
+    assert( !sqlite3LruStatements.pLast );
+    sqlite3LruStatements.pFirst = p;
+    sqlite3LruStatements.pLast = p;
+  }else{
+    assert( !sqlite3LruStatements.pLast->pLruNext );
+    p->pLruPrev = sqlite3LruStatements.pLast;
+    sqlite3LruStatements.pLast->pLruNext = p;
+    sqlite3LruStatements.pLast = p;
+  }
+
+  assert( stmtLruCheck() );
+
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+}
+
+/*
+** Assuming the SQLITE_MUTEX_STATIC_LRU2 mutext is already held, remove
+** statement p from the least-recently-used statement list. If the 
+** statement is not currently part of the list, this call is a no-op.
+*/
+static void stmtLruRemoveNomutex(Vdbe *p){
+  if( p->pLruPrev || p->pLruNext || p==sqlite3LruStatements.pFirst ){
+    assert( stmtLruCheck() );
+    if( p->pLruNext ){
+      p->pLruNext->pLruPrev = p->pLruPrev;
+    }else{
+      sqlite3LruStatements.pLast = p->pLruPrev;
+    }
+    if( p->pLruPrev ){
+      p->pLruPrev->pLruNext = p->pLruNext;
+    }else{
+      sqlite3LruStatements.pFirst = p->pLruNext;
+    }
+    p->pLruNext = 0;
+    p->pLruPrev = 0;
+    assert( stmtLruCheck() );
+  }
+}
+
+/*
+** Assuming the SQLITE_MUTEX_STATIC_LRU2 mutext is not held, remove
+** statement p from the least-recently-used statement list. If the 
+** statement is not currently part of the list, this call is a no-op.
+*/
+static void stmtLruRemove(Vdbe *p){
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+  stmtLruRemoveNomutex(p);
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+}
+
+/*
+** Try to release n bytes of memory by freeing buffers associated 
+** with the memory registers of currently unused vdbes.
+*/
+int sqlite3VdbeReleaseMemory(int n){
+  Vdbe *p;
+  Vdbe *pNext;
+  int nFree = 0;
+
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+  for(p=sqlite3LruStatements.pFirst; p && nFree<n; p=pNext){
+    pNext = p->pLruNext;
+
+    /* For each statement handle in the lru list, attempt to obtain the
+    ** associated database mutex. If it cannot be obtained, continue
+    ** to the next statement handle. It is not possible to block on
+    ** the database mutex - that could cause deadlock.
+    */
+    if( SQLITE_OK==sqlite3_mutex_try(p->db->mutex) ){
+      nFree += sqlite3VdbeReleaseBuffers(p);
+      stmtLruRemoveNomutex(p);
+      sqlite3_mutex_leave(p->db->mutex);
+    }
+  }
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+
+  return nFree;
+}
+
+/*
+** Call sqlite3Reprepare() on the statement. Remove it from the
+** lru list before doing so, as Reprepare() will free all the
+** memory register buffers anyway.
+*/
+int vdbeReprepare(Vdbe *p){
+  stmtLruRemove(p);
+  return sqlite3Reprepare(p);
+}
+
+#else       /* !SQLITE_ENABLE_MEMORY_MANAGEMENT */
+  #define stmtLruRemove(x)
+  #define stmtLruAdd(x)
+  #define vdbeReprepare(x) sqlite3Reprepare(x)
+#endif
+
+
+/*
+** Return TRUE (non-zero) of the statement supplied as an argument needs
+** to be recompiled.  A statement needs to be recompiled whenever the
+** execution environment changes in a way that would alter the program
+** that sqlite3_prepare() generates.  For example, if new functions or
+** collating sequences are registered or if an authorizer function is
+** added or changed.
+*/
+int sqlite3_expired(sqlite3_stmt *pStmt){
+  Vdbe *p = (Vdbe*)pStmt;
+  return p==0 || p->expired;
+}
+
+/*
+** The following routine destroys a virtual machine that is created by
+** the sqlite3_compile() routine. The integer returned is an SQLITE_
+** success/failure code that describes the result of executing the virtual
+** machine.
+**
+** This routine sets the error code and string returned by
+** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
+*/
+int sqlite3_finalize(sqlite3_stmt *pStmt){
+  int rc;
+  if( pStmt==0 ){
+    rc = SQLITE_OK;
+  }else{
+    Vdbe *v = (Vdbe*)pStmt;
+#ifndef SQLITE_MUTEX_NOOP
+    sqlite3_mutex *mutex = v->db->mutex;
+#endif
+    sqlite3_mutex_enter(mutex);
+    stmtLruRemove(v);
+    rc = sqlite3VdbeFinalize(v);
+    sqlite3_mutex_leave(mutex);
+  }
+  return rc;
+}
+
+/*
+** Terminate the current execution of an SQL statement and reset it
+** back to its starting state so that it can be reused. A success code from
+** the prior execution is returned.
+**
+** This routine sets the error code and string returned by
+** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
+*/
+int sqlite3_reset(sqlite3_stmt *pStmt){
+  int rc;
+  if( pStmt==0 ){
+    rc = SQLITE_OK;
+  }else{
+    Vdbe *v = (Vdbe*)pStmt;
+    sqlite3_mutex_enter(v->db->mutex);
+    rc = sqlite3VdbeReset(v);
+    stmtLruAdd(v);
+    sqlite3VdbeMakeReady(v, -1, 0, 0, 0);
+    assert( (rc & (v->db->errMask))==rc );
+    sqlite3_mutex_leave(v->db->mutex);
+  }
+  return rc;
+}
+
+/*
+** Set all the parameters in the compiled SQL statement to NULL.
+*/
+int sqlite3_clear_bindings(sqlite3_stmt *pStmt){
+  int i;
+  int rc = SQLITE_OK;
+  Vdbe *p = (Vdbe*)pStmt;
+#ifndef SQLITE_MUTEX_NOOP
+  sqlite3_mutex *mutex = ((Vdbe*)pStmt)->db->mutex;
+#endif
+  sqlite3_mutex_enter(mutex);
+  for(i=0; i<p->nVar; i++){
+    sqlite3VdbeMemRelease(&p->aVar[i]);
+    p->aVar[i].flags = MEM_Null;
+  }
+  sqlite3_mutex_leave(mutex);
+  return rc;
+}
+
+
+/**************************** sqlite3_value_  *******************************
+** The following routines extract information from a Mem or sqlite3_value
+** structure.
+*/
+const void *sqlite3_value_blob(sqlite3_value *pVal){
+  Mem *p = (Mem*)pVal;
+  if( p->flags & (MEM_Blob|MEM_Str) ){
+    sqlite3VdbeMemExpandBlob(p);
+    p->flags &= ~MEM_Str;
+    p->flags |= MEM_Blob;
+    return p->z;
+  }else{
+    return sqlite3_value_text(pVal);
+  }
+}
+int sqlite3_value_bytes(sqlite3_value *pVal){
+  return sqlite3ValueBytes(pVal, SQLITE_UTF8);
+}
+int sqlite3_value_bytes16(sqlite3_value *pVal){
+  return sqlite3ValueBytes(pVal, SQLITE_UTF16NATIVE);
+}
+double sqlite3_value_double(sqlite3_value *pVal){
+  return sqlite3VdbeRealValue((Mem*)pVal);
+}
+int sqlite3_value_int(sqlite3_value *pVal){
+  return sqlite3VdbeIntValue((Mem*)pVal);
+}
+sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
+  return sqlite3VdbeIntValue((Mem*)pVal);
+}
+const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
+  return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_value_text16(sqlite3_value* pVal){
+  return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
+}
+const void *sqlite3_value_text16be(sqlite3_value *pVal){
+  return sqlite3ValueText(pVal, SQLITE_UTF16BE);
+}
+const void *sqlite3_value_text16le(sqlite3_value *pVal){
+  return sqlite3ValueText(pVal, SQLITE_UTF16LE);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+int sqlite3_value_type(sqlite3_value* pVal){
+  return pVal->type;
+}
+
+/**************************** sqlite3_result_  *******************************
+** The following routines are used by user-defined functions to specify
+** the function result.
+*/
+void sqlite3_result_blob(
+  sqlite3_context *pCtx, 
+  const void *z, 
+  int n, 
+  void (*xDel)(void *)
+){
+  assert( n>=0 );
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemSetStr(&pCtx->s, z, n, 0, xDel);
+}
+void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemSetDouble(&pCtx->s, rVal);
+}
+void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  pCtx->isError = SQLITE_ERROR;
+  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
+}
+#ifndef SQLITE_OMIT_UTF16
+void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  pCtx->isError = SQLITE_ERROR;
+  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
+}
+#endif
+void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemSetInt64(&pCtx->s, (i64)iVal);
+}
+void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemSetInt64(&pCtx->s, iVal);
+}
+void sqlite3_result_null(sqlite3_context *pCtx){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemSetNull(&pCtx->s);
+}
+void sqlite3_result_text(
+  sqlite3_context *pCtx, 
+  const char *z, 
+  int n,
+  void (*xDel)(void *)
+){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, xDel);
+}
+#ifndef SQLITE_OMIT_UTF16
+void sqlite3_result_text16(
+  sqlite3_context *pCtx, 
+  const void *z, 
+  int n, 
+  void (*xDel)(void *)
+){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, xDel);
+}
+void sqlite3_result_text16be(
+  sqlite3_context *pCtx, 
+  const void *z, 
+  int n, 
+  void (*xDel)(void *)
+){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16BE, xDel);
+}
+void sqlite3_result_text16le(
+  sqlite3_context *pCtx, 
+  const void *z, 
+  int n, 
+  void (*xDel)(void *)
+){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16LE, xDel);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemCopy(&pCtx->s, pValue);
+}
+void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemSetZeroBlob(&pCtx->s, n);
+}
+void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
+  pCtx->isError = errCode;
+}
+
+/* Force an SQLITE_TOOBIG error. */
+void sqlite3_result_error_toobig(sqlite3_context *pCtx){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  pCtx->isError = SQLITE_TOOBIG;
+  sqlite3VdbeMemSetStr(&pCtx->s, "string or blob too big", -1, 
+                       SQLITE_UTF8, SQLITE_STATIC);
+}
+
+/* An SQLITE_NOMEM error. */
+void sqlite3_result_error_nomem(sqlite3_context *pCtx){
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  sqlite3VdbeMemSetNull(&pCtx->s);
+  pCtx->isError = SQLITE_NOMEM;
+  pCtx->s.db->mallocFailed = 1;
+}
+
+/*
+** Execute the statement pStmt, either until a row of data is ready, the
+** statement is completely executed or an error occurs.
+**
+** This routine implements the bulk of the logic behind the sqlite_step()
+** API.  The only thing omitted is the automatic recompile if a 
+** schema change has occurred.  That detail is handled by the
+** outer sqlite3_step() wrapper procedure.
+*/
+static int sqlite3Step(Vdbe *p){
+  sqlite3 *db;
+  int rc;
+
+  assert(p);
+  if( p->magic!=VDBE_MAGIC_RUN ){
+    return SQLITE_MISUSE;
+  }
+
+  /* Assert that malloc() has not failed */
+  db = p->db;
+  assert( !db->mallocFailed );
+
+  if( p->pc<=0 && p->expired ){
+    if( p->rc==SQLITE_OK ){
+      p->rc = SQLITE_SCHEMA;
+    }
+    rc = SQLITE_ERROR;
+    goto end_of_step;
+  }
+  if( sqlite3SafetyOn(db) ){
+    p->rc = SQLITE_MISUSE;
+    return SQLITE_MISUSE;
+  }
+  if( p->pc<0 ){
+    /* If there are no other statements currently running, then
+    ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
+    ** from interrupting a statement that has not yet started.
+    */
+    if( db->activeVdbeCnt==0 ){
+      db->u1.isInterrupted = 0;
+    }
+
+#ifndef SQLITE_OMIT_TRACE
+    if( db->xProfile && !db->init.busy ){
+      double rNow;
+      sqlite3OsCurrentTime(db->pVfs, &rNow);
+      p->startTime = (rNow - (int)rNow)*3600.0*24.0*1000000000.0;
+    }
+#endif
+
+    db->activeVdbeCnt++;
+    p->pc = 0;
+    stmtLruRemove(p);
+  }
+#ifndef SQLITE_OMIT_EXPLAIN
+  if( p->explain ){
+    rc = sqlite3VdbeList(p);
+  }else
+#endif /* SQLITE_OMIT_EXPLAIN */
+  {
+    rc = sqlite3VdbeExec(p);
+  }
+
+  if( sqlite3SafetyOff(db) ){
+    rc = SQLITE_MISUSE;
+  }
+
+#ifndef SQLITE_OMIT_TRACE
+  /* Invoke the profile callback if there is one
+  */
+  if( rc!=SQLITE_ROW && db->xProfile && !db->init.busy && p->nOp>0
+           && p->aOp[0].opcode==OP_Trace && p->aOp[0].p4.z!=0 ){
+    double rNow;
+    u64 elapseTime;
+
+    sqlite3OsCurrentTime(db->pVfs, &rNow);
+    elapseTime = (rNow - (int)rNow)*3600.0*24.0*1000000000.0 - p->startTime;
+    db->xProfile(db->pProfileArg, p->aOp[0].p4.z, elapseTime);
+  }
+#endif
+
+  db->errCode = rc;
+  /*sqlite3Error(p->db, rc, 0);*/
+  p->rc = sqlite3ApiExit(p->db, p->rc);
+end_of_step:
+  assert( (rc&0xff)==rc );
+  if( p->zSql && (rc&0xff)<SQLITE_ROW ){
+    /* This behavior occurs if sqlite3_prepare_v2() was used to build
+    ** the prepared statement.  Return error codes directly */
+    p->db->errCode = p->rc;
+    /* sqlite3Error(p->db, p->rc, 0); */
+    return p->rc;
+  }else{
+    /* This is for legacy sqlite3_prepare() builds and when the code
+    ** is SQLITE_ROW or SQLITE_DONE */
+    return rc;
+  }
+}
+
+/*
+** This is the top-level implementation of sqlite3_step().  Call
+** sqlite3Step() to do most of the work.  If a schema error occurs,
+** call sqlite3Reprepare() and try again.
+*/
+#ifdef SQLITE_OMIT_PARSER
+int sqlite3_step(sqlite3_stmt *pStmt){
+  int rc = SQLITE_MISUSE;
+  if( pStmt ){
+    Vdbe *v;
+    v = (Vdbe*)pStmt;
+    sqlite3_mutex_enter(v->db->mutex);
+    rc = sqlite3Step(v);
+    sqlite3_mutex_leave(v->db->mutex);
+  }
+  return rc;
+}
+#else
+int sqlite3_step(sqlite3_stmt *pStmt){
+  int rc = SQLITE_MISUSE;
+  if( pStmt ){
+    int cnt = 0;
+    Vdbe *v = (Vdbe*)pStmt;
+    sqlite3 *db = v->db;
+    sqlite3_mutex_enter(db->mutex);
+    while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
+           && cnt++ < 5
+           && vdbeReprepare(v) ){
+      sqlite3_reset(pStmt);
+      v->expired = 0;
+    }
+    if( rc==SQLITE_SCHEMA && v->zSql && db->pErr ){
+      /* This case occurs after failing to recompile an sql statement. 
+      ** The error message from the SQL compiler has already been loaded 
+      ** into the database handle. This block copies the error message 
+      ** from the database handle into the statement and sets the statement
+      ** program counter to 0 to ensure that when the statement is 
+      ** finalized or reset the parser error message is available via
+      ** sqlite3_errmsg() and sqlite3_errcode().
+      */
+      const char *zErr = (const char *)sqlite3_value_text(db->pErr); 
+      sqlite3DbFree(db, v->zErrMsg);
+      if( !db->mallocFailed ){
+        v->zErrMsg = sqlite3DbStrDup(db, zErr);
+      } else {
+        v->zErrMsg = 0;
+        v->rc = SQLITE_NOMEM;
+      }
+    }
+    rc = sqlite3ApiExit(db, rc);
+    sqlite3_mutex_leave(db->mutex);
+  }
+  return rc;
+}
+#endif
+
+/*
+** Extract the user data from a sqlite3_context structure and return a
+** pointer to it.
+*/
+void *sqlite3_user_data(sqlite3_context *p){
+  assert( p && p->pFunc );
+  return p->pFunc->pUserData;
+}
+
+/*
+** Extract the user data from a sqlite3_context structure and return a
+** pointer to it.
+*/
+sqlite3 *sqlite3_context_db_handle(sqlite3_context *p){
+  assert( p && p->pFunc );
+  return p->s.db;
+}
+
+/*
+** The following is the implementation of an SQL function that always
+** fails with an error message stating that the function is used in the
+** wrong context.  The sqlite3_overload_function() API might construct
+** SQL function that use this routine so that the functions will exist
+** for name resolution but are actually overloaded by the xFindFunction
+** method of virtual tables.
+*/
+void sqlite3InvalidFunction(
+  sqlite3_context *context,  /* The function calling context */
+  int argc,                  /* Number of arguments to the function */
+  sqlite3_value **argv       /* Value of each argument */
+){
+  const char *zName = context->pFunc->zName;
+  char *zErr;
+  zErr = sqlite3MPrintf(0,
+      "unable to use function %s in the requested context", zName);
+  sqlite3_result_error(context, zErr, -1);
+  sqlite3_free(zErr);
+}
+
+/*
+** Allocate or return the aggregate context for a user function.  A new
+** context is allocated on the first call.  Subsequent calls return the
+** same context that was returned on prior calls.
+*/
+void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
+  Mem *pMem;
+  assert( p && p->pFunc && p->pFunc->xStep );
+  assert( sqlite3_mutex_held(p->s.db->mutex) );
+  pMem = p->pMem;
+  if( (pMem->flags & MEM_Agg)==0 ){
+    if( nByte==0 ){
+      sqlite3VdbeMemReleaseExternal(pMem);
+      pMem->flags = MEM_Null;
+      pMem->z = 0;
+    }else{
+      sqlite3VdbeMemGrow(pMem, nByte, 0);
+      pMem->flags = MEM_Agg;
+      pMem->u.pDef = p->pFunc;
+      if( pMem->z ){
+        memset(pMem->z, 0, nByte);
+      }
+    }
+  }
+  return (void*)pMem->z;
+}
+
+/*
+** Return the auxilary data pointer, if any, for the iArg'th argument to
+** the user-function defined by pCtx.
+*/
+void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
+  VdbeFunc *pVdbeFunc;
+
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  pVdbeFunc = pCtx->pVdbeFunc;
+  if( !pVdbeFunc || iArg>=pVdbeFunc->nAux || iArg<0 ){
+    return 0;
+  }
+  return pVdbeFunc->apAux[iArg].pAux;
+}
+
+/*
+** Set the auxilary data pointer and delete function, for the iArg'th
+** argument to the user-function defined by pCtx. Any previous value is
+** deleted by calling the delete function specified when it was set.
+*/
+void sqlite3_set_auxdata(
+  sqlite3_context *pCtx, 
+  int iArg, 
+  void *pAux, 
+  void (*xDelete)(void*)
+){
+  struct AuxData *pAuxData;
+  VdbeFunc *pVdbeFunc;
+  if( iArg<0 ) goto failed;
+
+  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  pVdbeFunc = pCtx->pVdbeFunc;
+  if( !pVdbeFunc || pVdbeFunc->nAux<=iArg ){
+    int nAux = (pVdbeFunc ? pVdbeFunc->nAux : 0);
+    int nMalloc = sizeof(VdbeFunc) + sizeof(struct AuxData)*iArg;
+    pVdbeFunc = sqlite3DbRealloc(pCtx->s.db, pVdbeFunc, nMalloc);
+    if( !pVdbeFunc ){
+      goto failed;
+    }
+    pCtx->pVdbeFunc = pVdbeFunc;
+    memset(&pVdbeFunc->apAux[nAux], 0, sizeof(struct AuxData)*(iArg+1-nAux));
+    pVdbeFunc->nAux = iArg+1;
+    pVdbeFunc->pFunc = pCtx->pFunc;
+  }
+
+  pAuxData = &pVdbeFunc->apAux[iArg];
+  if( pAuxData->pAux && pAuxData->xDelete ){
+    pAuxData->xDelete(pAuxData->pAux);
+  }
+  pAuxData->pAux = pAux;
+  pAuxData->xDelete = xDelete;
+  return;
+
+failed:
+  if( xDelete ){
+    xDelete(pAux);
+  }
+}
+
+/*
+** Return the number of times the Step function of a aggregate has been 
+** called.
+**
+** This function is deprecated.  Do not use it for new code.  It is
+** provide only to avoid breaking legacy code.  New aggregate function
+** implementations should keep their own counts within their aggregate
+** context.
+*/
+int sqlite3_aggregate_count(sqlite3_context *p){
+  assert( p && p->pFunc && p->pFunc->xStep );
+  return p->pMem->n;
+}
+
+/*
+** Return the number of columns in the result set for the statement pStmt.
+*/
+int sqlite3_column_count(sqlite3_stmt *pStmt){
+  Vdbe *pVm = (Vdbe *)pStmt;
+  return pVm ? pVm->nResColumn : 0;
+}
+
+/*
+** Return the number of values available from the current row of the
+** currently executing statement pStmt.
+*/
+int sqlite3_data_count(sqlite3_stmt *pStmt){
+  Vdbe *pVm = (Vdbe *)pStmt;
+  if( pVm==0 || pVm->pResultSet==0 ) return 0;
+  return pVm->nResColumn;
+}
+
+
+/*
+** Check to see if column iCol of the given statement is valid.  If
+** it is, return a pointer to the Mem for the value of that column.
+** If iCol is not valid, return a pointer to a Mem which has a value
+** of NULL.
+*/
+static Mem *columnMem(sqlite3_stmt *pStmt, int i){
+  Vdbe *pVm;
+  int vals;
+  Mem *pOut;
+
+  pVm = (Vdbe *)pStmt;
+  if( pVm && pVm->pResultSet!=0 && i<pVm->nResColumn && i>=0 ){
+    sqlite3_mutex_enter(pVm->db->mutex);
+    vals = sqlite3_data_count(pStmt);
+    pOut = &pVm->pResultSet[i];
+  }else{
+    static const Mem nullMem = {{0}, 0.0, 0, "", 0, MEM_Null, SQLITE_NULL, 0, 0, 0 };
+    if( pVm->db ){
+      sqlite3_mutex_enter(pVm->db->mutex);
+      sqlite3Error(pVm->db, SQLITE_RANGE, 0);
+    }
+    pOut = (Mem*)&nullMem;
+  }
+  return pOut;
+}
+
+/*
+** This function is called after invoking an sqlite3_value_XXX function on a 
+** column value (i.e. a value returned by evaluating an SQL expression in the
+** select list of a SELECT statement) that may cause a malloc() failure. If 
+** malloc() has failed, the threads mallocFailed flag is cleared and the result
+** code of statement pStmt set to SQLITE_NOMEM.
+**
+** Specifically, this is called from within:
+**
+**     sqlite3_column_int()
+**     sqlite3_column_int64()
+**     sqlite3_column_text()
+**     sqlite3_column_text16()
+**     sqlite3_column_real()
+**     sqlite3_column_bytes()
+**     sqlite3_column_bytes16()
+**
+** But not for sqlite3_column_blob(), which never calls malloc().
+*/
+static void columnMallocFailure(sqlite3_stmt *pStmt)
+{
+  /* If malloc() failed during an encoding conversion within an
+  ** sqlite3_column_XXX API, then set the return code of the statement to
+  ** SQLITE_NOMEM. The next call to _step() (if any) will return SQLITE_ERROR
+  ** and _finalize() will return NOMEM.
+  */
+  Vdbe *p = (Vdbe *)pStmt;
+  if( p ){
+    p->rc = sqlite3ApiExit(p->db, p->rc);
+    sqlite3_mutex_leave(p->db->mutex);
+  }
+}
+
+/**************************** sqlite3_column_  *******************************
+** The following routines are used to access elements of the current row
+** in the result set.
+*/
+const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){
+  const void *val;
+  val = sqlite3_value_blob( columnMem(pStmt,i) );
+  /* Even though there is no encoding conversion, value_blob() might
+  ** need to call malloc() to expand the result of a zeroblob() 
+  ** expression. 
+  */
+  columnMallocFailure(pStmt);
+  return val;
+}
+int sqlite3_column_bytes(sqlite3_stmt *pStmt, int i){
+  int val = sqlite3_value_bytes( columnMem(pStmt,i) );
+  columnMallocFailure(pStmt);
+  return val;
+}
+int sqlite3_column_bytes16(sqlite3_stmt *pStmt, int i){
+  int val = sqlite3_value_bytes16( columnMem(pStmt,i) );
+  columnMallocFailure(pStmt);
+  return val;
+}
+double sqlite3_column_double(sqlite3_stmt *pStmt, int i){
+  double val = sqlite3_value_double( columnMem(pStmt,i) );
+  columnMallocFailure(pStmt);
+  return val;
+}
+int sqlite3_column_int(sqlite3_stmt *pStmt, int i){
+  int val = sqlite3_value_int( columnMem(pStmt,i) );
+  columnMallocFailure(pStmt);
+  return val;
+}
+sqlite_int64 sqlite3_column_int64(sqlite3_stmt *pStmt, int i){
+  sqlite_int64 val = sqlite3_value_int64( columnMem(pStmt,i) );
+  columnMallocFailure(pStmt);
+  return val;
+}
+const unsigned char *sqlite3_column_text(sqlite3_stmt *pStmt, int i){
+  const unsigned char *val = sqlite3_value_text( columnMem(pStmt,i) );
+  columnMallocFailure(pStmt);
+  return val;
+}
+sqlite3_value *sqlite3_column_value(sqlite3_stmt *pStmt, int i){
+  sqlite3_value *pOut = columnMem(pStmt, i);
+  columnMallocFailure(pStmt);
+  return pOut;
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_text16(sqlite3_stmt *pStmt, int i){
+  const void *val = sqlite3_value_text16( columnMem(pStmt,i) );
+  columnMallocFailure(pStmt);
+  return val;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
+  int iType = sqlite3_value_type( columnMem(pStmt,i) );
+  columnMallocFailure(pStmt);
+  return iType;
+}
+
+/* The following function is experimental and subject to change or
+** removal */
+/*int sqlite3_column_numeric_type(sqlite3_stmt *pStmt, int i){
+**  return sqlite3_value_numeric_type( columnMem(pStmt,i) );
+**}
+*/
+
+/*
+** Convert the N-th element of pStmt->pColName[] into a string using
+** xFunc() then return that string.  If N is out of range, return 0.
+**
+** There are up to 5 names for each column.  useType determines which
+** name is returned.  Here are the names:
+**
+**    0      The column name as it should be displayed for output
+**    1      The datatype name for the column
+**    2      The name of the database that the column derives from
+**    3      The name of the table that the column derives from
+**    4      The name of the table column that the result column derives from
+**
+** If the result is not a simple column reference (if it is an expression
+** or a constant) then useTypes 2, 3, and 4 return NULL.
+*/
+static const void *columnName(
+  sqlite3_stmt *pStmt,
+  int N,
+  const void *(*xFunc)(Mem*),
+  int useType
+){
+  const void *ret = 0;
+  Vdbe *p = (Vdbe *)pStmt;
+  int n;
+  
+
+  if( p!=0 ){
+    n = sqlite3_column_count(pStmt);
+    if( N<n && N>=0 ){
+      N += useType*n;
+      sqlite3_mutex_enter(p->db->mutex);
+      ret = xFunc(&p->aColName[N]);
+
+      /* A malloc may have failed inside of the xFunc() call. If this
+      ** is the case, clear the mallocFailed flag and return NULL.
+      */
+      if( p->db && p->db->mallocFailed ){
+        p->db->mallocFailed = 0;
+        ret = 0;
+      }
+      sqlite3_mutex_leave(p->db->mutex);
+    }
+  }
+  return ret;
+}
+
+/*
+** Return the name of the Nth column of the result set returned by SQL
+** statement pStmt.
+*/
+const char *sqlite3_column_name(sqlite3_stmt *pStmt, int N){
+  return columnName(
+      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_NAME);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_name16(sqlite3_stmt *pStmt, int N){
+  return columnName(
+      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_NAME);
+}
+#endif
+
+/*
+** Constraint:  If you have ENABLE_COLUMN_METADATA then you must
+** not define OMIT_DECLTYPE.
+*/
+#if defined(SQLITE_OMIT_DECLTYPE) && defined(SQLITE_ENABLE_COLUMN_METADATA)
+# error "Must not define both SQLITE_OMIT_DECLTYPE \
+         and SQLITE_ENABLE_COLUMN_METADATA"
+#endif
+
+#ifndef SQLITE_OMIT_DECLTYPE
+/*
+** Return the column declaration type (if applicable) of the 'i'th column
+** of the result set of SQL statement pStmt.
+*/
+const char *sqlite3_column_decltype(sqlite3_stmt *pStmt, int N){
+  return columnName(
+      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_DECLTYPE);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_decltype16(sqlite3_stmt *pStmt, int N){
+  return columnName(
+      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_DECLTYPE);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+#endif /* SQLITE_OMIT_DECLTYPE */
+
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+/*
+** Return the name of the database from which a result column derives.
+** NULL is returned if the result column is an expression or constant or
+** anything else which is not an unabiguous reference to a database column.
+*/
+const char *sqlite3_column_database_name(sqlite3_stmt *pStmt, int N){
+  return columnName(
+      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_DATABASE);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N){
+  return columnName(
+      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_DATABASE);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+/*
+** Return the name of the table from which a result column derives.
+** NULL is returned if the result column is an expression or constant or
+** anything else which is not an unabiguous reference to a database column.
+*/
+const char *sqlite3_column_table_name(sqlite3_stmt *pStmt, int N){
+  return columnName(
+      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_TABLE);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N){
+  return columnName(
+      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_TABLE);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+/*
+** Return the name of the table column from which a result column derives.
+** NULL is returned if the result column is an expression or constant or
+** anything else which is not an unabiguous reference to a database column.
+*/
+const char *sqlite3_column_origin_name(sqlite3_stmt *pStmt, int N){
+  return columnName(
+      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_COLUMN);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_origin_name16(sqlite3_stmt *pStmt, int N){
+  return columnName(
+      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_COLUMN);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+#endif /* SQLITE_ENABLE_COLUMN_METADATA */
+
+
+/******************************* sqlite3_bind_  ***************************
+** 
+** Routines used to attach values to wildcards in a compiled SQL statement.
+*/
+/*
+** Unbind the value bound to variable i in virtual machine p. This is the 
+** the same as binding a NULL value to the column. If the "i" parameter is
+** out of range, then SQLITE_RANGE is returned. Othewise SQLITE_OK.
+**
+** The error code stored in database p->db is overwritten with the return
+** value in any case.
+*/
+static int vdbeUnbind(Vdbe *p, int i){
+  Mem *pVar;
+  if( p==0 || p->magic!=VDBE_MAGIC_RUN || p->pc>=0 ){
+    if( p ) sqlite3Error(p->db, SQLITE_MISUSE, 0);
+    return SQLITE_MISUSE;
+  }
+  if( i<1 || i>p->nVar ){
+    sqlite3Error(p->db, SQLITE_RANGE, 0);
+    return SQLITE_RANGE;
+  }
+  i--;
+  pVar = &p->aVar[i];
+  sqlite3VdbeMemRelease(pVar);
+  pVar->flags = MEM_Null;
+  sqlite3Error(p->db, SQLITE_OK, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Bind a text or BLOB value.
+*/
+static int bindText(
+  sqlite3_stmt *pStmt,   /* The statement to bind against */
+  int i,                 /* Index of the parameter to bind */
+  const void *zData,     /* Pointer to the data to be bound */
+  int nData,             /* Number of bytes of data to be bound */
+  void (*xDel)(void*),   /* Destructor for the data */
+  int encoding           /* Encoding for the data */
+){
+  Vdbe *p = (Vdbe *)pStmt;
+  Mem *pVar;
+  int rc;
+
+  if( p==0 ){
+    return SQLITE_MISUSE;
+  }
+  sqlite3_mutex_enter(p->db->mutex);
+  rc = vdbeUnbind(p, i);
+  if( rc==SQLITE_OK && zData!=0 ){
+    pVar = &p->aVar[i-1];
+    rc = sqlite3VdbeMemSetStr(pVar, zData, nData, encoding, xDel);
+    if( rc==SQLITE_OK && encoding!=0 ){
+      rc = sqlite3VdbeChangeEncoding(pVar, ENC(p->db));
+    }
+    sqlite3Error(p->db, rc, 0);
+    rc = sqlite3ApiExit(p->db, rc);
+  }
+  sqlite3_mutex_leave(p->db->mutex);
+  return rc;
+}
+
+
+/*
+** Bind a blob value to an SQL statement variable.
+*/
+int sqlite3_bind_blob(
+  sqlite3_stmt *pStmt, 
+  int i, 
+  const void *zData, 
+  int nData, 
+  void (*xDel)(void*)
+){
+  return bindText(pStmt, i, zData, nData, xDel, 0);
+}
+int sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){
+  int rc;
+  Vdbe *p = (Vdbe *)pStmt;
+  sqlite3_mutex_enter(p->db->mutex);
+  rc = vdbeUnbind(p, i);
+  if( rc==SQLITE_OK ){
+    sqlite3VdbeMemSetDouble(&p->aVar[i-1], rValue);
+  }
+  sqlite3_mutex_leave(p->db->mutex);
+  return rc;
+}
+int sqlite3_bind_int(sqlite3_stmt *p, int i, int iValue){
+  return sqlite3_bind_int64(p, i, (i64)iValue);
+}
+int sqlite3_bind_int64(sqlite3_stmt *pStmt, int i, sqlite_int64 iValue){
+  int rc;
+  Vdbe *p = (Vdbe *)pStmt;
+  sqlite3_mutex_enter(p->db->mutex);
+  rc = vdbeUnbind(p, i);
+  if( rc==SQLITE_OK ){
+    sqlite3VdbeMemSetInt64(&p->aVar[i-1], iValue);
+  }
+  sqlite3_mutex_leave(p->db->mutex);
+  return rc;
+}
+int sqlite3_bind_null(sqlite3_stmt *pStmt, int i){
+  int rc;
+  Vdbe *p = (Vdbe*)pStmt;
+  sqlite3_mutex_enter(p->db->mutex);
+  rc = vdbeUnbind(p, i);
+  sqlite3_mutex_leave(p->db->mutex);
+  return rc;
+}
+int sqlite3_bind_text( 
+  sqlite3_stmt *pStmt, 
+  int i, 
+  const char *zData, 
+  int nData, 
+  void (*xDel)(void*)
+){
+  return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF8);
+}
+#ifndef SQLITE_OMIT_UTF16
+int sqlite3_bind_text16(
+  sqlite3_stmt *pStmt, 
+  int i, 
+  const void *zData, 
+  int nData, 
+  void (*xDel)(void*)
+){
+  return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF16NATIVE);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+int sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_value *pValue){
+  int rc;
+  Vdbe *p = (Vdbe *)pStmt;
+  sqlite3_mutex_enter(p->db->mutex);
+  rc = vdbeUnbind(p, i);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3VdbeMemCopy(&p->aVar[i-1], pValue);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3VdbeChangeEncoding(&p->aVar[i-1], ENC(p->db));
+    }
+  }
+  rc = sqlite3ApiExit(p->db, rc);
+  sqlite3_mutex_leave(p->db->mutex);
+  return rc;
+}
+int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
+  int rc;
+  Vdbe *p = (Vdbe *)pStmt;
+  sqlite3_mutex_enter(p->db->mutex);
+  rc = vdbeUnbind(p, i);
+  if( rc==SQLITE_OK ){
+    sqlite3VdbeMemSetZeroBlob(&p->aVar[i-1], n);
+  }
+  sqlite3_mutex_leave(p->db->mutex);
+  return rc;
+}
+
+/*
+** Return the number of wildcards that can be potentially bound to.
+** This routine is added to support DBD::SQLite.  
+*/
+int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
+  Vdbe *p = (Vdbe*)pStmt;
+  return p ? p->nVar : 0;
+}
+
+/*
+** Create a mapping from variable numbers to variable names
+** in the Vdbe.azVar[] array, if such a mapping does not already
+** exist.
+*/
+static void createVarMap(Vdbe *p){
+  if( !p->okVar ){
+    sqlite3_mutex_enter(p->db->mutex);
+    if( !p->okVar ){
+      int j;
+      Op *pOp;
+      for(j=0, pOp=p->aOp; j<p->nOp; j++, pOp++){
+        if( pOp->opcode==OP_Variable ){
+          assert( pOp->p1>0 && pOp->p1<=p->nVar );
+          p->azVar[pOp->p1-1] = pOp->p4.z;
+        }
+      }
+      p->okVar = 1;
+    }
+    sqlite3_mutex_leave(p->db->mutex);
+  }
+}
+
+/*
+** Return the name of a wildcard parameter.  Return NULL if the index
+** is out of range or if the wildcard is unnamed.
+**
+** The result is always UTF-8.
+*/
+const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
+  Vdbe *p = (Vdbe*)pStmt;
+  if( p==0 || i<1 || i>p->nVar ){
+    return 0;
+  }
+  createVarMap(p);
+  return p->azVar[i-1];
+}
+
+/*
+** Given a wildcard parameter name, return the index of the variable
+** with that name.  If there is no variable with the given name,
+** return 0.
+*/
+int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
+  Vdbe *p = (Vdbe*)pStmt;
+  int i;
+  if( p==0 ){
+    return 0;
+  }
+  createVarMap(p); 
+  if( zName ){
+    for(i=0; i<p->nVar; i++){
+      const char *z = p->azVar[i];
+      if( z && strcmp(z,zName)==0 ){
+        return i+1;
+      }
+    }
+  }
+  return 0;
+}
+
+/*
+** Transfer all bindings from the first statement over to the second.
+** If the two statements contain a different number of bindings, then
+** an SQLITE_ERROR is returned.
+*/
+int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
+  Vdbe *pFrom = (Vdbe*)pFromStmt;
+  Vdbe *pTo = (Vdbe*)pToStmt;
+  int i, rc = SQLITE_OK;
+  if( (pFrom->magic!=VDBE_MAGIC_RUN && pFrom->magic!=VDBE_MAGIC_HALT)
+    || (pTo->magic!=VDBE_MAGIC_RUN && pTo->magic!=VDBE_MAGIC_HALT)
+    || pTo->db!=pFrom->db ){
+    return SQLITE_MISUSE;
+  }
+  if( pFrom->nVar!=pTo->nVar ){
+    return SQLITE_ERROR;
+  }
+  sqlite3_mutex_enter(pTo->db->mutex);
+  for(i=0; rc==SQLITE_OK && i<pFrom->nVar; i++){
+    sqlite3VdbeMemMove(&pTo->aVar[i], &pFrom->aVar[i]);
+  }
+  sqlite3_mutex_leave(pTo->db->mutex);
+  assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
+  return rc;
+}
+
+/*
+** Return the sqlite3* database handle to which the prepared statement given
+** in the argument belongs.  This is the same database handle that was
+** the first argument to the sqlite3_prepare() that was used to create
+** the statement in the first place.
+*/
+sqlite3 *sqlite3_db_handle(sqlite3_stmt *pStmt){
+  return pStmt ? ((Vdbe*)pStmt)->db : 0;
+}
+
+/*
+** Return a pointer to the next prepared statement after pStmt associated
+** with database connection pDb.  If pStmt is NULL, return the first
+** prepared statement for the database connection.  Return NULL if there
+** are no more.
+*/
+sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
+  sqlite3_stmt *pNext;
+  sqlite3_mutex_enter(pDb->mutex);
+  if( pStmt==0 ){
+    pNext = (sqlite3_stmt*)pDb->pVdbe;
+  }else{
+    pNext = (sqlite3_stmt*)((Vdbe*)pStmt)->pNext;
+  }
+  sqlite3_mutex_leave(pDb->mutex);
+  return pNext;
+}
diff --git a/third_party/sqlite/src/vdbeaux.c b/third_party/sqlite/src/vdbeaux.c
new file mode 100755
index 0000000..cded81f
--- /dev/null
+++ b/third_party/sqlite/src/vdbeaux.c
@@ -0,0 +1,2498 @@
+/*
+** 2003 September 6
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code used for creating, destroying, and populating
+** a VDBE (or an "sqlite3_stmt" as it is known to the outside world.)  Prior
+** to version 2.8.7, all this code was combined into the vdbe.c source file.
+** But that file was getting too big so this subroutines were split out.
+**
+** $Id: vdbeaux.c,v 1.405 2008/08/02 03:50:39 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+#include "vdbeInt.h"
+
+
+
+/*
+** When debugging the code generator in a symbolic debugger, one can
+** set the sqlite3VdbeAddopTrace to 1 and all opcodes will be printed
+** as they are added to the instruction stream.
+*/
+#ifdef SQLITE_DEBUG
+int sqlite3VdbeAddopTrace = 0;
+#endif
+
+
+/*
+** Create a new virtual database engine.
+*/
+Vdbe *sqlite3VdbeCreate(sqlite3 *db){
+  Vdbe *p;
+  p = sqlite3DbMallocZero(db, sizeof(Vdbe) );
+  if( p==0 ) return 0;
+  p->db = db;
+  if( db->pVdbe ){
+    db->pVdbe->pPrev = p;
+  }
+  p->pNext = db->pVdbe;
+  p->pPrev = 0;
+  db->pVdbe = p;
+  p->magic = VDBE_MAGIC_INIT;
+  return p;
+}
+
+/*
+** Remember the SQL string for a prepared statement.
+*/
+void sqlite3VdbeSetSql(Vdbe *p, const char *z, int n){
+  if( p==0 ) return;
+  assert( p->zSql==0 );
+  p->zSql = sqlite3DbStrNDup(p->db, z, n);
+}
+
+/*
+** Return the SQL associated with a prepared statement
+*/
+const char *sqlite3_sql(sqlite3_stmt *pStmt){
+  return ((Vdbe *)pStmt)->zSql;
+}
+
+/*
+** Swap all content between two VDBE structures.
+*/
+void sqlite3VdbeSwap(Vdbe *pA, Vdbe *pB){
+  Vdbe tmp, *pTmp;
+  char *zTmp;
+  int nTmp;
+  tmp = *pA;
+  *pA = *pB;
+  *pB = tmp;
+  pTmp = pA->pNext;
+  pA->pNext = pB->pNext;
+  pB->pNext = pTmp;
+  pTmp = pA->pPrev;
+  pA->pPrev = pB->pPrev;
+  pB->pPrev = pTmp;
+  zTmp = pA->zSql;
+  pA->zSql = pB->zSql;
+  pB->zSql = zTmp;
+  nTmp = pA->nSql;
+  pA->nSql = pB->nSql;
+  pB->nSql = nTmp;
+}
+
+#ifdef SQLITE_DEBUG
+/*
+** Turn tracing on or off
+*/
+void sqlite3VdbeTrace(Vdbe *p, FILE *trace){
+  p->trace = trace;
+}
+#endif
+
+/*
+** Resize the Vdbe.aOp array so that it contains at least N
+** elements.
+**
+** If an out-of-memory error occurs while resizing the array,
+** Vdbe.aOp and Vdbe.nOpAlloc remain unchanged (this is so that
+** any opcodes already allocated can be correctly deallocated
+** along with the rest of the Vdbe).
+*/
+static void resizeOpArray(Vdbe *p, int N){
+  VdbeOp *pNew;
+  pNew = sqlite3DbRealloc(p->db, p->aOp, N*sizeof(Op));
+  if( pNew ){
+    p->nOpAlloc = N;
+    p->aOp = pNew;
+  }
+}
+
+/*
+** Add a new instruction to the list of instructions current in the
+** VDBE.  Return the address of the new instruction.
+**
+** Parameters:
+**
+**    p               Pointer to the VDBE
+**
+**    op              The opcode for this instruction
+**
+**    p1, p2, p3      Operands
+**
+** Use the sqlite3VdbeResolveLabel() function to fix an address and
+** the sqlite3VdbeChangeP4() function to change the value of the P4
+** operand.
+*/
+int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
+  int i;
+  VdbeOp *pOp;
+
+  i = p->nOp;
+  assert( p->magic==VDBE_MAGIC_INIT );
+  if( p->nOpAlloc<=i ){
+    resizeOpArray(p, p->nOpAlloc ? p->nOpAlloc*2 : 1024/sizeof(Op));
+    if( p->db->mallocFailed ){
+      return 0;
+    }
+  }
+  p->nOp++;
+  pOp = &p->aOp[i];
+  pOp->opcode = op;
+  pOp->p5 = 0;
+  pOp->p1 = p1;
+  pOp->p2 = p2;
+  pOp->p3 = p3;
+  pOp->p4.p = 0;
+  pOp->p4type = P4_NOTUSED;
+  p->expired = 0;
+#ifdef SQLITE_DEBUG
+  pOp->zComment = 0;
+  if( sqlite3VdbeAddopTrace ) sqlite3VdbePrintOp(0, i, &p->aOp[i]);
+#endif
+#ifdef VDBE_PROFILE
+  pOp->cycles = 0;
+  pOp->cnt = 0;
+#endif
+  return i;
+}
+int sqlite3VdbeAddOp0(Vdbe *p, int op){
+  return sqlite3VdbeAddOp3(p, op, 0, 0, 0);
+}
+int sqlite3VdbeAddOp1(Vdbe *p, int op, int p1){
+  return sqlite3VdbeAddOp3(p, op, p1, 0, 0);
+}
+int sqlite3VdbeAddOp2(Vdbe *p, int op, int p1, int p2){
+  return sqlite3VdbeAddOp3(p, op, p1, p2, 0);
+}
+
+
+/*
+** Add an opcode that includes the p4 value as a pointer.
+*/
+int sqlite3VdbeAddOp4(
+  Vdbe *p,            /* Add the opcode to this VM */
+  int op,             /* The new opcode */
+  int p1,             /* The P1 operand */
+  int p2,             /* The P2 operand */
+  int p3,             /* The P3 operand */
+  const char *zP4,    /* The P4 operand */
+  int p4type          /* P4 operand type */
+){
+  int addr = sqlite3VdbeAddOp3(p, op, p1, p2, p3);
+  sqlite3VdbeChangeP4(p, addr, zP4, p4type);
+  return addr;
+}
+
+/*
+** Create a new symbolic label for an instruction that has yet to be
+** coded.  The symbolic label is really just a negative number.  The
+** label can be used as the P2 value of an operation.  Later, when
+** the label is resolved to a specific address, the VDBE will scan
+** through its operation list and change all values of P2 which match
+** the label into the resolved address.
+**
+** The VDBE knows that a P2 value is a label because labels are
+** always negative and P2 values are suppose to be non-negative.
+** Hence, a negative P2 value is a label that has yet to be resolved.
+**
+** Zero is returned if a malloc() fails.
+*/
+int sqlite3VdbeMakeLabel(Vdbe *p){
+  int i;
+  i = p->nLabel++;
+  assert( p->magic==VDBE_MAGIC_INIT );
+  if( i>=p->nLabelAlloc ){
+    p->nLabelAlloc = p->nLabelAlloc*2 + 10;
+    p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel,
+                                    p->nLabelAlloc*sizeof(p->aLabel[0]));
+  }
+  if( p->aLabel ){
+    p->aLabel[i] = -1;
+  }
+  return -1-i;
+}
+
+/*
+** Resolve label "x" to be the address of the next instruction to
+** be inserted.  The parameter "x" must have been obtained from
+** a prior call to sqlite3VdbeMakeLabel().
+*/
+void sqlite3VdbeResolveLabel(Vdbe *p, int x){
+  int j = -1-x;
+  assert( p->magic==VDBE_MAGIC_INIT );
+  assert( j>=0 && j<p->nLabel );
+  if( p->aLabel ){
+    p->aLabel[j] = p->nOp;
+  }
+}
+
+/*
+** Loop through the program looking for P2 values that are negative
+** on jump instructions.  Each such value is a label.  Resolve the
+** label by setting the P2 value to its correct non-zero value.
+**
+** This routine is called once after all opcodes have been inserted.
+**
+** Variable *pMaxFuncArgs is set to the maximum value of any P2 argument 
+** to an OP_Function, OP_AggStep or OP_VFilter opcode. This is used by 
+** sqlite3VdbeMakeReady() to size the Vdbe.apArg[] array.
+**
+** This routine also does the following optimization:  It scans for
+** instructions that might cause a statement rollback.  Such instructions
+** are:
+**
+**   *  OP_Halt with P1=SQLITE_CONSTRAINT and P2=OE_Abort.
+**   *  OP_Destroy
+**   *  OP_VUpdate
+**   *  OP_VRename
+**
+** If no such instruction is found, then every Statement instruction 
+** is changed to a Noop.  In this way, we avoid creating the statement 
+** journal file unnecessarily.
+*/
+static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
+  int i;
+  int nMaxArgs = 0;
+  Op *pOp;
+  int *aLabel = p->aLabel;
+  int doesStatementRollback = 0;
+  int hasStatementBegin = 0;
+  for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
+    u8 opcode = pOp->opcode;
+
+    if( opcode==OP_Function || opcode==OP_AggStep ){
+      if( pOp->p5>nMaxArgs ) nMaxArgs = pOp->p5;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    }else if( opcode==OP_VUpdate ){
+      if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
+#endif
+    }
+    if( opcode==OP_Halt ){
+      if( pOp->p1==SQLITE_CONSTRAINT && pOp->p2==OE_Abort ){
+        doesStatementRollback = 1;
+      }
+    }else if( opcode==OP_Statement ){
+      hasStatementBegin = 1;
+    }else if( opcode==OP_Destroy ){
+      doesStatementRollback = 1;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    }else if( opcode==OP_VUpdate || opcode==OP_VRename ){
+      doesStatementRollback = 1;
+    }else if( opcode==OP_VFilter ){
+      int n;
+      assert( p->nOp - i >= 3 );
+      assert( pOp[-1].opcode==OP_Integer );
+      n = pOp[-1].p1;
+      if( n>nMaxArgs ) nMaxArgs = n;
+#endif
+    }
+
+    if( sqlite3VdbeOpcodeHasProperty(opcode, OPFLG_JUMP) && pOp->p2<0 ){
+      assert( -1-pOp->p2<p->nLabel );
+      pOp->p2 = aLabel[-1-pOp->p2];
+    }
+  }
+  sqlite3DbFree(p->db, p->aLabel);
+  p->aLabel = 0;
+
+  *pMaxFuncArgs = nMaxArgs;
+
+  /* If we never rollback a statement transaction, then statement
+  ** transactions are not needed.  So change every OP_Statement
+  ** opcode into an OP_Noop.  This avoid a call to sqlite3OsOpenExclusive()
+  ** which can be expensive on some platforms.
+  */
+  if( hasStatementBegin && !doesStatementRollback ){
+    for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
+      if( pOp->opcode==OP_Statement ){
+        pOp->opcode = OP_Noop;
+      }
+    }
+  }
+}
+
+/*
+** Return the address of the next instruction to be inserted.
+*/
+int sqlite3VdbeCurrentAddr(Vdbe *p){
+  assert( p->magic==VDBE_MAGIC_INIT );
+  return p->nOp;
+}
+
+/*
+** Add a whole list of operations to the operation stack.  Return the
+** address of the first operation added.
+*/
+int sqlite3VdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp){
+  int addr;
+  assert( p->magic==VDBE_MAGIC_INIT );
+  if( p->nOp + nOp > p->nOpAlloc ){
+    resizeOpArray(p, p->nOpAlloc ? p->nOpAlloc*2 : 1024/sizeof(Op));
+    assert( p->nOp+nOp<=p->nOpAlloc || p->db->mallocFailed );
+  }
+  if( p->db->mallocFailed ){
+    return 0;
+  }
+  addr = p->nOp;
+  if( nOp>0 ){
+    int i;
+    VdbeOpList const *pIn = aOp;
+    for(i=0; i<nOp; i++, pIn++){
+      int p2 = pIn->p2;
+      VdbeOp *pOut = &p->aOp[i+addr];
+      pOut->opcode = pIn->opcode;
+      pOut->p1 = pIn->p1;
+      if( p2<0 && sqlite3VdbeOpcodeHasProperty(pOut->opcode, OPFLG_JUMP) ){
+        pOut->p2 = addr + ADDR(p2);
+      }else{
+        pOut->p2 = p2;
+      }
+      pOut->p3 = pIn->p3;
+      pOut->p4type = P4_NOTUSED;
+      pOut->p4.p = 0;
+      pOut->p5 = 0;
+#ifdef SQLITE_DEBUG
+      pOut->zComment = 0;
+      if( sqlite3VdbeAddopTrace ){
+        sqlite3VdbePrintOp(0, i+addr, &p->aOp[i+addr]);
+      }
+#endif
+    }
+    p->nOp += nOp;
+  }
+  return addr;
+}
+
+/*
+** Change the value of the P1 operand for a specific instruction.
+** This routine is useful when a large program is loaded from a
+** static array using sqlite3VdbeAddOpList but we want to make a
+** few minor changes to the program.
+*/
+void sqlite3VdbeChangeP1(Vdbe *p, int addr, int val){
+  assert( p==0 || p->magic==VDBE_MAGIC_INIT );
+  if( p && addr>=0 && p->nOp>addr && p->aOp ){
+    p->aOp[addr].p1 = val;
+  }
+}
+
+/*
+** Change the value of the P2 operand for a specific instruction.
+** This routine is useful for setting a jump destination.
+*/
+void sqlite3VdbeChangeP2(Vdbe *p, int addr, int val){
+  assert( p==0 || p->magic==VDBE_MAGIC_INIT );
+  if( p && addr>=0 && p->nOp>addr && p->aOp ){
+    p->aOp[addr].p2 = val;
+  }
+}
+
+/*
+** Change the value of the P3 operand for a specific instruction.
+*/
+void sqlite3VdbeChangeP3(Vdbe *p, int addr, int val){
+  assert( p==0 || p->magic==VDBE_MAGIC_INIT );
+  if( p && addr>=0 && p->nOp>addr && p->aOp ){
+    p->aOp[addr].p3 = val;
+  }
+}
+
+/*
+** Change the value of the P5 operand for the most recently
+** added operation.
+*/
+void sqlite3VdbeChangeP5(Vdbe *p, u8 val){
+  assert( p==0 || p->magic==VDBE_MAGIC_INIT );
+  if( p && p->aOp ){
+    assert( p->nOp>0 );
+    p->aOp[p->nOp-1].p5 = val;
+  }
+}
+
+/*
+** Change the P2 operand of instruction addr so that it points to
+** the address of the next instruction to be coded.
+*/
+void sqlite3VdbeJumpHere(Vdbe *p, int addr){
+  sqlite3VdbeChangeP2(p, addr, p->nOp);
+}
+
+
+/*
+** If the input FuncDef structure is ephemeral, then free it.  If
+** the FuncDef is not ephermal, then do nothing.
+*/
+static void freeEphemeralFunction(sqlite3 *db, FuncDef *pDef){
+  if( pDef && (pDef->flags & SQLITE_FUNC_EPHEM)!=0 ){
+    sqlite3DbFree(db, pDef);
+  }
+}
+
+/*
+** Delete a P4 value if necessary.
+*/
+static void freeP4(sqlite3 *db, int p4type, void *p4){
+  if( p4 ){
+    switch( p4type ){
+      case P4_REAL:
+      case P4_INT64:
+      case P4_MPRINTF:
+      case P4_DYNAMIC:
+      case P4_KEYINFO:
+      case P4_INTARRAY:
+      case P4_KEYINFO_HANDOFF: {
+        sqlite3DbFree(db, p4);
+        break;
+      }
+      case P4_VDBEFUNC: {
+        VdbeFunc *pVdbeFunc = (VdbeFunc *)p4;
+        freeEphemeralFunction(db, pVdbeFunc->pFunc);
+        sqlite3VdbeDeleteAuxData(pVdbeFunc, 0);
+        sqlite3DbFree(db, pVdbeFunc);
+        break;
+      }
+      case P4_FUNCDEF: {
+        freeEphemeralFunction(db, (FuncDef*)p4);
+        break;
+      }
+      case P4_MEM: {
+        sqlite3ValueFree((sqlite3_value*)p4);
+        break;
+      }
+    }
+  }
+}
+
+
+/*
+** Change N opcodes starting at addr to No-ops.
+*/
+void sqlite3VdbeChangeToNoop(Vdbe *p, int addr, int N){
+  if( p && p->aOp ){
+    VdbeOp *pOp = &p->aOp[addr];
+    sqlite3 *db = p->db;
+    while( N-- ){
+      freeP4(db, pOp->p4type, pOp->p4.p);
+      memset(pOp, 0, sizeof(pOp[0]));
+      pOp->opcode = OP_Noop;
+      pOp++;
+    }
+  }
+}
+
+/*
+** Change the value of the P4 operand for a specific instruction.
+** This routine is useful when a large program is loaded from a
+** static array using sqlite3VdbeAddOpList but we want to make a
+** few minor changes to the program.
+**
+** If n>=0 then the P4 operand is dynamic, meaning that a copy of
+** the string is made into memory obtained from sqlite3_malloc().
+** A value of n==0 means copy bytes of zP4 up to and including the
+** first null byte.  If n>0 then copy n+1 bytes of zP4.
+**
+** If n==P4_KEYINFO it means that zP4 is a pointer to a KeyInfo structure.
+** A copy is made of the KeyInfo structure into memory obtained from
+** sqlite3_malloc, to be freed when the Vdbe is finalized.
+** n==P4_KEYINFO_HANDOFF indicates that zP4 points to a KeyInfo structure
+** stored in memory that the caller has obtained from sqlite3_malloc. The 
+** caller should not free the allocation, it will be freed when the Vdbe is
+** finalized.
+** 
+** Other values of n (P4_STATIC, P4_COLLSEQ etc.) indicate that zP4 points
+** to a string or structure that is guaranteed to exist for the lifetime of
+** the Vdbe. In these cases we can just copy the pointer.
+**
+** If addr<0 then change P4 on the most recently inserted instruction.
+*/
+void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
+  Op *pOp;
+  sqlite3 *db;
+  assert( p!=0 );
+  db = p->db;
+  assert( p->magic==VDBE_MAGIC_INIT );
+  if( p->aOp==0 || db->mallocFailed ){
+    if (n != P4_KEYINFO) {
+      freeP4(db, n, (void*)*(char**)&zP4);
+    }
+    return;
+  }
+  assert( addr<p->nOp );
+  if( addr<0 ){
+    addr = p->nOp - 1;
+    if( addr<0 ) return;
+  }
+  pOp = &p->aOp[addr];
+  freeP4(db, pOp->p4type, pOp->p4.p);
+  pOp->p4.p = 0;
+  if( n==P4_INT32 ){
+    /* Note: this cast is safe, because the origin data point was an int
+    ** that was cast to a (const char *). */
+    pOp->p4.i = SQLITE_PTR_TO_INT(zP4);
+    pOp->p4type = n;
+  }else if( zP4==0 ){
+    pOp->p4.p = 0;
+    pOp->p4type = P4_NOTUSED;
+  }else if( n==P4_KEYINFO ){
+    KeyInfo *pKeyInfo;
+    int nField, nByte;
+
+    nField = ((KeyInfo*)zP4)->nField;
+    nByte = sizeof(*pKeyInfo) + (nField-1)*sizeof(pKeyInfo->aColl[0]) + nField;
+    pKeyInfo = sqlite3Malloc( nByte );
+    pOp->p4.pKeyInfo = pKeyInfo;
+    if( pKeyInfo ){
+      u8 *aSortOrder;
+      memcpy(pKeyInfo, zP4, nByte);
+      aSortOrder = pKeyInfo->aSortOrder;
+      if( aSortOrder ){
+        pKeyInfo->aSortOrder = (unsigned char*)&pKeyInfo->aColl[nField];
+        memcpy(pKeyInfo->aSortOrder, aSortOrder, nField);
+      }
+      pOp->p4type = P4_KEYINFO;
+    }else{
+      p->db->mallocFailed = 1;
+      pOp->p4type = P4_NOTUSED;
+    }
+  }else if( n==P4_KEYINFO_HANDOFF ){
+    pOp->p4.p = (void*)zP4;
+    pOp->p4type = P4_KEYINFO;
+  }else if( n<0 ){
+    pOp->p4.p = (void*)zP4;
+    pOp->p4type = n;
+  }else{
+    if( n==0 ) n = strlen(zP4);
+    pOp->p4.z = sqlite3DbStrNDup(p->db, zP4, n);
+    pOp->p4type = P4_DYNAMIC;
+  }
+}
+
+#ifndef NDEBUG
+/*
+** Change the comment on the the most recently coded instruction.  Or
+** insert a No-op and add the comment to that new instruction.  This
+** makes the code easier to read during debugging.  None of this happens
+** in a production build.
+*/
+void sqlite3VdbeComment(Vdbe *p, const char *zFormat, ...){
+  va_list ap;
+  assert( p->nOp>0 || p->aOp==0 );
+  assert( p->aOp==0 || p->aOp[p->nOp-1].zComment==0 || p->db->mallocFailed );
+  if( p->nOp ){
+    char **pz = &p->aOp[p->nOp-1].zComment;
+    va_start(ap, zFormat);
+    sqlite3DbFree(p->db, *pz);
+    *pz = sqlite3VMPrintf(p->db, zFormat, ap);
+    va_end(ap);
+  }
+}
+void sqlite3VdbeNoopComment(Vdbe *p, const char *zFormat, ...){
+  va_list ap;
+  sqlite3VdbeAddOp0(p, OP_Noop);
+  assert( p->nOp>0 || p->aOp==0 );
+  assert( p->aOp==0 || p->aOp[p->nOp-1].zComment==0 || p->db->mallocFailed );
+  if( p->nOp ){
+    char **pz = &p->aOp[p->nOp-1].zComment;
+    va_start(ap, zFormat);
+    sqlite3DbFree(p->db, *pz);
+    *pz = sqlite3VMPrintf(p->db, zFormat, ap);
+    va_end(ap);
+  }
+}
+#endif  /* NDEBUG */
+
+/*
+** Return the opcode for a given address.
+*/
+VdbeOp *sqlite3VdbeGetOp(Vdbe *p, int addr){
+  assert( p->magic==VDBE_MAGIC_INIT );
+  assert( (addr>=0 && addr<p->nOp) || p->db->mallocFailed );
+  return ((addr>=0 && addr<p->nOp)?(&p->aOp[addr]):0);
+}
+
+#if !defined(SQLITE_OMIT_EXPLAIN) || !defined(NDEBUG) \
+     || defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
+/*
+** Compute a string that describes the P4 parameter for an opcode.
+** Use zTemp for any required temporary buffer space.
+*/
+static char *displayP4(Op *pOp, char *zTemp, int nTemp){
+  char *zP4 = zTemp;
+  assert( nTemp>=20 );
+  switch( pOp->p4type ){
+    case P4_KEYINFO_STATIC:
+    case P4_KEYINFO: {
+      int i, j;
+      KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
+      sqlite3_snprintf(nTemp, zTemp, "keyinfo(%d", pKeyInfo->nField);
+      i = strlen(zTemp);
+      for(j=0; j<pKeyInfo->nField; j++){
+        CollSeq *pColl = pKeyInfo->aColl[j];
+        if( pColl ){
+          int n = strlen(pColl->zName);
+          if( i+n>nTemp-6 ){
+            memcpy(&zTemp[i],",...",4);
+            break;
+          }
+          zTemp[i++] = ',';
+          if( pKeyInfo->aSortOrder && pKeyInfo->aSortOrder[j] ){
+            zTemp[i++] = '-';
+          }
+          memcpy(&zTemp[i], pColl->zName,n+1);
+          i += n;
+        }else if( i+4<nTemp-6 ){
+          memcpy(&zTemp[i],",nil",4);
+          i += 4;
+        }
+      }
+      zTemp[i++] = ')';
+      zTemp[i] = 0;
+      assert( i<nTemp );
+      break;
+    }
+    case P4_COLLSEQ: {
+      CollSeq *pColl = pOp->p4.pColl;
+      sqlite3_snprintf(nTemp, zTemp, "collseq(%.20s)", pColl->zName);
+      break;
+    }
+    case P4_FUNCDEF: {
+      FuncDef *pDef = pOp->p4.pFunc;
+      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
+      break;
+    }
+    case P4_INT64: {
+      sqlite3_snprintf(nTemp, zTemp, "%lld", *pOp->p4.pI64);
+      break;
+    }
+    case P4_INT32: {
+      sqlite3_snprintf(nTemp, zTemp, "%d", pOp->p4.i);
+      break;
+    }
+    case P4_REAL: {
+      sqlite3_snprintf(nTemp, zTemp, "%.16g", *pOp->p4.pReal);
+      break;
+    }
+    case P4_MEM: {
+      Mem *pMem = pOp->p4.pMem;
+      assert( (pMem->flags & MEM_Null)==0 );
+      if( pMem->flags & MEM_Str ){
+        zP4 = pMem->z;
+      }else if( pMem->flags & MEM_Int ){
+        sqlite3_snprintf(nTemp, zTemp, "%lld", pMem->u.i);
+      }else if( pMem->flags & MEM_Real ){
+        sqlite3_snprintf(nTemp, zTemp, "%.16g", pMem->r);
+      }
+      break;
+    }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    case P4_VTAB: {
+      sqlite3_vtab *pVtab = pOp->p4.pVtab;
+      sqlite3_snprintf(nTemp, zTemp, "vtab:%p:%p", pVtab, pVtab->pModule);
+      break;
+    }
+#endif
+    case P4_INTARRAY: {
+      sqlite3_snprintf(nTemp, zTemp, "intarray");
+      break;
+    }
+    default: {
+      zP4 = pOp->p4.z;
+      if( zP4==0 ){
+        zP4 = zTemp;
+        zTemp[0] = 0;
+      }
+    }
+  }
+  assert( zP4!=0 );
+  return zP4;
+}
+#endif
+
+/*
+** Declare to the Vdbe that the BTree object at db->aDb[i] is used.
+**
+*/
+void sqlite3VdbeUsesBtree(Vdbe *p, int i){
+  int mask;
+  assert( i>=0 && i<p->db->nDb );
+  assert( i<sizeof(p->btreeMask)*8 );
+  mask = 1<<i;
+  if( (p->btreeMask & mask)==0 ){
+    p->btreeMask |= mask;
+    sqlite3BtreeMutexArrayInsert(&p->aMutex, p->db->aDb[i].pBt);
+  }
+}
+
+
+#if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
+/*
+** Print a single opcode.  This routine is used for debugging only.
+*/
+void sqlite3VdbePrintOp(FILE *pOut, int pc, Op *pOp){
+  char *zP4;
+  char zPtr[50];
+  static const char *zFormat1 = "%4d %-13s %4d %4d %4d %-4s %.2X %s\n";
+  if( pOut==0 ) pOut = stdout;
+  zP4 = displayP4(pOp, zPtr, sizeof(zPtr));
+  fprintf(pOut, zFormat1, pc, 
+      sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5,
+#ifdef SQLITE_DEBUG
+      pOp->zComment ? pOp->zComment : ""
+#else
+      ""
+#endif
+  );
+  fflush(pOut);
+}
+#endif
+
+/*
+** Release an array of N Mem elements
+*/
+static void releaseMemArray(Mem *p, int N){
+  if( p && N ){
+    sqlite3 *db = p->db;
+    int malloc_failed = db->mallocFailed;
+    while( N-->0 ){
+      assert( N<2 || p[0].db==p[1].db );
+      sqlite3VdbeMemRelease(p);
+      p->flags = MEM_Null;
+      p++;
+    }
+    db->mallocFailed = malloc_failed;
+  }
+}
+
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+int sqlite3VdbeReleaseBuffers(Vdbe *p){
+  int ii;
+  int nFree = 0;
+  assert( sqlite3_mutex_held(p->db->mutex) );
+  for(ii=1; ii<=p->nMem; ii++){
+    Mem *pMem = &p->aMem[ii];
+    if( pMem->z && pMem->flags&MEM_Dyn ){
+      assert( !pMem->xDel );
+      nFree += sqlite3DbMallocSize(pMem->db, pMem->z);
+      sqlite3VdbeMemRelease(pMem);
+    }
+  }
+  return nFree;
+}
+#endif
+
+#ifndef SQLITE_OMIT_EXPLAIN
+/*
+** Give a listing of the program in the virtual machine.
+**
+** The interface is the same as sqlite3VdbeExec().  But instead of
+** running the code, it invokes the callback once for each instruction.
+** This feature is used to implement "EXPLAIN".
+**
+** When p->explain==1, each instruction is listed.  When
+** p->explain==2, only OP_Explain instructions are listed and these
+** are shown in a different format.  p->explain==2 is used to implement
+** EXPLAIN QUERY PLAN.
+*/
+int sqlite3VdbeList(
+  Vdbe *p                   /* The VDBE */
+){
+  sqlite3 *db = p->db;
+  int i;
+  int rc = SQLITE_OK;
+  Mem *pMem = p->pResultSet = &p->aMem[1];
+
+  assert( p->explain );
+  if( p->magic!=VDBE_MAGIC_RUN ) return SQLITE_MISUSE;
+  assert( db->magic==SQLITE_MAGIC_BUSY );
+  assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY );
+
+  /* Even though this opcode does not use dynamic strings for
+  ** the result, result columns may become dynamic if the user calls
+  ** sqlite3_column_text16(), causing a translation to UTF-16 encoding.
+  */
+  releaseMemArray(pMem, p->nMem);
+
+  do{
+    i = p->pc++;
+  }while( i<p->nOp && p->explain==2 && p->aOp[i].opcode!=OP_Explain );
+  if( i>=p->nOp ){
+    p->rc = SQLITE_OK;
+    rc = SQLITE_DONE;
+  }else if( db->u1.isInterrupted ){
+    p->rc = SQLITE_INTERRUPT;
+    rc = SQLITE_ERROR;
+    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3ErrStr(p->rc));
+  }else{
+    char *z;
+    Op *pOp = &p->aOp[i];
+    if( p->explain==1 ){
+      pMem->flags = MEM_Int;
+      pMem->type = SQLITE_INTEGER;
+      pMem->u.i = i;                                /* Program counter */
+      pMem++;
+  
+      pMem->flags = MEM_Static|MEM_Str|MEM_Term;
+      pMem->z = (char*)sqlite3OpcodeName(pOp->opcode);  /* Opcode */
+      assert( pMem->z!=0 );
+      pMem->n = strlen(pMem->z);
+      pMem->type = SQLITE_TEXT;
+      pMem->enc = SQLITE_UTF8;
+      pMem++;
+    }
+
+    pMem->flags = MEM_Int;
+    pMem->u.i = pOp->p1;                          /* P1 */
+    pMem->type = SQLITE_INTEGER;
+    pMem++;
+
+    pMem->flags = MEM_Int;
+    pMem->u.i = pOp->p2;                          /* P2 */
+    pMem->type = SQLITE_INTEGER;
+    pMem++;
+
+    if( p->explain==1 ){
+      pMem->flags = MEM_Int;
+      pMem->u.i = pOp->p3;                          /* P3 */
+      pMem->type = SQLITE_INTEGER;
+      pMem++;
+    }
+
+    if( sqlite3VdbeMemGrow(pMem, 32, 0) ){            /* P4 */
+      p->db->mallocFailed = 1;
+      return SQLITE_NOMEM;
+    }
+    pMem->flags = MEM_Dyn|MEM_Str|MEM_Term;
+    z = displayP4(pOp, pMem->z, 32);
+    if( z!=pMem->z ){
+      sqlite3VdbeMemSetStr(pMem, z, -1, SQLITE_UTF8, 0);
+    }else{
+      assert( pMem->z!=0 );
+      pMem->n = strlen(pMem->z);
+      pMem->enc = SQLITE_UTF8;
+    }
+    pMem->type = SQLITE_TEXT;
+    pMem++;
+
+    if( p->explain==1 ){
+      if( sqlite3VdbeMemGrow(pMem, 4, 0) ){
+        p->db->mallocFailed = 1;
+        return SQLITE_NOMEM;
+      }
+      pMem->flags = MEM_Dyn|MEM_Str|MEM_Term;
+      pMem->n = 2;
+      sqlite3_snprintf(3, pMem->z, "%.2x", pOp->p5);   /* P5 */
+      pMem->type = SQLITE_TEXT;
+      pMem->enc = SQLITE_UTF8;
+      pMem++;
+  
+#ifdef SQLITE_DEBUG
+      if( pOp->zComment ){
+        pMem->flags = MEM_Str|MEM_Term;
+        pMem->z = pOp->zComment;
+        pMem->n = strlen(pMem->z);
+        pMem->enc = SQLITE_UTF8;
+      }else
+#endif
+      {
+        pMem->flags = MEM_Null;                       /* Comment */
+        pMem->type = SQLITE_NULL;
+      }
+    }
+
+    p->nResColumn = 8 - 5*(p->explain-1);
+    p->rc = SQLITE_OK;
+    rc = SQLITE_ROW;
+  }
+  return rc;
+}
+#endif /* SQLITE_OMIT_EXPLAIN */
+
+#ifdef SQLITE_DEBUG
+/*
+** Print the SQL that was used to generate a VDBE program.
+*/
+void sqlite3VdbePrintSql(Vdbe *p){
+  int nOp = p->nOp;
+  VdbeOp *pOp;
+  if( nOp<1 ) return;
+  pOp = &p->aOp[0];
+  if( pOp->opcode==OP_Trace && pOp->p4.z!=0 ){
+    const char *z = pOp->p4.z;
+    while( isspace(*(u8*)z) ) z++;
+    printf("SQL: [%s]\n", z);
+  }
+}
+#endif
+
+#if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
+/*
+** Print an IOTRACE message showing SQL content.
+*/
+void sqlite3VdbeIOTraceSql(Vdbe *p){
+  int nOp = p->nOp;
+  VdbeOp *pOp;
+  if( sqlite3IoTrace==0 ) return;
+  if( nOp<1 ) return;
+  pOp = &p->aOp[0];
+  if( pOp->opcode==OP_Trace && pOp->p4.z!=0 ){
+    int i, j;
+    char z[1000];
+    sqlite3_snprintf(sizeof(z), z, "%s", pOp->p4.z);
+    for(i=0; isspace((unsigned char)z[i]); i++){}
+    for(j=0; z[i]; i++){
+      if( isspace((unsigned char)z[i]) ){
+        if( z[i-1]!=' ' ){
+          z[j++] = ' ';
+        }
+      }else{
+        z[j++] = z[i];
+      }
+    }
+    z[j] = 0;
+    sqlite3IoTrace("SQL %s\n", z);
+  }
+}
+#endif /* !SQLITE_OMIT_TRACE && SQLITE_ENABLE_IOTRACE */
+
+
+/*
+** Prepare a virtual machine for execution.  This involves things such
+** as allocating stack space and initializing the program counter.
+** After the VDBE has be prepped, it can be executed by one or more
+** calls to sqlite3VdbeExec().  
+**
+** This is the only way to move a VDBE from VDBE_MAGIC_INIT to
+** VDBE_MAGIC_RUN.
+*/
+void sqlite3VdbeMakeReady(
+  Vdbe *p,                       /* The VDBE */
+  int nVar,                      /* Number of '?' see in the SQL statement */
+  int nMem,                      /* Number of memory cells to allocate */
+  int nCursor,                   /* Number of cursors to allocate */
+  int isExplain                  /* True if the EXPLAIN keywords is present */
+){
+  int n;
+  sqlite3 *db = p->db;
+
+  assert( p!=0 );
+  assert( p->magic==VDBE_MAGIC_INIT );
+
+  /* There should be at least one opcode.
+  */
+  assert( p->nOp>0 );
+
+  /* Set the magic to VDBE_MAGIC_RUN sooner rather than later. This
+   * is because the call to resizeOpArray() below may shrink the
+   * p->aOp[] array to save memory if called when in VDBE_MAGIC_RUN 
+   * state.
+   */
+  p->magic = VDBE_MAGIC_RUN;
+
+  /* For each cursor required, also allocate a memory cell. Memory
+  ** cells (nMem+1-nCursor)..nMem, inclusive, will never be used by
+  ** the vdbe program. Instead they are used to allocate space for
+  ** Cursor/BtCursor structures. The blob of memory associated with 
+  ** cursor 0 is stored in memory cell nMem. Memory cell (nMem-1)
+  ** stores the blob of memory associated with cursor 1, etc.
+  **
+  ** See also: allocateCursor().
+  */
+  nMem += nCursor;
+
+  /*
+  ** Allocation space for registers.
+  */
+  if( p->aMem==0 ){
+    int nArg;       /* Maximum number of args passed to a user function. */
+    resolveP2Values(p, &nArg);
+    /*resizeOpArray(p, p->nOp);*/
+    assert( nVar>=0 );
+    if( isExplain && nMem<10 ){
+      p->nMem = nMem = 10;
+    }
+    p->aMem = sqlite3DbMallocZero(db,
+        nMem*sizeof(Mem)               /* aMem */
+      + nVar*sizeof(Mem)               /* aVar */
+      + nArg*sizeof(Mem*)              /* apArg */
+      + nVar*sizeof(char*)             /* azVar */
+      + nCursor*sizeof(Cursor*) + 1    /* apCsr */
+    );
+    if( !db->mallocFailed ){
+      p->aMem--;             /* aMem[] goes from 1..nMem */
+      p->nMem = nMem;        /*       not from 0..nMem-1 */
+      p->aVar = &p->aMem[nMem+1];
+      p->nVar = nVar;
+      p->okVar = 0;
+      p->apArg = (Mem**)&p->aVar[nVar];
+      p->azVar = (char**)&p->apArg[nArg];
+      p->apCsr = (Cursor**)&p->azVar[nVar];
+      p->nCursor = nCursor;
+      for(n=0; n<nVar; n++){
+        p->aVar[n].flags = MEM_Null;
+        p->aVar[n].db = db;
+      }
+      for(n=1; n<=nMem; n++){
+        p->aMem[n].flags = MEM_Null;
+        p->aMem[n].db = db;
+      }
+    }
+  }
+#ifdef SQLITE_DEBUG
+  for(n=1; n<p->nMem; n++){
+    assert( p->aMem[n].db==db );
+  }
+#endif
+
+  p->pc = -1;
+  p->rc = SQLITE_OK;
+  p->uniqueCnt = 0;
+  p->errorAction = OE_Abort;
+  p->explain |= isExplain;
+  p->magic = VDBE_MAGIC_RUN;
+  p->nChange = 0;
+  p->cacheCtr = 1;
+  p->minWriteFileFormat = 255;
+  p->openedStatement = 0;
+#ifdef VDBE_PROFILE
+  {
+    int i;
+    for(i=0; i<p->nOp; i++){
+      p->aOp[i].cnt = 0;
+      p->aOp[i].cycles = 0;
+    }
+  }
+#endif
+}
+
+/*
+** Close a VDBE cursor and release all the resources that cursor 
+** happens to hold.
+*/
+void sqlite3VdbeFreeCursor(Vdbe *p, Cursor *pCx){
+  if( pCx==0 ){
+    return;
+  }
+  if( pCx->pBt ){
+    sqlite3BtreeClose(pCx->pBt);
+    /* The pCx->pCursor will be close automatically, if it exists, by
+    ** the call above. */
+  }else if( pCx->pCursor ){
+    sqlite3BtreeCloseCursor(pCx->pCursor);
+  }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if( pCx->pVtabCursor ){
+    sqlite3_vtab_cursor *pVtabCursor = pCx->pVtabCursor;
+    const sqlite3_module *pModule = pCx->pModule;
+    p->inVtabMethod = 1;
+    (void)sqlite3SafetyOff(p->db);
+    pModule->xClose(pVtabCursor);
+    (void)sqlite3SafetyOn(p->db);
+    p->inVtabMethod = 0;
+  }
+#endif
+  if( !pCx->ephemPseudoTable ){
+    sqlite3DbFree(p->db, pCx->pData);
+  }
+}
+
+/*
+** Close all cursors except for VTab cursors that are currently
+** in use.
+*/
+static void closeAllCursorsExceptActiveVtabs(Vdbe *p){
+  int i;
+  if( p->apCsr==0 ) return;
+  for(i=0; i<p->nCursor; i++){
+    Cursor *pC = p->apCsr[i];
+    if( pC && (!p->inVtabMethod || !pC->pVtabCursor) ){
+      sqlite3VdbeFreeCursor(p, pC);
+      p->apCsr[i] = 0;
+    }
+  }
+}
+
+/*
+** Clean up the VM after execution.
+**
+** This routine will automatically close any cursors, lists, and/or
+** sorters that were left open.  It also deletes the values of
+** variables in the aVar[] array.
+*/
+static void Cleanup(Vdbe *p){
+  int i;
+  sqlite3 *db = p->db;
+  closeAllCursorsExceptActiveVtabs(p);
+  for(i=1; i<=p->nMem; i++){
+    MemSetTypeFlag(&p->aMem[i], MEM_Null);
+  }
+  releaseMemArray(&p->aMem[1], p->nMem);
+  sqlite3VdbeFifoClear(&p->sFifo);
+  if( p->contextStack ){
+    for(i=0; i<p->contextStackTop; i++){
+      sqlite3VdbeFifoClear(&p->contextStack[i].sFifo);
+    }
+    sqlite3DbFree(db, p->contextStack);
+  }
+  p->contextStack = 0;
+  p->contextStackDepth = 0;
+  p->contextStackTop = 0;
+  sqlite3DbFree(db, p->zErrMsg);
+  p->zErrMsg = 0;
+  p->pResultSet = 0;
+}
+
+/*
+** Set the number of result columns that will be returned by this SQL
+** statement. This is now set at compile time, rather than during
+** execution of the vdbe program so that sqlite3_column_count() can
+** be called on an SQL statement before sqlite3_step().
+*/
+void sqlite3VdbeSetNumCols(Vdbe *p, int nResColumn){
+  Mem *pColName;
+  int n;
+  sqlite3 *db = p->db;
+
+  releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
+  sqlite3DbFree(db, p->aColName);
+  n = nResColumn*COLNAME_N;
+  p->nResColumn = nResColumn;
+  p->aColName = pColName = (Mem*)sqlite3DbMallocZero(db, sizeof(Mem)*n );
+  if( p->aColName==0 ) return;
+  while( n-- > 0 ){
+    pColName->flags = MEM_Null;
+    pColName->db = p->db;
+    pColName++;
+  }
+}
+
+/*
+** Set the name of the idx'th column to be returned by the SQL statement.
+** zName must be a pointer to a nul terminated string.
+**
+** This call must be made after a call to sqlite3VdbeSetNumCols().
+**
+** If N==P4_STATIC  it means that zName is a pointer to a constant static
+** string and we can just copy the pointer. If it is P4_DYNAMIC, then 
+** the string is freed using sqlite3DbFree(db, ) when the vdbe is finished with
+** it. Otherwise, N bytes of zName are copied.
+*/
+int sqlite3VdbeSetColName(Vdbe *p, int idx, int var, const char *zName, int N){
+  int rc;
+  Mem *pColName;
+  assert( idx<p->nResColumn );
+  assert( var<COLNAME_N );
+  if( p->db->mallocFailed ) return SQLITE_NOMEM;
+  assert( p->aColName!=0 );
+  pColName = &(p->aColName[idx+var*p->nResColumn]);
+  if( N==P4_DYNAMIC || N==P4_STATIC ){
+    rc = sqlite3VdbeMemSetStr(pColName, zName, -1, SQLITE_UTF8, SQLITE_STATIC);
+  }else{
+    rc = sqlite3VdbeMemSetStr(pColName, zName, N, SQLITE_UTF8,SQLITE_TRANSIENT);
+  }
+  if( rc==SQLITE_OK && N==P4_DYNAMIC ){
+    pColName->flags &= (~MEM_Static);
+    pColName->zMalloc = pColName->z;
+  }
+  return rc;
+}
+
+/*
+** A read or write transaction may or may not be active on database handle
+** db. If a transaction is active, commit it. If there is a
+** write-transaction spanning more than one database file, this routine
+** takes care of the master journal trickery.
+*/
+static int vdbeCommit(sqlite3 *db, Vdbe *p){
+  int i;
+  int nTrans = 0;  /* Number of databases with an active write-transaction */
+  int rc = SQLITE_OK;
+  int needXcommit = 0;
+
+  /* Before doing anything else, call the xSync() callback for any
+  ** virtual module tables written in this transaction. This has to
+  ** be done before determining whether a master journal file is 
+  ** required, as an xSync() callback may add an attached database
+  ** to the transaction.
+  */
+  rc = sqlite3VtabSync(db, &p->zErrMsg);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  /* This loop determines (a) if the commit hook should be invoked and
+  ** (b) how many database files have open write transactions, not 
+  ** including the temp database. (b) is important because if more than 
+  ** one database file has an open write transaction, a master journal
+  ** file is required for an atomic commit.
+  */ 
+  for(i=0; i<db->nDb; i++){ 
+    Btree *pBt = db->aDb[i].pBt;
+    if( sqlite3BtreeIsInTrans(pBt) ){
+      needXcommit = 1;
+      if( i!=1 ) nTrans++;
+    }
+  }
+
+  /* If there are any write-transactions at all, invoke the commit hook */
+  if( needXcommit && db->xCommitCallback ){
+    (void)sqlite3SafetyOff(db);
+    rc = db->xCommitCallback(db->pCommitArg);
+    (void)sqlite3SafetyOn(db);
+    if( rc ){
+      return SQLITE_CONSTRAINT;
+    }
+  }
+
+  /* The simple case - no more than one database file (not counting the
+  ** TEMP database) has a transaction active.   There is no need for the
+  ** master-journal.
+  **
+  ** If the return value of sqlite3BtreeGetFilename() is a zero length
+  ** string, it means the main database is :memory: or a temp file.  In 
+  ** that case we do not support atomic multi-file commits, so use the 
+  ** simple case then too.
+  */
+  if( 0==strlen(sqlite3BtreeGetFilename(db->aDb[0].pBt)) || nTrans<=1 ){
+    for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ 
+      Btree *pBt = db->aDb[i].pBt;
+      if( pBt ){
+        rc = sqlite3BtreeCommitPhaseOne(pBt, 0);
+      }
+    }
+
+    /* Do the commit only if all databases successfully complete phase 1. 
+    ** If one of the BtreeCommitPhaseOne() calls fails, this indicates an
+    ** IO error while deleting or truncating a journal file. It is unlikely,
+    ** but could happen. In this case abandon processing and return the error.
+    */
+    for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
+      Btree *pBt = db->aDb[i].pBt;
+      if( pBt ){
+        rc = sqlite3BtreeCommitPhaseTwo(pBt);
+      }
+    }
+    if( rc==SQLITE_OK ){
+      sqlite3VtabCommit(db);
+    }
+  }
+
+  /* The complex case - There is a multi-file write-transaction active.
+  ** This requires a master journal file to ensure the transaction is
+  ** committed atomicly.
+  */
+#ifndef SQLITE_OMIT_DISKIO
+  else{
+    sqlite3_vfs *pVfs = db->pVfs;
+    int needSync = 0;
+    char *zMaster = 0;   /* File-name for the master journal */
+    char const *zMainFile = sqlite3BtreeGetFilename(db->aDb[0].pBt);
+    sqlite3_file *pMaster = 0;
+    i64 offset = 0;
+    int res;
+
+    /* Select a master journal file name */
+    do {
+      u32 random;
+      sqlite3DbFree(db, zMaster);
+      sqlite3_randomness(sizeof(random), &random);
+      zMaster = sqlite3MPrintf(db, "%s-mj%08X", zMainFile, random&0x7fffffff);
+      if( !zMaster ){
+        return SQLITE_NOMEM;
+      }
+      rc = sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS, &res);
+    }while( rc==SQLITE_OK && res );
+    if( rc==SQLITE_OK ){
+      /* Open the master journal. */
+      rc = sqlite3OsOpenMalloc(pVfs, zMaster, &pMaster, 
+          SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
+          SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_MASTER_JOURNAL, 0
+      );
+    }
+    if( rc!=SQLITE_OK ){
+      sqlite3DbFree(db, zMaster);
+      return rc;
+    }
+ 
+    /* Write the name of each database file in the transaction into the new
+    ** master journal file. If an error occurs at this point close
+    ** and delete the master journal file. All the individual journal files
+    ** still have 'null' as the master journal pointer, so they will roll
+    ** back independently if a failure occurs.
+    */
+    for(i=0; i<db->nDb; i++){
+      Btree *pBt = db->aDb[i].pBt;
+      if( i==1 ) continue;   /* Ignore the TEMP database */
+      if( sqlite3BtreeIsInTrans(pBt) ){
+        char const *zFile = sqlite3BtreeGetJournalname(pBt);
+        if( zFile[0]==0 ) continue;  /* Ignore :memory: databases */
+        if( !needSync && !sqlite3BtreeSyncDisabled(pBt) ){
+          needSync = 1;
+        }
+        rc = sqlite3OsWrite(pMaster, zFile, strlen(zFile)+1, offset);
+        offset += strlen(zFile)+1;
+        if( rc!=SQLITE_OK ){
+          sqlite3OsCloseFree(pMaster);
+          sqlite3OsDelete(pVfs, zMaster, 0);
+          sqlite3DbFree(db, zMaster);
+          return rc;
+        }
+      }
+    }
+
+    /* Sync the master journal file. If the IOCAP_SEQUENTIAL device
+    ** flag is set this is not required.
+    */
+    zMainFile = sqlite3BtreeGetDirname(db->aDb[0].pBt);
+    if( (needSync 
+     && (0==(sqlite3OsDeviceCharacteristics(pMaster)&SQLITE_IOCAP_SEQUENTIAL))
+     && (rc=sqlite3OsSync(pMaster, SQLITE_SYNC_NORMAL))!=SQLITE_OK) ){
+      sqlite3OsCloseFree(pMaster);
+      sqlite3OsDelete(pVfs, zMaster, 0);
+      sqlite3DbFree(db, zMaster);
+      return rc;
+    }
+
+    /* Sync all the db files involved in the transaction. The same call
+    ** sets the master journal pointer in each individual journal. If
+    ** an error occurs here, do not delete the master journal file.
+    **
+    ** If the error occurs during the first call to
+    ** sqlite3BtreeCommitPhaseOne(), then there is a chance that the
+    ** master journal file will be orphaned. But we cannot delete it,
+    ** in case the master journal file name was written into the journal
+    ** file before the failure occured.
+    */
+    for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ 
+      Btree *pBt = db->aDb[i].pBt;
+      if( pBt ){
+        rc = sqlite3BtreeCommitPhaseOne(pBt, zMaster);
+      }
+    }
+    sqlite3OsCloseFree(pMaster);
+    if( rc!=SQLITE_OK ){
+      sqlite3DbFree(db, zMaster);
+      return rc;
+    }
+
+    /* Delete the master journal file. This commits the transaction. After
+    ** doing this the directory is synced again before any individual
+    ** transaction files are deleted.
+    */
+    rc = sqlite3OsDelete(pVfs, zMaster, 1);
+    sqlite3DbFree(db, zMaster);
+    zMaster = 0;
+    if( rc ){
+      return rc;
+    }
+
+    /* All files and directories have already been synced, so the following
+    ** calls to sqlite3BtreeCommitPhaseTwo() are only closing files and
+    ** deleting or truncating journals. If something goes wrong while
+    ** this is happening we don't really care. The integrity of the
+    ** transaction is already guaranteed, but some stray 'cold' journals
+    ** may be lying around. Returning an error code won't help matters.
+    */
+    disable_simulated_io_errors();
+    sqlite3BeginBenignMalloc();
+    for(i=0; i<db->nDb; i++){ 
+      Btree *pBt = db->aDb[i].pBt;
+      if( pBt ){
+        sqlite3BtreeCommitPhaseTwo(pBt);
+      }
+    }
+    sqlite3EndBenignMalloc();
+    enable_simulated_io_errors();
+
+    sqlite3VtabCommit(db);
+  }
+#endif
+
+  return rc;
+}
+
+/* 
+** This routine checks that the sqlite3.activeVdbeCnt count variable
+** matches the number of vdbe's in the list sqlite3.pVdbe that are
+** currently active. An assertion fails if the two counts do not match.
+** This is an internal self-check only - it is not an essential processing
+** step.
+**
+** This is a no-op if NDEBUG is defined.
+*/
+#ifndef NDEBUG
+static void checkActiveVdbeCnt(sqlite3 *db){
+  Vdbe *p;
+  int cnt = 0;
+  p = db->pVdbe;
+  while( p ){
+    if( p->magic==VDBE_MAGIC_RUN && p->pc>=0 ){
+      cnt++;
+    }
+    p = p->pNext;
+  }
+  assert( cnt==db->activeVdbeCnt );
+}
+#else
+#define checkActiveVdbeCnt(x)
+#endif
+
+/*
+** For every Btree that in database connection db which 
+** has been modified, "trip" or invalidate each cursor in
+** that Btree might have been modified so that the cursor
+** can never be used again.  This happens when a rollback
+*** occurs.  We have to trip all the other cursors, even
+** cursor from other VMs in different database connections,
+** so that none of them try to use the data at which they
+** were pointing and which now may have been changed due
+** to the rollback.
+**
+** Remember that a rollback can delete tables complete and
+** reorder rootpages.  So it is not sufficient just to save
+** the state of the cursor.  We have to invalidate the cursor
+** so that it is never used again.
+*/
+static void invalidateCursorsOnModifiedBtrees(sqlite3 *db){
+  int i;
+  for(i=0; i<db->nDb; i++){
+    Btree *p = db->aDb[i].pBt;
+    if( p && sqlite3BtreeIsInTrans(p) ){
+      sqlite3BtreeTripAllCursors(p, SQLITE_ABORT);
+    }
+  }
+}
+
+/*
+** This routine is called the when a VDBE tries to halt.  If the VDBE
+** has made changes and is in autocommit mode, then commit those
+** changes.  If a rollback is needed, then do the rollback.
+**
+** This routine is the only way to move the state of a VM from
+** SQLITE_MAGIC_RUN to SQLITE_MAGIC_HALT.  It is harmless to
+** call this on a VM that is in the SQLITE_MAGIC_HALT state.
+**
+** Return an error code.  If the commit could not complete because of
+** lock contention, return SQLITE_BUSY.  If SQLITE_BUSY is returned, it
+** means the close did not happen and needs to be repeated.
+*/
+int sqlite3VdbeHalt(Vdbe *p){
+  sqlite3 *db = p->db;
+  int i;
+  int (*xFunc)(Btree *pBt) = 0;  /* Function to call on each btree backend */
+  int isSpecialError;            /* Set to true if SQLITE_NOMEM or IOERR */
+
+  /* This function contains the logic that determines if a statement or
+  ** transaction will be committed or rolled back as a result of the
+  ** execution of this virtual machine. 
+  **
+  ** If any of the following errors occur:
+  **
+  **     SQLITE_NOMEM
+  **     SQLITE_IOERR
+  **     SQLITE_FULL
+  **     SQLITE_INTERRUPT
+  **
+  ** Then the internal cache might have been left in an inconsistent
+  ** state.  We need to rollback the statement transaction, if there is
+  ** one, or the complete transaction if there is no statement transaction.
+  */
+
+  if( p->db->mallocFailed ){
+    p->rc = SQLITE_NOMEM;
+  }
+  closeAllCursorsExceptActiveVtabs(p);
+  if( p->magic!=VDBE_MAGIC_RUN ){
+    return SQLITE_OK;
+  }
+  checkActiveVdbeCnt(db);
+
+  /* No commit or rollback needed if the program never started */
+  if( p->pc>=0 ){
+    int mrc;   /* Primary error code from p->rc */
+
+    /* Lock all btrees used by the statement */
+    sqlite3BtreeMutexArrayEnter(&p->aMutex);
+
+    /* Check for one of the special errors */
+    mrc = p->rc & 0xff;
+    isSpecialError = mrc==SQLITE_NOMEM || mrc==SQLITE_IOERR
+                     || mrc==SQLITE_INTERRUPT || mrc==SQLITE_FULL;
+    if( isSpecialError ){
+      /* This loop does static analysis of the query to see which of the
+      ** following three categories it falls into:
+      **
+      **     Read-only
+      **     Query with statement journal
+      **     Query without statement journal
+      **
+      ** We could do something more elegant than this static analysis (i.e.
+      ** store the type of query as part of the compliation phase), but 
+      ** handling malloc() or IO failure is a fairly obscure edge case so 
+      ** this is probably easier. Todo: Might be an opportunity to reduce 
+      ** code size a very small amount though...
+      */
+      int notReadOnly = 0;
+      int isStatement = 0;
+      assert(p->aOp || p->nOp==0);
+      for(i=0; i<p->nOp; i++){ 
+        switch( p->aOp[i].opcode ){
+          case OP_Transaction:
+            notReadOnly |= p->aOp[i].p2;
+            break;
+          case OP_Statement:
+            isStatement = 1;
+            break;
+        }
+      }
+
+   
+      /* If the query was read-only, we need do no rollback at all. Otherwise,
+      ** proceed with the special handling.
+      */
+      if( notReadOnly || mrc!=SQLITE_INTERRUPT ){
+        if( p->rc==SQLITE_IOERR_BLOCKED && isStatement ){
+          xFunc = sqlite3BtreeRollbackStmt;
+          p->rc = SQLITE_BUSY;
+        } else if( (mrc==SQLITE_NOMEM || mrc==SQLITE_FULL) && isStatement ){
+          xFunc = sqlite3BtreeRollbackStmt;
+        }else{
+          /* We are forced to roll back the active transaction. Before doing
+          ** so, abort any other statements this handle currently has active.
+          */
+          invalidateCursorsOnModifiedBtrees(db);
+          sqlite3RollbackAll(db);
+          db->autoCommit = 1;
+        }
+      }
+    }
+  
+    /* If the auto-commit flag is set and this is the only active vdbe, then
+    ** we do either a commit or rollback of the current transaction. 
+    **
+    ** Note: This block also runs if one of the special errors handled 
+    ** above has occured. 
+    */
+    if( db->autoCommit && db->activeVdbeCnt==1 ){
+      if( p->rc==SQLITE_OK || (p->errorAction==OE_Fail && !isSpecialError) ){
+        /* The auto-commit flag is true, and the vdbe program was 
+        ** successful or hit an 'OR FAIL' constraint. This means a commit 
+        ** is required.
+        */
+        int rc = vdbeCommit(db, p);
+        if( rc==SQLITE_BUSY ){
+          sqlite3BtreeMutexArrayLeave(&p->aMutex);
+          return SQLITE_BUSY;
+        }else if( rc!=SQLITE_OK ){
+          p->rc = rc;
+          sqlite3RollbackAll(db);
+        }else{
+          sqlite3CommitInternalChanges(db);
+        }
+      }else{
+        sqlite3RollbackAll(db);
+      }
+    }else if( !xFunc ){
+      if( p->rc==SQLITE_OK || p->errorAction==OE_Fail ){
+        if( p->openedStatement ){
+          xFunc = sqlite3BtreeCommitStmt;
+        } 
+      }else if( p->errorAction==OE_Abort ){
+        xFunc = sqlite3BtreeRollbackStmt;
+      }else{
+        invalidateCursorsOnModifiedBtrees(db);
+        sqlite3RollbackAll(db);
+        db->autoCommit = 1;
+      }
+    }
+  
+    /* If xFunc is not NULL, then it is one of sqlite3BtreeRollbackStmt or
+    ** sqlite3BtreeCommitStmt. Call it once on each backend. If an error occurs
+    ** and the return code is still SQLITE_OK, set the return code to the new
+    ** error value.
+    */
+    assert(!xFunc ||
+      xFunc==sqlite3BtreeCommitStmt ||
+      xFunc==sqlite3BtreeRollbackStmt
+    );
+    for(i=0; xFunc && i<db->nDb; i++){ 
+      int rc;
+      Btree *pBt = db->aDb[i].pBt;
+      if( pBt ){
+        rc = xFunc(pBt);
+        if( rc && (p->rc==SQLITE_OK || p->rc==SQLITE_CONSTRAINT) ){
+          p->rc = rc;
+          sqlite3DbFree(db, p->zErrMsg);
+          p->zErrMsg = 0;
+        }
+      }
+    }
+  
+    /* If this was an INSERT, UPDATE or DELETE and the statement was committed, 
+    ** set the change counter. 
+    */
+    if( p->changeCntOn && p->pc>=0 ){
+      if( !xFunc || xFunc==sqlite3BtreeCommitStmt ){
+        sqlite3VdbeSetChanges(db, p->nChange);
+      }else{
+        sqlite3VdbeSetChanges(db, 0);
+      }
+      p->nChange = 0;
+    }
+  
+    /* Rollback or commit any schema changes that occurred. */
+    if( p->rc!=SQLITE_OK && db->flags&SQLITE_InternChanges ){
+      sqlite3ResetInternalSchema(db, 0);
+      db->flags = (db->flags | SQLITE_InternChanges);
+    }
+
+    /* Release the locks */
+    sqlite3BtreeMutexArrayLeave(&p->aMutex);
+  }
+
+  /* We have successfully halted and closed the VM.  Record this fact. */
+  if( p->pc>=0 ){
+    db->activeVdbeCnt--;
+  }
+  p->magic = VDBE_MAGIC_HALT;
+  checkActiveVdbeCnt(db);
+  if( p->db->mallocFailed ){
+    p->rc = SQLITE_NOMEM;
+  }
+
+  return SQLITE_OK;
+}
+
+
+/*
+** Each VDBE holds the result of the most recent sqlite3_step() call
+** in p->rc.  This routine sets that result back to SQLITE_OK.
+*/
+void sqlite3VdbeResetStepResult(Vdbe *p){
+  p->rc = SQLITE_OK;
+}
+
+/*
+** Clean up a VDBE after execution but do not delete the VDBE just yet.
+** Write any error messages into *pzErrMsg.  Return the result code.
+**
+** After this routine is run, the VDBE should be ready to be executed
+** again.
+**
+** To look at it another way, this routine resets the state of the
+** virtual machine from VDBE_MAGIC_RUN or VDBE_MAGIC_HALT back to
+** VDBE_MAGIC_INIT.
+*/
+int sqlite3VdbeReset(Vdbe *p){
+  sqlite3 *db;
+  db = p->db;
+
+  /* If the VM did not run to completion or if it encountered an
+  ** error, then it might not have been halted properly.  So halt
+  ** it now.
+  */
+  (void)sqlite3SafetyOn(db);
+  sqlite3VdbeHalt(p);
+  (void)sqlite3SafetyOff(db);
+
+  /* If the VDBE has be run even partially, then transfer the error code
+  ** and error message from the VDBE into the main database structure.  But
+  ** if the VDBE has just been set to run but has not actually executed any
+  ** instructions yet, leave the main database error information unchanged.
+  */
+  if( p->pc>=0 ){
+    if( p->zErrMsg ){
+      sqlite3ValueSetStr(db->pErr,-1,p->zErrMsg,SQLITE_UTF8,SQLITE_TRANSIENT);
+      db->errCode = p->rc;
+      sqlite3DbFree(db, p->zErrMsg);
+      p->zErrMsg = 0;
+    }else if( p->rc ){
+      sqlite3Error(db, p->rc, 0);
+    }else{
+      sqlite3Error(db, SQLITE_OK, 0);
+    }
+  }else if( p->rc && p->expired ){
+    /* The expired flag was set on the VDBE before the first call
+    ** to sqlite3_step(). For consistency (since sqlite3_step() was
+    ** called), set the database error in this case as well.
+    */
+    sqlite3Error(db, p->rc, 0);
+    sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);
+    sqlite3DbFree(db, p->zErrMsg);
+    p->zErrMsg = 0;
+  }
+
+  /* Reclaim all memory used by the VDBE
+  */
+  Cleanup(p);
+
+  /* Save profiling information from this VDBE run.
+  */
+#ifdef VDBE_PROFILE
+  {
+    FILE *out = fopen("vdbe_profile.out", "a");
+    if( out ){
+      int i;
+      fprintf(out, "---- ");
+      for(i=0; i<p->nOp; i++){
+        fprintf(out, "%02x", p->aOp[i].opcode);
+      }
+      fprintf(out, "\n");
+      for(i=0; i<p->nOp; i++){
+        fprintf(out, "%6d %10lld %8lld ",
+           p->aOp[i].cnt,
+           p->aOp[i].cycles,
+           p->aOp[i].cnt>0 ? p->aOp[i].cycles/p->aOp[i].cnt : 0
+        );
+        sqlite3VdbePrintOp(out, i, &p->aOp[i]);
+      }
+      fclose(out);
+    }
+  }
+#endif
+  p->magic = VDBE_MAGIC_INIT;
+  return p->rc & db->errMask;
+}
+ 
+/*
+** Clean up and delete a VDBE after execution.  Return an integer which is
+** the result code.  Write any error message text into *pzErrMsg.
+*/
+int sqlite3VdbeFinalize(Vdbe *p){
+  int rc = SQLITE_OK;
+  if( p->magic==VDBE_MAGIC_RUN || p->magic==VDBE_MAGIC_HALT ){
+    rc = sqlite3VdbeReset(p);
+    assert( (rc & p->db->errMask)==rc );
+  }else if( p->magic!=VDBE_MAGIC_INIT ){
+    return SQLITE_MISUSE;
+  }
+  sqlite3VdbeDelete(p);
+  return rc;
+}
+
+/*
+** Call the destructor for each auxdata entry in pVdbeFunc for which
+** the corresponding bit in mask is clear.  Auxdata entries beyond 31
+** are always destroyed.  To destroy all auxdata entries, call this
+** routine with mask==0.
+*/
+void sqlite3VdbeDeleteAuxData(VdbeFunc *pVdbeFunc, int mask){
+  int i;
+  for(i=0; i<pVdbeFunc->nAux; i++){
+    struct AuxData *pAux = &pVdbeFunc->apAux[i];
+    if( (i>31 || !(mask&(1<<i))) && pAux->pAux ){
+      if( pAux->xDelete ){
+        pAux->xDelete(pAux->pAux);
+      }
+      pAux->pAux = 0;
+    }
+  }
+}
+
+/*
+** Delete an entire VDBE.
+*/
+void sqlite3VdbeDelete(Vdbe *p){
+  int i;
+  sqlite3 *db;
+
+  if( p==0 ) return;
+  db = p->db;
+  if( p->pPrev ){
+    p->pPrev->pNext = p->pNext;
+  }else{
+    assert( db->pVdbe==p );
+    db->pVdbe = p->pNext;
+  }
+  if( p->pNext ){
+    p->pNext->pPrev = p->pPrev;
+  }
+  if( p->aOp ){
+    Op *pOp = p->aOp;
+    for(i=0; i<p->nOp; i++, pOp++){
+      freeP4(db, pOp->p4type, pOp->p4.p);
+#ifdef SQLITE_DEBUG
+      sqlite3DbFree(db, pOp->zComment);
+#endif     
+    }
+    sqlite3DbFree(db, p->aOp);
+  }
+  releaseMemArray(p->aVar, p->nVar);
+  sqlite3DbFree(db, p->aLabel);
+  if( p->aMem ){
+    sqlite3DbFree(db, &p->aMem[1]);
+  }
+  releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
+  sqlite3DbFree(db, p->aColName);
+  sqlite3DbFree(db, p->zSql);
+  p->magic = VDBE_MAGIC_DEAD;
+  sqlite3DbFree(db, p);
+}
+
+/*
+** If a MoveTo operation is pending on the given cursor, then do that
+** MoveTo now.  Return an error code.  If no MoveTo is pending, this
+** routine does nothing and returns SQLITE_OK.
+*/
+int sqlite3VdbeCursorMoveto(Cursor *p){
+  if( p->deferredMoveto ){
+    int res, rc;
+#ifdef SQLITE_TEST
+    extern int sqlite3_search_count;
+#endif
+    assert( p->isTable );
+    rc = sqlite3BtreeMoveto(p->pCursor, 0, 0, p->movetoTarget, 0, &res);
+    if( rc ) return rc;
+    *p->pIncrKey = 0;
+    p->lastRowid = keyToInt(p->movetoTarget);
+    p->rowidIsValid = res==0;
+    if( res<0 ){
+      rc = sqlite3BtreeNext(p->pCursor, &res);
+      if( rc ) return rc;
+    }
+#ifdef SQLITE_TEST
+    sqlite3_search_count++;
+#endif
+    p->deferredMoveto = 0;
+    p->cacheStatus = CACHE_STALE;
+  }else if( p->pCursor ){
+    int hasMoved;
+    int rc = sqlite3BtreeCursorHasMoved(p->pCursor, &hasMoved);
+    if( rc ) return rc;
+    if( hasMoved ){
+      p->cacheStatus = CACHE_STALE;
+      p->nullRow = 1;
+    }
+  }
+  return SQLITE_OK;
+}
+
+/*
+** The following functions:
+**
+** sqlite3VdbeSerialType()
+** sqlite3VdbeSerialTypeLen()
+** sqlite3VdbeSerialLen()
+** sqlite3VdbeSerialPut()
+** sqlite3VdbeSerialGet()
+**
+** encapsulate the code that serializes values for storage in SQLite
+** data and index records. Each serialized value consists of a
+** 'serial-type' and a blob of data. The serial type is an 8-byte unsigned
+** integer, stored as a varint.
+**
+** In an SQLite index record, the serial type is stored directly before
+** the blob of data that it corresponds to. In a table record, all serial
+** types are stored at the start of the record, and the blobs of data at
+** the end. Hence these functions allow the caller to handle the
+** serial-type and data blob seperately.
+**
+** The following table describes the various storage classes for data:
+**
+**   serial type        bytes of data      type
+**   --------------     ---------------    ---------------
+**      0                     0            NULL
+**      1                     1            signed integer
+**      2                     2            signed integer
+**      3                     3            signed integer
+**      4                     4            signed integer
+**      5                     6            signed integer
+**      6                     8            signed integer
+**      7                     8            IEEE float
+**      8                     0            Integer constant 0
+**      9                     0            Integer constant 1
+**     10,11                               reserved for expansion
+**    N>=12 and even       (N-12)/2        BLOB
+**    N>=13 and odd        (N-13)/2        text
+**
+** The 8 and 9 types were added in 3.3.0, file format 4.  Prior versions
+** of SQLite will not understand those serial types.
+*/
+
+/*
+** Return the serial-type for the value stored in pMem.
+*/
+u32 sqlite3VdbeSerialType(Mem *pMem, int file_format){
+  int flags = pMem->flags;
+  int n;
+
+  if( flags&MEM_Null ){
+    return 0;
+  }
+  if( flags&MEM_Int ){
+    /* Figure out whether to use 1, 2, 4, 6 or 8 bytes. */
+#   define MAX_6BYTE ((((i64)0x00008000)<<32)-1)
+    i64 i = pMem->u.i;
+    u64 u;
+    if( file_format>=4 && (i&1)==i ){
+      return 8+i;
+    }
+    u = i<0 ? -i : i;
+    if( u<=127 ) return 1;
+    if( u<=32767 ) return 2;
+    if( u<=8388607 ) return 3;
+    if( u<=2147483647 ) return 4;
+    if( u<=MAX_6BYTE ) return 5;
+    return 6;
+  }
+  if( flags&MEM_Real ){
+    return 7;
+  }
+  assert( flags&(MEM_Str|MEM_Blob) );
+  n = pMem->n;
+  if( flags & MEM_Zero ){
+    n += pMem->u.i;
+  }
+  assert( n>=0 );
+  return ((n*2) + 12 + ((flags&MEM_Str)!=0));
+}
+
+/*
+** Return the length of the data corresponding to the supplied serial-type.
+*/
+int sqlite3VdbeSerialTypeLen(u32 serial_type){
+  if( serial_type>=12 ){
+    return (serial_type-12)/2;
+  }else{
+    static const u8 aSize[] = { 0, 1, 2, 3, 4, 6, 8, 8, 0, 0, 0, 0 };
+    return aSize[serial_type];
+  }
+}
+
+/*
+** If we are on an architecture with mixed-endian floating 
+** points (ex: ARM7) then swap the lower 4 bytes with the 
+** upper 4 bytes.  Return the result.
+**
+** For most architectures, this is a no-op.
+**
+** (later):  It is reported to me that the mixed-endian problem
+** on ARM7 is an issue with GCC, not with the ARM7 chip.  It seems
+** that early versions of GCC stored the two words of a 64-bit
+** float in the wrong order.  And that error has been propagated
+** ever since.  The blame is not necessarily with GCC, though.
+** GCC might have just copying the problem from a prior compiler.
+** I am also told that newer versions of GCC that follow a different
+** ABI get the byte order right.
+**
+** Developers using SQLite on an ARM7 should compile and run their
+** application using -DSQLITE_DEBUG=1 at least once.  With DEBUG
+** enabled, some asserts below will ensure that the byte order of
+** floating point values is correct.
+**
+** (2007-08-30)  Frank van Vugt has studied this problem closely
+** and has send his findings to the SQLite developers.  Frank
+** writes that some Linux kernels offer floating point hardware
+** emulation that uses only 32-bit mantissas instead of a full 
+** 48-bits as required by the IEEE standard.  (This is the
+** CONFIG_FPE_FASTFPE option.)  On such systems, floating point
+** byte swapping becomes very complicated.  To avoid problems,
+** the necessary byte swapping is carried out using a 64-bit integer
+** rather than a 64-bit float.  Frank assures us that the code here
+** works for him.  We, the developers, have no way to independently
+** verify this, but Frank seems to know what he is talking about
+** so we trust him.
+*/
+#ifdef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
+static u64 floatSwap(u64 in){
+  union {
+    u64 r;
+    u32 i[2];
+  } u;
+  u32 t;
+
+  u.r = in;
+  t = u.i[0];
+  u.i[0] = u.i[1];
+  u.i[1] = t;
+  return u.r;
+}
+# define swapMixedEndianFloat(X)  X = floatSwap(X)
+#else
+# define swapMixedEndianFloat(X)
+#endif
+
+/*
+** Write the serialized data blob for the value stored in pMem into 
+** buf. It is assumed that the caller has allocated sufficient space.
+** Return the number of bytes written.
+**
+** nBuf is the amount of space left in buf[].  nBuf must always be
+** large enough to hold the entire field.  Except, if the field is
+** a blob with a zero-filled tail, then buf[] might be just the right
+** size to hold everything except for the zero-filled tail.  If buf[]
+** is only big enough to hold the non-zero prefix, then only write that
+** prefix into buf[].  But if buf[] is large enough to hold both the
+** prefix and the tail then write the prefix and set the tail to all
+** zeros.
+**
+** Return the number of bytes actually written into buf[].  The number
+** of bytes in the zero-filled tail is included in the return value only
+** if those bytes were zeroed in buf[].
+*/ 
+int sqlite3VdbeSerialPut(u8 *buf, int nBuf, Mem *pMem, int file_format){
+  u32 serial_type = sqlite3VdbeSerialType(pMem, file_format);
+  int len;
+
+  /* Integer and Real */
+  if( serial_type<=7 && serial_type>0 ){
+    u64 v;
+    int i;
+    if( serial_type==7 ){
+      assert( sizeof(v)==sizeof(pMem->r) );
+      memcpy(&v, &pMem->r, sizeof(v));
+      swapMixedEndianFloat(v);
+    }else{
+      v = pMem->u.i;
+    }
+    len = i = sqlite3VdbeSerialTypeLen(serial_type);
+    assert( len<=nBuf );
+    while( i-- ){
+      buf[i] = (v&0xFF);
+      v >>= 8;
+    }
+    return len;
+  }
+
+  /* String or blob */
+  if( serial_type>=12 ){
+    assert( pMem->n + ((pMem->flags & MEM_Zero)?pMem->u.i:0)
+             == sqlite3VdbeSerialTypeLen(serial_type) );
+    assert( pMem->n<=nBuf );
+    len = pMem->n;
+    memcpy(buf, pMem->z, len);
+    if( pMem->flags & MEM_Zero ){
+      len += pMem->u.i;
+      if( len>nBuf ){
+        len = nBuf;
+      }
+      memset(&buf[pMem->n], 0, len-pMem->n);
+    }
+    return len;
+  }
+
+  /* NULL or constants 0 or 1 */
+  return 0;
+}
+
+/*
+** Deserialize the data blob pointed to by buf as serial type serial_type
+** and store the result in pMem.  Return the number of bytes read.
+*/ 
+int sqlite3VdbeSerialGet(
+  const unsigned char *buf,     /* Buffer to deserialize from */
+  u32 serial_type,              /* Serial type to deserialize */
+  Mem *pMem                     /* Memory cell to write value into */
+){
+  switch( serial_type ){
+    case 10:   /* Reserved for future use */
+    case 11:   /* Reserved for future use */
+    case 0: {  /* NULL */
+      pMem->flags = MEM_Null;
+      break;
+    }
+    case 1: { /* 1-byte signed integer */
+      pMem->u.i = (signed char)buf[0];
+      pMem->flags = MEM_Int;
+      return 1;
+    }
+    case 2: { /* 2-byte signed integer */
+      pMem->u.i = (((signed char)buf[0])<<8) | buf[1];
+      pMem->flags = MEM_Int;
+      return 2;
+    }
+    case 3: { /* 3-byte signed integer */
+      pMem->u.i = (((signed char)buf[0])<<16) | (buf[1]<<8) | buf[2];
+      pMem->flags = MEM_Int;
+      return 3;
+    }
+    case 4: { /* 4-byte signed integer */
+      pMem->u.i = (buf[0]<<24) | (buf[1]<<16) | (buf[2]<<8) | buf[3];
+      pMem->flags = MEM_Int;
+      return 4;
+    }
+    case 5: { /* 6-byte signed integer */
+      u64 x = (((signed char)buf[0])<<8) | buf[1];
+      u32 y = (buf[2]<<24) | (buf[3]<<16) | (buf[4]<<8) | buf[5];
+      x = (x<<32) | y;
+      pMem->u.i = *(i64*)&x;
+      pMem->flags = MEM_Int;
+      return 6;
+    }
+    case 6:   /* 8-byte signed integer */
+    case 7: { /* IEEE floating point */
+      u64 x;
+      u32 y;
+#if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)
+      /* Verify that integers and floating point values use the same
+      ** byte order.  Or, that if SQLITE_MIXED_ENDIAN_64BIT_FLOAT is
+      ** defined that 64-bit floating point values really are mixed
+      ** endian.
+      */
+      static const u64 t1 = ((u64)0x3ff00000)<<32;
+      static const double r1 = 1.0;
+      u64 t2 = t1;
+      swapMixedEndianFloat(t2);
+      assert( sizeof(r1)==sizeof(t2) && memcmp(&r1, &t2, sizeof(r1))==0 );
+#endif
+
+      x = (buf[0]<<24) | (buf[1]<<16) | (buf[2]<<8) | buf[3];
+      y = (buf[4]<<24) | (buf[5]<<16) | (buf[6]<<8) | buf[7];
+      x = (x<<32) | y;
+      if( serial_type==6 ){
+        pMem->u.i = *(i64*)&x;
+        pMem->flags = MEM_Int;
+      }else{
+        assert( sizeof(x)==8 && sizeof(pMem->r)==8 );
+        swapMixedEndianFloat(x);
+        memcpy(&pMem->r, &x, sizeof(x));
+        pMem->flags = sqlite3IsNaN(pMem->r) ? MEM_Null : MEM_Real;
+      }
+      return 8;
+    }
+    case 8:    /* Integer 0 */
+    case 9: {  /* Integer 1 */
+      pMem->u.i = serial_type-8;
+      pMem->flags = MEM_Int;
+      return 0;
+    }
+    default: {
+      int len = (serial_type-12)/2;
+      pMem->z = (char *)buf;
+      pMem->n = len;
+      pMem->xDel = 0;
+      if( serial_type&0x01 ){
+        pMem->flags = MEM_Str | MEM_Ephem;
+      }else{
+        pMem->flags = MEM_Blob | MEM_Ephem;
+      }
+      return len;
+    }
+  }
+  return 0;
+}
+
+
+/*
+** Given the nKey-byte encoding of a record in pKey[], parse the
+** record into a UnpackedRecord structure.  Return a pointer to
+** that structure.
+**
+** The calling function might provide szSpace bytes of memory
+** space at pSpace.  This space can be used to hold the returned
+** VDbeParsedRecord structure if it is large enough.  If it is
+** not big enough, space is obtained from sqlite3_malloc().
+**
+** The returned structure should be closed by a call to
+** sqlite3VdbeDeleteUnpackedRecord().
+*/ 
+UnpackedRecord *sqlite3VdbeRecordUnpack(
+  KeyInfo *pKeyInfo,     /* Information about the record format */
+  int nKey,              /* Size of the binary record */
+  const void *pKey,      /* The binary record */
+  void *pSpace,          /* Space available to hold resulting object */
+  int szSpace            /* Size of pSpace[] in bytes */
+){
+  const unsigned char *aKey = (const unsigned char *)pKey;
+  UnpackedRecord *p;
+  int nByte;
+  int idx, d;
+  u16 u;                 /* Unsigned loop counter */
+  u32 szHdr;
+  Mem *pMem;
+  
+  assert( sizeof(Mem)>sizeof(*p) );
+  nByte = sizeof(Mem)*(pKeyInfo->nField+2);
+  if( nByte>szSpace ){
+    p = sqlite3DbMallocRaw(pKeyInfo->db, nByte);
+    if( p==0 ) return 0;
+    p->needFree = 1;
+  }else{
+    p = pSpace;
+    p->needFree = 0;
+  }
+  p->pKeyInfo = pKeyInfo;
+  p->nField = pKeyInfo->nField + 1;
+  p->needDestroy = 1;
+  p->aMem = pMem = &((Mem*)p)[1];
+  idx = getVarint32(aKey, szHdr);
+  d = szHdr;
+  u = 0;
+  while( idx<szHdr && u<p->nField ){
+    u32 serial_type;
+
+    idx += getVarint32( aKey+idx, serial_type);
+    if( d>=nKey && sqlite3VdbeSerialTypeLen(serial_type)>0 ) break;
+    pMem->enc = pKeyInfo->enc;
+    pMem->db = pKeyInfo->db;
+    pMem->flags = 0;
+    pMem->zMalloc = 0;
+    d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
+    pMem++;
+    u++;
+  }
+  p->nField = u;
+  return (void*)p;
+}
+
+/*
+** This routine destroys a UnpackedRecord object
+*/
+void sqlite3VdbeDeleteUnpackedRecord(UnpackedRecord *p){
+  if( p ){
+    if( p->needDestroy ){
+      int i;
+      Mem *pMem;
+      for(i=0, pMem=p->aMem; i<p->nField; i++, pMem++){
+        if( pMem->zMalloc ){
+          sqlite3VdbeMemRelease(pMem);
+        }
+      }
+    }
+    if( p->needFree ){
+      sqlite3DbFree(p->pKeyInfo->db, p);
+    }
+  }
+}
+
+/*
+** This function compares the two table rows or index records
+** specified by {nKey1, pKey1} and pPKey2.  It returns a negative, zero
+** or positive integer if {nKey1, pKey1} is less than, equal to or 
+** greater than pPKey2.  The {nKey1, pKey1} key must be a blob
+** created by th OP_MakeRecord opcode of the VDBE.  The pPKey2
+** key must be a parsed key such as obtained from
+** sqlite3VdbeParseRecord.
+**
+** Key1 and Key2 do not have to contain the same number of fields.
+** But if the lengths differ, Key2 must be the shorter of the two.
+**
+** Historical note: In earlier versions of this routine both Key1
+** and Key2 were blobs obtained from OP_MakeRecord.  But we found
+** that in typical use the same Key2 would be submitted multiple times
+** in a row.  So an optimization was added to parse the Key2 key
+** separately and submit the parsed version.  In this way, we avoid
+** parsing the same Key2 multiple times in a row.
+*/
+int sqlite3VdbeRecordCompare(
+  int nKey1, const void *pKey1, 
+  UnpackedRecord *pPKey2
+){
+  u32 d1;            /* Offset into aKey[] of next data element */
+  u32 idx1;          /* Offset into aKey[] of next header element */
+  u32 szHdr1;        /* Number of bytes in header */
+  int i = 0;
+  int nField;
+  int rc = 0;
+  const unsigned char *aKey1 = (const unsigned char *)pKey1;
+  KeyInfo *pKeyInfo;
+  Mem mem1;
+
+  pKeyInfo = pPKey2->pKeyInfo;
+  mem1.enc = pKeyInfo->enc;
+  mem1.db = pKeyInfo->db;
+  mem1.flags = 0;
+  mem1.zMalloc = 0;
+  
+  idx1 = getVarint32(aKey1, szHdr1);
+  d1 = szHdr1;
+  nField = pKeyInfo->nField;
+  while( idx1<szHdr1 && i<pPKey2->nField ){
+    u32 serial_type1;
+
+    /* Read the serial types for the next element in each key. */
+    idx1 += getVarint32( aKey1+idx1, serial_type1 );
+    if( d1>=nKey1 && sqlite3VdbeSerialTypeLen(serial_type1)>0 ) break;
+
+    /* Extract the values to be compared.
+    */
+    d1 += sqlite3VdbeSerialGet(&aKey1[d1], serial_type1, &mem1);
+
+    /* Do the comparison
+    */
+    rc = sqlite3MemCompare(&mem1, &pPKey2->aMem[i],
+                           i<nField ? pKeyInfo->aColl[i] : 0);
+    if( rc!=0 ){
+      break;
+    }
+    i++;
+  }
+  if( mem1.zMalloc ) sqlite3VdbeMemRelease(&mem1);
+
+  /* One of the keys ran out of fields, but all the fields up to that point
+  ** were equal. If the incrKey flag is true, then the second key is
+  ** treated as larger.
+  */
+  if( rc==0 ){
+    if( pKeyInfo->incrKey ){
+      rc = -1;
+    }else if( !pKeyInfo->prefixIsEqual ){
+      if( d1<nKey1 ){
+        rc = 1;
+      }
+    }
+  }else if( pKeyInfo->aSortOrder && i<pKeyInfo->nField
+               && pKeyInfo->aSortOrder[i] ){
+    rc = -rc;
+  }
+
+  return rc;
+}
+
+/*
+** The argument is an index entry composed using the OP_MakeRecord opcode.
+** The last entry in this record should be an integer (specifically
+** an integer rowid).  This routine returns the number of bytes in
+** that integer.
+*/
+int sqlite3VdbeIdxRowidLen(const u8 *aKey, int nKey, int *pRowidLen){
+  u32 szHdr;        /* Size of the header */
+  u32 typeRowid;    /* Serial type of the rowid */
+
+  (void)getVarint32(aKey, szHdr);
+  if( szHdr>nKey ){
+    return SQLITE_CORRUPT_BKPT;
+  }
+  (void)getVarint32(&aKey[szHdr-1], typeRowid);
+  *pRowidLen = sqlite3VdbeSerialTypeLen(typeRowid);
+  return SQLITE_OK;
+}
+  
+
+/*
+** pCur points at an index entry created using the OP_MakeRecord opcode.
+** Read the rowid (the last field in the record) and store it in *rowid.
+** Return SQLITE_OK if everything works, or an error code otherwise.
+*/
+int sqlite3VdbeIdxRowid(BtCursor *pCur, i64 *rowid){
+  i64 nCellKey = 0;
+  int rc;
+  u32 szHdr;        /* Size of the header */
+  u32 typeRowid;    /* Serial type of the rowid */
+  u32 lenRowid;     /* Size of the rowid */
+  Mem m, v;
+
+  sqlite3BtreeKeySize(pCur, &nCellKey);
+  if( nCellKey<=0 ){
+    return SQLITE_CORRUPT_BKPT;
+  }
+  m.flags = 0;
+  m.db = 0;
+  m.zMalloc = 0;
+  rc = sqlite3VdbeMemFromBtree(pCur, 0, nCellKey, 1, &m);
+  if( rc ){
+    return rc;
+  }
+  (void)getVarint32((u8*)m.z, szHdr);
+  (void)getVarint32((u8*)&m.z[szHdr-1], typeRowid);
+  lenRowid = sqlite3VdbeSerialTypeLen(typeRowid);
+  sqlite3VdbeSerialGet((u8*)&m.z[m.n-lenRowid], typeRowid, &v);
+  *rowid = v.u.i;
+  sqlite3VdbeMemRelease(&m);
+  return SQLITE_OK;
+}
+
+/*
+** Compare the key of the index entry that cursor pC is point to against
+** the key string in pKey (of length nKey).  Write into *pRes a number
+** that is negative, zero, or positive if pC is less than, equal to,
+** or greater than pKey.  Return SQLITE_OK on success.
+**
+** pKey is either created without a rowid or is truncated so that it
+** omits the rowid at the end.  The rowid at the end of the index entry
+** is ignored as well.
+*/
+int sqlite3VdbeIdxKeyCompare(
+  Cursor *pC,                 /* The cursor to compare against */
+  UnpackedRecord *pUnpacked,
+  int nKey, const u8 *pKey,   /* The key to compare */
+  int *res                    /* Write the comparison result here */
+){
+  i64 nCellKey = 0;
+  int rc;
+  BtCursor *pCur = pC->pCursor;
+  int lenRowid;
+  Mem m;
+  UnpackedRecord *pRec;
+  char zSpace[200];
+
+  sqlite3BtreeKeySize(pCur, &nCellKey);
+  if( nCellKey<=0 ){
+    *res = 0;
+    return SQLITE_OK;
+  }
+  m.db = 0;
+  m.flags = 0;
+  m.zMalloc = 0;
+  if( (rc = sqlite3VdbeMemFromBtree(pC->pCursor, 0, nCellKey, 1, &m))
+   || (rc = sqlite3VdbeIdxRowidLen((u8*)m.z, m.n, &lenRowid))
+  ){
+    return rc;
+  }
+  if( !pUnpacked ){
+    pRec = sqlite3VdbeRecordUnpack(pC->pKeyInfo, nKey, pKey,
+                                zSpace, sizeof(zSpace));
+  }else{
+    pRec = pUnpacked;
+  }
+  if( pRec==0 ){
+    return SQLITE_NOMEM;
+  }
+  *res = sqlite3VdbeRecordCompare(m.n-lenRowid, m.z, pRec);
+  if( !pUnpacked ){
+    sqlite3VdbeDeleteUnpackedRecord(pRec);
+  }
+  sqlite3VdbeMemRelease(&m);
+  return SQLITE_OK;
+}
+
+/*
+** This routine sets the value to be returned by subsequent calls to
+** sqlite3_changes() on the database handle 'db'. 
+*/
+void sqlite3VdbeSetChanges(sqlite3 *db, int nChange){
+  assert( sqlite3_mutex_held(db->mutex) );
+  db->nChange = nChange;
+  db->nTotalChange += nChange;
+}
+
+/*
+** Set a flag in the vdbe to update the change counter when it is finalised
+** or reset.
+*/
+void sqlite3VdbeCountChanges(Vdbe *v){
+  v->changeCntOn = 1;
+}
+
+/*
+** Mark every prepared statement associated with a database connection
+** as expired.
+**
+** An expired statement means that recompilation of the statement is
+** recommend.  Statements expire when things happen that make their
+** programs obsolete.  Removing user-defined functions or collating
+** sequences, or changing an authorization function are the types of
+** things that make prepared statements obsolete.
+*/
+void sqlite3ExpirePreparedStatements(sqlite3 *db){
+  Vdbe *p;
+  for(p = db->pVdbe; p; p=p->pNext){
+    p->expired = 1;
+  }
+}
+
+/*
+** Return the database associated with the Vdbe.
+*/
+sqlite3 *sqlite3VdbeDb(Vdbe *v){
+  return v->db;
+}
diff --git a/third_party/sqlite/src/vdbeblob.c b/third_party/sqlite/src/vdbeblob.c
new file mode 100755
index 0000000..746bfe4
--- /dev/null
+++ b/third_party/sqlite/src/vdbeblob.c
@@ -0,0 +1,348 @@
+/*
+** 2007 May 1
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains code used to implement incremental BLOB I/O.
+**
+** $Id: vdbeblob.c,v 1.25 2008/07/28 19:34:54 drh Exp $
+*/
+
+#include "sqliteInt.h"
+#include "vdbeInt.h"
+
+#ifndef SQLITE_OMIT_INCRBLOB
+
+/*
+** Valid sqlite3_blob* handles point to Incrblob structures.
+*/
+typedef struct Incrblob Incrblob;
+struct Incrblob {
+  int flags;              /* Copy of "flags" passed to sqlite3_blob_open() */
+  int nByte;              /* Size of open blob, in bytes */
+  int iOffset;            /* Byte offset of blob in cursor data */
+  BtCursor *pCsr;         /* Cursor pointing at blob row */
+  sqlite3_stmt *pStmt;    /* Statement holding cursor open */
+  sqlite3 *db;            /* The associated database */
+};
+
+/*
+** Open a blob handle.
+*/
+int sqlite3_blob_open(
+  sqlite3* db,            /* The database connection */
+  const char *zDb,        /* The attached database containing the blob */
+  const char *zTable,     /* The table containing the blob */
+  const char *zColumn,    /* The column containing the blob */
+  sqlite_int64 iRow,      /* The row containing the glob */
+  int flags,              /* True -> read/write access, false -> read-only */
+  sqlite3_blob **ppBlob   /* Handle for accessing the blob returned here */
+){
+  int nAttempt = 0;
+  int iCol;               /* Index of zColumn in row-record */
+
+  /* This VDBE program seeks a btree cursor to the identified 
+  ** db/table/row entry. The reason for using a vdbe program instead
+  ** of writing code to use the b-tree layer directly is that the
+  ** vdbe program will take advantage of the various transaction,
+  ** locking and error handling infrastructure built into the vdbe.
+  **
+  ** After seeking the cursor, the vdbe executes an OP_ResultRow.
+  ** Code external to the Vdbe then "borrows" the b-tree cursor and
+  ** uses it to implement the blob_read(), blob_write() and 
+  ** blob_bytes() functions.
+  **
+  ** The sqlite3_blob_close() function finalizes the vdbe program,
+  ** which closes the b-tree cursor and (possibly) commits the 
+  ** transaction.
+  */
+  static const VdbeOpList openBlob[] = {
+    {OP_Transaction, 0, 0, 0},     /* 0: Start a transaction */
+    {OP_VerifyCookie, 0, 0, 0},    /* 1: Check the schema cookie */
+
+    /* One of the following two instructions is replaced by an
+    ** OP_Noop before exection.
+    */
+    {OP_SetNumColumns, 0, 0, 0},   /* 2: Num cols for cursor */
+    {OP_OpenRead, 0, 0, 0},        /* 3: Open cursor 0 for reading */
+    {OP_SetNumColumns, 0, 0, 0},   /* 4: Num cols for cursor */
+    {OP_OpenWrite, 0, 0, 0},       /* 5: Open cursor 0 for read/write */
+
+    {OP_Variable, 1, 1, 0},        /* 6: Push the rowid to the stack */
+    {OP_NotExists, 0, 10, 1},      /* 7: Seek the cursor */
+    {OP_Column, 0, 0, 1},          /* 8  */
+    {OP_ResultRow, 1, 0, 0},       /* 9  */
+    {OP_Close, 0, 0, 0},           /* 10  */
+    {OP_Halt, 0, 0, 0},            /* 11 */
+  };
+
+  Vdbe *v = 0;
+  int rc = SQLITE_OK;
+  char zErr[128];
+
+  zErr[0] = 0;
+  sqlite3_mutex_enter(db->mutex);
+  do {
+    Parse sParse;
+    Table *pTab;
+
+    memset(&sParse, 0, sizeof(Parse));
+    sParse.db = db;
+
+    if( sqlite3SafetyOn(db) ){
+      sqlite3_mutex_leave(db->mutex);
+      return SQLITE_MISUSE;
+    }
+
+    sqlite3BtreeEnterAll(db);
+    pTab = sqlite3LocateTable(&sParse, 0, zTable, zDb);
+    if( pTab && IsVirtual(pTab) ){
+      pTab = 0;
+      sqlite3ErrorMsg(&sParse, "cannot open virtual table: %s", zTable);
+    }
+#ifndef SQLITE_OMIT_VIEW
+    if( pTab && pTab->pSelect ){
+      pTab = 0;
+      sqlite3ErrorMsg(&sParse, "cannot open view: %s", zTable);
+    }
+#endif
+    if( !pTab ){
+      if( sParse.zErrMsg ){
+        sqlite3_snprintf(sizeof(zErr), zErr, "%s", sParse.zErrMsg);
+      }
+      sqlite3DbFree(db, sParse.zErrMsg);
+      rc = SQLITE_ERROR;
+      (void)sqlite3SafetyOff(db);
+      sqlite3BtreeLeaveAll(db);
+      goto blob_open_out;
+    }
+
+    /* Now search pTab for the exact column. */
+    for(iCol=0; iCol < pTab->nCol; iCol++) {
+      if( sqlite3StrICmp(pTab->aCol[iCol].zName, zColumn)==0 ){
+        break;
+      }
+    }
+    if( iCol==pTab->nCol ){
+      sqlite3_snprintf(sizeof(zErr), zErr, "no such column: \"%s\"", zColumn);
+      rc = SQLITE_ERROR;
+      (void)sqlite3SafetyOff(db);
+      sqlite3BtreeLeaveAll(db);
+      goto blob_open_out;
+    }
+
+    /* If the value is being opened for writing, check that the
+    ** column is not indexed. It is against the rules to open an
+    ** indexed column for writing.
+    */
+    if( flags ){
+      Index *pIdx;
+      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+        int j;
+        for(j=0; j<pIdx->nColumn; j++){
+          if( pIdx->aiColumn[j]==iCol ){
+            sqlite3_snprintf(sizeof(zErr), zErr,
+                             "cannot open indexed column for writing");
+            rc = SQLITE_ERROR;
+            (void)sqlite3SafetyOff(db);
+            sqlite3BtreeLeaveAll(db);
+            goto blob_open_out;
+          }
+        }
+      }
+    }
+
+    v = sqlite3VdbeCreate(db);
+    if( v ){
+      int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+      sqlite3VdbeAddOpList(v, sizeof(openBlob)/sizeof(VdbeOpList), openBlob);
+
+      /* Configure the OP_Transaction */
+      sqlite3VdbeChangeP1(v, 0, iDb);
+      sqlite3VdbeChangeP2(v, 0, (flags ? 1 : 0));
+
+      /* Configure the OP_VerifyCookie */
+      sqlite3VdbeChangeP1(v, 1, iDb);
+      sqlite3VdbeChangeP2(v, 1, pTab->pSchema->schema_cookie);
+
+      /* Make sure a mutex is held on the table to be accessed */
+      sqlite3VdbeUsesBtree(v, iDb); 
+
+      /* Remove either the OP_OpenWrite or OpenRead. Set the P2 
+      ** parameter of the other to pTab->tnum. 
+      */
+      sqlite3VdbeChangeToNoop(v, (flags ? 3 : 5), 1);
+      sqlite3VdbeChangeP2(v, (flags ? 5 : 3), pTab->tnum);
+      sqlite3VdbeChangeP3(v, (flags ? 5 : 3), iDb);
+
+      /* Configure the OP_SetNumColumns. Configure the cursor to
+      ** think that the table has one more column than it really
+      ** does. An OP_Column to retrieve this imaginary column will
+      ** always return an SQL NULL. This is useful because it means
+      ** we can invoke OP_Column to fill in the vdbe cursors type 
+      ** and offset cache without causing any IO.
+      */
+      sqlite3VdbeChangeP2(v, flags ? 4 : 2, pTab->nCol+1);
+      sqlite3VdbeChangeP2(v, 8, pTab->nCol);
+      if( !db->mallocFailed ){
+        sqlite3VdbeMakeReady(v, 1, 1, 1, 0);
+      }
+    }
+   
+    sqlite3BtreeLeaveAll(db);
+    rc = sqlite3SafetyOff(db);
+    if( rc!=SQLITE_OK || db->mallocFailed ){
+      goto blob_open_out;
+    }
+
+    sqlite3_bind_int64((sqlite3_stmt *)v, 1, iRow);
+    rc = sqlite3_step((sqlite3_stmt *)v);
+    if( rc!=SQLITE_ROW ){
+      nAttempt++;
+      rc = sqlite3_finalize((sqlite3_stmt *)v);
+      sqlite3_snprintf(sizeof(zErr), zErr, sqlite3_errmsg(db));
+      v = 0;
+    }
+  } while( nAttempt<5 && rc==SQLITE_SCHEMA );
+
+  if( rc==SQLITE_ROW ){
+    /* The row-record has been opened successfully. Check that the
+    ** column in question contains text or a blob. If it contains
+    ** text, it is up to the caller to get the encoding right.
+    */
+    Incrblob *pBlob;
+    u32 type = v->apCsr[0]->aType[iCol];
+
+    if( type<12 ){
+      sqlite3_snprintf(sizeof(zErr), zErr, "cannot open value of type %s",
+          type==0?"null": type==7?"real": "integer"
+      );
+      rc = SQLITE_ERROR;
+      goto blob_open_out;
+    }
+    pBlob = (Incrblob *)sqlite3DbMallocZero(db, sizeof(Incrblob));
+    if( db->mallocFailed ){
+      sqlite3DbFree(db, pBlob);
+      goto blob_open_out;
+    }
+    pBlob->flags = flags;
+    pBlob->pCsr =  v->apCsr[0]->pCursor;
+    sqlite3BtreeEnterCursor(pBlob->pCsr);
+    sqlite3BtreeCacheOverflow(pBlob->pCsr);
+    sqlite3BtreeLeaveCursor(pBlob->pCsr);
+    pBlob->pStmt = (sqlite3_stmt *)v;
+    pBlob->iOffset = v->apCsr[0]->aOffset[iCol];
+    pBlob->nByte = sqlite3VdbeSerialTypeLen(type);
+    pBlob->db = db;
+    *ppBlob = (sqlite3_blob *)pBlob;
+    rc = SQLITE_OK;
+  }else if( rc==SQLITE_OK ){
+    sqlite3_snprintf(sizeof(zErr), zErr, "no such rowid: %lld", iRow);
+    rc = SQLITE_ERROR;
+  }
+
+blob_open_out:
+  zErr[sizeof(zErr)-1] = '\0';
+  if( rc!=SQLITE_OK || db->mallocFailed ){
+    sqlite3_finalize((sqlite3_stmt *)v);
+  }
+  sqlite3Error(db, rc, (rc==SQLITE_OK?0:zErr));
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Close a blob handle that was previously created using
+** sqlite3_blob_open().
+*/
+int sqlite3_blob_close(sqlite3_blob *pBlob){
+  Incrblob *p = (Incrblob *)pBlob;
+  int rc;
+
+  rc = sqlite3_finalize(p->pStmt);
+  sqlite3DbFree(p->db, p);
+  return rc;
+}
+
+/*
+** Perform a read or write operation on a blob
+*/
+static int blobReadWrite(
+  sqlite3_blob *pBlob, 
+  void *z, 
+  int n, 
+  int iOffset, 
+  int (*xCall)(BtCursor*, u32, u32, void*)
+){
+  int rc;
+  Incrblob *p = (Incrblob *)pBlob;
+  Vdbe *v;
+  sqlite3 *db = p->db;  
+
+  /* Request is out of range. Return a transient error. */
+  if( (iOffset+n)>p->nByte ){
+    return SQLITE_ERROR;
+  }
+  sqlite3_mutex_enter(db->mutex);
+
+  /* If there is no statement handle, then the blob-handle has
+  ** already been invalidated. Return SQLITE_ABORT in this case.
+  */
+  v = (Vdbe*)p->pStmt;
+  if( v==0 ){
+    rc = SQLITE_ABORT;
+  }else{
+    /* Call either BtreeData() or BtreePutData(). If SQLITE_ABORT is
+    ** returned, clean-up the statement handle.
+    */
+    assert( db == v->db );
+    sqlite3BtreeEnterCursor(p->pCsr);
+    rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);
+    sqlite3BtreeLeaveCursor(p->pCsr);
+    if( rc==SQLITE_ABORT ){
+      sqlite3VdbeFinalize(v);
+      p->pStmt = 0;
+    }else{
+      db->errCode = rc;
+      v->rc = rc;
+    }
+  }
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Read data from a blob handle.
+*/
+int sqlite3_blob_read(sqlite3_blob *pBlob, void *z, int n, int iOffset){
+  return blobReadWrite(pBlob, z, n, iOffset, sqlite3BtreeData);
+}
+
+/*
+** Write data to a blob handle.
+*/
+int sqlite3_blob_write(sqlite3_blob *pBlob, const void *z, int n, int iOffset){
+  return blobReadWrite(pBlob, (void *)z, n, iOffset, sqlite3BtreePutData);
+}
+
+/*
+** Query a blob handle for the size of the data.
+**
+** The Incrblob.nByte field is fixed for the lifetime of the Incrblob
+** so no mutex is required for access.
+*/
+int sqlite3_blob_bytes(sqlite3_blob *pBlob){
+  Incrblob *p = (Incrblob *)pBlob;
+  return p->nByte;
+}
+
+#endif /* #ifndef SQLITE_OMIT_INCRBLOB */
diff --git a/third_party/sqlite/src/vdbefifo.c b/third_party/sqlite/src/vdbefifo.c
new file mode 100755
index 0000000..a5e270d
--- /dev/null
+++ b/third_party/sqlite/src/vdbefifo.c
@@ -0,0 +1,130 @@
+/*
+** 2005 June 16
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file implements a FIFO queue of rowids used for processing
+** UPDATE and DELETE statements.
+**
+** $Id: vdbefifo.c,v 1.8 2008/07/28 19:34:54 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "vdbeInt.h"
+
+/*
+** Constants FIFOSIZE_FIRST and FIFOSIZE_MAX are the initial
+** number of entries in a fifo page and the maximum number of
+** entries in a fifo page.
+*/
+#define FIFOSIZE_FIRST (((128-sizeof(FifoPage))/8)+1)
+#ifdef SQLITE_MALLOC_SOFT_LIMIT
+# define FIFOSIZE_MAX   (((SQLITE_MALLOC_SOFT_LIMIT-sizeof(FifoPage))/8)+1)
+#else
+# define FIFOSIZE_MAX   (((262144-sizeof(FifoPage))/8)+1)
+#endif
+
+/*
+** Allocate a new FifoPage and return a pointer to it.  Return NULL if
+** we run out of memory.  Leave space on the page for nEntry entries.
+*/
+static FifoPage *allocateFifoPage(sqlite3 *db, int nEntry){
+  FifoPage *pPage;
+  if( nEntry>FIFOSIZE_MAX ){
+    nEntry = FIFOSIZE_MAX;
+  }
+  pPage = sqlite3DbMallocRaw(db, sizeof(FifoPage) + sizeof(i64)*(nEntry-1) );
+  if( pPage ){
+    pPage->nSlot = nEntry;
+    pPage->iWrite = 0;
+    pPage->iRead = 0;
+    pPage->pNext = 0;
+  }
+  return pPage;
+}
+
+/*
+** Initialize a Fifo structure.
+*/
+void sqlite3VdbeFifoInit(Fifo *pFifo, sqlite3 *db){
+  memset(pFifo, 0, sizeof(*pFifo));
+  pFifo->db = db;
+}
+
+/*
+** Push a single 64-bit integer value into the Fifo.  Return SQLITE_OK
+** normally.   SQLITE_NOMEM is returned if we are unable to allocate
+** memory.
+*/
+int sqlite3VdbeFifoPush(Fifo *pFifo, i64 val){
+  FifoPage *pPage;
+  pPage = pFifo->pLast;
+  if( pPage==0 ){
+    pPage = pFifo->pLast = pFifo->pFirst =
+         allocateFifoPage(pFifo->db, FIFOSIZE_FIRST);
+    if( pPage==0 ){
+      return SQLITE_NOMEM;
+    }
+  }else if( pPage->iWrite>=pPage->nSlot ){
+    pPage->pNext = allocateFifoPage(pFifo->db, pFifo->nEntry);
+    if( pPage->pNext==0 ){
+      return SQLITE_NOMEM;
+    }
+    pPage = pFifo->pLast = pPage->pNext;
+  }
+  pPage->aSlot[pPage->iWrite++] = val;
+  pFifo->nEntry++;
+  return SQLITE_OK;
+}
+
+/*
+** Extract a single 64-bit integer value from the Fifo.  The integer
+** extracted is the one least recently inserted.  If the Fifo is empty
+** return SQLITE_DONE.
+*/
+int sqlite3VdbeFifoPop(Fifo *pFifo, i64 *pVal){
+  FifoPage *pPage;
+  if( pFifo->nEntry==0 ){
+    return SQLITE_DONE;
+  }
+  assert( pFifo->nEntry>0 );
+  pPage = pFifo->pFirst;
+  assert( pPage!=0 );
+  assert( pPage->iWrite>pPage->iRead );
+  assert( pPage->iWrite<=pPage->nSlot );
+  assert( pPage->iRead<pPage->nSlot );
+  assert( pPage->iRead>=0 );
+  *pVal = pPage->aSlot[pPage->iRead++];
+  pFifo->nEntry--;
+  if( pPage->iRead>=pPage->iWrite ){
+    pFifo->pFirst = pPage->pNext;
+    sqlite3DbFree(pFifo->db, pPage);
+    if( pFifo->nEntry==0 ){
+      assert( pFifo->pLast==pPage );
+      pFifo->pLast = 0;
+    }else{
+      assert( pFifo->pFirst!=0 );
+    }
+  }else{
+    assert( pFifo->nEntry>0 );
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Delete all information from a Fifo object.   Free all memory held
+** by the Fifo.
+*/
+void sqlite3VdbeFifoClear(Fifo *pFifo){
+  FifoPage *pPage, *pNextPage;
+  for(pPage=pFifo->pFirst; pPage; pPage=pNextPage){
+    pNextPage = pPage->pNext;
+    sqlite3DbFree(pFifo->db, pPage);
+  }
+  sqlite3VdbeFifoInit(pFifo, pFifo->db);
+}
diff --git a/third_party/sqlite/src/vdbemem.c b/third_party/sqlite/src/vdbemem.c
new file mode 100755
index 0000000..8b94e3e
--- /dev/null
+++ b/third_party/sqlite/src/vdbemem.c
@@ -0,0 +1,1044 @@
+/*
+** 2004 May 26
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains code use to manipulate "Mem" structure.  A "Mem"
+** stores a single value in the VDBE.  Mem is an opaque structure visible
+** only within the VDBE.  Interface routines refer to a Mem using the
+** name sqlite_value
+**
+** $Id: vdbemem.c,v 1.121 2008/08/01 20:10:09 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+#include "vdbeInt.h"
+
+/*
+** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
+** P if required.
+*/
+#define expandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
+
+/*
+** If pMem is an object with a valid string representation, this routine
+** ensures the internal encoding for the string representation is
+** 'desiredEnc', one of SQLITE_UTF8, SQLITE_UTF16LE or SQLITE_UTF16BE.
+**
+** If pMem is not a string object, or the encoding of the string
+** representation is already stored using the requested encoding, then this
+** routine is a no-op.
+**
+** SQLITE_OK is returned if the conversion is successful (or not required).
+** SQLITE_NOMEM may be returned if a malloc() fails during conversion
+** between formats.
+*/
+int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
+  int rc;
+  if( !(pMem->flags&MEM_Str) || pMem->enc==desiredEnc ){
+    return SQLITE_OK;
+  }
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+#ifdef SQLITE_OMIT_UTF16
+  return SQLITE_ERROR;
+#else
+
+  /* MemTranslate() may return SQLITE_OK or SQLITE_NOMEM. If NOMEM is returned,
+  ** then the encoding of the value may not have changed.
+  */
+  rc = sqlite3VdbeMemTranslate(pMem, desiredEnc);
+  assert(rc==SQLITE_OK    || rc==SQLITE_NOMEM);
+  assert(rc==SQLITE_OK    || pMem->enc!=desiredEnc);
+  assert(rc==SQLITE_NOMEM || pMem->enc==desiredEnc);
+  return rc;
+#endif
+}
+
+/*
+** Make sure pMem->z points to a writable allocation of at least 
+** n bytes.
+**
+** If the memory cell currently contains string or blob data
+** and the third argument passed to this function is true, the 
+** current content of the cell is preserved. Otherwise, it may
+** be discarded.  
+**
+** This function sets the MEM_Dyn flag and clears any xDel callback.
+** It also clears MEM_Ephem and MEM_Static. If the preserve flag is 
+** not set, Mem.n is zeroed.
+*/
+int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve){
+  assert( 1 >=
+    ((pMem->zMalloc && pMem->zMalloc==pMem->z) ? 1 : 0) +
+    (((pMem->flags&MEM_Dyn)&&pMem->xDel) ? 1 : 0) + 
+    ((pMem->flags&MEM_Ephem) ? 1 : 0) + 
+    ((pMem->flags&MEM_Static) ? 1 : 0)
+  );
+
+  if( n<32 ) n = 32;
+  if( sqlite3DbMallocSize(pMem->db, pMem->zMalloc)<n ){
+    if( preserve && pMem->z==pMem->zMalloc ){
+      pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
+      if( !pMem->z ){
+        pMem->flags = MEM_Null;
+      }
+      preserve = 0;
+    }else{
+      sqlite3DbFree(pMem->db, pMem->zMalloc);
+      pMem->zMalloc = sqlite3DbMallocRaw(pMem->db, n);
+    }
+  }
+
+  if( preserve && pMem->z && pMem->zMalloc && pMem->z!=pMem->zMalloc ){
+    memcpy(pMem->zMalloc, pMem->z, pMem->n);
+  }
+  if( pMem->flags&MEM_Dyn && pMem->xDel ){
+    pMem->xDel((void *)(pMem->z));
+  }
+
+  pMem->z = pMem->zMalloc;
+  pMem->flags &= ~(MEM_Ephem|MEM_Static);
+  pMem->xDel = 0;
+  return (pMem->z ? SQLITE_OK : SQLITE_NOMEM);
+}
+
+/*
+** Make the given Mem object MEM_Dyn.  In other words, make it so
+** that any TEXT or BLOB content is stored in memory obtained from
+** malloc().  In this way, we know that the memory is safe to be
+** overwritten or altered.
+**
+** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
+*/
+int sqlite3VdbeMemMakeWriteable(Mem *pMem){
+  int f;
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  expandBlob(pMem);
+  f = pMem->flags;
+  if( (f&(MEM_Str|MEM_Blob)) && pMem->z!=pMem->zMalloc ){
+    if( sqlite3VdbeMemGrow(pMem, pMem->n + 2, 1) ){
+      return SQLITE_NOMEM;
+    }
+    pMem->z[pMem->n] = 0;
+    pMem->z[pMem->n+1] = 0;
+    pMem->flags |= MEM_Term;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** If the given Mem* has a zero-filled tail, turn it into an ordinary
+** blob stored in dynamically allocated space.
+*/
+#ifndef SQLITE_OMIT_INCRBLOB
+int sqlite3VdbeMemExpandBlob(Mem *pMem){
+  if( pMem->flags & MEM_Zero ){
+    int nByte;
+    assert( pMem->flags&MEM_Blob );
+    assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+
+    /* Set nByte to the number of bytes required to store the expanded blob. */
+    nByte = pMem->n + pMem->u.i;
+    if( nByte<=0 ){
+      nByte = 1;
+    }
+    if( sqlite3VdbeMemGrow(pMem, nByte, 1) ){
+      return SQLITE_NOMEM;
+    }
+
+    memset(&pMem->z[pMem->n], 0, pMem->u.i);
+    pMem->n += pMem->u.i;
+    pMem->flags &= ~(MEM_Zero|MEM_Term);
+  }
+  return SQLITE_OK;
+}
+#endif
+
+
+/*
+** Make sure the given Mem is \u0000 terminated.
+*/
+int sqlite3VdbeMemNulTerminate(Mem *pMem){
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  if( (pMem->flags & MEM_Term)!=0 || (pMem->flags & MEM_Str)==0 ){
+    return SQLITE_OK;   /* Nothing to do */
+  }
+  if( sqlite3VdbeMemGrow(pMem, pMem->n+2, 1) ){
+    return SQLITE_NOMEM;
+  }
+  pMem->z[pMem->n] = 0;
+  pMem->z[pMem->n+1] = 0;
+  pMem->flags |= MEM_Term;
+  return SQLITE_OK;
+}
+
+/*
+** Add MEM_Str to the set of representations for the given Mem.  Numbers
+** are converted using sqlite3_snprintf().  Converting a BLOB to a string
+** is a no-op.
+**
+** Existing representations MEM_Int and MEM_Real are *not* invalidated.
+**
+** A MEM_Null value will never be passed to this function. This function is
+** used for converting values to text for returning to the user (i.e. via
+** sqlite3_value_text()), or for ensuring that values to be used as btree
+** keys are strings. In the former case a NULL pointer is returned the
+** user and the later is an internal programming error.
+*/
+int sqlite3VdbeMemStringify(Mem *pMem, int enc){
+  int rc = SQLITE_OK;
+  int fg = pMem->flags;
+  const int nByte = 32;
+
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  assert( !(fg&MEM_Zero) );
+  assert( !(fg&(MEM_Str|MEM_Blob)) );
+  assert( fg&(MEM_Int|MEM_Real) );
+
+  if( sqlite3VdbeMemGrow(pMem, nByte, 0) ){
+    return SQLITE_NOMEM;
+  }
+
+  /* For a Real or Integer, use sqlite3_mprintf() to produce the UTF-8
+  ** string representation of the value. Then, if the required encoding
+  ** is UTF-16le or UTF-16be do a translation.
+  ** 
+  ** FIX ME: It would be better if sqlite3_snprintf() could do UTF-16.
+  */
+  if( fg & MEM_Int ){
+    sqlite3_snprintf(nByte, pMem->z, "%lld", pMem->u.i);
+  }else{
+    assert( fg & MEM_Real );
+    sqlite3_snprintf(nByte, pMem->z, "%!.15g", pMem->r);
+  }
+  pMem->n = strlen(pMem->z);
+  pMem->enc = SQLITE_UTF8;
+  pMem->flags |= MEM_Str|MEM_Term;
+  sqlite3VdbeChangeEncoding(pMem, enc);
+  return rc;
+}
+
+/*
+** Memory cell pMem contains the context of an aggregate function.
+** This routine calls the finalize method for that function.  The
+** result of the aggregate is stored back into pMem.
+**
+** Return SQLITE_ERROR if the finalizer reports an error.  SQLITE_OK
+** otherwise.
+*/
+int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){
+  int rc = SQLITE_OK;
+  if( pFunc && pFunc->xFinalize ){
+    sqlite3_context ctx;
+    assert( (pMem->flags & MEM_Null)!=0 || pFunc==pMem->u.pDef );
+    assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+    ctx.s.flags = MEM_Null;
+    ctx.s.db = pMem->db;
+    ctx.s.zMalloc = 0;
+    ctx.pMem = pMem;
+    ctx.pFunc = pFunc;
+    ctx.isError = 0;
+    pFunc->xFinalize(&ctx);
+    assert( 0==(pMem->flags&MEM_Dyn) && !pMem->xDel );
+    sqlite3DbFree(pMem->db, pMem->zMalloc);
+    *pMem = ctx.s;
+    rc = (ctx.isError?SQLITE_ERROR:SQLITE_OK);
+  }
+  return rc;
+}
+
+/*
+** If the memory cell contains a string value that must be freed by
+** invoking an external callback, free it now. Calling this function
+** does not free any Mem.zMalloc buffer.
+*/
+void sqlite3VdbeMemReleaseExternal(Mem *p){
+  assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
+  if( p->flags&MEM_Agg ){
+    sqlite3VdbeMemFinalize(p, p->u.pDef);
+    assert( (p->flags & MEM_Agg)==0 );
+    sqlite3VdbeMemRelease(p);
+  }else if( p->flags&MEM_Dyn && p->xDel ){
+    p->xDel((void *)p->z);
+    p->xDel = 0;
+  }
+}
+
+/*
+** Release any memory held by the Mem. This may leave the Mem in an
+** inconsistent state, for example with (Mem.z==0) and
+** (Mem.type==SQLITE_TEXT).
+*/
+void sqlite3VdbeMemRelease(Mem *p){
+  sqlite3VdbeMemReleaseExternal(p);
+  sqlite3DbFree(p->db, p->zMalloc);
+  p->z = 0;
+  p->zMalloc = 0;
+  p->xDel = 0;
+}
+
+/*
+** Convert a 64-bit IEEE double into a 64-bit signed integer.
+** If the double is too large, return 0x8000000000000000.
+**
+** Most systems appear to do this simply by assigning
+** variables and without the extra range tests.  But
+** there are reports that windows throws an expection
+** if the floating point value is out of range. (See ticket #2880.)
+** Because we do not completely understand the problem, we will
+** take the conservative approach and always do range tests
+** before attempting the conversion.
+*/
+static i64 doubleToInt64(double r){
+  /*
+  ** Many compilers we encounter do not define constants for the
+  ** minimum and maximum 64-bit integers, or they define them
+  ** inconsistently.  And many do not understand the "LL" notation.
+  ** So we define our own static constants here using nothing
+  ** larger than a 32-bit integer constant.
+  */
+  static const i64 maxInt = LARGEST_INT64;
+  static const i64 minInt = SMALLEST_INT64;
+
+  if( r<(double)minInt ){
+    return minInt;
+  }else if( r>(double)maxInt ){
+    return minInt;
+  }else{
+    return (i64)r;
+  }
+}
+
+/*
+** Return some kind of integer value which is the best we can do
+** at representing the value that *pMem describes as an integer.
+** If pMem is an integer, then the value is exact.  If pMem is
+** a floating-point then the value returned is the integer part.
+** If pMem is a string or blob, then we make an attempt to convert
+** it into a integer and return that.  If pMem is NULL, return 0.
+**
+** If pMem is a string, its encoding might be changed.
+*/
+i64 sqlite3VdbeIntValue(Mem *pMem){
+  int flags;
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  flags = pMem->flags;
+  if( flags & MEM_Int ){
+    return pMem->u.i;
+  }else if( flags & MEM_Real ){
+    return doubleToInt64(pMem->r);
+  }else if( flags & (MEM_Str|MEM_Blob) ){
+    i64 value;
+    pMem->flags |= MEM_Str;
+    if( sqlite3VdbeChangeEncoding(pMem, SQLITE_UTF8)
+       || sqlite3VdbeMemNulTerminate(pMem) ){
+      return 0;
+    }
+    assert( pMem->z );
+    sqlite3Atoi64(pMem->z, &value);
+    return value;
+  }else{
+    return 0;
+  }
+}
+
+/*
+** Return the best representation of pMem that we can get into a
+** double.  If pMem is already a double or an integer, return its
+** value.  If it is a string or blob, try to convert it to a double.
+** If it is a NULL, return 0.0.
+*/
+double sqlite3VdbeRealValue(Mem *pMem){
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  if( pMem->flags & MEM_Real ){
+    return pMem->r;
+  }else if( pMem->flags & MEM_Int ){
+    return (double)pMem->u.i;
+  }else if( pMem->flags & (MEM_Str|MEM_Blob) ){
+    double val = 0.0;
+    pMem->flags |= MEM_Str;
+    if( sqlite3VdbeChangeEncoding(pMem, SQLITE_UTF8)
+       || sqlite3VdbeMemNulTerminate(pMem) ){
+      return 0.0;
+    }
+    assert( pMem->z );
+    sqlite3AtoF(pMem->z, &val);
+    return val;
+  }else{
+    return 0.0;
+  }
+}
+
+/*
+** The MEM structure is already a MEM_Real.  Try to also make it a
+** MEM_Int if we can.
+*/
+void sqlite3VdbeIntegerAffinity(Mem *pMem){
+  assert( pMem->flags & MEM_Real );
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+
+  pMem->u.i = doubleToInt64(pMem->r);
+  if( pMem->r==(double)pMem->u.i ){
+    pMem->flags |= MEM_Int;
+  }
+}
+
+static void setTypeFlag(Mem *pMem, int f){
+  MemSetTypeFlag(pMem, f);
+}
+
+/*
+** Convert pMem to type integer.  Invalidate any prior representations.
+*/
+int sqlite3VdbeMemIntegerify(Mem *pMem){
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  pMem->u.i = sqlite3VdbeIntValue(pMem);
+  setTypeFlag(pMem, MEM_Int);
+  return SQLITE_OK;
+}
+
+/*
+** Convert pMem so that it is of type MEM_Real.
+** Invalidate any prior representations.
+*/
+int sqlite3VdbeMemRealify(Mem *pMem){
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  pMem->r = sqlite3VdbeRealValue(pMem);
+  setTypeFlag(pMem, MEM_Real);
+  return SQLITE_OK;
+}
+
+/*
+** Convert pMem so that it has types MEM_Real or MEM_Int or both.
+** Invalidate any prior representations.
+*/
+int sqlite3VdbeMemNumerify(Mem *pMem){
+  double r1, r2;
+  i64 i;
+  assert( (pMem->flags & (MEM_Int|MEM_Real|MEM_Null))==0 );
+  assert( (pMem->flags & (MEM_Blob|MEM_Str))!=0 );
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  r1 = sqlite3VdbeRealValue(pMem);
+  i = doubleToInt64(r1);
+  r2 = (double)i;
+  if( r1==r2 ){
+    sqlite3VdbeMemIntegerify(pMem);
+  }else{
+    pMem->r = r1;
+    setTypeFlag(pMem, MEM_Real);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Delete any previous value and set the value stored in *pMem to NULL.
+*/
+void sqlite3VdbeMemSetNull(Mem *pMem){
+  setTypeFlag(pMem, MEM_Null);
+  pMem->type = SQLITE_NULL;
+}
+
+/*
+** Delete any previous value and set the value to be a BLOB of length
+** n containing all zeros.
+*/
+void sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){
+  sqlite3VdbeMemRelease(pMem);
+  setTypeFlag(pMem, MEM_Blob);
+  pMem->flags = MEM_Blob|MEM_Zero;
+  pMem->type = SQLITE_BLOB;
+  pMem->n = 0;
+  if( n<0 ) n = 0;
+  pMem->u.i = n;
+  pMem->enc = SQLITE_UTF8;
+}
+
+/*
+** Delete any previous value and set the value stored in *pMem to val,
+** manifest type INTEGER.
+*/
+void sqlite3VdbeMemSetInt64(Mem *pMem, i64 val){
+  sqlite3VdbeMemRelease(pMem);
+  pMem->u.i = val;
+  pMem->flags = MEM_Int;
+  pMem->type = SQLITE_INTEGER;
+}
+
+/*
+** Delete any previous value and set the value stored in *pMem to val,
+** manifest type REAL.
+*/
+void sqlite3VdbeMemSetDouble(Mem *pMem, double val){
+  if( sqlite3IsNaN(val) ){
+    sqlite3VdbeMemSetNull(pMem);
+  }else{
+    sqlite3VdbeMemRelease(pMem);
+    pMem->r = val;
+    pMem->flags = MEM_Real;
+    pMem->type = SQLITE_FLOAT;
+  }
+}
+
+/*
+** Return true if the Mem object contains a TEXT or BLOB that is
+** too large - whose size exceeds SQLITE_MAX_LENGTH.
+*/
+int sqlite3VdbeMemTooBig(Mem *p){
+  assert( p->db!=0 );
+  if( p->flags & (MEM_Str|MEM_Blob) ){
+    int n = p->n;
+    if( p->flags & MEM_Zero ){
+      n += p->u.i;
+    }
+    return n>p->db->aLimit[SQLITE_LIMIT_LENGTH];
+  }
+  return 0; 
+}
+
+/*
+** Size of struct Mem not including the Mem.zMalloc member.
+*/
+#define MEMCELLSIZE (size_t)(&(((Mem *)0)->zMalloc))
+
+/*
+** Make an shallow copy of pFrom into pTo.  Prior contents of
+** pTo are freed.  The pFrom->z field is not duplicated.  If
+** pFrom->z is used, then pTo->z points to the same thing as pFrom->z
+** and flags gets srcType (either MEM_Ephem or MEM_Static).
+*/
+void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
+  sqlite3VdbeMemReleaseExternal(pTo);
+  memcpy(pTo, pFrom, MEMCELLSIZE);
+  pTo->xDel = 0;
+  if( (pFrom->flags&MEM_Dyn)!=0 || pFrom->z==pFrom->zMalloc ){
+    pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);
+    assert( srcType==MEM_Ephem || srcType==MEM_Static );
+    pTo->flags |= srcType;
+  }
+}
+
+/*
+** Make a full copy of pFrom into pTo.  Prior contents of pTo are
+** freed before the copy is made.
+*/
+int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
+  int rc = SQLITE_OK;
+
+  sqlite3VdbeMemReleaseExternal(pTo);
+  memcpy(pTo, pFrom, MEMCELLSIZE);
+  pTo->flags &= ~MEM_Dyn;
+
+  if( pTo->flags&(MEM_Str|MEM_Blob) ){
+    if( 0==(pFrom->flags&MEM_Static) ){
+      pTo->flags |= MEM_Ephem;
+      rc = sqlite3VdbeMemMakeWriteable(pTo);
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Transfer the contents of pFrom to pTo. Any existing value in pTo is
+** freed. If pFrom contains ephemeral data, a copy is made.
+**
+** pFrom contains an SQL NULL when this routine returns.
+*/
+void sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom){
+  assert( pFrom->db==0 || sqlite3_mutex_held(pFrom->db->mutex) );
+  assert( pTo->db==0 || sqlite3_mutex_held(pTo->db->mutex) );
+  assert( pFrom->db==0 || pTo->db==0 || pFrom->db==pTo->db );
+
+  sqlite3VdbeMemRelease(pTo);
+  memcpy(pTo, pFrom, sizeof(Mem));
+  pFrom->flags = MEM_Null;
+  pFrom->xDel = 0;
+  pFrom->zMalloc = 0;
+}
+
+/*
+** Change the value of a Mem to be a string or a BLOB.
+**
+** The memory management strategy depends on the value of the xDel
+** parameter. If the value passed is SQLITE_TRANSIENT, then the 
+** string is copied into a (possibly existing) buffer managed by the 
+** Mem structure. Otherwise, any existing buffer is freed and the
+** pointer copied.
+*/
+int sqlite3VdbeMemSetStr(
+  Mem *pMem,          /* Memory cell to set to string value */
+  const char *z,      /* String pointer */
+  int n,              /* Bytes in string, or negative */
+  u8 enc,             /* Encoding of z.  0 for BLOBs */
+  void (*xDel)(void*) /* Destructor function */
+){
+  int nByte = n;      /* New value for pMem->n */
+  int iLimit;         /* Maximum allowed string or blob size */
+  int flags = 0;      /* New value for pMem->flags */
+
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+
+  /* If z is a NULL pointer, set pMem to contain an SQL NULL. */
+  if( !z ){
+    sqlite3VdbeMemSetNull(pMem);
+    return SQLITE_OK;
+  }
+
+  if( pMem->db ){
+    iLimit = pMem->db->aLimit[SQLITE_LIMIT_LENGTH];
+  }else{
+    iLimit = SQLITE_MAX_LENGTH;
+  }
+  flags = (enc==0?MEM_Blob:MEM_Str);
+  if( nByte<0 ){
+    assert( enc!=0 );
+    if( enc==SQLITE_UTF8 ){
+      for(nByte=0; nByte<=iLimit && z[nByte]; nByte++){}
+    }else{
+      for(nByte=0; nByte<=iLimit && (z[nByte] | z[nByte+1]); nByte+=2){}
+    }
+    flags |= MEM_Term;
+  }
+  if( nByte>iLimit ){
+    return SQLITE_TOOBIG;
+  }
+
+  /* The following block sets the new values of Mem.z and Mem.xDel. It
+  ** also sets a flag in local variable "flags" to indicate the memory
+  ** management (one of MEM_Dyn or MEM_Static).
+  */
+  if( xDel==SQLITE_TRANSIENT ){
+    int nAlloc = nByte;
+    if( flags&MEM_Term ){
+      nAlloc += (enc==SQLITE_UTF8?1:2);
+    }
+    if( sqlite3VdbeMemGrow(pMem, nAlloc, 0) ){
+      return SQLITE_NOMEM;
+    }
+    memcpy(pMem->z, z, nAlloc);
+  }else if( xDel==SQLITE_DYNAMIC ){
+    sqlite3VdbeMemRelease(pMem);
+    pMem->zMalloc = pMem->z = (char *)z;
+    pMem->xDel = 0;
+  }else{
+    sqlite3VdbeMemRelease(pMem);
+    pMem->z = (char *)z;
+    pMem->xDel = xDel;
+    flags |= ((xDel==SQLITE_STATIC)?MEM_Static:MEM_Dyn);
+  }
+
+  pMem->n = nByte;
+  pMem->flags = flags;
+  pMem->enc = (enc==0 ? SQLITE_UTF8 : enc);
+  pMem->type = (enc==0 ? SQLITE_BLOB : SQLITE_TEXT);
+
+#ifndef SQLITE_OMIT_UTF16
+  if( pMem->enc!=SQLITE_UTF8 && sqlite3VdbeMemHandleBom(pMem) ){
+    return SQLITE_NOMEM;
+  }
+#endif
+
+  return SQLITE_OK;
+}
+
+/*
+** Compare the values contained by the two memory cells, returning
+** negative, zero or positive if pMem1 is less than, equal to, or greater
+** than pMem2. Sorting order is NULL's first, followed by numbers (integers
+** and reals) sorted numerically, followed by text ordered by the collating
+** sequence pColl and finally blob's ordered by memcmp().
+**
+** Two NULL values are considered equal by this function.
+*/
+int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const CollSeq *pColl){
+  int rc;
+  int f1, f2;
+  int combined_flags;
+
+  /* Interchange pMem1 and pMem2 if the collating sequence specifies
+  ** DESC order.
+  */
+  f1 = pMem1->flags;
+  f2 = pMem2->flags;
+  combined_flags = f1|f2;
+ 
+  /* If one value is NULL, it is less than the other. If both values
+  ** are NULL, return 0.
+  */
+  if( combined_flags&MEM_Null ){
+    return (f2&MEM_Null) - (f1&MEM_Null);
+  }
+
+  /* If one value is a number and the other is not, the number is less.
+  ** If both are numbers, compare as reals if one is a real, or as integers
+  ** if both values are integers.
+  */
+  if( combined_flags&(MEM_Int|MEM_Real) ){
+    if( !(f1&(MEM_Int|MEM_Real)) ){
+      return 1;
+    }
+    if( !(f2&(MEM_Int|MEM_Real)) ){
+      return -1;
+    }
+    if( (f1 & f2 & MEM_Int)==0 ){
+      double r1, r2;
+      if( (f1&MEM_Real)==0 ){
+        r1 = pMem1->u.i;
+      }else{
+        r1 = pMem1->r;
+      }
+      if( (f2&MEM_Real)==0 ){
+        r2 = pMem2->u.i;
+      }else{
+        r2 = pMem2->r;
+      }
+      if( r1<r2 ) return -1;
+      if( r1>r2 ) return 1;
+      return 0;
+    }else{
+      assert( f1&MEM_Int );
+      assert( f2&MEM_Int );
+      if( pMem1->u.i < pMem2->u.i ) return -1;
+      if( pMem1->u.i > pMem2->u.i ) return 1;
+      return 0;
+    }
+  }
+
+  /* If one value is a string and the other is a blob, the string is less.
+  ** If both are strings, compare using the collating functions.
+  */
+  if( combined_flags&MEM_Str ){
+    if( (f1 & MEM_Str)==0 ){
+      return 1;
+    }
+    if( (f2 & MEM_Str)==0 ){
+      return -1;
+    }
+
+    assert( pMem1->enc==pMem2->enc );
+    assert( pMem1->enc==SQLITE_UTF8 || 
+            pMem1->enc==SQLITE_UTF16LE || pMem1->enc==SQLITE_UTF16BE );
+
+    /* The collation sequence must be defined at this point, even if
+    ** the user deletes the collation sequence after the vdbe program is
+    ** compiled (this was not always the case).
+    */
+    assert( !pColl || pColl->xCmp );
+
+    if( pColl ){
+      if( pMem1->enc==pColl->enc ){
+        /* The strings are already in the correct encoding.  Call the
+        ** comparison function directly */
+        return pColl->xCmp(pColl->pUser,pMem1->n,pMem1->z,pMem2->n,pMem2->z);
+      }else{
+        u8 origEnc = pMem1->enc;
+        const void *v1, *v2;
+        int n1, n2;
+        /* Convert the strings into the encoding that the comparison
+        ** function expects */
+        v1 = sqlite3ValueText((sqlite3_value*)pMem1, pColl->enc);
+        n1 = v1==0 ? 0 : pMem1->n;
+        assert( n1==sqlite3ValueBytes((sqlite3_value*)pMem1, pColl->enc) );
+        v2 = sqlite3ValueText((sqlite3_value*)pMem2, pColl->enc);
+        n2 = v2==0 ? 0 : pMem2->n;
+        assert( n2==sqlite3ValueBytes((sqlite3_value*)pMem2, pColl->enc) );
+        /* Do the comparison */
+        rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);
+        /* Convert the strings back into the database encoding */
+        sqlite3ValueText((sqlite3_value*)pMem1, origEnc);
+        sqlite3ValueText((sqlite3_value*)pMem2, origEnc);
+        return rc;
+      }
+    }
+    /* If a NULL pointer was passed as the collate function, fall through
+    ** to the blob case and use memcmp().  */
+  }
+ 
+  /* Both values must be blobs.  Compare using memcmp().  */
+  rc = memcmp(pMem1->z, pMem2->z, (pMem1->n>pMem2->n)?pMem2->n:pMem1->n);
+  if( rc==0 ){
+    rc = pMem1->n - pMem2->n;
+  }
+  return rc;
+}
+
+/*
+** Move data out of a btree key or data field and into a Mem structure.
+** The data or key is taken from the entry that pCur is currently pointing
+** to.  offset and amt determine what portion of the data or key to retrieve.
+** key is true to get the key or false to get data.  The result is written
+** into the pMem element.
+**
+** The pMem structure is assumed to be uninitialized.  Any prior content
+** is overwritten without being freed.
+**
+** If this routine fails for any reason (malloc returns NULL or unable
+** to read from the disk) then the pMem is left in an inconsistent state.
+*/
+int sqlite3VdbeMemFromBtree(
+  BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
+  int offset,       /* Offset from the start of data to return bytes from. */
+  int amt,          /* Number of bytes to return. */
+  int key,          /* If true, retrieve from the btree key, not data. */
+  Mem *pMem         /* OUT: Return data in this Mem structure. */
+){
+  char *zData;       /* Data from the btree layer */
+  int available = 0; /* Number of bytes available on the local btree page */
+  sqlite3 *db;       /* Database connection */
+  int rc = SQLITE_OK;
+
+  db = sqlite3BtreeCursorDb(pCur);
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( key ){
+    zData = (char *)sqlite3BtreeKeyFetch(pCur, &available);
+  }else{
+    zData = (char *)sqlite3BtreeDataFetch(pCur, &available);
+  }
+  assert( zData!=0 );
+
+  if( offset+amt<=available && ((pMem->flags&MEM_Dyn)==0 || pMem->xDel) ){
+    sqlite3VdbeMemRelease(pMem);
+    pMem->z = &zData[offset];
+    pMem->flags = MEM_Blob|MEM_Ephem;
+  }else if( SQLITE_OK==(rc = sqlite3VdbeMemGrow(pMem, amt+2, 0)) ){
+    pMem->flags = MEM_Blob|MEM_Dyn|MEM_Term;
+    pMem->enc = 0;
+    pMem->type = SQLITE_BLOB;
+    if( key ){
+      rc = sqlite3BtreeKey(pCur, offset, amt, pMem->z);
+    }else{
+      rc = sqlite3BtreeData(pCur, offset, amt, pMem->z);
+    }
+    pMem->z[amt] = 0;
+    pMem->z[amt+1] = 0;
+    if( rc!=SQLITE_OK ){
+      sqlite3VdbeMemRelease(pMem);
+    }
+  }
+  pMem->n = amt;
+
+  return rc;
+}
+
+#if 0
+/*
+** Perform various checks on the memory cell pMem. An assert() will
+** fail if pMem is internally inconsistent.
+*/
+void sqlite3VdbeMemSanity(Mem *pMem){
+  int flags = pMem->flags;
+  assert( flags!=0 );  /* Must define some type */
+  if( flags & (MEM_Str|MEM_Blob) ){
+    int x = flags & (MEM_Static|MEM_Dyn|MEM_Ephem|MEM_Short);
+    assert( x!=0 );            /* Strings must define a string subtype */
+    assert( (x & (x-1))==0 );  /* Only one string subtype can be defined */
+    assert( pMem->z!=0 );      /* Strings must have a value */
+    /* Mem.z points to Mem.zShort iff the subtype is MEM_Short */
+    assert( (x & MEM_Short)==0 || pMem->z==pMem->zShort );
+    assert( (x & MEM_Short)!=0 || pMem->z!=pMem->zShort );
+    /* No destructor unless there is MEM_Dyn */
+    assert( pMem->xDel==0 || (pMem->flags & MEM_Dyn)!=0 );
+
+    if( (flags & MEM_Str) ){
+      assert( pMem->enc==SQLITE_UTF8 || 
+              pMem->enc==SQLITE_UTF16BE ||
+              pMem->enc==SQLITE_UTF16LE 
+      );
+      /* If the string is UTF-8 encoded and nul terminated, then pMem->n
+      ** must be the length of the string.  (Later:)  If the database file
+      ** has been corrupted, '\000' characters might have been inserted
+      ** into the middle of the string.  In that case, the strlen() might
+      ** be less.
+      */
+      if( pMem->enc==SQLITE_UTF8 && (flags & MEM_Term) ){ 
+        assert( strlen(pMem->z)<=pMem->n );
+        assert( pMem->z[pMem->n]==0 );
+      }
+    }
+  }else{
+    /* Cannot define a string subtype for non-string objects */
+    assert( (pMem->flags & (MEM_Static|MEM_Dyn|MEM_Ephem|MEM_Short))==0 );
+    assert( pMem->xDel==0 );
+  }
+  /* MEM_Null excludes all other types */
+  assert( (pMem->flags&(MEM_Str|MEM_Int|MEM_Real|MEM_Blob))==0
+          || (pMem->flags&MEM_Null)==0 );
+  /* If the MEM is both real and integer, the values are equal */
+  assert( (pMem->flags & (MEM_Int|MEM_Real))!=(MEM_Int|MEM_Real) 
+          || pMem->r==pMem->u.i );
+}
+#endif
+
+/* This function is only available internally, it is not part of the
+** external API. It works in a similar way to sqlite3_value_text(),
+** except the data returned is in the encoding specified by the second
+** parameter, which must be one of SQLITE_UTF16BE, SQLITE_UTF16LE or
+** SQLITE_UTF8.
+**
+** (2006-02-16:)  The enc value can be or-ed with SQLITE_UTF16_ALIGNED.
+** If that is the case, then the result must be aligned on an even byte
+** boundary.
+*/
+const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){
+  if( !pVal ) return 0;
+
+  assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
+  assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
+
+  if( pVal->flags&MEM_Null ){
+    return 0;
+  }
+  assert( (MEM_Blob>>3) == MEM_Str );
+  pVal->flags |= (pVal->flags & MEM_Blob)>>3;
+  expandBlob(pVal);
+  if( pVal->flags&MEM_Str ){
+    sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED);
+    if( (enc & SQLITE_UTF16_ALIGNED)!=0 && 1==(1&SQLITE_PTR_TO_INT(pVal->z)) ){
+      assert( (pVal->flags & (MEM_Ephem|MEM_Static))!=0 );
+      if( sqlite3VdbeMemMakeWriteable(pVal)!=SQLITE_OK ){
+        return 0;
+      }
+    }
+    sqlite3VdbeMemNulTerminate(pVal);
+  }else{
+    assert( (pVal->flags&MEM_Blob)==0 );
+    sqlite3VdbeMemStringify(pVal, enc);
+    assert( 0==(1&(int)pVal->z) );
+  }
+  assert(pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) || pVal->db==0
+              || pVal->db->mallocFailed );
+  if( pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) ){
+    return pVal->z;
+  }else{
+    return 0;
+  }
+}
+
+/*
+** Create a new sqlite3_value object.
+*/
+sqlite3_value *sqlite3ValueNew(sqlite3 *db){
+  Mem *p = sqlite3DbMallocZero(db, sizeof(*p));
+  if( p ){
+    p->flags = MEM_Null;
+    p->type = SQLITE_NULL;
+    p->db = db;
+  }
+  return p;
+}
+
+/*
+** Create a new sqlite3_value object, containing the value of pExpr.
+**
+** This only works for very simple expressions that consist of one constant
+** token (i.e. "5", "5.1", "'a string'"). If the expression can
+** be converted directly into a value, then the value is allocated and
+** a pointer written to *ppVal. The caller is responsible for deallocating
+** the value by passing it to sqlite3ValueFree() later on. If the expression
+** cannot be converted to a value, then *ppVal is set to NULL.
+*/
+int sqlite3ValueFromExpr(
+  sqlite3 *db,              /* The database connection */
+  Expr *pExpr,              /* The expression to evaluate */
+  u8 enc,                   /* Encoding to use */
+  u8 affinity,              /* Affinity to use */
+  sqlite3_value **ppVal     /* Write the new value here */
+){
+  int op;
+  char *zVal = 0;
+  sqlite3_value *pVal = 0;
+
+  if( !pExpr ){
+    *ppVal = 0;
+    return SQLITE_OK;
+  }
+  op = pExpr->op;
+
+  if( op==TK_STRING || op==TK_FLOAT || op==TK_INTEGER ){
+    zVal = sqlite3DbStrNDup(db, (char*)pExpr->token.z, pExpr->token.n);
+    pVal = sqlite3ValueNew(db);
+    if( !zVal || !pVal ) goto no_mem;
+    sqlite3Dequote(zVal);
+    sqlite3ValueSetStr(pVal, -1, zVal, SQLITE_UTF8, SQLITE_DYNAMIC);
+    if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_NONE ){
+      sqlite3ValueApplyAffinity(pVal, SQLITE_AFF_NUMERIC, enc);
+    }else{
+      sqlite3ValueApplyAffinity(pVal, affinity, enc);
+    }
+  }else if( op==TK_UMINUS ) {
+    if( SQLITE_OK==sqlite3ValueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal) ){
+      pVal->u.i = -1 * pVal->u.i;
+      pVal->r = -1.0 * pVal->r;
+    }
+  }
+#ifndef SQLITE_OMIT_BLOB_LITERAL
+  else if( op==TK_BLOB ){
+    int nVal;
+    assert( pExpr->token.n>=3 );
+    assert( pExpr->token.z[0]=='x' || pExpr->token.z[0]=='X' );
+    assert( pExpr->token.z[1]=='\'' );
+    assert( pExpr->token.z[pExpr->token.n-1]=='\'' );
+    pVal = sqlite3ValueNew(db);
+    nVal = pExpr->token.n - 3;
+    zVal = (char*)pExpr->token.z + 2;
+    sqlite3VdbeMemSetStr(pVal, sqlite3HexToBlob(db, zVal, nVal), nVal/2,
+                         0, SQLITE_DYNAMIC);
+  }
+#endif
+
+  *ppVal = pVal;
+  return SQLITE_OK;
+
+no_mem:
+  db->mallocFailed = 1;
+  sqlite3DbFree(db, zVal);
+  sqlite3ValueFree(pVal);
+  *ppVal = 0;
+  return SQLITE_NOMEM;
+}
+
+/*
+** Change the string value of an sqlite3_value object
+*/
+void sqlite3ValueSetStr(
+  sqlite3_value *v,     /* Value to be set */
+  int n,                /* Length of string z */
+  const void *z,        /* Text of the new string */
+  u8 enc,               /* Encoding to use */
+  void (*xDel)(void*)   /* Destructor for the string */
+){
+  if( v ) sqlite3VdbeMemSetStr((Mem *)v, z, n, enc, xDel);
+}
+
+/*
+** Free an sqlite3_value object
+*/
+void sqlite3ValueFree(sqlite3_value *v){
+  if( !v ) return;
+  sqlite3VdbeMemRelease((Mem *)v);
+  sqlite3DbFree(((Mem*)v)->db, v);
+}
+
+/*
+** Return the number of bytes in the sqlite3_value object assuming
+** that it uses the encoding "enc"
+*/
+int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){
+  Mem *p = (Mem*)pVal;
+  if( (p->flags & MEM_Blob)!=0 || sqlite3ValueText(pVal, enc) ){
+    if( p->flags & MEM_Zero ){
+      return p->n+p->u.i;
+    }else{
+      return p->n;
+    }
+  }
+  return 0;
+}
diff --git a/third_party/sqlite/src/vtab.c b/third_party/sqlite/src/vtab.c
new file mode 100755
index 0000000..bd18c479
--- /dev/null
+++ b/third_party/sqlite/src/vtab.c
@@ -0,0 +1,838 @@
+/*
+** 2006 June 10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code used to help implement virtual tables.
+**
+** $Id: vtab.c,v 1.74 2008/08/02 03:50:39 drh Exp $
+*/
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+#include "sqliteInt.h"
+
+static int createModule(
+  sqlite3 *db,                    /* Database in which module is registered */
+  const char *zName,              /* Name assigned to this module */
+  const sqlite3_module *pModule,  /* The definition of the module */
+  void *pAux,                     /* Context pointer for xCreate/xConnect */
+  void (*xDestroy)(void *)        /* Module destructor function */
+) {
+  int rc, nName;
+  Module *pMod;
+
+  sqlite3_mutex_enter(db->mutex);
+  nName = strlen(zName);
+  pMod = (Module *)sqlite3DbMallocRaw(db, sizeof(Module) + nName + 1);
+  if( pMod ){
+    Module *pDel;
+    char *zCopy = (char *)(&pMod[1]);
+    memcpy(zCopy, zName, nName+1);
+    pMod->zName = zCopy;
+    pMod->pModule = pModule;
+    pMod->pAux = pAux;
+    pMod->xDestroy = xDestroy;
+    pDel = (Module *)sqlite3HashInsert(&db->aModule, zCopy, nName, (void*)pMod);
+    if( pDel && pDel->xDestroy ){
+      pDel->xDestroy(pDel->pAux);
+    }
+    sqlite3DbFree(db, pDel);
+    if( pDel==pMod ){
+      db->mallocFailed = 1;
+    }
+    sqlite3ResetInternalSchema(db, 0);
+  }
+  rc = sqlite3ApiExit(db, SQLITE_OK);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+
+/*
+** External API function used to create a new virtual-table module.
+*/
+int sqlite3_create_module(
+  sqlite3 *db,                    /* Database in which module is registered */
+  const char *zName,              /* Name assigned to this module */
+  const sqlite3_module *pModule,  /* The definition of the module */
+  void *pAux                      /* Context pointer for xCreate/xConnect */
+){
+  return createModule(db, zName, pModule, pAux, 0);
+}
+
+/*
+** External API function used to create a new virtual-table module.
+*/
+int sqlite3_create_module_v2(
+  sqlite3 *db,                    /* Database in which module is registered */
+  const char *zName,              /* Name assigned to this module */
+  const sqlite3_module *pModule,  /* The definition of the module */
+  void *pAux,                     /* Context pointer for xCreate/xConnect */
+  void (*xDestroy)(void *)        /* Module destructor function */
+){
+  return createModule(db, zName, pModule, pAux, xDestroy);
+}
+
+/*
+** Lock the virtual table so that it cannot be disconnected.
+** Locks nest.  Every lock should have a corresponding unlock.
+** If an unlock is omitted, resources leaks will occur.  
+**
+** If a disconnect is attempted while a virtual table is locked,
+** the disconnect is deferred until all locks have been removed.
+*/
+void sqlite3VtabLock(sqlite3_vtab *pVtab){
+  pVtab->nRef++;
+}
+
+/*
+** Unlock a virtual table.  When the last lock is removed,
+** disconnect the virtual table.
+*/
+void sqlite3VtabUnlock(sqlite3 *db, sqlite3_vtab *pVtab){
+  pVtab->nRef--;
+  assert(db);
+  assert( sqlite3SafetyCheckOk(db) );
+  if( pVtab->nRef==0 ){
+    if( db->magic==SQLITE_MAGIC_BUSY ){
+      (void)sqlite3SafetyOff(db);
+      pVtab->pModule->xDisconnect(pVtab);
+      (void)sqlite3SafetyOn(db);
+    } else {
+      pVtab->pModule->xDisconnect(pVtab);
+    }
+  }
+}
+
+/*
+** Clear any and all virtual-table information from the Table record.
+** This routine is called, for example, just before deleting the Table
+** record.
+*/
+void sqlite3VtabClear(Table *p){
+  sqlite3_vtab *pVtab = p->pVtab;
+  sqlite3 *db = p->db;
+  if( pVtab ){
+    assert( p->pMod && p->pMod->pModule );
+    sqlite3VtabUnlock(db, pVtab);
+    p->pVtab = 0;
+  }
+  if( p->azModuleArg ){
+    int i;
+    for(i=0; i<p->nModuleArg; i++){
+      sqlite3DbFree(db, p->azModuleArg[i]);
+    }
+    sqlite3DbFree(db, p->azModuleArg);
+  }
+}
+
+/*
+** Add a new module argument to pTable->azModuleArg[].
+** The string is not copied - the pointer is stored.  The
+** string will be freed automatically when the table is
+** deleted.
+*/
+static void addModuleArgument(sqlite3 *db, Table *pTable, char *zArg){
+  int i = pTable->nModuleArg++;
+  int nBytes = sizeof(char *)*(1+pTable->nModuleArg);
+  char **azModuleArg;
+  azModuleArg = sqlite3DbRealloc(db, pTable->azModuleArg, nBytes);
+  if( azModuleArg==0 ){
+    int j;
+    for(j=0; j<i; j++){
+      sqlite3DbFree(db, pTable->azModuleArg[j]);
+    }
+    sqlite3DbFree(db, zArg);
+    sqlite3DbFree(db, pTable->azModuleArg);
+    pTable->nModuleArg = 0;
+  }else{
+    azModuleArg[i] = zArg;
+    azModuleArg[i+1] = 0;
+  }
+  pTable->azModuleArg = azModuleArg;
+}
+
+/*
+** The parser calls this routine when it first sees a CREATE VIRTUAL TABLE
+** statement.  The module name has been parsed, but the optional list
+** of parameters that follow the module name are still pending.
+*/
+void sqlite3VtabBeginParse(
+  Parse *pParse,        /* Parsing context */
+  Token *pName1,        /* Name of new table, or database name */
+  Token *pName2,        /* Name of new table or NULL */
+  Token *pModuleName    /* Name of the module for the virtual table */
+){
+  int iDb;              /* The database the table is being created in */
+  Table *pTable;        /* The new virtual table */
+  sqlite3 *db;          /* Database connection */
+
+  if( pParse->db->flags & SQLITE_SharedCache ){
+    sqlite3ErrorMsg(pParse, "Cannot use virtual tables in shared-cache mode");
+    return;
+  }
+
+  sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, 0);
+  pTable = pParse->pNewTable;
+  if( pTable==0 || pParse->nErr ) return;
+  assert( 0==pTable->pIndex );
+
+  db = pParse->db;
+  iDb = sqlite3SchemaToIndex(db, pTable->pSchema);
+  assert( iDb>=0 );
+
+  pTable->isVirtual = 1;
+  pTable->nModuleArg = 0;
+  addModuleArgument(db, pTable, sqlite3NameFromToken(db, pModuleName));
+  addModuleArgument(db, pTable, sqlite3DbStrDup(db, db->aDb[iDb].zName));
+  addModuleArgument(db, pTable, sqlite3DbStrDup(db, pTable->zName));
+  pParse->sNameToken.n = pModuleName->z + pModuleName->n - pName1->z;
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  /* Creating a virtual table invokes the authorization callback twice.
+  ** The first invocation, to obtain permission to INSERT a row into the
+  ** sqlite_master table, has already been made by sqlite3StartTable().
+  ** The second call, to obtain permission to create the table, is made now.
+  */
+  if( pTable->azModuleArg ){
+    sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName, 
+            pTable->azModuleArg[0], pParse->db->aDb[iDb].zName);
+  }
+#endif
+}
+
+/*
+** This routine takes the module argument that has been accumulating
+** in pParse->zArg[] and appends it to the list of arguments on the
+** virtual table currently under construction in pParse->pTable.
+*/
+static void addArgumentToVtab(Parse *pParse){
+  if( pParse->sArg.z && pParse->pNewTable ){
+    const char *z = (const char*)pParse->sArg.z;
+    int n = pParse->sArg.n;
+    sqlite3 *db = pParse->db;
+    addModuleArgument(db, pParse->pNewTable, sqlite3DbStrNDup(db, z, n));
+  }
+}
+
+/*
+** The parser calls this routine after the CREATE VIRTUAL TABLE statement
+** has been completely parsed.
+*/
+void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
+  Table *pTab;        /* The table being constructed */
+  sqlite3 *db;        /* The database connection */
+  char *zModule;      /* The module name of the table: USING modulename */
+  Module *pMod = 0;
+
+  addArgumentToVtab(pParse);
+  pParse->sArg.z = 0;
+
+  /* Lookup the module name. */
+  pTab = pParse->pNewTable;
+  if( pTab==0 ) return;
+  db = pParse->db;
+  if( pTab->nModuleArg<1 ) return;
+  zModule = pTab->azModuleArg[0];
+  pMod = (Module *)sqlite3HashFind(&db->aModule, zModule, strlen(zModule));
+  pTab->pMod = pMod;
+  
+  /* If the CREATE VIRTUAL TABLE statement is being entered for the
+  ** first time (in other words if the virtual table is actually being
+  ** created now instead of just being read out of sqlite_master) then
+  ** do additional initialization work and store the statement text
+  ** in the sqlite_master table.
+  */
+  if( !db->init.busy ){
+    char *zStmt;
+    char *zWhere;
+    int iDb;
+    Vdbe *v;
+
+    /* Compute the complete text of the CREATE VIRTUAL TABLE statement */
+    if( pEnd ){
+      pParse->sNameToken.n = pEnd->z - pParse->sNameToken.z + pEnd->n;
+    }
+    zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken);
+
+    /* A slot for the record has already been allocated in the 
+    ** SQLITE_MASTER table.  We just need to update that slot with all
+    ** the information we've collected.  
+    **
+    ** The VM register number pParse->regRowid holds the rowid of an
+    ** entry in the sqlite_master table tht was created for this vtab
+    ** by sqlite3StartTable().
+    */
+    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+    sqlite3NestedParse(pParse,
+      "UPDATE %Q.%s "
+         "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
+       "WHERE rowid=#%d",
+      db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
+      pTab->zName,
+      pTab->zName,
+      zStmt,
+      pParse->regRowid
+    );
+    sqlite3DbFree(db, zStmt);
+    v = sqlite3GetVdbe(pParse);
+    sqlite3ChangeCookie(pParse, iDb);
+
+    sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
+    zWhere = sqlite3MPrintf(db, "name='%q'", pTab->zName);
+    sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 1, 0, zWhere, P4_DYNAMIC);
+    sqlite3VdbeAddOp4(v, OP_VCreate, iDb, 0, 0, 
+                         pTab->zName, strlen(pTab->zName) + 1);
+  }
+
+  /* If we are rereading the sqlite_master table create the in-memory
+  ** record of the table. If the module has already been registered,
+  ** also call the xConnect method here.
+  */
+  else {
+    Table *pOld;
+    Schema *pSchema = pTab->pSchema;
+    const char *zName = pTab->zName;
+    int nName = strlen(zName) + 1;
+    pOld = sqlite3HashInsert(&pSchema->tblHash, zName, nName, pTab);
+    if( pOld ){
+      db->mallocFailed = 1;
+      assert( pTab==pOld );  /* Malloc must have failed inside HashInsert() */
+      return;
+    }
+    pSchema->db = pParse->db;
+    pParse->pNewTable = 0;
+  }
+}
+
+/*
+** The parser calls this routine when it sees the first token
+** of an argument to the module name in a CREATE VIRTUAL TABLE statement.
+*/
+void sqlite3VtabArgInit(Parse *pParse){
+  addArgumentToVtab(pParse);
+  pParse->sArg.z = 0;
+  pParse->sArg.n = 0;
+}
+
+/*
+** The parser calls this routine for each token after the first token
+** in an argument to the module name in a CREATE VIRTUAL TABLE statement.
+*/
+void sqlite3VtabArgExtend(Parse *pParse, Token *p){
+  Token *pArg = &pParse->sArg;
+  if( pArg->z==0 ){
+    pArg->z = p->z;
+    pArg->n = p->n;
+  }else{
+    assert(pArg->z < p->z);
+    pArg->n = (p->z + p->n - pArg->z);
+  }
+}
+
+/*
+** Invoke a virtual table constructor (either xCreate or xConnect). The
+** pointer to the function to invoke is passed as the fourth parameter
+** to this procedure.
+*/
+static int vtabCallConstructor(
+  sqlite3 *db, 
+  Table *pTab,
+  Module *pMod,
+  int (*xConstruct)(sqlite3*,void*,int,const char*const*,sqlite3_vtab**,char**),
+  char **pzErr
+){
+  int rc;
+  int rc2;
+  sqlite3_vtab *pVtab = 0;
+  const char *const*azArg = (const char *const*)pTab->azModuleArg;
+  int nArg = pTab->nModuleArg;
+  char *zErr = 0;
+  char *zModuleName = sqlite3MPrintf(db, "%s", pTab->zName);
+
+  if( !zModuleName ){
+    return SQLITE_NOMEM;
+  }
+
+  assert( !db->pVTab );
+  assert( xConstruct );
+
+  db->pVTab = pTab;
+  rc = sqlite3SafetyOff(db);
+  assert( rc==SQLITE_OK );
+  rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVtab, &zErr);
+  rc2 = sqlite3SafetyOn(db);
+  if( rc==SQLITE_OK && pVtab ){
+    pVtab->pModule = pMod->pModule;
+    pVtab->nRef = 1;
+    pTab->pVtab = pVtab;
+  }
+
+  if( SQLITE_OK!=rc ){
+    if( zErr==0 ){
+      *pzErr = sqlite3MPrintf(db, "vtable constructor failed: %s", zModuleName);
+    }else {
+      *pzErr = sqlite3MPrintf(db, "%s", zErr);
+      sqlite3DbFree(db, zErr);
+    }
+  }else if( db->pVTab ){
+    const char *zFormat = "vtable constructor did not declare schema: %s";
+    *pzErr = sqlite3MPrintf(db, zFormat, pTab->zName);
+    rc = SQLITE_ERROR;
+  } 
+  if( rc==SQLITE_OK ){
+    rc = rc2;
+  }
+  db->pVTab = 0;
+  sqlite3DbFree(db, zModuleName);
+
+  /* If everything went according to plan, loop through the columns
+  ** of the table to see if any of them contain the token "hidden".
+  ** If so, set the Column.isHidden flag and remove the token from
+  ** the type string.
+  */
+  if( rc==SQLITE_OK ){
+    int iCol;
+    for(iCol=0; iCol<pTab->nCol; iCol++){
+      char *zType = pTab->aCol[iCol].zType;
+      int nType;
+      int i = 0;
+      if( !zType ) continue;
+      nType = strlen(zType);
+      if( sqlite3StrNICmp("hidden", zType, 6) || (zType[6] && zType[6]!=' ') ){
+        for(i=0; i<nType; i++){
+          if( (0==sqlite3StrNICmp(" hidden", &zType[i], 7))
+           && (zType[i+7]=='\0' || zType[i+7]==' ')
+          ){
+            i++;
+            break;
+          }
+        }
+      }
+      if( i<nType ){
+        int j;
+        int nDel = 6 + (zType[i+6] ? 1 : 0);
+        for(j=i; (j+nDel)<=nType; j++){
+          zType[j] = zType[j+nDel];
+        }
+        if( zType[i]=='\0' && i>0 ){
+          assert(zType[i-1]==' ');
+          zType[i-1] = '\0';
+        }
+        pTab->aCol[iCol].isHidden = 1;
+      }
+    }
+  }
+  return rc;
+}
+
+/*
+** This function is invoked by the parser to call the xConnect() method
+** of the virtual table pTab. If an error occurs, an error code is returned 
+** and an error left in pParse.
+**
+** This call is a no-op if table pTab is not a virtual table.
+*/
+int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){
+  Module *pMod;
+  int rc = SQLITE_OK;
+
+  if( !pTab || !pTab->isVirtual || pTab->pVtab ){
+    return SQLITE_OK;
+  }
+
+  pMod = pTab->pMod;
+  if( !pMod ){
+    const char *zModule = pTab->azModuleArg[0];
+    sqlite3ErrorMsg(pParse, "no such module: %s", zModule);
+    rc = SQLITE_ERROR;
+  } else {
+    char *zErr = 0;
+    sqlite3 *db = pParse->db;
+    rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xConnect, &zErr);
+    if( rc!=SQLITE_OK ){
+      sqlite3ErrorMsg(pParse, "%s", zErr);
+    }
+    sqlite3DbFree(db, zErr);
+  }
+
+  return rc;
+}
+
+/*
+** Add the virtual table pVtab to the array sqlite3.aVTrans[].
+*/
+static int addToVTrans(sqlite3 *db, sqlite3_vtab *pVtab){
+  const int ARRAY_INCR = 5;
+
+  /* Grow the sqlite3.aVTrans array if required */
+  if( (db->nVTrans%ARRAY_INCR)==0 ){
+    sqlite3_vtab **aVTrans;
+    int nBytes = sizeof(sqlite3_vtab *) * (db->nVTrans + ARRAY_INCR);
+    aVTrans = sqlite3DbRealloc(db, (void *)db->aVTrans, nBytes);
+    if( !aVTrans ){
+      return SQLITE_NOMEM;
+    }
+    memset(&aVTrans[db->nVTrans], 0, sizeof(sqlite3_vtab *)*ARRAY_INCR);
+    db->aVTrans = aVTrans;
+  }
+
+  /* Add pVtab to the end of sqlite3.aVTrans */
+  db->aVTrans[db->nVTrans++] = pVtab;
+  sqlite3VtabLock(pVtab);
+  return SQLITE_OK;
+}
+
+/*
+** This function is invoked by the vdbe to call the xCreate method
+** of the virtual table named zTab in database iDb. 
+**
+** If an error occurs, *pzErr is set to point an an English language
+** description of the error and an SQLITE_XXX error code is returned.
+** In this case the caller must call sqlite3DbFree(db, ) on *pzErr.
+*/
+int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){
+  int rc = SQLITE_OK;
+  Table *pTab;
+  Module *pMod;
+  const char *zModule;
+
+  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
+  assert(pTab && pTab->isVirtual && !pTab->pVtab);
+  pMod = pTab->pMod;
+  zModule = pTab->azModuleArg[0];
+
+  /* If the module has been registered and includes a Create method, 
+  ** invoke it now. If the module has not been registered, return an 
+  ** error. Otherwise, do nothing.
+  */
+  if( !pMod ){
+    *pzErr = sqlite3MPrintf(db, "no such module: %s", zModule);
+    rc = SQLITE_ERROR;
+  }else{
+    rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xCreate, pzErr);
+  }
+
+  if( rc==SQLITE_OK && pTab->pVtab ){
+      rc = addToVTrans(db, pTab->pVtab);
+  }
+
+  return rc;
+}
+
+/*
+** This function is used to set the schema of a virtual table.  It is only
+** valid to call this function from within the xCreate() or xConnect() of a
+** virtual table module.
+*/
+int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
+  Parse sParse;
+
+  int rc = SQLITE_OK;
+  Table *pTab;
+  char *zErr = 0;
+
+  sqlite3_mutex_enter(db->mutex);
+  pTab = db->pVTab;
+  if( !pTab ){
+    sqlite3Error(db, SQLITE_MISUSE, 0);
+    sqlite3_mutex_leave(db->mutex);
+    return SQLITE_MISUSE;
+  }
+  assert(pTab->isVirtual && pTab->nCol==0 && pTab->aCol==0);
+
+  memset(&sParse, 0, sizeof(Parse));
+  sParse.declareVtab = 1;
+  sParse.db = db;
+
+  if( 
+      SQLITE_OK == sqlite3RunParser(&sParse, zCreateTable, &zErr) && 
+      sParse.pNewTable && 
+      !sParse.pNewTable->pSelect && 
+      !sParse.pNewTable->isVirtual 
+  ){
+    pTab->aCol = sParse.pNewTable->aCol;
+    pTab->nCol = sParse.pNewTable->nCol;
+    sParse.pNewTable->nCol = 0;
+    sParse.pNewTable->aCol = 0;
+    db->pVTab = 0;
+  } else {
+    sqlite3Error(db, SQLITE_ERROR, zErr);
+    sqlite3DbFree(db, zErr);
+    rc = SQLITE_ERROR;
+  }
+  sParse.declareVtab = 0;
+
+  sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe);
+  sqlite3DeleteTable(sParse.pNewTable);
+  sParse.pNewTable = 0;
+
+  assert( (rc&0xff)==rc );
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** This function is invoked by the vdbe to call the xDestroy method
+** of the virtual table named zTab in database iDb. This occurs
+** when a DROP TABLE is mentioned.
+**
+** This call is a no-op if zTab is not a virtual table.
+*/
+int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab)
+{
+  int rc = SQLITE_OK;
+  Table *pTab;
+
+  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
+  assert(pTab);
+  if( pTab->pVtab ){
+    int (*xDestroy)(sqlite3_vtab *pVTab) = pTab->pMod->pModule->xDestroy;
+    rc = sqlite3SafetyOff(db);
+    assert( rc==SQLITE_OK );
+    if( xDestroy ){
+      rc = xDestroy(pTab->pVtab);
+    }
+    (void)sqlite3SafetyOn(db);
+    if( rc==SQLITE_OK ){
+      int i;
+      for(i=0; i<db->nVTrans; i++){
+        if( db->aVTrans[i]==pTab->pVtab ){
+          db->aVTrans[i] = db->aVTrans[--db->nVTrans];
+          break;
+        }
+      }
+      pTab->pVtab = 0;
+    }
+  }
+
+  return rc;
+}
+
+/*
+** This function invokes either the xRollback or xCommit method
+** of each of the virtual tables in the sqlite3.aVTrans array. The method
+** called is identified by the second argument, "offset", which is
+** the offset of the method to call in the sqlite3_module structure.
+**
+** The array is cleared after invoking the callbacks. 
+*/
+static void callFinaliser(sqlite3 *db, int offset){
+  int i;
+  if( db->aVTrans ){
+    for(i=0; i<db->nVTrans && db->aVTrans[i]; i++){
+      sqlite3_vtab *pVtab = db->aVTrans[i];
+      int (*x)(sqlite3_vtab *);
+      x = *(int (**)(sqlite3_vtab *))((char *)pVtab->pModule + offset);
+      if( x ) x(pVtab);
+      sqlite3VtabUnlock(db, pVtab);
+    }
+    sqlite3DbFree(db, db->aVTrans);
+    db->nVTrans = 0;
+    db->aVTrans = 0;
+  }
+}
+
+/*
+** Invoke the xSync method of all virtual tables in the sqlite3.aVTrans
+** array. Return the error code for the first error that occurs, or
+** SQLITE_OK if all xSync operations are successful.
+**
+** Set *pzErrmsg to point to a buffer that should be released using 
+** sqlite3DbFree() containing an error message, if one is available.
+*/
+int sqlite3VtabSync(sqlite3 *db, char **pzErrmsg){
+  int i;
+  int rc = SQLITE_OK;
+  int rcsafety;
+  sqlite3_vtab **aVTrans = db->aVTrans;
+
+  rc = sqlite3SafetyOff(db);
+  db->aVTrans = 0;
+  for(i=0; rc==SQLITE_OK && i<db->nVTrans && aVTrans[i]; i++){
+    sqlite3_vtab *pVtab = aVTrans[i];
+    int (*x)(sqlite3_vtab *);
+    x = pVtab->pModule->xSync;
+    if( x ){
+      rc = x(pVtab);
+      sqlite3DbFree(db, *pzErrmsg);
+      *pzErrmsg = pVtab->zErrMsg;
+      pVtab->zErrMsg = 0;
+    }
+  }
+  db->aVTrans = aVTrans;
+  rcsafety = sqlite3SafetyOn(db);
+
+  if( rc==SQLITE_OK ){
+    rc = rcsafety;
+  }
+  return rc;
+}
+
+/*
+** Invoke the xRollback method of all virtual tables in the 
+** sqlite3.aVTrans array. Then clear the array itself.
+*/
+int sqlite3VtabRollback(sqlite3 *db){
+  callFinaliser(db, offsetof(sqlite3_module,xRollback));
+  return SQLITE_OK;
+}
+
+/*
+** Invoke the xCommit method of all virtual tables in the 
+** sqlite3.aVTrans array. Then clear the array itself.
+*/
+int sqlite3VtabCommit(sqlite3 *db){
+  callFinaliser(db, offsetof(sqlite3_module,xCommit));
+  return SQLITE_OK;
+}
+
+/*
+** If the virtual table pVtab supports the transaction interface
+** (xBegin/xRollback/xCommit and optionally xSync) and a transaction is
+** not currently open, invoke the xBegin method now.
+**
+** If the xBegin call is successful, place the sqlite3_vtab pointer
+** in the sqlite3.aVTrans array.
+*/
+int sqlite3VtabBegin(sqlite3 *db, sqlite3_vtab *pVtab){
+  int rc = SQLITE_OK;
+  const sqlite3_module *pModule;
+
+  /* Special case: If db->aVTrans is NULL and db->nVTrans is greater
+  ** than zero, then this function is being called from within a
+  ** virtual module xSync() callback. It is illegal to write to 
+  ** virtual module tables in this case, so return SQLITE_LOCKED.
+  */
+  if( 0==db->aVTrans && db->nVTrans>0 ){
+    return SQLITE_LOCKED;
+  }
+  if( !pVtab ){
+    return SQLITE_OK;
+  } 
+  pModule = pVtab->pModule;
+
+  if( pModule->xBegin ){
+    int i;
+
+
+    /* If pVtab is already in the aVTrans array, return early */
+    for(i=0; (i<db->nVTrans) && 0!=db->aVTrans[i]; i++){
+      if( db->aVTrans[i]==pVtab ){
+        return SQLITE_OK;
+      }
+    }
+
+    /* Invoke the xBegin method */
+    rc = pModule->xBegin(pVtab);
+    if( rc==SQLITE_OK ){
+      rc = addToVTrans(db, pVtab);
+    }
+  }
+  return rc;
+}
+
+/*
+** The first parameter (pDef) is a function implementation.  The
+** second parameter (pExpr) is the first argument to this function.
+** If pExpr is a column in a virtual table, then let the virtual
+** table implementation have an opportunity to overload the function.
+**
+** This routine is used to allow virtual table implementations to
+** overload MATCH, LIKE, GLOB, and REGEXP operators.
+**
+** Return either the pDef argument (indicating no change) or a 
+** new FuncDef structure that is marked as ephemeral using the
+** SQLITE_FUNC_EPHEM flag.
+*/
+FuncDef *sqlite3VtabOverloadFunction(
+  sqlite3 *db,    /* Database connection for reporting malloc problems */
+  FuncDef *pDef,  /* Function to possibly overload */
+  int nArg,       /* Number of arguments to the function */
+  Expr *pExpr     /* First argument to the function */
+){
+  Table *pTab;
+  sqlite3_vtab *pVtab;
+  sqlite3_module *pMod;
+  void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
+  void *pArg;
+  FuncDef *pNew;
+  int rc = 0;
+  char *zLowerName;
+  unsigned char *z;
+
+
+  /* Check to see the left operand is a column in a virtual table */
+  if( pExpr==0 ) return pDef;
+  if( pExpr->op!=TK_COLUMN ) return pDef;
+  pTab = pExpr->pTab;
+  if( pTab==0 ) return pDef;
+  if( !pTab->isVirtual ) return pDef;
+  pVtab = pTab->pVtab;
+  assert( pVtab!=0 );
+  assert( pVtab->pModule!=0 );
+  pMod = (sqlite3_module *)pVtab->pModule;
+  if( pMod->xFindFunction==0 ) return pDef;
+ 
+  /* Call the xFindFunction method on the virtual table implementation
+  ** to see if the implementation wants to overload this function 
+  */
+  zLowerName = sqlite3DbStrDup(db, pDef->zName);
+  if( zLowerName ){
+    for(z=(unsigned char*)zLowerName; *z; z++){
+      *z = sqlite3UpperToLower[*z];
+    }
+    rc = pMod->xFindFunction(pVtab, nArg, zLowerName, &xFunc, &pArg);
+    sqlite3DbFree(db, zLowerName);
+    if( pVtab->zErrMsg ){
+      sqlite3Error(db, rc, "%s", pVtab->zErrMsg);
+      sqlite3DbFree(db, pVtab->zErrMsg);
+      pVtab->zErrMsg = 0;
+    }
+  }
+  if( rc==0 ){
+    return pDef;
+  }
+
+  /* Create a new ephemeral function definition for the overloaded
+  ** function */
+  pNew = sqlite3DbMallocZero(db, sizeof(*pNew) + strlen(pDef->zName) );
+  if( pNew==0 ){
+    return pDef;
+  }
+  *pNew = *pDef;
+  memcpy(pNew->zName, pDef->zName, strlen(pDef->zName)+1);
+  pNew->xFunc = xFunc;
+  pNew->pUserData = pArg;
+  pNew->flags |= SQLITE_FUNC_EPHEM;
+  return pNew;
+}
+
+/*
+** Make sure virtual table pTab is contained in the pParse->apVirtualLock[]
+** array so that an OP_VBegin will get generated for it.  Add pTab to the
+** array if it is missing.  If pTab is already in the array, this routine
+** is a no-op.
+*/
+void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){
+  int i, n;
+  assert( IsVirtual(pTab) );
+  for(i=0; i<pParse->nVtabLock; i++){
+    if( pTab==pParse->apVtabLock[i] ) return;
+  }
+  n = (pParse->nVtabLock+1)*sizeof(pParse->apVtabLock[0]);
+  pParse->apVtabLock = sqlite3_realloc(pParse->apVtabLock, n);
+  if( pParse->apVtabLock ){
+    pParse->apVtabLock[pParse->nVtabLock++] = pTab;
+  }else{
+    pParse->db->mallocFailed = 1;
+  }
+}
+
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
diff --git a/third_party/sqlite/src/where.c b/third_party/sqlite/src/where.c
new file mode 100755
index 0000000..9c70c31
--- /dev/null
+++ b/third_party/sqlite/src/where.c
@@ -0,0 +1,2895 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This module contains C code that generates VDBE code used to process
+** the WHERE clause of SQL statements.  This module is responsible for
+** generating the code that loops through a table looking for applicable
+** rows.  Indices are selected and used to speed the search when doing
+** so is applicable.  Because this module is responsible for selecting
+** indices, you might also think of this module as the "query optimizer".
+**
+** $Id: where.c,v 1.319 2008/08/01 17:37:41 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+
+/*
+** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
+*/
+#define BMS  (sizeof(Bitmask)*8)
+
+/*
+** Trace output macros
+*/
+#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
+int sqlite3WhereTrace = 0;
+#endif
+#if 0
+# define WHERETRACE(X)  if(sqlite3WhereTrace) sqlite3DebugPrintf X
+#else
+# define WHERETRACE(X)
+#endif
+
+/* Forward reference
+*/
+typedef struct WhereClause WhereClause;
+typedef struct ExprMaskSet ExprMaskSet;
+
+/*
+** The query generator uses an array of instances of this structure to
+** help it analyze the subexpressions of the WHERE clause.  Each WHERE
+** clause subexpression is separated from the others by an AND operator.
+**
+** All WhereTerms are collected into a single WhereClause structure.  
+** The following identity holds:
+**
+**        WhereTerm.pWC->a[WhereTerm.idx] == WhereTerm
+**
+** When a term is of the form:
+**
+**              X <op> <expr>
+**
+** where X is a column name and <op> is one of certain operators,
+** then WhereTerm.leftCursor and WhereTerm.leftColumn record the
+** cursor number and column number for X.  WhereTerm.operator records
+** the <op> using a bitmask encoding defined by WO_xxx below.  The
+** use of a bitmask encoding for the operator allows us to search
+** quickly for terms that match any of several different operators.
+**
+** prereqRight and prereqAll record sets of cursor numbers,
+** but they do so indirectly.  A single ExprMaskSet structure translates
+** cursor number into bits and the translated bit is stored in the prereq
+** fields.  The translation is used in order to maximize the number of
+** bits that will fit in a Bitmask.  The VDBE cursor numbers might be
+** spread out over the non-negative integers.  For example, the cursor
+** numbers might be 3, 8, 9, 10, 20, 23, 41, and 45.  The ExprMaskSet
+** translates these sparse cursor numbers into consecutive integers
+** beginning with 0 in order to make the best possible use of the available
+** bits in the Bitmask.  So, in the example above, the cursor numbers
+** would be mapped into integers 0 through 7.
+*/
+typedef struct WhereTerm WhereTerm;
+struct WhereTerm {
+  Expr *pExpr;            /* Pointer to the subexpression */
+  i16 iParent;            /* Disable pWC->a[iParent] when this term disabled */
+  i16 leftCursor;         /* Cursor number of X in "X <op> <expr>" */
+  i16 leftColumn;         /* Column number of X in "X <op> <expr>" */
+  u16 eOperator;          /* A WO_xx value describing <op> */
+  u8 flags;               /* Bit flags.  See below */
+  u8 nChild;              /* Number of children that must disable us */
+  WhereClause *pWC;       /* The clause this term is part of */
+  Bitmask prereqRight;    /* Bitmask of tables used by pRight */
+  Bitmask prereqAll;      /* Bitmask of tables referenced by p */
+};
+
+/*
+** Allowed values of WhereTerm.flags
+*/
+#define TERM_DYNAMIC    0x01   /* Need to call sqlite3ExprDelete(db, pExpr) */
+#define TERM_VIRTUAL    0x02   /* Added by the optimizer.  Do not code */
+#define TERM_CODED      0x04   /* This term is already coded */
+#define TERM_COPIED     0x08   /* Has a child */
+#define TERM_OR_OK      0x10   /* Used during OR-clause processing */
+
+/*
+** An instance of the following structure holds all information about a
+** WHERE clause.  Mostly this is a container for one or more WhereTerms.
+*/
+struct WhereClause {
+  Parse *pParse;           /* The parser context */
+  ExprMaskSet *pMaskSet;   /* Mapping of table indices to bitmasks */
+  int nTerm;               /* Number of terms */
+  int nSlot;               /* Number of entries in a[] */
+  WhereTerm *a;            /* Each a[] describes a term of the WHERE cluase */
+  WhereTerm aStatic[10];   /* Initial static space for a[] */
+};
+
+/*
+** An instance of the following structure keeps track of a mapping
+** between VDBE cursor numbers and bits of the bitmasks in WhereTerm.
+**
+** The VDBE cursor numbers are small integers contained in 
+** SrcList_item.iCursor and Expr.iTable fields.  For any given WHERE 
+** clause, the cursor numbers might not begin with 0 and they might
+** contain gaps in the numbering sequence.  But we want to make maximum
+** use of the bits in our bitmasks.  This structure provides a mapping
+** from the sparse cursor numbers into consecutive integers beginning
+** with 0.
+**
+** If ExprMaskSet.ix[A]==B it means that The A-th bit of a Bitmask
+** corresponds VDBE cursor number B.  The A-th bit of a bitmask is 1<<A.
+**
+** For example, if the WHERE clause expression used these VDBE
+** cursors:  4, 5, 8, 29, 57, 73.  Then the  ExprMaskSet structure
+** would map those cursor numbers into bits 0 through 5.
+**
+** Note that the mapping is not necessarily ordered.  In the example
+** above, the mapping might go like this:  4->3, 5->1, 8->2, 29->0,
+** 57->5, 73->4.  Or one of 719 other combinations might be used. It
+** does not really matter.  What is important is that sparse cursor
+** numbers all get mapped into bit numbers that begin with 0 and contain
+** no gaps.
+*/
+struct ExprMaskSet {
+  int n;                        /* Number of assigned cursor values */
+  int ix[sizeof(Bitmask)*8];    /* Cursor assigned to each bit */
+};
+
+
+/*
+** Bitmasks for the operators that indices are able to exploit.  An
+** OR-ed combination of these values can be used when searching for
+** terms in the where clause.
+*/
+#define WO_IN     1
+#define WO_EQ     2
+#define WO_LT     (WO_EQ<<(TK_LT-TK_EQ))
+#define WO_LE     (WO_EQ<<(TK_LE-TK_EQ))
+#define WO_GT     (WO_EQ<<(TK_GT-TK_EQ))
+#define WO_GE     (WO_EQ<<(TK_GE-TK_EQ))
+#define WO_MATCH  64
+#define WO_ISNULL 128
+
+/*
+** Value for flags returned by bestIndex().  
+**
+** The least significant byte is reserved as a mask for WO_ values above.
+** The WhereLevel.flags field is usually set to WO_IN|WO_EQ|WO_ISNULL.
+** But if the table is the right table of a left join, WhereLevel.flags
+** is set to WO_IN|WO_EQ.  The WhereLevel.flags field can then be used as
+** the "op" parameter to findTerm when we are resolving equality constraints.
+** ISNULL constraints will then not be used on the right table of a left
+** join.  Tickets #2177 and #2189.
+*/
+#define WHERE_ROWID_EQ     0x000100   /* rowid=EXPR or rowid IN (...) */
+#define WHERE_ROWID_RANGE  0x000200   /* rowid<EXPR and/or rowid>EXPR */
+#define WHERE_COLUMN_EQ    0x001000   /* x=EXPR or x IN (...) */
+#define WHERE_COLUMN_RANGE 0x002000   /* x<EXPR and/or x>EXPR */
+#define WHERE_COLUMN_IN    0x004000   /* x IN (...) */
+#define WHERE_TOP_LIMIT    0x010000   /* x<EXPR or x<=EXPR constraint */
+#define WHERE_BTM_LIMIT    0x020000   /* x>EXPR or x>=EXPR constraint */
+#define WHERE_IDX_ONLY     0x080000   /* Use index only - omit table */
+#define WHERE_ORDERBY      0x100000   /* Output will appear in correct order */
+#define WHERE_REVERSE      0x200000   /* Scan in reverse order */
+#define WHERE_UNIQUE       0x400000   /* Selects no more than one row */
+#define WHERE_VIRTUALTABLE 0x800000   /* Use virtual-table processing */
+
+/*
+** Initialize a preallocated WhereClause structure.
+*/
+static void whereClauseInit(
+  WhereClause *pWC,        /* The WhereClause to be initialized */
+  Parse *pParse,           /* The parsing context */
+  ExprMaskSet *pMaskSet    /* Mapping from table indices to bitmasks */
+){
+  pWC->pParse = pParse;
+  pWC->pMaskSet = pMaskSet;
+  pWC->nTerm = 0;
+  pWC->nSlot = ArraySize(pWC->aStatic);
+  pWC->a = pWC->aStatic;
+}
+
+/*
+** Deallocate a WhereClause structure.  The WhereClause structure
+** itself is not freed.  This routine is the inverse of whereClauseInit().
+*/
+static void whereClauseClear(WhereClause *pWC){
+  int i;
+  WhereTerm *a;
+  sqlite3 *db = pWC->pParse->db;
+  for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){
+    if( a->flags & TERM_DYNAMIC ){
+      sqlite3ExprDelete(db, a->pExpr);
+    }
+  }
+  if( pWC->a!=pWC->aStatic ){
+    sqlite3DbFree(db, pWC->a);
+  }
+}
+
+/*
+** Add a new entries to the WhereClause structure.  Increase the allocated
+** space as necessary.
+**
+** If the flags argument includes TERM_DYNAMIC, then responsibility
+** for freeing the expression p is assumed by the WhereClause object.
+**
+** WARNING:  This routine might reallocate the space used to store
+** WhereTerms.  All pointers to WhereTerms should be invalidated after
+** calling this routine.  Such pointers may be reinitialized by referencing
+** the pWC->a[] array.
+*/
+static int whereClauseInsert(WhereClause *pWC, Expr *p, int flags){
+  WhereTerm *pTerm;
+  int idx;
+  if( pWC->nTerm>=pWC->nSlot ){
+    WhereTerm *pOld = pWC->a;
+    sqlite3 *db = pWC->pParse->db;
+    pWC->a = sqlite3DbMallocRaw(db, sizeof(pWC->a[0])*pWC->nSlot*2 );
+    if( pWC->a==0 ){
+      if( flags & TERM_DYNAMIC ){
+        sqlite3ExprDelete(db, p);
+      }
+      pWC->a = pOld;
+      return 0;
+    }
+    memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm);
+    if( pOld!=pWC->aStatic ){
+      sqlite3DbFree(db, pOld);
+    }
+    pWC->nSlot *= 2;
+  }
+  pTerm = &pWC->a[idx = pWC->nTerm];
+  pWC->nTerm++;
+  pTerm->pExpr = p;
+  pTerm->flags = flags;
+  pTerm->pWC = pWC;
+  pTerm->iParent = -1;
+  return idx;
+}
+
+/*
+** This routine identifies subexpressions in the WHERE clause where
+** each subexpression is separated by the AND operator or some other
+** operator specified in the op parameter.  The WhereClause structure
+** is filled with pointers to subexpressions.  For example:
+**
+**    WHERE  a=='hello' AND coalesce(b,11)<10 AND (c+12!=d OR c==22)
+**           \________/     \_______________/     \________________/
+**            slot[0]            slot[1]               slot[2]
+**
+** The original WHERE clause in pExpr is unaltered.  All this routine
+** does is make slot[] entries point to substructure within pExpr.
+**
+** In the previous sentence and in the diagram, "slot[]" refers to
+** the WhereClause.a[] array.  This array grows as needed to contain
+** all terms of the WHERE clause.
+*/
+static void whereSplit(WhereClause *pWC, Expr *pExpr, int op){
+  if( pExpr==0 ) return;
+  if( pExpr->op!=op ){
+    whereClauseInsert(pWC, pExpr, 0);
+  }else{
+    whereSplit(pWC, pExpr->pLeft, op);
+    whereSplit(pWC, pExpr->pRight, op);
+  }
+}
+
+/*
+** Initialize an expression mask set
+*/
+#define initMaskSet(P)  memset(P, 0, sizeof(*P))
+
+/*
+** Return the bitmask for the given cursor number.  Return 0 if
+** iCursor is not in the set.
+*/
+static Bitmask getMask(ExprMaskSet *pMaskSet, int iCursor){
+  int i;
+  for(i=0; i<pMaskSet->n; i++){
+    if( pMaskSet->ix[i]==iCursor ){
+      return ((Bitmask)1)<<i;
+    }
+  }
+  return 0;
+}
+
+/*
+** Create a new mask for cursor iCursor.
+**
+** There is one cursor per table in the FROM clause.  The number of
+** tables in the FROM clause is limited by a test early in the
+** sqlite3WhereBegin() routine.  So we know that the pMaskSet->ix[]
+** array will never overflow.
+*/
+static void createMask(ExprMaskSet *pMaskSet, int iCursor){
+  assert( pMaskSet->n < ArraySize(pMaskSet->ix) );
+  pMaskSet->ix[pMaskSet->n++] = iCursor;
+}
+
+/*
+** This routine walks (recursively) an expression tree and generates
+** a bitmask indicating which tables are used in that expression
+** tree.
+**
+** In order for this routine to work, the calling function must have
+** previously invoked sqlite3ExprResolveNames() on the expression.  See
+** the header comment on that routine for additional information.
+** The sqlite3ExprResolveNames() routines looks for column names and
+** sets their opcodes to TK_COLUMN and their Expr.iTable fields to
+** the VDBE cursor number of the table.  This routine just has to
+** translate the cursor numbers into bitmask values and OR all
+** the bitmasks together.
+*/
+static Bitmask exprListTableUsage(ExprMaskSet*, ExprList*);
+static Bitmask exprSelectTableUsage(ExprMaskSet*, Select*);
+static Bitmask exprTableUsage(ExprMaskSet *pMaskSet, Expr *p){
+  Bitmask mask = 0;
+  if( p==0 ) return 0;
+  if( p->op==TK_COLUMN ){
+    mask = getMask(pMaskSet, p->iTable);
+    return mask;
+  }
+  mask = exprTableUsage(pMaskSet, p->pRight);
+  mask |= exprTableUsage(pMaskSet, p->pLeft);
+  mask |= exprListTableUsage(pMaskSet, p->pList);
+  mask |= exprSelectTableUsage(pMaskSet, p->pSelect);
+  return mask;
+}
+static Bitmask exprListTableUsage(ExprMaskSet *pMaskSet, ExprList *pList){
+  int i;
+  Bitmask mask = 0;
+  if( pList ){
+    for(i=0; i<pList->nExpr; i++){
+      mask |= exprTableUsage(pMaskSet, pList->a[i].pExpr);
+    }
+  }
+  return mask;
+}
+static Bitmask exprSelectTableUsage(ExprMaskSet *pMaskSet, Select *pS){
+  Bitmask mask = 0;
+  while( pS ){
+    mask |= exprListTableUsage(pMaskSet, pS->pEList);
+    mask |= exprListTableUsage(pMaskSet, pS->pGroupBy);
+    mask |= exprListTableUsage(pMaskSet, pS->pOrderBy);
+    mask |= exprTableUsage(pMaskSet, pS->pWhere);
+    mask |= exprTableUsage(pMaskSet, pS->pHaving);
+    pS = pS->pPrior;
+  }
+  return mask;
+}
+
+/*
+** Return TRUE if the given operator is one of the operators that is
+** allowed for an indexable WHERE clause term.  The allowed operators are
+** "=", "<", ">", "<=", ">=", and "IN".
+*/
+static int allowedOp(int op){
+  assert( TK_GT>TK_EQ && TK_GT<TK_GE );
+  assert( TK_LT>TK_EQ && TK_LT<TK_GE );
+  assert( TK_LE>TK_EQ && TK_LE<TK_GE );
+  assert( TK_GE==TK_EQ+4 );
+  return op==TK_IN || (op>=TK_EQ && op<=TK_GE) || op==TK_ISNULL;
+}
+
+/*
+** Swap two objects of type T.
+*/
+#define SWAP(TYPE,A,B) {TYPE t=A; A=B; B=t;}
+
+/*
+** Commute a comparison operator.  Expressions of the form "X op Y"
+** are converted into "Y op X".
+**
+** If a collation sequence is associated with either the left or right
+** side of the comparison, it remains associated with the same side after
+** the commutation. So "Y collate NOCASE op X" becomes 
+** "X collate NOCASE op Y". This is because any collation sequence on
+** the left hand side of a comparison overrides any collation sequence 
+** attached to the right. For the same reason the EP_ExpCollate flag
+** is not commuted.
+*/
+static void exprCommute(Expr *pExpr){
+  u16 expRight = (pExpr->pRight->flags & EP_ExpCollate);
+  u16 expLeft = (pExpr->pLeft->flags & EP_ExpCollate);
+  assert( allowedOp(pExpr->op) && pExpr->op!=TK_IN );
+  SWAP(CollSeq*,pExpr->pRight->pColl,pExpr->pLeft->pColl);
+  pExpr->pRight->flags = (pExpr->pRight->flags & ~EP_ExpCollate) | expLeft;
+  pExpr->pLeft->flags = (pExpr->pLeft->flags & ~EP_ExpCollate) | expRight;
+  SWAP(Expr*,pExpr->pRight,pExpr->pLeft);
+  if( pExpr->op>=TK_GT ){
+    assert( TK_LT==TK_GT+2 );
+    assert( TK_GE==TK_LE+2 );
+    assert( TK_GT>TK_EQ );
+    assert( TK_GT<TK_LE );
+    assert( pExpr->op>=TK_GT && pExpr->op<=TK_GE );
+    pExpr->op = ((pExpr->op-TK_GT)^2)+TK_GT;
+  }
+}
+
+/*
+** Translate from TK_xx operator to WO_xx bitmask.
+*/
+static int operatorMask(int op){
+  int c;
+  assert( allowedOp(op) );
+  if( op==TK_IN ){
+    c = WO_IN;
+  }else if( op==TK_ISNULL ){
+    c = WO_ISNULL;
+  }else{
+    c = WO_EQ<<(op-TK_EQ);
+  }
+  assert( op!=TK_ISNULL || c==WO_ISNULL );
+  assert( op!=TK_IN || c==WO_IN );
+  assert( op!=TK_EQ || c==WO_EQ );
+  assert( op!=TK_LT || c==WO_LT );
+  assert( op!=TK_LE || c==WO_LE );
+  assert( op!=TK_GT || c==WO_GT );
+  assert( op!=TK_GE || c==WO_GE );
+  return c;
+}
+
+/*
+** Search for a term in the WHERE clause that is of the form "X <op> <expr>"
+** where X is a reference to the iColumn of table iCur and <op> is one of
+** the WO_xx operator codes specified by the op parameter.
+** Return a pointer to the term.  Return 0 if not found.
+*/
+static WhereTerm *findTerm(
+  WhereClause *pWC,     /* The WHERE clause to be searched */
+  int iCur,             /* Cursor number of LHS */
+  int iColumn,          /* Column number of LHS */
+  Bitmask notReady,     /* RHS must not overlap with this mask */
+  u16 op,               /* Mask of WO_xx values describing operator */
+  Index *pIdx           /* Must be compatible with this index, if not NULL */
+){
+  WhereTerm *pTerm;
+  int k;
+  assert( iCur>=0 );
+  for(pTerm=pWC->a, k=pWC->nTerm; k; k--, pTerm++){
+    if( pTerm->leftCursor==iCur
+       && (pTerm->prereqRight & notReady)==0
+       && pTerm->leftColumn==iColumn
+       && (pTerm->eOperator & op)!=0
+    ){
+      if( pIdx && pTerm->eOperator!=WO_ISNULL ){
+        Expr *pX = pTerm->pExpr;
+        CollSeq *pColl;
+        char idxaff;
+        int j;
+        Parse *pParse = pWC->pParse;
+
+        idxaff = pIdx->pTable->aCol[iColumn].affinity;
+        if( !sqlite3IndexAffinityOk(pX, idxaff) ) continue;
+
+        /* Figure out the collation sequence required from an index for
+        ** it to be useful for optimising expression pX. Store this
+        ** value in variable pColl.
+        */
+        assert(pX->pLeft);
+        pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
+        if( !pColl ){
+          pColl = pParse->db->pDfltColl;
+        }
+
+        for(j=0; pIdx->aiColumn[j]!=iColumn; j++){
+          if( NEVER(j>=pIdx->nColumn) ) return 0;
+        }
+        if( sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ) continue;
+      }
+      return pTerm;
+    }
+  }
+  return 0;
+}
+
+/* Forward reference */
+static void exprAnalyze(SrcList*, WhereClause*, int);
+
+/*
+** Call exprAnalyze on all terms in a WHERE clause.  
+**
+**
+*/
+static void exprAnalyzeAll(
+  SrcList *pTabList,       /* the FROM clause */
+  WhereClause *pWC         /* the WHERE clause to be analyzed */
+){
+  int i;
+  for(i=pWC->nTerm-1; i>=0; i--){
+    exprAnalyze(pTabList, pWC, i);
+  }
+}
+
+#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
+/*
+** Check to see if the given expression is a LIKE or GLOB operator that
+** can be optimized using inequality constraints.  Return TRUE if it is
+** so and false if not.
+**
+** In order for the operator to be optimizible, the RHS must be a string
+** literal that does not begin with a wildcard.  
+*/
+static int isLikeOrGlob(
+  sqlite3 *db,      /* The database */
+  Expr *pExpr,      /* Test this expression */
+  int *pnPattern,   /* Number of non-wildcard prefix characters */
+  int *pisComplete, /* True if the only wildcard is % in the last character */
+  int *pnoCase      /* True if uppercase is equivalent to lowercase */
+){
+  const char *z;
+  Expr *pRight, *pLeft;
+  ExprList *pList;
+  int c, cnt;
+  char wc[3];
+  CollSeq *pColl;
+
+  if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, wc) ){
+    return 0;
+  }
+#ifdef SQLITE_EBCDIC
+  if( *pnoCase ) return 0;
+#endif
+  pList = pExpr->pList;
+  pRight = pList->a[0].pExpr;
+  if( pRight->op!=TK_STRING
+   && (pRight->op!=TK_REGISTER || pRight->iColumn!=TK_STRING) ){
+    return 0;
+  }
+  pLeft = pList->a[1].pExpr;
+  if( pLeft->op!=TK_COLUMN ){
+    return 0;
+  }
+  pColl = pLeft->pColl;
+  assert( pColl!=0 || pLeft->iColumn==-1 );
+  if( pColl==0 ){
+    /* No collation is defined for the ROWID.  Use the default. */
+    pColl = db->pDfltColl;
+  }
+  if( (pColl->type!=SQLITE_COLL_BINARY || *pnoCase) &&
+      (pColl->type!=SQLITE_COLL_NOCASE || !*pnoCase) ){
+    return 0;
+  }
+  sqlite3DequoteExpr(db, pRight);
+  z = (char *)pRight->token.z;
+  cnt = 0;
+  if( z ){
+    while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){ cnt++; }
+  }
+  if( cnt==0 || 255==(u8)z[cnt] ){
+    return 0;
+  }
+  *pisComplete = z[cnt]==wc[0] && z[cnt+1]==0;
+  *pnPattern = cnt;
+  return 1;
+}
+#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
+
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Check to see if the given expression is of the form
+**
+**         column MATCH expr
+**
+** If it is then return TRUE.  If not, return FALSE.
+*/
+static int isMatchOfColumn(
+  Expr *pExpr      /* Test this expression */
+){
+  ExprList *pList;
+
+  if( pExpr->op!=TK_FUNCTION ){
+    return 0;
+  }
+  if( pExpr->token.n!=5 ||
+       sqlite3StrNICmp((const char*)pExpr->token.z,"match",5)!=0 ){
+    return 0;
+  }
+  pList = pExpr->pList;
+  if( pList->nExpr!=2 ){
+    return 0;
+  }
+  if( pList->a[1].pExpr->op != TK_COLUMN ){
+    return 0;
+  }
+  return 1;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** If the pBase expression originated in the ON or USING clause of
+** a join, then transfer the appropriate markings over to derived.
+*/
+static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
+  pDerived->flags |= pBase->flags & EP_FromJoin;
+  pDerived->iRightJoinTable = pBase->iRightJoinTable;
+}
+
+#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
+/*
+** Return TRUE if the given term of an OR clause can be converted
+** into an IN clause.  The iCursor and iColumn define the left-hand
+** side of the IN clause.
+**
+** The context is that we have multiple OR-connected equality terms
+** like this:
+**
+**           a=<expr1> OR  a=<expr2> OR b=<expr3>  OR ...
+**
+** The pOrTerm input to this routine corresponds to a single term of
+** this OR clause.  In order for the term to be a candidate for
+** conversion to an IN operator, the following must be true:
+**
+**     *  The left-hand side of the term must be the column which
+**        is identified by iCursor and iColumn.
+**
+**     *  If the right-hand side is also a column, then the affinities
+**        of both right and left sides must be such that no type
+**        conversions are required on the right.  (Ticket #2249)
+**
+** If both of these conditions are true, then return true.  Otherwise
+** return false.
+*/
+static int orTermIsOptCandidate(WhereTerm *pOrTerm, int iCursor, int iColumn){
+  int affLeft, affRight;
+  assert( pOrTerm->eOperator==WO_EQ );
+  if( pOrTerm->leftCursor!=iCursor ){
+    return 0;
+  }
+  if( pOrTerm->leftColumn!=iColumn ){
+    return 0;
+  }
+  affRight = sqlite3ExprAffinity(pOrTerm->pExpr->pRight);
+  if( affRight==0 ){
+    return 1;
+  }
+  affLeft = sqlite3ExprAffinity(pOrTerm->pExpr->pLeft);
+  if( affRight!=affLeft ){
+    return 0;
+  }
+  return 1;
+}
+
+/*
+** Return true if the given term of an OR clause can be ignored during
+** a check to make sure all OR terms are candidates for optimization.
+** In other words, return true if a call to the orTermIsOptCandidate()
+** above returned false but it is not necessary to disqualify the
+** optimization.
+**
+** Suppose the original OR phrase was this:
+**
+**           a=4  OR  a=11  OR  a=b
+**
+** During analysis, the third term gets flipped around and duplicate
+** so that we are left with this:
+**
+**           a=4  OR  a=11  OR  a=b  OR  b=a
+**
+** Since the last two terms are duplicates, only one of them
+** has to qualify in order for the whole phrase to qualify.  When
+** this routine is called, we know that pOrTerm did not qualify.
+** This routine merely checks to see if pOrTerm has a duplicate that
+** might qualify.  If there is a duplicate that has not yet been
+** disqualified, then return true.  If there are no duplicates, or
+** the duplicate has also been disqualified, return false.
+*/
+static int orTermHasOkDuplicate(WhereClause *pOr, WhereTerm *pOrTerm){
+  if( pOrTerm->flags & TERM_COPIED ){
+    /* This is the original term.  The duplicate is to the left had
+    ** has not yet been analyzed and thus has not yet been disqualified. */
+    return 1;
+  }
+  if( (pOrTerm->flags & TERM_VIRTUAL)!=0
+     && (pOr->a[pOrTerm->iParent].flags & TERM_OR_OK)!=0 ){
+    /* This is a duplicate term.  The original qualified so this one
+    ** does not have to. */
+    return 1;
+  }
+  /* This is either a singleton term or else it is a duplicate for
+  ** which the original did not qualify.  Either way we are done for. */
+  return 0;
+}
+#endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */
+
+/*
+** The input to this routine is an WhereTerm structure with only the
+** "pExpr" field filled in.  The job of this routine is to analyze the
+** subexpression and populate all the other fields of the WhereTerm
+** structure.
+**
+** If the expression is of the form "<expr> <op> X" it gets commuted
+** to the standard form of "X <op> <expr>".  If the expression is of
+** the form "X <op> Y" where both X and Y are columns, then the original
+** expression is unchanged and a new virtual expression of the form
+** "Y <op> X" is added to the WHERE clause and analyzed separately.
+*/
+static void exprAnalyze(
+  SrcList *pSrc,            /* the FROM clause */
+  WhereClause *pWC,         /* the WHERE clause */
+  int idxTerm               /* Index of the term to be analyzed */
+){
+  WhereTerm *pTerm;
+  ExprMaskSet *pMaskSet;
+  Expr *pExpr;
+  Bitmask prereqLeft;
+  Bitmask prereqAll;
+  Bitmask extraRight = 0;
+  int nPattern;
+  int isComplete;
+  int noCase;
+  int op;
+  Parse *pParse = pWC->pParse;
+  sqlite3 *db = pParse->db;
+
+  if( db->mallocFailed ){
+    return;
+  }
+  pTerm = &pWC->a[idxTerm];
+  pMaskSet = pWC->pMaskSet;
+  pExpr = pTerm->pExpr;
+  prereqLeft = exprTableUsage(pMaskSet, pExpr->pLeft);
+  op = pExpr->op;
+  if( op==TK_IN ){
+    assert( pExpr->pRight==0 );
+    pTerm->prereqRight = exprListTableUsage(pMaskSet, pExpr->pList)
+                          | exprSelectTableUsage(pMaskSet, pExpr->pSelect);
+  }else if( op==TK_ISNULL ){
+    pTerm->prereqRight = 0;
+  }else{
+    pTerm->prereqRight = exprTableUsage(pMaskSet, pExpr->pRight);
+  }
+  prereqAll = exprTableUsage(pMaskSet, pExpr);
+  if( ExprHasProperty(pExpr, EP_FromJoin) ){
+    Bitmask x = getMask(pMaskSet, pExpr->iRightJoinTable);
+    prereqAll |= x;
+    extraRight = x-1;  /* ON clause terms may not be used with an index
+                       ** on left table of a LEFT JOIN.  Ticket #3015 */
+  }
+  pTerm->prereqAll = prereqAll;
+  pTerm->leftCursor = -1;
+  pTerm->iParent = -1;
+  pTerm->eOperator = 0;
+  if( allowedOp(op) && (pTerm->prereqRight & prereqLeft)==0 ){
+    Expr *pLeft = pExpr->pLeft;
+    Expr *pRight = pExpr->pRight;
+    if( pLeft->op==TK_COLUMN ){
+      pTerm->leftCursor = pLeft->iTable;
+      pTerm->leftColumn = pLeft->iColumn;
+      pTerm->eOperator = operatorMask(op);
+    }
+    if( pRight && pRight->op==TK_COLUMN ){
+      WhereTerm *pNew;
+      Expr *pDup;
+      if( pTerm->leftCursor>=0 ){
+        int idxNew;
+        pDup = sqlite3ExprDup(db, pExpr);
+        if( db->mallocFailed ){
+          sqlite3ExprDelete(db, pDup);
+          return;
+        }
+        idxNew = whereClauseInsert(pWC, pDup, TERM_VIRTUAL|TERM_DYNAMIC);
+        if( idxNew==0 ) return;
+        pNew = &pWC->a[idxNew];
+        pNew->iParent = idxTerm;
+        pTerm = &pWC->a[idxTerm];
+        pTerm->nChild = 1;
+        pTerm->flags |= TERM_COPIED;
+      }else{
+        pDup = pExpr;
+        pNew = pTerm;
+      }
+      exprCommute(pDup);
+      pLeft = pDup->pLeft;
+      pNew->leftCursor = pLeft->iTable;
+      pNew->leftColumn = pLeft->iColumn;
+      pNew->prereqRight = prereqLeft;
+      pNew->prereqAll = prereqAll;
+      pNew->eOperator = operatorMask(pDup->op);
+    }
+  }
+
+#ifndef SQLITE_OMIT_BETWEEN_OPTIMIZATION
+  /* If a term is the BETWEEN operator, create two new virtual terms
+  ** that define the range that the BETWEEN implements.
+  */
+  else if( pExpr->op==TK_BETWEEN ){
+    ExprList *pList = pExpr->pList;
+    int i;
+    static const u8 ops[] = {TK_GE, TK_LE};
+    assert( pList!=0 );
+    assert( pList->nExpr==2 );
+    for(i=0; i<2; i++){
+      Expr *pNewExpr;
+      int idxNew;
+      pNewExpr = sqlite3Expr(db, ops[i], sqlite3ExprDup(db, pExpr->pLeft),
+                             sqlite3ExprDup(db, pList->a[i].pExpr), 0);
+      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
+      exprAnalyze(pSrc, pWC, idxNew);
+      pTerm = &pWC->a[idxTerm];
+      pWC->a[idxNew].iParent = idxTerm;
+    }
+    pTerm->nChild = 2;
+  }
+#endif /* SQLITE_OMIT_BETWEEN_OPTIMIZATION */
+
+#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
+  /* Attempt to convert OR-connected terms into an IN operator so that
+  ** they can make use of indices.  Example:
+  **
+  **      x = expr1  OR  expr2 = x  OR  x = expr3
+  **
+  ** is converted into
+  **
+  **      x IN (expr1,expr2,expr3)
+  **
+  ** This optimization must be omitted if OMIT_SUBQUERY is defined because
+  ** the compiler for the the IN operator is part of sub-queries.
+  */
+  else if( pExpr->op==TK_OR ){
+    int ok;
+    int i, j;
+    int iColumn, iCursor;
+    WhereClause sOr;
+    WhereTerm *pOrTerm;
+
+    assert( (pTerm->flags & TERM_DYNAMIC)==0 );
+    whereClauseInit(&sOr, pWC->pParse, pMaskSet);
+    whereSplit(&sOr, pExpr, TK_OR);
+    exprAnalyzeAll(pSrc, &sOr);
+    assert( sOr.nTerm>=2 );
+    j = 0;
+    if( db->mallocFailed ) goto or_not_possible;
+    do{
+      assert( j<sOr.nTerm );
+      iColumn = sOr.a[j].leftColumn;
+      iCursor = sOr.a[j].leftCursor;
+      ok = iCursor>=0;
+      for(i=sOr.nTerm-1, pOrTerm=sOr.a; i>=0 && ok; i--, pOrTerm++){
+        if( pOrTerm->eOperator!=WO_EQ ){
+          goto or_not_possible;
+        }
+        if( orTermIsOptCandidate(pOrTerm, iCursor, iColumn) ){
+          pOrTerm->flags |= TERM_OR_OK;
+        }else if( orTermHasOkDuplicate(&sOr, pOrTerm) ){
+          pOrTerm->flags &= ~TERM_OR_OK;
+        }else{
+          ok = 0;
+        }
+      }
+    }while( !ok && (sOr.a[j++].flags & TERM_COPIED)!=0 && j<2 );
+    if( ok ){
+      ExprList *pList = 0;
+      Expr *pNew, *pDup;
+      Expr *pLeft = 0;
+      for(i=sOr.nTerm-1, pOrTerm=sOr.a; i>=0; i--, pOrTerm++){
+        if( (pOrTerm->flags & TERM_OR_OK)==0 ) continue;
+        pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight);
+        pList = sqlite3ExprListAppend(pWC->pParse, pList, pDup, 0);
+        pLeft = pOrTerm->pExpr->pLeft;
+      }
+      assert( pLeft!=0 );
+      pDup = sqlite3ExprDup(db, pLeft);
+      pNew = sqlite3Expr(db, TK_IN, pDup, 0, 0);
+      if( pNew ){
+        int idxNew;
+        transferJoinMarkings(pNew, pExpr);
+        pNew->pList = pList;
+        idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
+        exprAnalyze(pSrc, pWC, idxNew);
+        pTerm = &pWC->a[idxTerm];
+        pWC->a[idxNew].iParent = idxTerm;
+        pTerm->nChild = 1;
+      }else{
+        sqlite3ExprListDelete(db, pList);
+      }
+    }
+or_not_possible:
+    whereClauseClear(&sOr);
+  }
+#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
+
+#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
+  /* Add constraints to reduce the search space on a LIKE or GLOB
+  ** operator.
+  **
+  ** A like pattern of the form "x LIKE 'abc%'" is changed into constraints
+  **
+  **          x>='abc' AND x<'abd' AND x LIKE 'abc%'
+  **
+  ** The last character of the prefix "abc" is incremented to form the
+  ** termination condition "abd".
+  */
+  if( isLikeOrGlob(db, pExpr, &nPattern, &isComplete, &noCase) ){
+    Expr *pLeft, *pRight;
+    Expr *pStr1, *pStr2;
+    Expr *pNewExpr1, *pNewExpr2;
+    int idxNew1, idxNew2;
+
+    pLeft = pExpr->pList->a[1].pExpr;
+    pRight = pExpr->pList->a[0].pExpr;
+    pStr1 = sqlite3PExpr(pParse, TK_STRING, 0, 0, 0);
+    if( pStr1 ){
+      sqlite3TokenCopy(db, &pStr1->token, &pRight->token);
+      pStr1->token.n = nPattern;
+      pStr1->flags = EP_Dequoted;
+    }
+    pStr2 = sqlite3ExprDup(db, pStr1);
+    if( !db->mallocFailed ){
+      u8 c, *pC;
+      assert( pStr2->token.dyn );
+      pC = (u8*)&pStr2->token.z[nPattern-1];
+      c = *pC;
+      if( noCase ){
+        if( c=='@' ) isComplete = 0;
+        c = sqlite3UpperToLower[c];
+      }
+      *pC = c + 1;
+    }
+    pNewExpr1 = sqlite3PExpr(pParse, TK_GE, sqlite3ExprDup(db,pLeft), pStr1, 0);
+    idxNew1 = whereClauseInsert(pWC, pNewExpr1, TERM_VIRTUAL|TERM_DYNAMIC);
+    exprAnalyze(pSrc, pWC, idxNew1);
+    pNewExpr2 = sqlite3PExpr(pParse, TK_LT, sqlite3ExprDup(db,pLeft), pStr2, 0);
+    idxNew2 = whereClauseInsert(pWC, pNewExpr2, TERM_VIRTUAL|TERM_DYNAMIC);
+    exprAnalyze(pSrc, pWC, idxNew2);
+    pTerm = &pWC->a[idxTerm];
+    if( isComplete ){
+      pWC->a[idxNew1].iParent = idxTerm;
+      pWC->a[idxNew2].iParent = idxTerm;
+      pTerm->nChild = 2;
+    }
+  }
+#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  /* Add a WO_MATCH auxiliary term to the constraint set if the
+  ** current expression is of the form:  column MATCH expr.
+  ** This information is used by the xBestIndex methods of
+  ** virtual tables.  The native query optimizer does not attempt
+  ** to do anything with MATCH functions.
+  */
+  if( isMatchOfColumn(pExpr) ){
+    int idxNew;
+    Expr *pRight, *pLeft;
+    WhereTerm *pNewTerm;
+    Bitmask prereqColumn, prereqExpr;
+
+    pRight = pExpr->pList->a[0].pExpr;
+    pLeft = pExpr->pList->a[1].pExpr;
+    prereqExpr = exprTableUsage(pMaskSet, pRight);
+    prereqColumn = exprTableUsage(pMaskSet, pLeft);
+    if( (prereqExpr & prereqColumn)==0 ){
+      Expr *pNewExpr;
+      pNewExpr = sqlite3Expr(db, TK_MATCH, 0, sqlite3ExprDup(db, pRight), 0);
+      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
+      pNewTerm = &pWC->a[idxNew];
+      pNewTerm->prereqRight = prereqExpr;
+      pNewTerm->leftCursor = pLeft->iTable;
+      pNewTerm->leftColumn = pLeft->iColumn;
+      pNewTerm->eOperator = WO_MATCH;
+      pNewTerm->iParent = idxTerm;
+      pTerm = &pWC->a[idxTerm];
+      pTerm->nChild = 1;
+      pTerm->flags |= TERM_COPIED;
+      pNewTerm->prereqAll = pTerm->prereqAll;
+    }
+  }
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+  /* Prevent ON clause terms of a LEFT JOIN from being used to drive
+  ** an index for tables to the left of the join.
+  */
+  pTerm->prereqRight |= extraRight;
+}
+
+/*
+** Return TRUE if any of the expressions in pList->a[iFirst...] contain
+** a reference to any table other than the iBase table.
+*/
+static int referencesOtherTables(
+  ExprList *pList,          /* Search expressions in ths list */
+  ExprMaskSet *pMaskSet,    /* Mapping from tables to bitmaps */
+  int iFirst,               /* Be searching with the iFirst-th expression */
+  int iBase                 /* Ignore references to this table */
+){
+  Bitmask allowed = ~getMask(pMaskSet, iBase);
+  while( iFirst<pList->nExpr ){
+    if( (exprTableUsage(pMaskSet, pList->a[iFirst++].pExpr)&allowed)!=0 ){
+      return 1;
+    }
+  }
+  return 0;
+}
+
+
+/*
+** This routine decides if pIdx can be used to satisfy the ORDER BY
+** clause.  If it can, it returns 1.  If pIdx cannot satisfy the
+** ORDER BY clause, this routine returns 0.
+**
+** pOrderBy is an ORDER BY clause from a SELECT statement.  pTab is the
+** left-most table in the FROM clause of that same SELECT statement and
+** the table has a cursor number of "base".  pIdx is an index on pTab.
+**
+** nEqCol is the number of columns of pIdx that are used as equality
+** constraints.  Any of these columns may be missing from the ORDER BY
+** clause and the match can still be a success.
+**
+** All terms of the ORDER BY that match against the index must be either
+** ASC or DESC.  (Terms of the ORDER BY clause past the end of a UNIQUE
+** index do not need to satisfy this constraint.)  The *pbRev value is
+** set to 1 if the ORDER BY clause is all DESC and it is set to 0 if
+** the ORDER BY clause is all ASC.
+*/
+static int isSortingIndex(
+  Parse *pParse,          /* Parsing context */
+  ExprMaskSet *pMaskSet,  /* Mapping from table indices to bitmaps */
+  Index *pIdx,            /* The index we are testing */
+  int base,               /* Cursor number for the table to be sorted */
+  ExprList *pOrderBy,     /* The ORDER BY clause */
+  int nEqCol,             /* Number of index columns with == constraints */
+  int *pbRev              /* Set to 1 if ORDER BY is DESC */
+){
+  int i, j;                       /* Loop counters */
+  int sortOrder = 0;              /* XOR of index and ORDER BY sort direction */
+  int nTerm;                      /* Number of ORDER BY terms */
+  struct ExprList_item *pTerm;    /* A term of the ORDER BY clause */
+  sqlite3 *db = pParse->db;
+
+  assert( pOrderBy!=0 );
+  nTerm = pOrderBy->nExpr;
+  assert( nTerm>0 );
+
+  /* Match terms of the ORDER BY clause against columns of
+  ** the index.
+  **
+  ** Note that indices have pIdx->nColumn regular columns plus
+  ** one additional column containing the rowid.  The rowid column
+  ** of the index is also allowed to match against the ORDER BY
+  ** clause.
+  */
+  for(i=j=0, pTerm=pOrderBy->a; j<nTerm && i<=pIdx->nColumn; i++){
+    Expr *pExpr;       /* The expression of the ORDER BY pTerm */
+    CollSeq *pColl;    /* The collating sequence of pExpr */
+    int termSortOrder; /* Sort order for this term */
+    int iColumn;       /* The i-th column of the index.  -1 for rowid */
+    int iSortOrder;    /* 1 for DESC, 0 for ASC on the i-th index term */
+    const char *zColl; /* Name of the collating sequence for i-th index term */
+
+    pExpr = pTerm->pExpr;
+    if( pExpr->op!=TK_COLUMN || pExpr->iTable!=base ){
+      /* Can not use an index sort on anything that is not a column in the
+      ** left-most table of the FROM clause */
+      break;
+    }
+    pColl = sqlite3ExprCollSeq(pParse, pExpr);
+    if( !pColl ){
+      pColl = db->pDfltColl;
+    }
+    if( i<pIdx->nColumn ){
+      iColumn = pIdx->aiColumn[i];
+      if( iColumn==pIdx->pTable->iPKey ){
+        iColumn = -1;
+      }
+      iSortOrder = pIdx->aSortOrder[i];
+      zColl = pIdx->azColl[i];
+    }else{
+      iColumn = -1;
+      iSortOrder = 0;
+      zColl = pColl->zName;
+    }
+    if( pExpr->iColumn!=iColumn || sqlite3StrICmp(pColl->zName, zColl) ){
+      /* Term j of the ORDER BY clause does not match column i of the index */
+      if( i<nEqCol ){
+        /* If an index column that is constrained by == fails to match an
+        ** ORDER BY term, that is OK.  Just ignore that column of the index
+        */
+        continue;
+      }else if( i==pIdx->nColumn ){
+        /* Index column i is the rowid.  All other terms match. */
+        break;
+      }else{
+        /* If an index column fails to match and is not constrained by ==
+        ** then the index cannot satisfy the ORDER BY constraint.
+        */
+        return 0;
+      }
+    }
+    assert( pIdx->aSortOrder!=0 );
+    assert( pTerm->sortOrder==0 || pTerm->sortOrder==1 );
+    assert( iSortOrder==0 || iSortOrder==1 );
+    termSortOrder = iSortOrder ^ pTerm->sortOrder;
+    if( i>nEqCol ){
+      if( termSortOrder!=sortOrder ){
+        /* Indices can only be used if all ORDER BY terms past the
+        ** equality constraints are all either DESC or ASC. */
+        return 0;
+      }
+    }else{
+      sortOrder = termSortOrder;
+    }
+    j++;
+    pTerm++;
+    if( iColumn<0 && !referencesOtherTables(pOrderBy, pMaskSet, j, base) ){
+      /* If the indexed column is the primary key and everything matches
+      ** so far and none of the ORDER BY terms to the right reference other
+      ** tables in the join, then we are assured that the index can be used 
+      ** to sort because the primary key is unique and so none of the other
+      ** columns will make any difference
+      */
+      j = nTerm;
+    }
+  }
+
+  *pbRev = sortOrder!=0;
+  if( j>=nTerm ){
+    /* All terms of the ORDER BY clause are covered by this index so
+    ** this index can be used for sorting. */
+    return 1;
+  }
+  if( pIdx->onError!=OE_None && i==pIdx->nColumn
+      && !referencesOtherTables(pOrderBy, pMaskSet, j, base) ){
+    /* All terms of this index match some prefix of the ORDER BY clause
+    ** and the index is UNIQUE and no terms on the tail of the ORDER BY
+    ** clause reference other tables in a join.  If this is all true then
+    ** the order by clause is superfluous. */
+    return 1;
+  }
+  return 0;
+}
+
+/*
+** Check table to see if the ORDER BY clause in pOrderBy can be satisfied
+** by sorting in order of ROWID.  Return true if so and set *pbRev to be
+** true for reverse ROWID and false for forward ROWID order.
+*/
+static int sortableByRowid(
+  int base,               /* Cursor number for table to be sorted */
+  ExprList *pOrderBy,     /* The ORDER BY clause */
+  ExprMaskSet *pMaskSet,  /* Mapping from tables to bitmaps */
+  int *pbRev              /* Set to 1 if ORDER BY is DESC */
+){
+  Expr *p;
+
+  assert( pOrderBy!=0 );
+  assert( pOrderBy->nExpr>0 );
+  p = pOrderBy->a[0].pExpr;
+  if( p->op==TK_COLUMN && p->iTable==base && p->iColumn==-1
+    && !referencesOtherTables(pOrderBy, pMaskSet, 1, base) ){
+    *pbRev = pOrderBy->a[0].sortOrder;
+    return 1;
+  }
+  return 0;
+}
+
+/*
+** Prepare a crude estimate of the logarithm of the input value.
+** The results need not be exact.  This is only used for estimating
+** the total cost of performing operations with O(logN) or O(NlogN)
+** complexity.  Because N is just a guess, it is no great tragedy if
+** logN is a little off.
+*/
+static double estLog(double N){
+  double logN = 1;
+  double x = 10;
+  while( N>x ){
+    logN += 1;
+    x *= 10;
+  }
+  return logN;
+}
+
+/*
+** Two routines for printing the content of an sqlite3_index_info
+** structure.  Used for testing and debugging only.  If neither
+** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines
+** are no-ops.
+*/
+#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_DEBUG)
+static void TRACE_IDX_INPUTS(sqlite3_index_info *p){
+  int i;
+  if( !sqlite3WhereTrace ) return;
+  for(i=0; i<p->nConstraint; i++){
+    sqlite3DebugPrintf("  constraint[%d]: col=%d termid=%d op=%d usabled=%d\n",
+       i,
+       p->aConstraint[i].iColumn,
+       p->aConstraint[i].iTermOffset,
+       p->aConstraint[i].op,
+       p->aConstraint[i].usable);
+  }
+  for(i=0; i<p->nOrderBy; i++){
+    sqlite3DebugPrintf("  orderby[%d]: col=%d desc=%d\n",
+       i,
+       p->aOrderBy[i].iColumn,
+       p->aOrderBy[i].desc);
+  }
+}
+static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){
+  int i;
+  if( !sqlite3WhereTrace ) return;
+  for(i=0; i<p->nConstraint; i++){
+    sqlite3DebugPrintf("  usage[%d]: argvIdx=%d omit=%d\n",
+       i,
+       p->aConstraintUsage[i].argvIndex,
+       p->aConstraintUsage[i].omit);
+  }
+  sqlite3DebugPrintf("  idxNum=%d\n", p->idxNum);
+  sqlite3DebugPrintf("  idxStr=%s\n", p->idxStr);
+  sqlite3DebugPrintf("  orderByConsumed=%d\n", p->orderByConsumed);
+  sqlite3DebugPrintf("  estimatedCost=%g\n", p->estimatedCost);
+}
+#else
+#define TRACE_IDX_INPUTS(A)
+#define TRACE_IDX_OUTPUTS(A)
+#endif
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Compute the best index for a virtual table.
+**
+** The best index is computed by the xBestIndex method of the virtual
+** table module.  This routine is really just a wrapper that sets up
+** the sqlite3_index_info structure that is used to communicate with
+** xBestIndex.
+**
+** In a join, this routine might be called multiple times for the
+** same virtual table.  The sqlite3_index_info structure is created
+** and initialized on the first invocation and reused on all subsequent
+** invocations.  The sqlite3_index_info structure is also used when
+** code is generated to access the virtual table.  The whereInfoDelete() 
+** routine takes care of freeing the sqlite3_index_info structure after
+** everybody has finished with it.
+*/
+static double bestVirtualIndex(
+  Parse *pParse,                 /* The parsing context */
+  WhereClause *pWC,              /* The WHERE clause */
+  struct SrcList_item *pSrc,     /* The FROM clause term to search */
+  Bitmask notReady,              /* Mask of cursors that are not available */
+  ExprList *pOrderBy,            /* The order by clause */
+  int orderByUsable,             /* True if we can potential sort */
+  sqlite3_index_info **ppIdxInfo /* Index information passed to xBestIndex */
+){
+  Table *pTab = pSrc->pTab;
+  sqlite3_vtab *pVtab = pTab->pVtab;
+  sqlite3_index_info *pIdxInfo;
+  struct sqlite3_index_constraint *pIdxCons;
+  struct sqlite3_index_orderby *pIdxOrderBy;
+  struct sqlite3_index_constraint_usage *pUsage;
+  WhereTerm *pTerm;
+  int i, j;
+  int nOrderBy;
+  int rc;
+
+  /* If the sqlite3_index_info structure has not been previously
+  ** allocated and initialized for this virtual table, then allocate
+  ** and initialize it now
+  */
+  pIdxInfo = *ppIdxInfo;
+  if( pIdxInfo==0 ){
+    WhereTerm *pTerm;
+    int nTerm;
+    WHERETRACE(("Recomputing index info for %s...\n", pTab->zName));
+
+    /* Count the number of possible WHERE clause constraints referring
+    ** to this virtual table */
+    for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
+      if( pTerm->leftCursor != pSrc->iCursor ) continue;
+      if( (pTerm->eOperator&(pTerm->eOperator-1))==0 );
+      testcase( pTerm->eOperator==WO_IN );
+      testcase( pTerm->eOperator==WO_ISNULL );
+      if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue;
+      nTerm++;
+    }
+
+    /* If the ORDER BY clause contains only columns in the current 
+    ** virtual table then allocate space for the aOrderBy part of
+    ** the sqlite3_index_info structure.
+    */
+    nOrderBy = 0;
+    if( pOrderBy ){
+      for(i=0; i<pOrderBy->nExpr; i++){
+        Expr *pExpr = pOrderBy->a[i].pExpr;
+        if( pExpr->op!=TK_COLUMN || pExpr->iTable!=pSrc->iCursor ) break;
+      }
+      if( i==pOrderBy->nExpr ){
+        nOrderBy = pOrderBy->nExpr;
+      }
+    }
+
+    /* Allocate the sqlite3_index_info structure
+    */
+    pIdxInfo = sqlite3DbMallocZero(pParse->db, sizeof(*pIdxInfo)
+                             + (sizeof(*pIdxCons) + sizeof(*pUsage))*nTerm
+                             + sizeof(*pIdxOrderBy)*nOrderBy );
+    if( pIdxInfo==0 ){
+      sqlite3ErrorMsg(pParse, "out of memory");
+      return 0.0;
+    }
+    *ppIdxInfo = pIdxInfo;
+
+    /* Initialize the structure.  The sqlite3_index_info structure contains
+    ** many fields that are declared "const" to prevent xBestIndex from
+    ** changing them.  We have to do some funky casting in order to
+    ** initialize those fields.
+    */
+    pIdxCons = (struct sqlite3_index_constraint*)&pIdxInfo[1];
+    pIdxOrderBy = (struct sqlite3_index_orderby*)&pIdxCons[nTerm];
+    pUsage = (struct sqlite3_index_constraint_usage*)&pIdxOrderBy[nOrderBy];
+    *(int*)&pIdxInfo->nConstraint = nTerm;
+    *(int*)&pIdxInfo->nOrderBy = nOrderBy;
+    *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint = pIdxCons;
+    *(struct sqlite3_index_orderby**)&pIdxInfo->aOrderBy = pIdxOrderBy;
+    *(struct sqlite3_index_constraint_usage**)&pIdxInfo->aConstraintUsage =
+                                                                     pUsage;
+
+    for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
+      if( pTerm->leftCursor != pSrc->iCursor ) continue;
+      if( (pTerm->eOperator&(pTerm->eOperator-1))==0 );
+      testcase( pTerm->eOperator==WO_IN );
+      testcase( pTerm->eOperator==WO_ISNULL );
+      if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue;
+      pIdxCons[j].iColumn = pTerm->leftColumn;
+      pIdxCons[j].iTermOffset = i;
+      pIdxCons[j].op = pTerm->eOperator;
+      /* The direct assignment in the previous line is possible only because
+      ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The
+      ** following asserts verify this fact. */
+      assert( WO_EQ==SQLITE_INDEX_CONSTRAINT_EQ );
+      assert( WO_LT==SQLITE_INDEX_CONSTRAINT_LT );
+      assert( WO_LE==SQLITE_INDEX_CONSTRAINT_LE );
+      assert( WO_GT==SQLITE_INDEX_CONSTRAINT_GT );
+      assert( WO_GE==SQLITE_INDEX_CONSTRAINT_GE );
+      assert( WO_MATCH==SQLITE_INDEX_CONSTRAINT_MATCH );
+      assert( pTerm->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_MATCH) );
+      j++;
+    }
+    for(i=0; i<nOrderBy; i++){
+      Expr *pExpr = pOrderBy->a[i].pExpr;
+      pIdxOrderBy[i].iColumn = pExpr->iColumn;
+      pIdxOrderBy[i].desc = pOrderBy->a[i].sortOrder;
+    }
+  }
+
+  /* At this point, the sqlite3_index_info structure that pIdxInfo points
+  ** to will have been initialized, either during the current invocation or
+  ** during some prior invocation.  Now we just have to customize the
+  ** details of pIdxInfo for the current invocation and pass it to
+  ** xBestIndex.
+  */
+
+  /* The module name must be defined. Also, by this point there must
+  ** be a pointer to an sqlite3_vtab structure. Otherwise
+  ** sqlite3ViewGetColumnNames() would have picked up the error. 
+  */
+  assert( pTab->azModuleArg && pTab->azModuleArg[0] );
+  assert( pVtab );
+#if 0
+  if( pTab->pVtab==0 ){
+    sqlite3ErrorMsg(pParse, "undefined module %s for table %s",
+        pTab->azModuleArg[0], pTab->zName);
+    return 0.0;
+  }
+#endif
+
+  /* Set the aConstraint[].usable fields and initialize all 
+  ** output variables to zero.
+  **
+  ** aConstraint[].usable is true for constraints where the right-hand
+  ** side contains only references to tables to the left of the current
+  ** table.  In other words, if the constraint is of the form:
+  **
+  **           column = expr
+  **
+  ** and we are evaluating a join, then the constraint on column is 
+  ** only valid if all tables referenced in expr occur to the left
+  ** of the table containing column.
+  **
+  ** The aConstraints[] array contains entries for all constraints
+  ** on the current table.  That way we only have to compute it once
+  ** even though we might try to pick the best index multiple times.
+  ** For each attempt at picking an index, the order of tables in the
+  ** join might be different so we have to recompute the usable flag
+  ** each time.
+  */
+  pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+  pUsage = pIdxInfo->aConstraintUsage;
+  for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
+    j = pIdxCons->iTermOffset;
+    pTerm = &pWC->a[j];
+    pIdxCons->usable =  (pTerm->prereqRight & notReady)==0;
+  }
+  memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
+  if( pIdxInfo->needToFreeIdxStr ){
+    sqlite3_free(pIdxInfo->idxStr);
+  }
+  pIdxInfo->idxStr = 0;
+  pIdxInfo->idxNum = 0;
+  pIdxInfo->needToFreeIdxStr = 0;
+  pIdxInfo->orderByConsumed = 0;
+  pIdxInfo->estimatedCost = SQLITE_BIG_DBL / 2.0;
+  nOrderBy = pIdxInfo->nOrderBy;
+  if( pIdxInfo->nOrderBy && !orderByUsable ){
+    *(int*)&pIdxInfo->nOrderBy = 0;
+  }
+
+  (void)sqlite3SafetyOff(pParse->db);
+  WHERETRACE(("xBestIndex for %s\n", pTab->zName));
+  TRACE_IDX_INPUTS(pIdxInfo);
+  rc = pVtab->pModule->xBestIndex(pVtab, pIdxInfo);
+  TRACE_IDX_OUTPUTS(pIdxInfo);
+  (void)sqlite3SafetyOn(pParse->db);
+
+  if( rc!=SQLITE_OK ){
+    if( rc==SQLITE_NOMEM ){
+      pParse->db->mallocFailed = 1;
+    }else if( !pVtab->zErrMsg ){
+      sqlite3ErrorMsg(pParse, "%s", sqlite3ErrStr(rc));
+    }else{
+      sqlite3ErrorMsg(pParse, "%s", pVtab->zErrMsg);
+    }
+  }
+  sqlite3DbFree(pParse->db, pVtab->zErrMsg);
+  pVtab->zErrMsg = 0;
+
+  for(i=0; i<pIdxInfo->nConstraint; i++){
+    if( !pIdxInfo->aConstraint[i].usable && pUsage[i].argvIndex>0 ){
+      sqlite3ErrorMsg(pParse, 
+          "table %s: xBestIndex returned an invalid plan", pTab->zName);
+      return 0.0;
+    }
+  }
+
+  *(int*)&pIdxInfo->nOrderBy = nOrderBy;
+  return pIdxInfo->estimatedCost;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** Find the best index for accessing a particular table.  Return a pointer
+** to the index, flags that describe how the index should be used, the
+** number of equality constraints, and the "cost" for this index.
+**
+** The lowest cost index wins.  The cost is an estimate of the amount of
+** CPU and disk I/O need to process the request using the selected index.
+** Factors that influence cost include:
+**
+**    *  The estimated number of rows that will be retrieved.  (The
+**       fewer the better.)
+**
+**    *  Whether or not sorting must occur.
+**
+**    *  Whether or not there must be separate lookups in the
+**       index and in the main table.
+**
+*/
+static double bestIndex(
+  Parse *pParse,              /* The parsing context */
+  WhereClause *pWC,           /* The WHERE clause */
+  struct SrcList_item *pSrc,  /* The FROM clause term to search */
+  Bitmask notReady,           /* Mask of cursors that are not available */
+  ExprList *pOrderBy,         /* The order by clause */
+  Index **ppIndex,            /* Make *ppIndex point to the best index */
+  int *pFlags,                /* Put flags describing this choice in *pFlags */
+  int *pnEq                   /* Put the number of == or IN constraints here */
+){
+  WhereTerm *pTerm;
+  Index *bestIdx = 0;         /* Index that gives the lowest cost */
+  double lowestCost;          /* The cost of using bestIdx */
+  int bestFlags = 0;          /* Flags associated with bestIdx */
+  int bestNEq = 0;            /* Best value for nEq */
+  int iCur = pSrc->iCursor;   /* The cursor of the table to be accessed */
+  Index *pProbe;              /* An index we are evaluating */
+  int rev;                    /* True to scan in reverse order */
+  int flags;                  /* Flags associated with pProbe */
+  int nEq;                    /* Number of == or IN constraints */
+  int eqTermMask;             /* Mask of valid equality operators */
+  double cost;                /* Cost of using pProbe */
+
+  WHERETRACE(("bestIndex: tbl=%s notReady=%llx\n", pSrc->pTab->zName, notReady));
+  lowestCost = SQLITE_BIG_DBL;
+  pProbe = pSrc->pTab->pIndex;
+
+  /* If the table has no indices and there are no terms in the where
+  ** clause that refer to the ROWID, then we will never be able to do
+  ** anything other than a full table scan on this table.  We might as
+  ** well put it first in the join order.  That way, perhaps it can be
+  ** referenced by other tables in the join.
+  */
+  if( pProbe==0 &&
+     findTerm(pWC, iCur, -1, 0, WO_EQ|WO_IN|WO_LT|WO_LE|WO_GT|WO_GE,0)==0 &&
+     (pOrderBy==0 || !sortableByRowid(iCur, pOrderBy, pWC->pMaskSet, &rev)) ){
+    *pFlags = 0;
+    *ppIndex = 0;
+    *pnEq = 0;
+    return 0.0;
+  }
+
+  /* Check for a rowid=EXPR or rowid IN (...) constraints
+  */
+  pTerm = findTerm(pWC, iCur, -1, notReady, WO_EQ|WO_IN, 0);
+  if( pTerm ){
+    Expr *pExpr;
+    *ppIndex = 0;
+    bestFlags = WHERE_ROWID_EQ;
+    if( pTerm->eOperator & WO_EQ ){
+      /* Rowid== is always the best pick.  Look no further.  Because only
+      ** a single row is generated, output is always in sorted order */
+      *pFlags = WHERE_ROWID_EQ | WHERE_UNIQUE;
+      *pnEq = 1;
+      WHERETRACE(("... best is rowid\n"));
+      return 0.0;
+    }else if( (pExpr = pTerm->pExpr)->pList!=0 ){
+      /* Rowid IN (LIST): cost is NlogN where N is the number of list
+      ** elements.  */
+      lowestCost = pExpr->pList->nExpr;
+      lowestCost *= estLog(lowestCost);
+    }else{
+      /* Rowid IN (SELECT): cost is NlogN where N is the number of rows
+      ** in the result of the inner select.  We have no way to estimate
+      ** that value so make a wild guess. */
+      lowestCost = 200;
+    }
+    WHERETRACE(("... rowid IN cost: %.9g\n", lowestCost));
+  }
+
+  /* Estimate the cost of a table scan.  If we do not know how many
+  ** entries are in the table, use 1 million as a guess.
+  */
+  cost = pProbe ? pProbe->aiRowEst[0] : 1000000;
+  WHERETRACE(("... table scan base cost: %.9g\n", cost));
+  flags = WHERE_ROWID_RANGE;
+
+  /* Check for constraints on a range of rowids in a table scan.
+  */
+  pTerm = findTerm(pWC, iCur, -1, notReady, WO_LT|WO_LE|WO_GT|WO_GE, 0);
+  if( pTerm ){
+    if( findTerm(pWC, iCur, -1, notReady, WO_LT|WO_LE, 0) ){
+      flags |= WHERE_TOP_LIMIT;
+      cost /= 3;  /* Guess that rowid<EXPR eliminates two-thirds or rows */
+    }
+    if( findTerm(pWC, iCur, -1, notReady, WO_GT|WO_GE, 0) ){
+      flags |= WHERE_BTM_LIMIT;
+      cost /= 3;  /* Guess that rowid>EXPR eliminates two-thirds of rows */
+    }
+    WHERETRACE(("... rowid range reduces cost to %.9g\n", cost));
+  }else{
+    flags = 0;
+  }
+
+  /* If the table scan does not satisfy the ORDER BY clause, increase
+  ** the cost by NlogN to cover the expense of sorting. */
+  if( pOrderBy ){
+    if( sortableByRowid(iCur, pOrderBy, pWC->pMaskSet, &rev) ){
+      flags |= WHERE_ORDERBY|WHERE_ROWID_RANGE;
+      if( rev ){
+        flags |= WHERE_REVERSE;
+      }
+    }else{
+      cost += cost*estLog(cost);
+      WHERETRACE(("... sorting increases cost to %.9g\n", cost));
+    }
+  }
+  if( cost<lowestCost ){
+    lowestCost = cost;
+    bestFlags = flags;
+  }
+
+  /* If the pSrc table is the right table of a LEFT JOIN then we may not
+  ** use an index to satisfy IS NULL constraints on that table.  This is
+  ** because columns might end up being NULL if the table does not match -
+  ** a circumstance which the index cannot help us discover.  Ticket #2177.
+  */
+  if( (pSrc->jointype & JT_LEFT)!=0 ){
+    eqTermMask = WO_EQ|WO_IN;
+  }else{
+    eqTermMask = WO_EQ|WO_IN|WO_ISNULL;
+  }
+
+  /* Look at each index.
+  */
+  for(; pProbe; pProbe=pProbe->pNext){
+    int i;                       /* Loop counter */
+    double inMultiplier = 1;
+
+    WHERETRACE(("... index %s:\n", pProbe->zName));
+
+    /* Count the number of columns in the index that are satisfied
+    ** by x=EXPR constraints or x IN (...) constraints.
+    */
+    flags = 0;
+    for(i=0; i<pProbe->nColumn; i++){
+      int j = pProbe->aiColumn[i];
+      pTerm = findTerm(pWC, iCur, j, notReady, eqTermMask, pProbe);
+      if( pTerm==0 ) break;
+      flags |= WHERE_COLUMN_EQ;
+      if( pTerm->eOperator & WO_IN ){
+        Expr *pExpr = pTerm->pExpr;
+        flags |= WHERE_COLUMN_IN;
+        if( pExpr->pSelect!=0 ){
+          inMultiplier *= 25;
+        }else if( ALWAYS(pExpr->pList) ){
+          inMultiplier *= pExpr->pList->nExpr + 1;
+        }
+      }
+    }
+    cost = pProbe->aiRowEst[i] * inMultiplier * estLog(inMultiplier);
+    nEq = i;
+    if( pProbe->onError!=OE_None && (flags & WHERE_COLUMN_IN)==0
+         && nEq==pProbe->nColumn ){
+      flags |= WHERE_UNIQUE;
+    }
+    WHERETRACE(("...... nEq=%d inMult=%.9g cost=%.9g\n",nEq,inMultiplier,cost));
+
+    /* Look for range constraints
+    */
+    if( nEq<pProbe->nColumn ){
+      int j = pProbe->aiColumn[nEq];
+      pTerm = findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE|WO_GT|WO_GE, pProbe);
+      if( pTerm ){
+        flags |= WHERE_COLUMN_RANGE;
+        if( findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE, pProbe) ){
+          flags |= WHERE_TOP_LIMIT;
+          cost /= 3;
+        }
+        if( findTerm(pWC, iCur, j, notReady, WO_GT|WO_GE, pProbe) ){
+          flags |= WHERE_BTM_LIMIT;
+          cost /= 3;
+        }
+        WHERETRACE(("...... range reduces cost to %.9g\n", cost));
+      }
+    }
+
+    /* Add the additional cost of sorting if that is a factor.
+    */
+    if( pOrderBy ){
+      if( (flags & WHERE_COLUMN_IN)==0 &&
+           isSortingIndex(pParse,pWC->pMaskSet,pProbe,iCur,pOrderBy,nEq,&rev) ){
+        if( flags==0 ){
+          flags = WHERE_COLUMN_RANGE;
+        }
+        flags |= WHERE_ORDERBY;
+        if( rev ){
+          flags |= WHERE_REVERSE;
+        }
+      }else{
+        cost += cost*estLog(cost);
+        WHERETRACE(("...... orderby increases cost to %.9g\n", cost));
+      }
+    }
+
+    /* Check to see if we can get away with using just the index without
+    ** ever reading the table.  If that is the case, then halve the
+    ** cost of this index.
+    */
+    if( flags && pSrc->colUsed < (((Bitmask)1)<<(BMS-1)) ){
+      Bitmask m = pSrc->colUsed;
+      int j;
+      for(j=0; j<pProbe->nColumn; j++){
+        int x = pProbe->aiColumn[j];
+        if( x<BMS-1 ){
+          m &= ~(((Bitmask)1)<<x);
+        }
+      }
+      if( m==0 ){
+        flags |= WHERE_IDX_ONLY;
+        cost /= 2;
+        WHERETRACE(("...... idx-only reduces cost to %.9g\n", cost));
+      }
+    }
+
+    /* If this index has achieved the lowest cost so far, then use it.
+    */
+    if( flags && cost < lowestCost ){
+      bestIdx = pProbe;
+      lowestCost = cost;
+      bestFlags = flags;
+      bestNEq = nEq;
+    }
+  }
+
+  /* Report the best result
+  */
+  *ppIndex = bestIdx;
+  WHERETRACE(("best index is %s, cost=%.9g, flags=%x, nEq=%d\n",
+        bestIdx ? bestIdx->zName : "(none)", lowestCost, bestFlags, bestNEq));
+  *pFlags = bestFlags | eqTermMask;
+  *pnEq = bestNEq;
+  return lowestCost;
+}
+
+
+/*
+** Disable a term in the WHERE clause.  Except, do not disable the term
+** if it controls a LEFT OUTER JOIN and it did not originate in the ON
+** or USING clause of that join.
+**
+** Consider the term t2.z='ok' in the following queries:
+**
+**   (1)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'
+**   (2)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'
+**   (3)  SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'
+**
+** The t2.z='ok' is disabled in the in (2) because it originates
+** in the ON clause.  The term is disabled in (3) because it is not part
+** of a LEFT OUTER JOIN.  In (1), the term is not disabled.
+**
+** Disabling a term causes that term to not be tested in the inner loop
+** of the join.  Disabling is an optimization.  When terms are satisfied
+** by indices, we disable them to prevent redundant tests in the inner
+** loop.  We would get the correct results if nothing were ever disabled,
+** but joins might run a little slower.  The trick is to disable as much
+** as we can without disabling too much.  If we disabled in (1), we'd get
+** the wrong answer.  See ticket #813.
+*/
+static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
+  if( pTerm
+      && ALWAYS((pTerm->flags & TERM_CODED)==0)
+      && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
+  ){
+    pTerm->flags |= TERM_CODED;
+    if( pTerm->iParent>=0 ){
+      WhereTerm *pOther = &pTerm->pWC->a[pTerm->iParent];
+      if( (--pOther->nChild)==0 ){
+        disableTerm(pLevel, pOther);
+      }
+    }
+  }
+}
+
+/*
+** Apply the affinities associated with the first n columns of index
+** pIdx to the values in the n registers starting at base.
+*/
+static void codeApplyAffinity(Parse *pParse, int base, int n, Index *pIdx){
+  if( n>0 ){
+    Vdbe *v = pParse->pVdbe;
+    assert( v!=0 );
+    sqlite3VdbeAddOp2(v, OP_Affinity, base, n);
+    sqlite3IndexAffinityStr(v, pIdx);
+    sqlite3ExprCacheAffinityChange(pParse, base, n);
+  }
+}
+
+
+/*
+** Generate code for a single equality term of the WHERE clause.  An equality
+** term can be either X=expr or X IN (...).   pTerm is the term to be 
+** coded.
+**
+** The current value for the constraint is left in register iReg.
+**
+** For a constraint of the form X=expr, the expression is evaluated and its
+** result is left on the stack.  For constraints of the form X IN (...)
+** this routine sets up a loop that will iterate over all values of X.
+*/
+static int codeEqualityTerm(
+  Parse *pParse,      /* The parsing context */
+  WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */
+  WhereLevel *pLevel, /* When level of the FROM clause we are working on */
+  int iTarget         /* Attempt to leave results in this register */
+){
+  Expr *pX = pTerm->pExpr;
+  Vdbe *v = pParse->pVdbe;
+  int iReg;                  /* Register holding results */
+
+  if( iTarget<=0 ){
+    iReg = iTarget = sqlite3GetTempReg(pParse);
+  }
+  if( pX->op==TK_EQ ){
+    iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
+  }else if( pX->op==TK_ISNULL ){
+    iReg = iTarget;
+    sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
+#ifndef SQLITE_OMIT_SUBQUERY
+  }else{
+    int eType;
+    int iTab;
+    struct InLoop *pIn;
+
+    assert( pX->op==TK_IN );
+    iReg = iTarget;
+    eType = sqlite3FindInIndex(pParse, pX, 0);
+    iTab = pX->iTable;
+    sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
+    VdbeComment((v, "%.*s", pX->span.n, pX->span.z));
+    if( pLevel->nIn==0 ){
+      pLevel->nxt = sqlite3VdbeMakeLabel(v);
+    }
+    pLevel->nIn++;
+    pLevel->aInLoop = sqlite3DbReallocOrFree(pParse->db, pLevel->aInLoop,
+                                    sizeof(pLevel->aInLoop[0])*pLevel->nIn);
+    pIn = pLevel->aInLoop;
+    if( pIn ){
+      pIn += pLevel->nIn - 1;
+      pIn->iCur = iTab;
+      if( eType==IN_INDEX_ROWID ){
+        pIn->topAddr = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iReg);
+      }else{
+        pIn->topAddr = sqlite3VdbeAddOp3(v, OP_Column, iTab, 0, iReg);
+      }
+      sqlite3VdbeAddOp1(v, OP_IsNull, iReg);
+    }else{
+      pLevel->nIn = 0;
+    }
+#endif
+  }
+  disableTerm(pLevel, pTerm);
+  return iReg;
+}
+
+/*
+** Generate code that will evaluate all == and IN constraints for an
+** index.  The values for all constraints are left on the stack.
+**
+** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c).
+** Suppose the WHERE clause is this:  a==5 AND b IN (1,2,3) AND c>5 AND c<10
+** The index has as many as three equality constraints, but in this
+** example, the third "c" value is an inequality.  So only two 
+** constraints are coded.  This routine will generate code to evaluate
+** a==5 and b IN (1,2,3).  The current values for a and b will be left
+** on the stack - a is the deepest and b the shallowest.
+**
+** In the example above nEq==2.  But this subroutine works for any value
+** of nEq including 0.  If nEq==0, this routine is nearly a no-op.
+** The only thing it does is allocate the pLevel->iMem memory cell.
+**
+** This routine always allocates at least one memory cell and puts
+** the address of that memory cell in pLevel->iMem.  The code that
+** calls this routine will use pLevel->iMem to store the termination
+** key value of the loop.  If one or more IN operators appear, then
+** this routine allocates an additional nEq memory cells for internal
+** use.
+*/
+static int codeAllEqualityTerms(
+  Parse *pParse,        /* Parsing context */
+  WhereLevel *pLevel,   /* Which nested loop of the FROM we are coding */
+  WhereClause *pWC,     /* The WHERE clause */
+  Bitmask notReady,     /* Which parts of FROM have not yet been coded */
+  int nExtraReg         /* Number of extra registers to allocate */
+){
+  int nEq = pLevel->nEq;        /* The number of == or IN constraints to code */
+  Vdbe *v = pParse->pVdbe;      /* The virtual machine under construction */
+  Index *pIdx = pLevel->pIdx;   /* The index being used for this loop */
+  int iCur = pLevel->iTabCur;   /* The cursor of the table */
+  WhereTerm *pTerm;             /* A single constraint term */
+  int j;                        /* Loop counter */
+  int regBase;                  /* Base register */
+
+  /* Figure out how many memory cells we will need then allocate them.
+  ** We always need at least one used to store the loop terminator
+  ** value.  If there are IN operators we'll need one for each == or
+  ** IN constraint.
+  */
+  pLevel->iMem = pParse->nMem + 1;
+  regBase = pParse->nMem + 2;
+  pParse->nMem += pLevel->nEq + 2 + nExtraReg;
+
+  /* Evaluate the equality constraints
+  */
+  assert( pIdx->nColumn>=nEq );
+  for(j=0; j<nEq; j++){
+    int r1;
+    int k = pIdx->aiColumn[j];
+    pTerm = findTerm(pWC, iCur, k, notReady, pLevel->flags, pIdx);
+    if( NEVER(pTerm==0) ) break;
+    assert( (pTerm->flags & TERM_CODED)==0 );
+    r1 = codeEqualityTerm(pParse, pTerm, pLevel, regBase+j);
+    if( r1!=regBase+j ){
+      sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
+    }
+    testcase( pTerm->eOperator & WO_ISNULL );
+    testcase( pTerm->eOperator & WO_IN );
+    if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
+      sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->brk);
+    }
+  }
+  return regBase;
+}
+
+#if defined(SQLITE_TEST)
+/*
+** The following variable holds a text description of query plan generated
+** by the most recent call to sqlite3WhereBegin().  Each call to WhereBegin
+** overwrites the previous.  This information is used for testing and
+** analysis only.
+*/
+char sqlite3_query_plan[BMS*2*40];  /* Text of the join */
+static int nQPlan = 0;              /* Next free slow in _query_plan[] */
+
+#endif /* SQLITE_TEST */
+
+
+/*
+** Free a WhereInfo structure
+*/
+static void whereInfoFree(WhereInfo *pWInfo){
+  if( pWInfo ){
+    int i;
+    sqlite3 *db = pWInfo->pParse->db;
+    for(i=0; i<pWInfo->nLevel; i++){
+      sqlite3_index_info *pInfo = pWInfo->a[i].pIdxInfo;
+      if( pInfo ){
+        assert( pInfo->needToFreeIdxStr==0 );
+        sqlite3DbFree(db, pInfo);
+      }
+    }
+    sqlite3DbFree(db, pWInfo);
+  }
+}
+
+
+/*
+** Generate the beginning of the loop used for WHERE clause processing.
+** The return value is a pointer to an opaque structure that contains
+** information needed to terminate the loop.  Later, the calling routine
+** should invoke sqlite3WhereEnd() with the return value of this function
+** in order to complete the WHERE clause processing.
+**
+** If an error occurs, this routine returns NULL.
+**
+** The basic idea is to do a nested loop, one loop for each table in
+** the FROM clause of a select.  (INSERT and UPDATE statements are the
+** same as a SELECT with only a single table in the FROM clause.)  For
+** example, if the SQL is this:
+**
+**       SELECT * FROM t1, t2, t3 WHERE ...;
+**
+** Then the code generated is conceptually like the following:
+**
+**      foreach row1 in t1 do       \    Code generated
+**        foreach row2 in t2 do      |-- by sqlite3WhereBegin()
+**          foreach row3 in t3 do   /
+**            ...
+**          end                     \    Code generated
+**        end                        |-- by sqlite3WhereEnd()
+**      end                         /
+**
+** Note that the loops might not be nested in the order in which they
+** appear in the FROM clause if a different order is better able to make
+** use of indices.  Note also that when the IN operator appears in
+** the WHERE clause, it might result in additional nested loops for
+** scanning through all values on the right-hand side of the IN.
+**
+** There are Btree cursors associated with each table.  t1 uses cursor
+** number pTabList->a[0].iCursor.  t2 uses the cursor pTabList->a[1].iCursor.
+** And so forth.  This routine generates code to open those VDBE cursors
+** and sqlite3WhereEnd() generates the code to close them.
+**
+** The code that sqlite3WhereBegin() generates leaves the cursors named
+** in pTabList pointing at their appropriate entries.  The [...] code
+** can use OP_Column and OP_Rowid opcodes on these cursors to extract
+** data from the various tables of the loop.
+**
+** If the WHERE clause is empty, the foreach loops must each scan their
+** entire tables.  Thus a three-way join is an O(N^3) operation.  But if
+** the tables have indices and there are terms in the WHERE clause that
+** refer to those indices, a complete table scan can be avoided and the
+** code will run much faster.  Most of the work of this routine is checking
+** to see if there are indices that can be used to speed up the loop.
+**
+** Terms of the WHERE clause are also used to limit which rows actually
+** make it to the "..." in the middle of the loop.  After each "foreach",
+** terms of the WHERE clause that use only terms in that loop and outer
+** loops are evaluated and if false a jump is made around all subsequent
+** inner loops (or around the "..." if the test occurs within the inner-
+** most loop)
+**
+** OUTER JOINS
+**
+** An outer join of tables t1 and t2 is conceptally coded as follows:
+**
+**    foreach row1 in t1 do
+**      flag = 0
+**      foreach row2 in t2 do
+**        start:
+**          ...
+**          flag = 1
+**      end
+**      if flag==0 then
+**        move the row2 cursor to a null row
+**        goto start
+**      fi
+**    end
+**
+** ORDER BY CLAUSE PROCESSING
+**
+** *ppOrderBy is a pointer to the ORDER BY clause of a SELECT statement,
+** if there is one.  If there is no ORDER BY clause or if this routine
+** is called from an UPDATE or DELETE statement, then ppOrderBy is NULL.
+**
+** If an index can be used so that the natural output order of the table
+** scan is correct for the ORDER BY clause, then that index is used and
+** *ppOrderBy is set to NULL.  This is an optimization that prevents an
+** unnecessary sort of the result set if an index appropriate for the
+** ORDER BY clause already exists.
+**
+** If the where clause loops cannot be arranged to provide the correct
+** output order, then the *ppOrderBy is unchanged.
+*/
+WhereInfo *sqlite3WhereBegin(
+  Parse *pParse,        /* The parser context */
+  SrcList *pTabList,    /* A list of all tables to be scanned */
+  Expr *pWhere,         /* The WHERE clause */
+  ExprList **ppOrderBy, /* An ORDER BY clause, or NULL */
+  u8 wflags             /* One of the WHERE_* flags defined in sqliteInt.h */
+){
+  int i;                     /* Loop counter */
+  WhereInfo *pWInfo;         /* Will become the return value of this function */
+  Vdbe *v = pParse->pVdbe;   /* The virtual database engine */
+  int brk, cont = 0;         /* Addresses used during code generation */
+  Bitmask notReady;          /* Cursors that are not yet positioned */
+  WhereTerm *pTerm;          /* A single term in the WHERE clause */
+  ExprMaskSet maskSet;       /* The expression mask set */
+  WhereClause wc;            /* The WHERE clause is divided into these terms */
+  struct SrcList_item *pTabItem;  /* A single entry from pTabList */
+  WhereLevel *pLevel;             /* A single level in the pWInfo list */
+  int iFrom;                      /* First unused FROM clause element */
+  int andFlags;              /* AND-ed combination of all wc.a[].flags */
+  sqlite3 *db;               /* Database connection */
+  ExprList *pOrderBy = 0;
+
+  /* The number of tables in the FROM clause is limited by the number of
+  ** bits in a Bitmask 
+  */
+  if( pTabList->nSrc>BMS ){
+    sqlite3ErrorMsg(pParse, "at most %d tables in a join", BMS);
+    return 0;
+  }
+
+  if( ppOrderBy ){
+    pOrderBy = *ppOrderBy;
+  }
+
+  /* Split the WHERE clause into separate subexpressions where each
+  ** subexpression is separated by an AND operator.
+  */
+  initMaskSet(&maskSet);
+  whereClauseInit(&wc, pParse, &maskSet);
+  sqlite3ExprCodeConstants(pParse, pWhere);
+  whereSplit(&wc, pWhere, TK_AND);
+    
+  /* Allocate and initialize the WhereInfo structure that will become the
+  ** return value.
+  */
+  db = pParse->db;
+  pWInfo = sqlite3DbMallocZero(db,  
+                      sizeof(WhereInfo) + pTabList->nSrc*sizeof(WhereLevel));
+  if( db->mallocFailed ){
+    goto whereBeginNoMem;
+  }
+  pWInfo->nLevel = pTabList->nSrc;
+  pWInfo->pParse = pParse;
+  pWInfo->pTabList = pTabList;
+  pWInfo->iBreak = sqlite3VdbeMakeLabel(v);
+
+  /* Special case: a WHERE clause that is constant.  Evaluate the
+  ** expression and either jump over all of the code or fall thru.
+  */
+  if( pWhere && (pTabList->nSrc==0 || sqlite3ExprIsConstantNotJoin(pWhere)) ){
+    sqlite3ExprIfFalse(pParse, pWhere, pWInfo->iBreak, SQLITE_JUMPIFNULL);
+    pWhere = 0;
+  }
+
+  /* Assign a bit from the bitmask to every term in the FROM clause.
+  **
+  ** When assigning bitmask values to FROM clause cursors, it must be
+  ** the case that if X is the bitmask for the N-th FROM clause term then
+  ** the bitmask for all FROM clause terms to the left of the N-th term
+  ** is (X-1).   An expression from the ON clause of a LEFT JOIN can use
+  ** its Expr.iRightJoinTable value to find the bitmask of the right table
+  ** of the join.  Subtracting one from the right table bitmask gives a
+  ** bitmask for all tables to the left of the join.  Knowing the bitmask
+  ** for all tables to the left of a left join is important.  Ticket #3015.
+  */
+  for(i=0; i<pTabList->nSrc; i++){
+    createMask(&maskSet, pTabList->a[i].iCursor);
+  }
+#ifndef NDEBUG
+  {
+    Bitmask toTheLeft = 0;
+    for(i=0; i<pTabList->nSrc; i++){
+      Bitmask m = getMask(&maskSet, pTabList->a[i].iCursor);
+      assert( (m-1)==toTheLeft );
+      toTheLeft |= m;
+    }
+  }
+#endif
+
+  /* Analyze all of the subexpressions.  Note that exprAnalyze() might
+  ** add new virtual terms onto the end of the WHERE clause.  We do not
+  ** want to analyze these virtual terms, so start analyzing at the end
+  ** and work forward so that the added virtual terms are never processed.
+  */
+  exprAnalyzeAll(pTabList, &wc);
+  if( db->mallocFailed ){
+    goto whereBeginNoMem;
+  }
+
+  /* Chose the best index to use for each table in the FROM clause.
+  **
+  ** This loop fills in the following fields:
+  **
+  **   pWInfo->a[].pIdx      The index to use for this level of the loop.
+  **   pWInfo->a[].flags     WHERE_xxx flags associated with pIdx
+  **   pWInfo->a[].nEq       The number of == and IN constraints
+  **   pWInfo->a[].iFrom     When term of the FROM clause is being coded
+  **   pWInfo->a[].iTabCur   The VDBE cursor for the database table
+  **   pWInfo->a[].iIdxCur   The VDBE cursor for the index
+  **
+  ** This loop also figures out the nesting order of tables in the FROM
+  ** clause.
+  */
+  notReady = ~(Bitmask)0;
+  pTabItem = pTabList->a;
+  pLevel = pWInfo->a;
+  andFlags = ~0;
+  WHERETRACE(("*** Optimizer Start ***\n"));
+  for(i=iFrom=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
+    Index *pIdx;                /* Index for FROM table at pTabItem */
+    int flags;                  /* Flags asssociated with pIdx */
+    int nEq;                    /* Number of == or IN constraints */
+    double cost;                /* The cost for pIdx */
+    int j;                      /* For looping over FROM tables */
+    Index *pBest = 0;           /* The best index seen so far */
+    int bestFlags = 0;          /* Flags associated with pBest */
+    int bestNEq = 0;            /* nEq associated with pBest */
+    double lowestCost;          /* Cost of the pBest */
+    int bestJ = 0;              /* The value of j */
+    Bitmask m;                  /* Bitmask value for j or bestJ */
+    int once = 0;               /* True when first table is seen */
+    sqlite3_index_info *pIndex; /* Current virtual index */
+
+    lowestCost = SQLITE_BIG_DBL;
+    for(j=iFrom, pTabItem=&pTabList->a[j]; j<pTabList->nSrc; j++, pTabItem++){
+      int doNotReorder;  /* True if this table should not be reordered */
+
+      doNotReorder =  (pTabItem->jointype & (JT_LEFT|JT_CROSS))!=0;
+      if( once && doNotReorder ) break;
+      m = getMask(&maskSet, pTabItem->iCursor);
+      if( (m & notReady)==0 ){
+        if( j==iFrom ) iFrom++;
+        continue;
+      }
+      assert( pTabItem->pTab );
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+      if( IsVirtual(pTabItem->pTab) ){
+        sqlite3_index_info **ppIdxInfo = &pWInfo->a[j].pIdxInfo;
+        cost = bestVirtualIndex(pParse, &wc, pTabItem, notReady,
+                                ppOrderBy ? *ppOrderBy : 0, i==0,
+                                ppIdxInfo);
+        flags = WHERE_VIRTUALTABLE;
+        pIndex = *ppIdxInfo;
+        if( pIndex && pIndex->orderByConsumed ){
+          flags = WHERE_VIRTUALTABLE | WHERE_ORDERBY;
+        }
+        pIdx = 0;
+        nEq = 0;
+        if( (SQLITE_BIG_DBL/2.0)<cost ){
+          /* The cost is not allowed to be larger than SQLITE_BIG_DBL (the
+          ** inital value of lowestCost in this loop. If it is, then
+          ** the (cost<lowestCost) test below will never be true and
+          ** pLevel->pBestIdx never set.
+          */ 
+          cost = (SQLITE_BIG_DBL/2.0);
+        }
+      }else 
+#endif
+      {
+        cost = bestIndex(pParse, &wc, pTabItem, notReady,
+                         (i==0 && ppOrderBy) ? *ppOrderBy : 0,
+                         &pIdx, &flags, &nEq);
+        pIndex = 0;
+      }
+      if( cost<lowestCost ){
+        once = 1;
+        lowestCost = cost;
+        pBest = pIdx;
+        bestFlags = flags;
+        bestNEq = nEq;
+        bestJ = j;
+        pLevel->pBestIdx = pIndex;
+      }
+      if( doNotReorder ) break;
+    }
+    WHERETRACE(("*** Optimizer selects table %d for loop %d\n", bestJ,
+           pLevel-pWInfo->a));
+    if( (bestFlags & WHERE_ORDERBY)!=0 ){
+      *ppOrderBy = 0;
+    }
+    andFlags &= bestFlags;
+    pLevel->flags = bestFlags;
+    pLevel->pIdx = pBest;
+    pLevel->nEq = bestNEq;
+    pLevel->aInLoop = 0;
+    pLevel->nIn = 0;
+    if( pBest ){
+      pLevel->iIdxCur = pParse->nTab++;
+    }else{
+      pLevel->iIdxCur = -1;
+    }
+    notReady &= ~getMask(&maskSet, pTabList->a[bestJ].iCursor);
+    pLevel->iFrom = bestJ;
+  }
+  WHERETRACE(("*** Optimizer Finished ***\n"));
+
+  /* If the total query only selects a single row, then the ORDER BY
+  ** clause is irrelevant.
+  */
+  if( (andFlags & WHERE_UNIQUE)!=0 && ppOrderBy ){
+    *ppOrderBy = 0;
+  }
+
+  /* If the caller is an UPDATE or DELETE statement that is requesting
+  ** to use a one-pass algorithm, determine if this is appropriate.
+  ** The one-pass algorithm only works if the WHERE clause constraints
+  ** the statement to update a single row.
+  */
+  assert( (wflags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
+  if( (wflags & WHERE_ONEPASS_DESIRED)!=0 && (andFlags & WHERE_UNIQUE)!=0 ){
+    pWInfo->okOnePass = 1;
+    pWInfo->a[0].flags &= ~WHERE_IDX_ONLY;
+  }
+
+  /* Open all tables in the pTabList and any indices selected for
+  ** searching those tables.
+  */
+  sqlite3CodeVerifySchema(pParse, -1); /* Insert the cookie verifier Goto */
+  for(i=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
+    Table *pTab;     /* Table to open */
+    Index *pIx;      /* Index used to access pTab (if any) */
+    int iDb;         /* Index of database containing table/index */
+    int iIdxCur = pLevel->iIdxCur;
+
+#ifndef SQLITE_OMIT_EXPLAIN
+    if( pParse->explain==2 ){
+      char *zMsg;
+      struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
+      zMsg = sqlite3MPrintf(db, "TABLE %s", pItem->zName);
+      if( pItem->zAlias ){
+        zMsg = sqlite3MAppendf(db, zMsg, "%s AS %s", zMsg, pItem->zAlias);
+      }
+      if( (pIx = pLevel->pIdx)!=0 ){
+        zMsg = sqlite3MAppendf(db, zMsg, "%s WITH INDEX %s", zMsg, pIx->zName);
+      }else if( pLevel->flags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
+        zMsg = sqlite3MAppendf(db, zMsg, "%s USING PRIMARY KEY", zMsg);
+      }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+      else if( pLevel->pBestIdx ){
+        sqlite3_index_info *pBestIdx = pLevel->pBestIdx;
+        zMsg = sqlite3MAppendf(db, zMsg, "%s VIRTUAL TABLE INDEX %d:%s", zMsg,
+                    pBestIdx->idxNum, pBestIdx->idxStr);
+      }
+#endif
+      if( pLevel->flags & WHERE_ORDERBY ){
+        zMsg = sqlite3MAppendf(db, zMsg, "%s ORDER BY", zMsg);
+      }
+      sqlite3VdbeAddOp4(v, OP_Explain, i, pLevel->iFrom, 0, zMsg, P4_DYNAMIC);
+    }
+#endif /* SQLITE_OMIT_EXPLAIN */
+    pTabItem = &pTabList->a[pLevel->iFrom];
+    pTab = pTabItem->pTab;
+    iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+    if( pTab->isEphem || pTab->pSelect ) continue;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( pLevel->pBestIdx ){
+      int iCur = pTabItem->iCursor;
+      sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0,
+                        (const char*)pTab->pVtab, P4_VTAB);
+    }else
+#endif
+    if( (pLevel->flags & WHERE_IDX_ONLY)==0 ){
+      int op = pWInfo->okOnePass ? OP_OpenWrite : OP_OpenRead;
+      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
+      if( !pWInfo->okOnePass && pTab->nCol<(sizeof(Bitmask)*8) ){
+        Bitmask b = pTabItem->colUsed;
+        int n = 0;
+        for(; b; b=b>>1, n++){}
+        sqlite3VdbeChangeP2(v, sqlite3VdbeCurrentAddr(v)-2, n);
+        assert( n<=pTab->nCol );
+      }
+    }else{
+      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
+    }
+    pLevel->iTabCur = pTabItem->iCursor;
+    if( (pIx = pLevel->pIdx)!=0 ){
+      KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx);
+      assert( pIx->pSchema==pTab->pSchema );
+      sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pIx->nColumn+1);
+      sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIx->tnum, iDb,
+                        (char*)pKey, P4_KEYINFO_HANDOFF);
+      VdbeComment((v, "%s", pIx->zName));
+    }
+    sqlite3CodeVerifySchema(pParse, iDb);
+  }
+  pWInfo->iTop = sqlite3VdbeCurrentAddr(v);
+
+  /* Generate the code to do the search.  Each iteration of the for
+  ** loop below generates code for a single nested loop of the VM
+  ** program.
+  */
+  notReady = ~(Bitmask)0;
+  for(i=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
+    int j;
+    int iCur = pTabItem->iCursor;  /* The VDBE cursor for the table */
+    Index *pIdx;       /* The index we will be using */
+    int nxt;           /* Where to jump to continue with the next IN case */
+    int iIdxCur;       /* The VDBE cursor for the index */
+    int omitTable;     /* True if we use the index only */
+    int bRev;          /* True if we need to scan in reverse order */
+
+    pTabItem = &pTabList->a[pLevel->iFrom];
+    iCur = pTabItem->iCursor;
+    pIdx = pLevel->pIdx;
+    iIdxCur = pLevel->iIdxCur;
+    bRev = (pLevel->flags & WHERE_REVERSE)!=0;
+    omitTable = (pLevel->flags & WHERE_IDX_ONLY)!=0;
+
+    /* Create labels for the "break" and "continue" instructions
+    ** for the current loop.  Jump to brk to break out of a loop.
+    ** Jump to cont to go immediately to the next iteration of the
+    ** loop.
+    **
+    ** When there is an IN operator, we also have a "nxt" label that
+    ** means to continue with the next IN value combination.  When
+    ** there are no IN operators in the constraints, the "nxt" label
+    ** is the same as "brk".
+    */
+    brk = pLevel->brk = pLevel->nxt = sqlite3VdbeMakeLabel(v);
+    cont = pLevel->cont = sqlite3VdbeMakeLabel(v);
+
+    /* If this is the right table of a LEFT OUTER JOIN, allocate and
+    ** initialize a memory cell that records if this table matches any
+    ** row of the left table of the join.
+    */
+    if( pLevel->iFrom>0 && (pTabItem[0].jointype & JT_LEFT)!=0 ){
+      pLevel->iLeftJoin = ++pParse->nMem;
+      sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
+      VdbeComment((v, "init LEFT JOIN no-match flag"));
+    }
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( pLevel->pBestIdx ){
+      /* Case 0:  The table is a virtual-table.  Use the VFilter and VNext
+      **          to access the data.
+      */
+      int j;
+      int iReg;   /* P3 Value for OP_VFilter */
+      sqlite3_index_info *pBestIdx = pLevel->pBestIdx;
+      int nConstraint = pBestIdx->nConstraint;
+      struct sqlite3_index_constraint_usage *aUsage =
+                                                  pBestIdx->aConstraintUsage;
+      const struct sqlite3_index_constraint *aConstraint =
+                                                  pBestIdx->aConstraint;
+
+      iReg = sqlite3GetTempRange(pParse, nConstraint+2);
+      pParse->disableColCache++;
+      for(j=1; j<=nConstraint; j++){
+        int k;
+        for(k=0; k<nConstraint; k++){
+          if( aUsage[k].argvIndex==j ){
+            int iTerm = aConstraint[k].iTermOffset;
+            assert( pParse->disableColCache );
+            sqlite3ExprCode(pParse, wc.a[iTerm].pExpr->pRight, iReg+j+1);
+            break;
+          }
+        }
+        if( k==nConstraint ) break;
+      }
+      assert( pParse->disableColCache );
+      pParse->disableColCache--;
+      sqlite3VdbeAddOp2(v, OP_Integer, pBestIdx->idxNum, iReg);
+      sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1);
+      sqlite3VdbeAddOp4(v, OP_VFilter, iCur, brk, iReg, pBestIdx->idxStr,
+                        pBestIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC);
+      sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
+      pBestIdx->needToFreeIdxStr = 0;
+      for(j=0; j<nConstraint; j++){
+        if( aUsage[j].omit ){
+          int iTerm = aConstraint[j].iTermOffset;
+          disableTerm(pLevel, &wc.a[iTerm]);
+        }
+      }
+      pLevel->op = OP_VNext;
+      pLevel->p1 = iCur;
+      pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+    }else
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+    if( pLevel->flags & WHERE_ROWID_EQ ){
+      /* Case 1:  We can directly reference a single row using an
+      **          equality comparison against the ROWID field.  Or
+      **          we reference multiple rows using a "rowid IN (...)"
+      **          construct.
+      */
+      int r1;
+      pTerm = findTerm(&wc, iCur, -1, notReady, WO_EQ|WO_IN, 0);
+      assert( pTerm!=0 );
+      assert( pTerm->pExpr!=0 );
+      assert( pTerm->leftCursor==iCur );
+      assert( omitTable==0 );
+      r1 = codeEqualityTerm(pParse, pTerm, pLevel, 0);
+      nxt = pLevel->nxt;
+      sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, nxt);
+      sqlite3VdbeAddOp3(v, OP_NotExists, iCur, nxt, r1);
+      VdbeComment((v, "pk"));
+      pLevel->op = OP_Noop;
+    }else if( pLevel->flags & WHERE_ROWID_RANGE ){
+      /* Case 2:  We have an inequality comparison against the ROWID field.
+      */
+      int testOp = OP_Noop;
+      int start;
+      WhereTerm *pStart, *pEnd;
+
+      assert( omitTable==0 );
+      pStart = findTerm(&wc, iCur, -1, notReady, WO_GT|WO_GE, 0);
+      pEnd = findTerm(&wc, iCur, -1, notReady, WO_LT|WO_LE, 0);
+      if( bRev ){
+        pTerm = pStart;
+        pStart = pEnd;
+        pEnd = pTerm;
+      }
+      if( pStart ){
+        Expr *pX;
+        int r1, regFree1;
+        pX = pStart->pExpr;
+        assert( pX!=0 );
+        assert( pStart->leftCursor==iCur );
+        r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &regFree1);
+        sqlite3VdbeAddOp3(v, OP_ForceInt, r1, brk, 
+                             pX->op==TK_LE || pX->op==TK_GT);
+        sqlite3VdbeAddOp3(v, bRev ? OP_MoveLt : OP_MoveGe, iCur, brk, r1);
+        VdbeComment((v, "pk"));
+        sqlite3ReleaseTempReg(pParse, regFree1);
+        disableTerm(pLevel, pStart);
+      }else{
+        sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, brk);
+      }
+      if( pEnd ){
+        Expr *pX;
+        pX = pEnd->pExpr;
+        assert( pX!=0 );
+        assert( pEnd->leftCursor==iCur );
+        pLevel->iMem = ++pParse->nMem;
+        sqlite3ExprCode(pParse, pX->pRight, pLevel->iMem);
+        if( pX->op==TK_LT || pX->op==TK_GT ){
+          testOp = bRev ? OP_Le : OP_Ge;
+        }else{
+          testOp = bRev ? OP_Lt : OP_Gt;
+        }
+        disableTerm(pLevel, pEnd);
+      }
+      start = sqlite3VdbeCurrentAddr(v);
+      pLevel->op = bRev ? OP_Prev : OP_Next;
+      pLevel->p1 = iCur;
+      pLevel->p2 = start;
+      if( testOp!=OP_Noop ){
+        int r1 = sqlite3GetTempReg(pParse);
+        sqlite3VdbeAddOp2(v, OP_Rowid, iCur, r1);
+        /* sqlite3VdbeAddOp2(v, OP_SCopy, pLevel->iMem, 0); */
+        sqlite3VdbeAddOp3(v, testOp, pLevel->iMem, brk, r1);
+        sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
+        sqlite3ReleaseTempReg(pParse, r1);
+      }
+    }else if( pLevel->flags & (WHERE_COLUMN_RANGE|WHERE_COLUMN_EQ) ){
+      /* Case 3: A scan using an index.
+      **
+      **         The WHERE clause may contain zero or more equality 
+      **         terms ("==" or "IN" operators) that refer to the N
+      **         left-most columns of the index. It may also contain
+      **         inequality constraints (>, <, >= or <=) on the indexed
+      **         column that immediately follows the N equalities. Only 
+      **         the right-most column can be an inequality - the rest must
+      **         use the "==" and "IN" operators. For example, if the 
+      **         index is on (x,y,z), then the following clauses are all 
+      **         optimized:
+      **
+      **            x=5
+      **            x=5 AND y=10
+      **            x=5 AND y<10
+      **            x=5 AND y>5 AND y<10
+      **            x=5 AND y=5 AND z<=10
+      **
+      **         The z<10 term of the following cannot be used, only
+      **         the x=5 term:
+      **
+      **            x=5 AND z<10
+      **
+      **         N may be zero if there are inequality constraints.
+      **         If there are no inequality constraints, then N is at
+      **         least one.
+      **
+      **         This case is also used when there are no WHERE clause
+      **         constraints but an index is selected anyway, in order
+      **         to force the output order to conform to an ORDER BY.
+      */  
+      int aStartOp[] = {
+        0,
+        0,
+        OP_Rewind,           /* 2: (!start_constraints && startEq &&  !bRev) */
+        OP_Last,             /* 3: (!start_constraints && startEq &&   bRev) */
+        OP_MoveGt,           /* 4: (start_constraints  && !startEq && !bRev) */
+        OP_MoveLt,           /* 5: (start_constraints  && !startEq &&  bRev) */
+        OP_MoveGe,           /* 6: (start_constraints  &&  startEq && !bRev) */
+        OP_MoveLe            /* 7: (start_constraints  &&  startEq &&  bRev) */
+      };
+      int aEndOp[] = {
+        OP_Noop,             /* 0: (!end_constraints) */
+        OP_IdxGE,            /* 1: (end_constraints && !bRev) */
+        OP_IdxLT             /* 2: (end_constraints && bRev) */
+      };
+      int nEq = pLevel->nEq;
+      int isMinQuery = 0;          /* If this is an optimized SELECT min(x).. */
+      int regBase;                 /* Base register holding constraint values */
+      int r1;                      /* Temp register */
+      WhereTerm *pRangeStart = 0;  /* Inequality constraint at range start */
+      WhereTerm *pRangeEnd = 0;    /* Inequality constraint at range end */
+      int startEq;                 /* True if range start uses ==, >= or <= */
+      int endEq;                   /* True if range end uses ==, >= or <= */
+      int start_constraints;       /* Start of range is constrained */
+      int k = pIdx->aiColumn[nEq]; /* Column for inequality constraints */
+      int nConstraint;             /* Number of constraint terms */
+      int op;
+
+      /* Generate code to evaluate all constraint terms using == or IN
+      ** and store the values of those terms in an array of registers
+      ** starting at regBase.
+      */
+      regBase = codeAllEqualityTerms(pParse, pLevel, &wc, notReady, 2);
+      nxt = pLevel->nxt;
+
+      /* If this loop satisfies a sort order (pOrderBy) request that 
+      ** was passed to this function to implement a "SELECT min(x) ..." 
+      ** query, then the caller will only allow the loop to run for
+      ** a single iteration. This means that the first row returned
+      ** should not have a NULL value stored in 'x'. If column 'x' is
+      ** the first one after the nEq equality constraints in the index,
+      ** this requires some special handling.
+      */
+      if( (wflags&WHERE_ORDERBY_MIN)!=0
+       && (pLevel->flags&WHERE_ORDERBY)
+       && (pIdx->nColumn>nEq)
+      ){
+        assert( pOrderBy->nExpr==1 );
+        assert( pOrderBy->a[0].pExpr->iColumn==pIdx->aiColumn[nEq] );
+        isMinQuery = 1;
+      }
+
+      /* Find any inequality constraint terms for the start and end 
+      ** of the range. 
+      */
+      if( pLevel->flags & WHERE_TOP_LIMIT ){
+        pRangeEnd = findTerm(&wc, iCur, k, notReady, (WO_LT|WO_LE), pIdx);
+      }
+      if( pLevel->flags & WHERE_BTM_LIMIT ){
+        pRangeStart = findTerm(&wc, iCur, k, notReady, (WO_GT|WO_GE), pIdx);
+      }
+
+      /* If we are doing a reverse order scan on an ascending index, or
+      ** a forward order scan on a descending index, interchange the 
+      ** start and end terms (pRangeStart and pRangeEnd).
+      */
+      if( bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC) ){
+        SWAP(WhereTerm *, pRangeEnd, pRangeStart);
+      }
+
+      testcase( pRangeStart && pRangeStart->eOperator & WO_LE );
+      testcase( pRangeStart && pRangeStart->eOperator & WO_GE );
+      testcase( pRangeEnd && pRangeEnd->eOperator & WO_LE );
+      testcase( pRangeEnd && pRangeEnd->eOperator & WO_GE );
+      startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
+      endEq =   !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
+      start_constraints = pRangeStart || nEq>0;
+
+      /* Seek the index cursor to the start of the range. */
+      nConstraint = nEq;
+      if( pRangeStart ){
+        int dcc = pParse->disableColCache;
+        if( pRangeEnd ){
+          pParse->disableColCache++;
+        }
+        sqlite3ExprCode(pParse, pRangeStart->pExpr->pRight, regBase+nEq);
+        pParse->disableColCache = dcc;
+        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, nxt);
+        nConstraint++;
+      }else if( isMinQuery ){
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
+        nConstraint++;
+        startEq = 0;
+        start_constraints = 1;
+      }
+      codeApplyAffinity(pParse, regBase, nConstraint, pIdx);
+      op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
+      assert( op!=0 );
+      testcase( op==OP_Rewind );
+      testcase( op==OP_Last );
+      testcase( op==OP_MoveGt );
+      testcase( op==OP_MoveGe );
+      testcase( op==OP_MoveLe );
+      testcase( op==OP_MoveLt );
+      sqlite3VdbeAddOp4(v, op, iIdxCur, nxt, regBase, 
+                        SQLITE_INT_TO_PTR(nConstraint), P4_INT32);
+
+      /* Load the value for the inequality constraint at the end of the
+      ** range (if any).
+      */
+      nConstraint = nEq;
+      if( pRangeEnd ){
+        sqlite3ExprCode(pParse, pRangeEnd->pExpr->pRight, regBase+nEq);
+        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, nxt);
+        codeApplyAffinity(pParse, regBase, nEq+1, pIdx);
+        nConstraint++;
+      }
+
+      /* Top of the loop body */
+      pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+
+      /* Check if the index cursor is past the end of the range. */
+      op = aEndOp[(pRangeEnd || nEq) * (1 + bRev)];
+      testcase( op==OP_Noop );
+      testcase( op==OP_IdxGE );
+      testcase( op==OP_IdxLT );
+      sqlite3VdbeAddOp4(v, op, iIdxCur, nxt, regBase,
+                        SQLITE_INT_TO_PTR(nConstraint), P4_INT32);
+      sqlite3VdbeChangeP5(v, endEq!=bRev);
+
+      /* If there are inequality constraints, check that the value
+      ** of the table column that the inequality contrains is not NULL.
+      ** If it is, jump to the next iteration of the loop.
+      */
+      r1 = sqlite3GetTempReg(pParse);
+      testcase( pLevel->flags & WHERE_BTM_LIMIT );
+      testcase( pLevel->flags & WHERE_TOP_LIMIT );
+      if( pLevel->flags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT) ){
+        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1);
+        sqlite3VdbeAddOp2(v, OP_IsNull, r1, cont);
+      }
+
+      /* Seek the table cursor, if required */
+      if( !omitTable ){
+        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, r1);
+        sqlite3VdbeAddOp3(v, OP_MoveGe, iCur, 0, r1);  /* Deferred seek */
+      }
+      sqlite3ReleaseTempReg(pParse, r1);
+
+      /* Record the instruction used to terminate the loop. Disable 
+      ** WHERE clause terms made redundant by the index range scan.
+      */
+      pLevel->op = bRev ? OP_Prev : OP_Next;
+      pLevel->p1 = iIdxCur;
+      disableTerm(pLevel, pRangeStart);
+      disableTerm(pLevel, pRangeEnd);
+    }else{
+      /* Case 4:  There is no usable index.  We must do a complete
+      **          scan of the entire table.
+      */
+      assert( omitTable==0 );
+      assert( bRev==0 );
+      pLevel->op = OP_Next;
+      pLevel->p1 = iCur;
+      pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, OP_Rewind, iCur, brk);
+    }
+    notReady &= ~getMask(&maskSet, iCur);
+
+    /* Insert code to test every subexpression that can be completely
+    ** computed using the current set of tables.
+    */
+    for(pTerm=wc.a, j=wc.nTerm; j>0; j--, pTerm++){
+      Expr *pE;
+      testcase( pTerm->flags & TERM_VIRTUAL );
+      testcase( pTerm->flags & TERM_CODED );
+      if( pTerm->flags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+      if( (pTerm->prereqAll & notReady)!=0 ) continue;
+      pE = pTerm->pExpr;
+      assert( pE!=0 );
+      if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
+        continue;
+      }
+      sqlite3ExprIfFalse(pParse, pE, cont, SQLITE_JUMPIFNULL);
+      pTerm->flags |= TERM_CODED;
+    }
+
+    /* For a LEFT OUTER JOIN, generate code that will record the fact that
+    ** at least one row of the right table has matched the left table.  
+    */
+    if( pLevel->iLeftJoin ){
+      pLevel->top = sqlite3VdbeCurrentAddr(v);
+      sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
+      VdbeComment((v, "record LEFT JOIN hit"));
+      sqlite3ExprClearColumnCache(pParse, pLevel->iTabCur);
+      sqlite3ExprClearColumnCache(pParse, pLevel->iIdxCur);
+      for(pTerm=wc.a, j=0; j<wc.nTerm; j++, pTerm++){
+        testcase( pTerm->flags & TERM_VIRTUAL );
+        testcase( pTerm->flags & TERM_CODED );
+        if( pTerm->flags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+        if( (pTerm->prereqAll & notReady)!=0 ) continue;
+        assert( pTerm->pExpr );
+        sqlite3ExprIfFalse(pParse, pTerm->pExpr, cont, SQLITE_JUMPIFNULL);
+        pTerm->flags |= TERM_CODED;
+      }
+    }
+  }
+
+#ifdef SQLITE_TEST  /* For testing and debugging use only */
+  /* Record in the query plan information about the current table
+  ** and the index used to access it (if any).  If the table itself
+  ** is not used, its name is just '{}'.  If no index is used
+  ** the index is listed as "{}".  If the primary key is used the
+  ** index name is '*'.
+  */
+  for(i=0; i<pTabList->nSrc; i++){
+    char *z;
+    int n;
+    pLevel = &pWInfo->a[i];
+    pTabItem = &pTabList->a[pLevel->iFrom];
+    z = pTabItem->zAlias;
+    if( z==0 ) z = pTabItem->pTab->zName;
+    n = strlen(z);
+    if( n+nQPlan < sizeof(sqlite3_query_plan)-10 ){
+      if( pLevel->flags & WHERE_IDX_ONLY ){
+        memcpy(&sqlite3_query_plan[nQPlan], "{}", 2);
+        nQPlan += 2;
+      }else{
+        memcpy(&sqlite3_query_plan[nQPlan], z, n);
+        nQPlan += n;
+      }
+      sqlite3_query_plan[nQPlan++] = ' ';
+    }
+    testcase( pLevel->flags & WHERE_ROWID_EQ );
+    testcase( pLevel->flags & WHERE_ROWID_RANGE );
+    if( pLevel->flags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
+      memcpy(&sqlite3_query_plan[nQPlan], "* ", 2);
+      nQPlan += 2;
+    }else if( pLevel->pIdx==0 ){
+      memcpy(&sqlite3_query_plan[nQPlan], "{} ", 3);
+      nQPlan += 3;
+    }else{
+      n = strlen(pLevel->pIdx->zName);
+      if( n+nQPlan < sizeof(sqlite3_query_plan)-2 ){
+        memcpy(&sqlite3_query_plan[nQPlan], pLevel->pIdx->zName, n);
+        nQPlan += n;
+        sqlite3_query_plan[nQPlan++] = ' ';
+      }
+    }
+  }
+  while( nQPlan>0 && sqlite3_query_plan[nQPlan-1]==' ' ){
+    sqlite3_query_plan[--nQPlan] = 0;
+  }
+  sqlite3_query_plan[nQPlan] = 0;
+  nQPlan = 0;
+#endif /* SQLITE_TEST // Testing and debugging use only */
+
+  /* Record the continuation address in the WhereInfo structure.  Then
+  ** clean up and return.
+  */
+  pWInfo->iContinue = cont;
+  whereClauseClear(&wc);
+  return pWInfo;
+
+  /* Jump here if malloc fails */
+whereBeginNoMem:
+  whereClauseClear(&wc);
+  whereInfoFree(pWInfo);
+  return 0;
+}
+
+/*
+** Generate the end of the WHERE loop.  See comments on 
+** sqlite3WhereBegin() for additional information.
+*/
+void sqlite3WhereEnd(WhereInfo *pWInfo){
+  Parse *pParse = pWInfo->pParse;
+  Vdbe *v = pParse->pVdbe;
+  int i;
+  WhereLevel *pLevel;
+  SrcList *pTabList = pWInfo->pTabList;
+  sqlite3 *db = pParse->db;
+
+  /* Generate loop termination code.
+  */
+  sqlite3ExprClearColumnCache(pParse, -1);
+  for(i=pTabList->nSrc-1; i>=0; i--){
+    pLevel = &pWInfo->a[i];
+    sqlite3VdbeResolveLabel(v, pLevel->cont);
+    if( pLevel->op!=OP_Noop ){
+      sqlite3VdbeAddOp2(v, pLevel->op, pLevel->p1, pLevel->p2);
+    }
+    if( pLevel->nIn ){
+      struct InLoop *pIn;
+      int j;
+      sqlite3VdbeResolveLabel(v, pLevel->nxt);
+      for(j=pLevel->nIn, pIn=&pLevel->aInLoop[j-1]; j>0; j--, pIn--){
+        sqlite3VdbeJumpHere(v, pIn->topAddr+1);
+        sqlite3VdbeAddOp2(v, OP_Next, pIn->iCur, pIn->topAddr);
+        sqlite3VdbeJumpHere(v, pIn->topAddr-1);
+      }
+      sqlite3DbFree(db, pLevel->aInLoop);
+    }
+    sqlite3VdbeResolveLabel(v, pLevel->brk);
+    if( pLevel->iLeftJoin ){
+      int addr;
+      addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin);
+      sqlite3VdbeAddOp1(v, OP_NullRow, pTabList->a[i].iCursor);
+      if( pLevel->iIdxCur>=0 ){
+        sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iIdxCur);
+      }
+      sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->top);
+      sqlite3VdbeJumpHere(v, addr);
+    }
+  }
+
+  /* The "break" point is here, just past the end of the outer loop.
+  ** Set it.
+  */
+  sqlite3VdbeResolveLabel(v, pWInfo->iBreak);
+
+  /* Close all of the cursors that were opened by sqlite3WhereBegin.
+  */
+  for(i=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
+    struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
+    Table *pTab = pTabItem->pTab;
+    assert( pTab!=0 );
+    if( pTab->isEphem || pTab->pSelect ) continue;
+    if( !pWInfo->okOnePass && (pLevel->flags & WHERE_IDX_ONLY)==0 ){
+      sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
+    }
+    if( pLevel->pIdx!=0 ){
+      sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur);
+    }
+
+    /* If this scan uses an index, make code substitutions to read data
+    ** from the index in preference to the table. Sometimes, this means
+    ** the table need never be read from. This is a performance boost,
+    ** as the vdbe level waits until the table is read before actually
+    ** seeking the table cursor to the record corresponding to the current
+    ** position in the index.
+    ** 
+    ** Calls to the code generator in between sqlite3WhereBegin and
+    ** sqlite3WhereEnd will have created code that references the table
+    ** directly.  This loop scans all that code looking for opcodes
+    ** that reference the table and converts them into opcodes that
+    ** reference the index.
+    */
+    if( pLevel->pIdx ){
+      int k, j, last;
+      VdbeOp *pOp;
+      Index *pIdx = pLevel->pIdx;
+      int useIndexOnly = pLevel->flags & WHERE_IDX_ONLY;
+
+      assert( pIdx!=0 );
+      pOp = sqlite3VdbeGetOp(v, pWInfo->iTop);
+      last = sqlite3VdbeCurrentAddr(v);
+      for(k=pWInfo->iTop; k<last; k++, pOp++){
+        if( pOp->p1!=pLevel->iTabCur ) continue;
+        if( pOp->opcode==OP_Column ){
+          for(j=0; j<pIdx->nColumn; j++){
+            if( pOp->p2==pIdx->aiColumn[j] ){
+              pOp->p2 = j;
+              pOp->p1 = pLevel->iIdxCur;
+              break;
+            }
+          }
+          assert(!useIndexOnly || j<pIdx->nColumn);
+        }else if( pOp->opcode==OP_Rowid ){
+          pOp->p1 = pLevel->iIdxCur;
+          pOp->opcode = OP_IdxRowid;
+        }else if( pOp->opcode==OP_NullRow && useIndexOnly ){
+          pOp->opcode = OP_Noop;
+        }
+      }
+    }
+  }
+
+  /* Final cleanup
+  */
+  whereInfoFree(pWInfo);
+  return;
+}