void sqlite3Pragma(
  Parse *pParse, 
  Token *pId1,        /* First part of [schema.]id field */
  Token *pId2,        /* Second part of [schema.]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 */
  char *aFcntl[4];       /* Argument to SQLITE_FCNTL_PRAGMA */
  int iDb;               /* Database index for <database> */
  int rc;                      /* return value form SQLITE_FCNTL_PRAGMA */
  sqlite3 *db = pParse->db;    /* The database connection */
  Db *pDb;                     /* The specific database being pragmaed */
  Vdbe *v = sqlite3GetVdbe(pParse);  /* Prepared statement */
  const PragmaName *pPragma;   /* The pragma */

  if( v==0 ) return;
  sqlite3VdbeRunOnlyOnce(v);
  pParse->nMem = 2;

  /* Interpret the [schema.] 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);
  }

  assert( pId2 );
  zDb = pId2->n>0 ? pDb->zDbSName : 0;
  if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){
    goto pragma_out;
  }

  /* Send an SQLITE_FCNTL_PRAGMA file-control to the underlying VFS
  ** connection.  If it returns SQLITE_OK, then assume that the VFS
  ** handled the pragma and generate a no-op prepared statement.
  **
  ** IMPLEMENTATION-OF: R-12238-55120 Whenever a PRAGMA statement is parsed,
  ** an SQLITE_FCNTL_PRAGMA file control is sent to the open sqlite3_file
  ** object corresponding to the database file to which the pragma
  ** statement refers.
  **
  ** IMPLEMENTATION-OF: R-29875-31678 The argument to the SQLITE_FCNTL_PRAGMA
  ** file control is an array of pointers to strings (char**) in which the
  ** second element of the array is the name of the pragma and the third
  ** element is the argument to the pragma or NULL if the pragma has no
  ** argument.
  */
  aFcntl[0] = 0;
  aFcntl[1] = zLeft;
  aFcntl[2] = zRight;
  aFcntl[3] = 0;
  db->busyHandler.nBusy = 0;
  rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_PRAGMA, (void*)aFcntl);
  if( rc==SQLITE_OK ){
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, aFcntl[0], SQLITE_TRANSIENT);
    returnSingleText(v, aFcntl[0]);
    sqlite3_free(aFcntl[0]);
    goto pragma_out;
  }
  if( rc!=SQLITE_NOTFOUND ){
    if( aFcntl[0] ){
      sqlite3ErrorMsg(pParse, "%s", aFcntl[0]);
      sqlite3_free(aFcntl[0]);
    }
    pParse->nErr++;
    pParse->rc = rc;
    goto pragma_out;
  }

  /* Locate the pragma in the lookup table */
  pPragma = pragmaLocate(zLeft);
  if( pPragma==0 ) goto pragma_out;

  /* Make sure the database schema is loaded if the pragma requires that */
  if( (pPragma->mPragFlg & PragFlg_NeedSchema)!=0 ){
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
  }

  /* Register the result column names for pragmas that return results */
  if( (pPragma->mPragFlg & PragFlg_NoColumns)==0 
   && ((pPragma->mPragFlg & PragFlg_NoColumns1)==0 || zRight==0)
  ){
    setPragmaResultColumnNames(v, pPragma);
  }

  /* Jump to the appropriate pragma handler */
  switch( pPragma->ePragTyp ){
  
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
  /*
  **  PRAGMA [schema.]default_cache_size
  **  PRAGMA [schema.]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.
  **
  ** Older versions of SQLite would set the default cache size to a
  ** negative number to indicate synchronous=OFF.  These days, synchronous
  ** is always on by default regardless of the sign of the default cache
  ** size.  But continue to take the absolute value of the default cache
  ** size of historical compatibility.
  */
  case PragTyp_DEFAULT_CACHE_SIZE: {
    static const int iLn = VDBE_OFFSET_LINENO(2);
    static const VdbeOpList getCacheSize[] = {
      { OP_Transaction, 0, 0,        0},                         /* 0 */
      { OP_ReadCookie,  0, 1,        BTREE_DEFAULT_CACHE_SIZE},  /* 1 */
      { OP_IfPos,       1, 8,        0},
      { OP_Integer,     0, 2,        0},
      { OP_Subtract,    1, 2,        1},
      { OP_IfPos,       1, 8,        0},
      { OP_Integer,     0, 1,        0},                         /* 6 */
      { OP_Noop,        0, 0,        0},
      { OP_ResultRow,   1, 1,        0},
    };
    VdbeOp *aOp;
    sqlite3VdbeUsesBtree(v, iDb);
    if( !zRight ){
      pParse->nMem += 2;
      sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(getCacheSize));
      aOp = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize, iLn);
      if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
      aOp[0].p1 = iDb;
      aOp[1].p1 = iDb;
      aOp[6].p1 = SQLITE_DEFAULT_CACHE_SIZE;
    }else{
      int size = sqlite3AbsInt32(sqlite3Atoi(zRight));
      sqlite3BeginWriteOperation(pParse, 0, iDb);
      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, size);
      assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
      pDb->pSchema->cache_size = size;
      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
    }
    break;
  }
#endif /* !SQLITE_OMIT_PAGER_PRAGMAS && !SQLITE_OMIT_DEPRECATED */

#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  /*
  **  PRAGMA [schema.]page_size
  **  PRAGMA [schema.]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.
  */
  case PragTyp_PAGE_SIZE: {
    Btree *pBt = pDb->pBt;
    assert( pBt!=0 );
    if( !zRight ){
      int size = ALWAYS(pBt) ? sqlite3BtreeGetPageSize(pBt) : 0;
      returnSingleInt(v, 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 = sqlite3Atoi(zRight);
      if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize,-1,0) ){
        sqlite3OomFault(db);
      }
    }
    break;
  }

  /*
  **  PRAGMA [schema.]secure_delete
  **  PRAGMA [schema.]secure_delete=ON/OFF/FAST
  **
  ** The first form reports the current setting for the
  ** secure_delete flag.  The second form changes the secure_delete
  ** flag setting and reports the new value.
  */
  case PragTyp_SECURE_DELETE: {
    Btree *pBt = pDb->pBt;
    int b = -1;
    assert( pBt!=0 );
    if( zRight ){
      if( sqlite3_stricmp(zRight, "fast")==0 ){
        b = 2;
      }else{
        b = sqlite3GetBoolean(zRight, 0);
      }
    }
    if( pId2->n==0 && b>=0 ){
      int ii;
      for(ii=0; ii<db->nDb; ii++){
        sqlite3BtreeSecureDelete(db->aDb[ii].pBt, b);
      }
    }
    b = sqlite3BtreeSecureDelete(pBt, b);
    returnSingleInt(v, b);
    break;
  }

  /*
  **  PRAGMA [schema.]max_page_count
  **  PRAGMA [schema.]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.
  **
  ** The absolute value of N is used.  This is undocumented and might
  ** change.  The only purpose is to provide an easy way to test
  ** the sqlite3AbsInt32() function.
  **
  **  PRAGMA [schema.]page_count
  **
  ** Return the number of pages in the specified database.
  */
  case PragTyp_PAGE_COUNT: {
    int iReg;
    sqlite3CodeVerifySchema(pParse, iDb);
    iReg = ++pParse->nMem;
    if( sqlite3Tolower(zLeft[0])=='p' ){
      sqlite3VdbeAddOp2(v, OP_Pagecount, iDb, iReg);
    }else{
      sqlite3VdbeAddOp3(v, OP_MaxPgcnt, iDb, iReg, 
                        sqlite3AbsInt32(sqlite3Atoi(zRight)));
    }
    sqlite3VdbeAddOp2(v, OP_ResultRow, iReg, 1);
    break;
  }

  /*
  **  PRAGMA [schema.]locking_mode
  **  PRAGMA [schema.]locking_mode = (normal|exclusive)
  */
  case PragTyp_LOCKING_MODE: {
    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 = (u8)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";
    }
    returnSingleText(v, zRet);
    break;
  }

  /*
  **  PRAGMA [schema.]journal_mode
  **  PRAGMA [schema.]journal_mode =
  **                      (delete|persist|off|truncate|memory|wal|off)
  */
  case PragTyp_JOURNAL_MODE: {
    int eMode;        /* One of the PAGER_JOURNALMODE_XXX symbols */
    int ii;           /* Loop counter */

    if( zRight==0 ){
      /* If there is no "=MODE" part of the pragma, do a query for the
      ** current mode */
      eMode = PAGER_JOURNALMODE_QUERY;
    }else{
      const char *zMode;
      int n = sqlite3Strlen30(zRight);
      for(eMode=0; (zMode = sqlite3JournalModename(eMode))!=0; eMode++){
        if( sqlite3StrNICmp(zRight, zMode, n)==0 ) break;
      }
      if( !zMode ){
        /* If the "=MODE" part does not match any known journal mode,
        ** then do a query */
        eMode = PAGER_JOURNALMODE_QUERY;
      }
      if( eMode==PAGER_JOURNALMODE_OFF && (db->flags & SQLITE_Defensive)!=0 ){
        /* Do not allow journal-mode "OFF" in defensive since the database
        ** can become corrupted using ordinary SQL when the journal is off */
        eMode = PAGER_JOURNALMODE_QUERY;
      }
    }
    if( eMode==PAGER_JOURNALMODE_QUERY && pId2->n==0 ){
      /* Convert "PRAGMA journal_mode" into "PRAGMA main.journal_mode" */
      iDb = 0;
      pId2->n = 1;
    }
    for(ii=db->nDb-1; ii>=0; ii--){
      if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
        sqlite3VdbeUsesBtree(v, ii);
        sqlite3VdbeAddOp3(v, OP_JournalMode, ii, 1, eMode);
      }
    }
    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
    break;
  }

  /*
  **  PRAGMA [schema.]journal_size_limit
  **  PRAGMA [schema.]journal_size_limit=N
  **
  ** Get or set the size limit on rollback journal files.
  */
  case PragTyp_JOURNAL_SIZE_LIMIT: {
    Pager *pPager = sqlite3BtreePager(pDb->pBt);
    i64 iLimit = -2;
    if( zRight ){
      sqlite3DecOrHexToI64(zRight, &iLimit);
      if( iLimit<-1 ) iLimit = -1;
    }
    iLimit = sqlite3PagerJournalSizeLimit(pPager, iLimit);
    returnSingleInt(v, iLimit);
    break;
  }

#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

  /*
  **  PRAGMA [schema.]auto_vacuum
  **  PRAGMA [schema.]auto_vacuum=N
  **
  ** Get or set the value of the database 'auto-vacuum' parameter.
  ** The value is one of:  0 NONE 1 FULL 2 INCREMENTAL
  */
#ifndef SQLITE_OMIT_AUTOVACUUM
  case PragTyp_AUTO_VACUUM: {
    Btree *pBt = pDb->pBt;
    assert( pBt!=0 );
    if( !zRight ){
      returnSingleInt(v, sqlite3BtreeGetAutoVacuum(pBt));
    }else{
      int eAuto = getAutoVacuum(zRight);
      assert( eAuto>=0 && eAuto<=2 );
      db->nextAutovac = (u8)eAuto;
      /* 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.
      */
      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 int iLn = VDBE_OFFSET_LINENO(2);
        static const VdbeOpList setMeta6[] = {
          { OP_Transaction,    0,         1,                 0},    /* 0 */
          { OP_ReadCookie,     0,         1,         BTREE_LARGEST_ROOT_PAGE},
          { OP_If,             1,         0,                 0},    /* 2 */
          { OP_Halt,           SQLITE_OK, OE_Abort,          0},    /* 3 */
          { OP_SetCookie,      0,         BTREE_INCR_VACUUM, 0},    /* 4 */
        };
        VdbeOp *aOp;
        int iAddr = sqlite3VdbeCurrentAddr(v);
        sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setMeta6));
        aOp = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6, iLn);
        if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
        aOp[0].p1 = iDb;
        aOp[1].p1 = iDb;
        aOp[2].p2 = iAddr+4;
        aOp[4].p1 = iDb;
        aOp[4].p3 = eAuto - 1;
        sqlite3VdbeUsesBtree(v, iDb);
      }
    }
    break;
  }
#endif

  /*
  **  PRAGMA [schema.]incremental_vacuum(N)
  **
  ** Do N steps of incremental vacuuming on a database.
  */
#ifndef SQLITE_OMIT_AUTOVACUUM
  case PragTyp_INCREMENTAL_VACUUM: {
    int iLimit, addr;
    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); VdbeCoverage(v);
    sqlite3VdbeAddOp1(v, OP_ResultRow, 1);
    sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
    sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr); VdbeCoverage(v);
    sqlite3VdbeJumpHere(v, addr);
    break;
  }
#endif

#ifndef SQLITE_OMIT_PAGER_PRAGMAS
  /*
  **  PRAGMA [schema.]cache_size
  **  PRAGMA [schema.]cache_size=N
  **
  ** The first form reports the current local setting for the
  ** page cache size. The second form sets the local
  ** page cache size value.  If N is positive then that is the
  ** number of pages in the cache.  If N is negative, then the
  ** number of pages is adjusted so that the cache uses -N kibibytes
  ** of memory.
  */
  case PragTyp_CACHE_SIZE: {
    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
    if( !zRight ){
      returnSingleInt(v, pDb->pSchema->cache_size);
    }else{
      int size = sqlite3Atoi(zRight);
      pDb->pSchema->cache_size = size;
      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
    }
    break;
  }

  /*
  **  PRAGMA [schema.]cache_spill
  **  PRAGMA cache_spill=BOOLEAN
  **  PRAGMA [schema.]cache_spill=N
  **
  ** The first form reports the current local setting for the
  ** page cache spill size. The second form turns cache spill on
  ** or off.  When turnning cache spill on, the size is set to the
  ** current cache_size.  The third form sets a spill size that
  ** may be different form the cache size.
  ** If N is positive then that is the
  ** number of pages in the cache.  If N is negative, then the
  ** number of pages is adjusted so that the cache uses -N kibibytes
  ** of memory.
  **
  ** If the number of cache_spill pages is less then the number of
  ** cache_size pages, no spilling occurs until the page count exceeds
  ** the number of cache_size pages.
  **
  ** The cache_spill=BOOLEAN setting applies to all attached schemas,
  ** not just the schema specified.
  */
  case PragTyp_CACHE_SPILL: {
    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
    if( !zRight ){
      returnSingleInt(v,
         (db->flags & SQLITE_CacheSpill)==0 ? 0 : 
            sqlite3BtreeSetSpillSize(pDb->pBt,0));
    }else{
      int size = 1;
      if( sqlite3GetInt32(zRight, &size) ){
        sqlite3BtreeSetSpillSize(pDb->pBt, size);
      }
      if( sqlite3GetBoolean(zRight, size!=0) ){
        db->flags |= SQLITE_CacheSpill;
      }else{
        db->flags &= ~(u64)SQLITE_CacheSpill;
      }
      setAllPagerFlags(db);
    }
    break;
  }

  /*
  **  PRAGMA [schema.]mmap_size(N)
  **
  ** Used to set mapping size limit. The mapping size limit is
  ** used to limit the aggregate size of all memory mapped regions of the
  ** database file. If this parameter is set to zero, then memory mapping
  ** is not used at all.  If N is negative, then the default memory map
  ** limit determined by sqlite3_config(SQLITE_CONFIG_MMAP_SIZE) is set.
  ** The parameter N is measured in bytes.
  **
  ** This value is advisory.  The underlying VFS is free to memory map
  ** as little or as much as it wants.  Except, if N is set to 0 then the
  ** upper layers will never invoke the xFetch interfaces to the VFS.
  */
  case PragTyp_MMAP_SIZE: {
    sqlite3_int64 sz;
#if SQLITE_MAX_MMAP_SIZE>0
    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
    if( zRight ){
      int ii;
      sqlite3DecOrHexToI64(zRight, &sz);
      if( sz<0 ) sz = sqlite3GlobalConfig.szMmap;
      if( pId2->n==0 ) db->szMmap = sz;
      for(ii=db->nDb-1; ii>=0; ii--){
        if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
          sqlite3BtreeSetMmapLimit(db->aDb[ii].pBt, sz);
        }
      }
    }
    sz = -1;
    rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_MMAP_SIZE, &sz);
#else
    sz = 0;
    rc = SQLITE_OK;
#endif
    if( rc==SQLITE_OK ){
      returnSingleInt(v, sz);
    }else if( rc!=SQLITE_NOTFOUND ){
      pParse->nErr++;
      pParse->rc = rc;
    }
    break;
  }

  /*
  **   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
  */
  case PragTyp_TEMP_STORE: {
    if( !zRight ){
      returnSingleInt(v, db->temp_store);
    }else{
      changeTempStorage(pParse, zRight);
    }
    break;
  }

  /*
  **   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.
  **
  */
  case PragTyp_TEMP_STORE_DIRECTORY: {
    if( !zRight ){
      returnSingleText(v, sqlite3_temp_directory);
    }else{
#ifndef SQLITE_OMIT_WSD
      if( zRight[0] ){
        int res;
        rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);
        if( rc!=SQLITE_OK || 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 = sqlite3_mprintf("%s", zRight);
      }else{
        sqlite3_temp_directory = 0;
      }
#endif /* SQLITE_OMIT_WSD */
    }
    break;
  }

#if SQLITE_OS_WIN
  /*
  **   PRAGMA data_store_directory
  **   PRAGMA data_store_directory = ""|"directory_name"
  **
  ** Return or set the local value of the data_store_directory flag.  Changing
  ** the value sets a specific directory to be used for database files that
  ** were specified with a relative pathname.  Setting to a null string reverts
  ** to the default database directory, which for database files specified with
  ** a relative path will probably be based on the current directory for the
  ** process.  Database file specified with an absolute path are not impacted
  ** by this setting, regardless of its value.
  **
  */
  case PragTyp_DATA_STORE_DIRECTORY: {
    if( !zRight ){
      returnSingleText(v, sqlite3_data_directory);
    }else{
#ifndef SQLITE_OMIT_WSD
      if( zRight[0] ){
        int res;
        rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);
        if( rc!=SQLITE_OK || res==0 ){
          sqlite3ErrorMsg(pParse, "not a writable directory");
          goto pragma_out;
        }
      }
      sqlite3_free(sqlite3_data_directory);
      if( zRight[0] ){
        sqlite3_data_directory = sqlite3_mprintf("%s", zRight);
      }else{
        sqlite3_data_directory = 0;
      }
#endif /* SQLITE_OMIT_WSD */
    }
    break;
  }
#endif

#if SQLITE_ENABLE_LOCKING_STYLE
  /*
  **   PRAGMA [schema.]lock_proxy_file
  **   PRAGMA [schema.]lock_proxy_file = ":auto:"|"lock_file_path"
  **
  ** Return or set the value of the lock_proxy_file flag.  Changing
  ** the value sets a specific file to be used for database access locks.
  **
  */
  case PragTyp_LOCK_PROXY_FILE: {
    if( !zRight ){
      Pager *pPager = sqlite3BtreePager(pDb->pBt);
      char *proxy_file_path = NULL;
      sqlite3_file *pFile = sqlite3PagerFile(pPager);
      sqlite3OsFileControlHint(pFile, SQLITE_GET_LOCKPROXYFILE, 
                           &proxy_file_path);
      returnSingleText(v, proxy_file_path);
    }else{
      Pager *pPager = sqlite3BtreePager(pDb->pBt);
      sqlite3_file *pFile = sqlite3PagerFile(pPager);
      int res;
      if( zRight[0] ){
        res=sqlite3OsFileControl(pFile, SQLITE_SET_LOCKPROXYFILE, 
                                     zRight);
      } else {
        res=sqlite3OsFileControl(pFile, SQLITE_SET_LOCKPROXYFILE, 
                                     NULL);
      }
      if( res!=SQLITE_OK ){
        sqlite3ErrorMsg(pParse, "failed to set lock proxy file");
        goto pragma_out;
      }
    }
    break;
  }
#endif /* SQLITE_ENABLE_LOCKING_STYLE */      
    
  /*
  **   PRAGMA [schema.]synchronous
  **   PRAGMA [schema.]synchronous=OFF|ON|NORMAL|FULL|EXTRA
  **
  ** 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.
  */
  case PragTyp_SYNCHRONOUS: {
    if( !zRight ){
      returnSingleInt(v, pDb->safety_level-1);
    }else{
      if( !db->autoCommit ){
        sqlite3ErrorMsg(pParse, 
            "Safety level may not be changed inside a transaction");
      }else if( iDb!=1 ){
        int iLevel = (getSafetyLevel(zRight,0,1)+1) & PAGER_SYNCHRONOUS_MASK;
        if( iLevel==0 ) iLevel = 1;
        pDb->safety_level = iLevel;
        pDb->bSyncSet = 1;
        setAllPagerFlags(db);
      }
    }
    break;
  }
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

#ifndef SQLITE_OMIT_FLAG_PRAGMAS
  case PragTyp_FLAG: {
    if( zRight==0 ){
      setPragmaResultColumnNames(v, pPragma);
      returnSingleInt(v, (db->flags & pPragma->iArg)!=0 );
    }else{
      u64 mask = pPragma->iArg;    /* Mask of bits to set or clear. */
      if( db->autoCommit==0 ){
        /* Foreign key support may not be enabled or disabled while not
        ** in auto-commit mode.  */
        mask &= ~(SQLITE_ForeignKeys);
      }
#if SQLITE_USER_AUTHENTICATION
      if( db->auth.authLevel==UAUTH_User ){
        /* Do not allow non-admin users to modify the schema arbitrarily */
        mask &= ~(SQLITE_WriteSchema);
      }
#endif

      if( sqlite3GetBoolean(zRight, 0) ){
        db->flags |= mask;
      }else{
        db->flags &= ~mask;
        if( mask==SQLITE_DeferFKs ) db->nDeferredImmCons = 0;
      }

      /* 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.
      */
      sqlite3VdbeAddOp0(v, OP_Expire);
      setAllPagerFlags(db);
    }
    break;
  }
#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.
  ** pk:         Non-zero for PK fields.
  */
  case PragTyp_TABLE_INFO: if( zRight ){
    Table *pTab;
    pTab = sqlite3LocateTable(pParse, LOCATE_NOERR, zRight, zDb);
    if( pTab ){
      int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      int i, k;
      int nHidden = 0;
      Column *pCol;
      Index *pPk = sqlite3PrimaryKeyIndex(pTab);
      pParse->nMem = 7;
      sqlite3CodeVerifySchema(pParse, iTabDb);
      sqlite3ViewGetColumnNames(pParse, pTab);
      for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
        int isHidden = 0;
        if( pCol->colFlags & COLFLAG_NOINSERT ){
          if( pPragma->iArg==0 ){
            nHidden++;
            continue;
          }
          if( pCol->colFlags & COLFLAG_VIRTUAL ){
            isHidden = 2;  /* GENERATED ALWAYS AS ... VIRTUAL */
          }else if( pCol->colFlags & COLFLAG_STORED ){
            isHidden = 3;  /* GENERATED ALWAYS AS ... STORED */
          }else{ assert( pCol->colFlags & COLFLAG_HIDDEN );
            isHidden = 1;  /* HIDDEN */
          }
        }
        if( (pCol->colFlags & COLFLAG_PRIMKEY)==0 ){
          k = 0;
        }else if( pPk==0 ){
          k = 1;
        }else{
          for(k=1; k<=pTab->nCol && pPk->aiColumn[k-1]!=i; k++){}
        }
        assert( pCol->pDflt==0 || pCol->pDflt->op==TK_SPAN || isHidden>=2 );
        sqlite3VdbeMultiLoad(v, 1, pPragma->iArg ? "issisii" : "issisi",
               i-nHidden,
               pCol->zName,
               sqlite3ColumnType(pCol,""),
               pCol->notNull ? 1 : 0,
               pCol->pDflt && isHidden<2 ? pCol->pDflt->u.zToken : 0,
               k,
               isHidden);
      }
    }
  }
  break;

#ifdef SQLITE_DEBUG
  case PragTyp_STATS: {
    Index *pIdx;
    HashElem *i;
    pParse->nMem = 5;
    sqlite3CodeVerifySchema(pParse, iDb);
    for(i=sqliteHashFirst(&pDb->pSchema->tblHash); i; i=sqliteHashNext(i)){
      Table *pTab = sqliteHashData(i);
      sqlite3VdbeMultiLoad(v, 1, "ssiii",
           pTab->zName,
           0,
           pTab->szTabRow,
           pTab->nRowLogEst,
           pTab->tabFlags);
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        sqlite3VdbeMultiLoad(v, 2, "siiiX",
           pIdx->zName,
           pIdx->szIdxRow,
           pIdx->aiRowLogEst[0],
           pIdx->hasStat1);
        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 5);
      }
    }
  }
  break;
#endif

  case PragTyp_INDEX_INFO: if( zRight ){
    Index *pIdx;
    Table *pTab;
    pIdx = sqlite3FindIndex(db, zRight, zDb);
    if( pIdx==0 ){
      /* If there is no index named zRight, check to see if there is a
      ** WITHOUT ROWID table named zRight, and if there is, show the
      ** structure of the PRIMARY KEY index for that table. */
      pTab = sqlite3LocateTable(pParse, LOCATE_NOERR, zRight, zDb);
      if( pTab && !HasRowid(pTab) ){
        pIdx = sqlite3PrimaryKeyIndex(pTab);
      }
    }
    if( pIdx ){
      int iIdxDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
      int i;
      int mx;
      if( pPragma->iArg ){
        /* PRAGMA index_xinfo (newer version with more rows and columns) */
        mx = pIdx->nColumn;
        pParse->nMem = 6;
      }else{
        /* PRAGMA index_info (legacy version) */
        mx = pIdx->nKeyCol;
        pParse->nMem = 3;
      }
      pTab = pIdx->pTable;
      sqlite3CodeVerifySchema(pParse, iIdxDb);
      assert( pParse->nMem<=pPragma->nPragCName );
      for(i=0; i<mx; i++){
        i16 cnum = pIdx->aiColumn[i];
        sqlite3VdbeMultiLoad(v, 1, "iisX", i, cnum,
                             cnum<0 ? 0 : pTab->aCol[cnum].zName);
        if( pPragma->iArg ){
          sqlite3VdbeMultiLoad(v, 4, "isiX",
            pIdx->aSortOrder[i],
            pIdx->azColl[i],
            i<pIdx->nKeyCol);
        }
        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, pParse->nMem);
      }
    }
  }
  break;

  case PragTyp_INDEX_LIST: if( zRight ){
    Index *pIdx;
    Table *pTab;
    int i;
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      pParse->nMem = 5;
      sqlite3CodeVerifySchema(pParse, iTabDb);
      for(pIdx=pTab->pIndex, i=0; pIdx; pIdx=pIdx->pNext, i++){
        const char *azOrigin[] = { "c", "u", "pk" };
        sqlite3VdbeMultiLoad(v, 1, "isisi",
           i,
           pIdx->zName,
           IsUniqueIndex(pIdx),
           azOrigin[pIdx->idxType],
           pIdx->pPartIdxWhere!=0);
      }
    }
  }
  break;

  case PragTyp_DATABASE_LIST: {
    int i;
    pParse->nMem = 3;
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pBt==0 ) continue;
      assert( db->aDb[i].zDbSName!=0 );
      sqlite3VdbeMultiLoad(v, 1, "iss",
         i,
         db->aDb[i].zDbSName,
         sqlite3BtreeGetFilename(db->aDb[i].pBt));
    }
  }
  break;

  case PragTyp_COLLATION_LIST: {
    int i = 0;
    HashElem *p;
    pParse->nMem = 2;
    for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
      CollSeq *pColl = (CollSeq *)sqliteHashData(p);
      sqlite3VdbeMultiLoad(v, 1, "is", i++, pColl->zName);
    }
  }
  break;

#ifndef SQLITE_OMIT_INTROSPECTION_PRAGMAS
  case PragTyp_FUNCTION_LIST: {
    int i;
    HashElem *j;
    FuncDef *p;
    pParse->nMem = 2;
    for(i=0; i<SQLITE_FUNC_HASH_SZ; i++){
      for(p=sqlite3BuiltinFunctions.a[i]; p; p=p->u.pHash ){
        if( p->funcFlags & SQLITE_FUNC_INTERNAL ) continue;
        sqlite3VdbeMultiLoad(v, 1, "si", p->zName, 1);
      }
    }
    for(j=sqliteHashFirst(&db->aFunc); j; j=sqliteHashNext(j)){
      p = (FuncDef*)sqliteHashData(j);
      sqlite3VdbeMultiLoad(v, 1, "si", p->zName, 0);
    }
  }
  break;

#ifndef SQLITE_OMIT_VIRTUALTABLE
  case PragTyp_MODULE_LIST: {
    HashElem *j;
    pParse->nMem = 1;
    for(j=sqliteHashFirst(&db->aModule); j; j=sqliteHashNext(j)){
      Module *pMod = (Module*)sqliteHashData(j);
      sqlite3VdbeMultiLoad(v, 1, "s", pMod->zName);
    }
  }
  break;
#endif /* SQLITE_OMIT_VIRTUALTABLE */

  case PragTyp_PRAGMA_LIST: {
    int i;
    for(i=0; i<ArraySize(aPragmaName); i++){
      sqlite3VdbeMultiLoad(v, 1, "s", aPragmaName[i].zName);
    }
  }
  break;
#endif /* SQLITE_INTROSPECTION_PRAGMAS */

#endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */

#ifndef SQLITE_OMIT_FOREIGN_KEY
  case PragTyp_FOREIGN_KEY_LIST: if( zRight ){
    FKey *pFK;
    Table *pTab;
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      pFK = pTab->pFKey;
      if( pFK ){
        int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
        int i = 0; 
        pParse->nMem = 8;
        sqlite3CodeVerifySchema(pParse, iTabDb);
        while(pFK){
          int j;
          for(j=0; j<pFK->nCol; j++){
            sqlite3VdbeMultiLoad(v, 1, "iissssss",
                   i,
                   j,
                   pFK->zTo,
                   pTab->aCol[pFK->aCol[j].iFrom].zName,
                   pFK->aCol[j].zCol,
                   actionName(pFK->aAction[1]),  /* ON UPDATE */
                   actionName(pFK->aAction[0]),  /* ON DELETE */
                   "NONE");
          }
          ++i;
          pFK = pFK->pNextFrom;
        }
      }
    }
  }
  break;
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */

#ifndef SQLITE_OMIT_FOREIGN_KEY
#ifndef SQLITE_OMIT_TRIGGER
  case PragTyp_FOREIGN_KEY_CHECK: {
    FKey *pFK;             /* A foreign key constraint */
    Table *pTab;           /* Child table contain "REFERENCES" keyword */
    Table *pParent;        /* Parent table that child points to */
    Index *pIdx;           /* Index in the parent table */
    int i;                 /* Loop counter:  Foreign key number for pTab */
    int j;                 /* Loop counter:  Field of the foreign key */
    HashElem *k;           /* Loop counter:  Next table in schema */
    int x;                 /* result variable */
    int regResult;         /* 3 registers to hold a result row */
    int regKey;            /* Register to hold key for checking the FK */
    int regRow;            /* Registers to hold a row from pTab */
    int addrTop;           /* Top of a loop checking foreign keys */
    int addrOk;            /* Jump here if the key is OK */
    int *aiCols;           /* child to parent column mapping */

    regResult = pParse->nMem+1;
    pParse->nMem += 4;
    regKey = ++pParse->nMem;
    regRow = ++pParse->nMem;
    k = sqliteHashFirst(&db->aDb[iDb].pSchema->tblHash);
    while( k ){
      int iTabDb;
      if( zRight ){
        pTab = sqlite3LocateTable(pParse, 0, zRight, zDb);
        k = 0;
      }else{
        pTab = (Table*)sqliteHashData(k);
        k = sqliteHashNext(k);
      }
      if( pTab==0 || pTab->pFKey==0 ) continue;
      iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      sqlite3CodeVerifySchema(pParse, iTabDb);
      sqlite3TableLock(pParse, iTabDb, pTab->tnum, 0, pTab->zName);
      if( pTab->nCol+regRow>pParse->nMem ) pParse->nMem = pTab->nCol + regRow;
      sqlite3OpenTable(pParse, 0, iTabDb, pTab, OP_OpenRead);
      sqlite3VdbeLoadString(v, regResult, pTab->zName);
      for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){
        pParent = sqlite3FindTable(db, pFK->zTo, zDb);
        if( pParent==0 ) continue;
        pIdx = 0;
        sqlite3TableLock(pParse, iTabDb, pParent->tnum, 0, pParent->zName);
        x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, 0);
        if( x==0 ){
          if( pIdx==0 ){
            sqlite3OpenTable(pParse, i, iTabDb, pParent, OP_OpenRead);
          }else{
            sqlite3VdbeAddOp3(v, OP_OpenRead, i, pIdx->tnum, iTabDb);
            sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
          }
        }else{
          k = 0;
          break;
        }
      }
      assert( pParse->nErr>0 || pFK==0 );
      if( pFK ) break;
      if( pParse->nTab<i ) pParse->nTab = i;
      addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, 0); VdbeCoverage(v);
      for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){
        pParent = sqlite3FindTable(db, pFK->zTo, zDb);
        pIdx = 0;
        aiCols = 0;
        if( pParent ){
          x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, &aiCols);
          assert( x==0 );
        }
        addrOk = sqlite3VdbeMakeLabel(pParse);

        /* Generate code to read the child key values into registers
        ** regRow..regRow+n. If any of the child key values are NULL, this 
        ** row cannot cause an FK violation. Jump directly to addrOk in 
        ** this case. */
        for(j=0; j<pFK->nCol; j++){
          int iCol = aiCols ? aiCols[j] : pFK->aCol[j].iFrom;
          sqlite3ExprCodeGetColumnOfTable(v, pTab, 0, iCol, regRow+j);
          sqlite3VdbeAddOp2(v, OP_IsNull, regRow+j, addrOk); VdbeCoverage(v);
        }

        /* Generate code to query the parent index for a matching parent
        ** key. If a match is found, jump to addrOk. */
        if( pIdx ){
          sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, pFK->nCol, regKey,
              sqlite3IndexAffinityStr(db,pIdx), pFK->nCol);
          sqlite3VdbeAddOp4Int(v, OP_Found, i, addrOk, regKey, 0);
          VdbeCoverage(v);
        }else if( pParent ){
          int jmp = sqlite3VdbeCurrentAddr(v)+2;
          sqlite3VdbeAddOp3(v, OP_SeekRowid, i, jmp, regRow); VdbeCoverage(v);
          sqlite3VdbeGoto(v, addrOk);
          assert( pFK->nCol==1 );
        }

        /* Generate code to report an FK violation to the caller. */
        if( HasRowid(pTab) ){
          sqlite3VdbeAddOp2(v, OP_Rowid, 0, regResult+1);
        }else{
          sqlite3VdbeAddOp2(v, OP_Null, 0, regResult+1);
        }
        sqlite3VdbeMultiLoad(v, regResult+2, "siX", pFK->zTo, i-1);
        sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, 4);
        sqlite3VdbeResolveLabel(v, addrOk);
        sqlite3DbFree(db, aiCols);
      }
      sqlite3VdbeAddOp2(v, OP_Next, 0, addrTop+1); VdbeCoverage(v);
      sqlite3VdbeJumpHere(v, addrTop);
    }
  }
  break;
#endif /* !defined(SQLITE_OMIT_TRIGGER) */
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */

#ifndef SQLITE_OMIT_CASE_SENSITIVE_LIKE_PRAGMA
  /* Reinstall the LIKE and GLOB functions.  The variant of LIKE
  ** used will be case sensitive or not depending on the RHS.
  */
  case PragTyp_CASE_SENSITIVE_LIKE: {
    if( zRight ){
      sqlite3RegisterLikeFunctions(db, sqlite3GetBoolean(zRight, 0));
    }
  }
  break;
#endif /* SQLITE_OMIT_CASE_SENSITIVE_LIKE_PRAGMA */

#ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX
# define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100
#endif

#ifndef SQLITE_OMIT_INTEGRITY_CHECK
  /*    PRAGMA integrity_check
  **    PRAGMA integrity_check(N)
  **    PRAGMA quick_check
  **    PRAGMA quick_check(N)
  **
  ** Verify the integrity of the database.
  **
  ** The "quick_check" is reduced version of 
  ** integrity_check designed to detect most database corruption
  ** without the overhead of cross-checking indexes.  Quick_check
  ** is linear time wherease integrity_check is O(NlogN).
  */
  case PragTyp_INTEGRITY_CHECK: {
    int i, j, addr, mxErr;

    int isQuick = (sqlite3Tolower(zLeft[0])=='q');

    /* If the PRAGMA command was of the form "PRAGMA <db>.integrity_check",
    ** then iDb is set to the index of the database identified by <db>.
    ** In this case, the integrity of database iDb only is verified by
    ** the VDBE created below.
    **
    ** Otherwise, if the command was simply "PRAGMA integrity_check" (or
    ** "PRAGMA quick_check"), then iDb is set to 0. In this case, set iDb
    ** to -1 here, to indicate that the VDBE should verify the integrity
    ** of all attached databases.  */
    assert( iDb>=0 );
    assert( iDb==0 || pId2->z );
    if( pId2->z==0 ) iDb = -1;

    /* Initialize the VDBE program */
    pParse->nMem = 6;

    /* Set the maximum error count */
    mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
    if( zRight ){
      sqlite3GetInt32(zRight, &mxErr);
      if( mxErr<=0 ){
        mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
      }
    }
    sqlite3VdbeAddOp2(v, OP_Integer, mxErr-1, 1); /* reg[1] holds errors left */

    /* Do an integrity check on each database file */
    for(i=0; i<db->nDb; i++){
      HashElem *x;     /* For looping over tables in the schema */
      Hash *pTbls;     /* Set of all tables in the schema */
      int *aRoot;      /* Array of root page numbers of all btrees */
      int cnt = 0;     /* Number of entries in aRoot[] */
      int mxIdx = 0;   /* Maximum number of indexes for any table */

      if( OMIT_TEMPDB && i==1 ) continue;
      if( iDb>=0 && i!=iDb ) continue;

      sqlite3CodeVerifySchema(pParse, i);

      /* Do an integrity check of the B-Tree
      **
      ** Begin by finding the root pages numbers
      ** for all tables and indices in the database.
      */
      assert( sqlite3SchemaMutexHeld(db, i, 0) );
      pTbls = &db->aDb[i].pSchema->tblHash;
      for(cnt=0, x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);  /* Current table */
        Index *pIdx;                      /* An index on pTab */
        int nIdx;                         /* Number of indexes on pTab */
        if( HasRowid(pTab) ) cnt++;
        for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){ cnt++; }
        if( nIdx>mxIdx ) mxIdx = nIdx;
      }
      aRoot = sqlite3DbMallocRawNN(db, sizeof(int)*(cnt+1));
      if( aRoot==0 ) break;
      for(cnt=0, x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        if( HasRowid(pTab) ) aRoot[++cnt] = pTab->tnum;
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          aRoot[++cnt] = pIdx->tnum;
        }
      }
      aRoot[0] = cnt;

      /* Make sure sufficient number of registers have been allocated */
      pParse->nMem = MAX( pParse->nMem, 8+mxIdx );
      sqlite3ClearTempRegCache(pParse);

      /* Do the b-tree integrity checks */
      sqlite3VdbeAddOp4(v, OP_IntegrityCk, 2, cnt, 1, (char*)aRoot,P4_INTARRAY);
      sqlite3VdbeChangeP5(v, (u8)i);
      addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2); VdbeCoverage(v);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
         sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zDbSName),
         P4_DYNAMIC);
      sqlite3VdbeAddOp3(v, OP_Concat, 2, 3, 3);
      integrityCheckResultRow(v);
      sqlite3VdbeJumpHere(v, addr);

      /* Make sure all the indices are constructed correctly.
      */
      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx, *pPk;
        Index *pPrior = 0;
        int loopTop;
        int iDataCur, iIdxCur;
        int r1 = -1;

        if( pTab->tnum<1 ) continue;  /* Skip VIEWs or VIRTUAL TABLEs */
        pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
        sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenRead, 0,
                                   1, 0, &iDataCur, &iIdxCur);
        /* reg[7] counts the number of entries in the table.
        ** reg[8+i] counts the number of entries in the i-th index 
        */
        sqlite3VdbeAddOp2(v, OP_Integer, 0, 7);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          sqlite3VdbeAddOp2(v, OP_Integer, 0, 8+j); /* index entries counter */
        }
        assert( pParse->nMem>=8+j );
        assert( sqlite3NoTempsInRange(pParse,1,7+j) );
        sqlite3VdbeAddOp2(v, OP_Rewind, iDataCur, 0); VdbeCoverage(v);
        loopTop = sqlite3VdbeAddOp2(v, OP_AddImm, 7, 1);
        if( !isQuick ){
          /* Sanity check on record header decoding */
          sqlite3VdbeAddOp3(v, OP_Column, iDataCur, pTab->nNVCol-1,3);
          sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
        }
        /* Verify that all NOT NULL columns really are NOT NULL */
        for(j=0; j<pTab->nCol; j++){
          char *zErr;
          int jmp2;
          if( j==pTab->iPKey ) continue;
          if( pTab->aCol[j].notNull==0 ) continue;
          sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, j, 3);
          sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
          jmp2 = sqlite3VdbeAddOp1(v, OP_NotNull, 3); VdbeCoverage(v);
          zErr = sqlite3MPrintf(db, "NULL value in %s.%s", pTab->zName,
                              pTab->aCol[j].zName);
          sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);
          integrityCheckResultRow(v);
          sqlite3VdbeJumpHere(v, jmp2);
        }
        /* Verify CHECK constraints */
        if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
          ExprList *pCheck = sqlite3ExprListDup(db, pTab->pCheck, 0);
          if( db->mallocFailed==0 ){
            int addrCkFault = sqlite3VdbeMakeLabel(pParse);
            int addrCkOk = sqlite3VdbeMakeLabel(pParse);
            char *zErr;
            int k;
            pParse->iSelfTab = iDataCur + 1;
            for(k=pCheck->nExpr-1; k>0; k--){
              sqlite3ExprIfFalse(pParse, pCheck->a[k].pExpr, addrCkFault, 0);
            }
            sqlite3ExprIfTrue(pParse, pCheck->a[0].pExpr, addrCkOk, 
                SQLITE_JUMPIFNULL);
            sqlite3VdbeResolveLabel(v, addrCkFault);
            pParse->iSelfTab = 0;
            zErr = sqlite3MPrintf(db, "CHECK constraint failed in %s",
                pTab->zName);
            sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);
            integrityCheckResultRow(v);
            sqlite3VdbeResolveLabel(v, addrCkOk);
          }
          sqlite3ExprListDelete(db, pCheck);
        }
        if( !isQuick ){ /* Omit the remaining tests for quick_check */
          /* Validate index entries for the current row */
          for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
            int jmp2, jmp3, jmp4, jmp5;
            int ckUniq = sqlite3VdbeMakeLabel(pParse);
            if( pPk==pIdx ) continue;
            r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 0, &jmp3,
                                         pPrior, r1);
            pPrior = pIdx;
            sqlite3VdbeAddOp2(v, OP_AddImm, 8+j, 1);/* increment entry count */
            /* Verify that an index entry exists for the current table row */
            jmp2 = sqlite3VdbeAddOp4Int(v, OP_Found, iIdxCur+j, ckUniq, r1,
                                        pIdx->nColumn); VdbeCoverage(v);
            sqlite3VdbeLoadString(v, 3, "row ");
            sqlite3VdbeAddOp3(v, OP_Concat, 7, 3, 3);
            sqlite3VdbeLoadString(v, 4, " missing from index ");
            sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);
            jmp5 = sqlite3VdbeLoadString(v, 4, pIdx->zName);
            sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);
            jmp4 = integrityCheckResultRow(v);
            sqlite3VdbeJumpHere(v, jmp2);
            /* For UNIQUE indexes, verify that only one entry exists with the
            ** current key.  The entry is unique if (1) any column is NULL
            ** or (2) the next entry has a different key */
            if( IsUniqueIndex(pIdx) ){
              int uniqOk = sqlite3VdbeMakeLabel(pParse);
              int jmp6;
              int kk;
              for(kk=0; kk<pIdx->nKeyCol; kk++){
                int iCol = pIdx->aiColumn[kk];
                assert( iCol!=XN_ROWID && iCol<pTab->nCol );
                if( iCol>=0 && pTab->aCol[iCol].notNull ) continue;
                sqlite3VdbeAddOp2(v, OP_IsNull, r1+kk, uniqOk);
                VdbeCoverage(v);
              }
              jmp6 = sqlite3VdbeAddOp1(v, OP_Next, iIdxCur+j); VdbeCoverage(v);
              sqlite3VdbeGoto(v, uniqOk);
              sqlite3VdbeJumpHere(v, jmp6);
              sqlite3VdbeAddOp4Int(v, OP_IdxGT, iIdxCur+j, uniqOk, r1,
                                   pIdx->nKeyCol); VdbeCoverage(v);
              sqlite3VdbeLoadString(v, 3, "non-unique entry in index ");
              sqlite3VdbeGoto(v, jmp5);
              sqlite3VdbeResolveLabel(v, uniqOk);
            }
            sqlite3VdbeJumpHere(v, jmp4);
            sqlite3ResolvePartIdxLabel(pParse, jmp3);
          }
        }
        sqlite3VdbeAddOp2(v, OP_Next, iDataCur, loopTop); VdbeCoverage(v);
        sqlite3VdbeJumpHere(v, loopTop-1);
#ifndef SQLITE_OMIT_BTREECOUNT
        if( !isQuick ){
          sqlite3VdbeLoadString(v, 2, "wrong # of entries in index ");
          for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
            if( pPk==pIdx ) continue;
            sqlite3VdbeAddOp2(v, OP_Count, iIdxCur+j, 3);
            addr = sqlite3VdbeAddOp3(v, OP_Eq, 8+j, 0, 3); VdbeCoverage(v);
            sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
            sqlite3VdbeLoadString(v, 4, pIdx->zName);
            sqlite3VdbeAddOp3(v, OP_Concat, 4, 2, 3);
            integrityCheckResultRow(v);
            sqlite3VdbeJumpHere(v, addr);
          }
        }
#endif /* SQLITE_OMIT_BTREECOUNT */
      } 
    }
    {
      static const int iLn = VDBE_OFFSET_LINENO(2);
      static const VdbeOpList endCode[] = {
        { OP_AddImm,      1, 0,        0},    /* 0 */
        { OP_IfNotZero,   1, 4,        0},    /* 1 */
        { OP_String8,     0, 3,        0},    /* 2 */
        { OP_ResultRow,   3, 1,        0},    /* 3 */
        { OP_Halt,        0, 0,        0},    /* 4 */
        { OP_String8,     0, 3,        0},    /* 5 */
        { OP_Goto,        0, 3,        0},    /* 6 */
      };
      VdbeOp *aOp;

      aOp = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode, iLn);
      if( aOp ){
        aOp[0].p2 = 1-mxErr;
        aOp[2].p4type = P4_STATIC;
        aOp[2].p4.z = "ok";
        aOp[5].p4type = P4_STATIC;
        aOp[5].p4.z = (char*)sqlite3ErrStr(SQLITE_CORRUPT);
      }
      sqlite3VdbeChangeP3(v, 0, sqlite3VdbeCurrentAddr(v)-2);
    }
  }
  break;
#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
  */
  case PragTyp_ENCODING: {
    static const struct EncName {
      char *zName;
      u8 enc;
    } encnames[] = {
      { "UTF8",     SQLITE_UTF8        },
      { "UTF-8",    SQLITE_UTF8        },  /* Must be element [1] */
      { "UTF-16le", SQLITE_UTF16LE     },  /* Must be element [2] */
      { "UTF-16be", SQLITE_UTF16BE     },  /* Must be element [3] */
      { "UTF16le",  SQLITE_UTF16LE     },
      { "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;
      assert( encnames[SQLITE_UTF8].enc==SQLITE_UTF8 );
      assert( encnames[SQLITE_UTF16LE].enc==SQLITE_UTF16LE );
      assert( encnames[SQLITE_UTF16BE].enc==SQLITE_UTF16BE );
      returnSingleText(v, encnames[ENC(pParse->db)].zName);
    }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) ){
            SCHEMA_ENC(db) = ENC(db) =
                pEnc->enc ? pEnc->enc : SQLITE_UTF16NATIVE;
            break;
          }
        }
        if( !pEnc->zName ){
          sqlite3ErrorMsg(pParse, "unsupported encoding: %s", zRight);
        }
      }
    }
  }
  break;
#endif /* SQLITE_OMIT_UTF16 */

#ifndef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
  /*
  **   PRAGMA [schema.]schema_version
  **   PRAGMA [schema.]schema_version = <integer>
  **
  **   PRAGMA [schema.]user_version
  **   PRAGMA [schema.]user_version = <integer>
  **
  **   PRAGMA [schema.]freelist_count
  **
  **   PRAGMA [schema.]data_version
  **
  **   PRAGMA [schema.]application_id
  **   PRAGMA [schema.]application_id = <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.
  */
  case PragTyp_HEADER_VALUE: {
    int iCookie = pPragma->iArg;  /* Which cookie to read or write */
    sqlite3VdbeUsesBtree(v, iDb);
    if( zRight && (pPragma->mPragFlg & PragFlg_ReadOnly)==0 ){
      /* Write the specified cookie value */
      static const VdbeOpList setCookie[] = {
        { OP_Transaction,    0,  1,  0},    /* 0 */
        { OP_SetCookie,      0,  0,  0},    /* 1 */
      };
      VdbeOp *aOp;
      sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setCookie));
      aOp = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie, 0);
      if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
      aOp[0].p1 = iDb;
      aOp[1].p1 = iDb;
      aOp[1].p2 = iCookie;
      aOp[1].p3 = sqlite3Atoi(zRight);
    }else{
      /* Read the specified cookie value */
      static const VdbeOpList readCookie[] = {
        { OP_Transaction,     0,  0,  0},    /* 0 */
        { OP_ReadCookie,      0,  1,  0},    /* 1 */
        { OP_ResultRow,       1,  1,  0}
      };
      VdbeOp *aOp;
      sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(readCookie));
      aOp = sqlite3VdbeAddOpList(v, ArraySize(readCookie),readCookie,0);
      if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
      aOp[0].p1 = iDb;
      aOp[1].p1 = iDb;
      aOp[1].p3 = iCookie;
      sqlite3VdbeReusable(v);
    }
  }
  break;
#endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */

#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
  /*
  **   PRAGMA compile_options
  **
  ** Return the names of all compile-time options used in this build,
  ** one option per row.
  */
  case PragTyp_COMPILE_OPTIONS: {
    int i = 0;
    const char *zOpt;
    pParse->nMem = 1;
    while( (zOpt = sqlite3_compileoption_get(i++))!=0 ){
      sqlite3VdbeLoadString(v, 1, zOpt);
      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
    }
    sqlite3VdbeReusable(v);
  }
  break;
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */

#ifndef SQLITE_OMIT_WAL
  /*
  **   PRAGMA [schema.]wal_checkpoint = passive|full|restart|truncate
  **
  ** Checkpoint the database.
  */
  case PragTyp_WAL_CHECKPOINT: {
    int iBt = (pId2->z?iDb:SQLITE_MAX_ATTACHED);
    int eMode = SQLITE_CHECKPOINT_PASSIVE;
    if( zRight ){
      if( sqlite3StrICmp(zRight, "full")==0 ){
        eMode = SQLITE_CHECKPOINT_FULL;
      }else if( sqlite3StrICmp(zRight, "restart")==0 ){
        eMode = SQLITE_CHECKPOINT_RESTART;
      }else if( sqlite3StrICmp(zRight, "truncate")==0 ){
        eMode = SQLITE_CHECKPOINT_TRUNCATE;
      }
    }
    pParse->nMem = 3;
    sqlite3VdbeAddOp3(v, OP_Checkpoint, iBt, eMode, 1);
    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
  }
  break;

  /*
  **   PRAGMA wal_autocheckpoint
  **   PRAGMA wal_autocheckpoint = N
  **
  ** Configure a database connection to automatically checkpoint a database
  ** after accumulating N frames in the log. Or query for the current value
  ** of N.
  */
  case PragTyp_WAL_AUTOCHECKPOINT: {
    if( zRight ){
      sqlite3_wal_autocheckpoint(db, sqlite3Atoi(zRight));
    }
    returnSingleInt(v, 
       db->xWalCallback==sqlite3WalDefaultHook ? 
           SQLITE_PTR_TO_INT(db->pWalArg) : 0);
  }
  break;
#endif

  /*
  **  PRAGMA shrink_memory
  **
  ** IMPLEMENTATION-OF: R-23445-46109 This pragma causes the database
  ** connection on which it is invoked to free up as much memory as it
  ** can, by calling sqlite3_db_release_memory().
  */
  case PragTyp_SHRINK_MEMORY: {
    sqlite3_db_release_memory(db);
    break;
  }

  /*
  **  PRAGMA optimize
  **  PRAGMA optimize(MASK)
  **  PRAGMA schema.optimize
  **  PRAGMA schema.optimize(MASK)
  **
  ** Attempt to optimize the database.  All schemas are optimized in the first
  ** two forms, and only the specified schema is optimized in the latter two.
  **
  ** The details of optimizations performed by this pragma are expected
  ** to change and improve over time.  Applications should anticipate that
  ** this pragma will perform new optimizations in future releases.
  **
  ** The optional argument is a bitmask of optimizations to perform:
  **
  **    0x0001    Debugging mode.  Do not actually perform any optimizations
  **              but instead return one line of text for each optimization
  **              that would have been done.  Off by default.
  **
  **    0x0002    Run ANALYZE on tables that might benefit.  On by default.
  **              See below for additional information.
  **
  **    0x0004    (Not yet implemented) Record usage and performance 
  **              information from the current session in the
  **              database file so that it will be available to "optimize"
  **              pragmas run by future database connections.
  **
  **    0x0008    (Not yet implemented) Create indexes that might have
  **              been helpful to recent queries
  **
  ** The default MASK is and always shall be 0xfffe.  0xfffe means perform all
  ** of the optimizations listed above except Debug Mode, including new
  ** optimizations that have not yet been invented.  If new optimizations are
  ** ever added that should be off by default, those off-by-default 
  ** optimizations will have bitmasks of 0x10000 or larger.
  **
  ** DETERMINATION OF WHEN TO RUN ANALYZE
  **
  ** In the current implementation, a table is analyzed if only if all of
  ** the following are true:
  **
  ** (1) MASK bit 0x02 is set.
  **
  ** (2) The query planner used sqlite_stat1-style statistics for one or
  **     more indexes of the table at some point during the lifetime of
  **     the current connection.
  **
  ** (3) One or more indexes of the table are currently unanalyzed OR
  **     the number of rows in the table has increased by 25 times or more
  **     since the last time ANALYZE was run.
  **
  ** The rules for when tables are analyzed are likely to change in
  ** future releases.
  */
  case PragTyp_OPTIMIZE: {
    int iDbLast;           /* Loop termination point for the schema loop */
    int iTabCur;           /* Cursor for a table whose size needs checking */
    HashElem *k;           /* Loop over tables of a schema */
    Schema *pSchema;       /* The current schema */
    Table *pTab;           /* A table in the schema */
    Index *pIdx;           /* An index of the table */
    LogEst szThreshold;    /* Size threshold above which reanalysis is needd */
    char *zSubSql;         /* SQL statement for the OP_SqlExec opcode */
    u32 opMask;            /* Mask of operations to perform */

    if( zRight ){
      opMask = (u32)sqlite3Atoi(zRight);
      if( (opMask & 0x02)==0 ) break;
    }else{
      opMask = 0xfffe;
    }
    iTabCur = pParse->nTab++;
    for(iDbLast = zDb?iDb:db->nDb-1; iDb<=iDbLast; iDb++){
      if( iDb==1 ) continue;
      sqlite3CodeVerifySchema(pParse, iDb);
      pSchema = db->aDb[iDb].pSchema;
      for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
        pTab = (Table*)sqliteHashData(k);

        /* If table pTab has not been used in a way that would benefit from
        ** having analysis statistics during the current session, then skip it.
        ** This also has the effect of skipping virtual tables and views */
        if( (pTab->tabFlags & TF_StatsUsed)==0 ) continue;

        /* Reanalyze if the table is 25 times larger than the last analysis */
        szThreshold = pTab->nRowLogEst + 46; assert( sqlite3LogEst(25)==46 );
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          if( !pIdx->hasStat1 ){
            szThreshold = 0; /* Always analyze if any index lacks statistics */
            break;
          }
        }
        if( szThreshold ){
          sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);
          sqlite3VdbeAddOp3(v, OP_IfSmaller, iTabCur, 
                         sqlite3VdbeCurrentAddr(v)+2+(opMask&1), szThreshold);
          VdbeCoverage(v);
        }
        zSubSql = sqlite3MPrintf(db, "ANALYZE \"%w\".\"%w\"",
                                 db->aDb[iDb].zDbSName, pTab->zName);
        if( opMask & 0x01 ){
          int r1 = sqlite3GetTempReg(pParse);
          sqlite3VdbeAddOp4(v, OP_String8, 0, r1, 0, zSubSql, P4_DYNAMIC);
          sqlite3VdbeAddOp2(v, OP_ResultRow, r1, 1);
        }else{
          sqlite3VdbeAddOp4(v, OP_SqlExec, 0, 0, 0, zSubSql, P4_DYNAMIC);
        }
      }
    }
    sqlite3VdbeAddOp0(v, OP_Expire);
    break;
  }

  /*
  **   PRAGMA busy_timeout
  **   PRAGMA busy_timeout = N
  **
  ** Call sqlite3_busy_timeout(db, N).  Return the current timeout value
  ** if one is set.  If no busy handler or a different busy handler is set
  ** then 0 is returned.  Setting the busy_timeout to 0 or negative
  ** disables the timeout.
  */
  /*case PragTyp_BUSY_TIMEOUT*/ default: {
    assert( pPragma->ePragTyp==PragTyp_BUSY_TIMEOUT );
    if( zRight ){
      sqlite3_busy_timeout(db, sqlite3Atoi(zRight));
    }
    returnSingleInt(v, db->busyTimeout);
    break;
  }

  /*
  **   PRAGMA soft_heap_limit
  **   PRAGMA soft_heap_limit = N
  **
  ** IMPLEMENTATION-OF: R-26343-45930 This pragma invokes the
  ** sqlite3_soft_heap_limit64() interface with the argument N, if N is
  ** specified and is a non-negative integer.
  ** IMPLEMENTATION-OF: R-64451-07163 The soft_heap_limit pragma always
  ** returns the same integer that would be returned by the
  ** sqlite3_soft_heap_limit64(-1) C-language function.
  */
  case PragTyp_SOFT_HEAP_LIMIT: {
    sqlite3_int64 N;
    if( zRight && sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK ){
      sqlite3_soft_heap_limit64(N);
    }
    returnSingleInt(v, sqlite3_soft_heap_limit64(-1));
    break;
  }

  /*
  **   PRAGMA hard_heap_limit
  **   PRAGMA hard_heap_limit = N
  **
  ** Invoke sqlite3_hard_heap_limit64() to query or set the hard heap
  ** limit.  The hard heap limit can be activated or lowered by this
  ** pragma, but not raised or deactivated.  Only the
  ** sqlite3_hard_heap_limit64() C-language API can raise or deactivate
  ** the hard heap limit.  This allows an application to set a heap limit
  ** constraint that cannot be relaxed by an untrusted SQL script.
  */
  case PragTyp_HARD_HEAP_LIMIT: {
    sqlite3_int64 N;
    if( zRight && sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK ){
      sqlite3_int64 iPrior = sqlite3_hard_heap_limit64(-1);
      if( N>0 && (iPrior==0 || iPrior>N) ) sqlite3_hard_heap_limit64(N);
    }
    returnSingleInt(v, sqlite3_hard_heap_limit64(-1));
    break;
  }

  /*
  **   PRAGMA threads
  **   PRAGMA threads = N
  **
  ** Configure the maximum number of worker threads.  Return the new
  ** maximum, which might be less than requested.
  */
  case PragTyp_THREADS: {
    sqlite3_int64 N;
    if( zRight
     && sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK
     && N>=0
    ){
      sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, (int)(N&0x7fffffff));
    }
    returnSingleInt(v, sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, -1));
    break;
  }

#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
  /*
  ** Report the current state of file logs for all databases
  */
  case PragTyp_LOCK_STATUS: {
    static const char *const azLockName[] = {
      "unlocked", "shared", "reserved", "pending", "exclusive"
    };
    int i;
    pParse->nMem = 2;
    for(i=0; i<db->nDb; i++){
      Btree *pBt;
      const char *zState = "unknown";
      int j;
      if( db->aDb[i].zDbSName==0 ) continue;
      pBt = db->aDb[i].pBt;
      if( pBt==0 || sqlite3BtreePager(pBt)==0 ){
        zState = "closed";
      }else if( sqlite3_file_control(db, i ? db->aDb[i].zDbSName : 0, 
                                     SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
         zState = azLockName[j];
      }
      sqlite3VdbeMultiLoad(v, 1, "ss", db->aDb[i].zDbSName, zState);
    }
    break;
  }
#endif

#ifdef SQLITE_HAS_CODEC
  /* Pragma        iArg
  ** ----------   ------
  **  key           0
  **  rekey         1
  **  hexkey        2
  **  hexrekey      3
  **  textkey       4
  **  textrekey     5
  */
  case PragTyp_KEY: {
    if( zRight ){
      char zBuf[40];
      const char *zKey = zRight;
      int n;
      if( pPragma->iArg==2 || pPragma->iArg==3 ){
        u8 iByte;
        int i;
        for(i=0, iByte=0; i<sizeof(zBuf)*2 && sqlite3Isxdigit(zRight[i]); i++){
          iByte = (iByte<<4) + sqlite3HexToInt(zRight[i]);
          if( (i&1)!=0 ) zBuf[i/2] = iByte;
        }
        zKey = zBuf;
        n = i/2;
      }else{
        n = pPragma->iArg<4 ? sqlite3Strlen30(zRight) : -1;
      }
      if( (pPragma->iArg & 1)==0 ){
        rc = sqlite3_key_v2(db, zDb, zKey, n);
      }else{
        rc = sqlite3_rekey_v2(db, zDb, zKey, n);
      }
      if( rc==SQLITE_OK && n!=0 ){
        sqlite3VdbeSetNumCols(v, 1);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "ok", SQLITE_STATIC);
        returnSingleText(v, "ok");
      }
    }
    break;
  }
#endif
#if defined(SQLITE_HAS_CODEC) || defined(SQLITE_ENABLE_CEROD)
  case PragTyp_ACTIVATE_EXTENSIONS: if( zRight ){
#ifdef SQLITE_HAS_CODEC
    if( sqlite3StrNICmp(zRight, "see-", 4)==0 ){
      sqlite3_activate_see(&zRight[4]);
    }
#endif
#ifdef SQLITE_ENABLE_CEROD
    if( sqlite3StrNICmp(zRight, "cerod-", 6)==0 ){
      sqlite3_activate_cerod(&zRight[6]);
    }
#endif
  }
  break;
#endif

  } /* End of the PRAGMA switch */

  /* The following block is a no-op unless SQLITE_DEBUG is defined. Its only
  ** purpose is to execute assert() statements to verify that if the
  ** PragFlg_NoColumns1 flag is set and the caller specified an argument
  ** to the PRAGMA, the implementation has not added any OP_ResultRow 
  ** instructions to the VM.  */
  if( (pPragma->mPragFlg & PragFlg_NoColumns1) && zRight ){
    sqlite3VdbeVerifyNoResultRow(v);
  }

pragma_out:
  sqlite3DbFree(db, zLeft);
  sqlite3DbFree(db, zRight);
}