예제 #1
0
파일: vacuum.c 프로젝트: WeyrSDev/gamecode3
/*
** 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 */
  const char *zFilename;  /* full pathname of the database file */
  int nFilename;          /* number of characters  in zFilename[] */
  char *zTemp = 0;        /* a temporary file in same directory as zFilename */
  Btree *pMain;           /* The database being vacuumed */
  Btree *pTemp;
  char *zSql = 0;
  int saved_flags;       /* Saved value of the db->flags */
  Db *pDb = 0;           /* Database to detach at end of vacuum */

  /* Save the current value of the write-schema flag before setting it. */
  saved_flags = db->flags;
  db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;

  if( !db->autoCommit ){
    sqlite3SetString(pzErrMsg, "cannot VACUUM from within a transaction", 
       (char*)0);
    rc = SQLITE_ERROR;
    goto end_of_vacuum;
  }

  /* Get the full pathname of the database file and create a
  ** temporary filename in the same directory as the original file.
  */
  pMain = db->aDb[0].pBt;
  zFilename = sqlite3BtreeGetFilename(pMain);
  assert( zFilename );
  if( zFilename[0]=='\0' ){
    /* The in-memory database. Do nothing. Return directly to avoid causing
    ** an error trying to DETACH the vacuum_db (which never got attached)
    ** in the exit-handler.
    */
    return SQLITE_OK;
  }
  nFilename = strlen(zFilename);
  zTemp = sqliteMalloc( nFilename+100 );
  if( zTemp==0 ){
    rc = SQLITE_NOMEM;
    goto end_of_vacuum;
  }
  strcpy(zTemp, zFilename);

  /* The randomName() procedure in the following loop uses an excellent
  ** source of randomness to generate a name from a space of 1.3e+31 
  ** possibilities.  So unless the directory already contains on the order
  ** of 1.3e+31 files, the probability that the following loop will
  ** run more than once or twice is vanishingly small.  We are certain
  ** enough that this loop will always terminate (and terminate quickly)
  ** that we don't even bother to set a maximum loop count.
  */
  do {
    zTemp[nFilename] = '-';
    randomName((unsigned char*)&zTemp[nFilename+1]);
  } while( sqlite3OsFileExists(zTemp) );

  /* 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.
  */
  zSql = sqlite3MPrintf("ATTACH '%q' AS vacuum_db;", zTemp);
  if( !zSql ){
    rc = SQLITE_NOMEM;
    goto end_of_vacuum;
  }
  rc = execSql(db, zSql);
  sqliteFree(zSql);
  zSql = 0;
  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;
  sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain),
     sqlite3BtreeGetReserve(pMain));
  assert( sqlite3BtreeGetPageSize(pTemp)==sqlite3BtreeGetPageSize(pMain) );
  rc = execSql(db, "PRAGMA vacuum_db.synchronous=OFF");
  if( rc!=SQLITE_OK ){
    goto end_of_vacuum;
  }

#ifndef SQLITE_OMIT_AUTOVACUUM
  sqlite3BtreeSetAutoVacuum(pTemp, 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,14,100000000) "
      "  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,14,100000000)"
      "  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,21,100000000) "
      "  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);
  }

end_of_vacuum:
  /* Restore the original value of db->flags */
  db->flags = saved_flags;

  /* 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 ){
    sqlite3MallocDisallow();
    sqlite3BtreeClose(pDb->pBt);
    sqlite3MallocAllow();
    pDb->pBt = 0;
    pDb->pSchema = 0;
  }

  if( zTemp ){
    sqlite3OsDelete(zTemp);
    sqliteFree(zTemp);
  }
  sqliteFree( zSql );
  sqlite3ResetInternalSchema(db, 0);

  return rc;
}
예제 #2
0
파일: pragma.c 프로젝트: tmarques/waheela
/*
** 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 = sqlite3GetVdbe(pParse);
  if( v==0 ) return;

  /* 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];

  zLeft = sqlite3NameFromToken(pId);
  if( !zLeft ) return;
  if( minusFlag ){
    zRight = sqlite3MPrintf("-%T", pValue);
  }else{
    zRight = sqlite3NameFromToken(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, 2,        0},  /* 0 */
      { OP_AbsValue,    0, 0,        0},
      { OP_Dup,         0, 0,        0},
      { OP_Integer,     0, 0,        0},
      { OP_Ne,          0, 6,        0},
      { OP_Integer,     0, 0,        0},  /* 5 */
      { OP_Callback,    1, 0,        0},
    };
    int addr;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    if( !zRight ){
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cache_size", P3_STATIC);
      addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP1(v, addr+5, MAX_PAGES);
    }else{
      int size = atoi(zRight);
      if( size<0 ) size = -size;
      sqlite3BeginWriteOperation(pParse, 0, iDb);
      sqlite3VdbeAddOp(v, OP_Integer, size, 0);
      sqlite3VdbeAddOp(v, OP_ReadCookie, iDb, 2);
      addr = sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
      sqlite3VdbeAddOp(v, OP_Ge, 0, addr+3);
      sqlite3VdbeAddOp(v, OP_Negative, 0, 0);
      sqlite3VdbeAddOp(v, OP_SetCookie, iDb, 2);
      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{
      sqlite3BtreeSetPageSize(pBt, atoi(zRight), -1);
    }
  }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( !zRight ){
      int auto_vacuum = 
          pBt ? sqlite3BtreeGetAutoVacuum(pBt) : SQLITE_DEFAULT_AUTOVACUUM;
      returnSingleInt(pParse, "auto_vacuum", auto_vacuum);
    }else{
      sqlite3BtreeSetAutoVacuum(pBt, getBoolean(zRight));
    }
  }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", P3_STATIC);
        sqlite3VdbeOp3(v, OP_String8, 0, 0, sqlite3_temp_directory, 0);
        sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
      }
    }else{
      if( zRight[0] && !sqlite3OsIsDirWritable(zRight) ){
        sqlite3ErrorMsg(pParse, "not a writable directory");
        goto pragma_out;
      }
      if( TEMP_STORE==0
       || (TEMP_STORE==1 && db->temp_store<=1)
       || (TEMP_STORE==2 && db->temp_store==1)
      ){
        invalidateTempStorage(pParse);
      }
      sqliteFree(sqlite3_temp_directory);
      if( zRight[0] ){
        sqlite3_temp_directory = zRight;
        zRight = 0;
      }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;
      Column *pCol;
      sqlite3VdbeSetNumCols(v, 6);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cid", P3_STATIC);
      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P3_STATIC);
      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "type", P3_STATIC);
      sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "notnull", P3_STATIC);
      sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "dflt_value", P3_STATIC);
      sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "pk", P3_STATIC);
      sqlite3ViewGetColumnNames(pParse, pTab);
      for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
        sqlite3VdbeAddOp(v, OP_Integer, i, 0);
        sqlite3VdbeOp3(v, OP_String8, 0, 0, pCol->zName, 0);
        sqlite3VdbeOp3(v, OP_String8, 0, 0,
           pCol->zType ? pCol->zType : "numeric", 0);
        sqlite3VdbeAddOp(v, OP_Integer, pCol->notNull, 0);
        sqlite3ExprCode(pParse, pCol->pDflt);
        sqlite3VdbeAddOp(v, OP_Integer, pCol->isPrimKey, 0);
        sqlite3VdbeAddOp(v, OP_Callback, 6, 0);
      }
    }
  }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);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", P3_STATIC);
      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", P3_STATIC);
      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", P3_STATIC);
      for(i=0; i<pIdx->nColumn; i++){
        int cnum = pIdx->aiColumn[i];
        sqlite3VdbeAddOp(v, OP_Integer, i, 0);
        sqlite3VdbeAddOp(v, OP_Integer, cnum, 0);
        assert( pTab->nCol>cnum );
        sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->aCol[cnum].zName, 0);
        sqlite3VdbeAddOp(v, OP_Callback, 3, 0);
      }
    }
  }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);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P3_STATIC);
        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P3_STATIC);
        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", P3_STATIC);
        while(pIdx){
          sqlite3VdbeAddOp(v, OP_Integer, i, 0);
          sqlite3VdbeOp3(v, OP_String8, 0, 0, pIdx->zName, 0);
          sqlite3VdbeAddOp(v, OP_Integer, pIdx->onError!=OE_None, 0);
          sqlite3VdbeAddOp(v, OP_Callback, 3, 0);
          ++i;
          pIdx = pIdx->pNext;
        }
      }
    }
  }else

  if( sqlite3StrICmp(zLeft, "database_list")==0 ){
    int i;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeSetNumCols(v, 3);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P3_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P3_STATIC);
    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "file", P3_STATIC);
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pBt==0 ) continue;
      assert( db->aDb[i].zName!=0 );
      sqlite3VdbeAddOp(v, OP_Integer, i, 0);
      sqlite3VdbeOp3(v, OP_String8, 0, 0, db->aDb[i].zName, 0);
      sqlite3VdbeOp3(v, OP_String8, 0, 0,
           sqlite3BtreeGetFilename(db->aDb[i].pBt), 0);
      sqlite3VdbeAddOp(v, OP_Callback, 3, 0);
    }
  }else

  if( sqlite3StrICmp(zLeft, "collation_list")==0 ){
    int i = 0;
    HashElem *p;
    sqlite3VdbeSetNumCols(v, 2);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P3_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P3_STATIC);
    for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
      CollSeq *pColl = (CollSeq *)sqliteHashData(p);
      sqlite3VdbeAddOp(v, OP_Integer, i++, 0);
      sqlite3VdbeOp3(v, OP_String8, 0, 0, pColl->zName, 0);
      sqlite3VdbeAddOp(v, OP_Callback, 2, 0);
    }
  }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);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "id", P3_STATIC);
        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "seq", P3_STATIC);
        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "table", P3_STATIC);
        sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "from", P3_STATIC);
        sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "to", P3_STATIC);
        while(pFK){
          int j;
          for(j=0; j<pFK->nCol; j++){
            char *zCol = pFK->aCol[j].zCol;
            sqlite3VdbeAddOp(v, OP_Integer, i, 0);
            sqlite3VdbeAddOp(v, OP_Integer, j, 0);
            sqlite3VdbeOp3(v, OP_String8, 0, 0, pFK->zTo, 0);
            sqlite3VdbeOp3(v, OP_String8, 0, 0,
                             pTab->aCol[pFK->aCol[j].iFrom].zName, 0);
            sqlite3VdbeOp3(v, zCol ? OP_String8 : OP_Null, 0, 0, zCol, 0);
            sqlite3VdbeAddOp(v, OP_Callback, 5, 0);
          }
          ++i;
          pFK = pFK->pNextFrom;
        }
      }
    }
  }else
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */

#ifndef NDEBUG
  if( sqlite3StrICmp(zLeft, "parser_trace")==0 ){
    extern void sqlite3ParserTrace(FILE*, char *);
    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_OMIT_INTEGRITY_CHECK
  if( sqlite3StrICmp(zLeft, "integrity_check")==0 ){
    int i, j, addr;

    /* 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_MemLoad,     0, 0,        0},
      { OP_Integer,     0, 0,        0},
      { OP_Ne,          0, 0,        0},    /* 2 */
      { OP_String8,     0, 0,        "ok"},
      { OP_Callback,    1, 0,        0},
    };

    /* Initialize the VDBE program */
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", P3_STATIC);
    sqlite3VdbeAddOp(v, OP_MemInt, 0, 0);  /* Initialize error count to 0 */

    /* 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);

      /* Do an integrity check of the B-Tree
      */
      pTbls = &db->aDb[i].pSchema->tblHash;
      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        sqlite3VdbeAddOp(v, OP_Integer, pTab->tnum, 0);
        cnt++;
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          sqlite3VdbeAddOp(v, OP_Integer, pIdx->tnum, 0);
          cnt++;
        }
      }
      assert( cnt>0 );
      sqlite3VdbeAddOp(v, OP_IntegrityCk, cnt, i);
      sqlite3VdbeAddOp(v, OP_Dup, 0, 1);
      addr = sqlite3VdbeOp3(v, OP_String8, 0, 0, "ok", P3_STATIC);
      sqlite3VdbeAddOp(v, OP_Eq, 0, addr+7);
      sqlite3VdbeOp3(v, OP_String8, 0, 0,
         sqlite3MPrintf("*** in database %s ***\n", db->aDb[i].zName),
         P3_DYNAMIC);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      sqlite3VdbeAddOp(v, OP_Concat, 0, 1);
      sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
      sqlite3VdbeAddOp(v, OP_MemIncr, 1, 0);

      /* Make sure all the indices are constructed correctly.
      */
      sqlite3CodeVerifySchema(pParse, i);
      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        int loopTop;

        if( pTab->pIndex==0 ) continue;
        sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
        sqlite3VdbeAddOp(v, OP_MemInt, 0, 1);
        loopTop = sqlite3VdbeAddOp(v, OP_Rewind, 1, 0);
        sqlite3VdbeAddOp(v, OP_MemIncr, 1, 1);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          int jmp2;
          static const VdbeOpList idxErr[] = {
            { OP_MemIncr,     1,  0,  0},
            { OP_String8,     0,  0,  "rowid "},
            { OP_Rowid,       1,  0,  0},
            { OP_String8,     0,  0,  " missing from index "},
            { OP_String8,     0,  0,  0},    /* 4 */
            { OP_Concat,      2,  0,  0},
            { OP_Callback,    1,  0,  0},
          };
          sqlite3GenerateIndexKey(v, pIdx, 1);
          jmp2 = sqlite3VdbeAddOp(v, OP_Found, j+2, 0);
          addr = sqlite3VdbeAddOpList(v, ArraySize(idxErr), idxErr);
          sqlite3VdbeChangeP3(v, addr+4, pIdx->zName, P3_STATIC);
          sqlite3VdbeJumpHere(v, jmp2);
        }
        sqlite3VdbeAddOp(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_MemInt,       0,  2,  0},
             { OP_Rewind,       0,  0,  0},  /* 1 */
             { OP_MemIncr,      1,  2,  0},
             { OP_Next,         0,  0,  0},  /* 3 */
             { OP_MemLoad,      1,  0,  0},
             { OP_MemLoad,      2,  0,  0},
             { OP_Eq,           0,  0,  0},  /* 6 */
             { OP_MemIncr,      1,  0,  0},
             { OP_String8,      0,  0,  "wrong # of entries in index "},
             { OP_String8,      0,  0,  0},  /* 9 */
             { OP_Concat,       0,  0,  0},
             { OP_Callback,     1,  0,  0},
          };
          if( pIdx->tnum==0 ) continue;
          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+6);
          sqlite3VdbeChangeP3(v, addr+9, pIdx->zName, P3_STATIC);
        }
      } 
    }
    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
    sqlite3VdbeJumpHere(v, addr+2);
  }else
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_UTF16
  /*
  **   PRAGMA encoding
  **   PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be"
  **
  ** In it's 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 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 /* Filled in at run-time */ },
      { "UTF16",    0 /* Filled in at run-time */ },
      { 0, 0 }
    };
    struct EncName *pEnc;
    encnames[6].enc = encnames[7].enc = SQLITE_UTF16NATIVE;
    if( !zRight ){    /* "PRAGMA encoding" */
      if( sqlite3ReadSchema(pParse) ) goto pragma_out;
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "encoding", P3_STATIC);
      sqlite3VdbeAddOp(v, OP_String8, 0, 0);
      for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
        if( pEnc->enc==ENC(pParse->db) ){
          sqlite3VdbeChangeP3(v, -1, pEnc->zName, P3_STATIC);
          break;
        }
      }
      sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
    }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;
            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 ){

    int iCookie;   /* Cookie index. 0 for schema-cookie, 6 for user-cookie. */
    if( zLeft[0]=='s' || zLeft[0]=='S' ){
      iCookie = 0;
    }else{
      iCookie = 5;
    }

    if( zRight ){
      /* Write the specified cookie value */
      static const VdbeOpList setCookie[] = {
        { OP_Transaction,    0,  1,  0},    /* 0 */
        { OP_Integer,        0,  0,  0},    /* 1 */
        { OP_SetCookie,      0,  0,  0},    /* 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,  0,  0},    /* 0 */
        { OP_Callback,        1,  0,  0}
      };
      int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP2(v, addr, iCookie);
      sqlite3VdbeSetNumCols(v, 1);
    }
  }
#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);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", P3_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "status", P3_STATIC);
    for(i=0; i<db->nDb; i++){
      Btree *pBt;
      Pager *pPager;
      if( db->aDb[i].zName==0 ) continue;
      sqlite3VdbeOp3(v, OP_String8, 0, 0, db->aDb[i].zName, P3_STATIC);
      pBt = db->aDb[i].pBt;
      if( pBt==0 || (pPager = sqlite3BtreePager(pBt))==0 ){
        sqlite3VdbeOp3(v, OP_String8, 0, 0, "closed", P3_STATIC);
      }else{
        int j = sqlite3pager_lockstate(pPager);
        sqlite3VdbeOp3(v, OP_String8, 0, 0, 
            (j>=0 && j<=4) ? azLockName[j] : "unknown", P3_STATIC);
      }
      sqlite3VdbeAddOp(v, OP_Callback, 2, 0);
    }
  }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( 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.
    */
    sqlite3VdbeAddOp(v, OP_Expire, 1, 0);

    /*
    ** Reset the safety level, in case the fullfsync flag or synchronous
    ** setting changed.
    */
    if( db->autoCommit ){
      sqlite3BtreeSetSafetyLevel(pDb->pBt, pDb->safety_level,
                 (db->flags&SQLITE_FullFSync)!=0);
    }
  }
pragma_out:
  sqliteFree(zLeft);
  sqliteFree(zRight);
}
예제 #3
0
/*
** 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 */
  Pager *pMainPager;      /* Pager for 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 isMemDb;            /* True is vacuuming a :memory: database */
  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;
  pMainPager = sqlite3BtreePager(pMain);
  isMemDb = sqlite3PagerFile(pMainPager)->pMethods==0;

  /* 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)
   || (!isMemDb && 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<ArraySize(aCopy); 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;
#ifndef SQLITE_OMIT_AUTOVACUUM
    sqlite3BtreeSetAutoVacuum(pMain, sqlite3BtreeGetAutoVacuum(pTemp));
#endif
    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;
}
예제 #4
0
/* CHANGE 1 of 3: Add function parameter nRes */
SQLITE_PRIVATE int sqlite3RunVacuumForRekey(char **pzErrMsg, sqlite3 *db, int iDb, int nRes){
  int rc = SQLITE_OK;     /* Return code from service routines */
  Btree *pMain;           /* The database being vacuumed */
  Btree *pTemp;           /* The temporary database we vacuum into */
  u16 saved_mDbFlags;     /* Saved value of db->mDbFlags */
  u32 saved_flags;        /* Saved value of db->flags */
  int saved_nChange;      /* Saved value of db->nChange */
  int saved_nTotalChange; /* Saved value of db->nTotalChange */
  u8 saved_mTrace;        /* Saved trace settings */
  Db *pDb = 0;            /* Database to detach at end of vacuum */
  int isMemDb;            /* True if vacuuming a :memory: database */
  /* CHANGE 2 of 3: Do not define local variable nRes */
  /*int nRes;*/               /* Bytes of reserved space at the end of each page */
  int nDb;                /* Number of attached databases */
  const char *zDbMain;    /* Schema name of database to vacuum */

  if (!db->autoCommit) {
    sqlite3SetString(pzErrMsg, db, "cannot VACUUM from within a transaction");
    return SQLITE_ERROR;
  }
  if (db->nVdbeActive>1) {
    sqlite3SetString(pzErrMsg, db, "cannot VACUUM - SQL statements in progress");
    return SQLITE_ERROR;
  }

  /* Save the current value of the database flags so that it can be
  ** restored before returning. Then set the writable-schema flag, and
  ** disable CHECK and foreign key constraints.  */
  saved_flags = db->flags;
  saved_mDbFlags = db->mDbFlags;
  saved_nChange = db->nChange;
  saved_nTotalChange = db->nTotalChange;
  saved_mTrace = db->mTrace;
  db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;
  db->mDbFlags |= DBFLAG_PreferBuiltin | DBFLAG_Vacuum;
  db->flags &= ~(SQLITE_ForeignKeys | SQLITE_ReverseOrder | SQLITE_CountRows);
  db->mTrace = 0;

  zDbMain = db->aDb[iDb].zDbSName;
  pMain = db->aDb[iDb].pBt;
  isMemDb = sqlite3PagerIsMemdb(sqlite3BtreePager(pMain));

  /* 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.
  */
  nDb = db->nDb;
  rc = execSql(db, pzErrMsg, "ATTACH''AS vacuum_db");
  if (rc != SQLITE_OK) goto end_of_vacuum;
  assert((db->nDb - 1) == nDb);
  pDb = &db->aDb[nDb];
  assert(strcmp(pDb->zDbSName, "vacuum_db") == 0);
  pTemp = pDb->pBt;

  /* The call to execSql() to attach the temp database has left the file
  ** locked (as there was more than one active statement when the transaction
  ** to read the schema was concluded. Unlock it here so that this doesn't
  ** cause problems for the call to BtreeSetPageSize() below.  */
  sqlite3BtreeCommit(pTemp);

  /* CHANGE 3 of 3: Do not call sqlite3BtreeGetOptimalReserve */
  /* nRes = sqlite3BtreeGetOptimalReserve(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, iDb, (void**)&zKey, &nKey);
    if (nKey) db->nextPagesize = 0;
  }
#endif

  sqlite3BtreeSetCacheSize(pTemp, db->aDb[iDb].pSchema->cache_size);
  sqlite3BtreeSetSpillSize(pTemp, sqlite3BtreeSetSpillSize(pMain, 0));
  sqlite3BtreeSetPagerFlags(pTemp, PAGER_SYNCHRONOUS_OFF | PAGER_CACHESPILL);

  /* Begin a transaction and take an exclusive lock on the main database
  ** file. This is done before the sqlite3BtreeGetPageSize(pMain) call below,
  ** to ensure that we do not try to change the page-size on a WAL database.
  */
  rc = execSql(db, pzErrMsg, "BEGIN");
  if (rc != SQLITE_OK) goto end_of_vacuum;
  rc = sqlite3BtreeBeginTrans(pMain, 2);
  if (rc != SQLITE_OK) goto end_of_vacuum;

  /* Do not attempt to change the page size for a WAL database */
  if (sqlite3PagerGetJournalMode(sqlite3BtreePager(pMain))
    == PAGER_JOURNALMODE_WAL) {
    db->nextPagesize = 0;
  }

  if (sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain), nRes, 0)
    || (!isMemDb && sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes, 0))
    || NEVER(db->mallocFailed)
    ) {
    rc = SQLITE_NOMEM_BKPT;
    goto end_of_vacuum;
  }

#ifndef SQLITE_OMIT_AUTOVACUUM
  sqlite3BtreeSetAutoVacuum(pTemp, db->nextAutovac >= 0 ? db->nextAutovac :
    sqlite3BtreeGetAutoVacuum(pMain));
#endif

  /* Query the schema of the main database. Create a mirror schema
  ** in the temporary database.
  */
  db->init.iDb = nDb; /* force new CREATE statements into vacuum_db */
  rc = execSqlF(db, pzErrMsg,
    "SELECT sql FROM \"%w\".sqlite_master"
    " WHERE type='table'AND name<>'sqlite_sequence'"
    " AND coalesce(rootpage,1)>0",
    zDbMain
  );
  if (rc != SQLITE_OK) goto end_of_vacuum;
  rc = execSqlF(db, pzErrMsg,
    "SELECT sql FROM \"%w\".sqlite_master"
    " WHERE type='index'",
    zDbMain
  );
  if (rc != SQLITE_OK) goto end_of_vacuum;
  db->init.iDb = 0;

  /* Loop through the tables in the main database. For each, do
  ** an "INSERT INTO vacuum_db.xxx SELECT * FROM main.xxx;" to copy
  ** the contents to the temporary database.
  */
  rc = execSqlF(db, pzErrMsg,
    "SELECT'INSERT INTO vacuum_db.'||quote(name)"
    "||' SELECT*FROM\"%w\".'||quote(name)"
    "FROM vacuum_db.sqlite_master "
    "WHERE type='table'AND coalesce(rootpage,1)>0",
    zDbMain
  );
  assert((db->mDbFlags & DBFLAG_Vacuum) != 0);
  db->mDbFlags &= ~DBFLAG_Vacuum;
  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 = execSqlF(db, pzErrMsg,
    "INSERT INTO vacuum_db.sqlite_master"
    " SELECT*FROM \"%w\".sqlite_master"
    " WHERE type IN('view','trigger')"
    " OR(type='table'AND rootpage=0)",
    zDbMain
  );
  if (rc) goto end_of_vacuum;

  /* At this point, there is a write transaction open on both the
  ** vacuum database and the main database. Assuming no error occurs,
  ** both transactions are closed by this block - the main database
  ** transaction by sqlite3BtreeCopyFile() and the other by an explicit
  ** call to sqlite3BtreeCommit().
  */
  {
    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[] = {
      BTREE_SCHEMA_VERSION,     1,  /* Add one to the old schema cookie */
      BTREE_DEFAULT_CACHE_SIZE, 0,  /* Preserve the default page cache size */
      BTREE_TEXT_ENCODING,      0,  /* Preserve the text encoding */
      BTREE_USER_VERSION,       0,  /* Preserve the user version */
      BTREE_APPLICATION_ID,     0,  /* Preserve the application id */
    };

    assert(1 == sqlite3BtreeIsInTrans(pTemp));
    assert(1 == sqlite3BtreeIsInTrans(pMain));

    /* Copy Btree meta values */
    for (i = 0; i<ArraySize(aCopy); i += 2) {
      /* GetMeta() and UpdateMeta() cannot fail in this context because
      ** we already have page 1 loaded into cache and marked dirty. */
      sqlite3BtreeGetMeta(pMain, aCopy[i], &meta);
      rc = sqlite3BtreeUpdateMeta(pTemp, aCopy[i], meta + aCopy[i + 1]);
      if (NEVER(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;
#ifndef SQLITE_OMIT_AUTOVACUUM
    sqlite3BtreeSetAutoVacuum(pMain, sqlite3BtreeGetAutoVacuum(pTemp));
#endif
  }

  assert(rc == SQLITE_OK);
  rc = sqlite3BtreeSetPageSize(pMain, sqlite3BtreeGetPageSize(pTemp), nRes, 1);

end_of_vacuum:
  /* Restore the original value of db->flags */
  db->init.iDb = 0;
  db->mDbFlags = saved_mDbFlags;
  db->flags = saved_flags;
  db->nChange = saved_nChange;
  db->nTotalChange = saved_nTotalChange;
  db->mTrace = saved_mTrace;
  sqlite3BtreeSetPageSize(pMain, -1, -1, 1);

  /* 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;
  }

  /* This both clears the schemas and reduces the size of the db->aDb[]
  ** array. */
  sqlite3ResetAllSchemasOfConnection(db);

  return rc;
}
예제 #5
0
파일: vacuum.c 프로젝트: Mayalinux/db
/*
** A write transaction must be opened before calling this function.
** It performs a single unit of work towards an incremental vacuum.
** Specifically, in the Berkeley DB storage manager, it attempts to compact
** one table.
**
** If the incremental vacuum is finished after this function has run,
** SQLITE_DONE is returned. If it is not finished, but no error occurred,
** SQLITE_OK is returned. Otherwise an SQLite error code.
**
** The caller can get and accumulate the number of truncated pages truncated
** with input parameter truncatedPages. Also, btreeIncrVacuum would skip
** the vacuum if enough pages has been truncated for optimization.
*/
int btreeIncrVacuum(Btree *p, u_int32_t *truncatedPages)
{
	BtShared *pBt;
	CACHED_DB *cached_db;
	DB *dbp;
	DBT key, data;
	char *fileName, *tableName, tableNameBuf[DBNAME_SIZE];
	void *app;
	int iTable, rc, ret, t_ret;
	u_int32_t was_create;
	DB_COMPACT compact_data;
	DBT *pStart, end;	/* start/end of db_compact() */
	struct VacuumInfo *pInfo;
	int vacuumMode;

	assert(p->pBt->dbStorage == DB_STORE_NAMED);

	if (!p->connected && (rc = btreeOpenEnvironment(p, 1)) != SQLITE_OK)
		return rc;

	pBt = p->pBt;
	rc = SQLITE_OK;
	cached_db = NULL;
	dbp = NULL;
	memset(&end, 0, sizeof(end));
#ifndef BDBSQL_OMIT_LEAKCHECK
	/* Let BDB use the user-specified malloc function (btreeMalloc) */
	end.flags |= DB_DBT_MALLOC;
#endif

	/*
	 * Turn off DB_CREATE: we don't want to create any tables that don't
	 * already exist.
	 */
	was_create = (pBt->db_oflags & DB_CREATE);
	pBt->db_oflags &= ~DB_CREATE;

	memset(&key, 0, sizeof(key));
	key.data = tableNameBuf;
	key.ulen = sizeof(tableNameBuf);
	key.flags = DB_DBT_USERMEM;
	memset(&data, 0, sizeof(data));
	data.flags = DB_DBT_PARTIAL | DB_DBT_USERMEM;

	UPDATE_DURING_BACKUP(p);

	if (p->compact_cursor == NULL) {
		if ((ret = pTablesDb->cursor(pTablesDb, pReadTxn,
		    &p->compact_cursor, 0)) != 0)
			goto err;
	}
	if ((ret = p->compact_cursor->get(p->compact_cursor,
	    &key, &data, DB_NEXT)) == DB_NOTFOUND) {
		(void)p->compact_cursor->close(p->compact_cursor);
		p->compact_cursor = NULL;
		pBt->db_oflags |= was_create;
		return SQLITE_DONE;
	} else if (ret != 0)
		goto err;

	tableNameBuf[key.size] = '\0';
	if (strncmp(tableNameBuf, "table", 5) != 0) {
		iTable = 0;
#ifdef BDBSQL_FILE_PER_TABLE
		/* Cannot compact the metadata file */
		goto err;
#endif

		/* Open a DB handle on that table. */
		if ((ret = db_create(&dbp, pDbEnv, 0)) != 0)
			goto err;
		if (pBt->encrypted &&
		    (ret = dbp->set_flags(dbp, DB_ENCRYPT)) != 0)
			goto err;

		tableName = tableNameBuf;
		FIX_TABLENAME(pBt, fileName, tableName);

		/*
		 * We know we're not creating this table, open it using the
		 * family transaction because that keeps the dbreg records out
		 * of the vacuum transaction, reducing pressure on the log
		 * region (since we copy the filename of every open DB handle
		 * into the log region).
		 */
		if ((ret = dbp->open(dbp, pFamilyTxn, fileName, tableName,
		    DB_BTREE, GET_AUTO_COMMIT(pBt, pFamilyTxn), 0)) != 0)
			goto err;
	} else {
		if ((ret = btreeTableNameToId(tableNameBuf,
		    key.size, &iTable)) != 0)
			goto err;

		/* Try to retrieve the matching handle from the cache. */
		rc = btreeFindOrCreateDataTable(p, &iTable, &cached_db, 0);
		if (rc != SQLITE_OK)
			goto err;
		assert(cached_db != NULL && cached_db->dbp != NULL);

		dbp = cached_db->dbp;
		if ((iTable & 1) == 0) {
			/*
			 * Attach the DB handle to a SQLite index, required for
			 * the key comparator to work correctly.  If we can't
			 * find an Index struct, just skip this database.  It
			 * may not be open yet (c.f. whereA-1.7).
			 */
#ifdef BDBSQL_SINGLE_THREAD
			rc = btreeGetKeyInfo(p, iTable,
			    (KeyInfo **)&(dbp->app_private));
#else
			rc = btreeGetKeyInfo(p, iTable,
			    &((TableInfo *)dbp->app_private)->pKeyInfo);
#endif
			if (rc != SQLITE_OK)
				goto err;
		}
	}

	/*
	 * In following db_compact, we use the family transaction because
	 * DB->compact will then auto-commit, and it has built-in smarts
	 * about retrying on deadlock.
	 */
	/* Setup compact_data as configured */
	memset(&compact_data, 0, sizeof(compact_data));
	compact_data.compact_fillpercent = p->fillPercent;

	vacuumMode = sqlite3BtreeGetAutoVacuum(p);
	if (vacuumMode == BTREE_AUTOVACUUM_NONE) {
		ret = dbp->compact(dbp, pFamilyTxn,
		    NULL, NULL, &compact_data, DB_FREE_SPACE, NULL);
	/* Skip current table if we have truncated enough pages */
	} else if (truncatedPages == NULL ||
	    (truncatedPages != NULL && *truncatedPages < p->vacuumPages)) {
		/* Find DBT for db_compact start */
		for (pInfo = p->vacuumInfo, pStart = NULL;
		     pInfo != NULL; pInfo = pInfo->next) {
			if (pInfo->iTable == iTable)
				break;
		}

		/* Create new VacuumInfo for current iTable as needed */
		if (pInfo == NULL) {
			/* Create info for current iTable */
			if ((pInfo = (struct VacuumInfo *)sqlite3_malloc(
			    sizeof(struct VacuumInfo))) == NULL) {
				rc = SQLITE_NOMEM;
				goto err;
			}
			memset(pInfo, 0, sizeof(struct VacuumInfo));
			pInfo->iTable = iTable;
			pInfo->next = p->vacuumInfo;
			p->vacuumInfo = pInfo;
		}
		pStart = &(pInfo->start);

		/* Do page compact for IncrVacuum */
		if (vacuumMode == BTREE_AUTOVACUUM_INCR) {
			/* Do compact with given arguments */
			compact_data.compact_pages = p->vacuumPages;
			if ((ret = dbp->compact(dbp, pFamilyTxn,
				(pStart->data == NULL) ? NULL : pStart,
				NULL, &compact_data, 0, &end)) != 0)
				goto err;

			/* Save current vacuum position */
			if (pStart->data != NULL)
				sqlite3_free(pStart->data);
			memcpy(pStart, &end, sizeof(DBT));
			memset(&end, 0, sizeof(end));

			/* Rewind to start if we reach the end of subdb */
			if (compact_data.compact_pages_free < p->vacuumPages ||
			    p->vacuumPages == 0) {
				if (pStart->data != NULL)
					sqlite3_free(pStart->data);
				memset(pStart, 0, sizeof(DBT));
			}
		}
		/* Because of the one-pass nature of the compaction algorithm,
		 * any unemptied page near the end of the file inhibits
		 * returning pages to the file system.
		 * A repeated call to the DB->compact() method with a low
		 * compact_fillpercent may be used to return pages in this case.
		 */
		memset(&compact_data, 0, sizeof(compact_data));
		compact_data.compact_fillpercent = 1;
		if ((ret = dbp->compact(dbp, pFamilyTxn, NULL, NULL,
			    &compact_data, DB_FREE_SPACE, NULL)) != 0)
			goto err;
		if (truncatedPages != NULL && *truncatedPages > 0)
			*truncatedPages += compact_data.compact_pages_truncated;
	}

err:	/* Free cursor and DBT if run into error */
	if (ret != 0) {
		if (p->compact_cursor != NULL) {
			(void)p->compact_cursor->close(p->compact_cursor);
			p->compact_cursor = NULL;
		}
		if (end.data != NULL)
			sqlite3_free(end.data);
		btreeFreeVacuumInfo(p);
	}

	if (cached_db != NULL) {
#ifdef BDBSQL_SINGLE_THREAD
		if ((app = dbp->app_private) != NULL)
			sqlite3DbFree(p->db, app);
#else
		if (dbp->app_private != NULL &&
		    (app = ((TableInfo *)dbp->app_private)->pKeyInfo) != NULL) {
			sqlite3DbFree(p->db, app);
			((TableInfo *)dbp->app_private)->pKeyInfo = NULL;
		}
#endif
	} else if (dbp != NULL) {
		app = dbp->app_private;
		if ((t_ret = dbp->close(dbp, DB_NOSYNC)) != 0 && ret == 0)
			ret = t_ret;
		if (app != NULL)
			sqlite3DbFree(p->db, app);
	}

	pBt->db_oflags |= was_create;

	return MAP_ERR(rc, ret, p);
}
예제 #6
0
/*
** 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 = ((pId2 && pId2->n>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 char * const azModeName[] = {"delete", "persist", "off", "truncate"};

    if( zRight==0 ){
      eMode = PAGER_JOURNALMODE_QUERY;
    }else{
      int n = strlen(zRight);
      eMode = sizeof(azModeName)/sizeof(azModeName[0]) - 1;
      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_TRUNCATE
              || 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{
#ifndef SQLITE_OMIT_WSD
      if( zRight[0] ){
        int rc;
        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 = sqlite3DbStrDup(0, zRight);
      }else{
        sqlite3_temp_directory = 0;
      }
#endif /* SQLITE_OMIT_WSD */
    }
  }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);
}