SQLite

      rc = fts5CInstIterNext(&p->iter);
    }
  }

  if( p->iRangeEnd>0 && iPos==p->iRangeEnd ){
    fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iEndOff - p->iOff);
    p->iOff = iEndOff;
    if( iPos>=p->iter.iStart && iPos<p->iter.iEnd ){
      fts5HighlightAppend(&rc, p, p->zClose, -1);
    }
  }

  return rc;
}

    ctx.iRangeStart = iBestStart;
    ctx.iRangeEnd = iBestStart + nToken - 1;

    if( iBestStart>0 ){
      fts5HighlightAppend(&rc, &ctx, zEllips, -1);
    }

    /* Advance iterator ctx.iter so that it points to the first coalesced
    ** phrase instance at or following position iBestStart. */
    while( ctx.iter.iStart>=0 && ctx.iter.iStart<iBestStart && rc==SQLITE_OK ){
      rc = fts5CInstIterNext(&ctx.iter);
    }

    if( rc==SQLITE_OK ){
      rc = pApi->xTokenize(pFts, ctx.zIn, ctx.nIn, (void*)&ctx,fts5HighlightCb);
    }
    if( ctx.iRangeEnd>=(nColSize-1) ){
      fts5HighlightAppend(&rc, &ctx, &ctx.zIn[ctx.iOff], ctx.nIn - ctx.iOff);
    }else{
      fts5HighlightAppend(&rc, &ctx, zEllips, -1);

  if( rc==SQLITE_OK ){
    pNew->pRoot->pNear = (Fts5ExprNearset*)sqlite3Fts5MallocZero(&rc, 
        sizeof(Fts5ExprNearset) + sizeof(Fts5ExprPhrase*));
  }
  if( rc==SQLITE_OK ){
    Fts5Colset *pColsetOrig = pOrig->pNode->pNear->pColset;
    if( pColsetOrig ){
      int nByte = sizeof(Fts5Colset) + (pColsetOrig->nCol-1) * sizeof(int);
      Fts5Colset *pColset = (Fts5Colset*)sqlite3Fts5MallocZero(&rc, nByte);
      if( pColset ){ 
        memcpy(pColset, pColsetOrig, nByte);
      }
      pNew->pRoot->pNear->pColset = pColset;
    }
  }

    p->nRead++;
  }

  assert( (pRet==0)==(p->rc!=SQLITE_OK) );
  return pRet;
}


/*
** Release a reference to data record returned by an earlier call to
** fts5DataRead().
*/
static void fts5DataRelease(Fts5Data *pData){
  sqlite3_free(pData);
}

static Fts5Data *fts5LeafRead(Fts5Index *p, i64 iRowid){
  Fts5Data *pRet = fts5DataRead(p, iRowid);
  if( pRet ){
    if( pRet->szLeaf>pRet->nn ){
      p->rc = FTS5_CORRUPT;
      fts5DataRelease(pRet);
      pRet = 0;
    }
  }
  return pRet;
}

static int fts5IndexPrepareStmt(
  Fts5Index *p,
  sqlite3_stmt **ppStmt,
  char *zSql
){
  if( p->rc==SQLITE_OK ){

  Fts5StructureSegment *pSeg = pIter->pSeg;
  fts5DataRelease(pIter->pLeaf);
  pIter->iLeafPgno++;
  if( pIter->pNextLeaf ){
    pIter->pLeaf = pIter->pNextLeaf;
    pIter->pNextLeaf = 0;
  }else if( pIter->iLeafPgno<=pSeg->pgnoLast ){
    pIter->pLeaf = fts5LeafRead(p, 
        FTS5_SEGMENT_ROWID(pSeg->iSegid, pIter->iLeafPgno)
    );
  }else{
    pIter->pLeaf = 0;
  }
  pLeaf = pIter->pLeaf;

      if( (iOff = fts5LeafFirstRowidOff(pLeaf)) && iOff<pLeaf->szLeaf ){
        iOff += sqlite3Fts5GetVarint(&pLeaf->p[iOff], (u64*)&pIter->iRowid);
        pIter->iLeafOffset = iOff;

        if( pLeaf->nn>pLeaf->szLeaf ){
          pIter->iPgidxOff = pLeaf->szLeaf + fts5GetVarint32(
              &pLeaf->p[pLeaf->szLeaf], pIter->iEndofDoclist
          );
        }

      }
      else if( pLeaf->nn>pLeaf->szLeaf ){
        pIter->iPgidxOff = pLeaf->szLeaf + fts5GetVarint32(
            &pLeaf->p[pLeaf->szLeaf], iOff
            );
        pIter->iLeafOffset = iOff;
        pIter->iEndofDoclist = iOff;

      bEndOfPage = 1;
      break;
    }

    iPgidx += fts5GetVarint32(&a[iPgidx], nKeep);
    iTermOff += nKeep;
    iOff = iTermOff;

    if( iOff>=n ){
      p->rc = FTS5_CORRUPT;
      return;
    }

    /* Read the nKeep field of the next term. */
    fts5FastGetVarint32(a, iOff, nKeep);
  }

 search_failed:
  if( bGe==0 ){

  7.1 {X o o X o o o o o} {[X] o o [X] o o o...}
  7.2 {o X o o X o o o o} {o [X] o o [X] o o...}
  7.3 {o o X o o X o o o} {...o [X] o o [X] o o...}
  7.4 {o o o X o o X o o} {...o [X] o o [X] o o}
  7.5 {o o o o X o o X o} {...o o [X] o o [X] o}
  7.6 {o o o o o X o o X} {...o o o [X] o o [X]}

  8.1 {o o o o X o o o o o o o o o o o o o o o o o o o o o X X X o o o}
      {...o o [X] [X] [X] o o...}
} {
  do_snippet_test 1.$tn $doc X $res
}

if {[detail_is_full]} {
  foreach {tn doc res} {
    1.1 {X Y o o o o o} {[X Y] o o o o o}

  CREATE VIRTUAL TABLE t1 USING fts5(x);
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
  WITH ii(i) AS (SELECT 1 UNION SELECT i+1 FROM ii WHERE i<100)
  INSERT INTO t1 SELECT rnddoc(10) FROM ii;
}
set mask [expr 31 << 31]

if 0 {

# Test 1:
#
#   For each page in the t1_data table, open a transaction and DELETE
#   the t1_data entry. Then run:
#
#     * an integrity-check, and

    }
  
    do_execsql_test 1.$tno.$tn.3.$rowid {
      ROLLBACK;
      INSERT INTO t1(t1) VALUES('integrity-check');
    } {}
  }
}

}

# Using the same database as the 1.* tests.
#
# Run N-1 tests, where N is the number of bytes in the rightmost leaf page
# of the fts index. For test $i, truncate the rightmost leafpage to $i
# bytes. Then test both the integrity-check detects the corruption.

      set {} 1
    } {1}

    execsql ROLLBACK
  }

  # do_test 4.$tn.x { expr $nCorrupt>0 } 1


}

set doc [string repeat "A B C " 1000]
do_execsql_test 5.0 {
  CREATE VIRTUAL TABLE x5 USING fts5(tt);
  INSERT INTO x5(x5, rank) VALUES('pgsz', 32);
  WITH ii(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM ii WHERE i<10) 

      CREATE TABLE t1(a, b, c);
      CREATE INDEX t1c ON t1(c);
    }
    vtab { 
      CREATE VIRTUAL TABLE t1 USING fts5(a, b, c);
    }
  } {

    if {$tn=="vtab"} { ifcapable !fts5 break }

    foreach {tn2 rbusql r1 r2} {
      1 {
        CREATE TABLE data0_t1(a, b, c, rbu_rowid, rbu_control);
        INSERT INTO data0_t1 VALUES(15, 15, 15, 4, 0);
        INSERT INTO data0_t1 VALUES(20, 20, 20, 5, 0);
        CREATE TABLE rbu_count(tbl, cnt);

      SELECT * FROM sqlite_master;
    } {
    table t1 t1 2 {CREATE TABLE t1(a, b, c)}
    view v1 v1 0 {CREATE VIEW v1 AS SELECT * FROM t1}
    trigger tr1 t1 0 {CREATE TRIGGER tr1 AFTER INSERT ON t1 BEGIN SELECT 1; END}
    }
  }
}
  
#-------------------------------------------------------------------------
# Test that passing a NULL value as the second argument to 
# sqlite3rbu_vacuum() causes it to:
#
#   * Use <database>-vacuum as the state db, and
#   * Set the state db permissions to the same as those on the db file.
#
db close
if {$::tcl_platform(platform)=="unix"} {
  forcedelete test.db

  sqlite3 db test.db
  do_execsql_test 5.0 {
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
    INSERT INTO t1 VALUES(3, 4);
    INSERT INTO t1 VALUES(5, 6);
    INSERT INTO t1 VALUES(7, 8);
  }
  db close

  foreach {tn perm} {
    1 00755
    2 00666
    3 00644
    4 00444
  } {
    forcedelete test.db-vacuum

    do_test 5.$tn.1 {
      file attributes test.db -permissions $perm
      sqlite3rbu_vacuum rbu test.db
      rbu step
    } {SQLITE_OK}

    do_test 5.$tn.2 { file exists test.db-vacuum } 1
    do_test 5.$tn.3 { file attributes test.db-vacuum -permissions} $perm
    rbu close
  }
}


finish_test

/*
** Open the database handle and attach the RBU database as "rbu". If an
** error occurs, leave an error code and message in the RBU handle.
*/
static void rbuOpenDatabase(sqlite3rbu *p){

  assert( p->rc || (p->dbMain==0 && p->dbRbu==0) );
  assert( p->rc || rbuIsVacuum(p) || p->zTarget!=0 );

  /* Open the RBU database */
  p->dbRbu = rbuOpenDbhandle(p, p->zRbu, 1);

  if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){
    sqlite3_file_control(p->dbRbu, "main", SQLITE_FCNTL_RBUCNT, (void*)p);
    if( p->zState==0 ){
      const char *zFile = sqlite3_db_filename(p->dbRbu, "main");
      p->zState = rbuMPrintf(p, "file://%s-vacuum?modeof=%s", zFile, zFile);
    }
  }

  /* If using separate RBU and state databases, attach the state database to
  ** the RBU db handle now.  */
  if( p->zState ){
    rbuMPrintfExec(p, p->dbRbu, "ATTACH %Q AS stat", p->zState);
    memcpy(p->zStateDb, "stat", 4);

  const char *zTarget, 
  const char *zRbu,
  const char *zState
){
  sqlite3rbu *p;
  size_t nTarget = zTarget ? strlen(zTarget) : 0;
  size_t nRbu = strlen(zRbu);

  size_t nByte = sizeof(sqlite3rbu) + nTarget+1 + nRbu+1;

  p = (sqlite3rbu*)sqlite3_malloc64(nByte);
  if( p ){
    RbuState *pState = 0;

    /* Create the custom VFS. */
    memset(p, 0, sizeof(sqlite3rbu));

        memcpy(p->zTarget, zTarget, nTarget+1);
        pCsr += nTarget+1;
      }
      p->zRbu = pCsr;
      memcpy(p->zRbu, zRbu, nRbu+1);
      pCsr += nRbu+1;
      if( zState ){
        p->zState = rbuMPrintf(p, "%s", zState);

      }
      rbuOpenDatabase(p);
    }

    if( p->rc==SQLITE_OK ){
      pState = rbuLoadState(p);
      assert( pState || p->rc!=SQLITE_OK );

    }

    rbuFreeState(pState);
  }

  return p;
}

/*
** Allocate and return an RBU handle with all fields zeroed except for the
** error code, which is set to SQLITE_MISUSE.
*/
static sqlite3rbu *rbuMisuseError(void){
  sqlite3rbu *pRet;
  pRet = sqlite3_malloc64(sizeof(sqlite3rbu));
  if( pRet ){
    memset(pRet, 0, sizeof(sqlite3rbu));
    pRet->rc = SQLITE_MISUSE;
  }
  return pRet;
}

/*
** Open and return a new RBU handle. 
*/
sqlite3rbu *sqlite3rbu_open(
  const char *zTarget, 
  const char *zRbu,
  const char *zState
){
  if( zTarget==0 || zRbu==0 ){ return rbuMisuseError(); }
  /* TODO: Check that zTarget and zRbu are non-NULL */
  return openRbuHandle(zTarget, zRbu, zState);
}

/*
** Open a handle to begin or resume an RBU VACUUM operation.
*/
sqlite3rbu *sqlite3rbu_vacuum(
  const char *zTarget, 
  const char *zState
){
  if( zTarget==0 ){ return rbuMisuseError(); }
  /* TODO: Check that both arguments are non-NULL */
  return openRbuHandle(0, zTarget, zState);
}

/*
** Return the database handle used by pRbu.
*/

    rbuDeleteVfs(p);
    sqlite3_free(p->aBuf);
    sqlite3_free(p->aFrame);

    rbuEditErrmsg(p);
    rc = p->rc;
    *pzErrmsg = p->zErrmsg;
    sqlite3_free(p->zState);
    sqlite3_free(p);
  }else{
    rc = SQLITE_NOMEM;
    *pzErrmsg = 0;
  }
  return rc;
}

);

/*
** Open an RBU handle to perform an RBU vacuum on database file zTarget.
** An RBU vacuum is similar to SQLite's built-in VACUUM command, except
** that it can be suspended and resumed like an RBU update.
**
** The second argument to this function identifies a database in which 
** to store the state of the RBU vacuum operation if it is suspended. The 
** first time sqlite3rbu_vacuum() is called, to start an RBU vacuum
** operation, the state database should either not exist or be empty
** (contain no tables). If an RBU vacuum is suspended by calling 
** sqlite3rbu_close() on the RBU handle before sqlite3rbu_step() has
** returned SQLITE_DONE, the vacuum state is stored in the state database. 
** The vacuum can be resumed by calling this function to open a new RBU
** handle specifying the same target and state databases.
**
** If the second argument passed to this function is NULL, then the
** name of the state database is "<database>-vacuum", where <database>
** is the name of the target database file. In this case, on UNIX, if the
** state database is not already present in the file-system, it is created
** with the same permissions as the target db is made.
**
** This function does not delete the state database after an RBU vacuum
** is completed, even if it created it. However, if the call to
** sqlite3rbu_close() returns any value other than SQLITE_OK, the contents
** of the state tables within the state database are zeroed. This way,
** the next call to sqlite3rbu_vacuum() opens a handle that starts a 
** new RBU vacuum operation.

  Tcl_Obj *CONST objv[]
){
  sqlite3rbu *pRbu = 0;
  const char *zCmd;
  const char *zTarget;
  const char *zStateDb = 0;

  if( objc!=3 && objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "NAME TARGET-DB ?STATE-DB?");
    return TCL_ERROR;
  }
  zCmd = Tcl_GetString(objv[1]);
  zTarget = Tcl_GetString(objv[2]);
  if( objc==4 ) zStateDb = Tcl_GetString(objv[3]);

  pRbu = sqlite3rbu_vacuum(zTarget, zStateDb);
  Tcl_CreateObjCommand(interp, zCmd, test_sqlite3rbu_cmd, (ClientData)pRbu, 0);
  Tcl_SetObjResult(interp, objv[1]);
  return TCL_OK;
}

  if( NEVER(db->mallocFailed) ) goto exit_rename_table;
  assert( pSrc->nSrc==1 );
  assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );

  pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]);
  if( !pTab ) goto exit_rename_table;
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  zDb = db->aDb[iDb].zDbSName;
  db->flags |= SQLITE_PreferBuiltin;

  /* Get a NULL terminated version of the new table name. */
  zName = sqlite3NameFromToken(db, pName);
  if( !zName ) goto exit_rename_table;

  /* Check that a table or index named 'zName' does not already exist

  if( pParse->nErr || db->mallocFailed ) return;
  assert( v!=0 );
  pNew = pParse->pNewTable;
  assert( pNew );

  assert( sqlite3BtreeHoldsAllMutexes(db) );
  iDb = sqlite3SchemaToIndex(db, pNew->pSchema);
  zDb = db->aDb[iDb].zDbSName;
  zTab = &pNew->zName[16];  /* Skip the "sqlite_altertab_" prefix on the name */
  pCol = &pNew->aCol[pNew->nCol-1];
  pDflt = pCol->pDflt;
  pTab = sqlite3FindTable(db, zTab, zDb);
  assert( pTab );

#ifndef SQLITE_OMIT_AUTHORIZATION

  /* Create new statistic tables if they do not exist, or clear them
  ** if they do already exist.
  */
  for(i=0; i<ArraySize(aTable); i++){
    const char *zTab = aTable[i].zName;
    Table *pStat;
    if( (pStat = sqlite3FindTable(db, zTab, pDb->zDbSName))==0 ){
      if( aTable[i].zCols ){
        /* The sqlite_statN table does not exist. Create it. Note that a 
        ** side-effect of the CREATE TABLE statement is to leave the rootpage 
        ** of the new table in register pParse->regRoot. This is important 
        ** because the OpenWrite opcode below will be needing it. */
        sqlite3NestedParse(pParse,
            "CREATE TABLE %Q.%s(%s)", pDb->zDbSName, zTab, aTable[i].zCols
        );
        aRoot[i] = pParse->regRoot;
        aCreateTbl[i] = OPFLAG_P2ISREG;
      }
    }else{
      /* The table already exists. If zWhere is not NULL, delete all entries 
      ** associated with the table zWhere. If zWhere is NULL, delete the
      ** entire contents of the table. */
      aRoot[i] = pStat->tnum;
      aCreateTbl[i] = 0;
      sqlite3TableLock(pParse, iDb, aRoot[i], 1, zTab);
      if( zWhere ){
        sqlite3NestedParse(pParse,
           "DELETE FROM %Q.%s WHERE %s=%Q",
           pDb->zDbSName, zTab, zWhereType, zWhere
        );
      }else{
        /* The sqlite_stat[134] table already exists.  Delete all rows. */
        sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb);
      }
    }
  }

  }
  assert( sqlite3BtreeHoldsAllMutexes(db) );
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  assert( iDb>=0 );
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
#ifndef SQLITE_OMIT_AUTHORIZATION
  if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0,
      db->aDb[iDb].zDbSName ) ){
    return;
  }
#endif

  /* Establish a read-lock on the table at the shared-cache level. 
  ** Open a read-only cursor on the table. Also allocate a cursor number
  ** to use for scanning indexes (iIdxCur). No index cursor is opened at

        sqlite3DbFree(db, z);
      }
    }
  }else{
    /* Form 3: Analyze the fully qualified table name */
    iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pTableName);
    if( iDb>=0 ){
      zDb = db->aDb[iDb].zDbSName;
      z = sqlite3NameFromToken(db, pTableName);
      if( z ){
        if( (pIdx = sqlite3FindIndex(db, z, zDb))!=0 ){
          analyzeTable(pParse, pIdx->pTable, pIdx);
        }else if( (pTab = sqlite3LocateTable(pParse, 0, z, zDb))!=0 ){
          analyzeTable(pParse, pTab, 0);
        }

    sqlite3DeleteIndexSamples(db, pIdx);
    pIdx->aSample = 0;
#endif
  }

  /* Load new statistics out of the sqlite_stat1 table */
  sInfo.db = db;
  sInfo.zDatabase = db->aDb[iDb].zDbSName;
  if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)!=0 ){
    zSql = sqlite3MPrintf(db, 
        "SELECT tbl,idx,stat FROM %Q.sqlite_stat1", sInfo.zDatabase);
    if( zSql==0 ){
      rc = SQLITE_NOMEM_BKPT;
    }else{
      rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);

    goto attach_error;
  }
  if( !db->autoCommit ){
    zErrDyn = sqlite3MPrintf(db, "cannot ATTACH database within transaction");
    goto attach_error;
  }
  for(i=0; i<db->nDb; i++){
    char *z = db->aDb[i].zDbSName;
    assert( z && zName );
    if( sqlite3StrICmp(z, zName)==0 ){
      zErrDyn = sqlite3MPrintf(db, "database %s is already in use", zName);
      goto attach_error;
    }
  }

#ifndef SQLITE_OMIT_PAGER_PRAGMAS
    sqlite3BtreeSetPagerFlags(aNew->pBt,
                      PAGER_SYNCHRONOUS_FULL | (db->flags & PAGER_FLAGS_MASK));
#endif
    sqlite3BtreeLeave(aNew->pBt);
  }
  aNew->safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
  aNew->zDbSName = sqlite3DbStrDup(db, zName);
  if( rc==SQLITE_OK && aNew->zDbSName==0 ){
    rc = SQLITE_NOMEM_BKPT;
  }


#ifdef SQLITE_HAS_CODEC
  if( rc==SQLITE_OK ){
    extern int sqlite3CodecAttach(sqlite3*, int, const void*, int);

  UNUSED_PARAMETER(NotUsed);

  if( zName==0 ) zName = "";
  for(i=0; i<db->nDb; i++){
    pDb = &db->aDb[i];
    if( pDb->pBt==0 ) continue;
    if( sqlite3StrICmp(pDb->zDbSName, zName)==0 ) break;
  }

  if( i>=db->nDb ){
    sqlite3_snprintf(sizeof(zErr),zErr, "no such database: %s", zName);
    goto detach_error;
  }
  if( i<2 ){

  const Token *pName  /* Name of the view, trigger, or index */
){
  sqlite3 *db;

  db = pParse->db;
  assert( db->nDb>iDb );
  pFix->pParse = pParse;
  pFix->zDb = db->aDb[iDb].zDbSName;
  pFix->pSchema = db->aDb[iDb].pSchema;
  pFix->zType = zType;
  pFix->pName = pName;
  pFix->bVarOnly = (iDb==1);
}

/*

*/
int sqlite3AuthReadCol(
  Parse *pParse,                  /* The parser context */
  const char *zTab,               /* Table name */
  const char *zCol,               /* Column name */
  int iDb                         /* Index of containing database. */
){
  sqlite3 *db = pParse->db;          /* Database handle */
  char *zDb = db->aDb[iDb].zDbSName; /* Schema name of attached database */
  int rc;                            /* Auth callback return code */

  if( db->init.busy ) return SQLITE_OK;
  rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext
#ifdef SQLITE_USER_AUTHENTICATION
                 ,db->auth.zAuthUser
#endif
                );

  ** exists */
  if( db->auth.authLevel<UAUTH_Admin && sqlite3UserAuthTable(zName)!=0 ){
    return 0;
  }
#endif
  for(i=OMIT_TEMPDB; i<db->nDb; i++){
    int j = (i<2) ? i^1 : i;   /* Search TEMP before MAIN */
    if( zDatabase==0 || sqlite3StrICmp(zDatabase, db->aDb[j].zDbSName)==0 ){
      assert( sqlite3SchemaMutexHeld(db, j, 0) );
      p = sqlite3HashFind(&db->aDb[j].pSchema->tblHash, zName);
      if( p ) break;
    }
  }
  return p;
}

/*
** Locate the in-memory structure that describes a particular database
** table given the name of that table and (optionally) the name of the

  u32 flags,
  struct SrcList_item *p
){
  const char *zDb;
  assert( p->pSchema==0 || p->zDatabase==0 );
  if( p->pSchema ){
    int iDb = sqlite3SchemaToIndex(pParse->db, p->pSchema);
    zDb = pParse->db->aDb[iDb].zDbSName;
  }else{
    zDb = p->zDatabase;
  }
  return sqlite3LocateTable(pParse, flags, p->zName, zDb);
}

/*

  int i;
  /* All mutexes are required for schema access.  Make sure we hold them. */
  assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
  for(i=OMIT_TEMPDB; i<db->nDb; i++){
    int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
    Schema *pSchema = db->aDb[j].pSchema;
    assert( pSchema );
    if( zDb && sqlite3StrICmp(zDb, db->aDb[j].zDbSName) ) continue;
    assert( sqlite3SchemaMutexHeld(db, j, 0) );
    p = sqlite3HashFind(&pSchema->idxHash, zName);
    if( p ) break;
  }
  return p;
}

** are never candidates for being collapsed.
*/
void sqlite3CollapseDatabaseArray(sqlite3 *db){
  int i, j;
  for(i=j=2; i<db->nDb; i++){
    struct Db *pDb = &db->aDb[i];
    if( pDb->pBt==0 ){
      sqlite3DbFree(db, pDb->zDbSName);
      pDb->zDbSName = 0;
      continue;
    }
    if( j<i ){
      db->aDb[j] = db->aDb[i];
    }
    j++;
  }

** -1 if the named db cannot be found.
*/
int sqlite3FindDbName(sqlite3 *db, const char *zName){
  int i = -1;         /* Database number */
  if( zName ){
    Db *pDb;
    for(i=(db->nDb-1), pDb=&db->aDb[i]; i>=0; i--, pDb--){
      if( 0==sqlite3StrICmp(pDb->zDbSName, zName) ) break;
    }
  }
  return i;
}

/*
** The token *pName contains the name of a database (either "main" or

  {
    static const u8 aCode[] = {
       SQLITE_CREATE_TABLE,
       SQLITE_CREATE_TEMP_TABLE,
       SQLITE_CREATE_VIEW,
       SQLITE_CREATE_TEMP_VIEW
    };
    char *zDb = db->aDb[iDb].zDbSName;
    if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){
      goto begin_table_error;
    }
    if( !isVirtual && sqlite3AuthCheck(pParse, (int)aCode[isTemp+2*isView],
                                       zName, 0, zDb) ){
      goto begin_table_error;
    }
  }
#endif

  /* Make sure the new table name does not collide with an existing
  ** index or table name in the same database.  Issue an error message if
  ** it does. The exception is if the statement being parsed was passed
  ** to an sqlite3_declare_vtab() call. In that case only the column names
  ** and types will be used, so there is no need to test for namespace
  ** collisions.
  */
  if( !IN_DECLARE_VTAB ){
    char *zDb = db->aDb[iDb].zDbSName;
    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
      goto begin_table_error;
    }
    pTable = sqlite3FindTable(db, zName, zDb);
    if( pTable ){
      if( !noErr ){
        sqlite3ErrorMsg(pParse, "table %T already exists", pName);

    ** SQLITE_MASTER table.  We just need to update that slot with all
    ** the information we've collected.
    */
    sqlite3NestedParse(pParse,
      "UPDATE %Q.%s "
         "SET type='%s', name=%Q, tbl_name=%Q, rootpage=#%d, sql=%Q "
       "WHERE rowid=#%d",
      db->aDb[iDb].zDbSName, SCHEMA_TABLE(iDb),
      zType,
      p->zName,
      p->zName,
      pParse->regRoot,
      zStmt,
      pParse->regRowid
    );
    sqlite3DbFree(db, zStmt);
    sqlite3ChangeCookie(pParse, iDb);

#ifndef SQLITE_OMIT_AUTOINCREMENT
    /* Check to see if we need to create an sqlite_sequence table for
    ** keeping track of autoincrement keys.
    */
    if( p->tabFlags & TF_Autoincrement ){
      Db *pDb = &db->aDb[iDb];
      assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
      if( pDb->pSchema->pSeqTab==0 ){
        sqlite3NestedParse(pParse,
          "CREATE TABLE %Q.sqlite_sequence(name,seq)",
          pDb->zDbSName
        );
      }
    }
#endif

    /* Reparse everything to update our internal data structures */
    sqlite3VdbeAddParseSchemaOp(v, iDb,

  **
  ** The "#NNN" in the SQL is a special constant that means whatever value
  ** is in register NNN.  See grammar rules associated with the TK_REGISTER
  ** token for additional information.
  */
  sqlite3NestedParse(pParse, 
     "UPDATE %Q.%s SET rootpage=%d WHERE #%d AND rootpage=#%d",
     pParse->db->aDb[iDb].zDbSName, SCHEMA_TABLE(iDb), iTable, r1, r1);
#endif
  sqlite3ReleaseTempReg(pParse, r1);
}

/*
** Write VDBE code to erase table pTab and all associated indices on disk.
** Code to update the sqlite_master tables and internal schema definitions

static void sqlite3ClearStatTables(
  Parse *pParse,         /* The parsing context */
  int iDb,               /* The database number */
  const char *zType,     /* "idx" or "tbl" */
  const char *zName      /* Name of index or table */
){
  int i;
  const char *zDbName = pParse->db->aDb[iDb].zDbSName;
  for(i=1; i<=4; i++){
    char zTab[24];
    sqlite3_snprintf(sizeof(zTab),zTab,"sqlite_stat%d",i);
    if( sqlite3FindTable(pParse->db, zTab, zDbName) ){
      sqlite3NestedParse(pParse,
        "DELETE FROM %Q.%s WHERE %s=%Q",
        zDbName, zTab, zType, zName

  ** the table being dropped. This is done before the table is dropped
  ** at the btree level, in case the sqlite_sequence table needs to
  ** move as a result of the drop (can happen in auto-vacuum mode).
  */
  if( pTab->tabFlags & TF_Autoincrement ){
    sqlite3NestedParse(pParse,
      "DELETE FROM %Q.sqlite_sequence WHERE name=%Q",
      pDb->zDbSName, pTab->zName
    );
  }
#endif

  /* Drop all SQLITE_MASTER table and index entries that refer to the
  ** table. The program name loops through the master table and deletes
  ** every row that refers to a table of the same name as the one being
  ** dropped. Triggers are handled separately because a trigger can be
  ** created in the temp database that refers to a table in another
  ** database.
  */
  sqlite3NestedParse(pParse, 
      "DELETE FROM %Q.%s WHERE tbl_name=%Q and type!='trigger'",
      pDb->zDbSName, SCHEMA_TABLE(iDb), pTab->zName);
  if( !isView && !IsVirtual(pTab) ){
    destroyTable(pParse, pTab);
  }

  /* Remove the table entry from SQLite's internal schema and modify
  ** the schema cookie.
  */

  if( IsVirtual(pTab) && sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto exit_drop_table;
  }
#ifndef SQLITE_OMIT_AUTHORIZATION
  {
    int code;
    const char *zTab = SCHEMA_TABLE(iDb);
    const char *zDb = db->aDb[iDb].zDbSName;
    const char *zArg2 = 0;
    if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb)){
      goto exit_drop_table;
    }
    if( isView ){
      if( !OMIT_TEMPDB && iDb==1 ){
        code = SQLITE_DROP_TEMP_VIEW;

  KeyInfo *pKey;                 /* KeyInfo for index */
  int regRecord;                 /* Register holding assembled index record */
  sqlite3 *db = pParse->db;      /* The database connection */
  int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);

#ifndef SQLITE_OMIT_AUTHORIZATION
  if( sqlite3AuthCheck(pParse, SQLITE_REINDEX, pIndex->zName, 0,
      db->aDb[iDb].zDbSName ) ){
    return;
  }
#endif

  /* Require a write-lock on the table to perform this operation */
  sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);

    }
    if( !db->init.busy ){
      if( sqlite3FindTable(db, zName, 0)!=0 ){
        sqlite3ErrorMsg(pParse, "there is already a table named %s", zName);
        goto exit_create_index;
      }
    }
    if( sqlite3FindIndex(db, zName, pDb->zDbSName)!=0 ){
      if( !ifNotExist ){
        sqlite3ErrorMsg(pParse, "index %s already exists", zName);
      }else{
        assert( !db->init.busy );
        sqlite3CodeVerifySchema(pParse, iDb);
      }
      goto exit_create_index;

    if( IN_DECLARE_VTAB ) zName[7]++;
  }

  /* Check for authorization to create an index.
  */
#ifndef SQLITE_OMIT_AUTHORIZATION
  {
    const char *zDb = pDb->zDbSName;
    if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iDb), 0, zDb) ){
      goto exit_create_index;
    }
    i = SQLITE_CREATE_INDEX;
    if( !OMIT_TEMPDB && iDb==1 ) i = SQLITE_CREATE_TEMP_INDEX;
    if( sqlite3AuthCheck(pParse, i, zName, pTab->zName, zDb) ){
      goto exit_create_index;

      zStmt = 0;
    }

    /* Add an entry in sqlite_master for this index
    */
    sqlite3NestedParse(pParse, 
        "INSERT INTO %Q.%s VALUES('index',%Q,%Q,#%d,%Q);",
        db->aDb[iDb].zDbSName, SCHEMA_TABLE(iDb),
        pIndex->zName,
        pTab->zName,
        iMem,
        zStmt
    );
    sqlite3DbFree(db, zStmt);

    goto exit_drop_index;
  }
  iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
#ifndef SQLITE_OMIT_AUTHORIZATION
  {
    int code = SQLITE_DROP_INDEX;
    Table *pTab = pIndex->pTable;
    const char *zDb = db->aDb[iDb].zDbSName;
    const char *zTab = SCHEMA_TABLE(iDb);
    if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
      goto exit_drop_index;
    }
    if( !OMIT_TEMPDB && iDb ) code = SQLITE_DROP_TEMP_INDEX;
    if( sqlite3AuthCheck(pParse, code, pIndex->zName, pTab->zName, zDb) ){
      goto exit_drop_index;
    }
  }
#endif

  /* Generate code to remove the index and from the master table */
  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3BeginWriteOperation(pParse, 1, iDb);
    sqlite3NestedParse(pParse,
       "DELETE FROM %Q.%s WHERE name=%Q AND type='index'",
       db->aDb[iDb].zDbSName, SCHEMA_TABLE(iDb), pIndex->zName
    );
    sqlite3ClearStatTables(pParse, iDb, "idx", pIndex->zName);
    sqlite3ChangeCookie(pParse, iDb);
    destroyRootPage(pParse, pIndex->tnum, iDb);
    sqlite3VdbeAddOp4(v, OP_DropIndex, iDb, 0, 0, pIndex->zName, 0);
  }

** attached database. Otherwise, invoke it for the database named zDb only.
*/
void sqlite3CodeVerifyNamedSchema(Parse *pParse, const char *zDb){
  sqlite3 *db = pParse->db;
  int i;
  for(i=0; i<db->nDb; i++){
    Db *pDb = &db->aDb[i];
    if( pDb->pBt && (!zDb || 0==sqlite3StrICmp(zDb, pDb->zDbSName)) ){
      sqlite3CodeVerifySchema(pParse, i);
    }
  }
}

/*
** Generate VDBE code that prepares for doing an operation that

    }
    sqlite3DbFree(db, zColl);
  }
  iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pObjName);
  if( iDb<0 ) return;
  z = sqlite3NameFromToken(db, pObjName);
  if( z==0 ) return;
  zDb = db->aDb[iDb].zDbSName;
  pTab = sqlite3FindTable(db, z, zDb);
  if( pTab ){
    reindexTable(pParse, pTab, 0);
    sqlite3DbFree(db, z);
    return;
  }
  pIndex = sqlite3FindIndex(db, z, zDb);

  pCsr->pStmt = 0;
  zMaster = pCsr->iDb==1 ? "sqlite_temp_master" : "sqlite_master";
  zSql = sqlite3_mprintf(
      "SELECT 'sqlite_master' AS name, 1 AS rootpage, 'table' AS type"
      "  UNION ALL  "
      "SELECT name, rootpage, type"
      "  FROM \"%w\".%s WHERE rootpage!=0"
      "  ORDER BY name", pTab->db->aDb[pCsr->iDb].zDbSName, zMaster);
  if( zSql==0 ){
    return SQLITE_NOMEM_BKPT;
  }else{
    rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
    sqlite3_free(zSql);
  }

      break;
    case 9:            /* pgsize */
      sqlite3_result_int(ctx, pCsr->szPage);
      break;
    default: {          /* schema */
      sqlite3 *db = sqlite3_context_db_handle(ctx);
      int iDb = pCsr->iDb;
      sqlite3_result_text(ctx, db->aDb[iDb].zDbSName, -1, SQLITE_STATIC);
      break;
    }
  }
  return SQLITE_OK;
}

static int statRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){

  sqlite3 *db = pParse->db;
  int iDb = sqlite3SchemaToIndex(db, pView->pSchema);
  pWhere = sqlite3ExprDup(db, pWhere, 0);
  pFrom = sqlite3SrcListAppend(db, 0, 0, 0);
  if( pFrom ){
    assert( pFrom->nSrc==1 );
    pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);
    pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
    assert( pFrom->a[0].pOn==0 );
    assert( pFrom->a[0].pUsing==0 );
  }
  pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 
                          SF_IncludeHidden, 0, 0);
  sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
  sqlite3Select(pParse, pSel, &dest);

  }

  if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){
    goto delete_from_cleanup;
  }
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  assert( iDb<db->nDb );
  zDb = db->aDb[iDb].zDbSName;
  rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb);
  assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
  if( rcauth==SQLITE_DENY ){
    goto delete_from_cleanup;
  }
  assert(!isView || pTrigger);

  /* Exactly one of regOld and regNew should be non-zero. */
  assert( (regOld==0)!=(regNew==0) );

  /* If foreign-keys are disabled, this function is a no-op. */
  if( (db->flags&SQLITE_ForeignKeys)==0 ) return;

  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  zDb = db->aDb[iDb].zDbSName;

  /* Loop through all the foreign key constraints for which pTab is the
  ** child table (the table that the foreign key definition is part of).  */
  for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){
    Table *pTo;                   /* Parent table of foreign key pFKey */
    Index *pIdx = 0;              /* Index on key columns in pTo */
    int *aiFree = 0;

  pTab = sqlite3SrcListLookup(pParse, pTabList);
  if( pTab==0 ){
    goto insert_cleanup;
  }
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  assert( iDb<db->nDb );
  pDb = &db->aDb[iDb];
  zDb = pDb->zDbSName;
  if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0, zDb) ){
    goto insert_cleanup;
  }
  withoutRowid = !HasRowid(pTab);

  /* Figure out if we have any triggers and if the table being
  ** inserted into is a view

  if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
  sqlite3BtreeLeave(db->aDb[0].pBt);
  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);

  /* The default safety_level for the main database is FULL; for the temp
  ** database it is OFF. This matches the pager layer defaults.  
  */
  db->aDb[0].zDbSName = "main";
  db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
  db->aDb[1].zDbSName = "temp";
  db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;

  db->magic = SQLITE_MAGIC_OPEN;
  if( db->mallocFailed ){
    goto opendb_out;
  }

/*
** Return the Btree pointer identified by zDbName.  Return NULL if not found.
*/
Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
  int i;
  for(i=0; i<db->nDb; i++){
    if( db->aDb[i].pBt
     && (zDbName==0 || sqlite3StrICmp(zDbName, db->aDb[i].zDbSName)==0)
    ){
      return db->aDb[i].pBt;
    }
  }
  return 0;
}

      }
    }
    unixLeaveMutex();
  }
#endif    /* if !OS_VXWORKS */
  return pUnused;
}

/*
** Find the mode, uid and gid of file zFile. 
*/
static int getFileMode(
  const char *zFile,              /* File name */
  mode_t *pMode,                  /* OUT: Permissions of zFile */
  uid_t *pUid,                    /* OUT: uid of zFile. */
  gid_t *pGid                     /* OUT: gid of zFile. */
){
  struct stat sStat;              /* Output of stat() on database file */
  int rc = SQLITE_OK;
  if( 0==osStat(zFile, &sStat) ){
    *pMode = sStat.st_mode & 0777;
    *pUid = sStat.st_uid;
    *pGid = sStat.st_gid;
  }else{
    rc = SQLITE_IOERR_FSTAT;
  }
  return rc;
}

/*
** This function is called by unixOpen() to determine the unix permissions
** to create new files with. If no error occurs, then SQLITE_OK is returned
** and a value suitable for passing as the third argument to open(2) is
** written to *pMode. If an IO error occurs, an SQLite error code is 
** returned and the value of *pMode is not modified.

  int rc = SQLITE_OK;             /* Return Code */
  *pMode = 0;
  *pUid = 0;
  *pGid = 0;
  if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){
    char zDb[MAX_PATHNAME+1];     /* Database file path */
    int nDb;                      /* Number of valid bytes in zDb */


    /* zPath is a path to a WAL or journal file. The following block derives
    ** the path to the associated database file from zPath. This block handles
    ** the following naming conventions:
    **
    **   "<path to db>-journal"
    **   "<path to db>-wal"

      if( nDb==0 || zPath[nDb]=='.' ) return SQLITE_OK;
#endif
      nDb--;
    }
    memcpy(zDb, zPath, nDb);
    zDb[nDb] = '\0';

    rc = getFileMode(zDb, pMode, pUid, pGid);






  }else if( flags & SQLITE_OPEN_DELETEONCLOSE ){
    *pMode = 0600;
  }else if( flags & SQLITE_OPEN_URI ){
    /* If this is a main database file and the file was opened using a URI
    ** filename, check for the "modeof" parameter. If present, interpret
    ** its value as a filename and try to copy the mode, uid and gid from
    ** that file.  */
    const char *z = sqlite3_uri_parameter(zPath, "modeof");
    if( z ){
      rc = getFileMode(z, pMode, pUid, pGid);
    }
  }
  return rc;
}

/*
** Open the file zPath.
** 

  if( minusFlag ){
    zRight = sqlite3MPrintf(db, "-%T", pValue);
  }else{
    zRight = sqlite3NameFromToken(db, pValue);
  }

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

  /* Send an SQLITE_FCNTL_PRAGMA file-control to the underlying VFS
  ** connection.  If it returns SQLITE_OK, then assume that the VFS
  ** handled the pragma and generate a no-op prepared statement.

  case PragTyp_DATABASE_LIST: {
    static const char *azCol[] = { "seq", "name", "file" };
    int i;
    pParse->nMem = 3;
    setAllColumnNames(v, 3, azCol); assert( 3==ArraySize(azCol) );
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pBt==0 ) continue;
      assert( db->aDb[i].zDbSName!=0 );
      sqlite3VdbeMultiLoad(v, 1, "iss",
         i,
         db->aDb[i].zDbSName,
         sqlite3BtreeGetFilename(db->aDb[i].pBt));
      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
    }
  }
  break;

  case PragTyp_COLLATION_LIST: {

      pParse->nMem = MAX( pParse->nMem, 8+mxIdx );

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

    int i;
    setAllColumnNames(v, 2, azCol); assert( 2==ArraySize(azCol) );
    pParse->nMem = 2;
    for(i=0; i<db->nDb; i++){
      Btree *pBt;
      const char *zState = "unknown";
      int j;
      if( db->aDb[i].zDbSName==0 ) continue;
      pBt = db->aDb[i].pBt;
      if( pBt==0 || sqlite3BtreePager(pBt)==0 ){
        zState = "closed";
      }else if( sqlite3_file_control(db, i ? db->aDb[i].zDbSName : 0, 
                                     SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
         zState = azLockName[j];
      }
      sqlite3VdbeMultiLoad(v, 1, "ss", db->aDb[i].zDbSName, zState);
      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
    }
    break;
  }
#endif

#ifdef SQLITE_HAS_CODEC

    /* If the SQL column is blank it means this is an index that
    ** was created to be the PRIMARY KEY or to fulfill a UNIQUE
    ** constraint for a CREATE TABLE.  The index should have already
    ** been created when we processed the CREATE TABLE.  All we have
    ** to do here is record the root page number for that index.
    */
    Index *pIndex;
    pIndex = sqlite3FindIndex(db, argv[0], db->aDb[iDb].zDbSName);
    if( pIndex==0 ){
      /* This can occur if there exists an index on a TEMP table which
      ** has the same name as another index on a permanent index.  Since
      ** the permanent table is hidden by the TEMP table, we can also
      ** safely ignore the index on the permanent table.
      */
      /* Do Nothing */;

  /* Read the schema information out of the schema tables
  */
  assert( db->init.busy );
  {
    char *zSql;
    zSql = sqlite3MPrintf(db, 
        "SELECT name, rootpage, sql FROM \"%w\".%s ORDER BY rowid",
        db->aDb[iDb].zDbSName, zMasterName);
#ifndef SQLITE_OMIT_AUTHORIZATION
    {
      sqlite3_xauth xAuth;
      xAuth = db->xAuth;
      db->xAuth = 0;
#endif
      rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);

  */
  for(i=0; i<db->nDb; i++) {
    Btree *pBt = db->aDb[i].pBt;
    if( pBt ){
      assert( sqlite3BtreeHoldsMutex(pBt) );
      rc = sqlite3BtreeSchemaLocked(pBt);
      if( rc ){
        const char *zDb = db->aDb[i].zDbSName;
        sqlite3ErrorWithMsg(db, rc, "database schema is locked: %s", zDb);
        testcase( db->flags & SQLITE_ReadUncommitted );
        goto end_prepare;
      }
    }
  }

      /* Silently ignore database qualifiers inside CHECK constraints and
      ** partial indices.  Do not raise errors because that might break
      ** legacy and because it does not hurt anything to just ignore the
      ** database name. */
      zDb = 0;
    }else{
      for(i=0; i<db->nDb; i++){
        assert( db->aDb[i].zDbSName );
        if( sqlite3StrICmp(db->aDb[i].zDbSName,zDb)==0 ){
          pSchema = db->aDb[i].pSchema;
          break;
        }
      }
    }
  }

          if( db->mallocFailed ) break;
          if( pSub==0 || (pSub->selFlags & SF_NestedFrom)==0 ){
            pSub = 0;
            if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){
              continue;
            }
            iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
            zSchemaName = iDb>=0 ? db->aDb[iDb].zDbSName : "*";
          }
          for(j=0; j<pTab->nCol; j++){
            char *zName = pTab->aCol[j].zName;
            char *zColname;  /* The computed column name */
            char *zToFree;   /* Malloced string that needs to be freed */
            Token sColname;  /* Computed column name as a token */

** Each database file to be accessed by the system is an instance
** of the following structure.  There are normally two of these structures
** in the sqlite.aDb[] array.  aDb[0] is the main database file and
** aDb[1] is the database file used to hold temporary tables.  Additional
** databases may be attached.
*/
struct Db {
  char *zDbSName;      /* Name of this database. (schema name, not filename) */
  Btree *pBt;          /* The B*Tree structure for this database file */
  u8 safety_level;     /* How aggressive at syncing data to disk */
  u8 bSyncSet;         /* True if "PRAGMA synchronous=N" has been run */
  Schema *pSchema;     /* Pointer to database schema (possibly shared) */
};

/*

    goto trigger_cleanup;
  }
  iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);

#ifndef SQLITE_OMIT_AUTHORIZATION
  {
    int code = SQLITE_CREATE_TRIGGER;
    const char *zDb = db->aDb[iTabDb].zDbSName;
    const char *zDbTrig = isTemp ? db->aDb[1].zDbSName : zDb;
    if( iTabDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
    if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){
      goto trigger_cleanup;
    }
    if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iTabDb),0,zDb)){
      goto trigger_cleanup;
    }

    /* Make an entry in the sqlite_master table */
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto triggerfinish_cleanup;
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    z = sqlite3DbStrNDup(db, (char*)pAll->z, pAll->n);
    sqlite3NestedParse(pParse,
       "INSERT INTO %Q.%s VALUES('trigger',%Q,%Q,0,'CREATE TRIGGER %q')",
       db->aDb[iDb].zDbSName, SCHEMA_TABLE(iDb), zName,
       pTrig->table, z);
    sqlite3DbFree(db, z);
    sqlite3ChangeCookie(pParse, iDb);
    sqlite3VdbeAddParseSchemaOp(v, iDb,
        sqlite3MPrintf(db, "type='trigger' AND name='%q'", zName));
  }

  assert( pName->nSrc==1 );
  zDb = pName->a[0].zDatabase;
  zName = pName->a[0].zName;
  assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
  for(i=OMIT_TEMPDB; i<db->nDb; i++){
    int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
    if( zDb && sqlite3StrICmp(db->aDb[j].zDbSName, zDb) ) continue;
    assert( sqlite3SchemaMutexHeld(db, j, 0) );
    pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName);
    if( pTrigger ) break;
  }
  if( !pTrigger ){
    if( !noErr ){
      sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0);

  assert( iDb>=0 && iDb<db->nDb );
  pTable = tableOfTrigger(pTrigger);
  assert( pTable );
  assert( pTable->pSchema==pTrigger->pSchema || iDb==1 );
#ifndef SQLITE_OMIT_AUTHORIZATION
  {
    int code = SQLITE_DROP_TRIGGER;
    const char *zDb = db->aDb[iDb].zDbSName;
    const char *zTab = SCHEMA_TABLE(iDb);
    if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;
    if( sqlite3AuthCheck(pParse, code, pTrigger->zName, pTable->zName, zDb) ||
      sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
      return;
    }
  }
#endif

  /* Generate code to destroy the database record of the trigger.
  */
  assert( pTable!=0 );
  if( (v = sqlite3GetVdbe(pParse))!=0 ){
    sqlite3NestedParse(pParse,
       "DELETE FROM %Q.%s WHERE name=%Q AND type='trigger'",
       db->aDb[iDb].zDbSName, SCHEMA_TABLE(iDb), pTrigger->zName
    );
    sqlite3ChangeCookie(pParse, iDb);
    sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->zName, 0);
  }
}

/*

  pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
  if( pSrc ){
    assert( pSrc->nSrc>0 );
    pSrc->a[pSrc->nSrc-1].zName = sqlite3DbStrDup(db, pStep->zTarget);
    iDb = sqlite3SchemaToIndex(db, pStep->pTrig->pSchema);
    if( iDb==0 || iDb>=2 ){
      const char *zDb;
      assert( iDb<db->nDb );
      zDb = db->aDb[iDb].zDbSName;
      pSrc->a[pSrc->nSrc-1].zDatabase =  sqlite3DbStrDup(db, zDb);
    }
  }
  return pSrc;
}

/*
** Generate VDBE code for the statements inside the body of a single 

      }
    }
#ifndef SQLITE_OMIT_AUTHORIZATION
    {
      int rc;
      rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
                            j<0 ? "ROWID" : pTab->aCol[j].zName,
                            db->aDb[iDb].zDbSName);
      if( rc==SQLITE_DENY ){
        goto update_cleanup;
      }else if( rc==SQLITE_IGNORE ){
        aXRef[j] = -1;
      }
    }
#endif

    zSql = "ATTACH ':memory:' AS vacuum_db;";
  }else{
    zSql = "ATTACH '' AS vacuum_db;";
  }
  rc = execSql(db, pzErrMsg, zSql);
  if( db->nDb>nDb ){
    pDb = &db->aDb[db->nDb-1];
    assert( strcmp(pDb->zDbSName,"vacuum_db")==0 );
  }
  if( rc!=SQLITE_OK ) goto end_of_vacuum;
  pTemp = db->aDb[db->nDb-1].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

    assert( pOp->opcode==OP_InsertInt );
    x.nKey = pOp->p3;
  }

  if( pOp->p4type==P4_TABLE && HAS_UPDATE_HOOK(db) ){
    assert( pC->isTable );
    assert( pC->iDb>=0 );
    zDb = db->aDb[pC->iDb].zDbSName;
    pTab = pOp->p4.pTab;
    assert( HasRowid(pTab) );
    op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
  }else{
    pTab = 0; /* Not needed.  Silence a comiler warning. */
    zDb = 0;  /* Not needed.  Silence a compiler warning. */
  }

  ** the name of the db to pass as to it. Also set local pTab to a copy
  ** of p4.pTab. Finally, if p5 is true, indicating that this cursor was
  ** last moved with OP_Next or OP_Prev, not Seek or NotFound, set 
  ** VdbeCursor.movetoTarget to the current rowid.  */
  if( pOp->p4type==P4_TABLE && HAS_UPDATE_HOOK(db) ){
    assert( pC->iDb>=0 );
    assert( pOp->p4.pTab!=0 );
    zDb = db->aDb[pC->iDb].zDbSName;
    pTab = pOp->p4.pTab;
    if( (pOp->p5 & OPFLAG_SAVEPOSITION)!=0 && pC->isTable ){
      pC->movetoTarget = sqlite3BtreeIntegerKey(pC->uc.pCursor);
    }
  }else{
    zDb = 0;   /* Not needed.  Silence a compiler warning. */
    pTab = 0;  /* Not needed.  Silence a compiler warning. */

  /* Used to be a conditional */ {
    zMaster = SCHEMA_TABLE(iDb);
    initData.db = db;
    initData.iDb = pOp->p1;
    initData.pzErrMsg = &p->zErrMsg;
    zSql = sqlite3MPrintf(db,
       "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s ORDER BY rowid",
       db->aDb[iDb].zDbSName, zMaster, pOp->p4.z);
    if( zSql==0 ){
      rc = SQLITE_NOMEM_BKPT;
    }else{
      assert( db->init.busy==0 );
      db->init.busy = 1;
      initData.rc = SQLITE_OK;
      assert( !db->mallocFailed );

  }
#ifdef SQLITE_USE_FCNTL_TRACE
  zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql);
  if( zTrace ){
    int i;
    for(i=0; i<db->nDb; i++){
      if( DbMaskTest(p->btreeMask, i)==0 ) continue;
      sqlite3_file_control(db, db->aDb[i].zDbSName, SQLITE_FCNTL_TRACE, zTrace);
    }
  }
#endif /* SQLITE_USE_FCNTL_TRACE */
#ifdef SQLITE_DEBUG
  if( (db->flags & SQLITE_SqlTrace)!=0
   && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
  ){

    Btree *pBt = db->aDb[i].pBt;
    if( pBt ){
      int nEntry;
      sqlite3BtreeEnter(pBt);
      nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));
      sqlite3BtreeLeave(pBt);
      if( db->xWalCallback && nEntry>0 && rc==SQLITE_OK ){
        rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zDbSName, nEntry);
      }
    }
  }
#endif
  return rc;
}

        pParse->zErrMsg = 0;
      }
      rc = SQLITE_ERROR;
      sqlite3BtreeLeaveAll(db);
      goto blob_open_out;
    }
    pBlob->pTab = pTab;
    pBlob->zDb = db->aDb[sqlite3SchemaToIndex(db, pTab->pSchema)].zDbSName;

    /* Now search pTab for the exact column. */
    for(iCol=0; iCol<pTab->nCol; iCol++) {
      if( sqlite3StrICmp(pTab->aCol[iCol].zName, zColumn)==0 ){
        break;
      }
    }

  /* Creating a virtual table invokes the authorization callback twice.
  ** The first invocation, to obtain permission to INSERT a row into the
  ** sqlite_master table, has already been made by sqlite3StartTable().
  ** The second call, to obtain permission to create the table, is made now.
  */
  if( pTable->azModuleArg ){
    sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName, 
            pTable->azModuleArg[0], pParse->db->aDb[iDb].zDbSName);
  }
#endif
}

/*
** This routine takes the module argument that has been accumulating
** in pParse->zArg[] and appends it to the list of arguments on the

    ** by sqlite3StartTable().
    */
    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
    sqlite3NestedParse(pParse,
      "UPDATE %Q.%s "
         "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
       "WHERE rowid=#%d",
      db->aDb[iDb].zDbSName, SCHEMA_TABLE(iDb),
      pTab->zName,
      pTab->zName,
      zStmt,
      pParse->regRowid
    );
    sqlite3DbFree(db, zStmt);
    v = sqlite3GetVdbe(pParse);

    sqlite3DbFree(db, zModuleName);
    return SQLITE_NOMEM_BKPT;
  }
  pVTable->db = db;
  pVTable->pMod = pMod;

  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  pTab->azModuleArg[1] = db->aDb[iDb].zDbSName;

  /* Invoke the virtual table constructor */
  assert( &db->pVtabCtx );
  assert( xConstruct );
  sCtx.pTab = pTab;
  sCtx.pVTable = pVTable;
  sCtx.pPrior = db->pVtabCtx;

*/
int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){
  int rc = SQLITE_OK;
  Table *pTab;
  Module *pMod;
  const char *zMod;

  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName);
  assert( pTab && (pTab->tabFlags & TF_Virtual)!=0 && !pTab->pVTable );

  /* Locate the required virtual table module */
  zMod = pTab->azModuleArg[0];
  pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);

  /* If the module has been registered and includes a Create method, 

**
** This call is a no-op if zTab is not a virtual table.
*/
int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab){
  int rc = SQLITE_OK;
  Table *pTab;

  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName);
  if( pTab!=0 && ALWAYS(pTab->pVTable!=0) ){
    VTable *p;
    int (*xDestroy)(sqlite3_vtab *);
    for(p=pTab->pVTable; p; p=p->pNext){
      assert( p->pVtab );
      if( p->pVtab->nRef>0 ){
        return SQLITE_LOCKED;

  int prec;                /* Precedence if defined (-1 otherwise) */
  enum e_assoc assoc;      /* Associativity if precedence is defined */
  char *firstset;          /* First-set for all rules of this symbol */
  Boolean lambda;          /* True if NT and can generate an empty string */
  int useCnt;              /* Number of times used */
  char *destructor;        /* Code which executes whenever this symbol is
                           ** popped from the stack during error processing */
  int destLineno;          /* Line number for start of destructor.  Set to
                           ** -1 for duplicate destructors. */
  char *datatype;          /* The data type of information held by this
                           ** object. Only used if type==NONTERMINAL */
  int dtnum;               /* The data type number.  In the parser, the value
                           ** stack is a union.  The .yy%d element of this
                           ** union is the correct data type for this object */
  /* The following fields are used by MULTITERMINALs only */
  int nsubsym;             /* Number of constituent symbols in the MULTI */

      emit_destructor_code(out,dflt_sp,lemp,&lineno);
    }
    fprintf(out,"      break;\n"); lineno++;
  }
  for(i=0; i<lemp->nsymbol; i++){
    struct symbol *sp = lemp->symbols[i];
    if( sp==0 || sp->type==TERMINAL || sp->destructor==0 ) continue;
    if( sp->destLineno<0 ) continue;  /* Already emitted */
    fprintf(out,"    case %d: /* %s */\n", sp->index, sp->name); lineno++;

    /* Combine duplicate destructors into a single case */
    for(j=i+1; j<lemp->nsymbol; j++){
      struct symbol *sp2 = lemp->symbols[j];
      if( sp2 && sp2->type!=TERMINAL && sp2->destructor
          && sp2->dtnum==sp->dtnum
          && strcmp(sp->destructor,sp2->destructor)==0 ){
         fprintf(out,"    case %d: /* %s */\n",
                 sp2->index, sp2->name); lineno++;
         sp2->destLineno = -1;  /* Avoid emitting this destructor again */
      }
    }

    emit_destructor_code(out,lemp->symbols[i],lemp,&lineno);
    fprintf(out,"      break;\n"); lineno++;
  }
  tplt_xfer(lemp->name,in,out,&lineno);