Fossil

**    CREATE INDEX
**    CREATE UNIQUE INDEX
**    CREATE VIEW
**    CREATE TRIGGER
**    CREATE VIRTUAL TABLE
**
** This UDF is used by the .schema command to insert the schema name of
** attached databases into the middle of the sqlite_schema.sql field.
*/
static void shellAddSchemaName(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  static const char *aPrefix[] = {

          char *zSql = 0;
          const char *zSep = "";
          sqlite3_prepare_v2(pCur->db, "PRAGMA database_list", -1, &pS2, 0);
          while( sqlite3_step(pS2)==SQLITE_ROW ){
            const char *zDb = (const char*)sqlite3_column_text(pS2, 1);
            zSql = sqlite3_mprintf(
               "%z%s"
               "SELECT name FROM \"%w\".sqlite_schema",
               zSql, zSep, zDb
            );
            if( zSql==0 ) return SQLITE_NOMEM;
            zSep = " UNION ";
          }
          sqlite3_finalize(pS2);
          sqlite3_prepare_v2(pCur->db, zSql, -1, &pCur->pStmt, 0);

          char *zSql = 0;
          const char *zSep = "";
          sqlite3_prepare_v2(pCur->db, "PRAGMA database_list", -1, &pS2, 0);
          while( sqlite3_step(pS2)==SQLITE_ROW ){
            const char *zDb = (const char*)sqlite3_column_text(pS2, 1);
            zSql = sqlite3_mprintf(
               "%z%s"
               "SELECT pti.name FROM \"%w\".sqlite_schema AS sm"
                       " JOIN pragma_table_info(sm.name,%Q) AS pti"
               " WHERE sm.type='table'",
               zSql, zSep, zDb, zDb
            );
            if( zSql==0 ) return SQLITE_NOMEM;
            zSep = " UNION ";
          }

  char **pzErr
){
  static const char *zInt = UNIQUE_TABLE_NAME;
  static const char *zDrop = "DROP TABLE " UNIQUE_TABLE_NAME;
  IdxTable *pTab = pWrite->pTab;
  const char *zTab = pTab->zName;
  const char *zSql = 
    "SELECT 'CREATE TEMP' || substr(sql, 7) FROM sqlite_schema "
    "WHERE tbl_name = %Q AND type IN ('table', 'trigger') "
    "ORDER BY type;";
  sqlite3_stmt *pSelect = 0;
  int rc = SQLITE_OK;
  char *zWrite = 0;

  /* Create the table and its triggers in the temp schema */

  /* For each table in the main db schema:
  **
  **   1) Add an entry to the p->pTable list, and
  **   2) Create the equivalent virtual table in dbv.
  */
  rc = idxPrepareStmt(p->db, &pSchema, pzErrmsg,
      "SELECT type, name, sql, 1 FROM sqlite_schema "
      "WHERE type IN ('table','view') AND name NOT LIKE 'sqlite_%%' "
      " UNION ALL "
      "SELECT type, name, sql, 2 FROM sqlite_schema "
      "WHERE type = 'trigger'"
      "  AND tbl_name IN(SELECT name FROM sqlite_schema WHERE type = 'view') "
      "ORDER BY 4, 1"
  );
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSchema) ){
    const char *zType = (const char*)sqlite3_column_text(pSchema, 0);
    const char *zName = (const char*)sqlite3_column_text(pSchema, 1);
    const char *zSql = (const char*)sqlite3_column_text(pSchema, 2);

  }
}

static int idxLargestIndex(sqlite3 *db, int *pnMax, char **pzErr){
  int rc = SQLITE_OK;
  const char *zMax = 
    "SELECT max(i.seqno) FROM "
    "  sqlite_schema AS s, "
    "  pragma_index_list(s.name) AS l, "
    "  pragma_index_info(l.name) AS i "
    "WHERE s.type = 'table'";
  sqlite3_stmt *pMax = 0;

  *pnMax = 0;
  rc = idxPrepareStmt(db, &pMax, pzErr, zMax);

  i64 iPrev = -100000;
  sqlite3_stmt *pAllIndex = 0;
  sqlite3_stmt *pIndexXInfo = 0;
  sqlite3_stmt *pWrite = 0;

  const char *zAllIndex =
    "SELECT s.rowid, s.name, l.name FROM "
    "  sqlite_schema AS s, "
    "  pragma_index_list(s.name) AS l "
    "WHERE s.type = 'table'";
  const char *zIndexXInfo = 
    "SELECT name, coll FROM pragma_index_xinfo(?) WHERE key";
  const char *zWrite = "INSERT INTO sqlite_stat1 VALUES(?, ?, ?)";

  /* If iSample==0, no sqlite_stat1 data is required. */

  for(i=0; i<pCtx->nSlot; i++){
    sqlite3_free(pCtx->aSlot[i].z);
  }
  sqlite3_free(pCtx);

  if( rc==SQLITE_OK ){
    rc = sqlite3_exec(p->dbm, "ANALYZE sqlite_schema", 0, 0, 0);
  }

  sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
  return rc;
}

/*

  }
  

  /* Copy the entire schema of database [db] into [dbm]. */
  if( rc==SQLITE_OK ){
    sqlite3_stmt *pSql;
    rc = idxPrintfPrepareStmt(pNew->db, &pSql, pzErrmsg, 
        "SELECT sql FROM sqlite_schema WHERE name NOT LIKE 'sqlite_%%'"
        " AND sql NOT LIKE 'CREATE VIRTUAL %%'"
    );
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
      const char *zSql = (const char*)sqlite3_column_text(pSql, 0);
      rc = sqlite3_exec(pNew->dbm, zSql, 0, 0, pzErrmsg);
    }
    idxFinalize(&rc, pSql);

    "CREATE TEMP TABLE [_shell$self](op,cmd,ans);\n"
    "INSERT INTO [_shell$self](rowid,op,cmd)\n"
    "  VALUES(coalesce((SELECT (max(tno)+100)/10 FROM selftest),10),\n"
    "         'memo','Tests generated by --init');\n"
    "INSERT INTO [_shell$self]\n"
    "  SELECT 'run',\n"
    "    'SELECT hex(sha3_query(''SELECT type,name,tbl_name,sql "
                                 "FROM sqlite_schema ORDER BY 2'',224))',\n"
    "    hex(sha3_query('SELECT type,name,tbl_name,sql "
                          "FROM sqlite_schema ORDER BY 2',224));\n"
    "INSERT INTO [_shell$self]\n"
    "  SELECT 'run',"
    "    'SELECT hex(sha3_query(''SELECT * FROM \"' ||"
    "        printf('%w',name) || '\" NOT INDEXED'',224))',\n"
    "    hex(sha3_query(printf('SELECT * FROM \"%w\" NOT INDEXED',name),224))\n"
    "  FROM (\n"
    "    SELECT name FROM sqlite_schema\n"
    "     WHERE type='table'\n"
    "       AND name<>'selftest'\n"
    "       AND coalesce(rootpage,0)>0\n"
    "  )\n"
    " ORDER BY name;\n"
    "INSERT INTO [_shell$self]\n"
    "  VALUES('run','PRAGMA integrity_check','ok');\n"

                         &azData, &nRow, &nColumn, &zMsg);
  if( rc ){
    utf8_printf(p->out, "ERROR: %s\n", zMsg);
    sqlite3_free(zMsg);
    sqlite3_free_table(azData);
    return;
  }
  if( nRow==0 || nColumn==0 ) goto columnar_end;



  if( nColumn>p->nWidth ){
    p->colWidth = realloc(p->colWidth, nColumn*2*sizeof(int));
    if( p->colWidth==0 ) shell_out_of_memory();
    for(i=p->nWidth; i<nColumn; i++) p->colWidth[i] = 0;
    p->nWidth = nColumn;
    p->actualWidth = &p->colWidth[nColumn];
  }

  for(i=0; i<nTotal; i++){
    z = azData[i];
    if( z==0 ) z = p->nullValue;
    n = strlenChar(z);
    j = i%nColumn;
    if( n>p->actualWidth[j] ) p->actualWidth[j] = n;
  }
  if( seenInterrupt ) goto columnar_end;
  switch( p->cMode ){
    case MODE_Column: {
      colSep = "  ";
      rowSep = "\n";
      if( p->showHeader ){
        for(i=0; i<nColumn; i++){
          w = p->actualWidth[i];

    if( z==0 ) z = p->nullValue;
    w = p->actualWidth[j];
    if( p->colWidth[j]<0 ) w = -w;
    utf8_width_print(p->out, w, z);
    if( j==nColumn-1 ){
      utf8_printf(p->out, "%s", rowSep);
      j = -1;
      if( seenInterrupt ) goto columnar_end;
    }else{
      utf8_printf(p->out, "%s", colSep);
    }
  }
  if( p->cMode==MODE_Table ){
    print_row_separator(p, nColumn, "+");
  }else if( p->cMode==MODE_Box ){
    print_box_row_separator(p, nColumn, BOX_12, BOX_124, BOX_14);
  }
columnar_end:
  if( seenInterrupt ){
    utf8_printf(p->out, "Interrupt\n");
  }
  sqlite3_free_table(azData);
}

/*
** Run a prepared statement
*/
static void exec_prepared_stmt(

  zTable = azArg[0];
  zType = azArg[1];
  zSql = azArg[2];

  if( strcmp(zTable, "sqlite_sequence")==0 ){
    raw_printf(p->out, "DELETE FROM sqlite_sequence;\n");
  }else if( sqlite3_strglob("sqlite_stat?", zTable)==0 ){
    raw_printf(p->out, "ANALYZE sqlite_schema;\n");
  }else if( strncmp(zTable, "sqlite_", 7)==0 ){
    return 0;
  }else if( strncmp(zSql, "CREATE VIRTUAL TABLE", 20)==0 ){
    char *zIns;
    if( !p->writableSchema ){
      raw_printf(p->out, "PRAGMA writable_schema=ON;\n");
      p->writableSchema = 1;
    }
    zIns = sqlite3_mprintf(
       "INSERT INTO sqlite_schema(type,name,tbl_name,rootpage,sql)"
       "VALUES('table','%q','%q',0,'%q');",
       zTable, zTable, zSql);
    utf8_printf(p->out, "%s\n", zIns);
    sqlite3_free(zIns);
    return 0;
  }else{
    printSchemaLine(p->out, zSql, ";\n");

  "     list                     List currently open session names",
  "     open DB NAME             Open a new session on DB",
  "     patchset FILE            Write a patchset into FILE",
  "   If ?NAME? is omitted, the first defined session is used.",
#endif
  ".sha3sum ...             Compute a SHA3 hash of database content",
  "    Options:",
  "      --schema              Also hash the sqlite_schema table",
  "      --sha3-224            Use the sha3-224 algorithm",
  "      --sha3-256            Use the sha3-256 algorithm (default)",
  "      --sha3-384            Use the sha3-384 algorithm",
  "      --sha3-512            Use the sha3-512 algorithm",
  "    Any other argument is a LIKE pattern for tables to hash",
#ifndef SQLITE_NOHAVE_SYSTEM
  ".shell CMD ARGS...       Run CMD ARGS... in a system shell",

}


/*
** Try to transfer all rows of the schema that match zWhere.  For
** each row, invoke xForEach() on the object defined by that row.
** If an error is encountered while moving forward through the
** sqlite_schema table, try again moving backwards.
*/
static void tryToCloneSchema(
  ShellState *p,
  sqlite3 *newDb,
  const char *zWhere,
  void (*xForEach)(ShellState*,sqlite3*,const char*)
){
  sqlite3_stmt *pQuery = 0;
  char *zQuery = 0;
  int rc;
  const unsigned char *zName;
  const unsigned char *zSql;
  char *zErrMsg = 0;

  zQuery = sqlite3_mprintf("SELECT name, sql FROM sqlite_schema"
                           " WHERE %s", zWhere);
  rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
  if( rc ){
    utf8_printf(stderr, "Error: (%d) %s on [%s]\n",
                    sqlite3_extended_errcode(p->db), sqlite3_errmsg(p->db),
                    zQuery);
    goto end_schema_xfer;

      xForEach(p, newDb, (const char*)zName);
    }
    printf("done\n");
  }
  if( rc!=SQLITE_DONE ){
    sqlite3_finalize(pQuery);
    sqlite3_free(zQuery);
    zQuery = sqlite3_mprintf("SELECT name, sql FROM sqlite_schema"
                             " WHERE %s ORDER BY rowid DESC", zWhere);
    rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
    if( rc ){
      utf8_printf(stderr, "Error: (%d) %s on [%s]\n",
                      sqlite3_extended_errcode(p->db), sqlite3_errmsg(p->db),
                      zQuery);
      goto end_schema_xfer;

        if( val==2 ) raw_printf(p->out, " (utf16le)");
        if( val==3 ) raw_printf(p->out, " (utf16be)");
      }
    }
    raw_printf(p->out, "\n");
  }
  if( zDb==0 ){
    zSchemaTab = sqlite3_mprintf("main.sqlite_schema");
  }else if( strcmp(zDb,"temp")==0 ){
    zSchemaTab = sqlite3_mprintf("%s", "sqlite_temp_schema");
  }else{
    zSchemaTab = sqlite3_mprintf("\"%w\".sqlite_schema", zDb);
  }
  for(i=0; i<ArraySize(aQuery); i++){
    char *zSql = sqlite3_mprintf(aQuery[i].zSql, zSchemaTab);
    int val = db_int(p, zSql);
    sqlite3_free(zSql);
    utf8_printf(p->out, "%-20s %d\n", aQuery[i].zName, val);
  }

    "  || ' ON ' || quote(s.name) || '('"
    "  || group_concat(quote(f.[from]) ||"
    "        fkey_collate_clause("
    "          f.[table], COALESCE(f.[to], p.[name]), s.name, f.[from]), ', ')"
    "  || ');'"
    ", "
    "     f.[table] "
    "FROM sqlite_schema AS s, pragma_foreign_key_list(s.name) AS f "
    "LEFT JOIN pragma_table_info AS p ON (pk-1=seq AND p.arg=f.[table]) "
    "GROUP BY s.name, f.id "
    "ORDER BY (CASE WHEN ? THEN f.[table] ELSE s.name END)"
  ;
  const char *zGlobIPK = "SEARCH TABLE * USING INTEGER PRIMARY KEY (rowid=?)";

  for(i=2; i<nArg; i++){

    if( rc!=SQLITE_OK || nSqlCol<nCol ){
      goto finished;
    }

    shellPreparePrintf(dbtmp, &rc, &pStmt, 
      "SELECT ("
      "  SELECT substr(data,1,1)==X'0D' FROM sqlite_dbpage WHERE pgno=rootpage"
      ") FROM sqlite_schema WHERE name = %Q", zName
    );
    if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      bSqlIntkey = sqlite3_column_int(pStmt, 0);
    }
    shellFinalize(&rc, pStmt);

    if( bIntkey==bSqlIntkey ){

    pTab = 0;
  }
  return pTab;
}

/*
** This function is called to search the schema recovered from the
** sqlite_schema table of the (possibly) corrupt database as part
** of a ".recover" command. Specifically, for a table with root page
** iRoot and at least nCol columns. Additionally, if bIntkey is 0, the
** table must be a WITHOUT ROWID table, or if non-zero, not one of
** those.
**
** If a table is found, a (RecoverTable*) object is returned. Or, if
** no such table is found, but bIntkey is false and iRoot is the 

    ") "
    "FROM pages WHERE maxlen IS NOT NULL AND i NOT IN freelist;"
    "UPDATE recovery.map AS o SET intkey = ("
    "  SELECT substr(data, 1, 1)==X'0D' FROM sqlite_dbpage WHERE pgno=o.pgno"
    ");"

    /* Extract data from page 1 and any linked pages into table
    ** recovery.schema. With the same schema as an sqlite_schema table.  */
    "CREATE TABLE recovery.schema(type, name, tbl_name, rootpage, sql);"
    "INSERT INTO recovery.schema SELECT "
    "  max(CASE WHEN field=0 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=1 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=2 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=3 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=4 THEN value ELSE NULL END)"

        "WHERE sql NOT LIKE 'create table%'", &pStmt
    );
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      const char *zSql = (const char*)sqlite3_column_text(pStmt, 0);
      if( sqlite3_strnicmp(zSql, "create virt", 11)==0 ){
        const char *zName = (const char*)sqlite3_column_text(pStmt, 1);
        char *zPrint = shellMPrintf(&rc, 
          "INSERT INTO sqlite_schema VALUES('table', %Q, %Q, 0, %Q)",
          zName, zName, zSql
        );
        raw_printf(pState->out, "%s;\n", zPrint);
        sqlite3_free(zPrint);
      }else{
        raw_printf(pState->out, "%s;\n", zSql);
      }

    ** which causes immediate foreign key constraints to be violated.
    ** So disable foreign-key constraint enforcement to prevent problems. */
    raw_printf(p->out, "PRAGMA foreign_keys=OFF;\n");
    raw_printf(p->out, "BEGIN TRANSACTION;\n");
    p->writableSchema = 0;
    p->showHeader = 0;
    /* Set writable_schema=ON since doing so forces SQLite to initialize
    ** as much of the schema as it can even if the sqlite_schema table is
    ** corrupt. */
    sqlite3_exec(p->db, "SAVEPOINT dump; PRAGMA writable_schema=ON", 0, 0, 0);
    p->nErr = 0;
    if( zLike==0 ) zLike = sqlite3_mprintf("true");
    zSql = sqlite3_mprintf(
      "SELECT name, type, sql FROM sqlite_schema "
      "WHERE (%s) AND type=='table'"
      "  AND sql NOT NULL"
      " ORDER BY tbl_name='sqlite_sequence', rowid",
      zLike
    );
    run_schema_dump_query(p,zSql);
    sqlite3_free(zSql);
    zSql = sqlite3_mprintf(
      "SELECT sql FROM sqlite_schema "
      "WHERE (%s) AND sql NOT NULL"
      "  AND type IN ('index','trigger','view')",
      zLike
    );
    run_table_dump_query(p, zSql);
    sqlite3_free(zSql);
    sqlite3_free(zLike);

      }else if( strcmp(azArg[1],"test")==0 ){
        p->autoEQP = AUTOEQP_on;
        p->autoEQPtest = 1;
      }else if( strcmp(azArg[1],"trace")==0 ){
        p->autoEQP = AUTOEQP_full;
        p->autoEQPtrace = 1;
        open_db(p, 0);
        sqlite3_exec(p->db, "SELECT name FROM sqlite_schema LIMIT 1", 0, 0, 0);
        sqlite3_exec(p->db, "PRAGMA vdbe_trace=ON;", 0, 0, 0);
#endif
      }else{
        p->autoEQP = (u8)booleanValue(azArg[1]);
      }
    }else{
      raw_printf(stderr, "Usage: .eqp off|on|trace|trigger|full\n");

      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    rc = sqlite3_exec(p->db,
       "SELECT sql FROM"
       "  (SELECT sql sql, type type, tbl_name tbl_name, name name, rowid x"
       "     FROM sqlite_schema UNION ALL"
       "   SELECT sql, type, tbl_name, name, rowid FROM sqlite_temp_schema) "
       "WHERE type!='meta' AND sql NOTNULL AND name NOT LIKE 'sqlite_%' "
       "ORDER BY rowid",
       callback, &data, &zErrMsg
    );
    if( rc==SQLITE_OK ){
      sqlite3_stmt *pStmt;
      rc = sqlite3_prepare_v2(p->db,
               "SELECT rowid FROM sqlite_schema"
               " WHERE name GLOB 'sqlite_stat[134]'",
               -1, &pStmt, 0);
      doStats = sqlite3_step(pStmt)==SQLITE_ROW;
      sqlite3_finalize(pStmt);
    }
    if( doStats==0 ){
      raw_printf(p->out, "/* No STAT tables available */\n");
    }else{
      raw_printf(p->out, "ANALYZE sqlite_schema;\n");
      sqlite3_exec(p->db, "SELECT 'ANALYZE sqlite_schema'",
                   callback, &data, &zErrMsg);
      data.cMode = data.mode = MODE_Insert;
      data.zDestTable = "sqlite_stat1";
      shell_exec(&data, "SELECT * FROM sqlite_stat1", &zErrMsg);
      data.zDestTable = "sqlite_stat4";
      shell_exec(&data, "SELECT * FROM sqlite_stat4", &zErrMsg);
      raw_printf(p->out, "ANALYZE sqlite_schema;\n");
    }
  }else

  if( c=='h' && strncmp(azArg[0], "headers", n)==0 ){
    if( nArg==2 ){
      p->showHeader = booleanValue(azArg[1]);
      p->shellFlgs |= SHFLG_HeaderSet;

    }
    open_db(p, 0);
    if( nArg==2 ){
      sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->db, "main", 0, 1);
      goto meta_command_exit;
    }
    zSql = sqlite3_mprintf(
      "SELECT rootpage, 0 FROM sqlite_schema"
      " WHERE name='%q' AND type='index'"
      "UNION ALL "
      "SELECT rootpage, 1 FROM sqlite_schema"
      " WHERE name='%q' AND type='table'"
      "   AND sql LIKE '%%without%%rowid%%'",
      azArg[1], azArg[1]
    );
    sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    if( sqlite3_step(pStmt)==SQLITE_ROW ){

      }else{
        raw_printf(stderr, "Usage: .schema ?--indent? ?LIKE-PATTERN?\n");
        rc = 1;
        goto meta_command_exit;
      }
    }
    if( zName!=0 ){
      int isSchema = sqlite3_strlike(zName, "sqlite_master", '\\')==0
                  || sqlite3_strlike(zName, "sqlite_schema", '\\')==0
                  || sqlite3_strlike(zName,"sqlite_temp_master", '\\')==0
                  || sqlite3_strlike(zName,"sqlite_temp_schema", '\\')==0;
      if( isSchema ){
        char *new_argv[2], *new_colv[2];
        new_argv[0] = sqlite3_mprintf(
                      "CREATE TABLE %s (\n"
                      "  type text,\n"
                      "  name text,\n"
                      "  tbl_name text,\n"
                      "  rootpage integer,\n"
                      "  sql text\n"
                      ")", zName);
        new_argv[1] = 0;
        new_colv[0] = "sql";
        new_colv[1] = 0;
        callback(&data, 1, new_argv, new_colv);
        sqlite3_free(new_argv[0]);
      }
    }

        }
        appendText(&sSelect, ",name) AS sql, type, tbl_name, name, rowid,", 0);
        appendText(&sSelect, zScNum, 0);
        appendText(&sSelect, " AS snum, ", 0);
        appendText(&sSelect, zDb, '\'');
        appendText(&sSelect, " AS sname FROM ", 0);
        appendText(&sSelect, zDb, quoteChar(zDb));
        appendText(&sSelect, ".sqlite_schema", 0);
      }
      sqlite3_finalize(pStmt);
#ifndef SQLITE_OMIT_INTROSPECTION_PRAGMAS
      if( zName ){
        appendText(&sSelect,
           " UNION ALL SELECT shell_module_schema(name),"
           " 'table', name, name, name, 9e+99, 'main' FROM pragma_module_list",

      }else{
        zLike = z;
        bSeparate = 1;
        if( sqlite3_strlike("sqlite\\_%", zLike, '\\')==0 ) bSchema = 1;
      }
    }
    if( bSchema ){
      zSql = "SELECT lower(name) FROM sqlite_schema"
             " WHERE type='table' AND coalesce(rootpage,0)>1"
             " UNION ALL SELECT 'sqlite_schema'"
             " ORDER BY 1 collate nocase";
    }else{
      zSql = "SELECT lower(name) FROM sqlite_schema"
             " WHERE type='table' AND coalesce(rootpage,0)>1"
             " AND name NOT LIKE 'sqlite_%'"
             " ORDER BY 1 collate nocase";
    }
    sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    initText(&sQuery);
    initText(&sSql);
    appendText(&sSql, "WITH [sha3sum$query](a,b) AS(",0);
    zSep = "VALUES(";
    while( SQLITE_ROW==sqlite3_step(pStmt) ){
      const char *zTab = (const char*)sqlite3_column_text(pStmt,0);
      if( zLike && sqlite3_strlike(zLike, zTab, 0)!=0 ) continue;
      if( strncmp(zTab, "sqlite_",7)!=0 ){
        appendText(&sQuery,"SELECT * FROM ", 0);
        appendText(&sQuery,zTab,'"');
        appendText(&sQuery," NOT INDEXED;", 0);
      }else if( strcmp(zTab, "sqlite_schema")==0 ){
        appendText(&sQuery,"SELECT type,name,tbl_name,sql FROM sqlite_schema"
                           " ORDER BY name;", 0);
      }else if( strcmp(zTab, "sqlite_sequence")==0 ){
        appendText(&sQuery,"SELECT name,seq FROM sqlite_sequence"
                           " ORDER BY name;", 0);
      }else if( strcmp(zTab, "sqlite_stat1")==0 ){
        appendText(&sQuery,"SELECT tbl,idx,stat FROM sqlite_stat1"
                           " ORDER BY tbl,idx;", 0);

        appendText(&s, "SELECT name FROM ", 0);
      }else{
        appendText(&s, "SELECT ", 0);
        appendText(&s, zDbName, '\'');
        appendText(&s, "||'.'||name FROM ", 0);
      }
      appendText(&s, zDbName, '"');
      appendText(&s, ".sqlite_schema ", 0);
      if( c=='t' ){
        appendText(&s," WHERE type IN ('table','view')"
                      "   AND name NOT LIKE 'sqlite_%'"
                      "   AND name LIKE ?1", 0);
      }else{
        appendText(&s," WHERE type='index'"
                      "   AND tbl_name LIKE ?1", 0);

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.33.0"
#define SQLITE_VERSION_NUMBER 3033000
#define SQLITE_SOURCE_ID      "2020-06-19 15:24:12 7a876209a678a34c198b54ceef9e3c041f128a14dc73357f6a57cadadaa6cf7b"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

#define SQLITE_OPEN_MEMORY           0x00000080  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
#define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
#define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
#define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
#define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
#define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
#define SQLITE_OPEN_SUPER_JOURNAL    0x00004000  /* VFS only */
#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
#define SQLITE_OPEN_NOFOLLOW         0x01000000  /* Ok for sqlite3_open_v2() */

/* Reserved:                         0x00F00000 */
/* Legacy compatibility: */
#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */


/*
** CAPI3REF: Device Characteristics
**
** The xDeviceCharacteristics method of the [sqlite3_io_methods]
** object returns an integer which is a vector of these
** bit values expressing I/O characteristics of the mass storage

** sent to the VFS immediately before the xSync method is invoked on a
** database file descriptor. Or, if the xSync method is not invoked 
** because the user has configured SQLite with 
** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 
** of the xSync method. In most cases, the pointer argument passed with
** this file-control is NULL. However, if the database file is being synced
** as part of a multi-database commit, the argument points to a nul-terminated
** string containing the transactions super-journal file name. VFSes that 
** do not need this signal should silently ignore this opcode. Applications 
** should not call [sqlite3_file_control()] with this opcode as doing so may 
** disrupt the operation of the specialized VFSes that do require it.  
**
** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
** and sent to the VFS after a transaction has been committed immediately

** <ul>
** <li>  [SQLITE_OPEN_MAIN_DB]
** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
** <li>  [SQLITE_OPEN_TEMP_DB]
** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
** <li>  [SQLITE_OPEN_TRANSIENT_DB]
** <li>  [SQLITE_OPEN_SUBJOURNAL]
** <li>  [SQLITE_OPEN_SUPER_JOURNAL]
** <li>  [SQLITE_OPEN_WAL]
** </ul>)^
**
** The file I/O implementation can use the object type flags to
** change the way it deals with files.  For example, an application
** that does not care about crash recovery or rollback might make
** the open of a journal file a no-op.  Writes to this journal would

** The xInit method initializes the memory allocator.  For example,
** it might allocate any required mutexes or initialize internal data
** structures.  The xShutdown method is invoked (indirectly) by
** [sqlite3_shutdown()] and should deallocate any resources acquired
** by xInit.  The pAppData pointer is used as the only parameter to
** xInit and xShutdown.
**
** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
** the xInit method, so the xInit method need not be threadsafe.  The
** xShutdown method is only called from [sqlite3_shutdown()] so it does
** not need to be threadsafe either.  For all other methods, SQLite
** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
** it is by default) and so the methods are automatically serialized.
** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other

** default value of this setting is determined by the [-DSQLITE_DQS]
** compile-time option.
** </dd>
**
** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td>
** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to

** assume that database schemas are untainted by malicious content.
** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
** takes additional defensive steps to protect the application from harm
** including:
** <ul>
** <li> Prohibit the use of SQL functions inside triggers, views,
** CHECK constraints, DEFAULT clauses, expression indexes, 
** partial indexes, or generated columns

** to be invoked.
** ^The third and fourth arguments to the callback contain pointers to the
** database and table name containing the affected row.
** ^The final callback parameter is the [rowid] of the row.
** ^In the case of an update, this is the [rowid] after the update takes place.
**
** ^(The update hook is not invoked when internal system tables are
** modified (i.e. sqlite_sequence).)^
** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
**
** ^In the current implementation, the update hook
** is not invoked when conflicting rows are deleted because of an
** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
** invoked when rows are deleted using the [truncate optimization].
** The exceptions defined in this paragraph might change in a future

** routine returns NULL if it is unable to allocate the requested
** mutex.  The argument to sqlite3_mutex_alloc() must one of these
** integer constants:
**
** <ul>
** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MAIN
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_OPEN
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_PMEM
** <li>  SQLITE_MUTEX_STATIC_APP1
** <li>  SQLITE_MUTEX_STATIC_APP2

**
** The set of static mutexes may change from one SQLite release to the
** next.  Applications that override the built-in mutex logic must be
** prepared to accommodate additional static mutexes.
*/
#define SQLITE_MUTEX_FAST             0
#define SQLITE_MUTEX_RECURSIVE        1
#define SQLITE_MUTEX_STATIC_MAIN      2
#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
#define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
#define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_randomness() */
#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
#define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
#define SQLITE_MUTEX_STATIC_APP1      8  /* For use by application */
#define SQLITE_MUTEX_STATIC_APP2      9  /* For use by application */
#define SQLITE_MUTEX_STATIC_APP3     10  /* For use by application */
#define SQLITE_MUTEX_STATIC_VFS1     11  /* For use by built-in VFS */
#define SQLITE_MUTEX_STATIC_VFS2     12  /* For use by extension VFS */
#define SQLITE_MUTEX_STATIC_VFS3     13  /* For use by application VFS */

/* Legacy compatibility: */
#define SQLITE_MUTEX_STATIC_MASTER    2


/*
** CAPI3REF: Retrieve the mutex for a database connection
** METHOD: sqlite3
**
** ^This interface returns a pointer the [sqlite3_mutex] object that 
** serializes access to the [database connection] given in the argument

** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
** with a NULL pointer as the second parameter.
** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
** the first parameter to callbacks.
**
** ^The preupdate hook only fires for changes to real database tables; the
** preupdate hook is not invoked for changes to [virtual tables] or to
** system tables like sqlite_sequence or sqlite_stat1.
**
** ^The second parameter to the preupdate callback is a pointer to
** the [database connection] that registered the preupdate hook.
** ^The third parameter to the preupdate callback is one of the constants
** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
** kind of update operation that is about to occur.
** ^(The fourth parameter to the preupdate callback is the name of the

** the Select query generator tracing logic is turned on.
*/
#if defined(SQLITE_ENABLE_SELECTTRACE)
# define SELECTTRACE_ENABLED 1
#else
# define SELECTTRACE_ENABLED 0
#endif
#if defined(SQLITE_ENABLE_SELECTTRACE)
# define SELECTTRACE_ENABLED 1
# define SELECTTRACE(K,P,S,X)  \
  if(sqlite3SelectTrace&(K))   \
    sqlite3DebugPrintf("%u/%d/%p: ",(S)->selId,(P)->addrExplain,(S)),\
    sqlite3DebugPrintf X
#else
# define SELECTTRACE(K,P,S,X)
# define SELECTTRACE_ENABLED 0
#endif

/*
** An instance of the following structure is used to store the busy-handler
** callback for a given sqlite handle.
**
** The sqlite.busyHandler member of the sqlite struct contains the busy
** callback for the database handle. Each pager opened via the sqlite
** handle is passed a pointer to sqlite.busyHandler. The busy-handler
** callback is currently invoked only from within pager.c.
*/
typedef struct BusyHandler BusyHandler;
struct BusyHandler {
  int (*xBusyHandler)(void *,int);  /* The busy callback */
  void *pBusyArg;                   /* First arg to busy callback */
  int nBusy;                        /* Incremented with each busy call */
};

/*

** Name of table that holds the database schema.

*/
#define DFLT_SCHEMA_TABLE          "sqlite_master"
#define DFLT_TEMP_SCHEMA_TABLE     "sqlite_temp_master"
#define ALT_SCHEMA_TABLE           "sqlite_schema"
#define ALT_TEMP_SCHEMA_TABLE      "sqlite_temp_schema"


/*
** The root-page of the schema table.
*/
#define SCHEMA_ROOT    1

/*
** The name of the schema table.  The name is different for TEMP.
*/
#define SCHEMA_TABLE(x) \
    ((!OMIT_TEMPDB)&&(x==1)?DFLT_TEMP_SCHEMA_TABLE:DFLT_SCHEMA_TABLE)

/*
** A convenience macro that returns the number of elements in
** an array.
*/
#define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))

SQLITE_PRIVATE u32 sqlite3BtreeLastPage(Btree*);
SQLITE_PRIVATE int sqlite3BtreeSecureDelete(Btree*,int);
SQLITE_PRIVATE int sqlite3BtreeGetRequestedReserve(Btree*);
SQLITE_PRIVATE int sqlite3BtreeGetReserveNoMutex(Btree *p);
SQLITE_PRIVATE int sqlite3BtreeSetAutoVacuum(Btree *, int);
SQLITE_PRIVATE int sqlite3BtreeGetAutoVacuum(Btree *);
SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree*,int,int*);
SQLITE_PRIVATE int sqlite3BtreeCommitPhaseOne(Btree*, const char*);
SQLITE_PRIVATE int sqlite3BtreeCommitPhaseTwo(Btree*, int);
SQLITE_PRIVATE int sqlite3BtreeCommit(Btree*);
SQLITE_PRIVATE int sqlite3BtreeRollback(Btree*,int,int);
SQLITE_PRIVATE int sqlite3BtreeBeginStmt(Btree*,int);
SQLITE_PRIVATE int sqlite3BtreeCreateTable(Btree*, int*, int flags);
SQLITE_PRIVATE int sqlite3BtreeIsInTrans(Btree*);
SQLITE_PRIVATE int sqlite3BtreeIsInReadTrans(Btree*);

*/
typedef struct PgHdr DbPage;

/*
** Page number PAGER_MJ_PGNO is never used in an SQLite database (it is
** reserved for working around a windows/posix incompatibility). It is
** used in the journal to signify that the remainder of the journal file 
** is devoted to storing a super-journal name - there are no more pages to
** roll back. See comments for function writeSuperJournal() in pager.c 
** for details.
*/
#define PAGER_MJ_PGNO(x) ((Pgno)((PENDING_BYTE/((x)->pageSize))+1))

/*
** Allowed values for the flags parameter to sqlite3PagerOpen().
**

SQLITE_PRIVATE int sqlite3PagerPageRefcount(DbPage*);
SQLITE_PRIVATE void *sqlite3PagerGetData(DbPage *); 
SQLITE_PRIVATE void *sqlite3PagerGetExtra(DbPage *); 

/* Functions used to manage pager transactions and savepoints. */
SQLITE_PRIVATE void sqlite3PagerPagecount(Pager*, int*);
SQLITE_PRIVATE int sqlite3PagerBegin(Pager*, int exFlag, int);
SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(Pager*,const char *zSuper, int);
SQLITE_PRIVATE int sqlite3PagerExclusiveLock(Pager*);
SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager, const char *zSuper);
SQLITE_PRIVATE int sqlite3PagerCommitPhaseTwo(Pager*);
SQLITE_PRIVATE int sqlite3PagerRollback(Pager*);
SQLITE_PRIVATE int sqlite3PagerOpenSavepoint(Pager *pPager, int n);
SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint);
SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager);

#ifndef SQLITE_OMIT_WAL

  int busyTimeout;              /* Busy handler timeout, in msec */
  int nSavepoint;               /* Number of non-transaction savepoints */
  int nStatement;               /* Number of nested statement-transactions  */
  i64 nDeferredCons;            /* Net deferred constraints this transaction. */
  i64 nDeferredImmCons;         /* Net deferred immediate constraints */
  int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
  /* The following variables are all protected by the STATIC_MAIN
  ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
  **
  ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
  ** unlock so that it can proceed.
  **
  ** When X.pBlockingConnection==Y, that means that something that X tried
  ** tried to do recently failed with an SQLITE_LOCKED error due to locks

** Possible values for the sqlite3.flags.
**
** Value constraints (enforced via assert()):
**      SQLITE_FullFSync     == PAGER_FULLFSYNC
**      SQLITE_CkptFullFSync == PAGER_CKPT_FULLFSYNC
**      SQLITE_CacheSpill    == PAGER_CACHE_SPILL
*/
#define SQLITE_WriteSchema    0x00000001  /* OK to update SQLITE_SCHEMA */
#define SQLITE_LegacyFileFmt  0x00000002  /* Create new databases in format 1 */
#define SQLITE_FullColNames   0x00000004  /* Show full column names on SELECT */
#define SQLITE_FullFSync      0x00000008  /* Use full fsync on the backend */
#define SQLITE_CkptFullFSync  0x00000010  /* Use full fsync for checkpoint */
#define SQLITE_CacheSpill     0x00000020  /* OK to spill pager cache */
#define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
#define SQLITE_TrustedSchema  0x00000080  /* Allow unsafe functions and

** must be unique and what to do if they are not.  When Index.onError=OE_None,
** it means this is not a unique index.  Otherwise it is a unique index
** and the value of Index.onError indicate the which conflict resolution
** algorithm to employ whenever an attempt is made to insert a non-unique
** element.
**
** While parsing a CREATE TABLE or CREATE INDEX statement in order to
** generate VDBE code (as opposed to parsing one read from an sqlite_schema
** table as part of parsing an existing database schema), transient instances
** of this structure may be created. In this case the Index.tnum variable is
** used to store the address of a VDBE instruction, not a database page
** number (it cannot - the database page is not allocated until the VDBE
** program is executed). See convertToWithoutRowidTable() for details.
*/
struct Index {

  int sortingIdx;         /* Cursor number of the sorting index */
  int sortingIdxPTab;     /* Cursor number of pseudo-table */
  int nSortingColumn;     /* Number of columns in the sorting index */
  int mnReg, mxReg;       /* Range of registers allocated for aCol and aFunc */
  ExprList *pGroupBy;     /* The group by clause */
  struct AggInfo_col {    /* For each column used in source tables */
    Table *pTab;             /* Source table */
    Expr *pCExpr;            /* The original expression */
    int iTable;              /* Cursor number of the source table */
    int iMem;                /* Memory location that acts as accumulator */
    i16 iColumn;             /* Column number within the source table */
    i16 iSorterColumn;       /* Column number in the sorting index */
  } *aCol;
  int nColumn;            /* Number of used entries in aCol[] */
  int nAccumulator;       /* Number of columns that show through to the output.
                          ** Additional columns are used only as parameters to
                          ** aggregate functions */
  struct AggInfo_func {   /* For each aggregate function */
    Expr *pFExpr;            /* Expression encoding the function */
    FuncDef *pFunc;          /* The aggregate function implementation */
    int iMem;                /* Memory location that acts as accumulator */
    int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
  } *aFunc;
  int nFunc;              /* Number of entries in aFunc[] */

  u32 selId;              /* Select to which this AggInfo belongs */

  AggInfo *pNext;         /* Next in list of them all */
};

/*
** Value for AggInfo.iAggMagic when the structure is valid
*/
#define AggInfoMagic  0x2059e99e

#define EP_Leaf       0x800000 /* Expr.pLeft, .pRight, .u.pSelect all NULL */
#define EP_WinFunc   0x1000000 /* TK_FUNCTION with Expr.y.pWin set */
#define EP_Subrtn    0x2000000 /* Uses Expr.y.sub. TK_IN, _SELECT, or _EXISTS */
#define EP_Quoted    0x4000000 /* TK_ID was originally quoted */
#define EP_Static    0x8000000 /* Held in memory not obtained from malloc() */
#define EP_IsTrue   0x10000000 /* Always has boolean value of TRUE */
#define EP_IsFalse  0x20000000 /* Always has boolean value of FALSE */
#define EP_FromDDL  0x40000000 /* Originates from sqlite_schema */
               /*   0x80000000 // Available */

/*
** The EP_Propagate mask is a set of properties that automatically propagate
** upwards into parent nodes.
*/
#define EP_Propagate (EP_Collate|EP_Subquery|EP_HasFunc)

      u8 jointype;      /* Type of join between this table and the previous */
      unsigned notIndexed :1;    /* True if there is a NOT INDEXED clause */
      unsigned isIndexedBy :1;   /* True if there is an INDEXED BY clause */
      unsigned isTabFunc :1;     /* True if table-valued-function syntax */
      unsigned isCorrelated :1;  /* True if sub-query is correlated */
      unsigned viaCoroutine :1;  /* Implemented as a co-routine */
      unsigned isRecursive :1;   /* True for recursive reference in WITH */
      unsigned fromDDL :1;       /* Comes from sqlite_schema */
    } fg;
    int iCursor;      /* The VDBE cursor number used to access this table */
    Expr *pOn;        /* The ON clause of a join */
    IdList *pUsing;   /* The USING clause of a join */
    Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
    union {
      char *zIndexedBy;    /* Identifier from "INDEXED BY <zIndex>" clause */

#define NC_UUpsert   0x00200  /* True if uNC.pUpsert is used */
#define NC_MinMaxAgg 0x01000  /* min/max aggregates seen.  See note above */
#define NC_Complex   0x02000  /* True if a function or subquery seen */
#define NC_AllowWin  0x04000  /* Window functions are allowed here */
#define NC_HasWin    0x08000  /* One or more window functions seen */
#define NC_IsDDL     0x10000  /* Resolving names in a CREATE statement */
#define NC_InAggFunc 0x20000  /* True if analyzing arguments to an agg func */
#define NC_FromDDL   0x40000  /* SQL text comes from sqlite_schema */

/*
** An instance of the following object describes a single ON CONFLICT
** clause in an upsert.
**
** The pUpsertTarget field is only set if the ON CONFLICT clause includes
** conflict-target clause.  (In "ON CONFLICT(a,b)" the "(a,b)" is the

#define SF_MaybeConvert  0x0008000 /* Need convertCompoundSelectToSubquery() */
#define SF_Converted     0x0010000 /* By convertCompoundSelectToSubquery() */
#define SF_IncludeHidden 0x0020000 /* Include hidden columns in output */
#define SF_ComplexResult 0x0040000 /* Result contains subquery or function */
#define SF_WhereBegin    0x0080000 /* Really a WhereBegin() call.  Debug Only */
#define SF_WinRewrite    0x0100000 /* Window function rewrite accomplished */
#define SF_View          0x0200000 /* SELECT statement is a view */
#define SF_NoopOrderBy   0x0400000 /* ORDER BY is ignored for this query */

/*
** The results of a SELECT can be distributed in several ways, as defined
** by one of the following macros.  The "SRT" prefix means "SELECT Result
** Type".
**
**     SRT_Union       Store results as a key in a temporary index

SQLITE_PRIVATE void sqlite3ResetOneSchema(sqlite3*,int);
SQLITE_PRIVATE void sqlite3CollapseDatabaseArray(sqlite3*);
SQLITE_PRIVATE void sqlite3CommitInternalChanges(sqlite3*);
SQLITE_PRIVATE void sqlite3DeleteColumnNames(sqlite3*,Table*);
SQLITE_PRIVATE int sqlite3ColumnsFromExprList(Parse*,ExprList*,i16*,Column**);
SQLITE_PRIVATE void sqlite3SelectAddColumnTypeAndCollation(Parse*,Table*,Select*,char);
SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse*,Select*,char);
SQLITE_PRIVATE void sqlite3OpenSchemaTable(Parse *, int);
SQLITE_PRIVATE Index *sqlite3PrimaryKeyIndex(Table*);
SQLITE_PRIVATE i16 sqlite3TableColumnToIndex(Index*, i16);
#ifdef SQLITE_OMIT_GENERATED_COLUMNS
# define sqlite3TableColumnToStorage(T,X) (X)  /* No-op pass-through */
# define sqlite3StorageColumnToTable(T,X) (X)  /* No-op pass-through */
#else
SQLITE_PRIVATE   i16 sqlite3TableColumnToStorage(Table*, i16);

#ifndef SQLITE_AMALGAMATION
SQLITE_PRIVATE const unsigned char sqlite3OpcodeProperty[];
SQLITE_PRIVATE const char sqlite3StrBINARY[];
SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[];
SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[];
SQLITE_PRIVATE SQLITE_WSD struct Sqlite3Config sqlite3Config;
SQLITE_PRIVATE FuncDefHash sqlite3BuiltinFunctions;
SQLITE_PRIVATE u32 sqlite3SelectTrace;
#ifndef SQLITE_OMIT_WSD
SQLITE_PRIVATE int sqlite3PendingByte;
#endif
#endif /* SQLITE_AMALGAMATION */
#ifdef VDBE_PROFILE
SQLITE_PRIVATE sqlite3_uint64 sqlite3NProfileCnt;
#endif
SQLITE_PRIVATE void sqlite3RootPageMoved(sqlite3*, int, int, int);
SQLITE_PRIVATE void sqlite3Reindex(Parse*, Token*, Token*);
SQLITE_PRIVATE void sqlite3AlterFunctions(void);
SQLITE_PRIVATE void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);

** Changing the pending byte during operation will result in undefined
** and incorrect behavior.
*/
#ifndef SQLITE_OMIT_WSD
SQLITE_PRIVATE int sqlite3PendingByte = 0x40000000;
#endif

/*
** Flags for select tracing and the ".selecttrace" macro of the CLI
*/
/**/ u32 sqlite3SelectTrace = 0;

/* #include "opcodes.h" */
/*
** Properties of opcodes.  The OPFLG_INITIALIZER macro is
** created by mkopcodeh.awk during compilation.  Data is obtained
** from the comments following the "case OP_xxxx:" statements in
** the vdbe.c file.  
*/

** local time.
*/
static int osLocaltime(time_t *t, struct tm *pTm){
  int rc;
#if !HAVE_LOCALTIME_R && !HAVE_LOCALTIME_S
  struct tm *pX;
#if SQLITE_THREADSAFE>0
  sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
#endif
  sqlite3_mutex_enter(mutex);
  pX = localtime(t);
#ifndef SQLITE_UNTESTABLE
  if( sqlite3GlobalConfig.bLocaltimeFault ) pX = 0;
#endif
  if( pX ) *pTm = *pX;

  iT = sqlite3StmtCurrentTime(context);
  if( iT<=0 ) return;
  t = iT/1000 - 10000*(sqlite3_int64)21086676;
#if HAVE_GMTIME_R
  pTm = gmtime_r(&t, &sNow);
#else
  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN));
  pTm = gmtime(&t);
  if( pTm ) memcpy(&sNow, pTm, sizeof(sNow));
  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN));
#endif
  if( pTm ){
    strftime(zBuf, 20, zFormat, &sNow);
    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
  }
}
#endif

  sqlite3_mutex *mutex;
#endif
#ifndef SQLITE_OMIT_AUTOINIT
  int rc = sqlite3_initialize();
  if( rc ) return 0;
#endif
#if SQLITE_THREADSAFE
  mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
#endif
  sqlite3_mutex_enter(mutex);
  for(pVfs = vfsList; pVfs; pVfs=pVfs->pNext){
    if( zVfs==0 ) break;
    if( strcmp(zVfs, pVfs->zName)==0 ) break;
  }
  sqlite3_mutex_leave(mutex);
  return pVfs;
}

/*
** Unlink a VFS from the linked list
*/
static void vfsUnlink(sqlite3_vfs *pVfs){
  assert( sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN)) );
  if( pVfs==0 ){
    /* No-op */
  }else if( vfsList==pVfs ){
    vfsList = pVfs->pNext;
  }else if( vfsList ){
    sqlite3_vfs *p = vfsList;
    while( p->pNext && p->pNext!=pVfs ){

  int rc = sqlite3_initialize();
  if( rc ) return rc;
#endif
#ifdef SQLITE_ENABLE_API_ARMOR
  if( pVfs==0 ) return SQLITE_MISUSE_BKPT;
#endif

  MUTEX_LOGIC( mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN); )
  sqlite3_mutex_enter(mutex);
  vfsUnlink(pVfs);
  if( makeDflt || vfsList==0 ){
    pVfs->pNext = vfsList;
    vfsList = pVfs;
  }else{
    pVfs->pNext = vfsList->pNext;

*/
SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs *pVfs){
  MUTEX_LOGIC(sqlite3_mutex *mutex;)
#ifndef SQLITE_OMIT_AUTOINIT
  int rc = sqlite3_initialize();
  if( rc ) return rc;
#endif
  MUTEX_LOGIC( mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN); )
  sqlite3_mutex_enter(mutex);
  vfsUnlink(pVfs);
  sqlite3_mutex_leave(mutex);
  return SQLITE_OK;
}

/************** End of os.c **************************************************/

  ** Mutex to control access to the memory allocation subsystem.
  */
  sqlite3_mutex *mutex;
  
  /*
  ** The minimum amount of free space that we have seen.
  */
  u32 mnKeyBlk;

  /*
  ** iKeyBlk is the index of the key chunk.  Most new allocations
  ** occur off of this chunk.  szKeyBlk is the size (in Mem3Blocks)
  ** of the current key chunk.  iKeyBlk is 0 if there is no key chunk.
  ** The key chunk is not in either the aiHash[] or aiSmall[].
  */
  u32 iKeyBlk;
  u32 szKeyBlk;

  /*
  ** Array of lists of free blocks according to the block size 
  ** for smaller chunks, or a hash on the block size for larger
  ** chunks.
  */
  u32 aiSmall[MX_SMALL-1];   /* For sizes 2 through MX_SMALL, inclusive */

  mem3.aPool[i-1].u.hdr.size4x = nBlock*4 | 1 | (x&2);
  mem3.aPool[i+nBlock-1].u.hdr.prevSize = nBlock;
  mem3.aPool[i+nBlock-1].u.hdr.size4x |= 2;
  return &mem3.aPool[i];
}

/*
** Carve a piece off of the end of the mem3.iKeyBlk free chunk.
** Return a pointer to the new allocation.  Or, if the key chunk
** is not large enough, return 0.
*/
static void *memsys3FromKeyBlk(u32 nBlock){
  assert( sqlite3_mutex_held(mem3.mutex) );
  assert( mem3.szKeyBlk>=nBlock );
  if( nBlock>=mem3.szKeyBlk-1 ){
    /* Use the entire key chunk */
    void *p = memsys3Checkout(mem3.iKeyBlk, mem3.szKeyBlk);
    mem3.iKeyBlk = 0;
    mem3.szKeyBlk = 0;
    mem3.mnKeyBlk = 0;
    return p;
  }else{
    /* Split the key block.  Return the tail. */
    u32 newi, x;
    newi = mem3.iKeyBlk + mem3.szKeyBlk - nBlock;
    assert( newi > mem3.iKeyBlk+1 );
    mem3.aPool[mem3.iKeyBlk+mem3.szKeyBlk-1].u.hdr.prevSize = nBlock;
    mem3.aPool[mem3.iKeyBlk+mem3.szKeyBlk-1].u.hdr.size4x |= 2;
    mem3.aPool[newi-1].u.hdr.size4x = nBlock*4 + 1;
    mem3.szKeyBlk -= nBlock;
    mem3.aPool[newi-1].u.hdr.prevSize = mem3.szKeyBlk;
    x = mem3.aPool[mem3.iKeyBlk-1].u.hdr.size4x & 2;
    mem3.aPool[mem3.iKeyBlk-1].u.hdr.size4x = mem3.szKeyBlk*4 | x;
    if( mem3.szKeyBlk < mem3.mnKeyBlk ){
      mem3.mnKeyBlk = mem3.szKeyBlk;
    }
    return (void*)&mem3.aPool[newi];
  }
}

/*
** *pRoot is the head of a list of free chunks of the same size
** or same size hash.  In other words, *pRoot is an entry in either
** mem3.aiSmall[] or mem3.aiHash[].  
**
** This routine examines all entries on the given list and tries
** to coalesce each entries with adjacent free chunks.  
**
** If it sees a chunk that is larger than mem3.iKeyBlk, it replaces 
** the current mem3.iKeyBlk with the new larger chunk.  In order for
** this mem3.iKeyBlk replacement to work, the key chunk must be
** linked into the hash tables.  That is not the normal state of
** affairs, of course.  The calling routine must link the key
** chunk before invoking this routine, then must unlink the (possibly
** changed) key chunk once this routine has finished.
*/
static void memsys3Merge(u32 *pRoot){
  u32 iNext, prev, size, i, x;

  assert( sqlite3_mutex_held(mem3.mutex) );
  for(i=*pRoot; i>0; i=iNext){
    iNext = mem3.aPool[i].u.list.next;

      mem3.aPool[prev-1].u.hdr.size4x = size*4 | x;
      mem3.aPool[prev+size-1].u.hdr.prevSize = size;
      memsys3Link(prev);
      i = prev;
    }else{
      size /= 4;
    }
    if( size>mem3.szKeyBlk ){
      mem3.iKeyBlk = i;
      mem3.szKeyBlk = size;
    }
  }
}

/*
** Return a block of memory of at least nBytes in size.
** Return NULL if unable.

        return memsys3Checkout(i, nBlock);
      }
    }
  }

  /* STEP 2:
  ** Try to satisfy the allocation by carving a piece off of the end
  ** of the key chunk.  This step usually works if step 1 fails.
  */
  if( mem3.szKeyBlk>=nBlock ){
    return memsys3FromKeyBlk(nBlock);
  }


  /* STEP 3:  
  ** Loop through the entire memory pool.  Coalesce adjacent free
  ** chunks.  Recompute the key chunk as the largest free chunk.
  ** Then try again to satisfy the allocation by carving a piece off
  ** of the end of the key chunk.  This step happens very
  ** rarely (we hope!)
  */
  for(toFree=nBlock*16; toFree<(mem3.nPool*16); toFree *= 2){
    memsys3OutOfMemory(toFree);
    if( mem3.iKeyBlk ){
      memsys3Link(mem3.iKeyBlk);
      mem3.iKeyBlk = 0;
      mem3.szKeyBlk = 0;
    }
    for(i=0; i<N_HASH; i++){
      memsys3Merge(&mem3.aiHash[i]);
    }
    for(i=0; i<MX_SMALL-1; i++){
      memsys3Merge(&mem3.aiSmall[i]);
    }
    if( mem3.szKeyBlk ){
      memsys3Unlink(mem3.iKeyBlk);
      if( mem3.szKeyBlk>=nBlock ){
        return memsys3FromKeyBlk(nBlock);
      }
    }
  }

  /* If none of the above worked, then we fail. */
  return 0;
}

  size = mem3.aPool[i-1].u.hdr.size4x/4;
  assert( i+size<=mem3.nPool+1 );
  mem3.aPool[i-1].u.hdr.size4x &= ~1;
  mem3.aPool[i+size-1].u.hdr.prevSize = size;
  mem3.aPool[i+size-1].u.hdr.size4x &= ~2;
  memsys3Link(i);

  /* Try to expand the key using the newly freed chunk */
  if( mem3.iKeyBlk ){
    while( (mem3.aPool[mem3.iKeyBlk-1].u.hdr.size4x&2)==0 ){
      size = mem3.aPool[mem3.iKeyBlk-1].u.hdr.prevSize;
      mem3.iKeyBlk -= size;
      mem3.szKeyBlk += size;
      memsys3Unlink(mem3.iKeyBlk);
      x = mem3.aPool[mem3.iKeyBlk-1].u.hdr.size4x & 2;
      mem3.aPool[mem3.iKeyBlk-1].u.hdr.size4x = mem3.szKeyBlk*4 | x;
      mem3.aPool[mem3.iKeyBlk+mem3.szKeyBlk-1].u.hdr.prevSize = mem3.szKeyBlk;
    }
    x = mem3.aPool[mem3.iKeyBlk-1].u.hdr.size4x & 2;
    while( (mem3.aPool[mem3.iKeyBlk+mem3.szKeyBlk-1].u.hdr.size4x&1)==0 ){
      memsys3Unlink(mem3.iKeyBlk+mem3.szKeyBlk);
      mem3.szKeyBlk += mem3.aPool[mem3.iKeyBlk+mem3.szKeyBlk-1].u.hdr.size4x/4;
      mem3.aPool[mem3.iKeyBlk-1].u.hdr.size4x = mem3.szKeyBlk*4 | x;
      mem3.aPool[mem3.iKeyBlk+mem3.szKeyBlk-1].u.hdr.prevSize = mem3.szKeyBlk;
    }
  }
}

/*
** Return the size of an outstanding allocation, in bytes.  The
** size returned omits the 8-byte header overhead.  This only

  }

  /* Store a pointer to the memory block in global structure mem3. */
  assert( sizeof(Mem3Block)==8 );
  mem3.aPool = (Mem3Block *)sqlite3GlobalConfig.pHeap;
  mem3.nPool = (sqlite3GlobalConfig.nHeap / sizeof(Mem3Block)) - 2;

  /* Initialize the key block. */
  mem3.szKeyBlk = mem3.nPool;
  mem3.mnKeyBlk = mem3.szKeyBlk;
  mem3.iKeyBlk = 1;
  mem3.aPool[0].u.hdr.size4x = (mem3.szKeyBlk<<2) + 2;
  mem3.aPool[mem3.nPool].u.hdr.prevSize = mem3.nPool;
  mem3.aPool[mem3.nPool].u.hdr.size4x = 1;

  return SQLITE_OK;
}

/*

      assert( 0 );
      break;
    }
    if( size&1 ){
      fprintf(out, "%p %6d bytes checked out\n", &mem3.aPool[i], (size/4)*8-8);
    }else{
      fprintf(out, "%p %6d bytes free%s\n", &mem3.aPool[i], (size/4)*8-8,
                  i==mem3.iKeyBlk ? " **key**" : "");
    }
  }
  for(i=0; i<MX_SMALL-1; i++){
    if( mem3.aiSmall[i]==0 ) continue;
    fprintf(out, "small(%2d):", i);
    for(j = mem3.aiSmall[i]; j>0; j=mem3.aPool[j].u.list.next){
      fprintf(out, " %p(%d)", &mem3.aPool[j],
              (mem3.aPool[j-1].u.hdr.size4x/4)*8-8);
    }
    fprintf(out, "\n"); 
  }
  for(i=0; i<N_HASH; i++){
    if( mem3.aiHash[i]==0 ) continue;
    fprintf(out, "hash(%2d):", i);
    for(j = mem3.aiHash[i]; j>0; j=mem3.aPool[j].u.list.next){
      fprintf(out, " %p(%d)", &mem3.aPool[j],
              (mem3.aPool[j-1].u.hdr.size4x/4)*8-8);
    }
    fprintf(out, "\n"); 
  }
  fprintf(out, "key=%d\n", mem3.iKeyBlk);
  fprintf(out, "nowUsed=%d\n", mem3.nPool*8 - mem3.szKeyBlk*8);
  fprintf(out, "mxUsed=%d\n", mem3.nPool*8 - mem3.mnKeyBlk*8);
  sqlite3_mutex_leave(mem3.mutex);
  if( out==stdout ){
    fflush(stdout);
  }else{
    fclose(out);
  }
#else

** that means that a mutex could not be allocated.  SQLite
** will unwind its stack and return an error.  The argument
** to sqlite3_mutex_alloc() is one of these integer constants:
**
** <ul>
** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MAIN
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_OPEN
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_PMEM
** <li>  SQLITE_MUTEX_STATIC_APP1
** <li>  SQLITE_MUTEX_STATIC_APP2

** that means that a mutex could not be allocated.  SQLite
** will unwind its stack and return an error.  The argument
** to sqlite3_mutex_alloc() is one of these integer constants:
**
** <ul>
** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MAIN
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_OPEN
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_PMEM
** <li>  SQLITE_MUTEX_STATIC_APP1
** <li>  SQLITE_MUTEX_STATIC_APP2

#ifndef SQLITE_OMIT_WINDOWFUNC
        pWin = ExprHasProperty(pExpr, EP_WinFunc) ? pExpr->y.pWin : 0;
#else
        pWin = 0;
#endif 
      }
      if( pExpr->op==TK_AGG_FUNCTION ){
        sqlite3TreeViewLine(pView, "AGG_FUNCTION%d %Q%s agg=%d[%d]/%p",
                             pExpr->op2, pExpr->u.zToken, zFlgs,
                             pExpr->pAggInfo ? pExpr->pAggInfo->selId : 0,
                             pExpr->iAgg, pExpr->pAggInfo);
      }else if( pExpr->op2!=0 ){
        const char *zOp2;
        char zBuf[8];
        sqlite3_snprintf(sizeof(zBuf),zBuf,"0x%02x",pExpr->op2);
        zOp2 = zBuf;
        if( pExpr->op2==NC_IsCheck ) zOp2 = "NC_IsCheck";

){
  unixFile *pFile = (unixFile *)id;
  int got;
  assert( id );
  assert( offset>=0 );
  assert( amt>0 );

  /* If this is a database file (not a journal, super-journal or temp
  ** file), the bytes in the locking range should never be read or written. */
#if 0
  assert( pFile->pPreallocatedUnused==0
       || offset>=PENDING_BYTE+512
       || offset+amt<=PENDING_BYTE 
  );
#endif

  sqlite3_int64 offset 
){
  unixFile *pFile = (unixFile*)id;
  int wrote = 0;
  assert( id );
  assert( amt>0 );

  /* If this is a database file (not a journal, super-journal or temp
  ** file), the bytes in the locking range should never be read or written. */
#if 0
  assert( pFile->pPreallocatedUnused==0
       || offset>=PENDING_BYTE+512
       || offset+amt<=PENDING_BYTE 
  );
#endif

** if SQLITE_PREFER_PROXY_LOCKING is defined.
*/
static int proxyTransformUnixFile(unixFile*, const char*);
#endif

/*
** Search for an unused file descriptor that was opened on the database 
** file (not a journal or super-journal file) identified by pathname
** zPath with SQLITE_OPEN_XXX flags matching those passed as the second
** argument to this function.
**
** Such a file descriptor may exist if a database connection was closed
** but the associated file descriptor could not be closed because some
** other file descriptor open on the same file is holding a file-lock.
** Refer to comments in the unixClose() function and the lengthy comment

    ** where NN is a decimal number. The NN naming schemes are 
    ** used by the test_multiplex.c module.
    */
    nDb = sqlite3Strlen30(zPath) - 1; 
    while( zPath[nDb]!='-' ){
      /* In normal operation, the journal file name will always contain
      ** a '-' character.  However in 8+3 filename mode, or if a corrupt
      ** rollback journal specifies a super-journal with a goofy name, then
      ** the '-' might be missing. */
      if( nDb==0 || zPath[nDb]=='.' ) return SQLITE_OK;
      nDb--;
    }
    memcpy(zDb, zPath, nDb);
    zDb[nDb] = '\0';

#if SQLITE_ENABLE_LOCKING_STYLE
  int isAutoProxy  = (flags & SQLITE_OPEN_AUTOPROXY);
#endif
#if defined(__APPLE__) || SQLITE_ENABLE_LOCKING_STYLE
  struct statfs fsInfo;
#endif

  /* If creating a super- or main-file journal, this function will open
  ** a file-descriptor on the directory too. The first time unixSync()
  ** is called the directory file descriptor will be fsync()ed and close()d.
  */
  int isNewJrnl = (isCreate && (
        eType==SQLITE_OPEN_SUPER_JOURNAL 
     || eType==SQLITE_OPEN_MAIN_JOURNAL 
     || eType==SQLITE_OPEN_WAL
  ));

  /* If argument zPath is a NULL pointer, this function is required to open
  ** a temporary file. Use this buffer to store the file name in.
  */

  **   (d) if DELETEONCLOSE is set, then CREATE must also be set.
  */
  assert((isReadonly==0 || isReadWrite==0) && (isReadWrite || isReadonly));
  assert(isCreate==0 || isReadWrite);
  assert(isExclusive==0 || isCreate);
  assert(isDelete==0 || isCreate);

  /* The main DB, main journal, WAL file and super-journal are never 
  ** automatically deleted. Nor are they ever temporary files.  */
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_DB );
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_JOURNAL );
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_SUPER_JOURNAL );
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_WAL );

  /* Assert that the upper layer has set one of the "file-type" flags. */
  assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB 
       || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL 
       || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_SUPER_JOURNAL 
       || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL
  );

  /* Detect a pid change and reset the PRNG.  There is a race condition
  ** here such that two or more threads all trying to open databases at
  ** the same instant might all reset the PRNG.  But multiple resets
  ** are harmless.

      }
      goto open_finished;
    }
  }
#endif
  
  assert( zPath==0 || zPath[0]=='/' 
      || eType==SQLITE_OPEN_SUPER_JOURNAL || eType==SQLITE_OPEN_MAIN_JOURNAL 
  );
  rc = fillInUnixFile(pVfs, fd, pFile, zPath, ctrlFlags);

open_finished:
  if( rc!=SQLITE_OK ){
    sqlite3_free(p->pPreallocatedUnused);
  }

** If a Win32 native heap has been configured, this function will attempt to
** destroy and recreate it.  If the Win32 native heap is not isolated and/or
** the sqlite3_memory_used() function does not return zero, SQLITE_BUSY will
** be returned and no changes will be made to the Win32 native heap.
*/
SQLITE_API int sqlite3_win32_reset_heap(){
  int rc;
  MUTEX_LOGIC( sqlite3_mutex *pMainMtx; ) /* The main static mutex */
  MUTEX_LOGIC( sqlite3_mutex *pMem; )    /* The memsys static mutex */
  MUTEX_LOGIC( pMainMtx = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN); )
  MUTEX_LOGIC( pMem = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM); )
  sqlite3_mutex_enter(pMainMtx);
  sqlite3_mutex_enter(pMem);
  winMemAssertMagic();
  if( winMemGetHeap()!=NULL && winMemGetOwned() && sqlite3_memory_used()==0 ){
    /*
    ** At this point, there should be no outstanding memory allocations on
    ** the heap.  Also, since both the main and memsys locks are currently
    ** being held by us, no other function (i.e. from another thread) should
    ** be able to even access the heap.  Attempt to destroy and recreate our
    ** isolated Win32 native heap now.
    */
    assert( winMemGetHeap()!=NULL );
    assert( winMemGetOwned() );
    assert( sqlite3_memory_used()==0 );

  }else{
    /*
    ** The Win32 native heap cannot be modified because it may be in use.
    */
    rc = SQLITE_BUSY;
  }
  sqlite3_mutex_leave(pMem);
  sqlite3_mutex_leave(pMainMtx);
  return rc;
}
#endif /* SQLITE_WIN32_MALLOC */

/*
** This function outputs the specified (ANSI) string to the Win32 debugger
** (if available).

  int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
  int isCreate     = (flags & SQLITE_OPEN_CREATE);
  int isReadonly   = (flags & SQLITE_OPEN_READONLY);
  int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);

#ifndef NDEBUG
  int isOpenJournal = (isCreate && (
        eType==SQLITE_OPEN_SUPER_JOURNAL
     || eType==SQLITE_OPEN_MAIN_JOURNAL
     || eType==SQLITE_OPEN_WAL
  ));
#endif

  OSTRACE(("OPEN name=%s, pFile=%p, flags=%x, pOutFlags=%p\n",
           zUtf8Name, id, flags, pOutFlags));

  /* Check the following statements are true:
  **
  **   (a) Exactly one of the READWRITE and READONLY flags must be set, and
  **   (b) if CREATE is set, then READWRITE must also be set, and
  **   (c) if EXCLUSIVE is set, then CREATE must also be set.
  **   (d) if DELETEONCLOSE is set, then CREATE must also be set.
  */
  assert((isReadonly==0 || isReadWrite==0) && (isReadWrite || isReadonly));
  assert(isCreate==0 || isReadWrite);
  assert(isExclusive==0 || isCreate);
  assert(isDelete==0 || isCreate);

  /* The main DB, main journal, WAL file and super-journal are never
  ** automatically deleted. Nor are they ever temporary files.  */
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_DB );
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_JOURNAL );
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_SUPER_JOURNAL );
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_WAL );

  /* Assert that the upper layer has set one of the "file-type" flags. */
  assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB
       || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL
       || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_SUPER_JOURNAL
       || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL
  );

  assert( pFile!=0 );
  memset(pFile, 0, sizeof(winFile));
  pFile->h = INVALID_HANDLE_VALUE;

  assert( pOutFlags!=0 );  /* True because flags==SQLITE_OPEN_MAIN_DB */
  *pOutFlags = flags | SQLITE_OPEN_MEMORY;
  p->base.pMethods = &memdb_io_methods;
  p->szMax = sqlite3GlobalConfig.mxMemdbSize;
  return SQLITE_OK;
}

#if 0 /* Only used to delete rollback journals, super-journals, and WAL
      ** files, none of which exist in memdb.  So this routine is never used */
/*
** Delete the file located at zPath. If the dirSync argument is true,
** ensure the file-system modifications are synced to disk before
** returning.
*/
static int memdbDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){

** (4) Reads from the database file are either aligned on a page boundary and
**     an integer multiple of the page size in length or are taken from the
**     first 100 bytes of the database file.
** 
** (5) All writes to the database file are synced prior to the rollback journal
**     being deleted, truncated, or zeroed.
** 
** (6) If a super-journal file is used, then all writes to the database file
**     are synced prior to the super-journal being deleted.
** 
** Definition: Two databases (or the same database at two points it time)
** are said to be "logically equivalent" if they give the same answer to
** all queries.  Note in particular the content of freelist leaf
** pages can be changed arbitrarily without affecting the logical equivalence
** of the database.
** 

**   The changeCountDone flag is inspected. If it is true, the work of
**   updating the change-counter is omitted for the current transaction.
**
**   This mechanism means that when running in exclusive mode, a connection 
**   need only update the change-counter once, for the first transaction
**   committed.
**
** setSuper
**
**   When PagerCommitPhaseOne() is called to commit a transaction, it may
**   (or may not) specify a super-journal name to be written into the 
**   journal file before it is synced to disk.
**
**   Whether or not a journal file contains a super-journal pointer affects 
**   the way in which the journal file is finalized after the transaction is 
**   committed or rolled back when running in "journal_mode=PERSIST" mode.
**   If a journal file does not contain a super-journal pointer, it is
**   finalized by overwriting the first journal header with zeroes. If
**   it does contain a super-journal pointer the journal file is finalized 
**   by truncating it to zero bytes, just as if the connection were 
**   running in "journal_mode=truncate" mode.
**
**   Journal files that contain super-journal pointers cannot be finalized
**   simply by overwriting the first journal-header with zeroes, as the
**   super-journal pointer could interfere with hot-journal rollback of any
**   subsequently interrupted transaction that reuses the journal file.
**
**   The flag is cleared as soon as the journal file is finalized (either
**   by PagerCommitPhaseTwo or PagerRollback). If an IO error prevents the
**   journal file from being successfully finalized, the setSuper flag
**   is cleared anyway (and the pager will move to ERROR state).
**
** doNotSpill
**
**   This variables control the behavior of cache-spills  (calls made by
**   the pcache module to the pagerStress() routine to write cached data
**   to the file-system in order to free up memory).

  ** or the journal_mode).  From another view, these class members describe
  ** the "state" of the pager, while other class members describe the
  ** "configuration" of the pager.
  */
  u8 eState;                  /* Pager state (OPEN, READER, WRITER_LOCKED..) */
  u8 eLock;                   /* Current lock held on database file */
  u8 changeCountDone;         /* Set after incrementing the change-counter */
  u8 setSuper;                /* Super-jrnl name is written into jrnl */
  u8 doNotSpill;              /* Do not spill the cache when non-zero */
  u8 subjInMemory;            /* True to use in-memory sub-journals */
  u8 bUseFetch;               /* True to use xFetch() */
  u8 hasHeldSharedLock;       /* True if a shared lock has ever been held */
  Pgno dbSize;                /* Number of pages in the database */
  Pgno dbOrigSize;            /* dbSize before the current transaction */
  Pgno dbFileSize;            /* Number of pages in the database file */

      assert( pPager->errCode==SQLITE_OK );
      if( !pagerUseWal(pPager) ){
        assert( p->eLock>=RESERVED_LOCK );
      }
      assert( pPager->dbSize==pPager->dbOrigSize );
      assert( pPager->dbOrigSize==pPager->dbFileSize );
      assert( pPager->dbOrigSize==pPager->dbHintSize );
      assert( pPager->setSuper==0 );
      break;

    case PAGER_WRITER_CACHEMOD:
      assert( p->eLock!=UNKNOWN_LOCK );
      assert( pPager->errCode==SQLITE_OK );
      if( !pagerUseWal(pPager) ){
        /* It is possible that if journal_mode=wal here that neither the

#define pager_pagehash(X)  0
#define pager_set_pagehash(X)
#define CHECK_PAGE(x)
#endif  /* SQLITE_CHECK_PAGES */

/*
** When this is called the journal file for pager pPager must be open.
** This function attempts to read a super-journal file name from the 
** end of the file and, if successful, copies it into memory supplied 
** by the caller. See comments above writeSuperJournal() for the format
** used to store a super-journal file name at the end of a journal file.
**
** zSuper must point to a buffer of at least nSuper bytes allocated by
** the caller. This should be sqlite3_vfs.mxPathname+1 (to ensure there is
** enough space to write the super-journal name). If the super-journal
** name in the journal is longer than nSuper bytes (including a
** nul-terminator), then this is handled as if no super-journal name
** were present in the journal.
**
** If a super-journal file name is present at the end of the journal
** file, then it is copied into the buffer pointed to by zSuper. A
** nul-terminator byte is appended to the buffer following the
** super-journal file name.
**
** If it is determined that no super-journal file name is present 
** zSuper[0] is set to 0 and SQLITE_OK returned.
**
** If an error occurs while reading from the journal file, an SQLite
** error code is returned.
*/
static int readSuperJournal(sqlite3_file *pJrnl, char *zSuper, u32 nSuper){
  int rc;                    /* Return code */
  u32 len;                   /* Length in bytes of super-journal name */
  i64 szJ;                   /* Total size in bytes of journal file pJrnl */
  u32 cksum;                 /* MJ checksum value read from journal */
  u32 u;                     /* Unsigned loop counter */
  unsigned char aMagic[8];   /* A buffer to hold the magic header */
  zSuper[0] = '\0';

  if( SQLITE_OK!=(rc = sqlite3OsFileSize(pJrnl, &szJ))
   || szJ<16
   || SQLITE_OK!=(rc = read32bits(pJrnl, szJ-16, &len))
   || len>=nSuper 
   || len>szJ-16
   || len==0 
   || SQLITE_OK!=(rc = read32bits(pJrnl, szJ-12, &cksum))
   || SQLITE_OK!=(rc = sqlite3OsRead(pJrnl, aMagic, 8, szJ-8))
   || memcmp(aMagic, aJournalMagic, 8)
   || SQLITE_OK!=(rc = sqlite3OsRead(pJrnl, zSuper, len, szJ-16-len))
  ){
    return rc;
  }

  /* See if the checksum matches the super-journal name */
  for(u=0; u<len; u++){
    cksum -= zSuper[u];
  }
  if( cksum ){
    /* If the checksum doesn't add up, then one or more of the disk sectors
    ** containing the super-journal filename is corrupted. This means
    ** definitely roll back, so just return SQLITE_OK and report a (nul)
    ** super-journal filename.
    */
    len = 0;
  }
  zSuper[len] = '\0';
  zSuper[len+1] = '\0';
   
  return SQLITE_OK;
}

/*
** Return the offset of the sector boundary at or immediately 
** following the value in pPager->journalOff, assuming a sector 

  pPager->journalOff += JOURNAL_HDR_SZ(pPager);
  return rc;
}


/*
** Write the supplied super-journal name into the journal file for pager
** pPager at the current location. The super-journal name must be the last
** thing written to a journal file. If the pager is in full-sync mode, the
** journal file descriptor is advanced to the next sector boundary before
** anything is written. The format is:
**
**   + 4 bytes: PAGER_MJ_PGNO.
**   + N bytes: super-journal filename in utf-8.
**   + 4 bytes: N (length of super-journal name in bytes, no nul-terminator).
**   + 4 bytes: super-journal name checksum.
**   + 8 bytes: aJournalMagic[].
**
** The super-journal page checksum is the sum of the bytes in thesuper-journal
** name, where each byte is interpreted as a signed 8-bit integer.
**
** If zSuper is a NULL pointer (occurs for a single database transaction), 
** this call is a no-op.
*/
static int writeSuperJournal(Pager *pPager, const char *zSuper){
  int rc;                          /* Return code */
  int nSuper;                      /* Length of string zSuper */
  i64 iHdrOff;                     /* Offset of header in journal file */
  i64 jrnlSize;                    /* Size of journal file on disk */
  u32 cksum = 0;                   /* Checksum of string zSuper */

  assert( pPager->setSuper==0 );
  assert( !pagerUseWal(pPager) );

  if( !zSuper 
   || pPager->journalMode==PAGER_JOURNALMODE_MEMORY 
   || !isOpen(pPager->jfd)
  ){
    return SQLITE_OK;
  }
  pPager->setSuper = 1;
  assert( pPager->journalHdr <= pPager->journalOff );

  /* Calculate the length in bytes and the checksum of zSuper */
  for(nSuper=0; zSuper[nSuper]; nSuper++){
    cksum += zSuper[nSuper];
  }

  /* If in full-sync mode, advance to the next disk sector before writing
  ** the super-journal name. This is in case the previous page written to
  ** the journal has already been synced.
  */
  if( pPager->fullSync ){
    pPager->journalOff = journalHdrOffset(pPager);
  }
  iHdrOff = pPager->journalOff;

  /* Write the super-journal data to the end of the journal file. If
  ** an error occurs, return the error code to the caller.
  */
  if( (0 != (rc = write32bits(pPager->jfd, iHdrOff, PAGER_MJ_PGNO(pPager))))
   || (0 != (rc = sqlite3OsWrite(pPager->jfd, zSuper, nSuper, iHdrOff+4)))
   || (0 != (rc = write32bits(pPager->jfd, iHdrOff+4+nSuper, nSuper)))
   || (0 != (rc = write32bits(pPager->jfd, iHdrOff+4+nSuper+4, cksum)))
   || (0 != (rc = sqlite3OsWrite(pPager->jfd, aJournalMagic, 8,
                                 iHdrOff+4+nSuper+8)))
  ){
    return rc;
  }
  pPager->journalOff += (nSuper+20);

  /* If the pager is in peristent-journal mode, then the physical 
  ** journal-file may extend past the end of the super-journal name
  ** and 8 bytes of magic data just written to the file. This is 
  ** dangerous because the code to rollback a hot-journal file
  ** will not be able to find the super-journal name to determine 
  ** whether or not the journal is hot. 
  **
  ** Easiest thing to do in this scenario is to truncate the journal 
  ** file to the required size.
  */ 
  if( SQLITE_OK==(rc = sqlite3OsFileSize(pPager->jfd, &jrnlSize))
   && jrnlSize>pPager->journalOff

    if( USEFETCH(pPager) ) sqlite3OsUnfetch(pPager->fd, 0, 0);
    pPager->errCode = SQLITE_OK;
    setGetterMethod(pPager);
  }

  pPager->journalOff = 0;
  pPager->journalHdr = 0;
  pPager->setSuper = 0;
}

/*
** This function is called whenever an IOERR or FULL error that requires
** the pager to transition into the ERROR state may ahve occurred.
** The first argument is a pointer to the pager structure, the second 
** the error-code about to be returned by a pager API function. The 

** database then the IO error code is returned to the user. If the 
** operation to finalize the journal file fails, then the code still
** tries to unlock the database file if not in exclusive mode. If the
** unlock operation fails as well, then the first error code related
** to the first error encountered (the journal finalization one) is
** returned.
*/
static int pager_end_transaction(Pager *pPager, int hasSuper, int bCommit){
  int rc = SQLITE_OK;      /* Error code from journal finalization operation */
  int rc2 = SQLITE_OK;     /* Error code from db file unlock operation */

  /* Do nothing if the pager does not have an open write transaction
  ** or at least a RESERVED lock. This function may be called when there
  ** is no write-transaction active but a RESERVED or greater lock is
  ** held under two circumstances:

          rc = sqlite3OsSync(pPager->jfd, pPager->syncFlags);
        }
      }
      pPager->journalOff = 0;
    }else if( pPager->journalMode==PAGER_JOURNALMODE_PERSIST
      || (pPager->exclusiveMode && pPager->journalMode!=PAGER_JOURNALMODE_WAL)
    ){
      rc = zeroJournalHdr(pPager, hasSuper||pPager->tempFile);
      pPager->journalOff = 0;
    }else{
      /* This branch may be executed with Pager.journalMode==MEMORY if
      ** a hot-journal was just rolled back. In this case the journal
      ** file should be closed and deleted. If this connection writes to
      ** the database file, it will do so using an in-memory journal.
      */

  if( !pPager->exclusiveMode 
   && (!pagerUseWal(pPager) || sqlite3WalExclusiveMode(pPager->pWal, 0))
  ){
    rc2 = pagerUnlockDb(pPager, SHARED_LOCK);
  }
  pPager->eState = PAGER_READER;
  pPager->setSuper = 0;

  return (rc==SQLITE_OK?rc2:rc);
}

/*
** Execute a rollback if a transaction is active and unlock the 
** database file. 

    }
    sqlite3PcacheRelease(pPg);
  }
  return rc;
}

/*
** Parameter zSuper is the name of a super-journal file. A single journal
** file that referred to the super-journal file has just been rolled back.
** This routine checks if it is possible to delete the super-journal file,
** and does so if it is.
**
** Argument zSuper may point to Pager.pTmpSpace. So that buffer is not 
** available for use within this function.
**
** When a super-journal file is created, it is populated with the names 
** of all of its child journals, one after another, formatted as utf-8 
** encoded text. The end of each child journal file is marked with a 
** nul-terminator byte (0x00). i.e. the entire contents of a super-journal
** file for a transaction involving two databases might be:
**
**   "/home/bill/a.db-journal\x00/home/bill/b.db-journal\x00"
**
** A super-journal file may only be deleted once all of its child 
** journals have been rolled back.
**
** This function reads the contents of the super-journal file into 
** memory and loops through each of the child journal names. For
** each child journal, it checks if:
**
**   * if the child journal exists, and if so
**   * if the child journal contains a reference to super-journal 
**     file zSuper
**
** If a child journal can be found that matches both of the criteria
** above, this function returns without doing anything. Otherwise, if
** no such child journal can be found, file zSuper is deleted from
** the file-system using sqlite3OsDelete().
**
** If an IO error within this function, an error code is returned. This
** function allocates memory by calling sqlite3Malloc(). If an allocation
** fails, SQLITE_NOMEM is returned. Otherwise, if no IO or malloc errors 
** occur, SQLITE_OK is returned.
**
** TODO: This function allocates a single block of memory to load
** the entire contents of the super-journal file. This could be
** a couple of kilobytes or so - potentially larger than the page 
** size.
*/
static int pager_delsuper(Pager *pPager, const char *zSuper){
  sqlite3_vfs *pVfs = pPager->pVfs;
  int rc;                   /* Return code */
  sqlite3_file *pSuper;     /* Malloc'd super-journal file descriptor */
  sqlite3_file *pJournal;   /* Malloc'd child-journal file descriptor */
  char *zSuperJournal = 0;  /* Contents of super-journal file */
  i64 nSuperJournal;        /* Size of super-journal file */
  char *zJournal;           /* Pointer to one journal within MJ file */
  char *zSuperPtr;          /* Space to hold super-journal filename */
  int nSuperPtr;            /* Amount of space allocated to zSuperPtr[] */

  /* Allocate space for both the pJournal and pSuper file descriptors.
  ** If successful, open the super-journal file for reading.
  */
  pSuper = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile * 2);
  pJournal = (sqlite3_file *)(((u8 *)pSuper) + pVfs->szOsFile);
  if( !pSuper ){
    rc = SQLITE_NOMEM_BKPT;
  }else{
    const int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_SUPER_JOURNAL);
    rc = sqlite3OsOpen(pVfs, zSuper, pSuper, flags, 0);
  }
  if( rc!=SQLITE_OK ) goto delsuper_out;

  /* Load the entire super-journal file into space obtained from
  ** sqlite3_malloc() and pointed to by zSuperJournal.   Also obtain
  ** sufficient space (in zSuperPtr) to hold the names of super-journal
  ** files extracted from regular rollback-journals.
  */
  rc = sqlite3OsFileSize(pSuper, &nSuperJournal);
  if( rc!=SQLITE_OK ) goto delsuper_out;
  nSuperPtr = pVfs->mxPathname+1;
  zSuperJournal = sqlite3Malloc(nSuperJournal + nSuperPtr + 2);
  if( !zSuperJournal ){
    rc = SQLITE_NOMEM_BKPT;
    goto delsuper_out;
  }
  zSuperPtr = &zSuperJournal[nSuperJournal+2];
  rc = sqlite3OsRead(pSuper, zSuperJournal, (int)nSuperJournal, 0);
  if( rc!=SQLITE_OK ) goto delsuper_out;
  zSuperJournal[nSuperJournal] = 0;
  zSuperJournal[nSuperJournal+1] = 0;

  zJournal = zSuperJournal;
  while( (zJournal-zSuperJournal)<nSuperJournal ){
    int exists;
    rc = sqlite3OsAccess(pVfs, zJournal, SQLITE_ACCESS_EXISTS, &exists);
    if( rc!=SQLITE_OK ){
      goto delsuper_out;
    }
    if( exists ){
      /* One of the journals pointed to by the super-journal exists.
      ** Open it and check if it points at the super-journal. If
      ** so, return without deleting the super-journal file.
      ** NB:  zJournal is really a MAIN_JOURNAL.  But call it a 
      ** SUPER_JOURNAL here so that the VFS will not send the zJournal
      ** name into sqlite3_database_file_object().
      */
      int c;
      int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_SUPER_JOURNAL);
      rc = sqlite3OsOpen(pVfs, zJournal, pJournal, flags, 0);
      if( rc!=SQLITE_OK ){
        goto delsuper_out;
      }

      rc = readSuperJournal(pJournal, zSuperPtr, nSuperPtr);
      sqlite3OsClose(pJournal);
      if( rc!=SQLITE_OK ){
        goto delsuper_out;
      }

      c = zSuperPtr[0]!=0 && strcmp(zSuperPtr, zSuper)==0;
      if( c ){
        /* We have a match. Do not delete the super-journal file. */
        goto delsuper_out;
      }
    }
    zJournal += (sqlite3Strlen30(zJournal)+1);
  }
 
  sqlite3OsClose(pSuper);
  rc = sqlite3OsDelete(pVfs, zSuper, 0);

delsuper_out:
  sqlite3_free(zSuperJournal);
  if( pSuper ){
    sqlite3OsClose(pSuper);
    assert( !isOpen(pJournal) );
    sqlite3_free(pSuper);
  }
  return rc;
}


/*
** This function is used to change the actual size of the database 

}

/*
** Set the value of the Pager.sectorSize variable for the given
** pager based on the value returned by the xSectorSize method
** of the open database file. The sector size will be used 
** to determine the size and alignment of journal header and 
** super-journal pointers within created journal files.
**
** For temporary files the effective sector size is always 512 bytes.
**
** Otherwise, for non-temporary files, the effective sector size is
** the value returned by the xSectorSize() method rounded up to 32 if
** it is less than 32, or rounded down to MAX_SECTOR_SIZE if it
** is greater than MAX_SECTOR_SIZE.

  sqlite3_vfs *pVfs = pPager->pVfs;
  i64 szJ;                 /* Size of the journal file in bytes */
  u32 nRec;                /* Number of Records in the journal */
  u32 u;                   /* Unsigned loop counter */
  Pgno mxPg = 0;           /* Size of the original file in pages */
  int rc;                  /* Result code of a subroutine */
  int res = 1;             /* Value returned by sqlite3OsAccess() */
  char *zSuper = 0;        /* Name of super-journal file if any */
  int needPagerReset;      /* True to reset page prior to first page rollback */
  int nPlayback = 0;       /* Total number of pages restored from journal */
  u32 savedPageSize = pPager->pageSize;

  /* Figure out how many records are in the journal.  Abort early if
  ** the journal is empty.
  */
  assert( isOpen(pPager->jfd) );
  rc = sqlite3OsFileSize(pPager->jfd, &szJ);
  if( rc!=SQLITE_OK ){
    goto end_playback;
  }

  /* Read the super-journal name from the journal, if it is present.
  ** If a super-journal file name is specified, but the file is not
  ** present on disk, then the journal is not hot and does not need to be
  ** played back.
  **
  ** TODO: Technically the following is an error because it assumes that
  ** buffer Pager.pTmpSpace is (mxPathname+1) bytes or larger. i.e. that
  ** (pPager->pageSize >= pPager->pVfs->mxPathname+1). Using os_unix.c,
  ** mxPathname is 512, which is the same as the minimum allowable value
  ** for pageSize.
  */
  zSuper = pPager->pTmpSpace;
  rc = readSuperJournal(pPager->jfd, zSuper, pPager->pVfs->mxPathname+1);
  if( rc==SQLITE_OK && zSuper[0] ){
    rc = sqlite3OsAccess(pVfs, zSuper, SQLITE_ACCESS_EXISTS, &res);
  }
  zSuper = 0;
  if( rc!=SQLITE_OK || !res ){
    goto end_playback;
  }
  pPager->journalOff = 0;
  needPagerReset = isHot;

  /* This loop terminates either when a readJournalHdr() or 

  ** update the change-counter at all. This may lead to cache inconsistency
  ** problems for other processes at some point in the future. So, just
  ** in case this has happened, clear the changeCountDone flag now.
  */
  pPager->changeCountDone = pPager->tempFile;

  if( rc==SQLITE_OK ){
    zSuper = pPager->pTmpSpace;
    rc = readSuperJournal(pPager->jfd, zSuper, pPager->pVfs->mxPathname+1);
    testcase( rc!=SQLITE_OK );
  }
  if( rc==SQLITE_OK
   && (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN)
  ){
    rc = sqlite3PagerSync(pPager, 0);
  }
  if( rc==SQLITE_OK ){
    rc = pager_end_transaction(pPager, zSuper[0]!='\0', 0);
    testcase( rc!=SQLITE_OK );
  }
  if( rc==SQLITE_OK && zSuper[0] && res ){
    /* If there was a super-journal and this routine will return success,
    ** see if it is possible to delete the super-journal.
    */
    rc = pager_delsuper(pPager, zSuper);
    testcase( rc!=SQLITE_OK );
  }
  if( isHot && nPlayback ){
    sqlite3_log(SQLITE_NOTICE_RECOVER_ROLLBACK, "recovered %d pages from %s",
                nPlayback, pPager->zJournal);
  }

  }
  return rc;
}
#endif

/*
** Playback savepoint pSavepoint. Or, if pSavepoint==NULL, then playback
** the entire super-journal file. The case pSavepoint==NULL occurs when 
** a ROLLBACK TO command is invoked on a SAVEPOINT that is a transaction 
** savepoint.
**
** When pSavepoint is not NULL (meaning a non-transaction savepoint is 
** being rolled back), then the rollback consists of up to three stages,
** performed in the order specified:
**

**
** If the current size of the database file is 0 but a journal file
** exists, that is probably an old journal left over from a prior
** database with the same name. In this case the journal file is
** just deleted using OsDelete, *pExists is set to 0 and SQLITE_OK
** is returned.
**
** This routine does not check if there is a super-journal filename
** at the end of the file. If there is, and that super-journal file
** does not exist, then the journal file is not really hot. In this
** case this routine will return a false-positive. The pager_playback()
** routine will discover that the journal file is not really hot and 
** will not roll it back. 
**
** If a hot-journal file is found to exist, *pExists is set to 1 and 
** SQLITE_OK returned. If no hot-journal file is present, *pExists is

    /* Write the first journal header to the journal file and open 
    ** the sub-journal if necessary.
    */
    if( rc==SQLITE_OK ){
      /* TODO: Check if all of these are really required. */
      pPager->nRec = 0;
      pPager->journalOff = 0;
      pPager->setSuper = 0;
      pPager->journalHdr = 0;
      rc = writeJournalHdr(pPager);
    }
  }

  if( rc!=SQLITE_OK ){
    sqlite3BitvecDestroy(pPager->pInJournal);

/*
** Sync the database file to disk. This is a no-op for in-memory databases
** or pages with the Pager.noSync flag set.
**
** If successful, or if called on a pager for which it is a no-op, this
** function returns SQLITE_OK. Otherwise, an IO error code is returned.
*/
SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager, const char *zSuper){
  int rc = SQLITE_OK;
  void *pArg = (void*)zSuper;
  rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SYNC, pArg);
  if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
  if( rc==SQLITE_OK && !pPager->noSync ){
    assert( !MEMDB );
    rc = sqlite3OsSync(pPager->fd, pPager->syncFlags);
  }
  return rc;

      rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
    }
  }
  return rc;
}

/*
** Sync the database file for the pager pPager. zSuper points to the name
** of a super-journal file that should be written into the individual
** journal file. zSuper may be NULL, which is interpreted as no 
** super-journal (a single database transaction).
**
** This routine ensures that:
**
**   * The database file change-counter is updated,
**   * the journal is synced (unless the atomic-write optimization is used),
**   * all dirty pages are written to the database file, 
**   * the database file is truncated (if required), and
**   * the database file synced. 
**
** The only thing that remains to commit the transaction is to finalize 
** (delete, truncate or zero the first part of) the journal file (or 
** delete the super-journal file if specified).
**
** Note that if zSuper==NULL, this does not overwrite a previous value
** passed to an sqlite3PagerCommitPhaseOne() call.
**
** If the final parameter - noSync - is true, then the database file itself
** is not synced. The caller must call sqlite3PagerSync() directly to
** sync the database file before calling CommitPhaseTwo() to delete the
** journal file in this case.
*/
SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(
  Pager *pPager,                  /* Pager object */
  const char *zSuper,            /* If not NULL, the super-journal name */
  int noSync                      /* True to omit the xSync on the db file */
){
  int rc = SQLITE_OK;             /* Return code */

  assert( pPager->eState==PAGER_WRITER_LOCKED
       || pPager->eState==PAGER_WRITER_CACHEMOD
       || pPager->eState==PAGER_WRITER_DBMOD
       || pPager->eState==PAGER_ERROR
  );
  assert( assert_pager_state(pPager) );

  /* If a prior error occurred, report that error again. */
  if( NEVER(pPager->errCode) ) return pPager->errCode;

  /* Provide the ability to easily simulate an I/O error during testing */
  if( sqlite3FaultSim(400) ) return SQLITE_IOERR;

  PAGERTRACE(("DATABASE SYNC: File=%s zSuper=%s nSize=%d\n", 
      pPager->zFilename, zSuper, pPager->dbSize));

  /* If no database changes have been made, return early. */
  if( pPager->eState<PAGER_WRITER_CACHEMOD ) return SQLITE_OK;

  assert( MEMDB==0 || pPager->tempFile );
  assert( isOpen(pPager->fd) || pPager->tempFile );
  if( 0==pagerFlushOnCommit(pPager, 1) ){

    }else{
      /* The bBatch boolean is true if the batch-atomic-write commit method
      ** should be used.  No rollback journal is created if batch-atomic-write
      ** is enabled.
      */
#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
      sqlite3_file *fd = pPager->fd;
      int bBatch = zSuper==0    /* An SQLITE_IOCAP_BATCH_ATOMIC commit */
        && (sqlite3OsDeviceCharacteristics(fd) & SQLITE_IOCAP_BATCH_ATOMIC)
        && !pPager->noSync
        && sqlite3JournalIsInMemory(pPager->jfd);
#else
#     define bBatch 0
#endif

      */
      if( bBatch==0 ){
        PgHdr *pPg;
        assert( isOpen(pPager->jfd) 
            || pPager->journalMode==PAGER_JOURNALMODE_OFF 
            || pPager->journalMode==PAGER_JOURNALMODE_WAL 
            );
        if( !zSuper && isOpen(pPager->jfd) 
         && pPager->journalOff==jrnlBufferSize(pPager) 
         && pPager->dbSize>=pPager->dbOrigSize
         && (!(pPg = sqlite3PcacheDirtyList(pPager->pPCache)) || 0==pPg->pDirty)
        ){
          /* Update the db file change counter via the direct-write method. The 
          ** following call will modify the in-memory representation of page 1 
          ** to include the updated change counter and then write page 1 
          ** directly to the database file. Because of the atomic-write 
          ** property of the host file-system, this is safe.
          */
          rc = pager_incr_changecounter(pPager, 1);
        }else{
          rc = sqlite3JournalCreate(pPager->jfd);
          if( rc==SQLITE_OK ){
            rc = pager_incr_changecounter(pPager, 0);
          }
        }
      }
#else  /* SQLITE_ENABLE_ATOMIC_WRITE */
#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
      if( zSuper ){
        rc = sqlite3JournalCreate(pPager->jfd);
        if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
        assert( bBatch==0 );
      }
#endif
      rc = pager_incr_changecounter(pPager, 0);
#endif /* !SQLITE_ENABLE_ATOMIC_WRITE */
      if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
  
      /* Write the super-journal name into the journal file. If a
      ** super-journal file name has already been written to the journal file, 
      ** or if zSuper is NULL (no super-journal), then this call is a no-op.
      */
      rc = writeSuperJournal(pPager, zSuper);
      if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
  
      /* Sync the journal file and write all dirty pages to the database.
      ** If the atomic-update optimization is being used, this sync will not 
      ** create the journal file or perform any real IO.
      **
      ** Because the change-counter page was just modified, unless the

        assert( pPager->eState==PAGER_WRITER_DBMOD );
        rc = pager_truncate(pPager, nNew);
        if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
      }
  
      /* Finally, sync the database file. */
      if( !noSync ){
        rc = sqlite3PagerSync(pPager, zSuper);
      }
      IOTRACE(("DBSYNC %p\n", pPager))
    }
  }

commit_phase_one_exit:
  if( rc==SQLITE_OK && !pagerUseWal(pPager) ){

  ){
    assert( pPager->journalOff==JOURNAL_HDR_SZ(pPager) || !pPager->journalOff );
    pPager->eState = PAGER_READER;
    return SQLITE_OK;
  }

  PAGERTRACE(("COMMIT %d\n", PAGERID(pPager)));
  rc = pager_end_transaction(pPager, pPager->setSuper, 1);
  return pager_error(pPager, rc);
}

/*
** If a write transaction is open, then all changes made within the 
** transaction are reverted and the current write-transaction is closed.
** The pager falls back to PAGER_READER state if successful, or PAGER_ERROR

  assert( assert_pager_state(pPager) );
  if( pPager->eState==PAGER_ERROR ) return pPager->errCode;
  if( pPager->eState<=PAGER_READER ) return SQLITE_OK;

  if( pagerUseWal(pPager) ){
    int rc2;
    rc = sqlite3PagerSavepoint(pPager, SAVEPOINT_ROLLBACK, -1);
    rc2 = pager_end_transaction(pPager, pPager->setSuper, 0);
    if( rc==SQLITE_OK ) rc = rc2;
  }else if( !isOpen(pPager->jfd) || pPager->eState==PAGER_WRITER_LOCKED ){
    int eState = pPager->eState;
    rc = pager_end_transaction(pPager, 0, 0);
    if( !MEMDB && eState>PAGER_WRITER_LOCKED ){
      /* This can happen using journal_mode=off. Move the pager to the error 
      ** state to indicate that the contents of the cache may not be trusted.

** sharing the same database file, each connection has it own
** private Btree object for the file and each of those Btrees points
** to this one BtShared object.  BtShared.nRef is the number of
** connections currently sharing this database file.
**
** Fields in this structure are accessed under the BtShared.mutex
** mutex, except for nRef and pNext which are accessed under the
** global SQLITE_MUTEX_STATIC_MAIN mutex.  The pPager field
** may not be modified once it is initially set as long as nRef>0.
** The pSchema field may be set once under BtShared.mutex and
** thereafter is unchanged as long as nRef>0.
**
** isPending:
**
**   If a BtShared client fails to obtain a write-lock on a database

#ifndef SQLITE_OMIT_SHARED_CACHE
/*
** A list of BtShared objects that are eligible for participation
** in shared cache.  This variable has file scope during normal builds,
** but the test harness needs to access it so we make it global for 
** test builds.
**
** Access to this variable is protected by SQLITE_MUTEX_STATIC_MAIN.
*/
#ifdef SQLITE_TEST
SQLITE_PRIVATE BtShared *SQLITE_WSD sqlite3SharedCacheList = 0;
#else
static BtShared *SQLITE_WSD sqlite3SharedCacheList = 0;
#endif
#endif /* SQLITE_OMIT_SHARED_CACHE */

  /* Figure out the root-page that the lock should be held on. For table
  ** b-trees, this is just the root page of the b-tree being read or
  ** written. For index b-trees, it is the root page of the associated
  ** table.  */
  if( isIndex ){
    HashElem *p;
    int bSeen = 0;
    for(p=sqliteHashFirst(&pSchema->idxHash); p; p=sqliteHashNext(p)){
      Index *pIdx = (Index *)sqliteHashData(p);
      if( pIdx->tnum==(int)iRoot ){
        if( bSeen ){
          /* Two or more indexes share the same root page.  There must
          ** be imposter tables.  So just return true.  The assert is not
          ** useful in that case. */
          return 1;
        }
        iTab = pIdx->pTable->tnum;
        bSeen = 1;
      }
    }
  }else{
    iTab = iRoot;
  }

  /* Search for the required lock. Either a write-lock on root-page iTab, a 

  assert( sqlite3BtreeHoldsMutex(p) );
  assert( eLock==READ_LOCK || eLock==WRITE_LOCK );
  assert( p->db!=0 );

  /* A connection with the read-uncommitted flag set will never try to
  ** obtain a read-lock using this function. The only read-lock obtained
  ** by a connection in read-uncommitted mode is on the sqlite_schema 
  ** table, and that lock is obtained in BtreeBeginTrans().  */
  assert( 0==(p->db->flags&SQLITE_ReadUncommit) || eLock==WRITE_LOCK );

  /* This function should only be called on a sharable b-tree after it 
  ** has been determined that no other b-tree holds a conflicting lock.  */
  assert( p->sharable );
  assert( SQLITE_OK==querySharedCacheTableLock(p, iTable, eLock) );

  Pgno iPtrmap;     /* The pointer map page number */
  int offset;       /* Offset in pointer map page */
  int rc;           /* Return code from subfunctions */

  if( *pRC ) return;

  assert( sqlite3_mutex_held(pBt->mutex) );
  /* The super-journal page number must never be used as a pointer map page */
  assert( 0==PTRMAP_ISPAGE(pBt, PENDING_BYTE_PAGE(pBt)) );

  assert( pBt->autoVacuum );
  if( key==0 ){
    *pRC = SQLITE_CORRUPT_BKPT;
    return;
  }

    **
    ** Check to see if iFreeBlk should be coalesced onto the end of iStart.
    */
    if( iFreeBlk && iEnd+3>=iFreeBlk ){
      nFrag = iFreeBlk - iEnd;
      if( iEnd>iFreeBlk ) return SQLITE_CORRUPT_PAGE(pPage);
      iEnd = iFreeBlk + get2byte(&data[iFreeBlk+2]);
      if( iEnd > pPage->pBt->usableSize ){
        return SQLITE_CORRUPT_PAGE(pPage);
      }
      iSize = iEnd - iStart;
      iFreeBlk = get2byte(&data[iFreeBlk]);
    }
  
    /* If iPtr is another freeblock (that is, if iPtr is not the freelist

            return rc;
          }
        }
      }
#if SQLITE_THREADSAFE
      mutexOpen = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_OPEN);
      sqlite3_mutex_enter(mutexOpen);
      mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
      sqlite3_mutex_enter(mutexShared);
#endif
      for(pBt=GLOBAL(BtShared*,sqlite3SharedCacheList); pBt; pBt=pBt->pNext){
        assert( pBt->nRef>0 );
        if( 0==strcmp(zFullPathname, sqlite3PagerFilename(pBt->pPager, 0))
                 && sqlite3PagerVfs(pBt->pPager)==pVfs ){
          int iDb;

   
#if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)
    /* Add the new BtShared object to the linked list sharable BtShareds.
    */
    pBt->nRef = 1;
    if( p->sharable ){
      MUTEX_LOGIC( sqlite3_mutex *mutexShared; )
      MUTEX_LOGIC( mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);)
      if( SQLITE_THREADSAFE && sqlite3GlobalConfig.bCoreMutex ){
        pBt->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_FAST);
        if( pBt->mutex==0 ){
          rc = SQLITE_NOMEM_BKPT;
          goto btree_open_out;
        }
      }

** Decrement the BtShared.nRef counter.  When it reaches zero,
** remove the BtShared structure from the sharing list.  Return
** true if the BtShared.nRef counter reaches zero and return
** false if it is still positive.
*/
static int removeFromSharingList(BtShared *pBt){
#ifndef SQLITE_OMIT_SHARED_CACHE
  MUTEX_LOGIC( sqlite3_mutex *pMainMtx; )
  BtShared *pList;
  int removed = 0;

  assert( sqlite3_mutex_notheld(pBt->mutex) );
  MUTEX_LOGIC( pMainMtx = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN); )
  sqlite3_mutex_enter(pMainMtx);
  pBt->nRef--;
  if( pBt->nRef<=0 ){
    if( GLOBAL(BtShared*,sqlite3SharedCacheList)==pBt ){
      GLOBAL(BtShared*,sqlite3SharedCacheList) = pBt->pNext;
    }else{
      pList = GLOBAL(BtShared*,sqlite3SharedCacheList);
      while( ALWAYS(pList) && pList->pNext!=pBt ){
        pList=pList->pNext;
      }
      if( ALWAYS(pList) ){
        pList->pNext = pBt->pNext;
      }
    }
    if( SQLITE_THREADSAFE ){
      sqlite3_mutex_free(pBt->mutex);
    }
    removed = 1;
  }
  sqlite3_mutex_leave(pMainMtx);
  return removed;
#else
  return 1;
#endif
}

/*

    }
  }
#endif

  /* Any read-only or read-write transaction implies a read-lock on 
  ** page 1. So if some other shared-cache client already has a write-lock 
  ** on page 1, the transaction cannot be opened. */
  rc = querySharedCacheTableLock(p, SCHEMA_ROOT, READ_LOCK);
  if( SQLITE_OK!=rc ) goto trans_begun;

  pBt->btsFlags &= ~BTS_INITIALLY_EMPTY;
  if( pBt->nPage==0 ) pBt->btsFlags |= BTS_INITIALLY_EMPTY;
  do {
    sqlite3PagerWalDb(pPager, p->db);

** At the end of this call, the rollback journal still exists on the
** disk and we are still holding all locks, so the transaction has not
** committed.  See sqlite3BtreeCommitPhaseTwo() for the second phase of the
** commit process.
**
** This call is a no-op if no write-transaction is currently active on pBt.
**
** Otherwise, sync the database file for the btree pBt. zSuperJrnl points to
** the name of a super-journal file that should be written into the
** individual journal file, or is NULL, indicating no super-journal file 
** (single database transaction).
**
** When this is called, the super-journal should already have been
** created, populated with this journal pointer and synced to disk.
**
** Once this is routine has returned, the only thing required to commit
** the write-transaction for this database file is to delete the journal.
*/
SQLITE_PRIVATE int sqlite3BtreeCommitPhaseOne(Btree *p, const char *zSuperJrnl){
  int rc = SQLITE_OK;
  if( p->inTrans==TRANS_WRITE ){
    BtShared *pBt = p->pBt;
    sqlite3BtreeEnter(p);
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pBt->autoVacuum ){
      rc = autoVacuumCommit(pBt);
      if( rc!=SQLITE_OK ){
        sqlite3BtreeLeave(p);
        return rc;
      }
    }
    if( pBt->bDoTruncate ){
      sqlite3PagerTruncateImage(pBt->pPager, pBt->nPage);
    }
#endif
    rc = sqlite3PagerCommitPhaseOne(pBt->pPager, zSuperJrnl, 0);
    sqlite3BtreeLeave(p);
  }
  return rc;
}

/*
** This function is called from both BtreeCommitPhaseTwo() and BtreeRollback()

** drop locks.
**
** Normally, if an error occurs while the pager layer is attempting to 
** finalize the underlying journal file, this function returns an error and
** the upper layer will attempt a rollback. However, if the second argument
** is non-zero then this b-tree transaction is part of a multi-file 
** transaction. In this case, the transaction has already been committed 
** (by deleting a super-journal file) and the caller will ignore this 
** functions return code. So, even if an error occurs in the pager layer,
** reset the b-tree objects internal state to indicate that the write
** transaction has been closed. This is quite safe, as the pager will have
** transitioned to the error state.
**
** This will release the write lock on the database file.  If there
** are no active cursors, it also releases the read lock.

** read it from this routine.
*/
SQLITE_PRIVATE void sqlite3BtreeGetMeta(Btree *p, int idx, u32 *pMeta){
  BtShared *pBt = p->pBt;

  sqlite3BtreeEnter(p);
  assert( p->inTrans>TRANS_NONE );
  assert( SQLITE_OK==querySharedCacheTableLock(p, SCHEMA_ROOT, READ_LOCK) );
  assert( pBt->pPage1 );
  assert( idx>=0 && idx<=15 );

  if( idx==BTREE_DATA_VERSION ){
    *pMeta = sqlite3PagerDataVersion(pBt->pPager) + p->iDataVersion;
  }else{
    *pMeta = get4byte(&pBt->pPage1->aData[36 + idx*4]);

  sqlite3BtreeLeave(p);
  return pBt->pSchema;
}

/*
** Return SQLITE_LOCKED_SHAREDCACHE if another user of the same shared 
** btree as the argument handle holds an exclusive lock on the 
** sqlite_schema table. Otherwise SQLITE_OK.
*/
SQLITE_PRIVATE int sqlite3BtreeSchemaLocked(Btree *p){
  int rc;
  assert( sqlite3_mutex_held(p->db->mutex) );
  sqlite3BtreeEnter(p);
  rc = querySharedCacheTableLock(p, SCHEMA_ROOT, READ_LOCK);
  assert( rc==SQLITE_OK || rc==SQLITE_LOCKED_SHAREDCACHE );
  sqlite3BtreeLeave(p);
  return rc;
}


#ifndef SQLITE_OMIT_SHARED_CACHE

  return rc;
}

/*
** A read or write transaction may or may not be active on database handle
** db. If a transaction is active, commit it. If there is a
** write-transaction spanning more than one database file, this routine
** takes care of the super-journal trickery.
*/
static int vdbeCommit(sqlite3 *db, Vdbe *p){
  int i;
  int nTrans = 0;  /* Number of databases with an active write-transaction
                   ** that are candidates for a two-phase commit using a
                   ** super-journal */
  int rc = SQLITE_OK;
  int needXcommit = 0;

#ifdef SQLITE_OMIT_VIRTUALTABLE
  /* With this option, sqlite3VtabSync() is defined to be simply 
  ** SQLITE_OK so p is not used. 
  */
  UNUSED_PARAMETER(p);
#endif

  /* Before doing anything else, call the xSync() callback for any
  ** virtual module tables written in this transaction. This has to
  ** be done before determining whether a super-journal file is 
  ** required, as an xSync() callback may add an attached database
  ** to the transaction.
  */
  rc = sqlite3VtabSync(db, p);

  /* This loop determines (a) if the commit hook should be invoked and
  ** (b) how many database files have open write transactions, not 
  ** including the temp database. (b) is important because if more than 
  ** one database file has an open write transaction, a super-journal
  ** file is required for an atomic commit.
  */ 
  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ 
    Btree *pBt = db->aDb[i].pBt;
    if( sqlite3BtreeIsInTrans(pBt) ){
      /* Whether or not a database might need a super-journal depends upon
      ** its journal mode (among other things).  This matrix determines which
      ** journal modes use a super-journal and which do not */
      static const u8 aMJNeeded[] = {
        /* DELETE   */  1,
        /* PERSIST   */ 1,
        /* OFF       */ 0,
        /* TRUNCATE  */ 1,
        /* MEMORY    */ 0,
        /* WAL       */ 0

    if( rc ){
      return SQLITE_CONSTRAINT_COMMITHOOK;
    }
  }

  /* The simple case - no more than one database file (not counting the
  ** TEMP database) has a transaction active.   There is no need for the
  ** super-journal.
  **
  ** If the return value of sqlite3BtreeGetFilename() is a zero length
  ** string, it means the main database is :memory: or a temp file.  In 
  ** that case we do not support atomic multi-file commits, so use the 
  ** simple case then too.
  */
  if( 0==sqlite3Strlen30(sqlite3BtreeGetFilename(db->aDb[0].pBt))

    }
    if( rc==SQLITE_OK ){
      sqlite3VtabCommit(db);
    }
  }

  /* The complex case - There is a multi-file write-transaction active.
  ** This requires a super-journal file to ensure the transaction is
  ** committed atomically.
  */
#ifndef SQLITE_OMIT_DISKIO
  else{
    sqlite3_vfs *pVfs = db->pVfs;
    char *zSuper = 0;   /* File-name for the super-journal */
    char const *zMainFile = sqlite3BtreeGetFilename(db->aDb[0].pBt);
    sqlite3_file *pSuperJrnl = 0;
    i64 offset = 0;
    int res;
    int retryCount = 0;
    int nMainFile;

    /* Select a super-journal file name */
    nMainFile = sqlite3Strlen30(zMainFile);
    zSuper = sqlite3MPrintf(db, "%.4c%s%.16c", 0,zMainFile,0);
    if( zSuper==0 ) return SQLITE_NOMEM_BKPT;
    zSuper += 4;
    do {
      u32 iRandom;
      if( retryCount ){
        if( retryCount>100 ){
          sqlite3_log(SQLITE_FULL, "MJ delete: %s", zSuper);
          sqlite3OsDelete(pVfs, zSuper, 0);
          break;
        }else if( retryCount==1 ){
          sqlite3_log(SQLITE_FULL, "MJ collide: %s", zSuper);
        }
      }
      retryCount++;
      sqlite3_randomness(sizeof(iRandom), &iRandom);
      sqlite3_snprintf(13, &zSuper[nMainFile], "-mj%06X9%02X",
                               (iRandom>>8)&0xffffff, iRandom&0xff);
      /* The antipenultimate character of the super-journal name must
      ** be "9" to avoid name collisions when using 8+3 filenames. */
      assert( zSuper[sqlite3Strlen30(zSuper)-3]=='9' );
      sqlite3FileSuffix3(zMainFile, zSuper);
      rc = sqlite3OsAccess(pVfs, zSuper, SQLITE_ACCESS_EXISTS, &res);
    }while( rc==SQLITE_OK && res );
    if( rc==SQLITE_OK ){
      /* Open the super-journal. */
      rc = sqlite3OsOpenMalloc(pVfs, zSuper, &pSuperJrnl, 
          SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
          SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_SUPER_JOURNAL, 0
      );
    }
    if( rc!=SQLITE_OK ){
      sqlite3DbFree(db, zSuper-4);
      return rc;
    }
 
    /* Write the name of each database file in the transaction into the new
    ** super-journal file. If an error occurs at this point close
    ** and delete the super-journal file. All the individual journal files
    ** still have 'null' as the super-journal pointer, so they will roll
    ** back independently if a failure occurs.
    */
    for(i=0; i<db->nDb; i++){
      Btree *pBt = db->aDb[i].pBt;
      if( sqlite3BtreeIsInTrans(pBt) ){
        char const *zFile = sqlite3BtreeGetJournalname(pBt);
        if( zFile==0 ){
          continue;  /* Ignore TEMP and :memory: databases */
        }
        assert( zFile[0]!=0 );
        rc = sqlite3OsWrite(pSuperJrnl, zFile, sqlite3Strlen30(zFile)+1,offset);
        offset += sqlite3Strlen30(zFile)+1;
        if( rc!=SQLITE_OK ){
          sqlite3OsCloseFree(pSuperJrnl);
          sqlite3OsDelete(pVfs, zSuper, 0);
          sqlite3DbFree(db, zSuper-4);
          return rc;
        }
      }
    }

    /* Sync the super-journal file. If the IOCAP_SEQUENTIAL device
    ** flag is set this is not required.
    */
    if( 0==(sqlite3OsDeviceCharacteristics(pSuperJrnl)&SQLITE_IOCAP_SEQUENTIAL)
     && SQLITE_OK!=(rc = sqlite3OsSync(pSuperJrnl, SQLITE_SYNC_NORMAL))
    ){
      sqlite3OsCloseFree(pSuperJrnl);
      sqlite3OsDelete(pVfs, zSuper, 0);
      sqlite3DbFree(db, zSuper-4);
      return rc;
    }

    /* Sync all the db files involved in the transaction. The same call
    ** sets the super-journal pointer in each individual journal. If
    ** an error occurs here, do not delete the super-journal file.
    **
    ** If the error occurs during the first call to
    ** sqlite3BtreeCommitPhaseOne(), then there is a chance that the
    ** super-journal file will be orphaned. But we cannot delete it,
    ** in case the super-journal file name was written into the journal
    ** file before the failure occurred.
    */
    for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ 
      Btree *pBt = db->aDb[i].pBt;
      if( pBt ){
        rc = sqlite3BtreeCommitPhaseOne(pBt, zSuper);
      }
    }
    sqlite3OsCloseFree(pSuperJrnl);
    assert( rc!=SQLITE_BUSY );
    if( rc!=SQLITE_OK ){
      sqlite3DbFree(db, zSuper-4);
      return rc;
    }

    /* Delete the super-journal file. This commits the transaction. After
    ** doing this the directory is synced again before any individual
    ** transaction files are deleted.
    */
    rc = sqlite3OsDelete(pVfs, zSuper, 1);
    sqlite3DbFree(db, zSuper-4);
    zSuper = 0;
    if( rc ){
      return rc;
    }

    /* All files and directories have already been synced, so the following
    ** calls to sqlite3BtreeCommitPhaseTwo() are only closing files and
    ** deleting or truncating journals. If something goes wrong while

  }else{
    /* Neither operand is NULL.  Do a comparison. */
    affinity = pOp->p5 & SQLITE_AFF_MASK;
    if( affinity>=SQLITE_AFF_NUMERIC ){
      if( (flags1 | flags3)&MEM_Str ){
        if( (flags1 & (MEM_Int|MEM_IntReal|MEM_Real|MEM_Str))==MEM_Str ){
          applyNumericAffinity(pIn1,0);
          testcase( flags3==pIn3->flags );
          flags3 = pIn3->flags;
        }
        if( (flags3 & (MEM_Int|MEM_IntReal|MEM_Real|MEM_Str))==MEM_Str ){
          applyNumericAffinity(pIn3,0);
        }
      }
      /* Handle the common case of integer comparison here, as an

      ** automatically created table with root-page 1 (an BLOB_INTKEY table).
      */
      if( (pCx->pKeyInfo = pKeyInfo = pOp->p4.pKeyInfo)!=0 ){
        assert( pOp->p4type==P4_KEYINFO );
        rc = sqlite3BtreeCreateTable(pCx->pBtx, (int*)&pCx->pgnoRoot,
                                     BTREE_BLOBKEY | pOp->p5); 
        if( rc==SQLITE_OK ){
          assert( pCx->pgnoRoot==SCHEMA_ROOT+1 );
          assert( pKeyInfo->db==db );
          assert( pKeyInfo->enc==ENC(db) );
          rc = sqlite3BtreeCursor(pCx->pBtx, pCx->pgnoRoot, BTREE_WRCSR,
                                  pKeyInfo, pCx->uc.pCursor);
        }
        pCx->isTable = 0;
      }else{
        pCx->pgnoRoot = SCHEMA_ROOT;
        rc = sqlite3BtreeCursor(pCx->pBtx, SCHEMA_ROOT, BTREE_WRCSR,
                                0, pCx->uc.pCursor);
        pCx->isTable = 1;
      }
    }
    pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
  }
  if( rc ) goto abort_due_to_error;

  db->nSqlExec--;
  if( rc ) goto abort_due_to_error;
  break;
}

/* Opcode: ParseSchema P1 * * P4 *
**
** Read and parse all entries from the schema table of database P1
** that match the WHERE clause P4.  If P4 is a NULL pointer, then the
** entire schema for P1 is reparsed.
**
** This opcode invokes the parser to create a new virtual machine,
** then runs the new virtual machine.  It is thus a re-entrant opcode.
*/
case OP_ParseSchema: {
  int iDb;
  const char *zSchema;
  char *zSql;
  InitData initData;

  /* Any prepared statement that invokes this opcode will hold mutexes
  ** on every btree.  This is a prerequisite for invoking 
  ** sqlite3InitCallback().
  */

    db->mDbFlags &= ~DBFLAG_SchemaKnownOk;
    rc = sqlite3InitOne(db, iDb, &p->zErrMsg, INITFLAG_AlterTable);
    db->mDbFlags |= DBFLAG_SchemaChange;
    p->expired = 0;
  }else
#endif
  {
    zSchema = DFLT_SCHEMA_TABLE;
    initData.db = db;
    initData.iDb = iDb;
    initData.pzErrMsg = &p->zErrMsg;
    initData.mInitFlags = 0;
    zSql = sqlite3MPrintf(db,
       "SELECT*FROM\"%w\".%s WHERE %s ORDER BY rowid",
       db->aDb[iDb].zDbSName, zSchema, pOp->p4.z);
    if( zSql==0 ){
      rc = SQLITE_NOMEM_BKPT;
    }else{
      assert( db->init.busy==0 );
      db->init.busy = 1;
      initData.rc = SQLITE_OK;
      initData.nInitRow = 0;
      assert( !db->mallocFailed );
      rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
      if( rc==SQLITE_OK ) rc = initData.rc;
      if( rc==SQLITE_OK && initData.nInitRow==0 ){
        /* The OP_ParseSchema opcode with a non-NULL P4 argument should parse
        ** at least one SQL statement. Any less than that indicates that
        ** the sqlite_schema table is corrupt. */
        rc = SQLITE_CORRUPT_BKPT;
      }
      sqlite3DbFreeNN(db, zSql);
      db->init.busy = 0;
    }
  }
  if( rc ){

**     sqlite3ExprIsConstantOrFunction()        pWalker->eCode==4 or 5
**
** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
** is found to not be a constant.
**
** The sqlite3ExprIsConstantOrFunction() is used for evaluating DEFAULT
** expressions in a CREATE TABLE statement.  The Walker.eCode value is 5
** when parsing an existing schema out of the sqlite_schema table and 4
** when processing a new CREATE TABLE statement.  A bound parameter raises
** an error for new statements, but is silently converted
** to NULL for existing schemas.  This allows sqlite_schema tables that 
** contain a bound parameter because they were generated by older versions
** of SQLite to be parsed by newer versions of SQLite without raising a
** malformed schema error.
*/
static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){

  /* If pWalker->eCode is 2 then any term of the expression that comes from

      }
      if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
        return WRC_Continue;
      }
      /* Fall through */
    case TK_IF_NULL_ROW:
    case TK_REGISTER:
    case TK_DOT:
      testcase( pExpr->op==TK_REGISTER );
      testcase( pExpr->op==TK_IF_NULL_ROW );
      testcase( pExpr->op==TK_DOT );
      pWalker->eCode = 0;
      return WRC_Abort;
    case TK_VARIABLE:
      if( pWalker->eCode==5 ){
        /* Silently convert bound parameters that appear inside of CREATE
        ** statements into a NULL when parsing the CREATE statement text out
        ** of the sqlite_schema table */
        pExpr->op = TK_NULL;
      }else if( pWalker->eCode==4 ){
        /* A bound parameter in a CREATE statement that originates from
        ** sqlite3_prepare() causes an error */
        pWalker->eCode = 0;
        return WRC_Abort;
      }

/*
** Walk an expression tree for the DEFAULT field of a column definition
** in a CREATE TABLE statement.  Return non-zero if the expression is 
** acceptable for use as a DEFAULT.  That is to say, return non-zero if
** the expression is constant or a function call with constant arguments.
** Return and 0 if there are any variables.
**
** isInit is true when parsing from sqlite_schema.  isInit is false when
** processing a new CREATE TABLE statement.  When isInit is true, parameters
** (such as ? or $abc) in the expression are converted into NULL.  When
** isInit is false, parameters raise an error.  Parameters should not be
** allowed in a CREATE TABLE statement, but some legacy versions of SQLite
** allowed it, so we need to support it when reading sqlite_schema for
** backwards compatibility.
**
** If isInit is true, set EP_FromDDL on every TK_FUNCTION node.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.

** An instance of the following structure is used by the tree walker
** to count references to table columns in the arguments of an 
** aggregate function, in order to implement the
** sqlite3FunctionThisSrc() routine.
*/
struct SrcCount {
  SrcList *pSrc;   /* One particular FROM clause in a nested query */
  int iSrcInner;   /* Smallest cursor number in this context */
  int nThis;       /* Number of references to columns in pSrcList */
  int nOther;      /* Number of references to columns in other FROM clauses */
};

/*
** xSelect callback for sqlite3FunctionUsesThisSrc(). If this is the first
** SELECT with a FROM clause encountered during this iteration, set
** SrcCount.iSrcInner to the cursor number of the leftmost object in
** the FROM cause.
*/
static int selectSrcCount(Walker *pWalker, Select *pSel){
  struct SrcCount *p = pWalker->u.pSrcCount;
  if( p->iSrcInner==0x7FFFFFFF && ALWAYS(pSel->pSrc) && pSel->pSrc->nSrc ){
    pWalker->u.pSrcCount->iSrcInner = pSel->pSrc->a[0].iCursor;
  }
  return WRC_Continue;
}

/*
** Count the number of references to columns.
*/
static int exprSrcCount(Walker *pWalker, Expr *pExpr){
  /* There was once a NEVER() on the second term on the grounds that
  ** sqlite3FunctionUsesThisSrc() was always called before 

    SrcList *pSrc = p->pSrc;
    int nSrc = pSrc ? pSrc->nSrc : 0;
    for(i=0; i<nSrc; i++){
      if( pExpr->iTable==pSrc->a[i].iCursor ) break;
    }
    if( i<nSrc ){
      p->nThis++;
    }else if( pExpr->iTable<p->iSrcInner ){
      /* In a well-formed parse tree (no name resolution errors),
      ** TK_COLUMN nodes with smaller Expr.iTable values are in an
      ** outer context.  Those are the only ones to count as "other" */
      p->nOther++;
    }
  }
  return WRC_Continue;

*/
SQLITE_PRIVATE int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){
  Walker w;
  struct SrcCount cnt;
  assert( pExpr->op==TK_AGG_FUNCTION );
  memset(&w, 0, sizeof(w));
  w.xExprCallback = exprSrcCount;
  w.xSelectCallback = selectSrcCount;
  w.u.pSrcCount = &cnt;
  cnt.pSrc = pSrcList;
  cnt.iSrcInner = (pSrcList&&pSrcList->nSrc)?pSrcList->a[0].iCursor:0x7FFFFFFF;
  cnt.nThis = 0;
  cnt.nOther = 0;
  sqlite3WalkExprList(&w, pExpr->x.pList);
#ifndef SQLITE_OMIT_WINDOWFUNC
  if( ExprHasProperty(pExpr, EP_WinFunc) ){
    sqlite3WalkExpr(&w, pExpr->y.pWin->pFilter);
  }

    AggInfo *pAggInfo = pExpr->pAggInfo;
    int iAgg = pExpr->iAgg;
    Parse *pParse = pWalker->pParse;
    sqlite3 *db = pParse->db;
    assert( pExpr->op==TK_AGG_COLUMN || pExpr->op==TK_AGG_FUNCTION );
    if( pExpr->op==TK_AGG_COLUMN ){
      assert( iAgg>=0 && iAgg<pAggInfo->nColumn );
      if( pAggInfo->aCol[iAgg].pCExpr==pExpr ){
        pExpr = sqlite3ExprDup(db, pExpr, 0);
        if( pExpr ){
          pAggInfo->aCol[iAgg].pCExpr = pExpr;
          pParse->pConstExpr = 
             sqlite3ExprListAppend(pParse, pParse->pConstExpr, pExpr);
        }
      }
    }else{
      assert( iAgg>=0 && iAgg<pAggInfo->nFunc );
      if( pAggInfo->aFunc[iAgg].pFExpr==pExpr ){
        pExpr = sqlite3ExprDup(db, pExpr, 0);
        if( pExpr ){
          pAggInfo->aFunc[iAgg].pFExpr = pExpr;
          pParse->pConstExpr = 
             sqlite3ExprListAppend(pParse, pParse->pConstExpr, pExpr);
        }
      }
    }
  }
  return WRC_Continue;

            ){
              pCol = &pAggInfo->aCol[k];
              pCol->pTab = pExpr->y.pTab;
              pCol->iTable = pExpr->iTable;
              pCol->iColumn = pExpr->iColumn;
              pCol->iMem = ++pParse->nMem;
              pCol->iSorterColumn = -1;
              pCol->pCExpr = pExpr;
              if( pAggInfo->pGroupBy ){
                int j, n;
                ExprList *pGB = pAggInfo->pGroupBy;
                struct ExprList_item *pTerm = pGB->a;
                n = pGB->nExpr;
                for(j=0; j<n; j++, pTerm++){
                  Expr *pE = pTerm->pExpr;

       && pWalker->walkerDepth==pExpr->op2
      ){
        /* Check to see if pExpr is a duplicate of another aggregate 
        ** function that is already in the pAggInfo structure
        */
        struct AggInfo_func *pItem = pAggInfo->aFunc;
        for(i=0; i<pAggInfo->nFunc; i++, pItem++){
          if( sqlite3ExprCompare(0, pItem->pFExpr, pExpr, -1)==0 ){
            break;
          }
        }
        if( i>=pAggInfo->nFunc ){
          /* pExpr is original.  Make a new entry in pAggInfo->aFunc[]
          */
          u8 enc = ENC(pParse->db);
          i = addAggInfoFunc(pParse->db, pAggInfo);
          if( i>=0 ){
            assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
            pItem = &pAggInfo->aFunc[i];
            pItem->pFExpr = pExpr;
            pItem->iMem = ++pParse->nMem;
            assert( !ExprHasProperty(pExpr, EP_IntValue) );
            pItem->pFunc = sqlite3FindFunction(pParse->db,
                   pExpr->u.zToken, 
                   pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0);
            if( pExpr->flags & EP_Distinct ){
              pItem->iDistinct = pParse->nTab++;

** called at the end of the generation of an ALTER TABLE ... RENAME ...
** statement to ensure that the operation has not rendered any schema
** objects unusable.
*/
static void renameTestSchema(Parse *pParse, const char *zDb, int bTemp){
  sqlite3NestedParse(pParse, 
      "SELECT 1 "
      "FROM \"%w\"." DFLT_SCHEMA_TABLE " "
      "WHERE name NOT LIKE 'sqliteX_%%' ESCAPE 'X'"
      " AND sql NOT LIKE 'create virtual%%'"
      " AND sqlite_rename_test(%Q, sql, type, name, %d)=NULL ",
      zDb,
      zDb, bTemp
  );

  if( bTemp==0 ){
    sqlite3NestedParse(pParse, 
        "SELECT 1 "
        "FROM temp." DFLT_SCHEMA_TABLE " "
        "WHERE name NOT LIKE 'sqliteX_%%' ESCAPE 'X'"
        " AND sql NOT LIKE 'create virtual%%'"
        " AND sqlite_rename_test(%Q, sql, type, name, 1)=NULL ",
        zDb 
    );
  }
}

/*
** Generate code to reload the schema for database iDb. And, if iDb!=1, for
** the temp database as well.

  /* figure out how many UTF-8 characters are in zName */
  zTabName = pTab->zName;
  nTabName = sqlite3Utf8CharLen(zTabName, -1);

  /* Rewrite all CREATE TABLE, INDEX, TRIGGER or VIEW statements in
  ** the schema to use the new table name.  */
  sqlite3NestedParse(pParse, 
      "UPDATE \"%w\"." DFLT_SCHEMA_TABLE " SET "
      "sql = sqlite_rename_table(%Q, type, name, sql, %Q, %Q, %d) "
      "WHERE (type!='index' OR tbl_name=%Q COLLATE nocase)"
      "AND   name NOT LIKE 'sqliteX_%%' ESCAPE 'X'"
      , zDb, zDb, zTabName, zName, (iDb==1), zTabName
  );

  /* Update the tbl_name and name columns of the sqlite_schema table
  ** as required.  */
  sqlite3NestedParse(pParse,
      "UPDATE %Q." DFLT_SCHEMA_TABLE " SET "
          "tbl_name = %Q, "
          "name = CASE "
            "WHEN type='table' THEN %Q "
            "WHEN name LIKE 'sqliteX_autoindex%%' ESCAPE 'X' "
            "     AND type='index' THEN "
             "'sqlite_autoindex_' || %Q || substr(name,%d+18) "
            "ELSE name END "
      "WHERE tbl_name=%Q COLLATE nocase AND "
          "(type='table' OR type='index' OR type='trigger');", 
      zDb,
      zName, zName, zName, 
      nTabName, zTabName
  );

#ifndef SQLITE_OMIT_AUTOINCREMENT
  /* If the sqlite_sequence table exists in this database, then update 
  ** it with the new table name.
  */
  if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){
    sqlite3NestedParse(pParse,
        "UPDATE \"%w\".sqlite_sequence set name = %Q WHERE name = %Q",
        zDb, zName, pTab->zName);
  }
#endif

  /* If the table being renamed is not itself part of the temp database,
  ** edit view and trigger definitions within the temp database 
  ** as required.  */
  if( iDb!=1 ){
    sqlite3NestedParse(pParse, 
        "UPDATE sqlite_temp_schema SET "
            "sql = sqlite_rename_table(%Q, type, name, sql, %Q, %Q, 1), "
            "tbl_name = "
              "CASE WHEN tbl_name=%Q COLLATE nocase AND "
              "          sqlite_rename_test(%Q, sql, type, name, 1) "
              "THEN %Q ELSE tbl_name END "
            "WHERE type IN ('view', 'trigger')"
        , zDb, zTabName, zName, zTabName, zDb, zName);

    char *zEnd = &zCol[pColDef->n-1];
    u32 savedDbFlags = db->mDbFlags;
    while( zEnd>zCol && (*zEnd==';' || sqlite3Isspace(*zEnd)) ){
      *zEnd-- = '\0';
    }
    db->mDbFlags |= DBFLAG_PreferBuiltin;
    sqlite3NestedParse(pParse, 
        "UPDATE \"%w\"." DFLT_SCHEMA_TABLE " SET "
          "sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "
        "WHERE type = 'table' AND name = %Q", 
      zDb, pNew->addColOffset, zCol, pNew->addColOffset+1,
      zTab
    );
    sqlite3DbFree(db, zCol);
    db->mDbFlags = savedDbFlags;
  }

  /* Make sure the schema version is at least 3.  But do not upgrade

  if( iCol==pTab->nCol ){
    sqlite3ErrorMsg(pParse, "no such column: \"%s\"", zOld);
    goto exit_rename_column;
  }

  /* Do the rename operation using a recursive UPDATE statement that
  ** uses the sqlite_rename_column() SQL function to compute the new
  ** CREATE statement text for the sqlite_schema table.
  */
  sqlite3MayAbort(pParse);
  zNew = sqlite3NameFromToken(db, pNew);
  if( !zNew ) goto exit_rename_column;
  assert( pNew->n>0 );
  bQuote = sqlite3Isquote(pNew->z[0]);
  sqlite3NestedParse(pParse, 
      "UPDATE \"%w\"." DFLT_SCHEMA_TABLE " SET "
      "sql = sqlite_rename_column(sql, type, name, %Q, %Q, %d, %Q, %d, %d) "
      "WHERE name NOT LIKE 'sqliteX_%%' ESCAPE 'X' "
      " AND (type != 'index' OR tbl_name = %Q)"
      " AND sql NOT LIKE 'create virtual%%'",
      zDb,
      zDb, pTab->zName, iCol, zNew, bQuote, iSchema==1,
      pTab->zName
  );

  sqlite3NestedParse(pParse, 
      "UPDATE temp." DFLT_SCHEMA_TABLE " SET "
      "sql = sqlite_rename_column(sql, type, name, %Q, %Q, %d, %Q, %d, 1) "
      "WHERE type IN ('trigger', 'view')",

      zDb, pTab->zName, iCol, zNew, bQuote
  );

  /* Drop and reload the database schema. */
  renameReloadSchema(pParse, iSchema);
  renameTestSchema(pParse, zDb, iSchema==1);

** code for the SQL statement given onto the end of the pParse context
** currently under construction.  When the parser is run recursively
** this way, the final OP_Halt is not appended and other initialization
** and finalization steps are omitted because those are handling by the
** outermost parser.
**
** Not everything is nestable.  This facility is designed to permit
** INSERT, UPDATE, and DELETE operations against the schema table.  Use
** care if you decide to try to use this routine for some other purposes.
*/
SQLITE_PRIVATE void sqlite3NestedParse(Parse *pParse, const char *zFormat, ...){
  va_list ap;
  char *zSql;
  char *zErrMsg = 0;
  sqlite3 *db = pParse->db;

      if( sqlite3StrICmp(zDatabase,"main")==0 ){
        i = 0;
      }else{
        return 0;
      }
    }
    p = sqlite3HashFind(&db->aDb[i].pSchema->tblHash, zName);
    if( p==0 && sqlite3StrNICmp(zName, "sqlite_", 7)==0 ){
      if( i==1 ){
        if( sqlite3StrICmp(zName+7, ALT_TEMP_SCHEMA_TABLE+7)==0
         || sqlite3StrICmp(zName+7, ALT_SCHEMA_TABLE+7)==0
         || sqlite3StrICmp(zName+7, DFLT_SCHEMA_TABLE+7)==0
        ){
          p = sqlite3HashFind(&db->aDb[1].pSchema->tblHash, 
                              DFLT_TEMP_SCHEMA_TABLE);
        }
      }else{
        if( sqlite3StrICmp(zName+7, ALT_SCHEMA_TABLE+7)==0 ){
          p = sqlite3HashFind(&db->aDb[i].pSchema->tblHash,
                              DFLT_SCHEMA_TABLE);
        }
      }
    }
  }else{
    /* Match against TEMP first */
    p = sqlite3HashFind(&db->aDb[1].pSchema->tblHash, zName);
    if( p ) return p;
    /* The main database is second */
    p = sqlite3HashFind(&db->aDb[0].pSchema->tblHash, zName);
    if( p ) return p;
    /* Attached databases are in order of attachment */
    for(i=2; i<db->nDb; i++){
      assert( sqlite3SchemaMutexHeld(db, i, 0) );
      p = sqlite3HashFind(&db->aDb[i].pSchema->tblHash, zName);
      if( p ) break;
    }
    if( p==0 && sqlite3StrNICmp(zName, "sqlite_", 7)==0 ){
      if( sqlite3StrICmp(zName+7, ALT_SCHEMA_TABLE+7)==0 ){
        p = sqlite3HashFind(&db->aDb[0].pSchema->tblHash, DFLT_SCHEMA_TABLE);
      }else if( sqlite3StrICmp(zName+7, ALT_TEMP_SCHEMA_TABLE+7)==0 ){
        p = sqlite3HashFind(&db->aDb[1].pSchema->tblHash, 
                            DFLT_TEMP_SCHEMA_TABLE);
      }
    }
  }
  return p;
}

/*
** Locate the in-memory structure that describes a particular database

  }else{
    zName = 0;
  }
  return zName;
}

/*
** Open the sqlite_schema table stored in database number iDb for
** writing. The table is opened using cursor 0.
*/
SQLITE_PRIVATE void sqlite3OpenSchemaTable(Parse *p, int iDb){
  Vdbe *v = sqlite3GetVdbe(p);
  sqlite3TableLock(p, iDb, SCHEMA_ROOT, 1, DFLT_SCHEMA_TABLE);
  sqlite3VdbeAddOp4Int(v, OP_OpenWrite, 0, SCHEMA_ROOT, iDb, 5);
  if( p->nTab==0 ){
    p->nTab = 1;
  }
}

/*
** Parameter zName points to a nul-terminated buffer containing the name

/*
** This routine is used to check if the UTF-8 string zName is a legal
** unqualified name for a new schema object (table, index, view or
** trigger). All names are legal except those that begin with the string
** "sqlite_" (in upper, lower or mixed case). This portion of the namespace
** is reserved for internal use.
**
** When parsing the sqlite_schema table, this routine also checks to
** make sure the "type", "name", and "tbl_name" columns are consistent
** with the SQL.
*/
SQLITE_PRIVATE int sqlite3CheckObjectName(
  Parse *pParse,            /* Parsing context */
  const char *zName,        /* Name of the object to check */
  const char *zType,        /* Type of this object */

  char *zName = 0; /* The name of the new table */
  sqlite3 *db = pParse->db;
  Vdbe *v;
  int iDb;         /* Database number to create the table in */
  Token *pName;    /* Unqualified name of the table to create */

  if( db->init.busy && db->init.newTnum==1 ){
    /* Special case:  Parsing the sqlite_schema or sqlite_temp_schema schema */
    iDb = db->init.iDb;
    zName = sqlite3DbStrDup(db, SCHEMA_TABLE(iDb));
    pName = pName1;
  }else{
    /* The common case */
    iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
    if( iDb<0 ) return;

  if( !pParse->nested && strcmp(zName, "sqlite_sequence")==0 ){
    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
    pTable->pSchema->pSeqTab = pTable;
  }
#endif

  /* Begin generating the code that will insert the table record into
  ** the schema table.  Note in particular that we must go ahead
  ** and allocate the record number for the table entry now.  Before any
  ** PRIMARY KEY or UNIQUE keywords are parsed.  Those keywords will cause
  ** indices to be created and the table record must come before the 
  ** indices.  Hence, the record number for the table must be allocated
  ** now.
  */
  if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){

    addr1 = sqlite3VdbeAddOp1(v, OP_If, reg3); VdbeCoverage(v);
    fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
                  1 : SQLITE_MAX_FILE_FORMAT;
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, fileFormat);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_TEXT_ENCODING, ENC(db));
    sqlite3VdbeJumpHere(v, addr1);

    /* This just creates a place-holder record in the sqlite_schema table.
    ** The record created does not contain anything yet.  It will be replaced
    ** by the real entry in code generated at sqlite3EndTable().
    **
    ** The rowid for the new entry is left in register pParse->regRowid.
    ** The root page number of the new table is left in reg pParse->regRoot.
    ** The rowid and root page number values are needed by the code that
    ** sqlite3EndTable will generate.
    */
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
    if( isView || isVirtual ){
      sqlite3VdbeAddOp2(v, OP_Integer, 0, reg2);
    }else
#endif
    {
      pParse->addrCrTab =
         sqlite3VdbeAddOp3(v, OP_CreateBtree, iDb, reg2, BTREE_INTKEY);
    }
    sqlite3OpenSchemaTable(pParse, iDb);
    sqlite3VdbeAddOp2(v, OP_NewRowid, 0, reg1);
    sqlite3VdbeAddOp4(v, OP_Blob, 6, reg3, 0, nullRow, P4_STATIC);
    sqlite3VdbeAddOp3(v, OP_Insert, 0, reg3, reg1);
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
    sqlite3VdbeAddOp0(v, OP_Close);
  }

** internal schema data structures and the generated VDBE code so that they
** are appropriate for a WITHOUT ROWID table instead of a rowid table.
** Changes include:
**
**     (1)  Set all columns of the PRIMARY KEY schema object to be NOT NULL.
**     (2)  Convert P3 parameter of the OP_CreateBtree from BTREE_INTKEY 
**          into BTREE_BLOBKEY.
**     (3)  Bypass the creation of the sqlite_schema table entry
**          for the PRIMARY KEY as the primary key index is now
**          identified by the sqlite_schema table entry of the table itself.
**     (4)  Set the Index.tnum of the PRIMARY KEY Index object in the
**          schema to the rootpage from the main table.
**     (5)  Add all table columns to the PRIMARY KEY Index object
**          so that the PRIMARY KEY is a covering index.  The surplus
**          columns are part of KeyInfo.nAllField and are not used for
**          sorting or lookup or uniqueness checks.
**     (6)  Replace the rowid tail on all automatically generated UNIQUE

    pPk->nKeyCol = j;
  }
  assert( pPk!=0 );
  pPk->isCovering = 1;
  if( !db->init.imposterTable ) pPk->uniqNotNull = 1;
  nPk = pPk->nColumn = pPk->nKeyCol;

  /* Bypass the creation of the PRIMARY KEY btree and the sqlite_schema
  ** table entry. This is only required if currently generating VDBE
  ** code for a CREATE TABLE (not when parsing one as part of reading
  ** a database schema).  */
  if( v && pPk->tnum>0 ){
    assert( db->init.busy==0 );
    sqlite3VdbeChangeOpcode(v, pPk->tnum, OP_Goto);
  }

** This routine is called to report the final ")" that terminates
** a CREATE TABLE statement.
**
** The table structure that other action routines have been building
** is added to the internal hash tables, assuming no errors have
** occurred.
**
** An entry for the table is made in the schema table on disk, unless
** this is a temporary table or db->init.busy==1.  When db->init.busy==1
** it means we are reading the sqlite_schema table because we just
** connected to the database or because the sqlite_schema table has
** recently changed, so the entry for this table already exists in
** the sqlite_schema table.  We do not want to create it again.
**
** If the pSelect argument is not NULL, it means that this routine
** was called to create a table generated from a 
** "CREATE TABLE ... AS SELECT ..." statement.  The column names of
** the new table will match the result set of the SELECT.
*/
SQLITE_PRIVATE void sqlite3EndTable(

  if( p==0 ) return;

  if( pSelect==0 && sqlite3ShadowTableName(db, p->zName) ){
    p->tabFlags |= TF_Shadow;
  }

  /* If the db->init.busy is 1 it means we are reading the SQL off the
  ** "sqlite_schema" or "sqlite_temp_schema" table on the disk.
  ** So do not write to the disk again.  Extract the root page number
  ** for the table from the db->init.newTnum field.  (The page number
  ** should have been put there by the sqliteOpenCb routine.)
  **
  ** If the root page number is 1, that means this is the sqlite_schema
  ** table itself.  So mark it read-only.
  */
  if( db->init.busy ){
    if( pSelect ){
      sqlite3ErrorMsg(pParse, "");
      return;
    }

  /* Estimate the average row size for the table and for all implied indices */
  estimateTableWidth(p);
  for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
    estimateIndexWidth(pIdx);
  }

  /* If not initializing, then create a record for the new table
  ** in the schema table of the database.
  **
  ** If this is a TEMPORARY table, write the entry into the auxiliary
  ** file instead of into the main database file.
  */
  if( !db->init.busy ){
    int n;
    Vdbe *v;

      if( pEnd2->z[0]!=';' ) n += pEnd2->n;
      zStmt = sqlite3MPrintf(db, 
          "CREATE %s %.*s", zType2, n, pParse->sNameToken.z
      );
    }

    /* A slot for the record has already been allocated in the 
    ** schema table.  We just need to update that slot with all
    ** the information we've collected.
    */
    sqlite3NestedParse(pParse,
      "UPDATE %Q." DFLT_SCHEMA_TABLE
      " SET type='%s', name=%Q, tbl_name=%Q, rootpage=#%d, sql=%Q"
      " WHERE rowid=#%d",
      db->aDb[iDb].zDbSName,
      zType,
      p->zName,
      p->zName,
      pParse->regRoot,
      zStmt,
      pParse->regRowid
    );

  n = (int)(sEnd.z - pBegin->z);
  assert( n>0 );
  z = pBegin->z;
  while( sqlite3Isspace(z[n-1]) ){ n--; }
  sEnd.z = &z[n-1];
  sEnd.n = 1;

  /* Use sqlite3EndTable() to add the view to the schema table */
  sqlite3EndTable(pParse, 0, &sEnd, 0, 0);

create_view_fail:
  sqlite3SelectDelete(db, pSelect);
  if( IN_RENAME_OBJECT ){
    sqlite3RenameExprlistUnmap(pParse, pCNames);
  }

    }
  }
}
#endif

/*
** Write code to erase the table with root-page iTable from database iDb.
** Also write code to modify the sqlite_schema table and internal schema
** if a root-page of another table is moved by the btree-layer whilst
** erasing iTable (this can happen with an auto-vacuum database).
*/ 
static void destroyRootPage(Parse *pParse, int iTable, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
  int r1 = sqlite3GetTempReg(pParse);
  if( iTable<2 ) sqlite3ErrorMsg(pParse, "corrupt schema");
  sqlite3VdbeAddOp3(v, OP_Destroy, iTable, r1, iDb);
  sqlite3MayAbort(pParse);
#ifndef SQLITE_OMIT_AUTOVACUUM
  /* OP_Destroy stores an in integer r1. If this integer
  ** is non-zero, then it is the root page number of a table moved to
  ** location iTable. The following code modifies the sqlite_schema table to
  ** reflect this.
  **
  ** 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." DFLT_SCHEMA_TABLE
     " SET rootpage=%d WHERE #%d AND rootpage=#%d",
     pParse->db->aDb[iDb].zDbSName, 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_schema tables and internal schema definitions
** in case a root-page belonging to another table is moved by the btree layer
** is also added (this can happen with an auto-vacuum database).
*/
static void destroyTable(Parse *pParse, Table *pTab){
  /* If the database may be auto-vacuum capable (if SQLITE_OMIT_AUTOVACUUM
  ** is not defined), then it is important to call OP_Destroy on the
  ** table and index root-pages in order, starting with the numerically 

#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( IsVirtual(pTab) ){
    sqlite3VdbeAddOp0(v, OP_VBegin);
  }
#endif

  /* Drop all triggers associated with the table being dropped. Code
  ** is generated to remove entries from sqlite_schema and/or
  ** sqlite_temp_schema if required.
  */
  pTrigger = sqlite3TriggerList(pParse, pTab);
  while( pTrigger ){
    assert( pTrigger->pSchema==pTab->pSchema || 
        pTrigger->pSchema==db->aDb[1].pSchema );
    sqlite3DropTriggerPtr(pParse, pTrigger);
    pTrigger = pTrigger->pNext;

    sqlite3NestedParse(pParse,
      "DELETE FROM %Q.sqlite_sequence WHERE name=%Q",
      pDb->zDbSName, pTab->zName
    );
  }
#endif

  /* Drop all entries in the schema table that refer to the
  ** table. The program name loops through the schema 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." DFLT_SCHEMA_TABLE
      " WHERE tbl_name=%Q and type!='trigger'",
      pDb->zDbSName, pTab->zName);
  if( !isView && !IsVirtual(pTab) ){
    destroyTable(pParse, pTab);
  }

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

  }
  if( !isView && pTab->pSelect ){
    sqlite3ErrorMsg(pParse, "use DROP VIEW to delete view %s", pTab->zName);
    goto exit_drop_table;
  }
#endif

  /* Generate code to remove the table from the schema table
  ** on disk.
  */
  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3BeginWriteOperation(pParse, 1, iDb);
    if( !isView ){
      sqlite3ClearStatTables(pParse, iDb, "tbl", pTab->zName);

  assert( pParse->nErr==0 );
  if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 
       && db->init.busy==0
       && pTblName!=0
#if SQLITE_USER_AUTHENTICATION
       && sqlite3UserAuthTable(pTab->zName)==0
#endif



  ){
    sqlite3ErrorMsg(pParse, "table %s may not be indexed", pTab->zName);
    goto exit_create_index;
  }
#ifndef SQLITE_OMIT_VIEW
  if( pTab->pSelect ){
    sqlite3ErrorMsg(pParse, "views may not be indexed");
    goto exit_create_index;

#endif

  /*
  ** Find the name of the index.  Make sure there is not already another
  ** index or table with the same name.  
  **
  ** Exception:  If we are reading the names of permanent indices from the
  ** sqlite_schema table (because some other process changed the schema) and
  ** one of the index names collides with the name of a temporary table or
  ** index, then we will continue to process this index.
  **
  ** If pName==0 it means that we are
  ** dealing with a primary key or UNIQUE constraint.  We have to invent our
  ** own name.
  */

      }
      db->mDbFlags |= DBFLAG_SchemaChange;
    }

    /* If this is the initial CREATE INDEX statement (or CREATE TABLE if the
    ** index is an implied index for a UNIQUE or PRIMARY KEY constraint) then
    ** emit code to allocate the index rootpage on disk and make an entry for
    ** the index in the sqlite_schema table and populate the index with
    ** content.  But, do not do this if we are simply reading the sqlite_schema
    ** table to parse the schema, or if this index is the PRIMARY KEY index
    ** of a WITHOUT ROWID table.
    **
    ** If pTblName==0 it means this index is generated as an implied PRIMARY KEY
    ** or UNIQUE index in a CREATE TABLE statement.  Since the table
    ** has just been created, it contains no data and the index initialization
    ** step can be skipped.

            onError==OE_None ? "" : " UNIQUE", n, pName->z);
      }else{
        /* An automatic index created by a PRIMARY KEY or UNIQUE constraint */
        /* zStmt = sqlite3MPrintf(""); */
        zStmt = 0;
      }

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

    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 schema table */
  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3BeginWriteOperation(pParse, 1, iDb);
    sqlite3NestedParse(pParse,
       "DELETE FROM %Q." DFLT_SCHEMA_TABLE " WHERE name=%Q AND type='index'",
       db->aDb[iDb].zDbSName, 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);
  }

/* Return true if table pTab is read-only.
**
** A table is read-only if any of the following are true:
**
**   1) It is a virtual table and no implementation of the xUpdate method
**      has been provided
**
**   2) It is a system table (i.e. sqlite_schema), this call is not
**      part of a nested parse and writable_schema pragma has not 
**      been specified
**
**   3) The table is a shadow table, the database connection is in
**      defensive mode, and the current sqlite3_prepare()
**      is for a top-level SQL statement.
*/

  */
  pItem = pSelect->pSrc->a;
  pSrc = sqlite3LocateTableItem(pParse, 0, pItem);
  if( pSrc==0 ){
    return 0;   /* FROM clause does not contain a real table */
  }
  if( pSrc->tnum==pDest->tnum && pSrc->pSchema==pDest->pSchema ){
    testcase( pSrc!=pDest ); /* Possible due to bad sqlite_schema.rootpage */
    return 0;   /* tab1 and tab2 may not be the same table */
  }
  if( HasRowid(pDest)!=HasRowid(pSrc) ){
    return 0;   /* source and destination must both be WITHOUT ROWID or not */
  }
#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( IsVirtual(pSrc) ){

#endif /* !defined(SQLITE_OMIT_LOAD_EXTENSION) */

/*
** The following object holds the list of automatically loaded
** extensions.
**
** This list is shared across threads.  The SQLITE_MUTEX_STATIC_MAIN
** mutex must be held while accessing this list.
*/
typedef struct sqlite3AutoExtList sqlite3AutoExtList;
static SQLITE_WSD struct sqlite3AutoExtList {
  u32 nExt;              /* Number of entries in aExt[] */          
  void (**aExt)(void);   /* Pointers to the extension init functions */
} sqlite3Autoext = { 0, 0 };

  if( rc ){
    return rc;
  }else
#endif
  {
    u32 i;
#if SQLITE_THREADSAFE
    sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
#endif
    wsdAutoextInit;
    sqlite3_mutex_enter(mutex);
    for(i=0; i<wsdAutoext.nExt; i++){
      if( wsdAutoext.aExt[i]==xInit ) break;
    }
    if( i==wsdAutoext.nExt ){

** Return 1 if xInit was found on the list and removed.  Return 0 if xInit
** was not on the list.
*/
SQLITE_API int sqlite3_cancel_auto_extension(
  void (*xInit)(void)
){
#if SQLITE_THREADSAFE
  sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
#endif
  int i;
  int n = 0;
  wsdAutoextInit;
  sqlite3_mutex_enter(mutex);
  for(i=(int)wsdAutoext.nExt-1; i>=0; i--){
    if( wsdAutoext.aExt[i]==xInit ){

*/
SQLITE_API void sqlite3_reset_auto_extension(void){
#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize()==SQLITE_OK )
#endif
  {
#if SQLITE_THREADSAFE
    sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
#endif
    wsdAutoextInit;
    sqlite3_mutex_enter(mutex);
    sqlite3_free(wsdAutoext.aExt);
    wsdAutoext.aExt = 0;
    wsdAutoext.nExt = 0;
    sqlite3_mutex_leave(mutex);

  if( wsdAutoext.nExt==0 ){
    /* Common case: early out without every having to acquire a mutex */
    return;
  }
  for(i=0; go; i++){
    char *zErrmsg;
#if SQLITE_THREADSAFE
    sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
#endif
#ifdef SQLITE_OMIT_LOAD_EXTENSION
    const sqlite3_api_routines *pThunk = 0;
#else
    const sqlite3_api_routines *pThunk = &sqlite3Apis;
#endif
    sqlite3_mutex_enter(mutex);

#ifndef SQLITE_OMIT_DEPRECATED
  int size;
#endif
  Db *pDb;
  char const *azArg[6];
  int meta[5];
  InitData initData;
  const char *zSchemaTabName;
  int openedTransaction = 0;
  int mask = ((db->mDbFlags & DBFLAG_EncodingFixed) | ~DBFLAG_EncodingFixed);

  assert( (db->mDbFlags & DBFLAG_SchemaKnownOk)==0 );
  assert( iDb>=0 && iDb<db->nDb );
  assert( db->aDb[iDb].pSchema );
  assert( sqlite3_mutex_held(db->mutex) );
  assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );

  db->init.busy = 1;

  /* Construct the in-memory representation schema tables (sqlite_schema or
  ** sqlite_temp_schema) by invoking the parser directly.  The appropriate
  ** table name will be inserted automatically by the parser so we can just
  ** use the abbreviation "x" here.  The parser will also automatically tag
  ** the schema table as read-only. */
  azArg[0] = "table";
  azArg[1] = zSchemaTabName = SCHEMA_TABLE(iDb);
  azArg[2] = azArg[1];
  azArg[3] = "1";
  azArg[4] = "CREATE TABLE x(type text,name text,tbl_name text,"
                            "rootpage int,sql text)";
  azArg[5] = 0;
  initData.db = db;
  initData.iDb = iDb;

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

  }
  if( rc==SQLITE_OK || (db->flags&SQLITE_NoSchemaError)){
    /* Black magic: If the SQLITE_NoSchemaError flag is set, then consider
    ** the schema loaded, even if errors occurred. In this situation the 
    ** current sqlite3_prepare() operation will fail, but the following one
    ** will attempt to compile the supplied statement against whatever subset
    ** of the schema was loaded before the error occurred. The primary
    ** purpose of this is to allow access to the sqlite_schema table
    ** even when its contents have been corrupted.
    */
    DbSetProperty(db, iDb, DB_SchemaLoaded);
    rc = SQLITE_OK;
  }

  /* Jump here for an error that occurs after successfully allocating

/*
** Rerun the compilation of a statement after a schema change.
**
** If the statement is successfully recompiled, return SQLITE_OK. Otherwise,
** if the statement cannot be recompiled because another connection has
** locked the sqlite3_schema table, return SQLITE_LOCKED. If any other error
** occurs, return SQLITE_SCHEMA.
*/
SQLITE_PRIVATE int sqlite3Reprepare(Vdbe *p){
  int rc;
  sqlite3_stmt *pNew;
  const char *zSql;
  sqlite3 *db;

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
*/
/* #include "sqliteInt.h" */















/*
** An instance of the following object is used to record information about
** how to process the DISTINCT keyword, to simplify passing that information
** into the selectInnerLoop() routine.
*/
typedef struct DistinctCtx DistinctCtx;

        pLimit = p->pLimit;
        p->pLimit = 0;
        uniondest.eDest = op;
        ExplainQueryPlan((pParse, 1, "%s USING TEMP B-TREE",
                          selectOpName(p->op)));
        rc = sqlite3Select(pParse, p, &uniondest);
        testcase( rc!=SQLITE_OK );


        assert( p->pOrderBy==0 );
        pDelete = p->pPrior;
        p->pPrior = pPrior;
        p->pOrderBy = 0;
        if( p->op==TK_UNION ){
          p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
        }
        sqlite3ExprDelete(db, p->pLimit);

    **   SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b;
    **   \                     \_____________ subquery __________/          /
    **    \_____________________ outer query ______________________________/
    **
    ** We look at every expression in the outer query and every place we see
    ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
    */
    if( pSub->pOrderBy && (pParent->selFlags & SF_NoopOrderBy)==0 ){
      /* At this point, any non-zero iOrderByCol values indicate that the
      ** ORDER BY column expression is identical to the iOrderByCol'th
      ** expression returned by SELECT statement pSub. Since these values
      ** do not necessarily correspond to columns in SELECT statement pParent,
      ** zero them before transfering the ORDER BY clause.
      **
      ** Not doing this may cause an error if a subsequent call to this

      pSub->pOrderBy = 0;
    }
    pWhere = pSub->pWhere;
    pSub->pWhere = 0;
    if( isLeftJoin>0 ){
      sqlite3SetJoinExpr(pWhere, iNewParent);
    }
    if( pWhere ){
      if( pParent->pWhere ){
        pParent->pWhere = sqlite3PExpr(pParse, TK_AND, pWhere, pParent->pWhere);
      }else{
        pParent->pWhere = pWhere;
      }
    }
    if( db->mallocFailed==0 ){
      SubstContext x;
      x.pParse = pParse;
      x.iTable = iParent;
      x.iNewTable = iNewParent;
      x.isLeftJoin = isLeftJoin;
      x.pEList = pSub->pEList;

  Select *pSubq,        /* The subquery whose WHERE clause is to be augmented */
  Expr *pWhere,         /* The WHERE clause of the outer query */
  int iCursor,          /* Cursor number of the subquery */
  int isLeftJoin        /* True if pSubq is the right term of a LEFT JOIN */
){
  Expr *pNew;
  int nChng = 0;
  Select *pSel;
  if( pWhere==0 ) return 0;
  if( pSubq->selFlags & SF_Recursive ) return 0;  /* restriction (2) */

#ifndef SQLITE_OMIT_WINDOWFUNC
  for(pSel=pSubq; pSel; pSel=pSel->pPrior){
    if( pSel->pWin ) return 0;    /* restriction (6) */
  }
#endif

#ifdef SQLITE_DEBUG
  /* Only the first term of a compound can have a WITH clause.  But make
  ** sure no other terms are marked SF_Recursive in case something changes
  ** in the future.
  */

  Token dummy;

  if( p->pPrior==0 ) return WRC_Continue;
  if( p->pOrderBy==0 ) return WRC_Continue;
  for(pX=p; pX && (pX->op==TK_ALL || pX->op==TK_SELECT); pX=pX->pPrior){}
  if( pX==0 ) return WRC_Continue;
  a = p->pOrderBy->a;
#ifndef SQLITE_OMIT_WINDOWFUNC
  /* If iOrderByCol is already non-zero, then it has already been matched
  ** to a result column of the SELECT statement. This occurs when the
  ** SELECT is rewritten for window-functions processing and then passed
  ** to sqlite3SelectPrep() and similar a second time. The rewriting done
  ** by this function is not required in this case. */
  if( a[0].u.x.iOrderByCol ) return WRC_Continue;
#endif
  for(i=p->pOrderBy->nExpr-1; i>=0; i--){
    if( a[i].pExpr->flags & EP_Collate ) break;
  }
  if( i<0 ) return WRC_Continue;

  /* If we reach this point, that means the transformation is required. */

    assert( pAggInfo->aFunc[i].iMem>=pAggInfo->mnReg
         && pAggInfo->aFunc[i].iMem<=pAggInfo->mxReg );
  }
#endif
  sqlite3VdbeAddOp3(v, OP_Null, 0, pAggInfo->mnReg, pAggInfo->mxReg);
  for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
    if( pFunc->iDistinct>=0 ){
      Expr *pE = pFunc->pFExpr;
      assert( !ExprHasProperty(pE, EP_xIsSelect) );
      if( pE->x.pList==0 || pE->x.pList->nExpr!=1 ){
        sqlite3ErrorMsg(pParse, "DISTINCT aggregates must have exactly one "
           "argument");
        pFunc->iDistinct = -1;
      }else{
        KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pE->x.pList,0,0);

** in the AggInfo structure.
*/
static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){
  Vdbe *v = pParse->pVdbe;
  int i;
  struct AggInfo_func *pF;
  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
    ExprList *pList = pF->pFExpr->x.pList;
    assert( !ExprHasProperty(pF->pFExpr, EP_xIsSelect) );
    sqlite3VdbeAddOp2(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0);
    sqlite3VdbeAppendP4(v, pF->pFunc, P4_FUNCDEF);
  }
}


/*

  struct AggInfo_col *pC;

  pAggInfo->directMode = 1;
  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
    int nArg;
    int addrNext = 0;
    int regAgg;
    ExprList *pList = pF->pFExpr->x.pList;
    assert( !ExprHasProperty(pF->pFExpr, EP_xIsSelect) );
    assert( !IsWindowFunc(pF->pFExpr) );
    if( ExprHasProperty(pF->pFExpr, EP_WinFunc) ){
      Expr *pFilter = pF->pFExpr->y.pWin->pFilter;
      if( pAggInfo->nAccumulator 
       && (pF->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL) 
      ){
        if( regHit==0 ) regHit = ++pParse->nMem;
        /* If this is the first row of the group (regAcc==0), clear the
        ** "magnet" register regHit so that the accumulator registers
        ** are populated if the FILTER clause jumps over the the 

  if( regHit==0 && pAggInfo->nAccumulator ){
    regHit = regAcc;
  }
  if( regHit ){
    addrHitTest = sqlite3VdbeAddOp1(v, OP_If, regHit); VdbeCoverage(v);
  }
  for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
    sqlite3ExprCode(pParse, pC->pCExpr, pC->iMem);
  }

  pAggInfo->directMode = 0;
  if( addrHitTest ){
    sqlite3VdbeJumpHereOrPopInst(v, addrHitTest);
  }
}

           pDest->eDest==SRT_Queue  || pDest->eDest==SRT_DistFifo ||
           pDest->eDest==SRT_DistQueue || pDest->eDest==SRT_Fifo);
    /* If ORDER BY makes no difference in the output then neither does
    ** DISTINCT so it can be removed too. */
    sqlite3ExprListDelete(db, p->pOrderBy);
    p->pOrderBy = 0;
    p->selFlags &= ~SF_Distinct;
    p->selFlags |= SF_NoopOrderBy;
  }
  sqlite3SelectPrep(pParse, p, 0);
  if( pParse->nErr || db->mallocFailed ){
    goto select_end;
  }
  assert( p->pEList!=0 );
#if SELECTTRACE_ENABLED

#endif
#endif /* SQLITE_OMIT_WINDOWFUNC */
  pTabList = p->pSrc;
  isAgg = (p->selFlags & SF_Aggregate)!=0;
  memset(&sSort, 0, sizeof(sSort));
  sSort.pOrderBy = p->pOrderBy;

  /* Try to do various optimizations (flattening subqueries, and strength
  ** reduction of join operators) in the FROM clause up into the main query
  */
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
  for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
    struct SrcList_item *pItem = &pTabList->a[i];
    Select *pSub = pItem->pSelect;
    Table *pTab = pItem->pTab;

    /* The expander should have already created transient Table objects
    ** even for FROM clause elements such as subqueries that do not correspond
    ** to a real table */
    assert( pTab!=0 );

    /* Convert LEFT JOIN into JOIN if there are terms of the right table
    ** of the LEFT JOIN used in the WHERE clause.
    */
    if( (pItem->fg.jointype & JT_LEFT)!=0
     && sqlite3ExprImpliesNonNullRow(p->pWhere, pItem->iCursor)
     && OptimizationEnabled(db, SQLITE_SimplifyJoin)

  }

  if( !isAgg && pGroupBy==0 ){
    /* No aggregate functions and no GROUP BY clause */
    u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0)
                   | (p->selFlags & SF_FixedLimit);
#ifndef SQLITE_OMIT_WINDOWFUNC
    Window *pWin = p->pWin;      /* Main window object (or NULL) */
    if( pWin ){
      sqlite3WindowCodeInit(pParse, p);
    }
#endif
    assert( WHERE_USE_LIMIT==SF_FixedLimit );

    */
    pAggInfo = sqlite3DbMallocZero(db, sizeof(*pAggInfo) );
    if( pAggInfo==0 ){
      goto select_end;
    }
    pAggInfo->pNext = pParse->pAggList;
    pParse->pAggList = pAggInfo;
    pAggInfo->selId = p->selId;
    memset(&sNC, 0, sizeof(sNC));
    sNC.pParse = pParse;
    sNC.pSrcList = pTabList;
    sNC.uNC.pAggInfo = pAggInfo;
    VVA_ONLY( sNC.ncFlags = NC_UAggInfo; )
    pAggInfo->mnReg = pParse->nMem+1;
    pAggInfo->nSortingColumn = pGroupBy ? pGroupBy->nExpr : 0;

        havingToWhere(pParse, p);
        pWhere = p->pWhere;
      }
      sqlite3ExprAnalyzeAggregates(&sNC, pHaving);
    }
    pAggInfo->nAccumulator = pAggInfo->nColumn;
    if( p->pGroupBy==0 && p->pHaving==0 && pAggInfo->nFunc==1 ){
      minMaxFlag = minMaxQuery(db, pAggInfo->aFunc[0].pFExpr, &pMinMaxOrderBy);
    }else{
      minMaxFlag = WHERE_ORDERBY_NORMAL;
    }
    for(i=0; i<pAggInfo->nFunc; i++){
      Expr *pExpr = pAggInfo->aFunc[i].pFExpr;
      assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
      sNC.ncFlags |= NC_InAggFunc;
      sqlite3ExprAnalyzeAggList(&sNC, pExpr->x.pList);
#ifndef SQLITE_OMIT_WINDOWFUNC
      assert( !IsWindowFunc(pExpr) );
      if( ExprHasProperty(pExpr, EP_WinFunc) ){
        sqlite3ExprAnalyzeAggregates(&sNC, pExpr->y.pWin->pFilter);

    if( sqlite3SelectTrace & 0x400 ){
      int ii;
      SELECTTRACE(0x400,pParse,p,("After aggregate analysis %p:\n", pAggInfo));
      sqlite3TreeViewSelect(0, p, 0);
      for(ii=0; ii<pAggInfo->nColumn; ii++){
        sqlite3DebugPrintf("agg-column[%d] iMem=%d\n",
            ii, pAggInfo->aCol[ii].iMem);
        sqlite3TreeViewExpr(0, pAggInfo->aCol[ii].pCExpr, 0);
      }
      for(ii=0; ii<pAggInfo->nFunc; ii++){
        sqlite3DebugPrintf("agg-func[%d]: iMem=%d\n",
            ii, pAggInfo->aFunc[ii].iMem);
        sqlite3TreeViewExpr(0, pAggInfo->aFunc[ii].pFExpr, 0);
      }
    }
#endif


    /* Processing for aggregates with GROUP BY is very different and
    ** much more complex than aggregates without a GROUP BY.

        ** that the accumulator registers are (a) updated only once if
        ** there are no min() or max functions or (b) always updated for the
        ** first row visited by the aggregate, so that they are updated at
        ** least once even if the FILTER clause means the min() or max() 
        ** function visits zero rows.  */
        if( pAggInfo->nAccumulator ){
          for(i=0; i<pAggInfo->nFunc; i++){
            if( ExprHasProperty(pAggInfo->aFunc[i].pFExpr, EP_WinFunc) ){
              continue;
            }
            if( pAggInfo->aFunc[i].pFunc->funcFlags&SQLITE_FUNC_NEEDCOLL ){
              break;
            }
          }
          if( i==pAggInfo->nFunc ){

  /* Control jumps to here if an error is encountered above, or upon
  ** successful coding of the SELECT.
  */
select_end:
  sqlite3ExprListDelete(db, pMinMaxOrderBy);
#ifdef SQLITE_DEBUG
  if( pAggInfo && !db->mallocFailed ){
    for(i=0; i<pAggInfo->nColumn; i++){
      Expr *pExpr = pAggInfo->aCol[i].pCExpr;
      assert( pExpr!=0 || db->mallocFailed );
      if( pExpr==0 ) continue;
      assert( pExpr->pAggInfo==pAggInfo );
      assert( pExpr->iAgg==i );
    }
    for(i=0; i<pAggInfo->nFunc; i++){
      Expr *pExpr = pAggInfo->aFunc[i].pFExpr;
      assert( pExpr!=0 || db->mallocFailed );
      if( pExpr==0 ) continue;
      assert( pExpr->pAggInfo==pAggInfo );
      assert( pExpr->iAgg==i );
    }
  }
#endif

  /* A long-standing parser bug is that this syntax was allowed:
  **
  **    CREATE TRIGGER attached.demo AFTER INSERT ON attached.tab ....
  **                                                 ^^^^^^^^
  **
  ** To maintain backwards compatibility, ignore the database
  ** name on pTableName if we are reparsing out of the schema table
  */
  if( db->init.busy && iDb!=1 ){
    sqlite3DbFree(db, pTableName->a[0].zDatabase);
    pTableName->a[0].zDatabase = 0;
  }

  /* If the trigger name was unqualified, and the table is a temp table,

    assert( !db->init.busy );
    pParse->pNewTrigger = pTrig;
    pTrig = 0;
  }else
#endif

  /* if we are not initializing,
  ** build the sqlite_schema entry
  */
  if( !db->init.busy ){
    Vdbe *v;
    char *z;

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

  }
#endif

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

/*

** If the former, then all row-records are guaranteed to include a value
** for the column and the P4 value is not required.
**
** Column definitions created by an ALTER TABLE command may only have 
** literal default values specified: a number, null or a string. (If a more
** complicated default expression value was provided, it is evaluated 
** when the ALTER TABLE is executed and one of the literal values written
** into the sqlite_schema table.)
**
** Therefore, the P4 parameter is only required if the default value for
** the column is a literal number, string or null. The sqlite3ValueFromExpr()
** function is capable of transforming these types of expressions into
** sqlite3_value objects.
**
** If column as REAL affinity and the table is an ordinary b-tree table

  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
  if( rc!=SQLITE_OK ) return rc;
  while( SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){
    const char *zSubSql = (const char*)sqlite3_column_text(pStmt,0);
    assert( sqlite3_strnicmp(zSql,"SELECT",6)==0 );
    /* The secondary SQL must be one of CREATE TABLE, CREATE INDEX,
    ** or INSERT.  Historically there have been attacks that first
    ** corrupt the sqlite_schema.sql field with other kinds of statements
    ** then run VACUUM to get those statements to execute at inappropriate
    ** times. */
    if( zSubSql
     && (strncmp(zSubSql,"CRE",3)==0 || strncmp(zSubSql,"INS",3)==0)
    ){
      rc = execSql(db, pzErrMsg, zSubSql);
      if( rc!=SQLITE_OK ) break;

#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_schema"
      " 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_schema"
      " 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_schema "
      "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 schema table.
  */
  rc = execSqlF(db, pzErrMsg,
      "INSERT INTO vacuum_db.sqlite_schema"
      " SELECT*FROM \"%w\".sqlite_schema"
      " 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 

  pParse->sNameToken.n = (int)(
      &pModuleName->z[pModuleName->n] - pParse->sNameToken.z
  );

#ifndef SQLITE_OMIT_AUTHORIZATION
  /* Creating a virtual table invokes the authorization callback twice.
  ** The first invocation, to obtain permission to INSERT a row into the
  ** sqlite_schema table, has already been made by sqlite3StartTable().
  ** The second call, to obtain permission to create the table, is made now.
  */
  if( pTable->azModuleArg ){
    int iDb = sqlite3SchemaToIndex(db, pTable->pSchema);
    assert( iDb>=0 ); /* The database the table is being created in */
    sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName, 
            pTable->azModuleArg[0], pParse->db->aDb[iDb].zDbSName);

  if( pTab==0 ) return;
  addArgumentToVtab(pParse);
  pParse->sArg.z = 0;
  if( pTab->nModuleArg<1 ) return;
  
  /* If the CREATE VIRTUAL TABLE statement is being entered for the
  ** first time (in other words if the virtual table is actually being
  ** created now instead of just being read out of sqlite_schema) then
  ** do additional initialization work and store the statement text
  ** in the sqlite_schema table.
  */
  if( !db->init.busy ){
    char *zStmt;
    char *zWhere;
    int iDb;
    int iReg;
    Vdbe *v;

    sqlite3MayAbort(pParse);

    /* Compute the complete text of the CREATE VIRTUAL TABLE statement */
    if( pEnd ){
      pParse->sNameToken.n = (int)(pEnd->z - pParse->sNameToken.z) + pEnd->n;
    }
    zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken);

    /* A slot for the record has already been allocated in the 
    ** schema table.  We just need to update that slot with all
    ** the information we've collected.  
    **
    ** The VM register number pParse->regRowid holds the rowid of an
    ** entry in the sqlite_schema table tht was created for this vtab
    ** by sqlite3StartTable().
    */
    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
    sqlite3NestedParse(pParse,
      "UPDATE %Q." DFLT_SCHEMA_TABLE " "
         "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
       "WHERE rowid=#%d",
      db->aDb[iDb].zDbSName,
      pTab->zName,
      pTab->zName,
      zStmt,
      pParse->regRowid
    );
    v = sqlite3GetVdbe(pParse);
    sqlite3ChangeCookie(pParse, iDb);

    sqlite3VdbeAddOp0(v, OP_Expire);
    zWhere = sqlite3MPrintf(db, "name=%Q AND sql=%Q", pTab->zName, zStmt);
    sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere);
    sqlite3DbFree(db, zStmt);

    iReg = ++pParse->nMem;
    sqlite3VdbeLoadString(v, iReg, pTab->zName);
    sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg);
  }

  /* If we are rereading the sqlite_schema table create the in-memory
  ** record of the table. The xConnect() method is not called until
  ** the first time the virtual table is used in an SQL statement. This
  ** allows a schema that contains virtual tables to be loaded before
  ** the required virtual table implementations are registered.  */
  else {
    Table *pOld;
    Schema *pSchema = pTab->pSchema;

    SrcList *pSrc = p->pSrc;
    Expr *pWhere = p->pWhere;
    ExprList *pGroupBy = p->pGroupBy;
    Expr *pHaving = p->pHaving;
    ExprList *pSort = 0;

    ExprList *pSublist = 0;       /* Expression list for sub-query */
    Window *pMWin = p->pWin;      /* Main window object */
    Window *pWin;                 /* Window object iterator */
    Table *pTab;
    Walker w;

    u32 selFlags = p->selFlags;

    pTab = sqlite3DbMallocZero(db, sizeof(Table));

        sqlite3Expr(db, TK_INTEGER, "0")
      );
    }

    pSub = sqlite3SelectNew(
        pParse, pSublist, pSrc, pWhere, pGroupBy, pHaving, pSort, 0, 0
    );
    SELECTTRACE(1,pParse,pSub,
       ("New window-function subquery in FROM clause of (%u/%p)\n",
       p->selId, p));
    p->pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
    if( p->pSrc ){
      Table *pTab2;
      p->pSrc->a[0].pSelect = pSub;
      sqlite3SrcListAssignCursors(pParse, p->pSrc);
      pSub->selFlags |= SF_Expanded;
      pTab2 = sqlite3ResultSetOfSelect(pParse, pSub, SQLITE_AFF_NONE);

SQLITE_PRIVATE int sqlite3IcuInit(sqlite3 *db);

#if 0
}  /* extern "C" */
#endif  /* __cplusplus */


/************** End of sqliteicu.h *******************************************/
/************** Continuing where we left off in main.c ***********************/
#endif

/*
** This is an extension initializer that is a no-op and always
** succeeds, except that it fails if the fault-simulation is set

**    *  Calls to this routine from Y must block until the outer-most
**       call by X completes.
**
**    *  Recursive calls to this routine from thread X return immediately
**       without blocking.
*/
SQLITE_API int sqlite3_initialize(void){
  MUTEX_LOGIC( sqlite3_mutex *pMainMtx; )      /* The main static mutex */
  int rc;                                      /* Result code */
#ifdef SQLITE_EXTRA_INIT
  int bRunExtraInit = 0;                       /* Extra initialization needed */
#endif

#ifdef SQLITE_OMIT_WSD
  rc = sqlite3_wsd_init(4096, 24);

  ** The mutex subsystem must take care of serializing its own
  ** initialization.
  */
  rc = sqlite3MutexInit();
  if( rc ) return rc;

  /* Initialize the malloc() system and the recursive pInitMutex mutex.
  ** This operation is protected by the STATIC_MAIN mutex.  Note that
  ** MutexAlloc() is called for a static mutex prior to initializing the
  ** malloc subsystem - this implies that the allocation of a static
  ** mutex must not require support from the malloc subsystem.
  */
  MUTEX_LOGIC( pMainMtx = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN); )
  sqlite3_mutex_enter(pMainMtx);
  sqlite3GlobalConfig.isMutexInit = 1;
  if( !sqlite3GlobalConfig.isMallocInit ){
    rc = sqlite3MallocInit();
  }
  if( rc==SQLITE_OK ){
    sqlite3GlobalConfig.isMallocInit = 1;
    if( !sqlite3GlobalConfig.pInitMutex ){
      sqlite3GlobalConfig.pInitMutex =
           sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
      if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
        rc = SQLITE_NOMEM_BKPT;
      }
    }
  }
  if( rc==SQLITE_OK ){
    sqlite3GlobalConfig.nRefInitMutex++;
  }
  sqlite3_mutex_leave(pMainMtx);

  /* If rc is not SQLITE_OK at this point, then either the malloc
  ** subsystem could not be initialized or the system failed to allocate
  ** the pInitMutex mutex. Return an error in either case.  */
  if( rc!=SQLITE_OK ){
    return rc;
  }

    sqlite3GlobalConfig.inProgress = 0;
  }
  sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);

  /* Go back under the static mutex and clean up the recursive
  ** mutex to prevent a resource leak.
  */
  sqlite3_mutex_enter(pMainMtx);
  sqlite3GlobalConfig.nRefInitMutex--;
  if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
    assert( sqlite3GlobalConfig.nRefInitMutex==0 );
    sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
    sqlite3GlobalConfig.pInitMutex = 0;
  }
  sqlite3_mutex_leave(pMainMtx);

  /* The following is just a sanity check to make sure SQLite has
  ** been compiled correctly.  It is important to run this code, but
  ** we don't want to run it too often and soak up CPU cycles for no
  ** reason.  So we run it once during initialization.
  */
#ifndef NDEBUG

               SQLITE_OPEN_EXCLUSIVE |
               SQLITE_OPEN_MAIN_DB |
               SQLITE_OPEN_TEMP_DB | 
               SQLITE_OPEN_TRANSIENT_DB | 
               SQLITE_OPEN_MAIN_JOURNAL | 
               SQLITE_OPEN_TEMP_JOURNAL | 
               SQLITE_OPEN_SUBJOURNAL | 
               SQLITE_OPEN_SUPER_JOURNAL |
               SQLITE_OPEN_NOMUTEX |
               SQLITE_OPEN_FULLMUTEX |
               SQLITE_OPEN_WAL
             );

  /* Allocate the sqlite data structure */
  db = sqlite3MallocZero( sizeof(sqlite3) );

      sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
      break;
    }

    /*   sqlite3_test_control(SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS, int);
    **
    ** Set or clear a flag that causes SQLite to verify that type, name,
    ** and tbl_name fields of the sqlite_schema table.  This is normally
    ** on, but it is sometimes useful to turn it off for testing.
    */
    case SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS: {
      sqlite3GlobalConfig.bExtraSchemaChecks = va_arg(ap, int);
      break;
    }

**   sqlite3ConnectionBlocked()
**   sqlite3ConnectionUnlocked()
**   sqlite3ConnectionClosed()
**   sqlite3_unlock_notify()
*/

#define assertMutexHeld() \
  assert( sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN)) )

/*
** Head of a linked list of all sqlite3 objects created by this process
** for which either sqlite3.pBlockingConnection or sqlite3.pUnlockConnection
** is not NULL. This variable may only accessed while the STATIC_MAIN
** mutex is held.
*/
static sqlite3 *SQLITE_WSD sqlite3BlockedList = 0;

#ifndef NDEBUG
/*
** This function is a complex assert() that verifies the following 

    pp=&(*pp)->pNextBlocked
  );
  db->pNextBlocked = *pp;
  *pp = db;
}

/*
** Obtain the STATIC_MAIN mutex.
*/
static void enterMutex(void){
  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN));
  checkListProperties(0);
}

/*
** Release the STATIC_MAIN mutex.
*/
static void leaveMutex(void){
  assertMutexHeld();
  checkListProperties(0);
  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN));
}

/*
** Register an unlock-notify callback.
**
** This is called after connection "db" has attempted some operation
** but has received an SQLITE_LOCKED error because another connection

  int nArg = 0;                            /* Number of entries in aArg[] */
  sqlite3 **pp;                            /* Iterator variable */
  void **aArg;               /* Arguments to the unlock callback */
  void **aDyn = 0;           /* Dynamically allocated space for aArg[] */
  void *aStatic[16];         /* Starter space for aArg[].  No malloc required */

  aArg = aStatic;
  enterMutex();         /* Enter STATIC_MAIN mutex */

  /* This loop runs once for each entry in the blocked-connections list. */
  for(pp=&sqlite3BlockedList; *pp; /* no-op */ ){
    sqlite3 *p = *pp;

    /* Step 1. */
    if( p->pBlockingConnection==db ){

    }
  }

  if( nArg!=0 ){
    xUnlockNotify(aArg, nArg);
  }
  sqlite3_free(aDyn);
  leaveMutex();         /* Leave STATIC_MAIN mutex */
}

/*
** This is called when the database connection passed as an argument is 
** being closed. The connection is removed from the blocked list.
*/
SQLITE_PRIVATE void sqlite3ConnectionClosed(sqlite3 *db){

      ** POS_END (0) or POS_COLUMN (1). The following block merges the two lists
      ** and writes the results to buffer p. p is left pointing to the byte
      ** after the list written. No terminator (POS_END or POS_COLUMN) is
      ** written to the output.
      */
      fts3GetDeltaVarint(&p1, &i1);
      fts3GetDeltaVarint(&p2, &i2);
      if( i1<2 || i2<2 ){
        break;
      }
      do {
        fts3PutDeltaVarint(&p, &iPrev, (i1<i2) ? i1 : i2); 
        iPrev -= 2;
        if( i1==i2 ){
          fts3ReadNextPos(&p1, &i1);
          fts3ReadNextPos(&p2, &i2);
        }else if( i1<i2 ){

  char *p2 = *pp2;
  int iCol1 = 0;
  int iCol2 = 0;

  /* Never set both isSaveLeft and isExact for the same invocation. */
  assert( isSaveLeft==0 || isExact==0 );

  assert_fts3_nc( p!=0 && *p1!=0 && *p2!=0 );
  if( *p1==POS_COLUMN ){ 
    p1++;
    p1 += fts3GetVarint32(p1, &iCol1);
  }
  if( *p2==POS_COLUMN ){ 
    p2++;
    p2 += fts3GetVarint32(p2, &iCol2);

  sqlite3_int64 *piDocid,         /* IN/OUT: Docid pointer */
  u8 *pbEof                       /* OUT: End-of-file flag */
){
  char *p = *ppIter;

  assert( nDoclist>0 );
  assert( *pbEof==0 );
  assert_fts3_nc( p || *piDocid==0 );
  assert( !p || (p>=aDoclist && p<=&aDoclist[nDoclist]) );

  if( p==0 ){
    p = aDoclist;
    p += sqlite3Fts3GetVarint(p, piDocid);
  }else{
    fts3PoslistCopy(0, &p);

** the phrase object passed as the fifth argument according to a NEAR
** condition. For example:
**
**     abc NEAR/5 "def ghi"
**
** Parameter nNear is passed the NEAR distance of the expression (5 in
** the example above). When this function is called, *paPoslist points to
** the position list, and *pnToken is the number of phrase tokens in the
** phrase on the other side of the NEAR operator to pPhrase. For example,
** if pPhrase refers to the "def ghi" phrase, then *paPoslist points to
** the position list associated with phrase "abc".
**
** All positions in the pPhrase position list that are not sufficiently
** close to a position in the *paPoslist position list are removed. If this
** leaves 0 positions, zero is returned. Otherwise, non-zero.

          }
          *pRc = fts3EvalDeferredPhrase(pCsr, pPhrase);
          bHit = (pPhrase->doclist.pList!=0);
          pExpr->iDocid = pCsr->iPrevId;
        }else
#endif
        {
          bHit = ( 
              pExpr->bEof==0 && pExpr->iDocid==pCsr->iPrevId
           && pExpr->pPhrase->doclist.nList>0
          );
        }
        break;
      }
    }
  }
  return bHit;
}

    }else{
      sqlite3_free(p);
      aCoord[0].f = mnX;
      aCoord[1].f = mxX;
      aCoord[2].f = mnY;
      aCoord[3].f = mxY;
    }
  }else{
    memset(aCoord, 0, sizeof(RtreeCoord)*4);
  }
  return pOut;
}

/*
** Implementation of the geopoly_bbox(X) SQL function.
*/

static int rbuObjIterFirst(sqlite3rbu *p, RbuObjIter *pIter){
  int rc;
  memset(pIter, 0, sizeof(RbuObjIter));

  rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pTblIter, &p->zErrmsg, 
    sqlite3_mprintf(
      "SELECT rbu_target_name(name, type='view') AS target, name "
      "FROM sqlite_schema "
      "WHERE type IN ('table', 'view') AND target IS NOT NULL "
      " %s "
      "ORDER BY name"
  , rbuIsVacuum(p) ? "AND rootpage!=0 AND rootpage IS NOT NULL" : ""));

  if( rc==SQLITE_OK ){
    rc = prepareAndCollectError(p->dbMain, &pIter->pIdxIter, &p->zErrmsg,
        "SELECT name, rootpage, sql IS NULL OR substr(8, 6)=='UNIQUE' "
        "  FROM main.sqlite_schema "
        "  WHERE type='index' AND tbl_name = ?"
    );
  }

  pIter->bCleanup = 1;
  p->rc = rc;
  return rbuObjIterNext(p, pIter);

**   (i.e. unless *peType is set to 3), then *piPk is set to zero. Or,
**   if the table does have an external primary key index, then *piPk
**   is set to the root page number of the primary key index before
**   returning.
**
** ALGORITHM:
**
**   if( no entry exists in sqlite_schema ){
**     return RBU_PK_NOTABLE
**   }else if( sql for the entry starts with "CREATE VIRTUAL" ){
**     return RBU_PK_VTAB
**   }else if( "PRAGMA index_list()" for the table contains a "pk" index ){
**     if( the index that is the pk exists in sqlite_schema ){
**       *piPK = rootpage of that index.
**       return RBU_PK_EXTERNAL
**     }else{
**       return RBU_PK_WITHOUT_ROWID
**     }
**   }else if( "PRAGMA table_info()" lists one or more "pk" columns ){
**     return RBU_PK_IPK
**   }else{
**     return RBU_PK_NONE
**   }
*/
static void rbuTableType(
  sqlite3rbu *p,
  const char *zTab,
  int *peType,
  int *piTnum,
  int *piPk
){
  /*
  ** 0) SELECT count(*) FROM sqlite_schema where name=%Q AND IsVirtual(%Q)
  ** 1) PRAGMA index_list = ?
  ** 2) SELECT count(*) FROM sqlite_schema where name=%Q 
  ** 3) PRAGMA table_info = ?
  */
  sqlite3_stmt *aStmt[4] = {0, 0, 0, 0};

  *peType = RBU_PK_NOTABLE;
  *piPk = 0;

  assert( p->rc==SQLITE_OK );
  p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[0], &p->zErrmsg, 
    sqlite3_mprintf(
          "SELECT (sql LIKE 'create virtual%%'), rootpage"
          "  FROM sqlite_schema"
          " WHERE name=%Q", zTab
  ));
  if( p->rc!=SQLITE_OK || sqlite3_step(aStmt[0])!=SQLITE_ROW ){
    /* Either an error, or no such table. */
    goto rbuTableType_end;
  }
  if( sqlite3_column_int(aStmt[0], 0) ){

  if( p->rc ) goto rbuTableType_end;
  while( sqlite3_step(aStmt[1])==SQLITE_ROW ){
    const u8 *zOrig = sqlite3_column_text(aStmt[1], 3);
    const u8 *zIdx = sqlite3_column_text(aStmt[1], 1);
    if( zOrig && zIdx && zOrig[0]=='p' ){
      p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[2], &p->zErrmsg, 
          sqlite3_mprintf(
            "SELECT rootpage FROM sqlite_schema WHERE name = %Q", zIdx
      ));
      if( p->rc==SQLITE_OK ){
        if( sqlite3_step(aStmt[2])==SQLITE_ROW ){
          *piPk = sqlite3_column_int(aStmt[2], 0);
          *peType = RBU_PK_EXTERNAL;
        }else{
          *peType = RBU_PK_WITHOUT_ROWID;

    char *zCols = 0;              /* Used to build up list of table cols */
    char *zPk = 0;                /* Used to build up table PK declaration */

    /* Figure out the name of the primary key index for the current table.
    ** This is needed for the argument to "PRAGMA index_xinfo". Set
    ** zIdx to point to a nul-terminated string containing this name. */
    p->rc = prepareAndCollectError(p->dbMain, &pQuery, &p->zErrmsg, 
        "SELECT name FROM sqlite_schema WHERE rootpage = ?"
    );
    if( p->rc==SQLITE_OK ){
      sqlite3_bind_int(pQuery, 1, tnum);
      if( SQLITE_ROW==sqlite3_step(pQuery) ){
        zIdx = (const char*)sqlite3_column_text(pQuery, 0);
      }
    }

  int rc = p->rc;
  char *zRet = 0;

  assert( pIter->zIdxSql==0 && pIter->nIdxCol==0 && pIter->aIdxCol==0 );

  if( rc==SQLITE_OK ){
    rc = prepareAndCollectError(p->dbMain, &pStmt, &p->zErrmsg,
        "SELECT trim(sql) FROM sqlite_schema WHERE type='index' AND name=?"
    );
  }
  if( rc==SQLITE_OK ){
    int rc2;
    rc = sqlite3_bind_text(pStmt, 1, pIter->zIdx, -1, SQLITE_STATIC);
    if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      char *zSql = (char*)sqlite3_column_text(pStmt, 0);

#if 0
  if( rbuIsVacuum(p) ){
    if( p->rc==SQLITE_OK ){
      int rc2;
      int bOk = 0;
      sqlite3_stmt *pCnt = 0;
      p->rc = prepareAndCollectError(p->dbRbu, &pCnt, &p->zErrmsg,
          "SELECT count(*) FROM stat.sqlite_schema"
      );
      if( p->rc==SQLITE_OK 
       && sqlite3_step(pCnt)==SQLITE_ROW
       && 1==sqlite3_column_int(pCnt, 0)
      ){
        bOk = 1;
      }

        "rbu_target_name", -1, SQLITE_UTF8, (void*)p, rbuTargetNameFunc, 0, 0
    );
  }

  if( p->rc==SQLITE_OK ){
    p->rc = sqlite3_file_control(p->dbMain, "main", SQLITE_FCNTL_RBU, (void*)p);
  }
  rbuMPrintfExec(p, p->dbMain, "SELECT * FROM sqlite_schema");

  /* Mark the database file just opened as an RBU target database. If 
  ** this call returns SQLITE_NOTFOUND, then the RBU vfs is not in use.
  ** This is an error.  */
  if( p->rc==SQLITE_OK ){
    p->rc = sqlite3_file_control(p->dbMain, "main", SQLITE_FCNTL_RBU, (void*)p);
  }

  /* If pState is NULL, then the wal file may not have been opened and
  ** recovered. Running a read-statement here to ensure that doing so
  ** does not interfere with the "capture" process below.  */
  if( pState==0 ){
    p->eStage = 0;
    if( p->rc==SQLITE_OK ){
      p->rc = sqlite3_exec(p->dbMain, "SELECT * FROM sqlite_schema", 0, 0, 0);
    }
  }

  /* Assuming no error has occurred, run a "restart" checkpoint with the
  ** sqlite3rbu.eStage variable set to CAPTURE. This turns on the following
  ** special behaviour in the rbu VFS:
  **

  sqlite3_stmt *pSql = 0;
  sqlite3_stmt *pInsert = 0;

  assert( rbuIsVacuum(p) );
  p->rc = sqlite3_exec(p->dbMain, "PRAGMA writable_schema=1", 0,0, &p->zErrmsg);
  if( p->rc==SQLITE_OK ){
    p->rc = prepareAndCollectError(p->dbRbu, &pSql, &p->zErrmsg, 
      "SELECT sql FROM sqlite_schema WHERE sql!='' AND rootpage!=0"
      " AND name!='sqlite_sequence' "
      " ORDER BY type DESC"
    );
  }

  while( p->rc==SQLITE_OK && sqlite3_step(pSql)==SQLITE_ROW ){
    const char *zSql = (const char*)sqlite3_column_text(pSql, 0);
    p->rc = sqlite3_exec(p->dbMain, zSql, 0, 0, &p->zErrmsg);
  }
  rbuFinalize(p, pSql);
  if( p->rc!=SQLITE_OK ) return;

  if( p->rc==SQLITE_OK ){
    p->rc = prepareAndCollectError(p->dbRbu, &pSql, &p->zErrmsg, 
        "SELECT * FROM sqlite_schema WHERE rootpage=0 OR rootpage IS NULL" 
    );
  }

  if( p->rc==SQLITE_OK ){
    p->rc = prepareAndCollectError(p->dbMain, &pInsert, &p->zErrmsg, 
        "INSERT INTO sqlite_schema VALUES(?,?,?,?,?)"
    );
  }

  while( p->rc==SQLITE_OK && sqlite3_step(pSql)==SQLITE_ROW ){
    int i;
    for(i=0; i<5; i++){
      sqlite3_bind_value(pInsert, i+1, sqlite3_column_value(pSql, i));

  char *zErrmsg = 0;
  int rc;
  sqlite3 *db = (rbuIsVacuum(p) ? p->dbRbu : p->dbMain);

  assert( nVal==1 );
  
  rc = prepareFreeAndCollectError(db, &pStmt, &zErrmsg, 
      sqlite3_mprintf("SELECT count(*) FROM sqlite_schema "
        "WHERE type='index' AND tbl_name = %Q", sqlite3_value_text(apVal[0]))
  );
  if( rc!=SQLITE_OK ){
    sqlite3_result_error(pCtx, zErrmsg, -1);
  }else{
    int nIndex = 0;
    if( SQLITE_ROW==sqlite3_step(pStmt) ){

        "rbu_index_cnt", 1, SQLITE_UTF8, (void*)p, rbuIndexCntFunc, 0, 0
    );
  
    /* Check for the rbu_count table. If it does not exist, or if an error
    ** occurs, nPhaseOneStep will be left set to -1. */
    if( p->rc==SQLITE_OK ){
      p->rc = prepareAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg,
          "SELECT 1 FROM sqlite_schema WHERE tbl_name = 'rbu_count'"
      );
    }
    if( p->rc==SQLITE_OK ){
      if( SQLITE_ROW==sqlite3_step(pStmt) ){
        bExists = 1;
      }
      p->rc = sqlite3_finalize(pStmt);

    pCsr->isAgg = sqlite3_value_double(argv[iArg++])!=0.0;
  }else{
    pCsr->isAgg = 0;
  }
  pSql = sqlite3_str_new(pTab->db);
  sqlite3_str_appendf(pSql,
      "SELECT * FROM ("
        "SELECT 'sqlite_schema' AS name,1 AS rootpage,'table' AS type"
        " UNION ALL "
        "SELECT name,rootpage,type"
        " FROM \"%w\".sqlite_schema WHERE rootpage!=0)",
      pTab->db->aDb[pCsr->iDb].zDbSName);
  if( zName ){
    sqlite3_str_appendf(pSql, "WHERE name=%Q", zName);
  }
  if( idxNum & 0x08 ){
    sqlite3_str_appendf(pSql, " ORDER BY name");
  }

  sqlite3_stmt *pInsert;          /* INSERT statement */
  sqlite3_stmt *pSelect;          /* SELECT statement */
  int nCol;                       /* Size of azCol[] and abPK[] arrays */
  const char **azCol;             /* Array of column names */
  u8 *abPK;                       /* Boolean array - true if column is in PK */
  int bStat1;                     /* True if table is sqlite_stat1 */
  int bDeferConstraints;          /* True to defer constraints */
  int bInvertConstraints;         /* Invert when iterating constraints buffer */
  SessionBuffer constraints;      /* Deferred constraints are stored here */
  SessionBuffer rebase;           /* Rebase information (if any) here */
  u8 bRebaseStarted;              /* If table header is already in rebase */
  u8 bRebase;                     /* True to collect rebase information */
};

/*

  int rc = SQLITE_OK;

  while( pApply->constraints.nBuf ){
    sqlite3_changeset_iter *pIter2 = 0;
    SessionBuffer cons = pApply->constraints;
    memset(&pApply->constraints, 0, sizeof(SessionBuffer));

    rc = sessionChangesetStart(
        &pIter2, 0, 0, cons.nBuf, cons.aBuf, pApply->bInvertConstraints
    );
    if( rc==SQLITE_OK ){
      size_t nByte = 2*pApply->nCol*sizeof(sqlite3_value*);
      int rc2;
      pIter2->bPatchset = bPatchset;
      pIter2->zTab = (char*)zTab;
      pIter2->nCol = pApply->nCol;
      pIter2->abPK = pApply->abPK;

  int bPatchset;

  assert( xConflict!=0 );

  pIter->in.bNoDiscard = 1;
  memset(&sApply, 0, sizeof(sApply));
  sApply.bRebase = (ppRebase && pnRebase);
  sApply.bInvertConstraints = !!(flags & SQLITE_CHANGESETAPPLY_INVERT);
  sqlite3_mutex_enter(sqlite3_db_mutex(db));
  if( (flags & SQLITE_CHANGESETAPPLY_NOSAVEPOINT)==0 ){
    rc = sqlite3_exec(db, "SAVEPOINT changeset_apply", 0, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_exec(db, "PRAGMA defer_foreign_keys = 1", 0, 0, 0);
  }

static void fts5SourceIdFunc(
  sqlite3_context *pCtx,          /* Function call context */
  int nArg,                       /* Number of args */
  sqlite3_value **apUnused        /* Function arguments */
){
  assert( nArg==0 );
  UNUSED_PARAM2(nArg, apUnused);
  sqlite3_result_text(pCtx, "fts5: 2020-06-19 15:24:12 7a876209a678a34c198b54ceef9e3c041f128a14dc73357f6a57cadadaa6cf7b", -1, SQLITE_TRANSIENT);
}

/*
** Return true if zName is the extension on one of the shadow tables used
** by this module.
*/
static int fts5ShadowName(const char *zName){

#endif
  return rc;
}
#endif /* SQLITE_CORE */
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_STMTVTAB) */

/************** End of stmt.c ************************************************/
#if __LINE__!=229870
#undef SQLITE_SOURCE_ID
#define SQLITE_SOURCE_ID      "2020-06-19 15:24:12 7a876209a678a34c198b54ceef9e3c041f128a14dc73357f6a57cadadaa6alt2"
#endif
/* Return the source-id for this library */
SQLITE_API const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
/************************** End of sqlite3.c ******************************/