SQLite

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.393 2006/03/24 03:36:26 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.

#endif /* SQLITE_OMIT_VIEW */

/*
** This function is called by the VDBE to adjust the internal schema
** used by SQLite when the btree layer moves a table root page. The
** root-page of a table or index in database iDb has changed from iFrom
** to iTo.
**
** Ticket #1728:  The symbol table might still contain information
** on tables and/or indices that are the process of being deleted.
** If you are unlucky, one of those deleted indices or tables might
** have the same rootpage number as the real table or index that is
** being moved.  So we cannot stop searching after the first match 
** because the first match might be for one of the deleted indices
** or tables and not the table/index that is actually being moved.
** We must continue looping until all tables and indices with
** rootpage==iFrom have been converted to have a rootpage of iTo
** in order to be certain that we got the right one.
*/
#ifndef SQLITE_OMIT_AUTOVACUUM
void sqlite3RootPageMoved(Db *pDb, int iFrom, int iTo){
  HashElem *pElem;
  Hash *pHash;

  pHash = &pDb->pSchema->tblHash;
  for(pElem=sqliteHashFirst(pHash); pElem; pElem=sqliteHashNext(pElem)){
    Table *pTab = sqliteHashData(pElem);
    if( pTab->tnum==iFrom ){
      pTab->tnum = iTo;

    }
  }
  pHash = &pDb->pSchema->idxHash;
  for(pElem=sqliteHashFirst(pHash); pElem; pElem=sqliteHashNext(pElem)){
    Index *pIdx = sqliteHashData(pElem);
    if( pIdx->tnum==iFrom ){
      pIdx->tnum = iTo;

    }
  }

}
#endif

/*
** Write code to erase the table with root-page iTable from database iDb.
** Also write code to modify the sqlite_master table and internal schema
** if a root-page of another table is moved by the btree-layer whilst

# 2001 September 15
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the SELECT statement.
#
# $Id: autovacuum.test,v 1.22 2006/03/24 03:36:26 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If this build of the library does not support auto-vacuum, omit this
# whole file.
ifcapable {!autovacuum || !pragma} {

    PRAGMA auto_vacuum=1;
    CREATE TABLE t1(a);
    CREATE TABLE t2(a);
    DROP TABLE t1;
    PRAGMA integrity_check;
  }
} ok

# Ticket #1728.
#
# In autovacuum mode, when tables or indices are deleted, the rootpage
# values in the symbol table have to be updated.  There was a bug in this
# logic so that if an index/table was moved twice, the second move might
# not occur.  This would leave the internal symbol table in an inconsistent
# state causing subsequent statements to fail.
#
# The problem is difficult to reproduce.  The sequence of statements in
# the following test are carefully designed make it occur and thus to
# verify that this very obscure bug has been resolved.
# 
do_test autovacuum-6.1 {
  db close
  sqlite3 db :memory:
  db eval {
    PRAGMA auto_vacuum=1;
    CREATE TABLE t1(a, b);
    CREATE INDEX i1 ON t1(a);
    CREATE TABLE t2(a);
    CREATE INDEX i2 ON t2(a);
    CREATE TABLE t3(a);
    CREATE INDEX i3 ON t2(a);
    CREATE INDEX x ON t1(b);
    DROP TABLE t3;
    PRAGMA integrity_check;
    DROP TABLE t2;
    PRAGMA integrity_check;
    DROP TABLE t1;
    PRAGMA integrity_check;
  }
} {ok ok ok}

finish_test