2.5.2

2.5.3

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.46 2002/05/30 12:27:03 drh Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
#include "os.h"
#include <assert.h>
#include <string.h>

................................................................................
** sqlitepager_dont_rollback() below, more than double the speed
** of large INSERT operations and quadruple the speed of large DELETEs.
*/
void sqlitepager_dont_write(Pager *pPager, Pgno pgno){
  PgHdr *pPg;
  pPg = pager_lookup(pPager, pgno);
  if( pPg && pPg->dirty ){










    pPg->dirty = 0;

  }
}

/*
** A call to this routine tells the pager that if a rollback occurs,
** it is not necessary to restore the data on the given page.  This
** means that the pager does not have to record the given page in the

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.47 2002/06/25 14:43:58 drh Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
#include "os.h"
#include <assert.h>
#include <string.h>

................................................................................
** sqlitepager_dont_rollback() below, more than double the speed
** of large INSERT operations and quadruple the speed of large DELETEs.
*/
void sqlitepager_dont_write(Pager *pPager, Pgno pgno){
  PgHdr *pPg;
  pPg = pager_lookup(pPager, pgno);
  if( pPg && pPg->dirty ){
    if( pPager->dbSize==(int)pPg->pgno && pPager->origDbSize<pPager->dbSize ){
      /* If this pages is the last page in the file and the file has grown
      ** during the current transaction, then do NOT mark the page as clean.
      ** When the database file grows, we must make sure that the last page
      ** gets written at least once so that the disk file will be the correct
      ** size. If you do not write this page and the size of the file
      ** on the disk ends up being too small, that can lead to database
      ** corruption during the next transaction.
      */
    }else{
      pPg->dirty = 0;
    }
  }
}

/*
** A call to this routine tells the pager that if a rollback occurs,
** it is not necessary to restore the data on the given page.  This
** means that the pager does not have to record the given page in the

}


proc chng {date desc} {
  puts "<DT><B>$date</B></DT>"
  puts "<DD><P><UL>$desc</UL></P></DD>"
}








chng {2002 Jun 24 (2.5.2)} {
<li>Added the new <b>SQLITE_TEMP_MASTER</b> table which records the schema
    for temporary tables in the same way that <b>SQLITE_MASTER</b> does for
    persistent tables.</li>
<li>Added an optimization to UNION ALL</li>
<li>Fixed a bug in the processing of LEFT OUTER JOIN</li>

}


proc chng {date desc} {
  puts "<DT><B>$date</B></DT>"
  puts "<DD><P><UL>$desc</UL></P></DD>"
}

chng {2002 Jun 24 (2.5.3)} {
<li>Bug fix:  Database corruption can occur due to the optimization
    that was introduced in version 2.4.0 (checking [410]).  The problem
    should now be fixed.  The use of versions 2.4.0 through 2.5.2 is
    not recommended.</li>
}

chng {2002 Jun 24 (2.5.2)} {
<li>Added the new <b>SQLITE_TEMP_MASTER</b> table which records the schema
    for temporary tables in the same way that <b>SQLITE_MASTER</b> does for
    persistent tables.</li>
<li>Added an optimization to UNION ALL</li>
<li>Fixed a bug in the processing of LEFT OUTER JOIN</li>