SQLite: Check-in [76f23a43]

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Overview

Comment:	A backup must clear the internal schema of the destination database so that the schema will be reloaded for the next sqlite3_prepare() (CVS 6247)
Downloads:	Tarball \| ZIP archive \| SQL archive
Timelines:	family \| ancestors \| descendants \| both \| trunk
Files:	files \| file ages \| folders
SHA1:	76f23a4394574e31f237e55c641bc70534f44d97
User & Date:	drh 2009-02-03 22:17:42

Context

2009-02-03
22:51		Correction to check-ins (6246) and (6247): The backup object might not hold a valid destination connection pointer. Also, do not reset the page cache when establishing a read-lock while there is a persistent or truncated journal, only if there is a journal that really needs to rollback. Otherwise backups always reset whenever the source database file is read. (CVS 6248) check-in: 7f827ba9 user: drh tags: trunk
22:17		A backup must clear the internal schema of the destination database so that the schema will be reloaded for the next sqlite3_prepare() (CVS 6247) check-in: 76f23a43 user: drh tags: trunk
21:13		Must hold mutex on the destination during backups. Add documentation to warn programmers that attempting to use the destination connection during a backup can lead to deadlock. (CVS 6246) check-in: 5f6c06b9 user: drh tags: trunk

Changes

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Changes to src/backup.c.

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_backup_XXX() 
** API functions and the related features.
**
** $Id: backup.c,v 1.2 2009/02/03 21:13:08 drh Exp $
*/
#include "sqliteInt.h"
#include "btreeInt.h"

/* Macro to find the minimum of two numeric values.
*/
#ifndef MIN
................................................................................
  
      /* Update the schema version field in the destination database. This
      ** is to make sure that the schema-version really does change in
      ** the case where the source and destination databases have the
      ** same schema version.
      */
      sqlite3BtreeUpdateMeta(p->pDest, 1, p->iDestSchema+1);


      /* Set nDestTruncate to the final number of pages in the destination
      ** database. The complication here is that the destination page
      ** size may be different to the source page size. 
      **
      ** If the source page size is smaller than the destination page size, 
      ** round up. In this case the call to sqlite3OsTruncate() below will

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_backup_XXX() 
** API functions and the related features.
**
** $Id: backup.c,v 1.3 2009/02/03 22:17:42 drh Exp $
*/
#include "sqliteInt.h"
#include "btreeInt.h"

/* Macro to find the minimum of two numeric values.
*/
#ifndef MIN
................................................................................
  
      /* Update the schema version field in the destination database. This
      ** is to make sure that the schema-version really does change in
      ** the case where the source and destination databases have the
      ** same schema version.
      */
      sqlite3BtreeUpdateMeta(p->pDest, 1, p->iDestSchema+1);
      sqlite3ResetInternalSchema(p->pDestDb, 0);

      /* Set nDestTruncate to the final number of pages in the destination
      ** database. The complication here is that the destination page
      ** size may be different to the source page size. 
      **
      ** If the source page size is smaller than the destination page size, 
      ** round up. In this case the call to sqlite3OsTruncate() below will

Changes to src/build.c.

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.515 2009/02/03 16:51:25 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
*/
................................................................................
/*
** Erase all schema information from the in-memory hash tables of
** a single database.  This routine is called to reclaim memory
** before the database closes.  It is also called during a rollback
** if there were schema changes during the transaction or if a
** schema-cookie mismatch occurs.
**
** If iDb<=0 then reset the internal schema tables for all database
** files.  If iDb>=2 then reset the internal schema for only the
** single file indicated.
*/
void sqlite3ResetInternalSchema(sqlite3 *db, int iDb){
  int i, j;
  assert( iDb>=0 && iDb<db->nDb );

  if( iDb==0 ){

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.516 2009/02/03 22:17:42 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
*/
................................................................................
/*
** Erase all schema information from the in-memory hash tables of
** a single database.  This routine is called to reclaim memory
** before the database closes.  It is also called during a rollback
** if there were schema changes during the transaction or if a
** schema-cookie mismatch occurs.
**
** If iDb==0 then reset the internal schema tables for all database
** files.  If iDb>=1 then reset the internal schema for only the
** single file indicated.
*/
void sqlite3ResetInternalSchema(sqlite3 *db, int iDb){
  int i, j;
  assert( iDb>=0 && iDb<db->nDb );

  if( iDb==0 ){