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Overview
Comment:Avoid creating a TEMP database unless it is absolutely necessary. (CVS 1890)
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1:5914a11caa4c6e778cd7ca010427897c8f971552
User & Date: drh 2004-08-18 02:10:15
Context
2004-08-18
15:58
Be more agressive about not creating or opening the TEMP database if there are no TEMP tables. (CVS 1891) check-in: 6b2b6b2d user: drh tags: trunk
02:10
Avoid creating a TEMP database unless it is absolutely necessary. (CVS 1890) check-in: 5914a11c user: drh tags: trunk
2004-08-17
10:42
Fix a typo in a comment. (CVS 1889) check-in: 9af1d4d1 user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/build.c.

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**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.246 2004/08/08 23:39:19 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Check to see if the schema for the database needs
................................................................................
    if( sqlite3AuthCheck(pParse, code, zName, 0, zDb) ){
      sqliteFree(zName);
      return;
    }
  }
#endif

  /* Before trying to create a temporary table, make sure the Btree for
  ** holding temporary tables is open.
  */
  if( isTemp && db->aDb[1].pBt==0 && !pParse->explain ){
    int rc = sqlite3BtreeFactory(db, 0, 0, MAX_PAGES, &db->aDb[1].pBt);
    if( rc!=SQLITE_OK ){
      sqlite3ErrorMsg(pParse, "unable to open a temporary database "
        "file for storing temporary tables");
      pParse->nErr++;
      pParse->rc = rc;
      sqliteFree(zName);
      return;
    }
    if( db->flags & !db->autoCommit ){
      rc = sqlite3BtreeBeginTrans(db->aDb[1].pBt, 1);
      if( rc!=SQLITE_OK ){
        sqlite3ErrorMsg(pParse, "unable to get a write lock on "
          "the temporary database file");
        sqliteFree(zName);
        pParse->rc = rc;
        return;
      }
    }
  }

  /* Make sure the new table name does not collide with an existing
  ** index or table name in the same database.  Issue an error message if
  ** it does.
  */
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) return;
  pTable = sqlite3FindTable(db, zName, db->aDb[iDb].zName);
  if( pTable ){
................................................................................
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "ROLLBACK", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_AutoCommit, 1, 1);
  }
}




























/*
** Generate VDBE code that will verify the schema cookie and start
** a read-transaction for all named database files.
**
** It is important that all schema cookies be verified and all
** read transactions be started before anything else happens in
................................................................................
    assert( iDb<db->nDb );
    assert( db->aDb[iDb].pBt!=0 || iDb==1 );
    assert( iDb<32 );
    mask = 1<<iDb;
    if( (pParse->cookieMask & mask)==0 ){
      pParse->cookieMask |= mask;
      pParse->cookieValue[iDb] = db->aDb[iDb].schema_cookie;



    }
  }
}

/*
** Generate VDBE code that prepares for doing an operation that
** might change the database.







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**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.247 2004/08/18 02:10:15 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Check to see if the schema for the database needs
................................................................................
    if( sqlite3AuthCheck(pParse, code, zName, 0, zDb) ){
      sqliteFree(zName);
      return;
    }
  }
#endif


























  /* Make sure the new table name does not collide with an existing
  ** index or table name in the same database.  Issue an error message if
  ** it does.
  */
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) return;
  pTable = sqlite3FindTable(db, zName, db->aDb[iDb].zName);
  if( pTable ){
................................................................................
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "ROLLBACK", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_AutoCommit, 1, 1);
  }
}

/*
** Make sure the TEMP database is open and available for use.  Return
** the number of errors.  Leave any error messages in the pParse structure.
*/
static int sqlite3OpenTempDatabase(Parse *pParse){
  sqlite3 *db = pParse->db;
  if( db->aDb[1].pBt==0 && !pParse->explain ){
    int rc = sqlite3BtreeFactory(db, 0, 0, MAX_PAGES, &db->aDb[1].pBt);
    if( rc!=SQLITE_OK ){
      sqlite3ErrorMsg(pParse, "unable to open a temporary database "
        "file for storing temporary tables");
      pParse->rc = rc;
      return 1;
    }
    if( db->flags & !db->autoCommit ){
      rc = sqlite3BtreeBeginTrans(db->aDb[1].pBt, 1);
      if( rc!=SQLITE_OK ){
        sqlite3ErrorMsg(pParse, "unable to get a write lock on "
          "the temporary database file");
        pParse->rc = rc;
        return 1;
      }
    }
  }
  return 0;
}

/*
** Generate VDBE code that will verify the schema cookie and start
** a read-transaction for all named database files.
**
** It is important that all schema cookies be verified and all
** read transactions be started before anything else happens in
................................................................................
    assert( iDb<db->nDb );
    assert( db->aDb[iDb].pBt!=0 || iDb==1 );
    assert( iDb<32 );
    mask = 1<<iDb;
    if( (pParse->cookieMask & mask)==0 ){
      pParse->cookieMask |= mask;
      pParse->cookieValue[iDb] = db->aDb[iDb].schema_cookie;
      if( iDb==1 ){
        sqlite3OpenTempDatabase(pParse);
      }
    }
  }
}

/*
** Generate VDBE code that prepares for doing an operation that
** might change the database.

Changes to src/main.c.

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**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.251 2004/08/14 19:20:10 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** The following constant value is used by the SQLITE_BIGENDIAN and
................................................................................
  if( pTab ){
    pTab->readOnly = 1;
  }
  sqlite3SafetyOn(db);

  /* Create a cursor to hold the database open
  */
  if( db->aDb[iDb].pBt==0 ) return SQLITE_OK;



  rc = sqlite3BtreeCursor(db->aDb[iDb].pBt, MASTER_ROOT, 0, 0, 0, &curMain);
  if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
    sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
    return rc;
  }

  /* Get the database meta information.







|







 







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**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.252 2004/08/18 02:10:15 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** The following constant value is used by the SQLITE_BIGENDIAN and
................................................................................
  if( pTab ){
    pTab->readOnly = 1;
  }
  sqlite3SafetyOn(db);

  /* Create a cursor to hold the database open
  */
  if( db->aDb[iDb].pBt==0 ){
    if( iDb==1 ) DbSetProperty(db, 1, DB_SchemaLoaded);
    return SQLITE_OK;
  }
  rc = sqlite3BtreeCursor(db->aDb[iDb].pBt, MASTER_ROOT, 0, 0, 0, &curMain);
  if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
    sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
    return rc;
  }

  /* Get the database meta information.

Changes to src/pager.c.

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** 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 1.154 2004/08/07 23:54:48 drh Exp $
*/
#include "os.h"         /* Must be first to enable large file support */
#include "sqliteInt.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

................................................................................
}

/*
** Truncate the file to the number of pages specified.
*/
int sqlite3pager_truncate(Pager *pPager, Pgno nPage){
  int rc;
  if( pPager->dbSize<0 ){
    sqlite3pager_pagecount(pPager);
  }
  if( pPager->errMask!=0 ){
    rc = pager_errcode(pPager);
    return rc;
  }
  if( nPage>=(unsigned)pPager->dbSize ){
    return SQLITE_OK;
  }
................................................................................
    if( pPg->pNextHash ){
      assert( pPg->pNextHash->pPrevHash==0 );
      pPg->pNextHash->pPrevHash = pPg;
    }
    if( pPager->nExtra>0 ){
      memset(PGHDR_TO_EXTRA(pPg, pPager), 0, pPager->nExtra);
    }
    if( pPager->dbSize<0 ) sqlite3pager_pagecount(pPager);
    if( pPager->errMask!=0 ){
      sqlite3pager_unref(PGHDR_TO_DATA(pPg));
      rc = pager_errcode(pPager);
      return rc;
    }
    if( pPager->dbSize<(int)pgno ){
      memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
................................................................................
** open.  A new statement journal is created that can be used to rollback
** changes of a single SQL command within a larger transaction.
*/
int sqlite3pager_stmt_begin(Pager *pPager){
  int rc;
  char zTemp[SQLITE_TEMPNAME_SIZE];
  assert( !pPager->stmtInUse );

  TRACE2("STMT-BEGIN %d\n", pPager->fd.h);
  if( pPager->memDb ){
    pPager->stmtInUse = 1;
    pPager->stmtSize = pPager->dbSize;
    return SQLITE_OK;
  }
  if( !pPager->journalOpen ){







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** 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 1.155 2004/08/18 02:10:15 drh Exp $
*/
#include "os.h"         /* Must be first to enable large file support */
#include "sqliteInt.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

................................................................................
}

/*
** Truncate the file to the number of pages specified.
*/
int sqlite3pager_truncate(Pager *pPager, Pgno nPage){
  int rc;

  sqlite3pager_pagecount(pPager);

  if( pPager->errMask!=0 ){
    rc = pager_errcode(pPager);
    return rc;
  }
  if( nPage>=(unsigned)pPager->dbSize ){
    return SQLITE_OK;
  }
................................................................................
    if( pPg->pNextHash ){
      assert( pPg->pNextHash->pPrevHash==0 );
      pPg->pNextHash->pPrevHash = pPg;
    }
    if( pPager->nExtra>0 ){
      memset(PGHDR_TO_EXTRA(pPg, pPager), 0, pPager->nExtra);
    }
    sqlite3pager_pagecount(pPager);
    if( pPager->errMask!=0 ){
      sqlite3pager_unref(PGHDR_TO_DATA(pPg));
      rc = pager_errcode(pPager);
      return rc;
    }
    if( pPager->dbSize<(int)pgno ){
      memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
................................................................................
** open.  A new statement journal is created that can be used to rollback
** changes of a single SQL command within a larger transaction.
*/
int sqlite3pager_stmt_begin(Pager *pPager){
  int rc;
  char zTemp[SQLITE_TEMPNAME_SIZE];
  assert( !pPager->stmtInUse );
  assert( pPager->dbSize>=0 );
  TRACE2("STMT-BEGIN %d\n", pPager->fd.h);
  if( pPager->memDb ){
    pPager->stmtInUse = 1;
    pPager->stmtSize = pPager->dbSize;
    return SQLITE_OK;
  }
  if( !pPager->journalOpen ){

Changes to src/util.c.

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**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.112 2004/08/08 20:22:18 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

#if SQLITE_DEBUG>2 && defined(__GLIBC__)
#include <execinfo.h>
................................................................................
/*
** Convert the UTF-8 character to which z points into a 31-bit
** UCS character.  This only works right if z points to a well-formed
** UTF-8 string.
*/
int sqlite3ReadUtf8(const unsigned char *z){
  int c;
  static const int initVal[] = {
      0,   1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
     15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,  29,
     30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,
     45,  46,  47,  48,  49,  50,  51,  52,  53,  54,  55,  56,  57,  58,  59,
     60,  61,  62,  63,  64,  65,  66,  67,  68,  69,  70,  71,  72,  73,  74,
     75,  76,  77,  78,  79,  80,  81,  82,  83,  84,  85,  86,  87,  88,  89,
     90,  91,  92,  93,  94,  95,  96,  97,  98,  99, 100, 101, 102, 103, 104,







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**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.113 2004/08/18 02:10:15 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

#if SQLITE_DEBUG>2 && defined(__GLIBC__)
#include <execinfo.h>
................................................................................
/*
** Convert the UTF-8 character to which z points into a 31-bit
** UCS character.  This only works right if z points to a well-formed
** UTF-8 string.
*/
int sqlite3ReadUtf8(const unsigned char *z){
  int c;
  static const char initVal[] = {
      0,   1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
     15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,  29,
     30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,
     45,  46,  47,  48,  49,  50,  51,  52,  53,  54,  55,  56,  57,  58,  59,
     60,  61,  62,  63,  64,  65,  66,  67,  68,  69,  70,  71,  72,  73,  74,
     75,  76,  77,  78,  79,  80,  81,  82,  83,  84,  85,  86,  87,  88,  89,
     90,  91,  92,  93,  94,  95,  96,  97,  98,  99, 100, 101, 102, 103, 104,

Changes to test/attach2.test.

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#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the ATTACH and DETACH commands
# and related functionality.
#
# $Id: attach2.test,v 1.22 2004/07/19 17:25:25 drh Exp $
#

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


# Ticket #354
................................................................................
do_test attach2-4.1 {
  sqlite3 db test.db
  sqlite3 db2 test.db
  execsql {ATTACH 'test2.db' as file2}
  execsql {ATTACH 'test2.db' as file2} db2
} {}

lock_status 4.1.1 db {main unlocked temp unlocked file2 unlocked}
lock_status 4.1.2 db2 {main unlocked temp unlocked file2 unlocked}

do_test attach2-4.2 {
  # Handle 'db' read-locks test.db
  execsql {BEGIN}
  execsql {SELECT * FROM t1}
  # Lock status:
  #    db  - shared(main)
  #    db2 -
} {}

lock_status 4.2.1 db {main shared temp unlocked file2 unlocked}
lock_status 4.2.2 db2 {main unlocked temp unlocked file2 unlocked}

do_test attach2-4.3 {
  # The read lock held by db does not prevent db2 from reading test.db
  execsql {SELECT * FROM t1} db2
} {}

lock_status 4.3.1 db {main shared temp unlocked file2 unlocked}
lock_status 4.3.2 db2 {main unlocked temp unlocked file2 unlocked}

do_test attach2-4.4 {
  # db is holding a read lock on test.db, so we should not be able
  # to commit a write to test.db from db2
  catchsql {
    INSERT INTO t1 VALUES(1, 2)
  } db2 
} {1 {database is locked}}

lock_status 4.4.1 db {main shared temp unlocked file2 unlocked}
lock_status 4.4.2 db2 {main unlocked temp unlocked file2 unlocked}

do_test attach2-4.5 {
  # Handle 'db2' reserves file2.
  execsql {BEGIN} db2
  execsql {INSERT INTO file2.t1 VALUES(1, 2)} db2
  # Lock status:
  #    db  - shared(main)
  #    db2 - reserved(file2)
} {}

lock_status 4.5.1 db {main shared temp unlocked file2 unlocked}
lock_status 4.5.2 db2 {main unlocked temp reserved file2 reserved}

do_test attach2-4.6.1 {
  # Reads are allowed against a reserved database.
  catchsql {
    SELECT * FROM file2.t1;
  }
  # Lock status:
  #    db  - shared(main), shared(file2)
  #    db2 - reserved(file2)
} {0 {}}

lock_status 4.6.1.1 db {main shared temp unlocked file2 shared}
lock_status 4.6.1.2 db2 {main unlocked temp reserved file2 reserved}

do_test attach2-4.6.2 {
  # Writes against a reserved database are not allowed.
  catchsql {
    UPDATE file2.t1 SET a=0;
  }







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#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the ATTACH and DETACH commands
# and related functionality.
#
# $Id: attach2.test,v 1.23 2004/08/18 02:10:15 drh Exp $
#

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


# Ticket #354
................................................................................
do_test attach2-4.1 {
  sqlite3 db test.db
  sqlite3 db2 test.db
  execsql {ATTACH 'test2.db' as file2}
  execsql {ATTACH 'test2.db' as file2} db2
} {}

lock_status 4.1.1 db {main unlocked temp closed file2 unlocked}
lock_status 4.1.2 db2 {main unlocked temp closed file2 unlocked}

do_test attach2-4.2 {
  # Handle 'db' read-locks test.db
  execsql {BEGIN}
  execsql {SELECT * FROM t1}
  # Lock status:
  #    db  - shared(main)
  #    db2 -
} {}

lock_status 4.2.1 db {main shared temp closed file2 unlocked}
lock_status 4.2.2 db2 {main unlocked temp closed file2 unlocked}

do_test attach2-4.3 {
  # The read lock held by db does not prevent db2 from reading test.db
  execsql {SELECT * FROM t1} db2
} {}

lock_status 4.3.1 db {main shared temp closed file2 unlocked}
lock_status 4.3.2 db2 {main unlocked temp closed file2 unlocked}

do_test attach2-4.4 {
  # db is holding a read lock on test.db, so we should not be able
  # to commit a write to test.db from db2
  catchsql {
    INSERT INTO t1 VALUES(1, 2)
  } db2 
} {1 {database is locked}}

lock_status 4.4.1 db {main shared temp closed file2 unlocked}
lock_status 4.4.2 db2 {main unlocked temp unlocked file2 unlocked}

do_test attach2-4.5 {
  # Handle 'db2' reserves file2.
  execsql {BEGIN} db2
  execsql {INSERT INTO file2.t1 VALUES(1, 2)} db2
  # Lock status:
  #    db  - shared(main)
  #    db2 - reserved(file2)
} {}

lock_status 4.5.1 db {main shared temp closed file2 unlocked}
lock_status 4.5.2 db2 {main unlocked temp reserved file2 reserved}

do_test attach2-4.6.1 {
  # Reads are allowed against a reserved database.
  catchsql {
    SELECT * FROM file2.t1;
  }
  # Lock status:
  #    db  - shared(main), shared(file2)
  #    db2 - reserved(file2)
} {0 {}}

lock_status 4.6.1.1 db {main shared temp closed file2 shared}
lock_status 4.6.1.2 db2 {main unlocked temp reserved file2 reserved}

do_test attach2-4.6.2 {
  # Writes against a reserved database are not allowed.
  catchsql {
    UPDATE file2.t1 SET a=0;
  }