/ Check-in [acca97ef]
Login
SQLite training in Houston TX on 2019-11-05 (details)
Part of the 2019 Tcl Conference

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Fix a problem with sorting large amounts of partially ordered data.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: acca97efda86a0c020854d2dd9da16f5879986b1
User & Date: dan 2015-04-11 20:20:29
Context
2015-04-11
20:44
Optimizations for VACUUM, CREATE INDEX and some cases of ORDER BY. check-in: 79326d6e user: dan tags: trunk
20:20
Fix a problem with sorting large amounts of partially ordered data. check-in: acca97ef user: dan tags: trunk
13:49
Add the --changeset option to the sqldiff utility program, for generating a sessions changeset file instead of an SQL diff. check-in: f9a3a839 user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/vdbesort.c.

883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913

914
915
916
917
918
919
920
....
1086
1087
1088
1089
1090
1091
1092

1093
1094
1095
1096
1097
1098
1099

/*
** Free all resources owned by the object indicated by argument pTask. All 
** fields of *pTask are zeroed before returning.
*/
static void vdbeSortSubtaskCleanup(sqlite3 *db, SortSubtask *pTask){
  sqlite3DbFree(db, pTask->pUnpacked);
  pTask->pUnpacked = 0;
#if SQLITE_MAX_WORKER_THREADS>0
  /* pTask->list.aMemory can only be non-zero if it was handed memory
  ** from the main thread.  That only occurs SQLITE_MAX_WORKER_THREADS>0 */
  if( pTask->list.aMemory ){
    sqlite3_free(pTask->list.aMemory);
    pTask->list.aMemory = 0;
  }else
#endif
  {
    assert( pTask->list.aMemory==0 );
    vdbeSorterRecordFree(0, pTask->list.pList);
  }
  pTask->list.pList = 0;
  if( pTask->file.pFd ){
    sqlite3OsCloseFree(pTask->file.pFd);
    pTask->file.pFd = 0;
    pTask->file.iEof = 0;
  }
  if( pTask->file2.pFd ){
    sqlite3OsCloseFree(pTask->file2.pFd);
    pTask->file2.pFd = 0;
    pTask->file2.iEof = 0;
  }

}

#ifdef SQLITE_DEBUG_SORTER_THREADS
static void vdbeSorterWorkDebug(SortSubtask *pTask, const char *zEvent){
  i64 t;
  int iTask = (pTask - pTask->pSorter->aTask);
  sqlite3OsCurrentTimeInt64(pTask->pSorter->db->pVfs, &t);
................................................................................
  }
#endif
  vdbeMergeEngineFree(pSorter->pMerger);
  pSorter->pMerger = 0;
  for(i=0; i<pSorter->nTask; i++){
    SortSubtask *pTask = &pSorter->aTask[i];
    vdbeSortSubtaskCleanup(db, pTask);

  }
  if( pSorter->list.aMemory==0 ){
    vdbeSorterRecordFree(0, pSorter->list.pList);
  }
  pSorter->list.pList = 0;
  pSorter->list.szPMA = 0;
  pSorter->bUsePMA = 0;







<





<






<


<
<



<
<

>







 







>







883
884
885
886
887
888
889

890
891
892
893
894

895
896
897
898
899
900

901
902


903
904
905


906
907
908
909
910
911
912
913
914
....
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094

/*
** Free all resources owned by the object indicated by argument pTask. All 
** fields of *pTask are zeroed before returning.
*/
static void vdbeSortSubtaskCleanup(sqlite3 *db, SortSubtask *pTask){
  sqlite3DbFree(db, pTask->pUnpacked);

#if SQLITE_MAX_WORKER_THREADS>0
  /* pTask->list.aMemory can only be non-zero if it was handed memory
  ** from the main thread.  That only occurs SQLITE_MAX_WORKER_THREADS>0 */
  if( pTask->list.aMemory ){
    sqlite3_free(pTask->list.aMemory);

  }else
#endif
  {
    assert( pTask->list.aMemory==0 );
    vdbeSorterRecordFree(0, pTask->list.pList);
  }

  if( pTask->file.pFd ){
    sqlite3OsCloseFree(pTask->file.pFd);


  }
  if( pTask->file2.pFd ){
    sqlite3OsCloseFree(pTask->file2.pFd);


  }
  memset(pTask, 0, sizeof(SortSubtask));
}

#ifdef SQLITE_DEBUG_SORTER_THREADS
static void vdbeSorterWorkDebug(SortSubtask *pTask, const char *zEvent){
  i64 t;
  int iTask = (pTask - pTask->pSorter->aTask);
  sqlite3OsCurrentTimeInt64(pTask->pSorter->db->pVfs, &t);
................................................................................
  }
#endif
  vdbeMergeEngineFree(pSorter->pMerger);
  pSorter->pMerger = 0;
  for(i=0; i<pSorter->nTask; i++){
    SortSubtask *pTask = &pSorter->aTask[i];
    vdbeSortSubtaskCleanup(db, pTask);
    pTask->pSorter = pSorter;
  }
  if( pSorter->list.aMemory==0 ){
    vdbeSorterRecordFree(0, pSorter->list.pList);
  }
  pSorter->list.pList = 0;
  pSorter->list.szPMA = 0;
  pSorter->bUsePMA = 0;

Changes to test/orderby1.test.

491
492
493
494
495
496
497



498


























499
  CREATE TABLE t7(a,b);
  CREATE INDEX t7a ON t7(a);
  CREATE INDEX t7ab ON t7(a,b);
  EXPLAIN QUERY PLAN
  SELECT * FROM t7 WHERE a=?1 ORDER BY rowid;
} {~/ORDER BY/}































finish_test







>
>
>
|
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>

491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
  CREATE TABLE t7(a,b);
  CREATE INDEX t7a ON t7(a);
  CREATE INDEX t7ab ON t7(a,b);
  EXPLAIN QUERY PLAN
  SELECT * FROM t7 WHERE a=?1 ORDER BY rowid;
} {~/ORDER BY/}

#-------------------------------------------------------------------------
# Test a partial sort large enough to cause the sorter to spill data
# to disk.
#
reset_db
do_execsql_test 8.0 {
  PRAGMA cache_size = 5;
  CREATE TABLE t1(a, b);
  CREATE INDEX i1 ON t1(a);
}

do_eqp_test 8.1 {
  SELECT * FROM t1 ORDER BY a, b;
} {
  0 0 0 {SCAN TABLE t1 USING INDEX i1} 
  0 0 0 {USE TEMP B-TREE FOR RIGHT PART OF ORDER BY}
}

do_execsql_test 8.2 {
  WITH cnt(i) AS (
    SELECT 1 UNION ALL SELECT i+1 FROM cnt WHERE i<10000
  )
  INSERT INTO t1 SELECT i%2, randomblob(500) FROM cnt;
}

do_test 8.3 {
  db eval { SELECT * FROM t1 ORDER BY a, b } { incr res $a }
  set res
} 5000

finish_test