/ Check-in [35a20a5f]
Login

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

Overview
Comment:Experimental opimizations to speed up FK constraint CASCADE and SET NULL action processing. Requires further testing.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | experimental-fk-actions
Files: files | file ages | folders
SHA1:35a20a5f22245c70faa51965951e8cc011defa93
User & Date: dan 2014-12-16 20:13:30
Original Comment: Experimental opimizations to speed up FK constraint CASCADE and SET NULL action processing.
Context
2014-12-17
14:38
Fix some comments in fkey.c. Add tests to fkey8.test. Closed-Leaf check-in: 210cb2a6 user: dan tags: experimental-fk-actions
2014-12-16
20:13
Experimental opimizations to speed up FK constraint CASCADE and SET NULL action processing. Requires further testing. check-in: 35a20a5f user: dan tags: experimental-fk-actions
00:20
Enhanced "stress2" testing in the threadtest3.c test program. check-in: ae43539e user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/fkey.c.

433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
...
504
505
506
507
508
509
510




511
512
513
514
515
516
517
...
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
...
805
806
807
808
809
810
811


















812
813
814
815
816
817
818
...
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
...
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
...
932
933
934
935
936
937
938
939
940
941
942
943






944
945
946
947
948
949
950
951
...
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
...
983
984
985
986
987
988
989
990
991
992
993
994
995
996







997
998
999
1000
1001
1002
1003
    ** incrementing a counter. This is necessary as the VM code is being
    ** generated for will not open a statement transaction.  */
    assert( nIncr==1 );
    sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,
        OE_Abort, 0, P4_STATIC, P5_ConstraintFK);
  }else{
    if( nIncr>0 && pFKey->isDeferred==0 ){
      sqlite3ParseToplevel(pParse)->mayAbort = 1;
    }
    sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
  }

  sqlite3VdbeResolveLabel(v, iOk);
  sqlite3VdbeAddOp1(v, OP_Close, iCur);
}
................................................................................

/*
** This function is called to generate code executed when a row is deleted
** from the parent table of foreign key constraint pFKey and, if pFKey is 
** deferred, when a row is inserted into the same table. When generating
** code for an SQL UPDATE operation, this function may be called twice -
** once to "delete" the old row and once to "insert" the new row.




**
** The code generated by this function scans through the rows in the child
** table that correspond to the parent table row being deleted or inserted.
** For each child row found, one of the following actions is taken:
**
**   Operation | FK type   | Action taken
**   --------------------------------------------------------------------------
................................................................................
  sqlite3ResolveExprNames(&sNameContext, pWhere);

  /* Create VDBE to loop through the entries in pSrc that match the WHERE
  ** clause. If the constraint is not deferred, throw an exception for
  ** each row found. Otherwise, for deferred constraints, increment the
  ** deferred constraint counter by nIncr for each row selected.  */
  pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0, 0, 0);
  if( nIncr>0 && pFKey->isDeferred==0 ){
    sqlite3ParseToplevel(pParse)->mayAbort = 1;
  }
  sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
  if( pWInfo ){
    sqlite3WhereEnd(pWInfo);
  }

  /* Clean up the WHERE clause constructed above. */
  sqlite3ExprDelete(db, pWhere);
................................................................................
          return 1;
        }
      }
    }
  }
  return 0;
}



















/*
** This function is called when inserting, deleting or updating a row of
** table pTab to generate VDBE code to perform foreign key constraint 
** processing for the operation.
**
** For a DELETE operation, parameter regOld is passed the index of the
................................................................................
  for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){
    Table *pTo;                   /* Parent table of foreign key pFKey */
    Index *pIdx = 0;              /* Index on key columns in pTo */
    int *aiFree = 0;
    int *aiCol;
    int iCol;
    int i;
    int isIgnore = 0;

    if( aChange 
     && sqlite3_stricmp(pTab->zName, pFKey->zTo)!=0
     && fkChildIsModified(pTab, pFKey, aChange, bChngRowid)==0 
    ){
      continue;
    }
................................................................................
      /* Request permission to read the parent key columns. If the 
      ** authorization callback returns SQLITE_IGNORE, behave as if any
      ** values read from the parent table are NULL. */
      if( db->xAuth ){
        int rcauth;
        char *zCol = pTo->aCol[pIdx ? pIdx->aiColumn[i] : pTo->iPKey].zName;
        rcauth = sqlite3AuthReadCol(pParse, pTo->zName, zCol, iDb);
        isIgnore = (rcauth==SQLITE_IGNORE);
      }
#endif
    }

    /* Take a shared-cache advisory read-lock on the parent table. Allocate 
    ** a cursor to use to search the unique index on the parent key columns 
    ** in the parent table.  */
................................................................................
    sqlite3TableLock(pParse, iDb, pTo->tnum, 0, pTo->zName);
    pParse->nTab++;

    if( regOld!=0 ){
      /* A row is being removed from the child table. Search for the parent.
      ** If the parent does not exist, removing the child row resolves an 
      ** outstanding foreign key constraint violation. */
      fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regOld, -1,isIgnore);
    }
    if( regNew!=0 ){
      /* A row is being added to the child table. If a parent row cannot
      ** be found, adding the child row has violated the FK constraint. */ 






      fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regNew, +1,isIgnore);
    }

    sqlite3DbFree(db, aiFree);
  }

  /* Loop through all the foreign key constraints that refer to this table.
  ** (the "child" constraints) */
................................................................................
      continue;
    }

    if( !pFKey->isDeferred && !(db->flags & SQLITE_DeferFKs) 
     && !pParse->pToplevel && !pParse->isMultiWrite 
    ){
      assert( regOld==0 && regNew!=0 );
      /* Inserting a single row into a parent table cannot cause an immediate
      ** foreign key violation. So do nothing in this case.  */
      continue;
    }

    if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ){
      if( !isIgnoreErrors || db->mallocFailed ) return;
      continue;
    }
................................................................................
      pItem->pTab->nRef++;
      pItem->iCursor = pParse->nTab++;
  
      if( regNew!=0 ){
        fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regNew, -1);
      }
      if( regOld!=0 ){
        /* If there is a RESTRICT action configured for the current operation
        ** on the parent table of this FK, then throw an exception 
        ** immediately if the FK constraint is violated, even if this is a
        ** deferred trigger. That's what RESTRICT means. To defer checking
        ** the constraint, the FK should specify NO ACTION (represented
        ** using OE_None). NO ACTION is the default.  */
        fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regOld, 1);







      }
      pItem->zName = 0;
      sqlite3SrcListDelete(db, pSrc);
    }
    sqlite3DbFree(db, aiCol);
  }
}







|







 







>
>
>
>







 







<
<
<







 







>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>







 







|







 







|







 







|

|

|
>
>
>
>
>
>
|







 







|
|







 







|
<
<
<
<
<

>
>
>
>
>
>
>







433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
...
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
...
629
630
631
632
633
634
635



636
637
638
639
640
641
642
...
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
...
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
...
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
...
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
...
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
....
1008
1009
1010
1011
1012
1013
1014
1015





1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
    ** incrementing a counter. This is necessary as the VM code is being
    ** generated for will not open a statement transaction.  */
    assert( nIncr==1 );
    sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,
        OE_Abort, 0, P4_STATIC, P5_ConstraintFK);
  }else{
    if( nIncr>0 && pFKey->isDeferred==0 ){
      sqlite3MayAbort(pParse);
    }
    sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
  }

  sqlite3VdbeResolveLabel(v, iOk);
  sqlite3VdbeAddOp1(v, OP_Close, iCur);
}
................................................................................

/*
** This function is called to generate code executed when a row is deleted
** from the parent table of foreign key constraint pFKey and, if pFKey is 
** deferred, when a row is inserted into the same table. When generating
** code for an SQL UPDATE operation, this function may be called twice -
** once to "delete" the old row and once to "insert" the new row.
**
** Parameter nIncr is passed -1 when inserting a row (as this may decrease
** the number of FK violations in the db) or +1 when deleting one (as this
** may increase the number of FK constraint problems).
**
** The code generated by this function scans through the rows in the child
** table that correspond to the parent table row being deleted or inserted.
** For each child row found, one of the following actions is taken:
**
**   Operation | FK type   | Action taken
**   --------------------------------------------------------------------------
................................................................................
  sqlite3ResolveExprNames(&sNameContext, pWhere);

  /* Create VDBE to loop through the entries in pSrc that match the WHERE
  ** clause. If the constraint is not deferred, throw an exception for
  ** each row found. Otherwise, for deferred constraints, increment the
  ** deferred constraint counter by nIncr for each row selected.  */
  pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0, 0, 0);



  sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
  if( pWInfo ){
    sqlite3WhereEnd(pWInfo);
  }

  /* Clean up the WHERE clause constructed above. */
  sqlite3ExprDelete(db, pWhere);
................................................................................
          return 1;
        }
      }
    }
  }
  return 0;
}

/*
** Return true if the parser passed as the first argument is being
** used to code a trigger that is really a "SET NULL" action belonging
** to trigger pFKey.
*/
static int isSetNullAction(Parse *pParse, FKey *pFKey){
  Parse *pTop = sqlite3ParseToplevel(pParse);
  if( pTop->pTriggerPrg ){
    Trigger *p = pTop->pTriggerPrg->pTrigger;
    if( (p==pFKey->apTrigger[0] && pFKey->aAction[0]==OE_SetNull)
     || (p==pFKey->apTrigger[1] && pFKey->aAction[1]==OE_SetNull)
    ){
      return 1;
    }
  }
  return 0;
}

/*
** This function is called when inserting, deleting or updating a row of
** table pTab to generate VDBE code to perform foreign key constraint 
** processing for the operation.
**
** For a DELETE operation, parameter regOld is passed the index of the
................................................................................
  for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){
    Table *pTo;                   /* Parent table of foreign key pFKey */
    Index *pIdx = 0;              /* Index on key columns in pTo */
    int *aiFree = 0;
    int *aiCol;
    int iCol;
    int i;
    int bIgnore = 0;

    if( aChange 
     && sqlite3_stricmp(pTab->zName, pFKey->zTo)!=0
     && fkChildIsModified(pTab, pFKey, aChange, bChngRowid)==0 
    ){
      continue;
    }
................................................................................
      /* Request permission to read the parent key columns. If the 
      ** authorization callback returns SQLITE_IGNORE, behave as if any
      ** values read from the parent table are NULL. */
      if( db->xAuth ){
        int rcauth;
        char *zCol = pTo->aCol[pIdx ? pIdx->aiColumn[i] : pTo->iPKey].zName;
        rcauth = sqlite3AuthReadCol(pParse, pTo->zName, zCol, iDb);
        bIgnore = (rcauth==SQLITE_IGNORE);
      }
#endif
    }

    /* Take a shared-cache advisory read-lock on the parent table. Allocate 
    ** a cursor to use to search the unique index on the parent key columns 
    ** in the parent table.  */
................................................................................
    sqlite3TableLock(pParse, iDb, pTo->tnum, 0, pTo->zName);
    pParse->nTab++;

    if( regOld!=0 ){
      /* A row is being removed from the child table. Search for the parent.
      ** If the parent does not exist, removing the child row resolves an 
      ** outstanding foreign key constraint violation. */
      fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regOld, -1, bIgnore);
    }
    if( regNew!=0 && !isSetNullAction(pParse, pFKey) ){
      /* A row is being added to the child table. If a parent row cannot
      ** be found, adding the child row has violated the FK constraint. 
      **
      ** If this operation is being performed as part of a trigger program
      ** that is actually a "SET NULL" action belonging to this very 
      ** foreign key, then omit this scan altogether. As the child keys
      ** values are guaranteed to be NULL, it is not possible for adding
      ** this row to cause an FK violation. */
      fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regNew, +1, bIgnore);
    }

    sqlite3DbFree(db, aiFree);
  }

  /* Loop through all the foreign key constraints that refer to this table.
  ** (the "child" constraints) */
................................................................................
      continue;
    }

    if( !pFKey->isDeferred && !(db->flags & SQLITE_DeferFKs) 
     && !pParse->pToplevel && !pParse->isMultiWrite 
    ){
      assert( regOld==0 && regNew!=0 );
      /* Inserting a single row into a parent table cannot cause (or fix)
      ** an immediate foreign key violation. So do nothing in this case.  */
      continue;
    }

    if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ){
      if( !isIgnoreErrors || db->mallocFailed ) return;
      continue;
    }
................................................................................
      pItem->pTab->nRef++;
      pItem->iCursor = pParse->nTab++;
  
      if( regNew!=0 ){
        fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regNew, -1);
      }
      if( regOld!=0 ){
        int eAction = pFKey->aAction[aChange!=0];





        fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regOld, 1);
        /* If this is a deferred FK constraint, or a CASCADE or SET NULL
        ** action applies, do not set the may-abort flag on this statement.
        ** The flag may be set on this statement for some other reason, but
        ** not as a result of this FK constraint. */
        if( !pFKey->isDeferred && eAction!=OE_Cascade && eAction!=OE_SetNull ){
          sqlite3MayAbort(pParse);
        }
      }
      pItem->zName = 0;
      sqlite3SrcListDelete(db, pSrc);
    }
    sqlite3DbFree(db, aiCol);
  }
}

Changes to src/vdbeaux.c.

392
393
394
395
396
397
398

399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415





416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
** match, or false otherwise. This function is intended to be used as
** part of an assert statement in the compiler. Similar to:
**
**   assert( sqlite3VdbeAssertMayAbort(pParse->pVdbe, pParse->mayAbort) );
*/
int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
  int hasAbort = 0;

  Op *pOp;
  VdbeOpIter sIter;
  memset(&sIter, 0, sizeof(sIter));
  sIter.v = v;

  while( (pOp = opIterNext(&sIter))!=0 ){
    int opcode = pOp->opcode;
    if( opcode==OP_Destroy || opcode==OP_VUpdate || opcode==OP_VRename 
#ifndef SQLITE_OMIT_FOREIGN_KEY
     || (opcode==OP_FkCounter && pOp->p1==0 && pOp->p2==1) 
#endif
     || ((opcode==OP_Halt || opcode==OP_HaltIfNull) 
      && ((pOp->p1&0xff)==SQLITE_CONSTRAINT && pOp->p2==OE_Abort))
    ){
      hasAbort = 1;
      break;
    }





  }
  sqlite3DbFree(v->db, sIter.apSub);

  /* Return true if hasAbort==mayAbort. Or if a malloc failure occurred.
  ** If malloc failed, then the while() loop above may not have iterated
  ** through all opcodes and hasAbort may be set incorrectly. Return
  ** true for this case to prevent the assert() in the callers frame
  ** from failing.  */
  return ( v->db->mallocFailed || hasAbort==mayAbort );
}
#endif /* SQLITE_DEBUG - the sqlite3AssertMayAbort() function */

/*
** Loop through the program looking for P2 values that are negative
** on jump instructions.  Each such value is a label.  Resolve the
** label by setting the P2 value to its correct non-zero value.







>








<
<
<






>
>
>
>
>








|







392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407



408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
** match, or false otherwise. This function is intended to be used as
** part of an assert statement in the compiler. Similar to:
**
**   assert( sqlite3VdbeAssertMayAbort(pParse->pVdbe, pParse->mayAbort) );
*/
int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
  int hasAbort = 0;
  int hasFkCounter = 0;
  Op *pOp;
  VdbeOpIter sIter;
  memset(&sIter, 0, sizeof(sIter));
  sIter.v = v;

  while( (pOp = opIterNext(&sIter))!=0 ){
    int opcode = pOp->opcode;
    if( opcode==OP_Destroy || opcode==OP_VUpdate || opcode==OP_VRename 



     || ((opcode==OP_Halt || opcode==OP_HaltIfNull) 
      && ((pOp->p1&0xff)==SQLITE_CONSTRAINT && pOp->p2==OE_Abort))
    ){
      hasAbort = 1;
      break;
    }
#ifndef SQLITE_OMIT_FOREIGN_KEY
    if( opcode==OP_FkCounter && pOp->p1==0 && pOp->p2==1 ){
      hasFkCounter = 1;
    }
#endif
  }
  sqlite3DbFree(v->db, sIter.apSub);

  /* Return true if hasAbort==mayAbort. Or if a malloc failure occurred.
  ** If malloc failed, then the while() loop above may not have iterated
  ** through all opcodes and hasAbort may be set incorrectly. Return
  ** true for this case to prevent the assert() in the callers frame
  ** from failing.  */
  return ( v->db->mallocFailed || hasAbort==mayAbort || hasFkCounter );
}
#endif /* SQLITE_DEBUG - the sqlite3AssertMayAbort() function */

/*
** Loop through the program looking for P2 values that are negative
** on jump instructions.  Each such value is a label.  Resolve the
** label by setting the P2 value to its correct non-zero value.

Added test/fkey8.test.











































































































































































>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
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
# 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.
#
# This file implements tests for foreign keys.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix fkey8

ifcapable {!foreignkey} {
  finish_test
  return
}
do_execsql_test 1.0 { PRAGMA foreign_keys = 1; }


foreach {tn use_stmt sql schema} {
  1   1 "DELETE FROM p1" {
    CREATE TABLE p1(a PRIMARY KEY);
    CREATE TABLE c1(b REFERENCES p1);
  }

  2.1     0 "DELETE FROM p1" {
    CREATE TABLE p1(a PRIMARY KEY);
    CREATE TABLE c1(b REFERENCES p1 ON DELETE CASCADE);
  }
  2.2   0 "DELETE FROM p1" {
    CREATE TABLE p1(a PRIMARY KEY);
    CREATE TABLE c1(b REFERENCES p1 ON DELETE SET NULL);
  }
  2.3   1 "DELETE FROM p1" {
    CREATE TABLE p1(a PRIMARY KEY);
    CREATE TABLE c1(b REFERENCES p1 ON DELETE SET DEFAULT);
  }

  3   1 "DELETE FROM p1" {
    CREATE TABLE p1(a PRIMARY KEY);
    CREATE TABLE c1(b REFERENCES p1 ON DELETE CASCADE);
    CREATE TRIGGER ct1 AFTER DELETE ON c1 BEGIN
      INSERT INTO p1 VALUES('x');
    END;
  }

  4   1 "DELETE FROM p1" {
    CREATE TABLE p1(a PRIMARY KEY);
    CREATE TABLE c1(b REFERENCES p1 ON DELETE CASCADE, c PRIMARY KEY);
    CREATE TABLE cc1(d REFERENCES c1);
  }

  5.1   0 "DELETE FROM p1" {
    CREATE TABLE p1(a PRIMARY KEY);
    CREATE TABLE c1(b REFERENCES p1 ON DELETE CASCADE, c PRIMARY KEY);
    CREATE TABLE cc1(d REFERENCES c1 ON DELETE CASCADE);
  }
  5.2   0 "DELETE FROM p1" {
    CREATE TABLE p1(a PRIMARY KEY);
    CREATE TABLE c1(b REFERENCES p1 ON DELETE CASCADE, c PRIMARY KEY);
    CREATE TABLE cc1(d REFERENCES c1 ON DELETE SET NULL);
  }

} {
  drop_all_tables
  do_test 1.$tn {
    execsql $schema
    set stmt [sqlite3_prepare_v2 db $sql -1 dummy]
    set ret [uses_stmt_journal $stmt]
    sqlite3_finalize $stmt
    set ret
  } $use_stmt
}




finish_test