/ Check-in [3a695263]
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:Simplification to the logic used to decide between OP_Seek and OP_NotExists. Use OP_NotExists for both DELETE and UPDATE.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 3a695263183303e3f64eb2320752d0fdef53eaf2
User & Date: drh 2016-05-06 20:23:12
Context
2016-05-07
12:15
Fix typo in the intpkey-17.2 test. check-in: a45fda65 user: drh tags: trunk
2016-05-06
20:23
Simplification to the logic used to decide between OP_Seek and OP_NotExists. Use OP_NotExists for both DELETE and UPDATE. check-in: 3a695263 user: drh tags: trunk
18:47
Corrections to comments on the whereScanInit() interface. check-in: ab7ab415 user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/update.c.

348
349
350
351
352
353
354
355

356
357
358
359
360
361
362
#endif

  /* Begin the database scan
  */
  if( HasRowid(pTab) ){
    sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
    pWInfo = sqlite3WhereBegin(
        pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, iIdxCur

    );
    if( pWInfo==0 ) goto update_cleanup;
    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
  
    /* Remember the rowid of every item to be updated.
    */
    sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);







|
>







348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
#endif

  /* Begin the database scan
  */
  if( HasRowid(pTab) ){
    sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
    pWInfo = sqlite3WhereBegin(
        pParse, pTabList, pWhere, 0, 0,
            WHERE_ONEPASS_DESIRED | WHERE_SEEK_TABLE, iIdxCur
    );
    if( pWInfo==0 ) goto update_cleanup;
    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
  
    /* Remember the rowid of every item to be updated.
    */
    sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);

Changes to src/wherecode.c.

1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336

    /* Seek the table cursor, if required */
    disableTerm(pLevel, pRangeStart);
    disableTerm(pLevel, pRangeEnd);
    if( omitTable ){
      /* pIdx is a covering index.  No need to access the main table. */
    }else if( HasRowid(pIdx->pTable) ){
      if( pWInfo->eOnePass!=ONEPASS_OFF
       || (pWInfo->wctrlFlags & WHERE_SEEK_TABLE)!=0
      ){
        iRowidReg = ++pParse->nMem;
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
        sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
        sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowidReg);
        VdbeCoverage(v);
      }else{
        codeDeferredSeek(pWInfo, pIdx, iCur, iIdxCur);







<
|
<







1320
1321
1322
1323
1324
1325
1326

1327

1328
1329
1330
1331
1332
1333
1334

    /* Seek the table cursor, if required */
    disableTerm(pLevel, pRangeStart);
    disableTerm(pLevel, pRangeEnd);
    if( omitTable ){
      /* pIdx is a covering index.  No need to access the main table. */
    }else if( HasRowid(pIdx->pTable) ){

      if( (pWInfo->wctrlFlags & WHERE_SEEK_TABLE)!=0 ){

        iRowidReg = ++pParse->nMem;
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
        sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
        sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowidReg);
        VdbeCoverage(v);
      }else{
        codeDeferredSeek(pWInfo, pIdx, iCur, iIdxCur);

Changes to test/intpkey.test.

627
628
629
630
631
632
633
634
635
636
637






638
639
  DELETE FROM t17 WHERE x=99 OR x<130;
  SELECT * FROM t17;
} {248 giraffe}
do_execsql_test intpkey-17.1 {
  DROP INDEX t17x;
  DELETE FROM t17;
  INSERT INTO t17(x,y) VALUES(123,'elephant'),(248,'giraffe');
  CREATE INDEX t17x ON t17(abs(x));
  DELETE FROM t17 WHERE abs(x) IS NULL OR abs(x)<130;
  SELECT * FROM t17;
} {248 giraffe}







finish_test







|



>
>
>
>
>
>


627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
  DELETE FROM t17 WHERE x=99 OR x<130;
  SELECT * FROM t17;
} {248 giraffe}
do_execsql_test intpkey-17.1 {
  DROP INDEX t17x;
  DELETE FROM t17;
  INSERT INTO t17(x,y) VALUES(123,'elephant'),(248,'giraffe');
  CREATE UNIQUE INDEX t17x ON t17(abs(x));
  DELETE FROM t17 WHERE abs(x) IS NULL OR abs(x)<130;
  SELECT * FROM t17;
} {248 giraffe}
do_execsql_test intpkey-17.2 {
  DELETE FROM t17;
  INSERT INTO t17(x,y) VALUES(123,'elephant'),(248,'giraffe');
  UPDATE FROM t17 SET y='ostrich' WHERE abs(x)=248;
  SELECT * FROM t17 ORDER BY +x;
} {123 elephant 248 ostrich}

finish_test