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Overview
Comment:Avoid superfluous cursor seeks in "INSERT OR REPLACE" statements.
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SHA1: bec5b6d4d083556d111a89186b4f7b35b5e7cebf
User & Date: dan 2016-11-08 19:22:32.125
References
2019-10-24
19:35
Correction to check-in [bec5b6d4d083556d] so that it detects *all* triggers that might perturb the insertion cursor. Ticket [50c09fc2cf0d91ce]. (check-in: 521f1d3628 user: drh tags: trunk)
19:29 • New ticket [50c09fc2cf] Crash on REPLACE INTO of a table with an AFTER DELETE trigger.. (artifact: 6efcc42979 user: drh)
Context
2016-11-09
00:57
Remove the "experimental" marking from the sqlite3_preupdate interfaces. But be sure all the interface definitions are within documentation. (check-in: d6dd2ad35e user: drh tags: trunk)
00:10
Enhance the OP_IdxInsert opcode to optionally accept unpacked key material. (check-in: 89d958abba user: drh tags: unpacked-IdxInsert)
2016-11-08
19:22
Avoid superfluous cursor seeks in "INSERT OR REPLACE" statements. (check-in: bec5b6d4d0 user: dan tags: trunk)
17:19
Avoid generating OP_TableLock unnecessary instructions on btrees that are not sharable. (check-in: 8cb8516d20 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/insert.c.
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      sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns, pVTab, P4_VTAB);
      sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
      sqlite3MayAbort(pParse);
    }else
#endif
    {
      int isReplace;    /* Set to true if constraints may cause a replace */

      sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
          regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace, 0
      );
      sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);












      sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
                               regIns, aRegIdx, 0, appendFlag, isReplace==0);

    }
  }

  /* Update the count of rows that are inserted
  */
  if( (db->flags & SQLITE_CountRows)!=0 ){
    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);








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      sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns, pVTab, P4_VTAB);
      sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
      sqlite3MayAbort(pParse);
    }else
#endif
    {
      int isReplace;    /* Set to true if constraints may cause a replace */
      int bUseSeek;     /* True to use OPFLAG_SEEKRESULT */
      sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
          regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace, 0
      );
      sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);

      /* Set the OPFLAG_USESEEKRESULT flag if either (a) there are no REPLACE
      ** constraints or (b) there are no triggers and this table is not a
      ** parent table in a foreign key constraint. It is safe to set the
      ** flag in the second case as if any REPLACE constraint is hit, an
      ** OP_Delete or OP_IdxDelete instruction will be executed on each 
      ** cursor that is disturbed. And these instructions both clear the
      ** VdbeCursor.seekResult variable, disabling the OPFLAG_USESEEKRESULT
      ** functionality.  */
      bUseSeek = (isReplace==0 || (pTrigger==0 &&
          ((db->flags & SQLITE_ForeignKeys)==0 || sqlite3FkReferences(pTab)==0)
      ));
      sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
          regIns, aRegIdx, 0, appendFlag, bUseSeek
      );
    }
  }

  /* Update the count of rows that are inserted
  */
  if( (db->flags & SQLITE_CountRows)!=0 ){
    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
︙︙
Changes to src/vdbe.c.
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      nExtraDelete--;
    }
  }
#endif

  rc = sqlite3BtreeDelete(pC->uc.pCursor, pOp->p5);
  pC->cacheStatus = CACHE_STALE;

  if( rc ) goto abort_due_to_error;

  /* Invoke the update-hook if required. */
  if( opflags & OPFLAG_NCHANGE ){
    p->nChange++;
    if( db->xUpdateCallback && HasRowid(pTab) ){
      db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, pTab->zName,








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      nExtraDelete--;
    }
  }
#endif

  rc = sqlite3BtreeDelete(pC->uc.pCursor, pOp->p5);
  pC->cacheStatus = CACHE_STALE;
  pC->seekResult = 0;
  if( rc ) goto abort_due_to_error;

  /* Invoke the update-hook if required. */
  if( opflags & OPFLAG_NCHANGE ){
    p->nChange++;
    if( db->xUpdateCallback && HasRowid(pTab) ){
      db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, pTab->zName,
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  if( rc ) goto abort_due_to_error;
  if( res==0 ){
    rc = sqlite3BtreeDelete(pCrsr, BTREE_AUXDELETE);
    if( rc ) goto abort_due_to_error;
  }
  assert( pC->deferredMoveto==0 );
  pC->cacheStatus = CACHE_STALE;

  break;
}

/* Opcode: Seek P1 * P3 P4 *
** Synopsis: Move P3 to P1.rowid
**
** P1 is an open index cursor and P3 is a cursor on the corresponding








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  if( rc ) goto abort_due_to_error;
  if( res==0 ){
    rc = sqlite3BtreeDelete(pCrsr, BTREE_AUXDELETE);
    if( rc ) goto abort_due_to_error;
  }
  assert( pC->deferredMoveto==0 );
  pC->cacheStatus = CACHE_STALE;
  pC->seekResult = 0;
  break;
}

/* Opcode: Seek P1 * P3 P4 *
** Synopsis: Move P3 to P1.rowid
**
** P1 is an open index cursor and P3 is a cursor on the corresponding
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