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Overview
Comment:Small size reduction and performance enhancement in whereScanInit().
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SHA1: c23f5ef337533c1ec6e3ba78a2910352181cc9ee
User & Date: drh 2016-10-26 18:41:43
Context
2016-10-27
01:02
Make sure left-join markings are transferred to the virtual scalar subexpressions when decomposing a vector comparison in the ON clause of a LEFT JOIN. Fix for ticket [fef4bb4bd9185ec8f]. check-in: 619f5cc7 user: drh tags: trunk
2016-10-26
18:41
Small size reduction and performance enhancement in whereScanInit(). check-in: c23f5ef3 user: drh tags: trunk
17:57
Small size reduction and performance improvement in whereScanNext(). check-in: d861ee17 user: drh tags: trunk
Changes
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Changes to src/where.c.

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  WhereTerm *pTerm;    /* The term being tested */
  int k = pScan->k;    /* Where to start scanning */

  assert( pScan->iEquiv<=pScan->nEquiv );
  pWC = pScan->pWC;
  while(1){
    iColumn = pScan->aiColumn[pScan->iEquiv-1];
    if( iColumn==XN_EXPR && pScan->pIdxExpr==0 ) return 0;
    iCur = pScan->aiCur[pScan->iEquiv-1];
    assert( pWC!=0 );
    do{
      for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
        if( pTerm->leftCursor==iCur
         && pTerm->u.leftColumn==iColumn
         && (iColumn!=XN_EXPR
................................................................................
  WhereScan *pScan,       /* The WhereScan object being initialized */
  WhereClause *pWC,       /* The WHERE clause to be scanned */
  int iCur,               /* Cursor to scan for */
  int iColumn,            /* Column to scan for */
  u32 opMask,             /* Operator(s) to scan for */
  Index *pIdx             /* Must be compatible with this index */
){
  int j = 0;

  /* memset(pScan, 0, sizeof(*pScan)); */
  pScan->pOrigWC = pWC;
  pScan->pWC = pWC;
  pScan->pIdxExpr = 0;


  if( pIdx ){
    j = iColumn;
    iColumn = pIdx->aiColumn[j];

    if( iColumn==XN_EXPR ) pScan->pIdxExpr = pIdx->aColExpr->a[j].pExpr;
    if( iColumn==pIdx->pTable->iPKey ) iColumn = XN_ROWID;
  }

  if( pIdx && iColumn>=0 ){
    pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
    pScan->zCollName = pIdx->azColl[j];
  }else{
    pScan->idxaff = 0;
    pScan->zCollName = 0;



  }
  pScan->opMask = opMask;
  pScan->k = 0;
  pScan->aiCur[0] = iCur;
  pScan->aiColumn[0] = iColumn;
  pScan->nEquiv = 1;
  pScan->iEquiv = 1;







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  WhereTerm *pTerm;    /* The term being tested */
  int k = pScan->k;    /* Where to start scanning */

  assert( pScan->iEquiv<=pScan->nEquiv );
  pWC = pScan->pWC;
  while(1){
    iColumn = pScan->aiColumn[pScan->iEquiv-1];

    iCur = pScan->aiCur[pScan->iEquiv-1];
    assert( pWC!=0 );
    do{
      for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
        if( pTerm->leftCursor==iCur
         && pTerm->u.leftColumn==iColumn
         && (iColumn!=XN_EXPR
................................................................................
  WhereScan *pScan,       /* The WhereScan object being initialized */
  WhereClause *pWC,       /* The WHERE clause to be scanned */
  int iCur,               /* Cursor to scan for */
  int iColumn,            /* Column to scan for */
  u32 opMask,             /* Operator(s) to scan for */
  Index *pIdx             /* Must be compatible with this index */
){



  pScan->pOrigWC = pWC;
  pScan->pWC = pWC;
  pScan->pIdxExpr = 0;
  pScan->idxaff = 0;
  pScan->zCollName = 0;
  if( pIdx ){
    int j = iColumn;
    iColumn = pIdx->aiColumn[j];
    if( iColumn==XN_EXPR ){
      pScan->pIdxExpr = pIdx->aColExpr->a[j].pExpr;
    }else if( iColumn==pIdx->pTable->iPKey ){

      iColumn = XN_ROWID;
    }else if( iColumn>=0 ){
      pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
      pScan->zCollName = pIdx->azColl[j];



    }
  }else if( iColumn==XN_EXPR ){
    return 0;
  }
  pScan->opMask = opMask;
  pScan->k = 0;
  pScan->aiCur[0] = iCur;
  pScan->aiColumn[0] = iColumn;
  pScan->nEquiv = 1;
  pScan->iEquiv = 1;