/ Check-in [545bb336]
Login

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

Overview
Comment:Factor an invariant out the loop termination condition for the ORDER BY satisfied-by-index analyzer routine.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 545bb33688663066cf3f09e4cdc4d5cfe59fb8db
User & Date: drh 2012-10-02 01:46:48
Context
2012-10-02
14:11
Only continue an ORDER BY optimization into inner loops if the equality constraints on the inner loop match terms of an outer ordered index that are actually used by the ORDER BY clause. check-in: b0e7b4df user: drh tags: trunk
01:46
Factor an invariant out the loop termination condition for the ORDER BY satisfied-by-index analyzer routine. check-in: 545bb336 user: drh tags: trunk
01:25
Make sure the outer loop cursor numbers are recorded in time for them to be used by the ORDER BY optimizer. check-in: 351dc8d9 user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/where.c.

2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869

2870
2871
2872
2873
2874
2875
2876
  ** the index.
  **
  ** Note that indices have pIdx->nColumn regular columns plus
  ** one additional column containing the rowid.  The rowid column
  ** of the index is also allowed to match against the ORDER BY
  ** clause.
  */
  for(i=0,j=nPriorSat,pTerm=&pOrderBy->a[j]; j<nTerm && i<=pIdx->nColumn; i++){
    Expr *pExpr;       /* The expression of the ORDER BY pTerm */
    CollSeq *pColl;    /* The collating sequence of pExpr */
    int termSortOrder; /* Sort order for this term */
    int iColumn;       /* The i-th column of the index.  -1 for rowid */
    int iSortOrder;    /* 1 for DESC, 0 for ASC on the i-th index term */
    const char *zColl; /* Name of the collating sequence for i-th index term */


    pExpr = pTerm->pExpr;
    if( pExpr->op!=TK_COLUMN || pExpr->iTable!=base ){
      /* Can not use an index sort on anything that is not a column in the
      ** left-most table of the FROM clause */
      break;
    }
    pColl = sqlite3ExprCollSeq(pParse, pExpr);







|







>







2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
  ** the index.
  **
  ** Note that indices have pIdx->nColumn regular columns plus
  ** one additional column containing the rowid.  The rowid column
  ** of the index is also allowed to match against the ORDER BY
  ** clause.
  */
  for(i=0,j=nPriorSat,pTerm=&pOrderBy->a[j]; j<nTerm; i++){
    Expr *pExpr;       /* The expression of the ORDER BY pTerm */
    CollSeq *pColl;    /* The collating sequence of pExpr */
    int termSortOrder; /* Sort order for this term */
    int iColumn;       /* The i-th column of the index.  -1 for rowid */
    int iSortOrder;    /* 1 for DESC, 0 for ASC on the i-th index term */
    const char *zColl; /* Name of the collating sequence for i-th index term */

    assert( i<=pIdx->nColumn );
    pExpr = pTerm->pExpr;
    if( pExpr->op!=TK_COLUMN || pExpr->iTable!=base ){
      /* Can not use an index sort on anything that is not a column in the
      ** left-most table of the FROM clause */
      break;
    }
    pColl = sqlite3ExprCollSeq(pParse, pExpr);