diff options
Diffstat (limited to 'src/backend/optimizer/plan/createplan.c')
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 40 |
1 files changed, 3 insertions, 37 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index 8d4c836fa55..8e20ae302e1 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.86 2000/02/18 23:47:21 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.87 2000/03/22 22:08:34 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -314,7 +314,6 @@ create_indexscan_node(Query *root, List *ixid; IndexScan *scan_node; bool lossy = false; - double plan_rows; /* there should be exactly one base rel involved... */ Assert(length(best_path->path.parent->relids) == 1); @@ -350,20 +349,7 @@ create_indexscan_node(Query *root, * given by scan_clauses, there will normally be some duplications * between the lists. We get rid of the duplicates, then add back * if lossy. - * - * If this indexscan is a nestloop-join inner indexscan (as indicated - * by having nonempty joinrelids), then it uses indexqual conditions - * that are not part of the relation's restriction clauses. The rows - * estimate stored in the relation's RelOptInfo will be an overestimate - * because it did not take these extra conditions into account. So, - * in this case we recompute the selectivity of the whole scan --- - * considering both indexqual and qpqual --- rather than using the - * RelOptInfo's rows value. Since clausesel.c assumes it's working on - * minimized (no duplicates) expressions, we have to do that while we - * have the duplicate-free qpqual available. */ - plan_rows = best_path->path.parent->rows; /* OK unless nestloop inner */ - if (length(indxqual) > 1) { /* @@ -383,15 +369,6 @@ create_indexscan_node(Query *root, qpqual = set_difference(scan_clauses, lcons(indxqual_expr, NIL)); - if (best_path->joinrelids) - { - /* recompute output row estimate using all available quals */ - plan_rows = best_path->path.parent->tuples * - clauselist_selectivity(root, - lcons(indxqual_expr, qpqual), - baserelid); - } - if (lossy) qpqual = lappend(qpqual, copyObject(indxqual_expr)); } @@ -404,15 +381,6 @@ create_indexscan_node(Query *root, qpqual = set_difference(scan_clauses, indxqual_list); - if (best_path->joinrelids) - { - /* recompute output row estimate using all available quals */ - plan_rows = best_path->path.parent->tuples * - clauselist_selectivity(root, - nconc(listCopy(indxqual_list), qpqual), - baserelid); - } - if (lossy) qpqual = nconc(qpqual, (List *) copyObject(indxqual_list)); } @@ -433,10 +401,8 @@ create_indexscan_node(Query *root, best_path->indexscandir); copy_path_costsize(&scan_node->scan.plan, &best_path->path); - /* set up rows estimate (just to make EXPLAIN output reasonable) */ - if (plan_rows < 1.0) - plan_rows = 1.0; - scan_node->scan.plan.plan_rows = plan_rows; + /* use the indexscan-specific rows estimate, not the parent rel's */ + scan_node->scan.plan.plan_rows = best_path->rows; return scan_node; } |