diff options
Diffstat (limited to 'src/backend/optimizer/plan/planmain.c')
| -rw-r--r-- | src/backend/optimizer/plan/planmain.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/src/backend/optimizer/plan/planmain.c b/src/backend/optimizer/plan/planmain.c index 5e5da6cda4f..081a7c9cebd 100644 --- a/src/backend/optimizer/plan/planmain.c +++ b/src/backend/optimizer/plan/planmain.c @@ -14,7 +14,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/plan/planmain.c,v 1.108 2008/08/03 19:10:52 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/plan/planmain.c,v 1.109 2008/08/05 02:43:17 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -66,9 +66,9 @@ * PlannerInfo field and not a passed parameter is that the low-level routines * in indxpath.c need to see it.) * - * Note: the PlannerInfo node also includes group_pathkeys and sort_pathkeys, - * which like query_pathkeys need to be canonicalized once the info is - * available. + * Note: the PlannerInfo node also includes group_pathkeys, distinct_pathkeys, + * and sort_pathkeys, which like query_pathkeys need to be canonicalized once + * the info is available. * * tuple_fraction is interpreted as follows: * 0: expect all tuples to be retrieved (normal case) @@ -120,6 +120,8 @@ query_planner(PlannerInfo *root, List *tlist, root->query_pathkeys); root->group_pathkeys = canonicalize_pathkeys(root, root->group_pathkeys); + root->distinct_pathkeys = canonicalize_pathkeys(root, + root->distinct_pathkeys); root->sort_pathkeys = canonicalize_pathkeys(root, root->sort_pathkeys); return; @@ -237,10 +239,12 @@ query_planner(PlannerInfo *root, List *tlist, /* * We have completed merging equivalence sets, so it's now possible to * convert the requested query_pathkeys to canonical form. Also - * canonicalize the groupClause and sortClause pathkeys for use later. + * canonicalize the groupClause, distinctClause and sortClause pathkeys + * for use later. */ root->query_pathkeys = canonicalize_pathkeys(root, root->query_pathkeys); root->group_pathkeys = canonicalize_pathkeys(root, root->group_pathkeys); + root->distinct_pathkeys = canonicalize_pathkeys(root, root->distinct_pathkeys); root->sort_pathkeys = canonicalize_pathkeys(root, root->sort_pathkeys); /* @@ -286,9 +290,11 @@ query_planner(PlannerInfo *root, List *tlist, /* * If both GROUP BY and ORDER BY are specified, we will need two * levels of sort --- and, therefore, certainly need to read all the - * tuples --- unless ORDER BY is a subset of GROUP BY. + * tuples --- unless ORDER BY is a subset of GROUP BY. Likewise if + * we have both DISTINCT and GROUP BY. */ - if (!pathkeys_contained_in(root->sort_pathkeys, root->group_pathkeys)) + if (!pathkeys_contained_in(root->sort_pathkeys, root->group_pathkeys) || + !pathkeys_contained_in(root->distinct_pathkeys, root->group_pathkeys)) tuple_fraction = 0.0; } else if (parse->hasAggs || root->hasHavingQual) |