diff options
Diffstat (limited to 'src/backend/optimizer/plan/planner.c')
| -rw-r--r-- | src/backend/optimizer/plan/planner.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index 620888cbb86..6324bce2403 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -968,6 +968,7 @@ grouping_planner(PlannerInfo *root, double tuple_fraction) { /* No set operations, do regular planning */ List *sub_tlist; + double sub_limit_tuples; AttrNumber *groupColIdx = NULL; bool need_tlist_eval = true; QualCost tlist_cost; @@ -1120,12 +1121,27 @@ grouping_planner(PlannerInfo *root, double tuple_fraction) root->query_pathkeys = NIL; /* + * Figure out whether there's a hard limit on the number of rows that + * query_planner's result subplan needs to return. Even if we know a + * hard limit overall, it doesn't apply if the query has any + * grouping/aggregation operations. + */ + if (parse->groupClause || + parse->distinctClause || + parse->hasAggs || + parse->hasWindowFuncs || + root->hasHavingQual) + sub_limit_tuples = -1.0; + else + sub_limit_tuples = limit_tuples; + + /* * Generate the best unsorted and presorted paths for this Query (but * note there may not be any presorted path). query_planner will also * estimate the number of groups in the query, and canonicalize all * the pathkeys. */ - query_planner(root, sub_tlist, tuple_fraction, limit_tuples, + query_planner(root, sub_tlist, tuple_fraction, sub_limit_tuples, &cheapest_path, &sorted_path, &dNumGroups); /* |