diff options
Diffstat (limited to 'src/backend/optimizer/plan/subselect.c')
| -rw-r--r-- | src/backend/optimizer/plan/subselect.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c index b02fcb9bfe7..9a8f738c9d0 100644 --- a/src/backend/optimizer/plan/subselect.c +++ b/src/backend/optimizer/plan/subselect.c @@ -200,7 +200,7 @@ make_subplan(PlannerInfo *root, Query *orig_subquery, * XXX If an ANY subplan is uncorrelated, build_subplan may decide to hash * its output. In that case it would've been better to specify full * retrieval. At present, however, we can only check hashability after - * we've made the subplan :-(. (Determining whether it'll fit in work_mem + * we've made the subplan :-(. (Determining whether it'll fit in hash_mem * is the really hard part.) Therefore, we don't want to be too * optimistic about the percentage of tuples retrieved, for fear of * selecting a plan that's bad for the materialization case. @@ -278,7 +278,7 @@ make_subplan(PlannerInfo *root, Query *orig_subquery, plan = create_plan(subroot, best_path); - /* Now we can check if it'll fit in work_mem */ + /* Now we can check if it'll fit in hash_mem */ /* XXX can we check this at the Path stage? */ if (subplan_is_hashable(plan)) { @@ -716,16 +716,17 @@ static bool subplan_is_hashable(Plan *plan) { double subquery_size; + int hash_mem = get_hash_mem(); /* - * The estimated size of the subquery result must fit in work_mem. (Note: + * The estimated size of the subquery result must fit in hash_mem. (Note: * we use heap tuple overhead here even though the tuples will actually be * stored as MinimalTuples; this provides some fudge factor for hashtable * overhead.) */ subquery_size = plan->plan_rows * (MAXALIGN(plan->plan_width) + MAXALIGN(SizeofHeapTupleHeader)); - if (subquery_size > work_mem * 1024L) + if (subquery_size > hash_mem * 1024L) return false; return true; |