diff options
Diffstat (limited to 'src/backend/optimizer/plan/planagg.c')
| -rw-r--r-- | src/backend/optimizer/plan/planagg.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/src/backend/optimizer/plan/planagg.c b/src/backend/optimizer/plan/planagg.c index 9330908cbf1..e0e357960f2 100644 --- a/src/backend/optimizer/plan/planagg.c +++ b/src/backend/optimizer/plan/planagg.c @@ -137,8 +137,8 @@ preprocess_minmax_aggregates(PlannerInfo *root) return; /* - * Scan the tlist and HAVING qual to find all the aggregates and verify - * all are MIN/MAX aggregates. Stop as soon as we find one that isn't. + * Examine all the aggregates and verify all are MIN/MAX aggregates. Stop + * as soon as we find one that isn't. */ aggs_list = NIL; if (!can_minmax_aggs(root, &aggs_list)) @@ -227,24 +227,24 @@ preprocess_minmax_aggregates(PlannerInfo *root) /* * can_minmax_aggs - * Walk through all the aggregates in the query, and check - * if they are all MIN/MAX aggregates. If so, build a list of the - * distinct aggregate calls in the tree. + * Examine all the aggregates in the query, and check if they are + * all MIN/MAX aggregates. If so, build a list of MinMaxAggInfo + * nodes for them. * * Returns false if a non-MIN/MAX aggregate is found, true otherwise. - * - * This does not descend into subqueries, and so should be used only after - * reduction of sublinks to subplans. There mustn't be outer-aggregate - * references either. */ static bool can_minmax_aggs(PlannerInfo *root, List **context) { ListCell *lc; + /* + * This function used to have to scan the query for itself, but now we can + * just thumb through the AggInfo list made by preprocess_aggrefs. + */ foreach(lc, root->agginfos) { - AggInfo *agginfo = (AggInfo *) lfirst(lc); + AggInfo *agginfo = lfirst_node(AggInfo, lc); Aggref *aggref = agginfo->representative_aggref; Oid aggsortop; TargetEntry *curTarget; |