From 553a147b4566e4f6da28e2f7dd2c9759371afd7b Mon Sep 17 00:00:00 2001 From: Ashutosh Bapat Date: Mon, 24 Jul 2023 20:20:53 +0530 Subject: [PATCH 2/2] Reduce memory used by child SpecialJoinInfo The SpecialJoinInfo applicable to a child join is computed by translating the same applicable to the parent join in try_partitionwise_join(). The child SpecialJoinInfo is not needed once the child join RelOptInfo is created and paths are added to it. Use a local variable to hold child SpecialJoinInfo so that it doesn't need memory allocated separately. Also free the memory allocated to various Bitmapsets in SpecialJoinInfo. Those are not referenced anywhere. But we do not free the memory allocated to expression trees of operator OID list since those may be referenced in paths or other objects. --- src/backend/optimizer/path/joinrels.c | 70 +++++++++++++++++++-------- 1 file changed, 50 insertions(+), 20 deletions(-) diff --git a/src/backend/optimizer/path/joinrels.c b/src/backend/optimizer/path/joinrels.c index 015a0b3cbe..5cf32f8b07 100644 --- a/src/backend/optimizer/path/joinrels.c +++ b/src/backend/optimizer/path/joinrels.c @@ -42,9 +42,11 @@ static void try_partitionwise_join(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, RelOptInfo *joinrel, SpecialJoinInfo *parent_sjinfo, List *parent_restrictlist); -static SpecialJoinInfo *build_child_join_sjinfo(PlannerInfo *root, - SpecialJoinInfo *parent_sjinfo, - Relids left_relids, Relids right_relids); +static void build_child_join_sjinfo(PlannerInfo *root, + SpecialJoinInfo *parent_sjinfo, + Relids left_relids, Relids right_relids, + SpecialJoinInfo *child_sjinfo); +static void free_child_sjinfo_members(SpecialJoinInfo *child_sjinfo); static void compute_partition_bounds(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, RelOptInfo *joinrel, SpecialJoinInfo *parent_sjinfo, @@ -1540,7 +1542,7 @@ try_partitionwise_join(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, RelOptInfo *child_rel2; bool rel1_empty; bool rel2_empty; - SpecialJoinInfo *child_sjinfo; + SpecialJoinInfo child_sjinfo; List *child_restrictlist; RelOptInfo *child_joinrel; AppendRelInfo **appinfos; @@ -1635,9 +1637,8 @@ try_partitionwise_join(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, * Construct SpecialJoinInfo from parent join relations's * SpecialJoinInfo. */ - child_sjinfo = build_child_join_sjinfo(root, parent_sjinfo, - child_rel1->relids, - child_rel2->relids); + build_child_join_sjinfo(root, parent_sjinfo, child_rel1->relids, + child_rel2->relids, &child_sjinfo); /* Find the AppendRelInfo structures */ appinfos = find_appinfos_by_relids(root, @@ -1660,7 +1661,7 @@ try_partitionwise_join(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, { child_joinrel = build_child_join_rel(root, child_rel1, child_rel2, joinrel, child_restrictlist, - child_sjinfo); + &child_sjinfo); joinrel->part_rels[cnt_parts] = child_joinrel; joinrel->live_parts = bms_add_member(joinrel->live_parts, cnt_parts); joinrel->all_partrels = bms_add_members(joinrel->all_partrels, @@ -1674,10 +1675,11 @@ try_partitionwise_join(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, /* And make paths for the child join */ populate_joinrel_with_paths(root, child_rel1, child_rel2, - child_joinrel, child_sjinfo, + child_joinrel, &child_sjinfo, child_restrictlist); pfree(appinfos); + free_child_sjinfo_members(&child_sjinfo); } } @@ -1685,43 +1687,71 @@ try_partitionwise_join(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, * Construct the SpecialJoinInfo for a child-join by translating * SpecialJoinInfo for the join between parents. left_relids and right_relids * are the relids of left and right side of the join respectively. + * + * If translations are added or removed from this function, consider freeing + * the translated objects in free_child_sjinfo_members() appropriately. */ -static SpecialJoinInfo * +static void build_child_join_sjinfo(PlannerInfo *root, SpecialJoinInfo *parent_sjinfo, - Relids left_relids, Relids right_relids) + Relids left_relids, Relids right_relids, + SpecialJoinInfo *child_sjinfo) { - SpecialJoinInfo *sjinfo = makeNode(SpecialJoinInfo); AppendRelInfo **left_appinfos; int left_nappinfos; AppendRelInfo **right_appinfos; int right_nappinfos; - memcpy(sjinfo, parent_sjinfo, sizeof(SpecialJoinInfo)); + memcpy(child_sjinfo, parent_sjinfo, sizeof(SpecialJoinInfo)); left_appinfos = find_appinfos_by_relids(root, left_relids, &left_nappinfos); right_appinfos = find_appinfos_by_relids(root, right_relids, &right_nappinfos); - sjinfo->min_lefthand = adjust_child_relids(sjinfo->min_lefthand, + child_sjinfo->min_lefthand = adjust_child_relids(child_sjinfo->min_lefthand, left_nappinfos, left_appinfos); - sjinfo->min_righthand = adjust_child_relids(sjinfo->min_righthand, + child_sjinfo->min_righthand = adjust_child_relids(child_sjinfo->min_righthand, right_nappinfos, right_appinfos); - sjinfo->syn_lefthand = adjust_child_relids(sjinfo->syn_lefthand, + child_sjinfo->syn_lefthand = adjust_child_relids(child_sjinfo->syn_lefthand, left_nappinfos, left_appinfos); - sjinfo->syn_righthand = adjust_child_relids(sjinfo->syn_righthand, + child_sjinfo->syn_righthand = adjust_child_relids(child_sjinfo->syn_righthand, right_nappinfos, right_appinfos); + /* + * commute_above and commute_below relids contain only OJ relids which do + * not need any translation. + */ + /* outer-join relids need no adjustment */ - sjinfo->semi_rhs_exprs = (List *) adjust_appendrel_attrs(root, - (Node *) sjinfo->semi_rhs_exprs, + child_sjinfo->semi_rhs_exprs = (List *) adjust_appendrel_attrs(root, + (Node *) child_sjinfo->semi_rhs_exprs, right_nappinfos, right_appinfos); pfree(left_appinfos); pfree(right_appinfos); +} - return sjinfo; +/* + * free_child_sjinfo_members + * Free memory consumed by members of a child SpecialJoinInfo. + */ +static void +free_child_sjinfo_members(SpecialJoinInfo *child_sjinfo) +{ + /* + * The relids are used only for comparison and their references are not + * stored anywhere. Free those. + */ + bms_free(child_sjinfo->min_lefthand); + bms_free(child_sjinfo->min_righthand); + bms_free(child_sjinfo->syn_lefthand); + bms_free(child_sjinfo->syn_righthand); + + /* + * But the list of operator OIDs and the list of expressions may be + * referenced somewhere else. Do not free those. + */ } /* -- 2.25.1