diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index 8baf36ba4b7..8011c3c4bc8 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -4344,6 +4344,7 @@ create_nestloop_plan(PlannerInfo *root, NestLoop *join_plan; Plan *outer_plan; Plan *inner_plan; + Relids outerrelids; List *tlist = build_path_tlist(root, &best_path->jpath.path); List *joinrestrictclauses = best_path->jpath.joinrestrictinfo; List *joinclauses; @@ -4374,8 +4375,8 @@ create_nestloop_plan(PlannerInfo *root, outer_plan = create_plan_recurse(root, best_path->jpath.outerjoinpath, 0); /* For a nestloop, include outer relids in curOuterRels for inner side */ - root->curOuterRels = bms_union(root->curOuterRels, - best_path->jpath.outerjoinpath->parent->relids); + outerrelids = best_path->jpath.outerjoinpath->parent->relids; + root->curOuterRels = bms_union(root->curOuterRels, outerrelids); inner_plan = create_plan_recurse(root, best_path->jpath.innerjoinpath, 0); @@ -4415,7 +4416,8 @@ create_nestloop_plan(PlannerInfo *root, * node, and remove them from root->curOuterParams. */ nestParams = identify_current_nestloop_params(root, - best_path->jpath.outerjoinpath); + outerrelids, + PATH_REQ_OUTER((Path *) best_path)); /* * While nestloop parameters that are Vars had better be available from @@ -4423,32 +4425,77 @@ create_nestloop_plan(PlannerInfo *root, * that are PHVs won't be. In such cases we must add them to the * outer_plan's tlist, since the executor's NestLoopParam machinery * requires the params to be simple outer-Var references to that tlist. + * (This is cheating a little bit, because the outer path's required-outer + * relids might not be enough to allow evaluating such a PHV. But in + * practice, if we could have evaluated the PHV at the nestloop node, we + * can do so in the outer plan too.) */ outer_tlist = outer_plan->targetlist; outer_parallel_safe = outer_plan->parallel_safe; foreach(lc, nestParams) { NestLoopParam *nlp = (NestLoopParam *) lfirst(lc); + PlaceHolderVar *phv; TargetEntry *tle; if (IsA(nlp->paramval, Var)) continue; /* nothing to do for simple Vars */ - if (tlist_member((Expr *) nlp->paramval, outer_tlist)) + /* Otherwise it must be a PHV */ + phv = castNode(PlaceHolderVar, nlp->paramval); + + if (tlist_member((Expr *) phv, outer_tlist)) continue; /* already available */ + /* + * Deal with an even edgier edge case: if the PHV was pulled up out of + * a subquery and it contains a subquery that was originally pushed + * down from this query level, then that will still be represented as + * a SubLink, because SS_process_sublinks won't recurse into outer + * PHVs, so it didn't get transformed during expression preprocessing + * in the subquery. We need a version of the PHV that has a SubPlan, + * which we can get from the current query level's placeholder_list. + * This is quite grotty of course, but dealing with it earlier in the + * handling of subplan params would be just as grotty, and it might + * end up being a waste of cycles if we don't decide to treat the PHV + * as a NestLoopParam. (Perhaps that whole mechanism should be + * redesigned someday, but today is not that day.) + * + * It's not important to change the NestLoopParam tree, because the + * two PHVs will still be considered equal() and thus setrefs.c will + * still be able to replace the NestLoopParam's PHV with an outer-plan + * reference Var. + * + * In either case, make sure we have a copy of the PHV to put into + * outer_tlist, just for safety. + */ + if (root->parse->hasSubLinks) + { + PlaceHolderInfo *phinfo = find_placeholder_info(root, phv); + PlaceHolderVar *newphv = copyObject(phinfo->ph_var); + + /* + * The ph_var will have empty nullingrels, but we need the right + * nullingrels in the PHV we push into outer_tlist. Other fields + * should match already. + */ + newphv->phnullingrels = phv->phnullingrels; + phv = newphv; + } + else + phv = copyObject(phv); + /* Make a shallow copy of outer_tlist, if we didn't already */ if (outer_tlist == outer_plan->targetlist) outer_tlist = list_copy(outer_tlist); /* ... and add the needed expression */ - tle = makeTargetEntry((Expr *) copyObject(nlp->paramval), + tle = makeTargetEntry((Expr *) phv, list_length(outer_tlist) + 1, NULL, true); outer_tlist = lappend(outer_tlist, tle); /* ... and track whether tlist is (still) parallel-safe */ if (outer_parallel_safe) - outer_parallel_safe = is_parallel_safe(root, - (Node *) nlp->paramval); + outer_parallel_safe = is_parallel_safe(root, (Node *) phv); } if (outer_tlist != outer_plan->targetlist) outer_plan = change_plan_targetlist(outer_plan, outer_tlist, diff --git a/src/backend/optimizer/util/paramassign.c b/src/backend/optimizer/util/paramassign.c index 9836abf9479..5403ae89eab 100644 --- a/src/backend/optimizer/util/paramassign.c +++ b/src/backend/optimizer/util/paramassign.c @@ -599,9 +599,10 @@ process_subquery_nestloop_params(PlannerInfo *root, List *subplan_params) } /* - * Identify any NestLoopParams that should be supplied by a NestLoop plan - * node with the specified lefthand input path. Remove them from the active - * root->curOuterParams list and return them as the result list. + * Identify any NestLoopParams that should be supplied by a NestLoop + * plan node with the specified lefthand rels and required-outer rels. + * Remove them from the active root->curOuterParams list and return + * them as the result list. * * XXX Here we also hack up the returned Vars and PHVs so that they do not * contain nullingrel sets exceeding what is available from the outer side. @@ -626,11 +627,11 @@ process_subquery_nestloop_params(PlannerInfo *root, List *subplan_params) * subquery, which'd be unduly expensive. */ List * -identify_current_nestloop_params(PlannerInfo *root, Path *leftpath) +identify_current_nestloop_params(PlannerInfo *root, + Relids leftrelids, + Relids outerrelids) { List *result; - Relids leftrelids = leftpath->parent->relids; - Relids outerrelids = PATH_REQ_OUTER(leftpath); Relids allleftrelids; ListCell *cell; diff --git a/src/include/optimizer/paramassign.h b/src/include/optimizer/paramassign.h index d30d20de299..bbf7214289b 100644 --- a/src/include/optimizer/paramassign.h +++ b/src/include/optimizer/paramassign.h @@ -30,7 +30,8 @@ extern Param *replace_nestloop_param_placeholdervar(PlannerInfo *root, extern void process_subquery_nestloop_params(PlannerInfo *root, List *subplan_params); extern List *identify_current_nestloop_params(PlannerInfo *root, - Path *leftpath); + Relids leftrelids, + Relids outerrelids); extern Param *generate_new_exec_param(PlannerInfo *root, Oid paramtype, int32 paramtypmod, Oid paramcollation); extern int assign_special_exec_param(PlannerInfo *root); diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out index c292f04fdba..6266820b69a 100644 --- a/src/test/regress/expected/join.out +++ b/src/test/regress/expected/join.out @@ -4119,6 +4119,91 @@ select * from int8_tbl t1 (16 rows) rollback; +-- PHVs containing SubLinks are quite tricky to get right +explain (verbose, costs off) +select * +from int8_tbl i8 + inner join + (select (select true) as x + from int4_tbl i4, lateral (select i4.f1 as y limit 1) ss1 + where i4.f1 = 0) ss2 on true + right join (select false as z) ss3 on true, + lateral (select i8.q2 as q2l where x limit 1) ss4 +where i8.q2 = 123; + QUERY PLAN +---------------------------------------------------------------- + Nested Loop + Output: i8.q1, i8.q2, (InitPlan 1).col1, false, (i8.q2) + InitPlan 1 + -> Result + Output: true + InitPlan 2 + -> Result + Output: true + -> Seq Scan on public.int4_tbl i4 + Output: i4.f1 + Filter: (i4.f1 = 0) + -> Nested Loop + Output: i8.q1, i8.q2, (i8.q2) + -> Subquery Scan on ss1 + Output: ss1.y, (InitPlan 1).col1 + -> Limit + Output: NULL::integer + -> Result + Output: NULL::integer + -> Nested Loop + Output: i8.q1, i8.q2, (i8.q2) + -> Seq Scan on public.int8_tbl i8 + Output: i8.q1, i8.q2 + Filter: (i8.q2 = 123) + -> Limit + Output: (i8.q2) + -> Result + Output: i8.q2 + One-Time Filter: ((InitPlan 1).col1) +(29 rows) + +explain (verbose, costs off) +select * +from int8_tbl i8 + inner join + (select (select true) as x + from int4_tbl i4, lateral (select 1 as y limit 1) ss1 + where i4.f1 = 0) ss2 on true + right join (select false as z) ss3 on true, + lateral (select i8.q2 as q2l where x limit 1) ss4 +where i8.q2 = 123; + QUERY PLAN +---------------------------------------------------------------- + Nested Loop + Output: i8.q1, i8.q2, (InitPlan 1).col1, false, (i8.q2) + InitPlan 1 + -> Result + Output: true + InitPlan 2 + -> Result + Output: true + -> Limit + Output: NULL::integer + -> Result + Output: NULL::integer + -> Nested Loop + Output: i8.q1, i8.q2, (i8.q2) + -> Seq Scan on public.int4_tbl i4 + Output: i4.f1, (InitPlan 1).col1 + Filter: (i4.f1 = 0) + -> Nested Loop + Output: i8.q1, i8.q2, (i8.q2) + -> Seq Scan on public.int8_tbl i8 + Output: i8.q1, i8.q2 + Filter: (i8.q2 = 123) + -> Limit + Output: (i8.q2) + -> Result + Output: i8.q2 + One-Time Filter: ((InitPlan 1).col1) +(27 rows) + -- Test proper handling of appendrel PHVs during useless-RTE removal explain (costs off) select * from diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql index 88d2204e447..6b7a26cf295 100644 --- a/src/test/regress/sql/join.sql +++ b/src/test/regress/sql/join.sql @@ -1361,6 +1361,29 @@ select * from int8_tbl t1 on true; rollback; +-- PHVs containing SubLinks are quite tricky to get right +explain (verbose, costs off) +select * +from int8_tbl i8 + inner join + (select (select true) as x + from int4_tbl i4, lateral (select i4.f1 as y limit 1) ss1 + where i4.f1 = 0) ss2 on true + right join (select false as z) ss3 on true, + lateral (select i8.q2 as q2l where x limit 1) ss4 +where i8.q2 = 123; + +explain (verbose, costs off) +select * +from int8_tbl i8 + inner join + (select (select true) as x + from int4_tbl i4, lateral (select 1 as y limit 1) ss1 + where i4.f1 = 0) ss2 on true + right join (select false as z) ss3 on true, + lateral (select i8.q2 as q2l where x limit 1) ss4 +where i8.q2 = 123; + -- Test proper handling of appendrel PHVs during useless-RTE removal explain (costs off) select * from