From 9a8d0bd1806694651b02cc994810bc973dcfc026 Mon Sep 17 00:00:00 2001 From: Thomas Munro Date: Mon, 2 Mar 2026 02:35:03 +1300 Subject: [PATCH v2 18/19] Use stack buffer for tlist indexes in planner. --- src/backend/optimizer/plan/setrefs.c | 86 +++++++++++++++++++--------- 1 file changed, 58 insertions(+), 28 deletions(-) diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c index 1b5b9b5ed9c..bc048c397a2 100644 --- a/src/backend/optimizer/plan/setrefs.c +++ b/src/backend/optimizer/plan/setrefs.c @@ -28,6 +28,7 @@ #include "parser/parse_relation.h" #include "rewrite/rewriteManip.h" #include "tcop/utility.h" +#include "utils/stack_buffer.h" #include "utils/syscache.h" @@ -166,7 +167,15 @@ static void set_upper_references(PlannerInfo *root, Plan *plan, int rtoffset); static void set_param_references(PlannerInfo *root, Plan *plan); static Node *convert_combining_aggrefs(Node *node, void *context); static void set_dummy_tlist_references(Plan *plan, int rtoffset); -static indexed_tlist *build_tlist_index(List *tlist); +static size_t tlist_index_size(List *tlist); +static indexed_tlist *fill_tlist_index(indexed_tlist *itlist, List *tlist); +#define build_tlist_index(tlist) \ + fill_tlist_index(stack_buffer_alloc(tlist_index_size(tlist)), (tlist)) +#define build_tlist_index_other_vars(tlist, ignore_rel) \ + fill_tlist_index_other_vars(stack_buffer_alloc(tlist_index_size(tlist)), \ + (tlist), (ignore_rel)) +#define free_tlist_index(itlist) \ + stack_buffer_free(itlist) static Var *search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist, int newvarno, @@ -643,6 +652,8 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset) { ListCell *l; + DECLARE_STACK_BUFFER(); + if (plan == NULL) return NULL; @@ -1182,7 +1193,7 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset) linitial_int(splan->resultRelations), rtoffset, NRM_EQUAL, NUM_EXEC_QUAL(plan)); - pfree(itlist); + free_tlist_index(itlist); splan->exclRelTlist = fix_scan_list(root, splan->exclRelTlist, rtoffset, 1); @@ -1383,6 +1394,8 @@ set_indexonlyscan_references(PlannerInfo *root, List *stripped_indextlist; ListCell *lc; + DECLARE_STACK_BUFFER(); + /* * Vars in the plan node's targetlist, qual, and recheckqual must only * reference columns that the index AM can actually return. To ensure @@ -1436,7 +1449,7 @@ set_indexonlyscan_references(PlannerInfo *root, plan->indextlist = fix_scan_list(root, plan->indextlist, rtoffset, NUM_EXEC_TLIST((Plan *) plan)); - pfree(index_itlist); + free_tlist_index(index_itlist); return (Plan *) plan; } @@ -1643,6 +1656,8 @@ set_foreignscan_references(PlannerInfo *root, ForeignScan *fscan, int rtoffset) { + DECLARE_STACK_BUFFER(); + /* Adjust scanrelid if it's valid */ if (fscan->scan.scanrelid > 0) fscan->scan.scanrelid += rtoffset; @@ -1687,7 +1702,7 @@ set_foreignscan_references(PlannerInfo *root, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) fscan)); - pfree(itlist); + free_tlist_index(itlist); /* fdw_scan_tlist itself just needs fix_scan_list() adjustments */ fscan->fdw_scan_tlist = fix_scan_list(root, fscan->fdw_scan_tlist, @@ -1732,6 +1747,8 @@ set_customscan_references(PlannerInfo *root, { ListCell *lc; + DECLARE_STACK_BUFFER(); + /* Adjust scanrelid if it's valid */ if (cscan->scan.scanrelid > 0) cscan->scan.scanrelid += rtoffset; @@ -1765,7 +1782,7 @@ set_customscan_references(PlannerInfo *root, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) cscan)); - pfree(itlist); + free_tlist_index(itlist); /* custom_scan_tlist itself just needs fix_scan_list() adjustments */ cscan->custom_scan_tlist = fix_scan_list(root, cscan->custom_scan_tlist, @@ -2028,6 +2045,8 @@ set_hash_references(PlannerInfo *root, Plan *plan, int rtoffset) Plan *outer_plan = plan->lefttree; indexed_tlist *outer_itlist; + DECLARE_STACK_BUFFER(); + /* * Hash's hashkeys are used when feeding tuples into the hashtable, * therefore have them reference Hash's outer plan (which itself is the @@ -2042,6 +2061,7 @@ set_hash_references(PlannerInfo *root, Plan *plan, int rtoffset) rtoffset, NRM_EQUAL, NUM_EXEC_QUAL(plan)); + free_tlist_index(outer_itlist); /* Hash doesn't project */ set_dummy_tlist_references(plan, rtoffset); @@ -2408,6 +2428,8 @@ set_join_references(PlannerInfo *root, Join *join, int rtoffset) indexed_tlist *outer_itlist; indexed_tlist *inner_itlist; + DECLARE_STACK_BUFFER(); + outer_itlist = build_tlist_index(outer_plan->targetlist); inner_itlist = build_tlist_index(inner_plan->targetlist); @@ -2527,8 +2549,8 @@ set_join_references(PlannerInfo *root, Join *join, int rtoffset) (join->jointype == JOIN_INNER ? NRM_EQUAL : NRM_SUPERSET), NUM_EXEC_QUAL((Plan *) join)); - pfree(outer_itlist); - pfree(inner_itlist); + free_tlist_index(outer_itlist); + free_tlist_index(inner_itlist); } /* @@ -2557,6 +2579,8 @@ set_upper_references(PlannerInfo *root, Plan *plan, int rtoffset) List *output_targetlist; ListCell *l; + DECLARE_STACK_BUFFER(); + subplan_itlist = build_tlist_index(subplan->targetlist); /* @@ -2627,7 +2651,7 @@ set_upper_references(PlannerInfo *root, Plan *plan, int rtoffset) NRM_EQUAL, NUM_EXEC_QUAL(plan)); - pfree(subplan_itlist); + free_tlist_index(subplan_itlist); } /* @@ -2815,7 +2839,19 @@ set_dummy_tlist_references(Plan *plan, int rtoffset) /* - * build_tlist_index --- build an index data structure for a child tlist + * tlist_index_size --- compute memory required to an indexed_tlist. + */ +static size_t +tlist_index_size(List *tlist) +{ + /* Require data structure with enough slots for all tlist entries */ + return offsetof(indexed_tlist, vars) + + list_length(tlist) * sizeof(tlist_vinfo); +} + + +/* + * fill_tlist_index --- build an index data structure for a child tlist * * In most cases, subplan tlists will be "flat" tlists with only Vars, * so we try to optimize that case by extracting information about Vars @@ -2825,20 +2861,16 @@ set_dummy_tlist_references(Plan *plan, int rtoffset) * * The result of this function is an indexed_tlist struct to pass to * search_indexed_tlist_for_var() and siblings. - * When done, the indexed_tlist may be freed with a single pfree(). + * + * The macro build_tlist_index() can be used to allocate memory in a stack + * buffer. When done, the indexed_tlist may be freed with free_tlist_index(). */ static indexed_tlist * -build_tlist_index(List *tlist) +fill_tlist_index(indexed_tlist *itlist, List *tlist) { - indexed_tlist *itlist; tlist_vinfo *vinfo; ListCell *l; - /* Create data structure with enough slots for all tlist entries */ - itlist = (indexed_tlist *) - palloc(offsetof(indexed_tlist, vars) + - list_length(tlist) * sizeof(tlist_vinfo)); - itlist->tlist = tlist; itlist->has_ph_vars = false; itlist->has_non_vars = false; @@ -2871,25 +2903,19 @@ build_tlist_index(List *tlist) } /* - * build_tlist_index_other_vars --- build a restricted tlist index + * fill_tlist_index_other_vars --- build a restricted tlist index * - * This is like build_tlist_index, but we only index tlist entries that + * This is like fill_tlist_index, but we only index tlist entries that * are Vars belonging to some rel other than the one specified. We will set * has_ph_vars (allowing PlaceHolderVars to be matched), but not has_non_vars * (so nothing other than Vars and PlaceHolderVars can be matched). */ static indexed_tlist * -build_tlist_index_other_vars(List *tlist, int ignore_rel) +fill_tlist_index_other_vars(indexed_tlist *itlist, List *tlist, int ignore_rel) { - indexed_tlist *itlist; tlist_vinfo *vinfo; ListCell *l; - /* Create data structure with enough slots for all tlist entries */ - itlist = (indexed_tlist *) - palloc(offsetof(indexed_tlist, vars) + - list_length(tlist) * sizeof(tlist_vinfo)); - itlist->tlist = tlist; itlist->has_ph_vars = false; itlist->has_non_vars = false; @@ -3476,6 +3502,8 @@ set_returning_clause_references(PlannerInfo *root, { indexed_tlist *itlist; + DECLARE_STACK_BUFFER(); + /* * We can perform the desired Var fixup by abusing the fix_join_expr * machinery that formerly handled inner indexscan fixup. We search the @@ -3501,7 +3529,7 @@ set_returning_clause_references(PlannerInfo *root, NRM_EQUAL, NUM_EXEC_TLIST(topplan)); - pfree(itlist); + free_tlist_index(itlist); return rlist; } @@ -3570,11 +3598,13 @@ set_windowagg_runcondition_references(PlannerInfo *root, List *newlist; indexed_tlist *itlist; + DECLARE_STACK_BUFFER(); + itlist = build_tlist_index(plan->targetlist); newlist = fix_windowagg_condition_expr(root, runcondition, itlist); - pfree(itlist); + free_tlist_index(itlist); return newlist; } -- 2.53.0