From 6e8968cbadeec651963ed9b310551685799bf364 Mon Sep 17 00:00:00 2001 From: Thomas Munro Date: Mon, 2 Mar 2026 04:44:33 +1300 Subject: [PATCH v2 16/19] Use stack buffer in partition pruning. --- src/backend/partitioning/partbounds.c | 60 +++++++++++++++++---------- src/backend/partitioning/partprune.c | 17 +++++--- 2 files changed, 49 insertions(+), 28 deletions(-) diff --git a/src/backend/partitioning/partbounds.c b/src/backend/partitioning/partbounds.c index 0ca312ac27d..fc0ae489aaa 100644 --- a/src/backend/partitioning/partbounds.c +++ b/src/backend/partitioning/partbounds.c @@ -39,6 +39,7 @@ #include "utils/partcache.h" #include "utils/ruleutils.h" #include "utils/snapmgr.h" +#include "utils/stack_buffer.h" #include "utils/syscache.h" /* @@ -354,13 +355,15 @@ create_hash_bounds(PartitionBoundSpec **boundspecs, int nparts, int greatest_modulus; Datum *boundDatums; + DECLARE_STACK_BUFFER(); + boundinfo = palloc0_object(PartitionBoundInfoData); boundinfo->strategy = key->strategy; /* No special hash partitions. */ boundinfo->null_index = -1; boundinfo->default_index = -1; - hbounds = palloc_array(PartitionHashBound, nparts); + hbounds = stack_buffer_alloc_array(PartitionHashBound, nparts); /* Convert from node to the internal representation */ for (i = 0; i < nparts; i++) @@ -422,7 +425,7 @@ create_hash_bounds(PartitionBoundSpec **boundspecs, int nparts, (*mapping)[hbounds[i].index] = i; } - pfree(hbounds); + stack_buffer_free(hbounds); return boundinfo; } @@ -471,6 +474,8 @@ create_list_bounds(PartitionBoundSpec **boundspecs, int nparts, int null_index = -1; Datum *boundDatums; + DECLARE_STACK_BUFFER(); + boundinfo = palloc0_object(PartitionBoundInfoData); boundinfo->strategy = key->strategy; /* Will be set correctly below. */ @@ -479,7 +484,7 @@ create_list_bounds(PartitionBoundSpec **boundspecs, int nparts, ndatums = get_non_null_list_datum_count(boundspecs, nparts); all_values = (PartitionListValue *) - palloc(ndatums * sizeof(PartitionListValue)); + stack_buffer_alloc_array(PartitionListValue, ndatums); /* Create a unified list of non-null values across all partitions. */ for (j = 0, i = 0; i < nparts; i++) @@ -566,7 +571,7 @@ create_list_bounds(PartitionBoundSpec **boundspecs, int nparts, boundinfo->indexes[i] = (*mapping)[orig_index]; } - pfree(all_values); + stack_buffer_free(all_values); /* * Set the canonical value for null_index, if any. @@ -688,6 +693,8 @@ create_range_bounds(PartitionBoundSpec **boundspecs, int nparts, Datum *boundDatums; PartitionRangeDatumKind *boundKinds; + DECLARE_STACK_BUFFER(); + boundinfo = palloc0_object(PartitionBoundInfoData); boundinfo->strategy = key->strategy; /* There is no special null-accepting range partition. */ @@ -695,7 +702,7 @@ create_range_bounds(PartitionBoundSpec **boundspecs, int nparts, /* Will be set correctly below. */ boundinfo->default_index = -1; - all_bounds = palloc0_array(PartitionRangeBound *, 2 * nparts); + all_bounds = stack_buffer_alloc0_array(PartitionRangeBound *, 2 * nparts); /* Create a unified list of range bounds across all the partitions. */ ndatums = 0; @@ -735,8 +742,7 @@ create_range_bounds(PartitionBoundSpec **boundspecs, int nparts, key); /* Save distinct bounds from all_bounds into rbounds. */ - rbounds = (PartitionRangeBound **) - palloc(ndatums * sizeof(PartitionRangeBound *)); + rbounds = stack_buffer_alloc_array(PartitionRangeBound *, ndatums); k = 0; prev = NULL; for (i = 0; i < ndatums; i++) @@ -785,7 +791,7 @@ create_range_bounds(PartitionBoundSpec **boundspecs, int nparts, prev = cur; } - pfree(all_bounds); + stack_buffer_free(all_bounds); /* Update ndatums to hold the count of distinct datums. */ ndatums = k; @@ -858,7 +864,7 @@ create_range_bounds(PartitionBoundSpec **boundspecs, int nparts, } } - pfree(rbounds); + stack_buffer_free(rbounds); /* Set the canonical value for default_index, if any. */ if (default_index != -1) @@ -2384,9 +2390,11 @@ fix_merged_indexes(PartitionMap *outer_map, PartitionMap *inner_map, int i; ListCell *lc; + DECLARE_STACK_BUFFER(); + Assert(nmerged > 0); - new_indexes = palloc_array(int, nmerged); + new_indexes = stack_buffer_alloc_array(int, nmerged); for (i = 0; i < nmerged; i++) new_indexes[i] = -1; @@ -2419,7 +2427,7 @@ fix_merged_indexes(PartitionMap *outer_map, PartitionMap *inner_map, lfirst_int(lc) = new_indexes[merged_index]; } - pfree(new_indexes); + stack_buffer_free(new_indexes); } /* @@ -2442,12 +2450,14 @@ generate_matching_part_pairs(RelOptInfo *outer_rel, RelOptInfo *inner_rel, int max_nparts; int i; + DECLARE_STACK_BUFFER(); + Assert(nmerged > 0); Assert(*outer_parts == NIL); Assert(*inner_parts == NIL); - outer_indexes = palloc_array(int, nmerged); - inner_indexes = palloc_array(int, nmerged); + outer_indexes = stack_buffer_alloc_array(int, nmerged); + inner_indexes = stack_buffer_alloc_array(int, nmerged); for (i = 0; i < nmerged; i++) outer_indexes[i] = inner_indexes[i] = -1; @@ -2500,8 +2510,8 @@ generate_matching_part_pairs(RelOptInfo *outer_rel, RelOptInfo *inner_rel, inner_rel->part_rels[inner_index] : NULL); } - pfree(outer_indexes); - pfree(inner_indexes); + stack_buffer_free(outer_indexes); + stack_buffer_free(inner_indexes); } /* @@ -5104,6 +5114,8 @@ calculate_partition_bound_for_merge(Relation parent, PartitionKey key = RelationGetPartitionKey(parent); PartitionBoundSpec *bound; + DECLARE_STACK_BUFFER(); + Assert(!spec->is_default); switch (key->strategy) @@ -5115,7 +5127,7 @@ calculate_partition_bound_for_merge(Relation parent, int nparts = list_length(partOids); List *bounds = NIL; - lower_bounds = palloc0_array(PartitionRangeBound *, nparts); + lower_bounds = stack_buffer_alloc0_array(PartitionRangeBound *, nparts); /* * Create an array of lower bounds and a list of @@ -5164,7 +5176,7 @@ calculate_partition_bound_for_merge(Relation parent, spec->upperdatums = ((PartitionBoundSpec *) list_nth(bounds, lower_bounds[nparts - 1]->index))->upperdatums; - pfree(lower_bounds); + stack_buffer_free(lower_bounds); list_free(bounds); break; } @@ -5741,6 +5753,8 @@ check_partitions_for_split(Relation parent, */ int nparts = 0; + DECLARE_STACK_BUFFER(); + key = RelationGetPartitionKey(parent); strategy = get_partition_strategy(key); @@ -5754,7 +5768,7 @@ check_partitions_for_split(Relation parent, * Make an array new_parts with new partitions except the DEFAULT * partition. */ - new_parts = palloc0_array(SinglePartitionSpec *, list_length(partlist)); + new_parts = stack_buffer_alloc0_array(SinglePartitionSpec *, list_length(partlist)); /* isSplitPartDefault flag: is split partition a DEFAULT partition? */ isSplitPartDefault = (defaultPartOid == splitPartOid); @@ -5784,7 +5798,7 @@ check_partitions_for_split(Relation parent, * all partitions in ascending order of their bounds (we compare the * lower bound only). */ - lower_bounds = palloc0_array(PartitionRangeBound *, nparts); + lower_bounds = stack_buffer_alloc0_array(PartitionRangeBound *, nparts); /* Create an array of lower bounds. */ for (i = 0; i < nparts; i++) @@ -5799,12 +5813,12 @@ check_partitions_for_split(Relation parent, /* Reorder the array of partitions. */ tmp_new_parts = new_parts; - new_parts = palloc0_array(SinglePartitionSpec *, nparts); + new_parts = stack_buffer_alloc0_array(SinglePartitionSpec *, nparts); for (i = 0; i < nparts; i++) new_parts[i] = tmp_new_parts[lower_bounds[i]->index]; - pfree(tmp_new_parts); - pfree(lower_bounds); + stack_buffer_free(tmp_new_parts); + stack_buffer_free(lower_bounds); } for (i = 0; i < nparts; i++) @@ -5871,5 +5885,5 @@ check_partitions_for_split(Relation parent, new_parts, nparts, pstate); } - pfree(new_parts); + stack_buffer_free(new_parts); } diff --git a/src/backend/partitioning/partprune.c b/src/backend/partitioning/partprune.c index 6d979a08fd3..8c4bf1d657e 100644 --- a/src/backend/partitioning/partprune.c +++ b/src/backend/partitioning/partprune.c @@ -54,6 +54,7 @@ #include "partitioning/partprune.h" #include "utils/array.h" #include "utils/lsyscache.h" +#include "utils/stack_buffer.h" /* @@ -233,6 +234,8 @@ make_partition_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel, ListCell *lc; int i; + DECLARE_STACK_BUFFER(); + /* * Scan the subpaths to see which ones are scans of partition child * relations, and identify their parent partitioned rels. (Note: we must @@ -246,7 +249,8 @@ make_partition_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel, * that zero can represent an un-filled array entry. */ allpartrelids = NIL; - relid_subplan_map = palloc0_array(int, root->simple_rel_array_size); + relid_subplan_map = stack_buffer_alloc0_array(int, + root->simple_rel_array_size); i = 1; foreach(lc, subpaths) @@ -327,7 +331,7 @@ make_partition_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel, } } - pfree(relid_subplan_map); + stack_buffer_free(relid_subplan_map); /* * If none of the partition hierarchies had any useful run-time pruning @@ -457,6 +461,8 @@ make_partitionedrel_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel, int rti; int i; + DECLARE_STACK_BUFFER(); + /* * Examine each partitioned rel, constructing a temporary array to map * from planner relids to index of the partitioned rel, and building a @@ -465,7 +471,8 @@ make_partitionedrel_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel, * In this phase we discover whether runtime pruning is needed at all; if * not, we can avoid doing further work. */ - relid_subpart_map = palloc0_array(int, root->simple_rel_array_size); + relid_subpart_map = stack_buffer_alloc0_array(int, + root->simple_rel_array_size); i = 1; rti = -1; @@ -624,7 +631,7 @@ make_partitionedrel_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel, if (!doruntimeprune) { /* No run-time pruning required. */ - pfree(relid_subpart_map); + stack_buffer_free(relid_subpart_map); return NIL; } @@ -719,7 +726,7 @@ make_partitionedrel_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel, pinfo->leafpart_rti_map = leafpart_rti_map; } - pfree(relid_subpart_map); + stack_buffer_free(relid_subpart_map); *matchedsubplans = subplansfound; -- 2.53.0