postgres.git / summary / log / commit / refs

commit    ddee5d03077c05925e83533e50ebe805c934d2cf
Author:   Robert Haas <rhaas@postgresql.org>
Date:     Wed Sep 09 21:48:54 2026 +0000

    pg_plan_advice: Add CHECK_FOR_INTERRUPTS() and check_stack_depth()
    
    Without CHECK_FOR_INTERRUPTS(), backends might not respond to query
    cancellations in a timely fashion, especially for JOIN_ORDER()
    specifications, where matching against each join can take O(n^2) time
    in the length of the join order list in degenerate cases.
    
    Recursive functions should check_stack_depth().
    
    Reported-by: Noah Misch <noah@leadboat.com>
    Discussion: https://postgr.es/m/CA+TgmoYmXy-jiP5qDhqNEiYFEBzQsArO6O2d9E8szNZqi1bePQ@mail.gmail.com
    Backpatch-through: 19


 contrib/pg_plan_advice/pgpa_ast.c     | 14 ++++++++++++++
 contrib/pg_plan_advice/pgpa_planner.c |  7 +++++++
 contrib/pg_plan_advice/pgpa_trove.c   |  3 +++
 3 files changed, 24 insertions(+)

diff --git a/contrib/pg_plan_advice/pgpa_ast.c b/contrib/pg_plan_advice/pgpa_ast.c
index 01db8d24cd0..82254a9589c 100644
--- a/contrib/pg_plan_advice/pgpa_ast.c
+++ b/contrib/pg_plan_advice/pgpa_ast.c
@@ -15,6 +15,7 @@
 #include "pgpa_ast.h"
 
 #include "funcapi.h"
+#include "miscadmin.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 
@@ -169,6 +170,8 @@ pgpa_parse_advice_tag(const char *tag, bool *fail)
 void
 pgpa_format_advice_target(StringInfo str, pgpa_advice_target *target)
 {
+	check_stack_depth();
+
 	if (target->ttype != PGPA_TARGET_IDENTIFIER)
 	{
 		bool		first = true;
@@ -234,6 +237,8 @@ pgpa_index_targets_equal(pgpa_index_target *i1, pgpa_index_target *i2)
 bool
 pgpa_identifier_matches_target(pgpa_identifier *rid, pgpa_advice_target *target)
 {
+	check_stack_depth();
+
 	/* For non-identifiers, check all descendants. */
 	if (target->ttype != PGPA_TARGET_IDENTIFIER)
 	{
@@ -288,6 +293,13 @@ pgpa_identifiers_match_target(int nrids, pgpa_identifier *rids,
 	bool		all_targets_used;
 	bool	   *rids_used = palloc0_array(bool, nrids);
 
+	/*
+	 * This function is called from within various loops within pgpa_planner.c;
+	 * to avoid needing a separate CHECK_FOR_INTERRUPTS() in each one, we check
+	 * here instead.
+	 */
+	CHECK_FOR_INTERRUPTS();
+
 	all_targets_used =
 		pgpa_identifiers_cover_target(nrids, rids, target, rids_used);
 
@@ -330,6 +342,8 @@ pgpa_identifiers_cover_target(int nrids, pgpa_identifier *rids,
 {
 	bool		result = false;
 
+	check_stack_depth();
+
 	if (target->ttype != PGPA_TARGET_IDENTIFIER)
 	{
 		result = true;
diff --git a/contrib/pg_plan_advice/pgpa_planner.c b/contrib/pg_plan_advice/pgpa_planner.c
index b3329b793aa..c57df4aa7f0 100644
--- a/contrib/pg_plan_advice/pgpa_planner.c
+++ b/contrib/pg_plan_advice/pgpa_planner.c
@@ -25,6 +25,7 @@
 
 #include "commands/defrem.h"
 #include "common/hashfn_unstable.h"
+#include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "optimizer/extendplan.h"
 #include "optimizer/pathnode.h"
@@ -1649,6 +1650,8 @@ pgpa_planner_apply_scan_advice(RelOptInfo *rel,
 		pgpa_trove_entry *my_entry = &scan_entries[i];
 		uint64		my_scan_type = all_scan_mask;
 
+		CHECK_FOR_INTERRUPTS();
+
 		/* Translate our advice tags to a scan strategy advice value. */
 		if (my_entry->tag == PGPA_TAG_DO_NOT_SCAN)
 			my_scan_type = 0;
@@ -1711,6 +1714,8 @@ pgpa_planner_apply_scan_advice(RelOptInfo *rel,
 		uint64		my_gather_mask = 0;
 		bool		just_one_rel;
 
+		CHECK_FOR_INTERRUPTS();
+
 		just_one_rel = my_entry->target->ttype == PGPA_TARGET_IDENTIFIER
 			|| list_length(my_entry->target->children) == 1;
 
@@ -1882,6 +1887,8 @@ pgpa_planner_append_feedback(List *list, pgpa_trove *trove,
 		pgpa_trove_entry *entry = &entries[i];
 		DefElem    *item;
 
+		CHECK_FOR_INTERRUPTS();
+
 		/*
 		 * If this entry was fully matched, check whether generating advice
 		 * from this plan would produce such an entry. If not, label the entry
diff --git a/contrib/pg_plan_advice/pgpa_trove.c b/contrib/pg_plan_advice/pgpa_trove.c
index ca69f3bd3df..e5840051386 100644
--- a/contrib/pg_plan_advice/pgpa_trove.c
+++ b/contrib/pg_plan_advice/pgpa_trove.c
@@ -27,6 +27,7 @@
 #include "pgpa_trove.h"
 
 #include "common/hashfn_unstable.h"
+#include "miscadmin.h"
 
 /*
  * An advice trove is organized into a series of "slices", each of which
@@ -402,6 +403,8 @@ pgpa_trove_add_to_hash(pgpa_trove_entry_hash *hash, pgpa_advice_target *target,
 	pgpa_trove_entry_element *element;
 	bool		found;
 
+	check_stack_depth();
+
 	/* For non-identifiers, add entries for all descendants. */
 	if (target->ttype != PGPA_TARGET_IDENTIFIER)
 	{


[parent: 50ba390a4f81]