Michael Paquier 3357471cf9 pg_stat_statements: Add counters for generic and custom plans
This patch adds two new counters to pg_stat_statements:
- generic_plan_calls
- custom_plan_calls

These counters track how many times a prepared statement was executed
using a generic or custom plan, respectively, providing a global
equivalent at query level, for top and non-top levels, of
pg_prepared_statements whose data is restricted to a single session.

This commit builds upon e125e360020a.  The module is bumped to version
1.13.  PGSS_FILE_HEADER is bumped as well, something that the latest
patches touching the on-disk format of the PGSS file did not actually
bother with since 2022..

Author: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com>
Reviewed-by: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Nikolay Samokhvalov <nik@postgres.ai>
Discussion: https://postgr.es/m/CAA5RZ0uFw8Y9GCFvafhC=OA8NnMqVZyzXPfv_EePOt+iv1T-qQ@mail.gmail.com
2025-07-31 11:37:37 +09:00

95 lines
2.8 KiB
PL/PgSQL

--
-- Tests with plan cache
--
-- Setup
CREATE OR REPLACE FUNCTION select_one_func(int) RETURNS VOID AS $$
DECLARE
ret INT;
BEGIN
SELECT $1 INTO ret;
END;
$$ LANGUAGE plpgsql;
CREATE OR REPLACE PROCEDURE select_one_proc(int) AS $$
DECLARE
ret INT;
BEGIN
SELECT $1 INTO ret;
END;
$$ LANGUAGE plpgsql;
-- Prepared statements
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
PREPARE p1 AS SELECT $1 AS a;
SET plan_cache_mode TO force_generic_plan;
EXECUTE p1(1);
SET plan_cache_mode TO force_custom_plan;
EXECUTE p1(1);
SELECT calls, generic_plan_calls, custom_plan_calls, query FROM pg_stat_statements
ORDER BY query COLLATE "C";
DEALLOCATE p1;
-- Extended query protocol
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
SELECT $1 AS a \parse p1
SET plan_cache_mode TO force_generic_plan;
\bind_named p1 1
;
SET plan_cache_mode TO force_custom_plan;
\bind_named p1 1
;
SELECT calls, generic_plan_calls, custom_plan_calls, query FROM pg_stat_statements
ORDER BY query COLLATE "C";
\close_prepared p1
-- EXPLAIN [ANALYZE] EXECUTE
SET pg_stat_statements.track = 'all';
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
PREPARE p1 AS SELECT $1;
SET plan_cache_mode TO force_generic_plan;
EXPLAIN (COSTS OFF) EXECUTE p1(1);
EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF, BUFFERS OFF) EXECUTE p1(1);
SET plan_cache_mode TO force_custom_plan;
EXPLAIN (COSTS OFF) EXECUTE p1(1);
EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF, BUFFERS OFF) EXECUTE p1(1);
SELECT calls, generic_plan_calls, custom_plan_calls, toplevel, query FROM pg_stat_statements
ORDER BY query COLLATE "C";
RESET pg_stat_statements.track;
DEALLOCATE p1;
-- Functions/procedures
SET pg_stat_statements.track = 'all';
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
SET plan_cache_mode TO force_generic_plan;
SELECT select_one_func(1);
CALL select_one_proc(1);
SET plan_cache_mode TO force_custom_plan;
SELECT select_one_func(1);
CALL select_one_proc(1);
SELECT calls, generic_plan_calls, custom_plan_calls, toplevel, query FROM pg_stat_statements
ORDER BY query COLLATE "C";
--
-- EXPLAIN [ANALYZE] EXECUTE + functions/procedures
--
SET pg_stat_statements.track = 'all';
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
SET plan_cache_mode TO force_generic_plan;
EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF, BUFFERS OFF) SELECT select_one_func(1);
EXPLAIN (COSTS OFF) SELECT select_one_func(1);
CALL select_one_proc(1);
SET plan_cache_mode TO force_custom_plan;
EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF, BUFFERS OFF) SELECT select_one_func(1);
EXPLAIN (COSTS OFF) SELECT select_one_func(1);
CALL select_one_proc(1);
SELECT calls, generic_plan_calls, custom_plan_calls, toplevel, query FROM pg_stat_statements
ORDER BY query COLLATE "C", toplevel;
RESET pg_stat_statements.track;
--
-- Cleanup
--
DROP FUNCTION select_one_func(int);
DROP PROCEDURE select_one_proc(int);