From 72e3abd082c3ae6db4081137a7431fdd05e55d73 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Sun, 25 Jan 2026 19:01:23 +0900 Subject: [PATCH] pg_stat_statements: Fix test instability with cache-clobbering builds Builds with CLOBBER_CACHE_ALWAYS enabled are failing the new test introduced in 1572ea96e657, checking the nesting level calculation in the planner hook. The inner query of the function called twice is registered as normalized, as such builds would register a PGSS entry in the post-parse-analyse hook due to the cached plans requiring revalidation. A trick based on debug_discard_caches cannot work as far as I can, a normalized query still being registered. This commit takes a different approach with the addition of a DISCARD PLANS before the first function call. This forces the use of a normalized query in the PGSS entry for the inner query of the function with and without CLOBBER_CACHE_ALWAYS, which should be enough to stabilize the test. Note that the test is still checking what it should: when removing the nesting level calculation in the planner hook of PGSS, one still gets a failure for the PGSS entry of the inner query in the function, with "toplevel" being flipped to true instead of false (it should be false, as a non-top-level entry). Per buildfarm members avocet and trilobite, at least. Reported-by: Alexander Lakhin Discussion: https://postgr.es/m/82dd02bb-4e0f-40ad-a60b-baa1763ff0bd@gmail.com --- contrib/pg_stat_statements/expected/level_tracking.out | 9 ++++++++- contrib/pg_stat_statements/sql/level_tracking.sql | 8 +++++++- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/contrib/pg_stat_statements/expected/level_tracking.out b/contrib/pg_stat_statements/expected/level_tracking.out index 35e889fabd2..a15d897e59b 100644 --- a/contrib/pg_stat_statements/expected/level_tracking.out +++ b/contrib/pg_stat_statements/expected/level_tracking.out @@ -1543,6 +1543,13 @@ SELECT pg_stat_statements_reset() IS NOT NULL AS t; -- planner - all-level tracking. SET pg_stat_statements.track_planning = TRUE; +-- Release all cached plans before the first function call. This matters +-- when debug_discard_caches is enabled, which would store a normalized +-- version of the inner query of the function. Forcing a plan rebuild +-- ensures that a normalized version is always stored with the stats entry, +-- while checking that the nesting level is computed correctly in the +-- planner hook. +DISCARD PLANS; SELECT PLUS_THREE(8); plus_three ------------ @@ -1560,7 +1567,7 @@ SELECT toplevel, calls, rows, plans, query FROM pg_stat_statements toplevel | calls | rows | plans | query ----------+-------+------+-------+-------------------------------------------------------------------- t | 2 | 2 | 2 | SELECT PLUS_THREE($1) - f | 2 | 2 | 2 | SELECT i + 3 LIMIT 1 + f | 2 | 2 | 2 | SELECT i + $2 LIMIT $3 t | 1 | 1 | 0 | SELECT pg_stat_statements_reset() IS NOT NULL AS t t | 0 | 0 | 1 | SELECT toplevel, calls, rows, plans, query FROM pg_stat_statements+ | | | | ORDER BY query COLLATE "C" diff --git a/contrib/pg_stat_statements/sql/level_tracking.sql b/contrib/pg_stat_statements/sql/level_tracking.sql index 8dd3fc2df08..003efb8184b 100644 --- a/contrib/pg_stat_statements/sql/level_tracking.sql +++ b/contrib/pg_stat_statements/sql/level_tracking.sql @@ -435,7 +435,13 @@ SELECT pg_stat_statements_reset() IS NOT NULL AS t; -- planner - all-level tracking. SET pg_stat_statements.track_planning = TRUE; - +-- Release all cached plans before the first function call. This matters +-- when debug_discard_caches is enabled, which would store a normalized +-- version of the inner query of the function. Forcing a plan rebuild +-- ensures that a normalized version is always stored with the stats entry, +-- while checking that the nesting level is computed correctly in the +-- planner hook. +DISCARD PLANS; SELECT PLUS_THREE(8); SELECT PLUS_THREE(10);