From 437770dd62f606610e1563f201bdf1748a890202 Mon Sep 17 00:00:00 2001 From: Manuel Reyes Bravo Date: Thu, 15 Oct 2026 23:50:00 -0300 Subject: [PATCH v6 2/2] Test that the confrelid lookups use the new index The four lookups by confrelid are covered functionally by the existing tests, but nothing fails if one of them goes back to a sequential scan of pg_constraint. Check in stats.sql that each of them adds an index scan of pg_constraint_confrelid_index. The check only asks for the counter to grow, so concurrent sessions cannot make it fail; reverting any one of the four call sites to a heap scan flips exactly its column. --- src/test/regress/expected/stats.out | 66 +++++++++++++++++++++++++++++ src/test/regress/sql/stats.sql | 37 ++++++++++++++++ 2 files changed, 103 insertions(+) diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index 8b15471248b..4522661e69f 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -2154,4 +2154,70 @@ SELECT fastpath_exceeded > :backend_fastpath_exceeded_before (1 row) DROP TABLE part_test; +-- Test that the lookups of foreign keys by referenced relation use +-- pg_constraint_confrelid_index. Each statement below must add an index +-- scan; other sessions can only add more, so this cannot fail spuriously. +CREATE TABLE confrelid_pk (id int PRIMARY KEY) PARTITION BY LIST (id); +CREATE TABLE confrelid_fk (pid int REFERENCES confrelid_pk); +CREATE TABLE confrelid_ul (a int); +CREATE FUNCTION confrelid_idx_scan() RETURNS bigint LANGUAGE sql AS + $$SELECT idx_scan FROM pg_stat_sys_indexes + WHERE indexrelname = 'pg_constraint_confrelid_index'$$; +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT confrelid_idx_scan() AS confrelid_scans \gset +-- CloneFkReferenced() +CREATE TABLE confrelid_pk1 PARTITION OF confrelid_pk FOR VALUES IN (1); +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT confrelid_idx_scan() > :confrelid_scans AS clone_fk_referenced, + confrelid_idx_scan() AS confrelid_scans \gset +-- GetParentedForeignKeyRefs() +ALTER TABLE confrelid_pk DETACH PARTITION confrelid_pk1; +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT confrelid_idx_scan() > :confrelid_scans AS get_parented_fk_refs, + confrelid_idx_scan() AS confrelid_scans \gset +-- heap_truncate_find_FKs() +TRUNCATE confrelid_pk1; +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT confrelid_idx_scan() > :confrelid_scans AS heap_truncate_find_fks, + confrelid_idx_scan() AS confrelid_scans \gset +-- ATPrepChangePersistence() +ALTER TABLE confrelid_ul SET UNLOGGED; +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT confrelid_idx_scan() > :confrelid_scans AS change_persistence \gset +SELECT :'clone_fk_referenced' AS clone_fk_referenced, + :'get_parented_fk_refs' AS get_parented_fk_refs, + :'heap_truncate_find_fks' AS heap_truncate_find_fks, + :'change_persistence' AS change_persistence; + clone_fk_referenced | get_parented_fk_refs | heap_truncate_find_fks | change_persistence +---------------------+----------------------+------------------------+-------------------- + t | t | t | t +(1 row) + +DROP TABLE confrelid_fk, confrelid_pk, confrelid_pk1, confrelid_ul; +DROP FUNCTION confrelid_idx_scan(); -- End of Stats Test diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 674637e172b..5953c5ae5bf 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -1070,4 +1070,41 @@ SELECT fastpath_exceeded > :backend_fastpath_exceeded_before DROP TABLE part_test; +-- Test that the lookups of foreign keys by referenced relation use +-- pg_constraint_confrelid_index. Each statement below must add an index +-- scan; other sessions can only add more, so this cannot fail spuriously. +CREATE TABLE confrelid_pk (id int PRIMARY KEY) PARTITION BY LIST (id); +CREATE TABLE confrelid_fk (pid int REFERENCES confrelid_pk); +CREATE TABLE confrelid_ul (a int); +CREATE FUNCTION confrelid_idx_scan() RETURNS bigint LANGUAGE sql AS + $$SELECT idx_scan FROM pg_stat_sys_indexes + WHERE indexrelname = 'pg_constraint_confrelid_index'$$; +SELECT pg_stat_force_next_flush(); +SELECT confrelid_idx_scan() AS confrelid_scans \gset +-- CloneFkReferenced() +CREATE TABLE confrelid_pk1 PARTITION OF confrelid_pk FOR VALUES IN (1); +SELECT pg_stat_force_next_flush(); +SELECT confrelid_idx_scan() > :confrelid_scans AS clone_fk_referenced, + confrelid_idx_scan() AS confrelid_scans \gset +-- GetParentedForeignKeyRefs() +ALTER TABLE confrelid_pk DETACH PARTITION confrelid_pk1; +SELECT pg_stat_force_next_flush(); +SELECT confrelid_idx_scan() > :confrelid_scans AS get_parented_fk_refs, + confrelid_idx_scan() AS confrelid_scans \gset +-- heap_truncate_find_FKs() +TRUNCATE confrelid_pk1; +SELECT pg_stat_force_next_flush(); +SELECT confrelid_idx_scan() > :confrelid_scans AS heap_truncate_find_fks, + confrelid_idx_scan() AS confrelid_scans \gset +-- ATPrepChangePersistence() +ALTER TABLE confrelid_ul SET UNLOGGED; +SELECT pg_stat_force_next_flush(); +SELECT confrelid_idx_scan() > :confrelid_scans AS change_persistence \gset +SELECT :'clone_fk_referenced' AS clone_fk_referenced, + :'get_parented_fk_refs' AS get_parented_fk_refs, + :'heap_truncate_find_fks' AS heap_truncate_find_fks, + :'change_persistence' AS change_persistence; +DROP TABLE confrelid_fk, confrelid_pk, confrelid_pk1, confrelid_ul; +DROP FUNCTION confrelid_idx_scan(); + -- End of Stats Test