-- sift.col_verify's heap check must not use the index's cached state across tuples: a session that updates the index's statistics (VACUUM, ANALYZE)
-- sends an invalidation that reloads the index's relcache entry and frees that state. sift.test_col_verify_inval does it at every tuple, and
-- first overwrites the cached state, so a check that kept it reads garbage.
CREATE EXTENSION pg_sift_test CASCADE;
NOTICE:  installing required extension "pg_sift"
CREATE TABLE cv (id int PRIMARY KEY, g int, v float8, t text);
INSERT INTO cv SELECT i, i % 7, i / 3.0, 'row ' || i FROM generate_series(1, 2000) i;
CREATE INDEX cv_col ON cv USING sift_col (id, g, v, t);
NOTICE:  sift_col index "cv_col": 1 automatic choice (track_changes)
DETAIL:  track_changes = id
HINT:  Reasons, costs and how to turn each off: SELECT * FROM sift.index_choices('cv_col');
SELECT sift.col_verify('cv_col', true);
 col_verify 
------------
 
(1 row)

SET sift.test_col_verify_inval = on;
SELECT sift.col_verify('cv_col', true);
 col_verify 
------------
 
(1 row)

SELECT sift.col_verify('cv_col', true);
 col_verify 
------------
 
(1 row)

RESET sift.test_col_verify_inval;
SELECT sift.col_verify('cv_col', true);
 col_verify 
------------
 
(1 row)

DROP TABLE cv;
-- A toasted value is read through the lock of the toast table, which processes the invalidation messages: the entry is reloaded in the middle of a
-- tuple. A server built with assertions can do it at every such point (debug_discard_caches); the others skip the setting.
SELECT coalesce((SELECT max_val::int > 0 FROM pg_settings WHERE name = 'debug_discard_caches'), false) AS discard \gset
CREATE TABLE cvt (id int, t text);
INSERT INTO cvt SELECT i, (SELECT string_agg(md5(i::text || j), ' ') FROM generate_series(1, 200) j) FROM generate_series(1, 30) i;
SELECT count(*) AS toasted FROM cvt WHERE pg_column_toast_chunk_id(t) IS NOT NULL;
 toasted 
---------
      30
(1 row)

CREATE INDEX cvt_col ON cvt USING sift_col (id, t);
NOTICE:  sift_col index "cvt_col": 1 advice (track_changes)
DETAIL:  advice: track_changes = the table has no one-column primary key
HINT:  Reasons, costs and how to turn each off: SELECT * FROM sift.index_choices('cvt_col');
\if :discard
SET debug_discard_caches = 1;
\endif
SELECT sift.col_verify('cvt_col', true);
 col_verify 
------------
 
(1 row)

\if :discard
RESET debug_discard_caches;
\endif
DROP TABLE cvt;
DROP EXTENSION pg_sift_test, pg_sift;