-- With the maintenance worker on (sift.async_maintenance, the default) the VACUUM asks it to promote the write buffer while the session calls the rewrite: whichever of the two
-- gets the maintenance lock first, the segments the rewrite takes first (the overlays alone, the dirty ones) are not what decides whether the key is chosen again from the data
-- (col_key_cut_redecide is the same rewrite with the worker off). The call is repeated until the lock is the session's; the test waits for the option, not for the clock.
CREATE EXTENSION pg_sift;
SET sift.test_col_net = off;	-- this test is of the dirty units and their rewrite (col_net_agg is of the sidecar VACUUM writes for them)
SET client_min_messages = warning;
SET max_parallel_workers_per_gather = 0;
SET max_parallel_maintenance_workers = 0;
SET sift.col_auto_merge = off;

CREATE TABLE rc (id int PRIMARY KEY, tenant_id int, foreign_id int, counter_a int, updated_at timestamp, pad text);
INSERT INTO rc SELECT i, i / 150, 1 + i % 12, hashint4(i) & 1048575, TIMESTAMP '2026-01-01' + (hashint4(i + 7) & 16777215) * INTERVAL '1 second', repeat('x', 100)
FROM generate_series(1, 120000) i;
VACUUM ANALYZE rc;
CREATE INDEX rc_ix ON rc USING sift_col (id, tenant_id, foreign_id, counter_a, updated_at) WITH (dead_rewrite_pct = 50);
-- the same columns with the key the user wrote
CREATE INDEX rc_off ON rc USING sift_col (id, tenant_id, foreign_id, counter_a, updated_at) WITH (key_cut = 'off');
-- built on rows in the order of the tenants: no cut
SELECT reloptions::text ~ 'key_cut' AS cut_at_build FROM pg_class WHERE relname = 'rc_ix';

-- rows of every tenant appended at the end of the heap, a tenth of the rows deleted
INSERT INTO rc SELECT i, (hashint4(i) & 2147483647) % 800, 1 + i % 12, hashint4(i) & 1048575, TIMESTAMP '2026-01-01' + (hashint4(i + 7) & 16777215) * INTERVAL '1 second', repeat('x', 100)
FROM generate_series(120001, 240000) i;
DELETE FROM rc WHERE id % 10 = 3;
-- the workers of the writes above hold the horizon of the rows the VACUUM removes while they run (the units of a rewrite are dirty by the rows it removes)
DO $$ BEGIN
	FOR i IN 1..600 LOOP
		EXIT WHEN NOT EXISTS (SELECT 1 FROM pg_stat_activity WHERE pid <> pg_backend_pid() AND backend_xmin IS NOT NULL);
		PERFORM pg_sleep(0.1);
		COMMIT;
	END LOOP;
END $$;
VACUUM ANALYZE rc;
DO $$ BEGIN
	FOR i IN 1..600 LOOP
		PERFORM sift.col_maintain('rc_ix');
		COMMIT;
		EXIT WHEN (SELECT reloptions::text ~ 'key_cut=auto: foreign_id' FROM pg_class WHERE relname = 'rc_ix');
		PERFORM pg_sleep(0.1);
	END LOOP;
END $$;
SELECT reloptions::text ~ 'key_cut=auto: foreign_id' AS cut_after_rewrite FROM pg_class WHERE relname = 'rc_ix';
SELECT sift.col_verify('rc_ix');

SELECT count(*) AS n, sum(counter_a) AS s, count(DISTINCT tenant_id) AS t FROM rc WHERE foreign_id = 5 \gset maint_
SET sift.enable_agg = off;
SELECT count(*) = :maint_n AND sum(counter_a) = :maint_s AND count(DISTINCT tenant_id) = :maint_t AS same_answers FROM rc WHERE foreign_id = 5;
RESET sift.enable_agg;

DROP TABLE rc;
DROP EXTENSION pg_sift;