-- sift_conn_inserted_since(stamp): could a row have been inserted into the parent index by a transaction at or after the stamp's horizon? False only when every segment says its
-- inserters finished before the horizon and the write buffer holds no live record from the horizon on (an aborted transaction does not count; the caller's own insert does).
CREATE EXTENSION pg_sift;
CREATE EXTENSION pg_sift_test;
SET max_parallel_workers_per_gather = 0;
CREATE TABLE dim_a (id int PRIMARY KEY, category_id int NOT NULL, label text) WITH (autovacuum_enabled = false);
INSERT INTO dim_a SELECT i, i % 10, 'l' || i FROM generate_series(1, 1000) i;
CREATE INDEX dim_a_col ON dim_a USING sift_col (id, category_id, label);
NOTICE:  sift_col index "dim_a_col": 1 automatic choice (track_changes)
DETAIL:  track_changes = id
HINT:  Reasons, costs and how to turn each off: SELECT * FROM sift.index_choices('dim_a_col');
SELECT sift._test_conn_enable('dim_a_col') <> 0 AS journal;
 journal 
---------
 t
(1 row)

CREATE FUNCTION ins(lin int8, hor xid) RETURNS bool LANGUAGE sql AS $$ SELECT sift._test_conn_inserted_since('dim_a_col', lin, hor) $$;
-- nothing written since the stamp
SELECT lineage AS lin, horizon AS hor FROM sift._test_conn_take('dim_a_col') \gset
SELECT ins(:lin, :'hor') AS nothing_written;
 nothing_written 
-----------------
 f
(1 row)

-- a committed insert of a new key
INSERT INTO dim_a VALUES (2001, 1, 'new');
SELECT ins(:lin, :'hor') AS committed_insert;
 committed_insert 
------------------
 t
(1 row)

-- a stamp taken after it: the insert is before the horizon, in the write buffer
SELECT lineage AS lin, horizon AS hor FROM sift._test_conn_take('dim_a_col') \gset
SELECT ins(:lin, :'hor') AS after_the_insert;
 after_the_insert 
------------------
 f
(1 row)

-- a rolled back insert, and one rolled back to a savepoint
BEGIN;
INSERT INTO dim_a VALUES (2002, 1, 'gone');
ROLLBACK;
SELECT ins(:lin, :'hor') AS rolled_back;
 rolled_back 
-------------
 f
(1 row)

BEGIN;
SAVEPOINT s;
INSERT INTO dim_a VALUES (2003, 1, 'gone');
ROLLBACK TO s;
SELECT ins(:lin, :'hor') AS rolled_back_savepoint;
 rolled_back_savepoint 
-----------------------
 f
(1 row)

COMMIT;
SELECT ins(:lin, :'hor') AS after_the_savepoint;
 after_the_savepoint 
---------------------
 f
(1 row)

-- the transaction's own insert, before it commits, and one inside a savepoint that is released
BEGIN;
INSERT INTO dim_a VALUES (2004, 1, 'own');
SELECT ins(:lin, :'hor') AS own_insert;
 own_insert 
------------
 t
(1 row)

ROLLBACK;
SELECT ins(:lin, :'hor') AS own_insert_rolled_back;
 own_insert_rolled_back 
------------------------
 f
(1 row)

BEGIN;
SAVEPOINT s;
INSERT INTO dim_a VALUES (2005, 1, 'own');
RELEASE s;
SELECT ins(:lin, :'hor') AS savepoint_released;
 savepoint_released 
--------------------
 t
(1 row)

ROLLBACK;
-- an UPDATE writes a new version of the row: it counts (its key is in changed(S, X) as well)
UPDATE dim_a SET category_id = 7 WHERE id = 5;
SELECT ins(:lin, :'hor') AS update;
 update 
--------
 t
(1 row)

-- promotion and VACUUM move the rows into segments, which say when their inserters finished: the old stamp still sees the insert, a new one does not
SELECT sift.col_promote('dim_a_col') >= 0 AS promoted;
 promoted 
----------
 t
(1 row)

VACUUM dim_a;
SELECT ins(:lin, :'hor') AS old_stamp_after_vacuum;
 old_stamp_after_vacuum 
------------------------
 t
(1 row)

SELECT lineage AS lin2, horizon AS hor2 FROM sift._test_conn_take('dim_a_col') \gset
SELECT ins(:lin2, :'hor2') AS new_stamp_after_vacuum;
 new_stamp_after_vacuum 
------------------------
 f
(1 row)

SELECT sift.col_merge('dim_a_col', true) >= 0 AS merged;
 merged 
--------
 t
(1 row)

SELECT ins(:lin2, :'hor2') AS after_merge;
 after_merge 
-------------
 f
(1 row)

INSERT INTO dim_a VALUES (2006, 1, 'late');
SELECT ins(:lin2, :'hor2') AS after_merge_and_insert;
 after_merge_and_insert 
------------------------
 t
(1 row)

DROP FUNCTION ins(int8, xid);
DROP TABLE dim_a;
DROP EXTENSION pg_sift_test;
DROP EXTENSION pg_sift;