Parsed test spec with 2 sessions

starting permutation: s2lock s1exec s2addp s2unlock
step s2lock: SELECT pg_advisory_lock(12345);
pg_advisory_lock
----------------
                
(1 row)

step s1exec: LOAD 'delay_execution';
		  SET delay_execution.post_planning_lock_id = 12345;
		  SELECT * FROM foo WHERE a <> 1 AND a <> (SELECT 3); <waiting ...>
step s2addp: CREATE TABLE foo2 (LIKE foo);
		  ALTER TABLE foo ATTACH PARTITION foo2 FOR VALUES IN (2);
		  INSERT INTO foo VALUES (2, 'ADD2');
step s2unlock: SELECT pg_advisory_unlock(12345);
pg_advisory_unlock
------------------
t                 
(1 row)

step s1exec: <... completed>
a|b  
-+---
4|GHI
(1 row)