1Parsed test spec with 3 sessions 2 3starting permutation: sl1_prep upd_getlock sl1_exec upd_doupdate lk1_doforshare upd_releaselock 4step sl1_prep: 5 PREPARE sl1_run AS SELECT id FROM test_nowait WHERE pg_advisory_lock(0) is not null FOR UPDATE NOWAIT; 6 7step upd_getlock: 8 SELECT pg_advisory_lock(0); 9 10pg_advisory_lock 11---------------- 12 13(1 row) 14 15step sl1_exec: 16 BEGIN ISOLATION LEVEL READ COMMITTED; 17 EXECUTE sl1_run; 18 SELECT xmin, xmax, ctid, * FROM test_nowait; 19 <waiting ...> 20step upd_doupdate: 21 BEGIN ISOLATION LEVEL READ COMMITTED; 22 UPDATE test_nowait SET value = value WHERE id % 2 = 0; 23 COMMIT; 24 25step lk1_doforshare: 26 BEGIN ISOLATION LEVEL READ COMMITTED; 27 SELECT id FROM test_nowait WHERE id % 2 = 0 FOR SHARE; 28 29id 30-- 31 2 32(1 row) 33 34step upd_releaselock: 35 SELECT pg_advisory_unlock(0); 36 37pg_advisory_unlock 38------------------ 39t 40(1 row) 41 42step sl1_exec: <... completed> 43ERROR: could not obtain lock on row in relation "test_nowait" 44