Parsed test spec with 2 sessions starting permutation: s1b s2b s2u1 s1u s2c s1c s1s step s1b: BEGIN ISOLATION LEVEL READ COMMITTED; step s2b: BEGIN ISOLATION LEVEL READ COMMITTED; step s2u1: UPDATE foo SET b = b || ' update2' WHERE a = 1; step s1u: UPDATE foo SET a = a + 1, b = b || ' update1' WHERE b like '%ABC%'; step s2c: COMMIT; step s1u: <... completed> step s1c: COMMIT; step s1s: SELECT tableoid::regclass, * FROM foo ORDER BY a; tableoid a b foo2 2 ABC update2 update1 starting permutation: s1b s2b s2ut1 s1ut s2c s1c s1st s1stl step s1b: BEGIN ISOLATION LEVEL READ COMMITTED; step s2b: BEGIN ISOLATION LEVEL READ COMMITTED; step s2ut1: UPDATE footrg SET b = b || ' update2' WHERE a = 1; step s1ut: UPDATE footrg SET a = a + 1, b = b || ' update1' WHERE b like '%ABC%'; step s2c: COMMIT; step s1ut: <... completed> step s1c: COMMIT; step s1st: SELECT tableoid::regclass, * FROM footrg ORDER BY a; tableoid a b footrg2 2 ABC update2 update1 step s1stl: SELECT * FROM triglog ORDER BY a; a b 1 ABC update2 trigger starting permutation: s1b s2b s2u2 s1u s2c s1c s1s step s1b: BEGIN ISOLATION LEVEL READ COMMITTED; step s2b: BEGIN ISOLATION LEVEL READ COMMITTED; step s2u2: UPDATE foo SET b = 'EFG' WHERE a = 1; step s1u: UPDATE foo SET a = a + 1, b = b || ' update1' WHERE b like '%ABC%'; step s2c: COMMIT; step s1u: <... completed> step s1c: COMMIT; step s1s: SELECT tableoid::regclass, * FROM foo ORDER BY a; tableoid a b foo1 1 EFG starting permutation: s1b s2b s2ut2 s1ut s2c s1c s1st s1stl step s1b: BEGIN ISOLATION LEVEL READ COMMITTED; step s2b: BEGIN ISOLATION LEVEL READ COMMITTED; step s2ut2: UPDATE footrg SET b = 'EFG' WHERE a = 1; step s1ut: UPDATE footrg SET a = a + 1, b = b || ' update1' WHERE b like '%ABC%'; step s2c: COMMIT; step s1ut: <... completed> step s1c: COMMIT; step s1st: SELECT tableoid::regclass, * FROM footrg ORDER BY a; tableoid a b footrg1 1 EFG step s1stl: SELECT * FROM triglog ORDER BY a; a b