Parsed test spec with 2 sessions starting permutation: s1a s1b s2a s2b step s1a: SELECT * FROM foo FOR UPDATE NOWAIT; id data 1 x step s1b: COMMIT; step s2a: SELECT * FROM foo FOR UPDATE NOWAIT; id data 1 x step s2b: COMMIT; starting permutation: s1a s2a s1b s2b step s1a: SELECT * FROM foo FOR UPDATE NOWAIT; id data 1 x step s2a: SELECT * FROM foo FOR UPDATE NOWAIT; ERROR: could not obtain lock on row in relation "foo" step s1b: COMMIT; step s2b: COMMIT; starting permutation: s1a s2a s2b s1b step s1a: SELECT * FROM foo FOR UPDATE NOWAIT; id data 1 x step s2a: SELECT * FROM foo FOR UPDATE NOWAIT; ERROR: could not obtain lock on row in relation "foo" step s2b: COMMIT; step s1b: COMMIT; starting permutation: s2a s1a s1b s2b step s2a: SELECT * FROM foo FOR UPDATE NOWAIT; id data 1 x step s1a: SELECT * FROM foo FOR UPDATE NOWAIT; ERROR: could not obtain lock on row in relation "foo" step s1b: COMMIT; step s2b: COMMIT; starting permutation: s2a s1a s2b s1b step s2a: SELECT * FROM foo FOR UPDATE NOWAIT; id data 1 x step s1a: SELECT * FROM foo FOR UPDATE NOWAIT; ERROR: could not obtain lock on row in relation "foo" step s2b: COMMIT; step s1b: COMMIT; starting permutation: s2a s2b s1a s1b step s2a: SELECT * FROM foo FOR UPDATE NOWAIT; id data 1 x step s2b: COMMIT; step s1a: SELECT * FROM foo FOR UPDATE NOWAIT; id data 1 x step s1b: COMMIT;