Parsed test spec with 3 sessions starting permutation: s1a s2a s3a s1b s2b s3b step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE LIMIT 1; id data status 1 foo NEW step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE LIMIT 1; <waiting ...> step s3a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1; id data status 2 bar NEW step s1b: COMMIT; step s2a: <... completed> id data status 1 foo NEW step s2b: COMMIT; step s3b: COMMIT;