Parsed test spec with 3 sessions starting permutation: s2rx s2ry s1ry s1wy s1c s2wx s2c s3c step s2rx: SELECT balance FROM bank_account WHERE id = 'X'; balance 0 step s2ry: SELECT balance FROM bank_account WHERE id = 'Y'; balance 0 step s1ry: SELECT balance FROM bank_account WHERE id = 'Y'; balance 0 step s1wy: UPDATE bank_account SET balance = 20 WHERE id = 'Y'; step s1c: COMMIT; step s2wx: UPDATE bank_account SET balance = -11 WHERE id = 'X'; step s2c: COMMIT; step s3c: COMMIT; starting permutation: s2rx s2ry s1ry s1wy s1c s3r s3c s2wx step s2rx: SELECT balance FROM bank_account WHERE id = 'X'; balance 0 step s2ry: SELECT balance FROM bank_account WHERE id = 'Y'; balance 0 step s1ry: SELECT balance FROM bank_account WHERE id = 'Y'; balance 0 step s1wy: UPDATE bank_account SET balance = 20 WHERE id = 'Y'; step s1c: COMMIT; step s3r: SELECT id, balance FROM bank_account WHERE id IN ('X', 'Y') ORDER BY id; id balance X 0 Y 20 step s3c: COMMIT; step s2wx: UPDATE bank_account SET balance = -11 WHERE id = 'X'; ERROR: could not serialize access due to read/write dependencies among transactions