Parsed test spec with 2 sessions starting permutation: wxry1 c1 r2 wyrx2 c2 step wxry1: INSERT INTO child (parent_id) VALUES (0); step c1: COMMIT; step r2: SELECT TRUE; bool ---- t (1 row) step wyrx2: DELETE FROM parent WHERE parent_id = 0; ERROR: child row exists step c2: COMMIT; starting permutation: wxry1 r2 c1 wyrx2 c2 step wxry1: INSERT INTO child (parent_id) VALUES (0); step r2: SELECT TRUE; bool ---- t (1 row) step c1: COMMIT; step wyrx2: DELETE FROM parent WHERE parent_id = 0; ERROR: could not serialize access due to read/write dependencies among transactions step c2: COMMIT; starting permutation: wxry1 r2 wyrx2 c1 c2 step wxry1: INSERT INTO child (parent_id) VALUES (0); step r2: SELECT TRUE; bool ---- t (1 row) step wyrx2: DELETE FROM parent WHERE parent_id = 0; step c1: COMMIT; step c2: COMMIT; ERROR: could not serialize access due to read/write dependencies among transactions starting permutation: wxry1 r2 wyrx2 c2 c1 step wxry1: INSERT INTO child (parent_id) VALUES (0); step r2: SELECT TRUE; bool ---- t (1 row) step wyrx2: DELETE FROM parent WHERE parent_id = 0; step c2: COMMIT; step c1: COMMIT; ERROR: could not serialize access due to read/write dependencies among transactions starting permutation: r2 wxry1 c1 wyrx2 c2 step r2: SELECT TRUE; bool ---- t (1 row) step wxry1: INSERT INTO child (parent_id) VALUES (0); step c1: COMMIT; step wyrx2: DELETE FROM parent WHERE parent_id = 0; ERROR: could not serialize access due to read/write dependencies among transactions step c2: COMMIT; starting permutation: r2 wxry1 wyrx2 c1 c2 step r2: SELECT TRUE; bool ---- t (1 row) step wxry1: INSERT INTO child (parent_id) VALUES (0); step wyrx2: DELETE FROM parent WHERE parent_id = 0; step c1: COMMIT; step c2: COMMIT; ERROR: could not serialize access due to read/write dependencies among transactions starting permutation: r2 wxry1 wyrx2 c2 c1 step r2: SELECT TRUE; bool ---- t (1 row) step wxry1: INSERT INTO child (parent_id) VALUES (0); step wyrx2: DELETE FROM parent WHERE parent_id = 0; step c2: COMMIT; step c1: COMMIT; ERROR: could not serialize access due to read/write dependencies among transactions starting permutation: r2 wyrx2 wxry1 c1 c2 step r2: SELECT TRUE; bool ---- t (1 row) step wyrx2: DELETE FROM parent WHERE parent_id = 0; step wxry1: INSERT INTO child (parent_id) VALUES (0); step c1: COMMIT; step c2: COMMIT; ERROR: could not serialize access due to read/write dependencies among transactions starting permutation: r2 wyrx2 wxry1 c2 c1 step r2: SELECT TRUE; bool ---- t (1 row) step wyrx2: DELETE FROM parent WHERE parent_id = 0; step wxry1: INSERT INTO child (parent_id) VALUES (0); step c2: COMMIT; step c1: COMMIT; ERROR: could not serialize access due to read/write dependencies among transactions starting permutation: r2 wyrx2 c2 wxry1 c1 step r2: SELECT TRUE; bool ---- t (1 row) step wyrx2: DELETE FROM parent WHERE parent_id = 0; step c2: COMMIT; step wxry1: INSERT INTO child (parent_id) VALUES (0); ERROR: parent row missing step c1: COMMIT;