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;
?column?
--------
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;
?column?
--------
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;
?column?
--------
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;
?column?
--------
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;
?column?
--------
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;
?column?
--------
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;
?column?
--------
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;
?column?
--------
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;
?column?
--------
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;
?column?
--------
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;