Parsed test spec with 3 sessions

starting permutation: s1rr s2del s3v s1q s1c s1q
step s1rr: BEGIN ISOLATION LEVEL REPEATABLE READ; SELECT count(*) FROM iso_tn;
count
-----
30000
(1 row)

step s2del: DELETE FROM iso_tn WHERE id > 29000 OR id < 1000;
step s3v: VACUUM iso_tn;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)

step s1c: COMMIT;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
28001|t   |top-n
(1 row)


starting permutation: s1rr s2ins s3v s1q s1c s1q
step s1rr: BEGIN ISOLATION LEVEL REPEATABLE READ; SELECT count(*) FROM iso_tn;
count
-----
30000
(1 row)

step s2ins: INSERT INTO iso_tn (id, g, seq) SELECT 40000 + i, i % 7, 40000 + i FROM generate_series(1, 3000) i;
step s3v: VACUUM iso_tn;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)

step s1c: COMMIT;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
33000|t   |top-n
(1 row)


starting permutation: s1rr s2upd s2low s3v s1q s1c s1q
step s1rr: BEGIN ISOLATION LEVEL REPEATABLE READ; SELECT count(*) FROM iso_tn;
count
-----
30000
(1 row)

step s2upd: UPDATE iso_tn SET seq = seq + 1000000 WHERE id % 1500 = 0;
step s2low: UPDATE iso_tn SET seq = -seq WHERE id % 1500 = 1;
step s3v: VACUUM iso_tn;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)

step s1c: COMMIT;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)


starting permutation: s2upd s2low s1q s3v s1q
step s2upd: UPDATE iso_tn SET seq = seq + 1000000 WHERE id % 1500 = 0;
step s2low: UPDATE iso_tn SET seq = -seq WHERE id % 1500 = 1;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)

step s3v: VACUUM iso_tn;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)


starting permutation: s2b s2del s3v s1q s2c s1q
step s2b: BEGIN;
step s2del: DELETE FROM iso_tn WHERE id > 29000 OR id < 1000;
step s3v: VACUUM iso_tn;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)

step s2c: COMMIT;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
28001|t   |top-n
(1 row)


starting permutation: s2b s2upd s2low s3v s1q s2c s1q
step s2b: BEGIN;
step s2upd: UPDATE iso_tn SET seq = seq + 1000000 WHERE id % 1500 = 0;
step s2low: UPDATE iso_tn SET seq = -seq WHERE id % 1500 = 1;
step s3v: VACUUM iso_tn;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)

step s2c: COMMIT;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)


starting permutation: s2b s2ins s3v s1q s2c s1q
step s2b: BEGIN;
step s2ins: INSERT INTO iso_tn (id, g, seq) SELECT 40000 + i, i % 7, 40000 + i FROM generate_series(1, 3000) i;
step s3v: VACUUM iso_tn;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)

step s2c: COMMIT;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
33000|t   |top-n
(1 row)


starting permutation: s2b s2del s2a s3v s1q
step s2b: BEGIN;
step s2del: DELETE FROM iso_tn WHERE id > 29000 OR id < 1000;
step s2a: ROLLBACK;
step s3v: VACUUM iso_tn;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)


starting permutation: s2b s2upd s2a s3v s1q
step s2b: BEGIN;
step s2upd: UPDATE iso_tn SET seq = seq + 1000000 WHERE id % 1500 = 0;
step s2a: ROLLBACK;
step s3v: VACUUM iso_tn;
step s1q: SELECT * FROM iso_tn_check();
    n|same|plan 
-----+----+-----
30000|t   |top-n
(1 row)