Parsed test spec with 2 sessions

starting permutation: s1-begin s1-upd-ins s2-result s1-commit s2-result
step s1-begin: BEGIN;
step s1-upd-ins: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED THEN UPDATE SET t2 = t2 + 1
   WHEN NOT MATCHED THEN INSERT VALUES(s1, s2);

step s2-result: SELECT * FROM prept ORDER BY 1;
 t1|t2
---------------------------------------------------------------------
100| 0
(1 row)

step s1-commit: COMMIT;
step s2-result: SELECT * FROM prept ORDER BY 1;
 t1|t2
---------------------------------------------------------------------
100| 1
200| 0
(2 rows)


starting permutation: s1-begin s1-upd-ins s2-begin s2-upd-del s1-commit s2-commit s2-result
step s1-begin: BEGIN;
step s1-upd-ins: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED THEN UPDATE SET t2 = t2 + 1
   WHEN NOT MATCHED THEN INSERT VALUES(s1, s2);

step s2-begin: BEGIN;
step s2-upd-del: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED AND prept.t2 = 0 THEN DELETE
   WHEN MATCHED THEN UPDATE SET t2 = t2 + 1;
 <waiting ...>
step s1-commit: COMMIT;
step s2-upd-del: <... completed>
step s2-commit: COMMIT;
step s2-result: SELECT * FROM prept ORDER BY 1;
 t1|t2
---------------------------------------------------------------------
100| 2
(1 row)


starting permutation: s2-begin s2-upd-del s1-begin s1-upd-ins s2-commit s1-commit s2-result
step s2-begin: BEGIN;
step s2-upd-del: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED AND prept.t2 = 0 THEN DELETE
   WHEN MATCHED THEN UPDATE SET t2 = t2 + 1;

step s1-begin: BEGIN;
step s1-upd-ins: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED THEN UPDATE SET t2 = t2 + 1
   WHEN NOT MATCHED THEN INSERT VALUES(s1, s2);
 <waiting ...>
step s2-commit: COMMIT;
step s1-upd-ins: <... completed>
step s1-commit: COMMIT;
step s2-result: SELECT * FROM prept ORDER BY 1;
 t1|t2
---------------------------------------------------------------------
100| 0
200| 0
(2 rows)


starting permutation: s1-begin s1-upd-ins s2-begin s2-upd s1-commit s2-commit s2-result
step s1-begin: BEGIN;
step s1-upd-ins: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED THEN UPDATE SET t2 = t2 + 1
   WHEN NOT MATCHED THEN INSERT VALUES(s1, s2);

step s2-begin: BEGIN;
step s2-upd: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED THEN UPDATE SET t2 = t2 + 1;
 <waiting ...>
step s1-commit: COMMIT;
step s2-upd: <... completed>
step s2-commit: COMMIT;
step s2-result: SELECT * FROM prept ORDER BY 1;
 t1|t2
---------------------------------------------------------------------
100| 2
200| 1
(2 rows)


starting permutation: s2-begin s2-ins s1-begin s1-del s2-upd s2-result s2-commit s1-commit s2-result
step s2-begin: BEGIN;
step s2-ins: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN NOT MATCHED THEN INSERT VALUES(s1, s2);

step s1-begin: BEGIN;
step s1-del: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED THEN DELETE;
 <waiting ...>
step s2-upd: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED THEN UPDATE SET t2 = t2 + 1;

step s2-result: SELECT * FROM prept ORDER BY 1;
 t1|t2
---------------------------------------------------------------------
100| 1
200| 1
(2 rows)

step s2-commit: COMMIT;
step s1-del: <... completed>
step s1-commit: COMMIT;
step s2-result: SELECT * FROM prept ORDER BY 1;
t1|t2
---------------------------------------------------------------------
(0 rows)


starting permutation: s1-begin s1-del-ins s2-begin s2-upd s1-result s1-ins s1-commit s2-upd s2-commit s2-result
step s1-begin: BEGIN;
step s1-del-ins: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED THEN DELETE
   WHEN NOT MATCHED THEN INSERT VALUES(s1, s2);

step s2-begin: BEGIN;
step s2-upd: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED THEN UPDATE SET t2 = t2 + 1;
 <waiting ...>
step s1-result: SELECT * FROM prept ORDER BY 1;
 t1|t2
---------------------------------------------------------------------
200| 0
(1 row)

step s1-ins: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN NOT MATCHED THEN INSERT VALUES(s1, s2);

step s1-commit: COMMIT;
step s2-upd: <... completed>
step s2-upd: MERGE INTO prept USING preps ON prept.t1 = preps.s1
   WHEN MATCHED THEN UPDATE SET t2 = t2 + 1;

step s2-commit: COMMIT;
step s2-result: SELECT * FROM prept ORDER BY 1;
 t1|t2
---------------------------------------------------------------------
100| 2
200| 2
(2 rows)