Parsed test spec with 3 sessions

starting permutation: s3o s1b s1i s2r s3m s1j s1c s2q s2c s3p s3v
step s3o: SELECT coalesce(reloptions::text, '') AS before FROM pg_class WHERE relname = 'iso_mk_idx';
before            
------------------
{key_columns=auto}
(1 row)

step s1b: BEGIN;
step s1i: INSERT INTO iso_mk SELECT g, g % 600, g % 100, repeat('p', 200) FROM generate_series(30001, 30400) g;
step s2r: BEGIN ISOLATION LEVEL REPEATABLE READ; SELECT count(*) AS rows_seen FROM iso_mk;
rows_seen
---------
    30400
(1 row)

step s3m: SELECT sift.col_merge('iso_mk_idx', true) > 0 AS merged;
merged
------
t     
(1 row)

step s1j: INSERT INTO iso_mk SELECT g, g % 600, g % 100, repeat('p', 200) FROM generate_series(30401, 30800) g;
step s1c: COMMIT;
step s2q: SELECT agree FROM iso_mk_q();
agree
-----
t    
(1 row)

step s2c: COMMIT;
step s3p: SELECT reloptions::text AS after FROM pg_class WHERE relname = 'iso_mk_idx';
after                       
----------------------------
{"key_columns=auto: set_id"}
(1 row)

step s3v: SELECT 1 AS verified FROM (SELECT sift.col_verify('iso_mk_idx', true)) v;
verified
--------
       1
(1 row)