Parsed test spec with 3 sessions

starting permutation: s2v s2x s3read s2m s2rec s2v s2size s3c s2v s2size s2check
step s2v: VACUUM iso_tr;
step s2x: SELECT txid_current() > 0 AS xid_used;
xid_used
--------
t       
(1 row)

step s3read: BEGIN; SELECT count(*) AS hits FROM iso_tr WHERE body @@> 'common';
hits
----
3000
(1 row)

step s2m: SELECT sift.merge('iso_tr_idx', true) > 0 AS merged;
merged
------
t     
(1 row)

step s2rec: CREATE TABLE iso_tr_size AS SELECT relation_blocks AS blocks FROM sift.index_info('iso_tr_idx');
step s2v: VACUUM iso_tr;
step s2size: SELECT i.relation_blocks = s.blocks AS unchanged, i.relation_blocks < s.blocks AS shrunk, i.relation_blocks = i.high_water AS sized
			  FROM sift.index_info('iso_tr_idx') i, iso_tr_size s;
unchanged|shrunk|sized
---------+------+-----
t        |f     |t    
(1 row)

step s3c: COMMIT;
step s2v: VACUUM iso_tr;
step s2size: SELECT i.relation_blocks = s.blocks AS unchanged, i.relation_blocks < s.blocks AS shrunk, i.relation_blocks = i.high_water AS sized
			  FROM sift.index_info('iso_tr_idx') i, iso_tr_size s;
unchanged|shrunk|sized
---------+------+-----
f        |t     |t    
(1 row)

step s2check: SELECT iso_agree('iso_tr', 'common') AS agree, iso_agree('iso_tr', 'appended') AS agree_appended, iso_verify('iso_tr_idx') AS verified;
agree|agree_appended|verified
-----+--------------+--------
t    |t             |t       
(1 row)


starting permutation: s3snap s2v s1i s3c s2p s2rec s2v s2size s1j s2check
step s3snap: BEGIN ISOLATION LEVEL REPEATABLE READ; SELECT count(*) > 0 AS snapshot FROM iso_tr;
snapshot
--------
t       
(1 row)

step s2v: VACUUM iso_tr;
step s1i: INSERT INTO iso_tr SELECT g, 'common appended ' || g FROM generate_series(100001, 140000) g;
step s3c: COMMIT;
step s2p: SELECT sift.promote('iso_tr_idx') > 0 AS promoted;
promoted
--------
t       
(1 row)

step s2rec: CREATE TABLE iso_tr_size AS SELECT relation_blocks AS blocks FROM sift.index_info('iso_tr_idx');
step s2v: VACUUM iso_tr;
step s2size: SELECT i.relation_blocks = s.blocks AS unchanged, i.relation_blocks < s.blocks AS shrunk, i.relation_blocks = i.high_water AS sized
			  FROM sift.index_info('iso_tr_idx') i, iso_tr_size s;
unchanged|shrunk|sized
---------+------+-----
f        |t     |t    
(1 row)

step s1j: INSERT INTO iso_tr SELECT g, 'common again ' || g FROM generate_series(150001, 150100) g;
step s2check: SELECT iso_agree('iso_tr', 'common') AS agree, iso_agree('iso_tr', 'appended') AS agree_appended, iso_verify('iso_tr_idx') AS verified;
agree|agree_appended|verified
-----+--------------+--------
t    |t             |t       
(1 row)