-- init
\set ECHO none
-- i/o
select '12:13:'::txid_snapshot;
 txid_snapshot 
---------------
 12:13:
(1 row)

select '12:13:1,2'::txid_snapshot;
ERROR:  illegal txid_snapshot input format
-- errors
select '31:12:'::txid_snapshot;
ERROR:  illegal txid_snapshot input format
select '0:1:'::txid_snapshot;
ERROR:  illegal txid_snapshot input format
select '12:13:0'::txid_snapshot;
ERROR:  illegal txid_snapshot input format
select '12:13:2,1'::txid_snapshot;
ERROR:  illegal txid_snapshot input format
create table snapshot_test (
	nr	integer,
	snap	txid_snapshot
);
insert into snapshot_test values (1, '12:13:');
insert into snapshot_test values (2, '12:20:13,15,18');
insert into snapshot_test values (3, '100001:100009:100005,100007,100008');
select snap from snapshot_test order by nr;
                snap                
------------------------------------
 12:13:
 12:20:13,15,18
 100001:100009:100005,100007,100008
(3 rows)

select  get_snapshot_xmin(snap),
	get_snapshot_xmax(snap),
	get_snapshot_active(snap)
from snapshot_test order by nr;
 get_snapshot_xmin | get_snapshot_xmax | get_snapshot_active 
-------------------+-------------------+---------------------
                12 |                20 |                  13
                12 |                20 |                  15
                12 |                20 |                  18
            100001 |            100009 |              100005
            100001 |            100009 |              100007
            100001 |            100009 |              100008
(6 rows)

select id, txid_in_snapshot(id, snap),
       txid_not_in_snapshot(id, snap)
from snapshot_test, generate_series(11, 21) id
where nr = 2;
 id | txid_in_snapshot | txid_not_in_snapshot 
----+------------------+----------------------
 11 | t                | f
 12 | t                | f
 13 | f                | t
 14 | t                | f
 15 | f                | t
 16 | t                | f
 17 | t                | f
 18 | f                | t
 19 | t                | f
 20 | f                | t
 21 | f                | t
(11 rows)

-- test current values also
select get_current_txid() >= get_snapshot_xmin(get_current_snapshot());
 ?column? 
----------
 t
(1 row)

select get_current_txid() < get_snapshot_xmax(get_current_snapshot());
 ?column? 
----------
 t
(1 row)

select txid_in_snapshot(get_current_txid(), get_current_snapshot()),
   txid_not_in_snapshot(get_current_txid(), get_current_snapshot());
 txid_in_snapshot | txid_not_in_snapshot 
------------------+----------------------
 t                | f
(1 row)