RE: logical decoding and replication of sequences, take 2

On Wednesday, August 16, 2023 10:27 PM Tomas Vondra <tomas(dot)vondra(at)enterprisedb(dot)com> wrote:

Hi,

>
>
> I guess we could update the origin, per attached 0004. We don't have
> timestamp to set replorigin_session_origin_timestamp, but it seems we don't
> need that.
>
> The attached patch merges the earlier improvements, except for the part that
> experimented with adding a "fake" transaction (which turned out to have a
> number of difficult issues).

I tried to test the patch and found a crash when calling
pg_logical_slot_get_changes() to consume sequence changes.

Steps:
----
create table t1_seq(a int);
create sequence seq1;
SELECT 'init' FROM pg_create_logical_replication_slot('test_slot',
'test_decoding', false, true);
INSERT INTO t1_seq SELECT nextval('seq1') FROM generate_series(1,100);
SELECT data FROM pg_logical_slot_get_changes('test_slot', NULL, NULL,
'include-xids', 'false', 'skip-empty-xacts', '1');
----

Attach the backtrace in bt.txt.

Best Regards,
Hou zj