Horton

Re: Logical Replication of sequences

shveta malik <shveta.malik@gmail.com>

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From: shveta malik <shveta.malik@gmail.com>
To: Peter Smith <smithpb2250@gmail.com>, vignesh C <vignesh21@gmail.com>
Cc: Shlok Kyal <shlok.kyal.oss@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Peter Eisentraut <peter@eisentraut.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Euler Taveira <euler@eulerto.com>, Michael Paquier <michael@paquier.xyz>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, Hou, Zhijie/侯 志杰 <houzj.fnst@fujitsu.com>, "Jonathan S. Katz" <jkatz@postgresql.org>, shveta malik <shveta.malik@gmail.com>
Date: 2024-07-24T06:22:49Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Doc: Add documentation for sequence synchronization.

  2. Remove unused assignment in CREATE PUBLICATION grammar.

  3. Add seq_sync_error_count to subscription statistics.

  4. Fix few issues in commit 5509055d69.

  5. Add sequence synchronization for logical replication.

  6. Add worker type argument to logical replication worker functions.

  7. Introduce "REFRESH SEQUENCES" for subscriptions.

  8. Refactor logical worker synchronization code into a separate file.

  9. Standardize use of REFRESH PUBLICATION in code and messages.

  10. Add "ALL SEQUENCES" support to publications.

  11. Expose sequence page LSN via pg_get_sequence_data.

  12. Resume conflict-relevant data retention automatically.

  13. Post-commit review fixes for 228c370868.

  14. Generate GUC tables from .dat file

On Wed, Jul 24, 2024 at 9:17 AM Peter Smith <smithpb2250@gmail.com> wrote:
>

I had a look at patches v20240720* (considering these as the latest
one) and tried to do some basic testing (WIP). Few comments:

1)
I see 'last_value' is updated wrongly after create-sub.  Steps:

-----------
pub:
CREATE SEQUENCE myseq0 INCREMENT 5 START 100;
SELECT nextval('myseq0');
SELECT nextval('myseq0');
--last_value on pub is 105
select * from pg_sequences;
create publication pub1 for all tables, sequences;

Sub:
CREATE SEQUENCE myseq0 INCREMENT 5 START 100;
create subscription sub1 connection 'dbname=postgres host=localhost
user=shveta port=5433' publication pub1;

--check 'r' state is reached
select pc.relname, pr.srsubstate, pr.srsublsn from pg_subscription_rel
pr, pg_class pc where (pr.srrelid = pc.oid);

--check 'last_value', it shows some random value as 136
select * from pg_sequences;
-----------

2)
I can use 'for all sequences' only with 'for all tables' and can not
use it with the below. Shouldn't it be allowed?

create publication pub2 for tables in schema public, for all sequences;
create publication pub2 for table t1, for all sequences;

3)
preprocess_pub_all_objtype_list():
Do we need 'alltables_specified' and 'allsequences_specified' ? Can't
we make a repetition check using *alltables and *allsequences?

4) patch02's commit msg says : 'Additionally, a new system view,
pg_publication_sequences, has been introduced'
But it is not part of patch002.

thanks
Shveta