Re: Logical Replication of sequences

vignesh C <vignesh21@gmail.com>

From: vignesh C <vignesh21@gmail.com>

To: Chao Li <li.evan.chao@gmail.com>

Cc: shveta malik <shveta.malik@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Shinya Kato <shinya11.kato@gmail.com>, Peter Smith <smithpb2250@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, Dilip Kumar <dilipbalaut@gmail.com>, Shlok Kyal <shlok.kyal.oss@gmail.com>, Nisha Moond <nisha.moond412@gmail.com>, Peter Eisentraut <peter@eisentraut.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Euler Taveira <euler@eulerto.com>, Michael Paquier <michael@paquier.xyz>, "Jonathan S. Katz" <jkatz@postgresql.org>

Date: 2025-11-11T11:10:32Z

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 →

Doc: Add documentation for sequence synchronization.
- 55cefadde874 19 (unreleased) landed
Remove unused assignment in CREATE PUBLICATION grammar.
- bfb7419b0bbe 19 (unreleased) landed
Add seq_sync_error_count to subscription statistics.
- f6a4c498dcf6 19 (unreleased) landed
Fix few issues in commit 5509055d69.
- 5a4eba558aa7 19 (unreleased) landed
Add sequence synchronization for logical replication.
- 5509055d6956 19 (unreleased) landed
Add worker type argument to logical replication worker functions.
- 3e8e05596a02 19 (unreleased) landed
Introduce "REFRESH SEQUENCES" for subscriptions.
- f0b3573c3aac 19 (unreleased) landed
Refactor logical worker synchronization code into a separate file.
- 41c674d2e31e 19 (unreleased) landed
Standardize use of REFRESH PUBLICATION in code and messages.
- 2436b8c047ff 19 (unreleased) landed
Add "ALL SEQUENCES" support to publications.
- 96b378497346 19 (unreleased) landed
Expose sequence page LSN via pg_get_sequence_data.
- b93172ca59f4 19 (unreleased) landed
Resume conflict-relevant data retention automatically.
- 0d48d393d465 19 (unreleased) cited
Post-commit review fixes for 228c370868.
- 1f7e9ba3ac4e 19 (unreleased) cited
Generate GUC tables from .dat file
- 63599896545c 19 (unreleased) cited

Attachments

v20251111-0001-Documentation-for-sequence-synchronization.patch (text/x-patch) patch v20251111-0001

On Tue, 11 Nov 2025 at 11:23, Chao Li <li.evan.chao@gmail.com> wrote:
>
> Hi Vignesh,
>
> A few more comments:
>
> > On Nov 7, 2025, at 22:47, vignesh C <vignesh21@gmail.com> wrote:
> >
> > The attached v20251107_2 version patch has the changes for the same.
> >
> > Regards,
> > Vignesh
> > <v20251107_2-0001-Documentation-for-sequence-synchronizati.patch>
>
> 1
> ```
> -        Currently, there can be only one synchronization worker per table.
> +        Currently, there can be only one table synchronization worker per table
> +        and one sequence synchronization worker to synchronize all sequences.
> ```
>
> Feels like this statement is not accurate and leaves an impression that a table has a fixed work to serve it. So I think we can enhance this statement a little bit as:
>
> ```
> Currently, only one table synchronization worker runs per table, and
> only one sequence synchronization worker runs per subscription at a time.
> ```

Changed it slightly.

> 2
> ```
> +<programlisting>
> +/* sub # */ CREATE SEQUENCE s1 START WITH 10 INCREMENT BY 1
> +/* sub # */ CREATE SEQUENCE s2 START WITH 100 INCREMENT BY 10;
> +</programlisting></para>
> ```
>
> Missed semi-colon for the first SQL statement.

Modified

> 3
> ```
> +<programlisting>
> +/* sub # */ SELECT srrelid::regclass, srsublsn FROM pg_subscription_rel ;
> ```
>
> Unneeded white-space before the semi-colon.

Modified

> 4
> ```
> +/* sub # */ SELECT * FROM s2
> + last_value | log_cnt | is_called
> +------------+---------+-----------
> +        610 |       0 | t
> +(1 row)
> ```
>
> Again, missed semi-colon.

Modified

The attached v20251111 version patch has the changes for the same.

Regards,
Vignesh