Horton

Re: Logical Replication of sequences

vignesh C <vignesh21@gmail.com>

View thread
From: vignesh C <vignesh21@gmail.com>
To: shveta malik <shveta.malik@gmail.com>
Cc: Peter Smith <smithpb2250@gmail.com>, 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>
Date: 2024-07-29T10:48:33Z
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 Thu, 25 Jul 2024 at 15:41, shveta malik <shveta.malik@gmail.com> wrote:
>
> On Thu, Jul 25, 2024 at 12:08 PM shveta malik <shveta.malik@gmail.com> wrote:
> >
> > On Thu, Jul 25, 2024 at 9:06 AM vignesh C <vignesh21@gmail.com> wrote:
> > >
> > > The attached v20240725 version patch has the changes for the same.
> >
> > Thank You for addressing the comments. Please review below issues:
> >
> > 1) Sub ahead of pub due to wrong initial sync of last_value for
> > non-incremented sequences. Steps at [1]
> > 2) Sequence's min value is not honored on sub during replication. Steps at [2]
>
> One more issue:
> 3)  Sequence datatype's range is not honored on sub during
> replication, while it is honored for tables.
>
>
> Behaviour for tables:
> ---------------------
> Pub: create table tab1( i integer);
> Sub: create table tab1( i smallint);
>
> Pub: insert into tab1 values(generate_series(1, 32768));
>
> Error on sub:
> 2024-07-25 10:38:06.446 IST [178680] ERROR:  value "32768" is out of
> range for type smallint
>
> ---------------------
> Behaviour for sequences:
> ---------------------
>
> Pub:
> CREATE SEQUENCE myseq_i as integer INCREMENT 10000 START 1;
>
> Sub:
> CREATE SEQUENCE myseq_i as smallint INCREMENT 10000 START 1;
>
> Pub:
> SELECT nextval('myseq_i');
> SELECT nextval('myseq_i');
> SELECT nextval('myseq_i');
> SELECT nextval('myseq_i');
> SELECT nextval('myseq_i'); -->brings value to 40001
>
> Sub:
> ALTER SUBSCRIPTION sub1 REFRESH PUBLICATION SEQUENCES;
> SELECT * from pg_sequences;  -->last_val reached till 40001, while the
> range is till  32767.

This issue is addressed in the v20240730_2 version patch attached at [1].
[1] - https://www.postgresql.org/message-id/CALDaNm3%2BXzHAbgyn8gmbBLK5goyv_uyGgHEsTQxRZ8bVk6nAEg%40mail.gmail.com

Regards,
Vignesh