Horton

Re: Logical Replication of sequences

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Shlok Kyal <shlok.kyal.oss@gmail.com>
Cc: vignesh C <vignesh21@gmail.com>, Chao Li <li.evan.chao@gmail.com>, shveta malik <shveta.malik@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>, 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: 2025-12-22T05:38:39Z
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, Dec 18, 2025 at 12:37 PM Shlok Kyal <shlok.kyal.oss@gmail.com> wrote:
>
> While working on another thread, I noticed a bug introduced by commit
> as part of this thread.
> In function pg_get_publication_tables, We have code:
> ```
>                      if (pub_elem->alltables)
> pub_elem_tables = GetAllPublicationRelations(RELKIND_RELATION,
>  pub_elem->pubviaroot);
> else
> {
> List     *relids,
>    *schemarelids;
>
> relids = GetPublicationRelations(pub_elem->oid,
>  pub_elem->pubviaroot ?
>  PUBLICATION_PART_ROOT :
>  PUBLICATION_PART_LEAF);
> schemarelids = GetAllSchemaPublicationRelations(pub_elem->oid,
> pub_elem->pubviaroot ?
> PUBLICATION_PART_ROOT :
> PUBLICATION_PART_LEAF);
> pub_elem_tables = list_concat_unique_oid(relids, schemarelids);
> }
> ```
>
> So, when we create an 'ALL SEQUENCE publication' and we execute
> 'SELECT * from pg_publication_tables'
> We will enter the else condition in the above code, which does not
> seem correct to me.
> It will call functions which are not required to be called. It will
> also call the function 'GetPublicationRelations' which contradicts the
> comment above this function.
>

I see that we will needlessly call GetPublicationRelations or others
for all_schema publication but is there any problem/bug due to that?
AFAICS, the function will still return correct results. Yes, there is
an argument to better performance for large numbers of all_sequence
publications and that too in DDL like Create/Alter Subscription. I am
not sure that it is really worth adding more checks at multiple places
in the code though we can improve comments atop
GetPublicationRelations. I feel if we encounter such cases in the
field then it makes sense to add these additional optimizations at
various places.

-- 
With Regards,
Amit Kapila.