Horton

Re: Logical Replication of sequences

vignesh C <vignesh21@gmail.com>

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From: vignesh C <vignesh21@gmail.com>
To: shveta malik <shveta.malik@gmail.com>
Cc: Shlok Kyal <shlok.kyal.oss@gmail.com>, Chao Li <li.evan.chao@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, Nisha Moond <nisha.moond412@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Peter Smith <smithpb2250@gmail.com>, Peter Eisentraut <peter@eisentraut.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Euler Taveira <euler@eulerto.com>, Michael Paquier <michael@paquier.xyz>, "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, "Jonathan S. Katz" <jkatz@postgresql.org>
Date: 2025-09-23T13:09:27Z
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

Attachments

On Mon, 22 Sept 2025 at 12:03, shveta malik <shveta.malik@gmail.com> wrote:
>
> On Thu, Sep 18, 2025 at 4:07 PM vignesh C <vignesh21@gmail.com> wrote:
> >
> > Thanks for the comments, these are handled in the attached patch.
> >
>
> Please find a few comments:
>
>
> patch005:
> 1)
> GetSubscriptionRelations:
> + /* Skip sequences if they were not requested */
> + if (!get_sequences && (relkind == RELKIND_SEQUENCE))
> + continue;
> +
> + /* Skip tables if they were not requested */
> + if (!get_tables && (relkind != RELKIND_SEQUENCE))
> + continue;
>
> The use of negated conditions makes the logic harder to follow,
> especially in the second if block.
>
> Can we write it as:
>    bool is_sequence = (relkind == RELKIND_SEQUENCE);
>
>    /* Skip if the relation type is not requested */
>    if ((get_tables && is_sequence) ||
>        (get_sequences && !is_sequence))
>        continue;
>
> Or at-least:
> /* Skip sequences if they were not requested */
> if (get_tables && (relkind == RELKIND_SEQUENCE))
>   continue;
>
> /* Skip tables if they were not requested */
> if (get_sequences && (relkind != RELKIND_SEQUENCE))
>   continue;

I felt this would not work. Say we want both sequences and tables,
won't it skip the sequence this way from:
if (get_tables && (relkind == RELKIND_SEQUENCE))
  continue;

Rest of the comments were fixed, also the comment from [1] is fixed in
the attached patch.
[1] - https://www.postgresql.org/message-id/CAJpy0uAdD9XtZCE34BJhbvncMgfmMuTS0ZXLP1P=g+wpRC8vqQ@mail.gmail.com

Regards,
Vignesh