Re: Logical Replication of sequences

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>
To: shveta malik <shveta.malik@gmail.com>
Cc: vignesh C <vignesh21@gmail.com>, 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>, 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: 2025-10-07T06:39:01Z
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 Tue, Oct 7, 2025 at 10:53 AM shveta malik <shveta.malik@gmail.com> wrote:
>
> 2)
> postgres=# create publication pub1 for all sequences WITH(publish='insert');
> ERROR:  publication parameters are not supported for publications
> defined as FOR ALL SEQUENCES
>
> postgres=# alter publication pub1 add table tab1;
> ERROR:  Tables or sequences cannot be added to or dropped from
> publication defined FOR ALL TABLES, ALL SEQUENCES, or both
>
> a) First msg has 'as', while second does not. Shall we make both the
> same? I think we can get rid of 'as'.
> b) Shouldn't the error msg start with lower case (second one)?
>

The (b) is related to following change:

+  if (tables && (pubform->puballtables || pubform->puballsequences))
    ereport(ERROR,
-        (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-         errmsg("publication \"%s\" is defined as FOR ALL TABLES",
-            NameStr(pubform->pubname)),
-         errdetail("Tables cannot be added to or dropped from FOR ALL
TABLES publications.")));
+        errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+        errmsg("Tables or sequences cannot be added to or dropped
from publication defined FOR ALL TABLES, ALL SEQUENCES, or both"));
}

I see a bigger problem where we made errdetail as errmsg. Here, we are
trying to combine the message FOR ALL TABLES and FOR ALL SEQUENCES
which caused this change/confusion. It is better to keep them separate
to avoid confusion. The similar problem exists for following message:
- if (schemaidlist && pubform->puballtables)
+ if (schemaidlist && (pubform->puballtables || pubform->puballsequences))
  ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("publication \"%s\" is defined as FOR ALL TABLES",
- NameStr(pubform->pubname)),
- errdetail("Schemas cannot be added to or dropped from FOR ALL TABLES
publications.")));
+ errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("Schemas cannot be added to or dropped from publication
defined FOR ALL TABLES, ALL SEQUENCES, or both"));

If we fix both of these then we don't need to do anything for point (a).

Few other comments:
=================
1. Is there a reason not to change just the footers part in
describeOneTableDetails()?
2. I think we can move create_publication.sgml and
pg_publication_sequences related changes to 0001 from doc patch.
3. Atop is_publishable_class(), we mention it has all the checks as
check_publication_add_relation but the sequence check is different. Is
it because check_publication_add_relation() is not called FOR ALL
SEQUENCES? If so, I have modified a few comments in the attached
related to that.
4.
@@ -878,13 +885,35 @@ CreatePublication(ParseState *pstate,
CreatePublicationStmt *stmt)
    &publish_via_partition_root_given,
    &publish_via_partition_root,
    &publish_generated_columns_given,
-   &publish_generated_columns);
+   &publish_generated_columns,
+   def_pub_action);
+
+ if (stmt->for_all_sequences &&
+ (publish_given || publish_via_partition_root_given ||
+ publish_generated_columns_given))
+ {
+ /*
+ * WITH clause parameters are not applicable when creating a FOR ALL
+ * SEQUENCES publication. If the publication includes tables as well,
+ * issue a notice.
+ */
+ if (!stmt->for_all_tables)
+ ereport(ERROR,
+ errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("publication parameters are not supported for publications
defined as FOR ALL SEQUENCES"));
+
+ ereport(NOTICE,
+ errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("publication parameters are not applicable to sequence
synchronization and will be ignored"));
+ }

This change looks a bit ad hoc to me. I think it would be better to
handle this inside parse_publication_options(). The function can take
the third parameter as for_all_sequences and then use that to give
error when any options are present.

-- 
With Regards,
Amit Kapila.