Horton

Re: Logical Replication of sequences

Peter Smith <smithpb2250@gmail.com>

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From: Peter Smith <smithpb2250@gmail.com>
To: vignesh C <vignesh21@gmail.com>
Cc: 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: 2024-07-10T08:16:03Z
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

Here are a few comments for patch v20240705-0003.

(This is a WIP. I have only looked at the docs so far.)

======
doc/src/sgml/config.sgml

nitpick - max_logical_replication_workers: /and sequence
synchornization worker/and a sequence synchornization worker/

======
doc/src/sgml/logical-replication.sgml

nitpick - max_logical_replication_workers: re-order list of workers to
be consistent with other docs 1-apply,2-parallel,3-tablesync,4-seqsync

======
doc/src/sgml/ref/alter_subscription.sgml

1.
IIUC the existing "REFRESH PUBLICATION" command will fetch and sync
all new sequences, etc., and/or remove old ones no longer in the
publication. But current docs do not say anything at all about
sequences here. It should say something about sequence behaviour.

~~~

2.
For the existing "REFRESH PUBLICATION" there is a sub-option
"copy_data=true/false". Won't this need some explanation about how it
behaves for sequences? Or will there be another option
"copy_sequences=true/false".

~~~

3.
IIUC the main difference between REFRESH PUBLICATION and REFRESH
PUBLICATION SEQUENCES is that the 2nd command will try synchronize
with all the *existing* sequences to bring them to the same point as
on the publisher, but otherwise, they are the same command. If that is
correct understanding I don't think that distinction is made very
clear in the current docs.

~~~

nitpick - the synopsis is misplaced. It should not be between ENABLE
and DISABLE. I moved it. Also, it should say "REFRESH PUBLICATION
SEQUENCES" because that is how the new syntax is defined in gram.y

nitpick - REFRESH SEQUENCES. Renamed to "REFRESH PUBLICATION
SEQUENCES". And, shouldn't "from the publisher" say "with the
publisher"?

nitpick - changed the varlistentry "id".

======
99.
Please also see the attached diffs patch which implements any nitpicks
mentioned above.

======
Kind Regards,
Peter Smith.
Fujitsu Australia