Re: Adding REPACK [concurrently]

Mihail Nikalayeu <mihailnikalayeu@gmail.com>

From: Mihail Nikalayeu <mihailnikalayeu@gmail.com>
To: Antonin Houska <ah@cybertec.at>
Cc: Andres Freund <andres@anarazel.de>, Amit Kapila <amit.kapila16@gmail.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Srinath Reddy Sadipiralla <srinath2133@gmail.com>, Matthias van de Meent <boekewurm+postgres@gmail.com>, Pg Hackers <pgsql-hackers@lists.postgresql.org>, Robert Treat <rob@xzilla.net>
Date: 2026-04-15T15:54:12Z
Lists: pgsql-hackers
Hello!

On Wed, Apr 15, 2026 at 4:50 PM Antonin Houska <ah@cybertec.at> wrote:
> The approach proposed by Mihail [1] seems the least problematic to me, and
> something like that occurred to me when I thought about the problem the first
> time. However, when we wake up the other processes in order to run the
> deadlock detection, they should do that immediately. I've got no good idea
> about implementation at the moment, since latch can be set for unrelated
> reasons. (Besides that, I have some more questions about this patch, which I
> can post separately.)

It is already possible to "deadlock" ANOTHER backend while running the
deadlock check [0].
Supported in current infra, just not used at the moment (my POC used that also).

[0]: https://github.com/postgres/postgres/blob/master/src/backend/storage/lmgr/proc.c#L1870-L1873



Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Allow old WAL recycling during REPACK CONCURRENTLY

  2. Advance restart_lsn more eagerly in LogicalConfirmReceivedLocation

  3. Remove unnecessary signal handler change

  4. Improve REPACK (CONCURRENTLY) error messages some more

  5. Revert "Allow logical replication snapshots to be database-specific"

  6. Move REPACK (CONCURRENTLY) test out of stock regression tests

  7. REPACK: do not require REPLICATION or LOGIN

  8. Add missing initialization

  9. Simplify declaration of memcpy target

  10. Reserve replication slots specifically for REPACK

  11. doc: Add an example of REPACK (CONCURRENTLY)

  12. Allow logical replication snapshots to be database-specific

  13. Avoid different-size pointer-to-integer cast

  14. Fix valgrind failure

  15. Add CONCURRENTLY option to REPACK

  16. Rename cluster.c to repack.c (and corresponding .h)

  17. Allow index_create to suppress index_build progress reporting

  18. Make index_concurrently_create_copy more general

  19. Document the 'command' column of pg_stat_progress_repack

  20. Introduce the REPACK command

  21. Toggle logical decoding dynamically based on logical slot presence.

  22. Split vacuumdb to create vacuuming.c/h

  23. Remove ReorderBufferTupleBuf structure.

  24. Revert changes to CONCURRENTLY that "sped up" Xmin advance

  25. VACUUM: ignore indexing operations with CONCURRENTLY