Re: Adding REPACK [concurrently]

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Antonin Houska <ah@cybertec.at>
Cc: Tomas Vondra <tomas@vondra.me>, Alvaro Herrera <alvherre@alvh.no-ip.org>, vignesh C <vignesh21@gmail.com>, Srinath Reddy Sadipiralla <srinath2133@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Mihail Nikalayeu <mihailnikalayeu@gmail.com>, Matthias van de Meent <boekewurm+postgres@gmail.com>, Pg Hackers <pgsql-hackers@lists.postgresql.org>, Robert Treat <rob@xzilla.net>
Date: 2026-04-08T16:47:33Z
Lists: pgsql-hackers
Antonin Houska <ah@cybertec.at> writes:
> Tomas Vondra <tomas@vondra.me> wrote:
>> while building on a rpi5 with a 32-bit system, I'm getting these warnings:
>> ...
>> I'm not sure if it's just the compiler (gcc 14.2) being pesky, or if
>> it's an actual issue. The repack tests seem to pass fine.

Several 32-bit BF animals are showing these too (so far: dodo,
grison, and turaco).

> We already introduced this definition above in the function to suppress this
> kind of warning

>     union
>     {
> 	    alignas(int32) varlena hdr;
> 	    char		data[sizeof(void *)];
>     }			chunk_header;

> The problem on a 32-bit system probably is that sizeof(void *) is 4. We need
> some other constant. Maybe (sizeof(varlena) + 1) ...

This seems unnecessarily Rube Goldberg-ish already.  Why not just

	uint64	chunk_header;

It will not hurt anything if the variable has more-than-required
alignment.  And it'd be better if it were the same size everywhere.

			regards, tom lane



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