Horton

Re: Adding REPACK [concurrently]

Mikhail Nikalayeu <mihailnikalayeu@gmail.com>

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From: Mihail Nikalayeu <mihailnikalayeu@gmail.com>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Pg Hackers <pgsql-hackers@lists.postgresql.org>, Antonin Houska <ah@cybertec.at>, Robert Treat <rob@xzilla.net>
Date: 2025-11-01T18:16:00Z
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. Improve REPACK (CONCURRENTLY) error messages some more

  2. Add CONCURRENTLY option to REPACK

  3. Make index_concurrently_create_copy more general

  4. Document the 'command' column of pg_stat_progress_repack

  5. Introduce the REPACK command

  6. Split vacuumdb to create vacuuming.c/h

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

Hello!

On Fri, Oct 31, 2025 at 12:17 AM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> Here's a new installment of this series, v25, including the CONCURRENTLY
> part, which required some conflict fixes on top of the much-changed
> v24-0001 patch.

 > * cluster.c
 > *      CLUSTER a table on an index.  This is now also used for VACUUM FULL.

 Should we add something about repack here?

 > ii_ExclusinOps
 typo here.

 >  * index is inserted into catalogs and needs to be built later on.
 Now it is only in case concurrently == true

>   * Build the index information for the new index.  Note that rebuild of
>   * indexes with exclusion constraints is not supported, hence there is no
>   * need to fill all the ii_Exclusion* fields.

Now the function supports its in !concurrently mode. Should we fill
ii_Exclusion? Also, it says

> If !concurrently, ii_ExclusinOps is currently not needed.

But it is not clear - why not?

>   newInfo = makeIndexInfo(oldInfo->ii_NumIndexAttrs,
>                           oldInfo->ii_NumIndexKeyAttrs,
>                           oldInfo->ii_Am,
>                           indexExprs,
>                           indexPreds,
>                           oldInfo->ii_Unique,
>                           oldInfo->ii_NullsNotDistinct,
>                           false,  /* not ready for inserts */
>                           true,
>                           indexRelation->rd_indam->amsummarizing,
>                           oldInfo->ii_WithoutOverlaps);

Is it ok we pass isready == false if !concurrent?
Also, we pass concurrent == true even if concurrently == false - feels
strange and probably wrong.


> This difference does has no impact on XidInMVCCSnapshot().
Should it be "This difference has no impact"?

> * pgoutput_cluster.c
> *       src/backend/replication/pgoutput_cluster/pgoutput_cluster.c
 it is pgoutput_trepack.c :)

Best regards,
Mikhail.