Re: Adding REPACK [concurrently]

Antonin Houska <ah@cybertec.at>

From: Antonin Houska <ah@cybertec.at>

To: jian he <jian.universality@gmail.com>

Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Pg Hackers <pgsql-hackers@lists.postgresql.org>, Mihail Nikalayeu <mihailnikalayeu@gmail.com>, Robert Treat <rob@xzilla.net>

Date: 2025-12-04T13:36:12Z

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 →

Improve REPACK (CONCURRENTLY) error messages some more
- 378dffaf8c80 19 (unreleased) landed
Add CONCURRENTLY option to REPACK
- 28d534e2ae0a 19 (unreleased) landed
Make index_concurrently_create_copy more general
- 33bf7318f94c 19 (unreleased) landed
Document the 'command' column of pg_stat_progress_repack
- a630ac5c2016 19 (unreleased) landed
Introduce the REPACK command
- ac58465e0618 19 (unreleased) landed
Split vacuumdb to create vacuuming.c/h
- c4067383cb2c 19 (unreleased) landed
Revert changes to CONCURRENTLY that "sped up" Xmin advance
- 042b584c7f7d 14.4 cited

jian he <jian.universality@gmail.com> wrote:

>     if (params.options & CLUOPT_ANALYZE)
>         ereport(ERROR,
>                 errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
>                 errmsg("cannot %s multiple tables", "REPACK (ANALYZE)"));
> for this error case, adding a simple test case would be better?

More options should probably be tested, currently we have only very basic
regression test for pg_repackdb. TBD

> + /* Do an analyze, if requested */
> + if (params->options & CLUOPT_ANALYZE)
> + {
> + VacuumParams vac_params = {0};
> +
> + vac_params.options |= VACOPT_ANALYZE;
> + if (params->options & CLUOPT_VERBOSE)
> + vac_params.options |= VACOPT_VERBOSE;
> + analyze_rel(RelationGetRelid(rel), NULL, vac_params,
> + stmt->relation->va_cols, true, NULL);
> + }
> 
> Looking at the comments in struct VacuumParams, some fields have nonzero default
> values — for example, log_vacuum_min_duration.
> Do we need to explicitly set these fields to their default values?
> (see ExecVacuum)

Perhaps, TBD.

> repack.sgml can also add a
> <refsect1> <title>See Also</title>
> similar to analyze.sgml, vacuum.sgml

ok, added this in v26 (to be posted today):

 <refsect1>
  <title>See Also</title>

  <simplelist type="inline">
   <member><xref linkend="app-pgrepackdb"/></member>
   <member><xref linkend="repack-progress-reporting"/></member>
  </simplelist>
 </refsect1>

(Not added reference to VACUUM FULL and CLUSTER intentionally: whoever uses
REPACK should not need them.

> doc/src/sgml/ref/repack.sgml
> synopsis section missing syntax:
> REPACK USING INDEX

ok, added in v26.

> I am wondering, can we also support
> REPACK opt_utility_option_list USING INDEX

I agree, added that in v26 (Hopefully I haven't broken anything, the syntax is
not trival anymore.)

> MATERIALIZED VIEW:
> create materialized view a_________ as select * from t2;
> 
> repack (verbose);
> INFO:  repacking "public.a_________" in physical order
> INFO:  "public.a_________": found 0 removable, 10 nonremovable row
> versions in 1 pages
> DETAIL:  0 dead row versions cannot be removed yet.
> CPU: user: 0.00 s, system: 0.00 s, elapsed: 0.00 s.
> 
> cluster (verbose);
> won't touch materialized view a_________
> 
> but materialized views don't have bloat, nothing can be removed.
> So here we are waste cycles to repack materialized view?

Answered in https://www.postgresql.org/message-id/3436011762001613%40a7af8471-b1b8-48c2-9ff7-631187067407

-- 
Antonin Houska
Web: https://www.cybertec-postgresql.com