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From: Robert Treat <rob@xzilla.net>
Date: Sat, 16 Aug 2025 09:41:57 -0400
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Subject: Re: Adding REPACK [concurrently]
To: Antonin Houska <ah@cybertec.at>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>,
	Pg Hackers <pgsql-hackers@lists.postgresql.org>
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On Tue, Aug 5, 2025 at 4:59=E2=80=AFAM Antonin Houska <ah@cybertec.at> wrot=
e:
>
> Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
>
> > I made a few changes from Antonin's original at [2].  First, I modified
> > the grammar to support "REPACK [tab] USING INDEX" without specifying th=
e
> > index name.  With this change, all possibilities of the old commands ar=
e
> > covered,
>
> ...
>
> > Here's a list of existing commands, and how to write them in the curren=
t
> > patch's proposal for REPACK:
> >
> > -- re-clusters all tables that have a clustered index set
> > CLUSTER                     -> REPACK USING INDEX
> >
> > -- clusters the given table using the given index
> > CLUSTER tab USING idx       -> REPACK tab USING INDEX idx
> >
> > -- clusters this table using a clustered index; error if no index clust=
ered
> > CLUSTER tab                 -> REPACK tab USING INDEX
> >

In the v18 patch, the docs say that repack doesn't remember the index,
but it seems we are still calling mark_index_clustered, so I think the
above is true but we need to update the docs(?).

> > -- vacuum-full all tables
> > VACUUM FULL                 -> REPACK
> >
> > -- vacuum-full the specified table
> > VACUUM FULL tab             -> REPACK tab
> >
>
> Now that we want to cover the CLUSTER/VACUUM FULL completely, I've checke=
d the
> options of VACUUM FULL. I found two items not supported by REPACK (but al=
so
> not supported by by CLUSTER): ANALYZE and SKIP_DATABASE_STATS. Maybe just
> let's mention that in the user documentation of REPACK?
>

I would note that both pg_repack and pg_squeeze analyze by default,
and running "vacuum full analyze" is the recommended behavior, so not
having analyze included is a step backwards.

> (Besides that, VACUUM FULL accepts TRUNCATE and INDEX_CLEANUP options, bu=
t I
> think these have no effect.)
>

Yeah, these seem safe to ignore.

Robert Treat
https://xzilla.net