Date: Mon, 16 Aug 2021 13:00:00 -0400
From: =?utf-8?Q?=C3=81lvaro?= Herrera <alvherre@alvh.no-ip.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andres Freund <andres@anarazel.de>,
	Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>,
	yuzuko <yuzukohosoya@gmail.com>,
	Tomas Vondra <tomas.vondra@enterprisedb.com>,
	David Steele <david@pgmasters.net>,
	Kyotaro Horiguchi <horikyota.ntt@gmail.com>,
	Justin Pryzby <pryzby@telsasoft.com>,
	Daniel Gustafsson <daniel@yesql.se>,
	Amit Langote <amitlangote09@gmail.com>,
	Masahiko Sawada <masahiko.sawada@2ndquadrant.com>,
	Laurenz Albe <laurenz.albe@cybertec.at>,
	"pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>,
	Greg Stark <stark@mit.edu>
Subject: Re: Autovacuum on partitioned table (autoanalyze)
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On 2021-Aug-16, Tom Lane wrote:

> =?utf-8?Q?=C3=81lvaro?= Herrera <alvherre@alvh.no-ip.org> writes:
> > Here's the reversal patch for the 14 branch.  (It applies cleanly to
> > master, but the unused member of PgStat_StatTabEntry needs to be
> > removed and catversion bumped).
> 
> I don't follow the connection to catversion?

Sorry, I misspoke -- I mean PGSTAT_FORMAT_FILE_ID.  I shouldn't just
change it, since if I do then the file is reported as corrupted and all
counters are lost.  So in the posted patch I did as you suggest:

> I agree that we probably don't want to change PgStat_StatTabEntry in
> v14 at this point.  But it'd be a good idea to attach a comment to
> the entry saying it's unused but left there for ABI reasons.

It's only in branch master that I'd change the pgstat format version and
remove the field.  This is what I meant with the patch being for v14 and
a tweak needed for this in master.

A catversion bump would be required to change the definition of
pg_stat_user_tables, which the patch being reverted originally changed
to include relkind 'p'.  A straight revert would remove that, but in my
reversal patch I chose to keep it in place.

-- 
Álvaro Herrera           39°49'30"S 73°17'W  —  https://www.EnterpriseDB.com/
"Pensar que el espectro que vemos es ilusorio no lo despoja de espanto,
sólo le suma el nuevo terror de la locura" (Perelandra, C.S. Lewis)