Message-ID: <6886e8bffbccf14766ba66c08ca4bcc174c1c1d8.camel@j-davis.com>
Subject: Re: Statistics Import and Export
From: Jeff Davis <pgsql@j-davis.com>
To: Nathan Bossart <nathandbossart@gmail.com>, Hari Krishna Sunder
	 <hari.db.pg@gmail.com>
Cc: Corey Huinker <corey.huinker@gmail.com>, Robert Treat <rob@xzilla.net>,
 Robert Haas <robertmhaas@gmail.com>, Andres Freund <andres@anarazel.de>,
 Tom Lane <tgl@sss.pgh.pa.us>,  Michael Paquier <michael@paquier.xyz>, jian
 he <jian.universality@gmail.com>, Bruce Momjian <bruce@momjian.us>,
 Matthias van de Meent <boekewurm+postgres@gmail.com>, Magnus Hagander
 <magnus@hagander.net>, Stephen Frost <sfrost@snowman.net>,  Ashutosh Bapat
 <ashutosh.bapat.oss@gmail.com>, Peter Smith <smithpb2250@gmail.com>,
 PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
 alvherre@alvh.no-ip.org
Date: Wed, 21 May 2025 14:14:55 -0700
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On Wed, 2025-05-21 at 11:08 -0500, Nathan Bossart wrote:
> On Tue, May 20, 2025 at 10:32:39AM -0700, Hari Krishna Sunder wrote:
> > Ah ya, forgot that reltuples are not always accurate. This sounds
> > reasonable to me.
>=20
> Cool.=C2=A0 Here is what I have staged for commit, which I am planning to
> do
> shortly.

Originally, one of the reasons we added a version field during dump is
so that some future version could reinterpret stats in older dump files
during import.

This patch is using a newer version of pg_dump to interpret stats from
older versions during export. That might be fine, but it would be good
to understand where the line is between things we should reinterpret
during export vs things we should reinterpret during import.

Regards,
	Jeff Davis