Date: Sun, 4 Apr 2021 16:05:14 -0400
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: yuzuko <yuzukohosoya@gmail.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>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
	Greg Stark <stark@mit.edu>
Subject: Re: Autovacuum on partitioned table (autoanalyze)
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On 2021-Apr-04, Tomas Vondra wrote:

> 1) I still don't understand why inheritance and declarative partitioning
> are treated differently. Seems unnecessary nad surprising, but maybe
> there's a good reason?

I suppose the rationale is that for inheritance we have always done it
that way -- similar things have been done that way for inheritance
historically, to avoid messing with long-standing behavior.  We have
done that in a bunch of places -- DDL behavior, FKs, etc.  Maybe in this
case it's not justified.  It *will* change behavior, in the sense that
we are going to capture stats that have never been captured before.
That might or might not affect query plans for designs using regular
inheritance.  But it seems reasonable to think that those changes will
be for the good; and if it does break plans for some people and they
want to revert to the original behavior, they can just set
autovacuum_enabled to off for the parent tables.

So, I agree that we should enable this new feature for inheritance
parents too.


I can't comment on the other issues.  I hope to give this a closer look
tomorrow my time; with luck Hosoya-san will have commented by then.


-- 
Álvaro Herrera                            39°49'30"S 73°17'W
"La rebeldía es la virtud original del hombre" (Arthur Schopenhauer)