From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: David G. Johnston <david.g.johnston@gmail.com>
Cc: FabrÃzio Mello <fabriziomello@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Add important info about ANALYZE after create Functional Index
Date: Wed, 28 Oct 2020 20:13:48 +0100
Message-ID: <20201028191348.u4jwtawz4c533xge@development> (raw)
In-Reply-To: <1442677.1603911939@sss.pgh.pa.us>
References: <CAFcNs+qpFPmiHd1oTXvcPdvAHicJDA9qBUSujgAhUMJyUMb+SA@mail.gmail.com>
<CAKFQuwb9GFe4oM3k9bsn7GOk5_jfow-9SpWocAG4xAYVp9nLjg@mail.gmail.com>
<20201028185538.fzux2lhim472h46o@development>
<1442677.1603911939@sss.pgh.pa.us>
On Wed, Oct 28, 2020 at 03:05:39PM -0400, Tom Lane wrote:
>Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
>> On Mon, Oct 26, 2020 at 03:46:10PM -0700, David G. Johnston wrote:
>>> It would seem preferable to call the lack of auto-analyzing after these
>>> operations a bug and back-patch a fix that injects an analyze side-effect
>>> just before their completion. It doesn't have to be smart either,
>>> analyzing things even if the created (or newly validated) index doesn't
>>> have statistics of its own isn't a problem in my book.
>
>> I agree the lack of stats may be quite annoying and cause issues, but my
>> guess is the chances of backpatching such change are about 0.000001%. We
>> have a usable 'workaround' for this - manual analyze.
>
>This doesn't seem clearly different from any other situation where
>auto-analyze doesn't react fast enough to suit you. I would not
>call it a bug, at least not without a wholesale redefinition of
>how auto-analyze is supposed to work. As a close analogy, we
>don't make any effort to force an immediate auto-analyze after
>CREATE STATISTICS.
>
True.
>I don't see anything in the CREATE STATISTICS man page pointing
>that out, either. But there's probably room for "Notes" entries
>about it in both places.
>
I agree. I'll add it to my TODO list for the next CF.
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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Cc: tomas.vondra@2ndquadrant.com, tgl@sss.pgh.pa.us, david.g.johnston@gmail.com, fabriziomello@gmail.com, pgsql-hackers@lists.postgresql.org
Subject: Re: Add important info about ANALYZE after create Functional Index
In-Reply-To: <20201028191348.u4jwtawz4c533xge@development>
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