From: Bruce Momjian <bruce@momjian.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>
Cc: Julien Rouhaud <rjuju123@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: torikoshia <torikoshia@oss.nttdata.com>
Cc: Atsushi Torikoshi <atorik@gmail.com>
Cc: Tatsuro Yamada <tatsuro.yamada.tf@nttcom.co.jp>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: Evgeny Efimkin <efimkin@yandex-team.ru>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Feature improvement: can we add queryId for pg_catalog.pg_stat_activity view?
Date: Mon, 12 Oct 2020 16:53:40 -0400
Message-ID: <20201012205340.GD24889@momjian.us> (raw)
In-Reply-To: <3250173.1602533250@sss.pgh.pa.us>
References: <20201006053458.GA429@paquier.xyz>
<20201006132229.GB3686@momjian.us>
<20201007014249.GB2256@paquier.xyz>
<20201007015346.GF12277@momjian.us>
<CAOBaU_bt3-CwkAQLu7kUp-Yy7dyjhTntNG7Q30CssJHjaPYKEQ@mail.gmail.com>
<20201012141445.GA24889@momjian.us>
<CA+TgmoaK55MiAU1wxizK05ZkxK8KKj83P2WxWCTQ7LLe9P6RCA@mail.gmail.com>
<3199563.1602527175@sss.pgh.pa.us>
<20201012195443.GC24889@momjian.us>
<3250173.1602533250@sss.pgh.pa.us>
On Mon, Oct 12, 2020 at 04:07:30PM -0400, Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> > On Mon, Oct 12, 2020 at 02:26:15PM -0400, Tom Lane wrote:
> >> Yeah, I agree --- a version number is the wrong way to think about this.
>
> > The version number was to invalidate _all_ query hashes if the
> > algorithm is slightly modified, rather than invalidating just some of
> > them, which could lead to confusion.
>
> Color me skeptical as to the use-case for that. From users' standpoints,
> the hash is mainly going to change when we change the set of parse node
> fields that get hashed. Which is going to happen at every major release
> and no (or at least epsilon) minor releases. So I do not see a point in
> tracking an algorithm version number as such. Seems like make-work.
OK, I came up with the hash idea only to address one of your concerns
about mismatched hashes for algorithm improvements/changes. Seems we
might as well just document that cross-version hashes are different.
--
Bruce Momjian <bruce@momjian.us> https://momjian.us
EnterpriseDB https://enterprisedb.com
The usefulness of a cup is in its emptiness, Bruce Lee
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To: pgsql-hackers@postgresql.org
Cc: bruce@momjian.us, tgl@sss.pgh.pa.us, robertmhaas@gmail.com, rjuju123@gmail.com, michael@paquier.xyz, alvherre@alvh.no-ip.org, torikoshia@oss.nttdata.com, atorik@gmail.com, tatsuro.yamada.tf@nttcom.co.jp, tomas.vondra@2ndquadrant.com, efimkin@yandex-team.ru, pgsql-hackers@lists.postgresql.org
Subject: Re: Feature improvement: can we add queryId for pg_catalog.pg_stat_activity view?
In-Reply-To: <20201012205340.GD24889@momjian.us>
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