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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Shulgin, Oleksandr <oleksandr.shulgin@zalando.de>
Cc: Simon Riggs <simon@2ndquadrant.com>
Cc: Robert Haas <robertmhaas@gmail.com>
Cc: Pavel Stehule <pavel.stehule@gmail.com>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: On-demand running query plans using auto_explain and signals
Date: Thu, 15 Oct 2015 09:42:47 -0400
Message-ID: <32603.1444916567@sss.pgh.pa.us> (raw)
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"Shulgin, Oleksandr" <oleksandr.shulgin@zalando.de> writes:
> I was thinking about this and what seems to be the biggest problem is when
> to actually turn the feature on.  It seems unlikely that someone will want
> to enable it unconditionally.  Enabling per-backend also doesn't seem to be
> a good approach because you don't know if the next query you'd like to look
> at is going to run in this exact backend.

Check.

> What might be actually usable is poking pg_stat_statements for queryid to
> decide if we need to do explain (and possibly analyze).

Hm, interesting thought.

> Does this make sense to you?  Does this make a good argument for merging
> pg_stat_statements and auto_explain into core?

I'd say more that it's a good argument for moving this feature out to
one of those extensions, or perhaps building a third extension that
depends on both of those.  TBH, none of this stuff smells to me like
something that ought to be in core.

			regards, tom lane


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  Cc: tgl@sss.pgh.pa.us, oleksandr.shulgin@zalando.de, simon@2ndquadrant.com, robertmhaas@gmail.com, pavel.stehule@gmail.com, tomas.vondra@2ndquadrant.com
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