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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Julien Rouhaud <rjuju123@gmail.com>
cc: Bruce Momjian <bruce@momjian.us>, Stephen Frost <sfrost@snowman.net>,
        Christoph Berg <myon@debian.org>,
        Pavel Stehule <pavel.stehule@gmail.com>,
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        Peter Eisentraut <peter.eisentraut@enterprisedb.com>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: compute_query_id and pg_stat_statements
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Comments: In-reply-to Julien Rouhaud <rjuju123@gmail.com>
	message dated "Fri, 14 May 2021 09:36:19 +0800"
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Date: Thu, 13 May 2021 21:47:02 -0400
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Julien Rouhaud <rjuju123@gmail.com> writes:
> On Fri, May 14, 2021 at 3:12 AM Bruce Momjian <bruce@momjian.us> wrote:
>> I was surprised it was ~2%.

> Just to be clear, the 2% was a worst case scenario, ie. a very fast
> read-only query on small data returning a single row.  As soon as you
> get something more realistic / expensive the overhead goes away.

Of course, for plenty of people that IS the realistic scenario that
they care about max performance for.

			regards, tom lane