Date: Wed, 12 May 2021 17:30:26 +0800
From: Julien Rouhaud <rjuju123@gmail.com>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: Kyotaro Horiguchi <horikyota.ntt@gmail.com>,
	Magnus Hagander <magnus@hagander.net>,
	Fujii Masao <masao.fujii@oss.nttdata.com>,
	Michael Paquier <michael@paquier.xyz>,
	Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>,
	Alvaro Herrera <alvherre@alvh.no-ip.org>,
	Stephen Frost <sfrost@snowman.net>,
	Bruce Momjian <bruce@momjian.us>, Christoph Berg <myon@debian.org>,
	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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On Wed, May 12, 2021 at 10:57:25AM +0200, Pavel Stehule wrote:
> 
> My second proposal can work for your example too. pg_stat_statements have
> to require any active queryid computing. And when it is not available, then
> the exception should be raised.
> 
> The custom queryid can return null, and still the queryid will be computed.
> Maybe the warning can be enough. Just, if somebody use pg_stat_statements
> function, then enforce the check if queryid is computed (compute_query_id
> is true || some hook is not null), and if not then raise a warning.

Ah I'm sorry I misunderstood your proposal.  Yes, definitely adding a warning
or an error when executing pg_stat_statements() SRF would help, that's a great
idea!

I'll wait a bit in case someone has any objection, and if not send an updated
patch!