From: Tom Lane <tgl@sss.pgh.pa.us>
To: Sami Imseih <samimseih@gmail.com>
cc: Michael Paquier <michael@paquier.xyz>, Christoph Berg <myon@debian.org>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
        ma lz <ma100@hotmail.com>
Subject: Re: query_id: jumble names of temp tables for better pg_stat_statement UX
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Comments: In-reply-to Sami Imseih <samimseih@gmail.com>
	message dated "Mon, 24 Mar 2025 21:38:35 -0500"
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Date: Mon, 24 Mar 2025 22:56:30 -0400
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Sami Imseih <samimseih@gmail.com> writes:
> I agree that some may want stats to merge for the same tables,
> and others may not. I will suggest this with some hesitation, but why not
> make this behavior configurable via a GUC?
> We recently introduced query_id_squash_values for controlling
> the merge of an IN list, maybe this is another queryId behavior we should
> provide a configuration for?

I don't like that GUC and I would not like this one either.  We
learned years ago that GUCs that change query semantics are a bad
idea, but apparently now we have hackers who need to relearn that
lesson the hard way.  (Admittedly, this isn't quite *query* semantics,
which perhaps lessens the blast radius.  But I think we're still going
to regret query_id_squash_values.)

			regards, tom lane