From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
cc: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>,
        PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: Add ALL_CANDIDATES option to EXPLAIN
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Comments: In-reply-to Robert Haas <robertmhaas@gmail.com>
	message dated "Fri, 26 Jul 2024 13:16:43 -0400"
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Date: Fri, 26 Jul 2024 13:40:12 -0400
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Robert Haas <robertmhaas@gmail.com> writes:
> I've thought about trying to figure out some way of identifying and
> printing out plans that are "interestingly different" from the chosen
> plan, with the costs they would have had, but I haven't been able to
> come up with a good algorithm.

I wonder how far you'd get by just printing the surviving paths
(that is, something like Anthonin's patch, but without lobotomizing
add_path).  The survivors would have to dominate the cheapest-total
path along one of the other metrics add_path considers, which
seems like a rough approximation of "interestingly different".

			regards, tom lane