From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Geoghegan <pg@bowt.ie>
cc: Jeff Davis <pgsql@j-davis.com>, Stephen Frost <sfrost@snowman.net>,
        Alvaro Herrera <alvherre@2ndquadrant.com>,
        Andres Freund <andres@anarazel.de>, Bruce Momjian <bruce@momjian.us>,
        Robert Haas <robertmhaas@gmail.com>,
        David Rowley <dgrowleyml@gmail.com>,
        Justin Pryzby <pryzby@telsasoft.com>,
        Melanie Plageman <melanieplageman@gmail.com>,
        Tomas Vondra <tomas.vondra@2ndquadrant.com>,
        "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Subject: Re: Default setting for enable_hashagg_disk
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Comments: In-reply-to Peter Geoghegan <pg@bowt.ie>
	message dated "Fri, 10 Jul 2020 14:24:21 -0700"
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Date: Fri, 10 Jul 2020 17:30:41 -0400
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Peter Geoghegan <pg@bowt.ie> writes:
> It now seems likely that the hash_mem/hash_mem_multiplier proposal has
> the support it needs to get into Postgres 13. Assuming that the
> proposal doesn't lose momentum, then it's about time to return to the
> original question you posed at the start of the thread:

> What should we do with the hashagg_avoid_disk_plan GUC (formerly known
> as the enable_hashagg_disk GUC), if anything?

> I myself think that there is a case to be made for removing it
> entirely.

+0.5 or so for removing it.  It seems too confusing and dubiously
useful.

			regards, tom lane