Date: Thu, 25 Jun 2020 18:58:53 -0400
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Andres Freund <andres@anarazel.de>
Cc: Bruce Momjian <bruce@momjian.us>, Jeff Davis <pgsql@j-davis.com>,
	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
Message-ID: <20200625225853.GA11137@alvherre.pgsql>
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On 2020-Jun-25, Andres Freund wrote:

> >My point here is that maybe we don't need to offer a GUC to explicitly
> >turn spilling off; it seems sufficient to let users change work_mem so
> >that spilling will naturally not occur.  Why do we need more?
> 
> That's not really a useful escape hatch, because I'll often lead to
> other nodes using more memory.

Ah -- other nodes in the same query -- you're right, that's not good.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services