Date: Fri, 26 Jun 2020 00:02:10 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Andres Freund <andres@anarazel.de>,
	David Rowley <dgrowleyml@gmail.com>, Jeff Davis <pgsql@j-davis.com>,
	Justin Pryzby <pryzby@telsasoft.com>,
	Melanie Plageman <melanieplageman@gmail.com>,
	"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Subject: Re: Default setting for enable_hashagg_disk
Message-ID: <20200626040210.GA13963@momjian.us>
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 <CAApHDvrcfOOjRmO5EZk_a_GKd-RUGG+2FTM=Sr4jZUbHaBJqjA@mail.gmail.com>
 <20200624171203.GB17842@momjian.us>
 <20200624191900.t4sbfk236gndwoa3@alap3.anarazel.de>
 <20200624231810.GB13627@momjian.us>
 <20200624233837.GA21436@momjian.us>
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On Fri, Jun 26, 2020 at 01:53:57AM +0200, Tomas Vondra wrote:
> I'm not saying it's not beneficial to use different limits for different
> nodes. Some nodes are less sensitive to the size (e.g. sorting often
> gets faster with smaller work_mem). But I think we should instead have a
> per-session limit, and the planner should "distribute" the memory to
> different nodes. It's a hard problem, of course.

Yeah, I am actually confused why we haven't developed a global memory
allocation strategy and continue to use per-session work_mem.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

  The usefulness of a cup is in its emptiness, Bruce Lee