Horton

Re: Poor memory context performance in large hash joins

Thomas Munro <thomas.munro@enterprisedb.com>

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From: Thomas Munro <thomas.munro@enterprisedb.com>
To: Andres Freund <andres@anarazel.de>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Tomas Vondra <tv@fuzzy.cz>, Jeff Janes <jeff.janes@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-02-24T07:00:27Z
Lists: pgsql-hackers

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On Fri, Feb 24, 2017 at 12:17 PM, Andres Freund <andres@anarazel.de> wrote:
> Jeff, do you have a handy demonstrator?

If you want to hit ExecHashIncreaseNumBatches a bunch of times, see
the "ugly" example in the attached.

-- 
Thomas Munro
http://www.enterprisedb.com

Commits

  1. Use doubly-linked block lists in aset.c to reduce large-chunk overhead.