Re: Poor memory context performance in large hash joins

From: Andres Freund <andres(at)anarazel(dot)de>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Poor memory context performance in large hash joins
Date: 2017-02-24 23:12:37
Message-ID: 20170224231237.rzhlpdgnkby266sc@alap3.anarazel.de
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On 2017-02-24 18:04:18 -0500, Tom Lane wrote:
> Concretely, something like the attached. This passes regression tests
> but I've not pushed on it any harder than that.

Heh, I'd just gotten something that didn't immediately crash anymore ;)

Running your patch against Jeff's test-case, verified before that I
could easily reproduce the O(N^2) cost.

- Andres

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