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Date: Tue, 31 May 2011 20:55:38 -0400
Message-ID: <BANLkTimRjbzjqA13MLtjLf1XCini_UAAQw@mail.gmail.com>
Subject: Re: [PERFORM] Hash Anti Join performance degradation
From: Robert Haas <robertmhaas@gmail.com>
To: =?ISO-8859-1?Q?C=E9dric_Villemain?= <cedric.villemain.debian@gmail.com>
Cc: panam <panam@gmx.net>,
	PostgreSQL-development <pgsql-hackers@postgresql.org>
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On Tue, May 31, 2011 at 8:43 PM, C=E9dric Villemain
<cedric.villemain.debian@gmail.com> wrote:
> Yes, while here I noticed that the query was long to be killed.
> I added a CHECK_FOR_INTERRUPT() in the for(;;) loop in nodeHashjoin.c.
> It fixes the delay when trying to kill but I don't know about
> performance impact this can have in this place of the code.

Well, seems easy enough to find out: just test the query with and
without your patch (and without casserts).  If there's no measurable
difference on this query, there probably won't be one anywhere.

--=20
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company