pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  

help / color / mirror / Atom feed
From: Ross J. Reedstrom <reedstrm@rice.edu>
To: pgsql-hackers@postgresql.org
Subject: Re: [PERFORM] Hash Anti Join performance degradation
Date: Wed, 1 Jun 2011 16:53:15 -0500
Message-ID: <20110601215315.GC14215@rice.edu> (raw)
In-Reply-To: <BANLkTimXuMGGv_vPQrQjR17K3QomP8NnQw@mail.gmail.com>
References: <BANLkTikDKUF53_MhP-T9y9NM7a8z40djXA@mail.gmail.com>
	<BANLkTinbb35QT_57EozGOnszBWuarBgW1g@mail.gmail.com>
	<7913.1306900062@sss.pgh.pa.us>
	<BANLkTim-DqDC2AbVJ_1t-XAS4NYq2tQYZg@mail.gmail.com>
	<24247.1306959956@sss.pgh.pa.us>
	<BANLkTim=Tp55eM1Ch6VMtkHT5Tr=Xvnq5g@mail.gmail.com>
	<24461.1306960516@sss.pgh.pa.us>
	<BANLkTi=6pGhGOUddirQmEqavJ3_T-y4xFA@mail.gmail.com>
	<24707.1306961256@sss.pgh.pa.us>
	<BANLkTimXuMGGv_vPQrQjR17K3QomP8NnQw@mail.gmail.com>

On Wed, Jun 01, 2011 at 04:58:36PM -0400, Robert Haas wrote:
> On Wed, Jun 1, 2011 at 4:47 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> > Robert Haas <robertmhaas@gmail.com> writes:
> >> I guess the real issue here is that m1.id < m2.id has to be evaluated
> >> as a filter condition rather than a join qual.
> >
> > Well, if you can invent an optimized join technique that works for
> > inequalities, go for it ... but I think you should get at least a
> > PhD thesis out of that.
> 
> Sounds good, except that so far NOT getting a PhD seems like a much
> better financial prospect.  :-)

Yeah, last time I heard of some Uni being so impressed by independent
work that they just sort of handed out a Ph.D. it involved a Swiss
patent clerk ...

Ross
-- 
Ross Reedstrom, Ph.D.                                 reedstrm@rice.edu
Systems Engineer & Admin, Research Scientist        phone: 713-348-6166
Connexions                  http://cnx.org            fax: 713-348-3665
Rice University MS-375, Houston, TX 77005
GPG Key fingerprint = F023 82C8 9B0E 2CC6 0D8E  F888 D3AE 810E 88F0 BEDE



view thread (35+ messages)  latest in thread

Message-ID: <20110601215315.GC14215@rice.edu>
Permalink:  ../20110601215315.GC14215@rice.edu/
Also on:    postgresql.org/message-id/20110601215315.GC14215@rice.edu

 · 

reply
Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-performance@postgresql.org
  Cc: reedstrm@rice.edu, pgsql-hackers@postgresql.org
  Subject: Re: [PERFORM] Hash Anti Join performance degradation
  In-Reply-To: <20110601215315.GC14215@rice.edu>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox