Re: [PERFORM] Hash Anti Join performance degradation

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Robert Haas <robertmhaas(at)gmail(dot)com>
Cc: Cédric Villemain <cedric(dot)villemain(dot)debian(at)gmail(dot)com>, panam <panam(at)gmx(dot)net>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: [PERFORM] Hash Anti Join performance degradation
Date: 2011-06-01 20:47:36
Message-ID: 24707.1306961256@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers pgsql-performance

Robert Haas <robertmhaas(at)gmail(dot)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.

regards, tom lane

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Andrew Chernow 2011-06-01 20:48:55 Re: PQdeleteTuple function in libpq
Previous Message Robert Haas 2011-06-01 20:43:29 Re: [PERFORM] Hash Anti Join performance degradation

Browse pgsql-performance by date

  From Date Subject
Next Message Robert Haas 2011-06-01 20:58:36 Re: [PERFORM] Hash Anti Join performance degradation
Previous Message Robert Haas 2011-06-01 20:43:29 Re: [PERFORM] Hash Anti Join performance degradation