Received: from localhost (maia-1.hub.org [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id D44DC9FC04A for ; Wed, 9 May 2007 11:34:07 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-maia, port 10024) with ESMTP id 47334-01 for ; Wed, 9 May 2007 11:34:02 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from oxford.xeocode.com (unknown [62.232.55.118]) by postgresql.org (Postfix) with ESMTP id C643A9FC027 for ; Wed, 9 May 2007 11:34:02 -0300 (ADT) Received: from localhost ([127.0.0.1] helo=oxford.xeocode.com) by oxford.xeocode.com with esmtp (Exim 4.67) (envelope-from ) id 1HlnEu-0002R9-R4; Wed, 09 May 2007 15:34:00 +0100 From: Gregory Stark To: "Daniel Cristian Cruz" Cc: Subject: Re: Nested loops overpriced In-Reply-To: <48d0cacb0705090638p54f7ccbcg90270b889c8900a1@mail.gmail.com> (Daniel Cristian Cruz's message of "Wed, 9 May 2007 10:38:56 -0300") Organization: EnterpriseDB References: <200705081722.16731.peter_e@gmx.net> <1987.1178639593@sss.pgh.pa.us> <200705091358.25748.peter_e@gmx.net> <48d0cacb0705090638p54f7ccbcg90270b889c8900a1@mail.gmail.com> X-Draft-From: ("nnimap+mail01.enterprisedb.com:INBOX.performance" 310) Date: Wed, 09 May 2007 15:34:00 +0100 Message-ID: <87sla6gj6v.fsf@oxford.xeocode.com> User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200705/194 X-Sequence-Number: 24584 "Daniel Cristian Cruz" writes: > -> Nested Loop (cost=0.00..13187.94 rows=93 width=4) (actual time=2.622..125.739 rows=50 loops=1) > -> Seq Scan on u (cost=0.00..2838.80 rows=10289 width=4) (actual time=0.012..9.863 rows=10291 loops=1) > -> Index Scan using m_pkey on m (cost=0.00..0.80 rows=1 width=7) (actual time=0.009..0.009 rows=0 loops=10291) That's not discounting the nested loop for cache effect at all! What is your effective_cache_size for this? -- Gregory Stark EnterpriseDB http://www.enterprisedb.com