X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id AB89411F662E for ; Thu, 30 Mar 2006 08:59:13 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 42842-05 for ; Thu, 30 Mar 2006 08:59:13 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from gauss.credativ.com (ipx11302.ipxserver.de [212.112.227.254]) by postgresql.org (Postfix) with ESMTP id 963BA11F6645 for ; Thu, 30 Mar 2006 08:59:11 -0400 (AST) Received: from bell.credativ.de (p50896DF7.dip.t-dialin.net [80.137.109.247]) (using TLSv1 with cipher EXP1024-RC4-SHA (56/128 bits)) (No client certificate requested) by gauss.credativ.com (Postfix) with ESMTP id A49C6D75F4; Thu, 30 Mar 2006 14:59:07 +0200 (CEST) From: Peter Eisentraut To: "Steinar H. Gunderson" Subject: Re: Index scan startup time Date: Thu, 30 Mar 2006 14:59:02 +0200 User-Agent: KMail/1.8.3 Cc: pgsql-performance@postgresql.org References: <200603301359.11038.peter_e@gmx.net> <200603301423.54510.peter_e@gmx.net> <20060330123134.GA13408@uio.no> In-Reply-To: <20060330123134.GA13408@uio.no> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Content-Disposition: inline Message-Id: <200603301459.03011.peter_e@gmx.net> X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.105 required=5 tests=[AWL=0.105] X-Spam-Score: 0.105 X-Spam-Level: X-Archive-Number: 200603/616 X-Sequence-Number: 18053 Am Donnerstag, 30. März 2006 14:31 schrieb Steinar H. Gunderson: > Well, it's logical enough; it scans along activity_id until it finds one > with state=10000 or state=10001. You obviously have a _lot_ of records with > low activity_id and state none of these two, so Postgres needs to scan all > those records before it founds 100 it can output. This is the “startup > cost” you're seeing. The startup cost is the cost until the plan is set up to start outputting rows. It is not the time until the first row is found. -- Peter Eisentraut http://developer.postgresql.org/~petere/