X-Original-To: pgsql-sql@postgresql.org Received: from spampd.localdomain (postgresql.org [64.49.215.8]) by postgresql.org (Postfix) with ESMTP id 6AFD5475C3D for ; Thu, 17 Apr 2003 10:13:04 -0400 (EDT) Received: from megazone.bigpanda.com (megazone.bigpanda.com [63.150.15.178]) by postgresql.org (Postfix) with ESMTP id 9FB74475F1B for ; Thu, 17 Apr 2003 10:12:33 -0400 (EDT) Received: by megazone.bigpanda.com (Postfix, from userid 1001) id EE24CD613; Thu, 17 Apr 2003 07:12:37 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by megazone.bigpanda.com (Postfix) with ESMTP id E3A9D5C03; Thu, 17 Apr 2003 07:12:37 -0700 (PDT) Date: Thu, 17 Apr 2003 07:12:37 -0700 (PDT) From: Stephan Szabo To: Rajesh Kumar Mallah Cc: Subject: Re: planner question.. In-Reply-To: <200304171927.08124.mallah@trade-india.com> Message-ID: <20030417071102.V87131-100000@megazone23.bigpanda.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Status: No, hits=-26.4 required=5.0 tests=BAYES_00,EMAIL_ATTRIBUTION,IN_REP_TO,QUOTED_EMAIL_TEXT, QUOTE_TWICE_1,REPLY_WITH_QUOTES autolearn=ham version=2.50 X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.50 (1.173-2003-02-20-exp) X-Archive-Number: 200304/268 X-Sequence-Number: 12969 On Thu, 17 Apr 2003, Rajesh Kumar Mallah wrote: > I think there shud be more documentation on > understanding EXPLAIN (ANALYZE) output. > once i found an webpage but lost it. I believe there's one inside the docs on performance or optimization. > > where do u see its expecting 5000 not 100000? > > > | Aggregate (cost=23982.58..23982.58 rows=1 width=0) (actual > > > | time=22872.97..22872.97 rows=1 loops=1) | -> > > > | Seq Scan on profile_master (cost=0.00..23970.40 rows=4871 width=0) > > > | (actual time=328.44..22730.69 rows=102090 loops=1) | In the Seq Scan line, it's got rows=4871. That's the number it thinks are going to match the filter/index condition.