Received: from localhost (maia-1.hub.org [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id 95B329FBBE0 for ; Thu, 5 Apr 2007 02:11:38 -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 55403-01-10 for ; Thu, 5 Apr 2007 02:11:30 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.126.174]) by postgresql.org (Postfix) with ESMTP id D5E819FBBA5 for ; Thu, 5 Apr 2007 02:11:29 -0300 (ADT) Received: from [194.25.154.138] (helo=webserv.wug.de) by mrelayeu.kundenserver.de (node=mrelayeu8) with ESMTP (Nemesis), id 0ML31I-1HZKFs1LaZ-0005xw; Thu, 05 Apr 2007 07:11:28 +0200 Received: from kretschmer by webserv.wug.de with local (Exim 3.36 #1) id 1HZKFr-0006WO-00 for pgsql-sql@postgresql.org; Thu, 05 Apr 2007 07:11:27 +0200 Date: Thu, 5 Apr 2007 07:11:27 +0200 From: "A. Kretschmer" To: pgsql-sql@postgresql.org Subject: Re: slow query Message-ID: <20070405051127.GA24814@a-kretschmer.de> References: <7539aebb0704042017l70d83d53u9c2e5105620a3fa7@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7539aebb0704042017l70d83d53u9c2e5105620a3fa7@mail.gmail.com> X-OS: Debian/GNU Linux - weil ich es mir Wert bin! X-Message-Flag: "Windows" is not the answer. "Windows" is the question and the answer is "no"! User-Agent: Mutt/1.5.9i X-Provags-ID: V01U2FsdGVkX19vBOFbEJxALPC63XiHPQoB0X6ROPAL5TRG9Kk +Ixf8B2uMmeIT8sHi0ASosL6dWB2o324HkIb2adJDQaUrigoK+ gpqXnpDuFL5jNpvVktMqo/KgbxOLUFu X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200704/63 X-Sequence-Number: 28063 am Wed, dem 04.04.2007, um 23:17:54 -0400 mailte Sumeet folgendes: > sm=> explain analyze select * from ma limit 10; > QUERY > PLAN > ------------------------------------------------------------------------------------------------------------------------------------- > Limit (cost=0.00..0.45 rows=10 width=76) (actual time=21985.292..22204.340 > rows=10 loops=1) > -> Seq Scan on ma (cost=0.00..2181956.92 rows=48235392 width=76) (actual > time=21985.285..22204.308 rows=10 loops=1) > Total runtime: 22204.476 ms > (3 rows) which version? I have 8.1 and on a table with 1.9 million records i got: scholl=# explain analyse select * from bde_meldungen limit 10; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------- Limit (cost=0.00..0.34 rows=10 width=157) (actual time=19.570..19.660 rows=10 loops=1) -> Seq Scan on bde_meldungen (cost=0.00..65748.33 rows=1957933 width=157) (actual time=19.565..19.587 rows=10 loops=1) Total runtime: 19.845 ms (3 rows) If I remember correctly, since 8.0 or 8.1 we have a massive improvement with LIMIT. Andreas -- Andreas Kretschmer Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header) GnuPG-ID: 0x3FFF606C, privat 0x7F4584DA http://wwwkeys.de.pgp.net