Received: from localhost (maia-5.hub.org [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id 346629F965B for ; Tue, 21 Aug 2007 08:39:41 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-maia, port 10024) with ESMTP id 84877-08 for ; Tue, 21 Aug 2007 08:39:25 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from smtp-vbr2.xs4all.nl (smtp-vbr2.xs4all.nl [194.109.24.22]) by postgresql.org (Postfix) with ESMTP id 5F7439F9646 for ; Tue, 21 Aug 2007 08:39:29 -0300 (ADT) Received: from webmail.xs4all.nl (dovemail9.xs4all.nl [194.109.26.11]) by smtp-vbr2.xs4all.nl (8.13.8/8.13.8) with ESMTP id l7LBdOhH082694; Tue, 21 Aug 2007 13:39:26 +0200 (CEST) (envelope-from jtv@xs4all.nl) Received: from 58.136.19.146 (SquirrelMail authenticated user jtv) by webmail.xs4all.nl with HTTP; Tue, 21 Aug 2007 18:39:27 +0700 (ICT) Message-ID: <20140.58.136.19.146.1187696367.squirrel@webmail.xs4all.nl> In-Reply-To: <200708181610.28918.sdc@sdc.com.au> References: <200708181610.28918.sdc@sdc.com.au> Date: Tue, 21 Aug 2007 18:39:27 +0700 (ICT) Subject: Re: Query performance From: "Jeroen T. Vermeulen" To: "Stephen Davies" Cc: pgsql-interfaces@postgresql.org User-Agent: SquirrelMail/1.4.8 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Virus-Scanned: by XS4ALL Virus Scanner X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200708/6 X-Sequence-Number: 6600 On Sat, August 18, 2007 13:40, Stephen Davies wrote: > select count(rdate),rdate from reading where sensor_id in > (1137,1138,1139) group by rdate order by rdate desc limit 1; > > takes a few seconds but: Interesting! However this is probably not the best list to ask, since it's about the backend and quite independent of any interface. You may have more luck on pgsql-general. Jeroen