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 EDDB09DCE13 for ; Sat, 18 Mar 2006 10:58:51 -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 50536-02 for ; Sat, 18 Mar 2006 10:58:55 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from wolff.to (wolff.to [66.93.197.194]) by postgresql.org (Postfix) with SMTP id 433009DCE12 for ; Sat, 18 Mar 2006 10:58:49 -0400 (AST) Received: (qmail 10145 invoked by uid 500); 18 Mar 2006 15:00:19 -0000 Date: Sat, 18 Mar 2006 09:00:19 -0600 From: Bruno Wolff III To: Oleg Bartunov Cc: Michael Fuhr , Tom Lane , Dan Harris , PostgreSQL Performance Subject: Re: Help optimizing a slow index scan Message-ID: <20060318150019.GA8398@wolff.to> Mail-Followup-To: Bruno Wolff III , Oleg Bartunov , Michael Fuhr , Tom Lane , Dan Harris , PostgreSQL Performance References: <4419DB50.10404@drivefaster.net> <441B1FC6.60001@drivefaster.net> <12823.1142656871@sss.pgh.pa.us> <20060318052941.GA46733@winnie.fuhr.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.102 required=5 tests=[AWL=0.102] X-Spam-Score: 0.102 X-Spam-Level: X-Archive-Number: 200603/305 X-Sequence-Number: 17742 On Sat, Mar 18, 2006 at 11:50:48 +0300, Oleg Bartunov wrote: > I may be wrong but we in astronomy have several sky indexing schemes, which > allows to effectively use classical btree index. See > http://www.sai.msu.su/~megera/oddmuse/index.cgi/SkyPixelization > for details. Sergei Koposov has developed Q3C contrib module for > PostgreSQL 8.1+ and we use it with billiard size astronomical catalogs. Note that Earth Distance can also be used for astronomy. If you use an appropiate radius, distances will be in degrees.