Received: from localhost (maia-2.hub.org [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id 4108B9FB24A for ; Tue, 28 Nov 2006 12:25:28 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-new, port 10024) with ESMTP id 46814-05 for ; Tue, 28 Nov 2006 12:25:12 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id CE2389FB22F for ; Tue, 28 Nov 2006 12:25:18 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.6/8.13.6) with ESMTP id kASGOgYL006537; Tue, 28 Nov 2006 11:24:42 -0500 (EST) To: "Gopal" cc: "Frank Wiles" , "Guido Neitzer" , pgsql-performance@postgresql.org, postgis-users@postgis.refractions.net Subject: Re: Postgres scalability and performance on windows In-reply-to: References: Comments: In-reply-to "Gopal" message dated "Tue, 28 Nov 2006 12:22:31 +0000" Date: Tue, 28 Nov 2006 11:24:42 -0500 Message-ID: <6536.1164731082@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200611/250 X-Sequence-Number: 22020 "Gopal" writes: > This is the query and the schema.... > ... > select > sum(area(intersection(snaptogrid(chunkgeometry,0.00000001), > GeometryFromText('POLYGON((-0.140030845589332 > 50.8208343077265,-0.138958398039148 50.8478005422809,-0.0963639712296823 > 50.8471133071392,-0.0974609286275892 50.8201477285483,-0.140030845589332 > 50.8208343077265))',4326))) * 100/ (0.00114901195862628)) as > percentCover, So evidently area(intersection(snaptogrid(...))) takes about 300 microsec per row. The PostGIS hackers would have to comment on whether that seems out-of-line or not, and whether you can make it faster. regards, tom lane