From: Tom Lane <tgl@sss.pgh.pa.us>
To: Gopal <gopal@getmapping.com>
Cc: Frank Wiles <frank@wiles.org>
Cc: Guido Neitzer <lists@event-s.net>
Cc: pgsql-performance@postgresql.org
Cc: postgis-users@postgis.refractions.net
Subject: Re: Postgres scalability and performance on windows
Date: Tue, 28 Nov 2006 11:24:42 -0500
Message-ID: <6536.1164731082@sss.pgh.pa.us> (raw)
In-Reply-To: <A5DE6132B8D812419321747E42710E2204C080@EXCHANGE01.gm.local>
References: <A5DE6132B8D812419321747E42710E2204C080@EXCHANGE01.gm.local>
"Gopal" <gopal@getmapping.com> 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
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, gopal@getmapping.com, frank@wiles.org, lists@event-s.net, postgis-users@postgis.refractions.net
Subject: Re: Postgres scalability and performance on windows
In-Reply-To: <6536.1164731082@sss.pgh.pa.us>
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