Superb. That's clear to me. Thanks again, V From: [email protected] [mailto:[email protected]] On Behalf Of Bryce L Nordgren Sent: Thursday, August 11, 2011 2:16 PM To: PostGIS Users Discussion Subject: Re: [postgis-users] spatial indices on two geometry or rast columns
[email protected]<mailto:[email protected]> wrote on 08/11/2011 08:56:44 PM: > I am not planning to cearch using utm coordinates. The main reason I > would create a utm geom, was so that I could calculate areas, > distances in sq km easily without having to include nested > ST_TRANSFORM statements. In this case would it be useful to have > another index on the utm? I'd say that a good rule of thumb would be: If the WHERE clause of your SELECT statement names a geometry column, make an index on that column. If the column isn't in the WHERE clause, don't bother. :) Bryce
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