[postgis-users] spatial indices on two geometry or rast columns

[Vishal Mehta]

Superb.
That's clear to me.
Thanks again,
V

From: postgis-users-bounces at postgis.refractions.net [mailto:postgis-users-bounces at postgis.refractions.net] 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



postgis-users-bounces at postgis.refractions.net<mailto:postgis-users-bounces at postgis.refractions.net> 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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