I am probably not the best to answer how it is used because we use it just to allow index on spatial data (coordinates). You may ask on the postgis mailing list.
Woody
From:pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Bob Pawley Sent: Thursday, October 19, 2006 11:09 AM To: Postgresql Subject: [GENERAL] PostGIS
Can anyone point me to an overview of PostGIS and how it is being used???