[postgis-users] PostGIS-PostgreSQL

Peter N. Schweitzer pschweitzer at usgs.gov
Mon Jul 13 08:17:57 PDT 2009


Chris Hermansen wrote:
> I should have mentioned that it's not considered good practice to
> have more than one geometry column per table, and hence more than
> one geometry object per row. This makes sense if you think of rows
> as representational instances of real world objects.

Hmmm.  I'm storing two geometry columns, because in one I have the
geographic (unprojected) coordinates, and in the other the coordinates
in some projection.  This is to support several different map interfaces
some of which are projected, others not.  Since the points don't change
frequently, I can generate the projected coords once and then simply
use them rather than recalculate them on every web hit.  It's denormalized,
but seems sensible to me.  Would you disagree with this method?

Peter
-- 
Peter N. Schweitzer (MS 954, U.S. Geological Survey, Reston, VA 20192)
(703) 648-6533  FAX: (703) 648-6252  email: pschweitzer at usgs.gov
<http://geology.usgs.gov/peter/>



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