[postgis-users] value of spatial index on 300, 000, 000 point geometries

[Paul Ramsey]

On Tue, May 5, 2009 at 9:58 PM, Kevin Neufeld <kneufeld at refractions.net> wrote:
>  But (and folks can correct me if I'm wrong since the docs don't actually
> specify) transforms operate on *all* dimensions.
> postgis=# select st_asewkt(st_transform('SRID=3005;POINT(1240227 495643 5)',
> 4001));
>                             st_asewkt
>  ----------------------------------------------------------------------
> SRID=4001;POINT(-122.689717977579 49.4258574870912 533.550271589169)
> (1 row)

That's news to me and my version of PostGIS:

medford=# select st_asewkt(st_transform('SRID=3005;POINT(1240227
495643 5)', 4001));
                       st_asewkt
-------------------------------------------------------
 SRID=4001;POINT(-122.689717977579 49.4265525863074 5)
(1 row)

My intuition was that reprojection would leave Z alone, since proj4
has no z-transform capabilities.

P.