Hi Melchior, "xmin" is actually a PostgreSQL system column used for transactions, not a PostGIS function.
http://www.postgresql.org/docs/current/static/ddl-system-columns.html The KNN nearest neighbour feature that I think you are describing is the <-> and <#> operators. Check out the documentation for more: http://postgis.refractions.net/docs/geometry_distance_centroid.html http://postgis.refractions.net/docs/geometry_distance_box.html -Mike On 17 May 2012 03:05, Melchior Moos <melchior.m...@gmail.com> wrote: > I recently read that postgis 2.0 can use the index in order by clauses > to find nearest neighbours of geometries. Is there also a way to use > the index for queries like > SELECT * FROM xy ORDER BY xmin(geom); ? > Best regards, > Melchior Moos _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
