> "xmin" is actually a PostgreSQL system column used for transactions, > not a PostGIS function.
Sorry, actually st_xmin is the function I'm after. I want to select the whole table ordered by minimum x coordinate of the gemertries. When I do it the naive way postgresql needs half an hour to prepare the ordering before the first results are delivered, since my table is quite large. I thought that it could be somehow possible to skip this time since the ordering is already stored in the index on the geometry column... On 17 May 2012 03:05, Melchior Moos <melchior.moos at 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
