[postgis-users] calculate profile on raster

[Pierre Racine]

> I need to calculate a raster profile along a linestring.
> The only way I've found is using ST_Intersection(rast,geom) but it seems to
> provide poor perfomances (even with ST_Intersects), probably because of the
> rast->geom conversion.
> Is there a better way to do it?
> 
> My query is:
> > select st_intersection(rast,the_geom) from dem,profile where st_intersects
> (rast,the_geom)
> I have the gist index both on rast and the_geom.

Did you tile your raster? Smaller is better...

Pierre