Hi, I imagine you define suitable index on raster table ? You could maybe try to add a functional index on ST_VALUE(rast,geom) != 0.
I'm wondering if grouping by geom is very efficient ? If your data are clearly separated, you could try to group by the geometry's bbox instead, to see if it speeds up the query. Are your data large ? Creating a buffer of 10000 unit can take some time. If your data are points, you should use st_dwithin(geom, distance) to test if points are within the raster or not. Nicolas On 21 August 2013 10:03, Nathaniel Clay <[email protected]> wrote: > Hi all, > > I am having trouble geting the following query to run in a efficient manner: > > Select ST_AsText(point) as point,ST_WorldToRasterCoordX(raster,point) as > cx,ST_WorldToRasterCoordY(raster,point) as > cy,ST_AsGDALRaster(raster,'GTiff') as image from ( SELECT geom as point, > ST_UNION(ST_CLIP(rast,ST_BUFFER(geom,10000))) as raster from wv_ned_utm83 , > pointsouth where ST_INTERSECTS(rast,ST_Buffer(geom,10000)) and > ST_VALUE(rast,geom) != 0 GROUP BY geom limit 1 ) as foo" > > Any suggestions or help would be greatly appreciated!! > > Thanks, > > Nathaniel Hunter Clay > _______________________________________________ > postgis-users mailing list > [email protected] > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
