[postgis-users] Dted elevations

[Pierre Racine]

What happened when you remove "and st_value (dted_elevations.rast, f.geom) is not null"? You get null values?

Do you have many nodata values in your raster?

How is your raster tiled? Did you build a spatial index on the raster tiles?

Pierre

> -----Original Message-----
> From: postgis-users-bounces at lists.osgeo.org [mailto:postgis-users-
> bounces at lists.osgeo.org] On Behalf Of Gold, Jack L (US SSA)
> Sent: Friday, May 09, 2014 1:01 PM
> To: 'postgis-users at lists.osgeo.org'
> Subject: [postgis-users] Dted elevations
> 
> I know this question has already been answered a hundred times but I am
> at a remote location currently with only email access right now and I hope
> someone can help.  The following query is taking close to a second to run
> and I think it should be much faster.
> 
> Select st_value from (with f as ( select st_transform ( st_SetSRID(
> st_MakePoint('106','32'), 4326) as geom) select
> st_value(dted_elevations.rast, f.geom) from dted_elevations cross join f
> where st_intersects ( dted_elevations.rast , f.from) and st_value
> (dted_elevations.rast, f.geom) is not null) as st_value;
> 
> Any help is greatly appreciated.
> 
> Jack Gold
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