[mapserver-users] raster query strategy

[Jan Hartmann]

  Is this a bug? Shouldn't MapServer use the gdaladdo overviews at the 
appropriate scales?

Jan

On 08/17/10 16:09, Richard Greenwood wrote:
> I am working with a single band raster of 10mX10m cells. I have added
> overlays with gdaladdo and it displays nicely.
>
> When I query the layer I am using MODE=nquery, not MODE=query. The
> reason that I am using nquery is unrelated to the raster layer, but
> I'm pretty much restricted to using that mode. At large scales this
> returns at least 2 cells, which I can average easily with JavaScript
> in the browser. However at small scales I'm getting 10s of 1000s of
> cells which are really slowing things down. It does not appear that
> query or nquery mode is using the overlays. Anyone disagree with that
> assumption?
>
> So the only solution that I've come up with thus far is to resample
> the raster to larger cell sizes and use the min/max scale denominator
> to select a layer with cell size appropriate to the scale. Anybody
> have other ideas?
>
> Thanks,
> Rich
>