Performance hints please

[Stephen Davies]

Yes, I see the overviews in the gdalinfo output.
So far, I have only used 50%. Any guides as to what is a good number of 
overviews to create?
How does mapserv chose which overview to use? What is "appropriate"?

Cheers,
Stephen

On Thursday 20 April 2006 12:42, Frank Warmerdam wrote:
> Stephen Davies wrote:
> > G'day Frank.
> >
> > I reread the raster howto etc on overviews and do think they might
> > help.
> >
> > I have created some overviews of my TIFF images using gdaladdo but
> > cannot see how to tell mapserv to use them. Could you please give
> > me a pointer.
>
> Stephen,
>
> It should just use them automatically when they are appropriate for
> the current map request.  You might want to verify that GDAL sees the
> overviews by running "gdalinfo" on the dataset after gdaladdo, and
> ensuring there are some overviews levels listed after the bands in
> the report.
>
> There isn't any particularly easy way to ensure that mapserver is
> using the overviews short of seeing better performance.
>
> Best regards,

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