[mapguide-users] MrSID files through GDAL FDO provider

[Frank Warmerdam]

Martin Morrison wrote:
> If the mapguide tries each provider in order to open an image, how much
> performance gain is there by only using one raster format and compiling
> only that driver?  Or can you specify the order in which the drivers are
> polled?

Martin,

There would be no appreciable improvement in performance - at least
for files that actually open.  The case that the "test each in sequence"
thing tends to get inefficient is for files that fail to open because then
all the drivers are tested.  And there are sometimes a few drivers at the
bottom of the list that are somewhat expensive.  For instance, probing for
header files and such.

It is possible to only register required drivers but I think this is a
relatively pointless optimization in the grand scheme of things.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGeo, http://osgeo.org