[Gdal-dev] Performance with .TAB files (Mapinfo Format)

[Frank Warmerdam]

andrea.rogges at virgilio.it wrote:
> Frank,
> thanks very much for your answer.
> 
> The comparison was between Mapserver (+ OGR) and MapInfo Mapxtreme, taking
> the same geographic zone.
> 
> What I've noted during the test was a big difference in 'file system' activity
> (a lot of read bytes with mapserver)... Where can I find the MITAB list?

Andrea,

The MITAB library is hosted at http://mitab.maptools.org/  and the info on
subscribing to the list is available there.

The MITAB library does support spatial indexing.  So a mapserver query
for a small area *should* result only the features in that area being read.
I can't help but wonder if the spatial indexing isn't kicking in for some
reason.

OGR does always read all the attributes of features even if MapServer does
not actually need them.  This can be an issue in some cases.

Performance analysis and tuning is a complex area.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent