[mapserver-users] Using Fast CGI with MapServer toalleviatepoorperformance [SOLVED]

Guillaume Sueur guillaume.sueur at neogeo-online.net
Sun Sep 21 04:05:52 EDT 2008

Hi John,

Interesting results indeed !

> The ironic thing is that I used the projection string instead of the epsg code so I could avoid the lookup so it would be faster! I do not understand why MapServer does an unnecessary reprojection with OpenLayers.WMS and the projection string; shouldn't it be able to determine that the projection string is the same as the epsg number? I guess, that would probably involve a lookup, thus rendering the use of the projection string in place of the epsg code ineffectual.
For the reprojection thing, I don't think there is a perfect solution.
As WMS uses EPSG codes, mapserver would have to scan the whole epsg file
on each projection definition to find the matching epsg-proj pair, and
it could take a long time, much longer than simply scanning the epsg
file to find the proj string for a specific epsg code.
I think the best solution for you is to use a custom epsg file with only
 the definitions you need in it, and keep using epsg codes in your
mapfile, which ensures full compatibility with WMS usage.

> Thanks again for all the help, it would have taken me much longer to solve the problem on my own!

Your welcome. It's always interesting to face such problems and discover
the bottlenecks. This is helpful for all of us.

Best regards,


> Regards
> John Westwood
> Great Britain Historical GIS Project
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users

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