AW: [UMN_MAPSERVER-USERS] Mapfile Tuning

[Stephen Woodbridge]

Pleyer, Walter wrote:
> Hi Steven!
> 
> We are using a mix of raster and shape files.
> We compared the "fat" mapfile with a "slim" mapfile, that contained only
> the layers, that we wanted to parse and the latter one was a lot faster.
> Debug output showed that actually loading those layers and rendering the
> map was equally fast, so obviously the loss on performance is connected
> to the number of not displayed layers.
> 
> What I forgot to mention was the system: We are using Windows 2003 and
> IIS on a 4 Xeon machine.

OK, well this may not be the performance of "loading" the extra layers 
then, it may be the performance of having a lot of layers loaded that 
are not displayed, if you get the difference. One would therefore want 
to look in a different place for the the performance issue.

I wrote a simple mapscript routine and timed the cost to create an new 
map object. This code is basically just loading the mapfile and doing 
nothing else. It is very fast, like typically 0.1 sec for most large 
mapfiles. So the issue is unlikely with the mapfile parser.

-SteveW