[mapserver-users] Thousands of layers?

[James Jefferson]

Hello everyone,

I've been using mapserver for about a year now and one of the problems I've 
struggled with is making a detailed map of the United States - down to the 
street level.

I have Shapefiles generated from the 1997 TIGER, broken down by county. I've 
noticed in the mapserver documentation that there is a limit of 50 layers per 
mapfile (incidentally, the define in map.h is set to 100). There are a few 
thousand counties in the US, and consquently I think I need a approximately 
20,000 shapefiles to represent the different layers for each county.

If I recompile mapserver with MS_MAXLAYERS set higher, how will that affect 
performance? Looking at source it appears that the MS_MAXLAYERS is just used 
to allocate memory for each layer. How does mapserver decide what maps to 
load? I'm assuming it uses the bounding boxes associated with each shapefile 
to determine what file to load? If so, are those read each time mapserver is 
invoxed, or can it have a index file?

Is anybody else using mapserver for this scale? Advice? Am I on the right 
track at all?

Thanks,

-James Jefferson
Winona, Minnesota