[ka-Map-users] Data handling...

[Delfos, Jacob]

Scott,

Theoretically, there should not be much difference between using a
tileindex (where each shapefile has a mapserver .qix spatial index) and
using one file with one spatial index. But in practice there may be. I
try not to let my shapefiles get bigger than a few hundred megabytes.
And with a file of that size, I would not allow the whole file to be
drawn too often (using maxscale). With Ka-Map and pre-caching, it might
be alright, though.

I suggest you either make them one shapefile if it is not too big, or
create a tileindex, but still create a spatial index for each shapefile.

What resolution is your global mosaic? Again it depends on your system.
I have good experiences using single large ECW's, but if you system has
fast harddisks, you may get away with uncompressed TIF's, and then using
a tileindex (reducing loan on CPU). Or you can use smaller ECW's and use
a tileindex. You can also use a tileindex in combination with an
overview image of lower resolution, which is only shown at larger scales
(use minscale and maxscale). That is the approach I use.

Regards,

Jacob



> -----Original Message-----
> From: ka-map-users-bounces at lists.maptools.org 
> [mailto:ka-map-users-bounces at lists.maptools.org] On Behalf Of 
> Scott Knutti
> Sent: 24 May 2006 06:51
> Cc: ka-map
> Subject: [ka-Map-users] Data handling...
> 
> Hello,
> 
> I am building a kaMap/Mapserver application and I'm trying to display 
> data across the country.   I have shapefiles from each state 
> for about 
> 15-20 different layers, some of them (like the local roads) are very 
> large.  Is it best to merge these shapefiles, then index 
> them?  Or just 
> create tileindexes?  Or merge some and leave the large ones?  Also, I 
> have the global mosaic dataset from NASA that needs to be displayed.  
> How do I go about massing those files so that they display in a 
> reasonable amount of time?
> 
> Thanks to all!
> 
> Scott
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