tiles and overview maps

[Frank Rittinger]

Hello list,

I know this subject came up a hundred times, but I couldn't find an 
answer to my questions.

I'm used to using gdaltindex if I have several raster images to create a 
tile index for them.  But what if I want to tile one large image?  I 
understand that when I have only one large image and I want it tiled, I 
have to use gdalwarp or gdal_transform with the TILED=YES switch.  This 
produces only one large image.  Is this it, or do I have to use 
gdaltindex for this somehow?  Do I have to use a regular raster layer or 
a tileindex layer with this one large TIFF image?  Or do I need other 
command line switches to get many TIFF-images?

Second, if I use gdaladdo to produce overview images, I think they are 
all stored in the same file.  Do I need only one layer and mapserver 
takes the right image according to the current zoom, or do I hav to use 
more than one layer with minscale, maxscale?  But than, which image do I 
use for those layers?

Regards,	Frank