[mapserver-users] multiple shapefiles in single layer

[Dan Keith]

Hi,

I have a few more questions re: tiling.

The tile4ms utility doesn't support the specification of the TILEITEM 
parameter (i.e., it is always LOCATION), nor does it allow the 
merging of a tile index into an existing tileindex file.

I presume that the only way to create a multicolumn tile index (thus 
allowing the use of multiple TILEITEMs from within the .map file) is 
to write a separate program (e.g., using Perl's XBase module) to 
aggregate multiple tileindex files into a single .dbf file. Is this 
the correct way?

What are the advantages to creating such a multicolumn tileindex, vs 
using separate tileindex file for each logical dataset? Is it more 
efficient?

Also, is it better to create a spatial index from the individual 
shapefiles in a tileindex, or is it better (or even possible) to 
create a spatial index from the composite tileindex?

Thanks


At 11:26 PM -0600 4/3/02, Steve Lime wrote:
>There is a mechanism in the MapServer that already supports this -
>tiling. Basically you create an index shapefile that contains boundaries
>for the various shapefiles in the layers (in you case counties). The
>index shapefile then references the individual shapefiles as an
>attribute. The default attribute is 'location' but you can call it what
>ever you'd like to (then use TILEITEM parameter) and can even use a
>single tile index for multiple layers (e.g. you have roads and lakes
>tiled by county). Support for query of tiled data is supported in
>version 3.5+. See the documentation (and perhaps the wiki) for more
>details.
>
>Steve
>
>Stephen Lime
>Data & Applications Manager
>
>Minnesota DNR
>500 Lafayette Road
>St. Paul, MN 55155
>651-297-2937
>>>>  Joe Bussell <joe at otsys.com> 04/03/02 20:21 PM >>>
>Greetings,
>     I am attempting to combine multiple shapefiles (data from different
>counties) into single layers.  How can I do this without declaring
>multiple layers which must be handled seperately in the mapfile?  Is
>there a standard method which will preserve the ability to querry
>the data?  The mapfile syntax does not seem to allow multiple data tags
>for a given display layer.  This leads me to wonder if there are tools
>which can merge shapefiles into a larger superset.  Is anyone aware of
>such a tool?
>
>Joe Bussell
>On Time Systems

-- 
Dan "Bud" Keith - bud at otsys.com