[postgis-users] "GEOMETRY" type

David Blasby dblasby at refractions.net
Fri Sep 19 09:10:35 PDT 2003

Benjamin Wragg wrote:
> Hi list
> When it comes to create feature tables in PostGIS I've been using one 
> type of geometry per table e.g points in one table and polygons in 
> anther. I can across the "GEOMETRY" or
> "GEOMETRYCOLLECTION" type in the PostGIS documents which I hadn't seen 
> before. Is there any problems/limitation with using this? Do all other 
> PostGIS function work ok with layers of this types, eg distance, &&, 
> intersect, etc?

I suggest you make the type "GEOMETRY" (using AddGeometryType()) for 
your table - then you can stick any geometry type inside.

If you make things GEOMETRYCOLLECTION you'll probably find things more 
difficult to use because there's only a few functions that actually 
manipulate them (ie. GetGeometryN(), NumGeometries()).  Plus the GEOS 
routines are not well defined for GEOMETRYCOLLECTIONs.


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