[Gdal-dev] Geometry Collection

Radim Blazek blazek at itc.it
Tue Jun 10 05:13:19 EDT 2003

Can Geometry Collection (GC) in OGR contain other GC, i.e. tree of GC without any
limits on number of levels? 

Is it possible in SFS? It seems, that it is possible [1].

Does it make any sense to have GC of GC tree? I don't think so. 
Are there any applications where such trees are useful? 
Does any SW producing such trees exist?

BTW: Collect() in PostGIS returns just one simple GC containing basic geometries
instead of GC of GC tree. 


[1] "2.1.2 Geometry Collection 
A GeometryCollection is a geometry that is a collection of 1 or more geometries. 
GeometryCollection places no other constraints on its elements. 
Subclasses of GeometryCollection may restrict membership based on dimension 
and may also place other constraints on the degree of spatial overlap between elements."

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