[OSM-talk] Admin borders/separate database

[Christoph Hormann]

On Tuesday 05 November 2013, Jochen Topf wrote:
> [...] And it is
> totally unclear how things that are supposed to be changed together
> (think borders following a river or road) are to be handled.

And in principle the OSM data strctures are quite good for this, you can 
have a way with waterway=* that is part of a boundary relation.

In reality borders are nearly always defined either through some real 
feature that is map-worthy in OSM on its own (most frequently rivers or 
watershed divides) or by straight lines/arcs between points with 
specified coordinates.  The practical problem is that borders are 
mostly imported from external sources which do not contain the actual 
definition of the border but an approximation of varying accuracy.  The 
only place where i have seen truely definition based borders in OSM are 
maritime boundaries like:

http://www.openstreetmap.org/browse/way/48854191

-- 
Christoph Hormann
http://www.imagico.de/