[OSM-talk] Tagging OSM objects with UUIDs
frederik at remote.org
Mon Jun 7 10:01:54 BST 2010
John Smith wrote:
> I think you have misunderstood or at least not comprehended the
> potential for being able to easily share the same ID with other
> databases without needing to do special or complex bbox searches like
> you suggest.
It doesn't exactly require a stroke of genius to see that potential,
given that people are already using our internal IDs all over the place
for lack of something better.
It does, however, require a stroke of genius to find a non-invasive and
permanent way to solve this problem. Tagging objects with UUIDs is neither.
> It might do so, but it's horribly inefficient as a result of needing
> to do searches across areas, and can't cope with an occupant such as a
> business moving across town
If you investigate the use cases for permantent IDs further, you will
find that "moving across town" is often a valid reason for actually
discarding the ID. As in, someone writes a travel guide and wants to
link to a restaurant ("Chez Fred, an excellent pizza joint in the heart
of Hamburg with views on the Elbe river traffic..."). Now if "Chez Fred"
moves across town and is replaced, at the same location, with "Chez
John", is it useful for the travel guide to still be able to link to
"Chez Fred"? - Of course, if the travel guide said: "Chez Fred, an
excellent pizza joint in Hamburg where renowned chef Frederik Ramm
entertains his guests to Pizza Margherita every Tuesday", then it would
have made sense to keep the link despite the move (but perhaps not so if
the owner=... tag had changed...)
For every kind of object and every context in which you link to it, the
change of some properties might invalidate the link. That's why UUIDs
are not only clumsy but also not solving the problem.
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