[OSM-talk] OSM relation ID property in Wikidata

[Peter Wendorff]

Am 07.05.2013 09:43, schrieb Stefan Keller:
> Hi,
> 
> All use cases you describe are valid. It's up to the users of OSM
> permanent id to keep track of changing OSM ids - it's an offer of OSM.
> The only constraint I would propose is to avoid to delete and recreate
> a new id only because of a tool (like an editor) likes to do it like
> this.
> 
> The concept of permanent, unique and never-reused object ids is a
> well-known property in the Object-Oriented and Linked Data technology.
> 
> As I said: The killer criteria not to use overpass-approach is that
> there exist many OSM objects which have too few or no tags at all. And
> using coordinates as identifiers is no solution neither because it's a
> float number with different precision and implementation dependent. OO
> overcame exactly this restriction of the relational paradigm (which
> identified a tupel by the set of it's values).

But even then overpass is slightly better:
Let's say I only know I want to link a given supermarket.
Let's say that supermarket is not tagged in more detail then
shop=supermarket.
Linking to node 123 would break soon when that get's a polygon (not to
mention mappers who don't know or care about theory of data management
and reuse that node directly to map a waste_basket instead of creating a
new object).
Best case here would be a mapper that includes that node as one of the
nodes building the polygon - but who knows?

Overpass in contrast could add information about:
- we want to link a supermarket
- it's roughly in that bounding box (e.g. the city or a given part of
the city)

Of course this can break, too - but it's more stable than the ID alone,
even without any tag at all.

regards
Peter