[OSM-dev] arbitrariness of relations [was: HEADS UP osmosis pgsql schema users]

[Roland Olbricht]

Dear all,

> Hugh Barnes wrote:
> > I had a very different different idea of what relations were before I
> > looked at them properly. I was disappointed to see that they just appear
> > to be named groupings. …
>
> They are what you make them to be.

I think, relations are exactly *not* that way. Of course, there is no formal 
prohibition or technical constraint. But the purpose of any data including 
relations is to be understood by another algorithm. So a type of relation 
becomes useful if a lot of mappers use it with the same syntax and semantics. 
Thus, maintaining relations coherent by e.g.
http://wiki.openstreetmap.org/index.php/Relations
sounds like a good idea, and maybe its also a good idea to donate some life 
the discussion process there. Thus, also people not reading this list can 
participate. Note that the relations in the database currently only rarely 
obey the consensus on the wiki page, but this might change as with the 
proposed features page.

Cheers,
Roland