[OSM-talk] House numbers... One more suggestion

Frederik Ramm frederik at remote.org
Mon Jul 28 19:15:46 BST 2008


Karl Newman wrote:
> Given a street, I'd have to look through NN million nodes to find the 
> closest ones

No. The nodes are tagged with street names, thus duplicating info found 
on the way. You just need an index on that field, look up the street 
name in the index, and immediately know all addresses entered for that 

THEN, if you want to know how many meters from house number 13 to house 
number 723, you have to compute the nearest point on the nearest way for 
13 and 723 and find the distance.

That being said, some people actually add relations to make things extra 
clear (see bottom of KS page). The reason we don't force people to add 
relations is that it seemed too much to ask - we'd rather make it a bit 
more difficult for the data user than for the mapper. The Karlsruhe 
Schema was made with mappers in mind, who enter house numbers manually. 
Had it been a schema designed for importing data from another source, we 
might have opted for a more complex data model, saying that nobody has 
to enter it anyway...

But as I've said a number of times - I wouldn't feel the least offended 
if someone else tried another scheme.


Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"

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