[OSM-talk] Broken Ways, WMS Server Status

Immanuel Scholz immanuel.scholz at gmx.de
Fri Apr 28 13:48:28 BST 2006


>> Its "prevented" in terms of the problem with JOSM is fixed now. I don't
>> see a reason to prevent this in the server, since something like this is
>> usually silly and nobody will enter it anyway (except for a reason).
> My main concern is that it ruins the usability of OSM's data -- one
> assumption that I was going to make was that ways are made up of unique
> segments, but that's obviously not the case.

Hm, I don't see the a real problem here. If you have an application that
cannot live with ways having the same segment twice, then a conversion of
the XML input is done very easily (my uniq-trick is not 100%, but gives a
good start ;-).

I hope we can soon have several small mini-API-implementations with
exporting thoose constraints that are wanted by the different application
types (e.g. for routing, you have several other things that would make
your live much easier).

But for this particular issue: JOSM now also assume that a way should not
have multiple segments (you can't enter them anymore).

> This isn't to neccesarily say that the database should prevent ways from
> having the same segment multiple times, since I'm sure there's costs to
> that.

Yep. There are coses in complexity of the data, server implementation and
data definition design as well as in speed.

> The problem with this is that it *isn't* obvious to most people using the
> applications, since multiple segments being selected in a way isn't
> something that you can graphically represent in an intuitive manner.

Yep. And that's the reason you can't do such things in JOSM anymore ;-)

Ciao, Imi

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