[OSM-legal-talk] license change effect on un-tagged nodes

Dave F. davefox at madasafish.com
Thu Jul 7 00:14:10 BST 2011


On 06/07/2011 21:04, Anthony wrote:
> On Wed, Jul 6, 2011 at 3:57 PM, Frederik Ramm<frederik at remote.org>  wrote:
>> Dave F. wrote:
>>> If one of these gets moved then the whole way gets updated,
>> No.
> Substantively, that is what happens, but technically, in the database,
> it is not.
>
> In the database, we go from:
>
> <way id=1><nd id=8><nd id=9><nd id=10></way>
> <node id=8 lat=82 lon=18 />
> <node id=9 lat=81 lon=18 />
> <node id=10 lat=81 lon=17 />
>
> to:
>
> <way id=1><nd id=8><nd id=9><nd id=10></way>
> <node id=8 lat=81 lon=17 />
> <node id=9 lat=80 lon=17 />
> <node id=10 lat=80 lon=16 />
>
> Of course, I think that obviously this:
> <node id=8 lat=81 lon=17 />
> <node id=9 lat=80 lon=17 />
> <node id=10 lat=80 lon=16 />
>
> is a derivative of this:
> <way id=1><nd id=8><nd id=9><nd id=10></way>
> <node id=8 lat=82 lon=18 />
> <node id=9 lat=81 lon=18 />
> <node id=10 lat=81 lon=17 />
>
> (assuming a way with, say, 1000 nodes rather than 3...where between 3
> and 1000 you can stop, well, that's a different question)

Well, I learn something new every day.

This explains a lot - as to why entities keep moving but there's no 
record of it.

Can someone please explain the logic of not recording major changes in 
the database such as shifting an entity?

Cheers
Dave F.



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