[OSM-dev] planet diff and excerpts

[Matthias Julius]

Frederik Ramm <frederik at remote.org> writes:

> Say I have a planet extract containing Germany, and I want to keep  
> that up to date using the planet diffs.
>
> Then I'll just apply the normal (full planet) diffs to my extract and  
> run a new polygon extraction on the result which will give me the  
> updated excerpt, right?
>
> And afterwards I could diff my old data and my new data and thus  
> create a diff that is limited to the excerpted area.
>
> I don't suppose it would be possible to make something like a polygon  
> excerpt from a diff, because the diff doesn't necessarily contain the  
> location where a change occurred (if the change is e.g. in a way).

I think you will have the same problem with your extract. All new ways
referencing existing nodes will end up in it without the nodes. I
guess you will need to plug a filter in between to get rid of
incomplete data.

Matthias