[OSM-dev] [OSM-talk] Getting historic information about usage of a node

Ian Dees ian.dees at gmail.com
Wed Sep 16 14:10:23 BST 2009


On Wed, Sep 16, 2009 at 7:38 AM, Peter Körner <osm-lists at mazdermind.de>wrote:

> Okay, so how can we go on now.. I'm not a ruby man and I don't have a
> possibility to test all this.
>
> Atm. my fallback-plan is to wait until the Wikimedia-Guys finished setup
> of their copy of the osm-db (which will contain the history tables!) so
> I can fetch my data directly from the db.
>

It would seem to me that the first step would be to build up a history table
that allowed us to know which rev node was used by a way at some revision of
a way. This could be done using the timestamps on the nodes and ways as
discussed elsewhere, but more importantly, it only needs to be done once.
Once we have this info, the way history call could include a node version
number along with a ref:

<way id=...>
   <nd ref="..." rev="1" />
   <nd ref="..." rev="3" />
   <nd ref="..." rev="1" />
</way>

... etc.


>
> I'm sure some months will pass by until this will happen and it would be
> sad I had to stop working until than :)
>
> Another thing that came into my mind was that we also should have an
> versioned GET /api/0.6/[way|relation]/#id/full call (I think this is
> what Ian requested, is it?)
>

With the above per-node rev attribute, it would be trivial* to populate a
full-history call.


>
> Any one volunteering to work on this?
>
>
I think it would be interesting... if someone helped me populate the initial
table based on timestamp in a way that wouldn't take years of CPU time.
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