[Imports] Import of Flemish Government data (building footprints and addresses)

[Christoph Hormann]

On Monday 29 October 2018, Kevin Kenny wrote:
> [...]
>
> In both cases, it's to be able easily to check, when a new version of
> the external data comes out, whether anything has happened to a
> particular object. I retrieve it by its ID, then test whether the
> last modifying user was me. (Yes, I start with multipolygons, and
> recurse into ways and points.) If I can't find an object with the ID,
> or if another mapper has modified the object, then I know that I have
> to treat the state of the object as unknown and conflate by hand.

For this purpose it is completely unnecessary to bother the OSM 
community with external IDs.  If you want to check if the data has been 
unchanged since you added it then do exactly that - check if there are 
any newer versions of the objects that have originally been added in 
the import.

I don't really understand why this discussion is coming up again and 
again with imports here.  To me this very much looks like a 'lazy 
programmer' attitude - having an ID available probably seems the most 
conventient way to identify the object.  But think about this for a 
moment - you want to bother the OSM community with the burden of 
dealing with these IDs forever just to make it a tiny bit easier for a 
programmer to possibly in the future write code to identify what 
features from the import have not been changed since they were added.

Note i completely get that many programmers are unfamiliar with the OSM 
concepts of changesets, object versions etc. and for them it would 
indeed be more convenient not to have to deal with that and instead 
retrofit OSM to what they are used to.  But that is not something OSM 
should accept.

-- 
Christoph Hormann
http://www.imagico.de/