[OSM-talk] Tagging the source

[Pieren]

The tag 'source' on the changeset has some pros and cons:
Pros:
- size in database
- works only if the changeset comes from a single source
Cons:
- impossible to modify after changeset is closed
- attribution lost in data extracts, planet (separate file for changesets)
- doesn't allow more than one source per changeset
- rebuild one element history is not trivial (one API call per element
+ one per changeset multiplied by amount of versions)

The tag 'source' on elements:
Pros:
- support multiple sources during edit session
- attribution present in planet, extracts
- can be modified at any time
- retrieve one element history is easy (one API call)
Cons:
- size in database
- works fine only for small edit sessions (or imports)

Pieren