potential performance impact because we fetch every item for each
relation, let's hope the caching fixes that.
notes from randa:
- Get mimetype id as part of relationquery.
- Lookup mimetype name in local cache.
-> at them moment the mimtype as string is used as argument and also transfered
-> till what point i should use the id, and where to transform to the name?
- Port to new protocol.
-> should be done