One thing I didn't like about Matrix: I had a single server with 3 or 4 other users. In a few months, the database ballooned to, like, 80GB. User-uploaded content, including text, was in the ballpark of 2 or 3GB. Is there any way to clear out the cache of data received from old servers, say, anything more than 2 weeks old, and re-retrieve it if needed?