Hi Kovid,
we had some short discussion about one year ago (
this thread) about allowing the main editing work might be performed on the "work" computer and at the same time the content server process (and possibly some cron-driven content fetcher jobs) might be running on a seperate server.
As far as I remember, we were pretty much agreed on that this would require a seperate database for calibre (MySQL, Postgres, whatever you want). You had mentioned that you want to look at this after 0.7 is started

Is the database refactoring part still on your time table?
Regards,
Hakan