This thread worries me...
I never paused to ask myself what would happen to my +1000 books if the database got corrupted. I would never start again fine tuning everything if it happened to me!
So I just started making backups - metadata.db is just under 4MB, not a big deal.
But - suppose I had to restore it due to corruption, and in the meantime I've added some books to my library, how does it work? I will find myself just with the new books missing (not a big deal) or with metadata.db completely unable to make sense of my library?