Ok, so far so good. But now what do I do if I add more keywords to photos that are in buckets that have been burned to offline media? Do I re-burn an entire bucket, even if only some of the files within it have had keywords added? Is there some threshold?
Or do I rely on mirror backups of the mainline buckets to keep my metadata safe? Then it seems there's a gap between the online backup and the offline backup - if both should fail catestrophically and I only have the offline backup, I've lost any metadata added since the bucket was burned (which is controlled by shooting volume).
Backup your catalogue file regularly too. That's where you backup your incremental/current metadata.
A parallel question for the master/derivatives "branch" of buckets. You'll burn those off to CD/DVD once you've got enough in the bucket, but if you revisit and edit files that are in buckets that have been burned do you re-burn the bucket? Do you duplicate the file into the current bucket and only work on that one going forward?
Keep these buckets as originals, only writing metadata to them. Any edits go into derivatives buckets.