General Multi-DB Questions – Newbie Warning

These are some general Newbie Multi-DB Questions I’ve had and searching the forum seems to be confusing me more, so if there is a clear answer I have missed feel free just to give me the link.

1. What is the best way to go about backing up your Multi-DB install? I generally use Backup Buddy but it seems to only grab the first database so not sure that would still be a solution.

2. If you need to locate a particular site in the databases for some reason how would you do that?

3. How do you know when to add something to the add_global_table?