Regarding Recovery Planning, must the snapshots for the code base and the db be done at the same time? Let me elaborate.

I changed the theme of a development site to one I had downloaded. Apparently, that theme started causing problems. Shortly after, I was not able to access the Admin menu/pages (I was getting an internal server error [error 500]).

When creating/restoring backups, what are the guidelines? Most importantly, how dependent are the code base and the database itself?