I found this great post at Lorelle’s blog about how to do terrifying scary dangerous stuff to your WordPress database.
Like if you want to do a massive search and replace on stuff. Or bulk-change all the posts’ comment status. Or rename the database. Lorelle makes this comment at the start of the post:
There are times when you must enter the WordPress MySQL database to search and replace some content. If you don’t have to do this, then DO NOT DO THIS. If you have to do this, then your head should be examined carefully, opened up and inspected for programming errors, and then you may proceed with due and dilligent care.
It sort of sets the tone, but really, tinkering with the internal workings of your blog while it’s live and running, isn’t so big a deal. Just don’t sneeze or spill pizza into its brain, and things should be ok. Do make a backup or two though, before you begin…