I've noticed that as you create and delete records, id's that are no longer being used don't seem to get used again. Is this supposed to happen? Is there a way to choose an id that is not being used for a new record? (because the record that had previously used an id has been destroyed)
This is pretty standard behavior for a database and is not specific to Rails.
Oh! Didn't know that. Thanks. So that never really ever causes trouble then? id's don't ever get rearranged by the db?
Oh! Didn't know that. Thanks. So that never really ever causes trouble then?
It can if the integer wraps around and starts at 1 again. But that's usually a long way off 
id's don't ever get rearranged by the db?
No.
All very good to know! I'm not deeply database knowledgeable as you can tell. Thanks a lot!