Is it OK not to use a Primary Key When I don't Need one

Question

If I don\'t need a primary key should I not add one to the database?

Answer 1

Yes, a table should ALWAYS have a primary key... unless you don't need to uniquely identify the records in it. (I like to make absolute statements and immediately contradict them)

When would you not need to uniquely identify the records in a table? Almost never. I have done this before though for things like audit log tables. Data that won't be updated or deleted, and wont be constrained in any way. Essentially structured logging.