What's the best practice for primary keys in tables?

Question

When designing tables, I\'ve developed a habit of having one column that is unique and that I make the primary key. This is achieved in three ways depending on requirements

Answer 1

We do a lot of joins and composite primary keys have just become a performance hog. A simple int or long takes care of many problems even though you are introducing a second candidate key, but it's a lot easier and more understandable to join on one field versus three.