1. When you start designing your database. It's implicit. It's only a process of reshuffling if you come to a bad designed database. 2. ? 3. You have a table (relation) with Instructors for their rows ...
As one works through the normal forms, be it a journey to the placid shores of third normal, or the more arid climes of Boyce-Codd normal form, or even the cloudy peaks of fourth normal and beyond—and ...