Nature never breaks her own laws.
—LEONARDO DA VINCI
I always advocate following proper database design techniques. As you’ve already learned, there are numerous reasons for doing so. But first and foremost, you should use a good design method to ensure the integrity of the database. I cannot overstate how important this is. You now know the consequences of improperly establishing data integrity, so following the rules is of paramount importance.
There are only two specific circumstances under which it is at all permissible to bend or break the rules of proper database design. ...