How do you determine how far to normalize a database?

Question

When creating a database structure, what are good guidelines to follow or good ways to determine how far a database should be normalized? Should you create an un-normalized

Answer 1

Having a normalized database will give you the most flexibility and the easiest maintenance. I always start with a normalized database and then un-normalize only when there is an real life problem that needs addressing.

I view this similarly to code performance i.e. write maintainable, flexible code and make compromises for performance when you know that there is a performance problem.