A Simple Guide to Five Normal Forms in Relational Database Theory

I do a lot of interviews for software developers, and I ask a very simple database normalization question that close to half of the candidates miss completely. Something like: "You're tracking doctors, hospitals, and patients. Doctors can see multiple patients, and doctors can staff multiple hospitals". All I'm looking for you to say is that you'd put junction tables between the main entities. It's so, so crucial that developers understand the basics of database design, and normalization is a huge…

My biggest pet peeve in the world of data storage is that the most powerful ideas from relational data theory are still mostly locked up in books and papers, and most programmers who think they know what "relational" means aren't aware of the full picture. The people who did all the pioneering work on the subject (mostly E.F. Codd and Chris Date) seem to have made several blunders in trying to popularize their ideas. For example, one of Date's later…