SQL Antipatterns

Appendix 1Rules of Normalization

Young man, in mathematics you don’t understand things. You just get used to them.

John von Neumann

Relational database design isn’t arbitrary or mysterious. You can use a number of well-defined rules to design a data storage strategy that avoids redundancy and helps make your application mistake-proof, like the poka-yoke ideas mentioned earlier in this book. You’ve probably heard other metaphors for the same idea, such as defensive design or fail early.

The rules of normalization aren’t complicated, but they are subtle. Developers often misunderstand how they work, perhaps because they expect the rules to be harder than they are.

Another possibility is that people are turned off by having to follow rules ...