Database Normalization Guides

[ToddW]

Lately I have been spending a lot of time reading about DB normalization and the different form #s. There's a lot to grasp especialy when you get out of the basics and into large amounts of data! I found the following articles very helpful for grasping DB Normalization.


This briefly describes the normalization form 1-4
http://databases.about.com/od/specif...malization.htm

NF2 Sample/Help
http://databases.about.com/od/specif...ucts/a/2nf.htm

NF3 Sample/Help
http://databases.about.com/od/admini.../bldef_3nf.htm

This goes from 1NF --> 6NF (Well, kind of 6) with examples.
http://www.answers.com/topic/database-normalization

[ToddW]

I can't edit my post but this is a good page of samples of how to move from one form to the next:

http://sandbox.mc.edu/~gwiggins/syll...-examples.html

[JamieJelly]

is it necessary to go beyond NF4? I was told back in school it was fine to stop here

[veridicus]

3 is the most common to try to achieve. It's a very practical level. 4 is difficult. 5 is generally considered an ideal that no one even tries to achieve. There's a big difference between academic ideals and practicality.

There's an old joke about a job interview question. A typical interview question for a software developer used to be "What is 3rd form normalization?". Of course the answer is, "It's between 2nd and 4th form normalization."

[ToddW]

Originally Posted by veridicus

3 is the most common to try to achieve. It's a very practical level. 4 is difficult. 5 is generally considered an ideal that no one even tries to achieve. There's a big difference between academic ideals and practicality.

There's an old joke about a job interview question. A typical interview question for a software developer used to be "What is 3rd form normalization?". Of course the answer is, "It's between 2nd and 4th form normalization."

Yeah, most places I have read and other people in the industry say 3 is the most common.