Named Mistakes and Questionable Practices

Has anybody here made a list of canonical mistakes[1] that DB practitioners make?

One example mistake is the One True Lookup Table aka the Entity-Attribute-Value table, as in this article: <http://www.dbazine.com/ofinterest/oi-articles/celko22>. Doubtless people have run across others. Ideally, such references would:

• Name the mistake,
• Describe the mistake's implementation, and
• Show how and under what circumstances it's a mistake, as the above article does.

Thanks in advance for any hints, tips, or pointers :)

Cheers,
D

[1] Let's exclude, for the purposes of this discussion, the idea that SQL itself is a giant mistake and that we should now be using VaporWareTransRelationalDBMS™--vague, questionable patents filed--which will eventually be a product some day. We can say that that horse has already been beaten well enough and is already deceased, if it makes people happier.

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