I have never seen a properly denormalized table. In practice you will get a "historically grown" system way to often and doing anything like that will break things.
The whole article seems to be quite academic from my personal experience a textbook normalized database is slow beyond belief (i did exactly that once and we had to revert it back).
>I have never seen a properly denormalized table
Do you mean normalized? There's no such thing as "properly" denormalized, anything that is not normal is denormalized.
>The whole article seems to be quite academic from my personal experience a textbook normalized database is slow beyond belief (i did exactly that once and we had to revert it back).
I've seen lots of people say that, but then consistently found those same people don't actually know what the normalization rules are, and all they did was create a different denormalized database that happened to have poor performance for the queries they were using.