4/14/2026 at 5:59:31 PM
In a roundabout way this article captures well why I don't really like thinking in terms of "normal forms", especially as a numbered list like that. The key insights are really 1. Avoid redundancy and 2. This may involve synthesizing relationships that don't immediately obviously exist from a human perspective. Both of those can be expanded on at quite some length, but I never found much value in the supposedly-blessed intermediate points represented by the nominally numbered "forms". I don't find them useful either for thinking about the problem or for communicating about it.Someone, somewhere writing down a list and that list being blessed with the imprimatur of Academic Approval (TM) doesn't mean it is actually useful... sometimes it just means that it made it easy to write multiple choice test questions. (e.g., "What does Layer 2 of the OSI network model represent? A: ... B: ... C: ... D: ..." to which the most appropriate real-world answer is "Who cares?")
by jerf
4/14/2026 at 6:07:59 PM
> Someone, somewhere writing down a list and that list being blessed with the imprimatur of Academic Approval (TM)One problem is that normal forms are underspecified even by the academy.
E.g., Millist W. Vincent "A corrected 5NF definition for relational database design" (1997) (!) shows that the traditional definition of 5NF was deficient. 5NF was introduced in 1979 (I was one year old then).
2NF and 3NF should basically be merged into BCNF, if I understand correctly, and treated like a general case (as per Darwen).
Also, the numeric sequence is not very useful because there are at least four non-numeric forms (https://andreipall.github.io/sql/database-normalization/).
Also, personally I think that 6NF should be foundational, but that's a separate matter.
by petalmind
4/14/2026 at 6:14:19 PM
"1979 (I was one year old then)."Well, we are roughly the same age then. Our is a cynical generation.
"One problem is that normal forms are underspecified even by the academy."
The cynic in me would say they were doing their job by the example I gave, which is just to provide easy test answers, after which there wasn't much reason to iterate on them. I imagine waiving around normalization forms was a good gig for consultants in the 1980 but I bet even then the real practitioners had a skeptical, arm's length relationship with them.
by jerf
4/14/2026 at 10:29:52 PM
The levels do the most important thing in computer science, give discrete and meaningful levels to talk/argue about at the watercolourby awesome_dude
4/14/2026 at 6:40:53 PM
Why shouldn’t we care about layer 2? You can do really fun and interesting things at the MAC layer.by wolttam
4/14/2026 at 7:18:43 PM
You can do what you do at the MAC layer without any regard for whether or not it is "OSI layer 2", or whether your MAC layer "cheats" and has features that extend into layers 1, or 3, or any other layer. Failing to implement something useful because "that's not what OSI layer 2 is and this is data layer 2 and the OSI model says not to do that" is silly.To stay on the main topic, same for the "normalization forms". Do what your database needs.
The concepts are just attractive nuisances. They are more likely to hurt someone than to help them.
by jerf