Re: 1 NF

"paul c" <toledobythesea_at_oohay.ac> wrote in message news:s2kGh.1209871$5R2.691129_at_pd7urf3no...
> I'm now wondering if my previous comment about throwing the term "1NF"
> in the garbage was a bit too shallow (and, I hate to say, whether Celko
> was on a useful track, even though as usual he didn't give pertinent
> reasons). IIRC, in another thread Bob B mused about implicit
> conversions of singleton sets which also got me to wondering and made me
> start to look at TTM's suggestions about inheritance for the first time.
>
> Codd being the terse guy he was, I find it easy to fall into the trap of
> reacting to his words as if he meant them to be all-inclusive. For
> example in the 1970 paper he said "A relation whose domains are all
> simple can be represented in storage by a two-dimensional
> column-homogeneous array of the kind discussed above." I don't think
> this means that a relation is necessarily two-dimensional. He continues
> with "...the possibility of eliminating nonsimple domains appears worth
> investigating ... There is, in fact, a very simple elimination
> procedure, which we shall call normalization." He gives some reasons
> such as avoiding pointers and then says "If the user’s relational model
> is set up in normal form, names of items of data in the data bank can
> take a simpler form than would otherwise be the case."
>

I've stayed away from this discussion, because its title suggests that it's a troll magnet.
But the above is worth commenting on.

I find Codd to be refreshingly concise, rather than terse. In the above quote is is NOT asserting that a relation "is two-dimensional". He IS asserting that (a certain kind of) relation can be represented by a two dimensional data structure. The difference between what something "is", and what it "can be represented by" pervades all of data management. The careful reader is expected to pick up on this distinction, without further verbiage.

The whole paper, especially this extract, is dedicated not only to the proposition that a relational data base system is possible, but that one is feasible as well. The entire discussion of "normalization" in this context, is devoted to the assertion that a rule requiring this kind of normalization in a given database does not thereby limit the expressive power of the data in the database, and very likely makes the construction of the first relational database system easier.

The tone is so different from what one encounters here in c.d.t. Received on Sat Mar 03 2007 - 21:35:05 CET