Re: Sixth normal form

"paul c" <toledobythesea_at_oohay.ac> wrote in message news:%CNxi.70306$fJ5.3346_at_pd7urf1no...
> JOG wrote:
>> ...
>> Does anyone else understand any of this? ...
>
> It strikes me as absurdly technocratic, no apparent value, ie. for me the
> answer is no. I don't see any value in theory for its own sake unless you
> can say or guess at *some* point along the way what the "sake" is.

[snip]

No apparent value.... I gave an example before, but perhaps it was a bit too complicated. Suppose that you have a 5NF relation schema,

employee {emp#, last, first, ssn, payrate} where emp# is the key, last is the last name, and first is the first name, ssn is the social security account number and payrate is the hourly pay rate.

Now split it into the family of 6NF schemata,

emplast {emp#, last}
empfirst {emp#, first}
empssn {emp#, ssn}
emppayrate {emp#, payrate}

Wouldn't it be a bit strange for an employee to have a first name but not a last name? How about a pay rate without a social security account number? Under the domain closure assumption, if there is a value for emp#, then there is an employee with that employee number. For example, if there is a tuple {emp#:152, first:Brian} in empfirst, then there is an employee with employee number 152, and that employee has the first name, Brian. Under the closed world assumption, the absence of a tuple with employee number 152 in emplast indicates that the employee with employee number 152 has no last name. So how can you determine how much to pay him without a pay rate?How can you produce a check to pay him without a last name? How can you report to the government how much he was paid without a social security account number. If you can't pay him, then is he really an employee?

I now ask what is wrong with exploring why this can happen? Is this really theory for theory's sake? In order to find a correct solution, isn't it necessary to find the root cause?

I could be wrong, but I think I may have found the root cause. I offered it up here in this forum--the database theory newsgroup. If you don't understand what I'm trying to say, then please ask for clarification. If you see a problem with my argument, or even better, if you can prove that I'm wrong, then by all means do it: I'm not afraid to be wrong and would prefer to be corrected so I don't waste any more time on it.

> When the foundation is nothing more than mysticism, arbitrary vocabulary
> and name dropping, any result no matter how ostensibly it appears to be
> reasoned is likely to be up for grabs.

Are you saying the foundation of the relational model is mysticism? The whole notion of keys is semantic in nature: does that mean that the model is based upon mysticism? The entirety of normalization theory is semantically oriented, does that mean that it is all founded upon mysticism?

[snip] Received on Sun Aug 19 2007 - 14:43:30 CEST