Re: Do Data Models Need to built on a Mathematical Concept?

Neo wrote:

>>I don't think anybody is claiming that the Relational Model
>>(as we know it now) is the final answer.
>>
>>
>
>IMO, Mr. Cozianu seems to imply that the final model for representing
>data is the current relational data model. Although the relational
>data model is sufficient for the majority of applications (currently),
>it is not sufficient for all applications. I am certain he is wrong on
>this account.
>
I meant that I don't think that Mr. Cozianu claims that he can see 200 years into the future
and predict what kinds of database systems (if any!) we will the have at our disposal. It just
looks currently now like the relational model has the most promise.  Compare it to Newton
and his theory circa 1670: If you had lived then and told Newton that, well, you know, some
day your theories will be superseded, you would have been correct, sort of, but your
observation would not have been very usefull at that time.

>>However, what is important to understand is that the whole body
>>of modern mathematics is based on the "relational model", in a sense.
>>
>>
>
>If by "relational model" you simply mean that things can have
>relationships, then I would agree.
>
No, no. *Relations*, or actually set theory.

>If by "relational model" you mean Codd's "relational data model" where
>each tuple in a relation has to be of the same degree and each value
>of a domain has the same type, then I would disagree with the use of
>the quantifier "whole body". The arbitrary restrictions in Codd's
>"relational data model" prevent it from being the basis for the WHOLE
>body of useful mathematics that man can invent. The arbitrary
>restrictions make the implmentation easier but also limited its
>flexibility.
>
This inflexibility is the basis for practically all modern mathematics, believe it or not.

>>As for using the human brain as a model:
>>There is a theory called Bayesian Networks that handles
>>fuzzy reasoning well (it is actually based on a statistical model).
>>
>>
>
>By the human brain model, I meant only that area related to
>representing things. I know for certain that it is not restricted by
>data type and the need to have same number of attributes for each
>thing.
>
We don't really know very much about how knowledge is represented in the human brain.
However, getting the data out of it does require quite a lot of *software* ;-)

regards,
Lauri Pietarinen Received on Sat May 03 2003 - 20:35:29 CEST