Re: The relational model is a wrong theory

vldm10 wrote:

> Dana utorak, 8. listopada 2019. u 20:14:05 UTC+2, korisnik James K. Lowden napisao je:
>> On Mon, 7 Oct 2019 08:38:52 -0700 (PDT)
>> vldm10 <vldm10_at_yahoo.com> wrote:
>>
>> > A man named John Smith had black hair in 2010. In 2019, his hair was
>> > white. According to Codd's Relational model, these are two different
>> > people.
>>
>> I would like to think you're being provocative just to breath some life
>> into c.d.t. You don't truly believe what you wrote, right?
>
>>
>> Codd refers to the phenomenon of
>> "changing over time" in his 1970 paper.
>
> I can tell you that my grandmother said the same thing as you quoted E. Codd.
> But she's certainly older than Codd, so the priority for that idea
> belongs to her.

You have just illustrated why a set of values has no intrinsic meaning. The intended meaning can be interpreted successfully only with respect to the agreed predicate that everyone shares. The RM takes this as given.

I would like to think you did it deliberately, in which case, neatly done sir. Unfortunately it doesn't illustrate the claim you are making in the subject heading so it is probably an accident.

Roy

PS: I second James' gratitude to you for reviving c.d.t. Just try not to gnaw on too many imaginary bones. Received on Fri Oct 11 2019 - 15:00:33 CEST