Re: In an RDBMS, what does "Data" mean?

"Anthony W. Youngman" <wol_at_thewolery.demon.co.uk> wrote:

>In message <mn6qb0p2dccituo6m3iklt5j04rml4hjg9_at_4ax.com>, Gene Wirchenko
><genew_at_mail.ocis.net> writes
>>"Anthony W. Youngman" <wol_at_thewolery.demon.co.uk> wrote:
>>
>>[snip]
>>
>>>As for Gene, I agree we need a theory, and actually, I think relational
>>>theory is a great theory. Unfortunately it is a theory about a - call it
>>>abstract, call it imaginary, they're the same thing - concept called
>>>"data" that does not seem to have any basis in the real world.
>>
>> That is not surprising since data is abstract.
>
>Well, is "mass" abstract? Or "energy"?

     No, but data is.

[snip]

>> No, the mess was smaller. The new theory was a better theory.
>
>Basically, Kepler corrected Copernicus' axiom that "orbit == circle"

     Yup.

>> Newton's is pretty good and will work for everyday situations
>>fine. Einstein's refines Newton's to cover yet more cases.
>
>More improvements here :-) The mathematical definition is steadily
>getting closer to the metaphysical reality ...
>>
>> The world is nearly flat. The variation from that is a small
>>fraction of an inch per mile. If you are dividing your backyard into
>>plots for gardening, you are safe assuming that the world is flat.
>>When you hit the big time, a different theory is needed. Before then,
>>it is more complicated than you need.
>
>But it doesn't make it correct ...

     It makes it correct *enough* for the simple case. And, of course, using the simpler form does introduce the possibility of scaling problems later.

     Einstein's might not be the ultimate either, but that is not going to stop people from dividing up their backyards into plots for gardening.

[snip]

>> A database models relevant portions of the Real World. What does
>>relevant mean? Of interest to someone.
>>
>>>And as I said before, it we have no idea if it's the correct theory, why
>>>are we using it? Dawn was going on about faith. Do you have faith in
>>
>> It is the closest that we know of.
>
>It is the closest that YOU know of.

     Produce your theory, please, in comparable rigourousness to Codd's.

>>>business analysts to get the analysis correct, or would you rather have
>>>a formal, REVERSIBLE and PROVABLE (or testable, falsifiable, scientific,
>>>whatever term you want to use) logical theory to do it for you?
>>
>> I would rather have the theory, but in its absence, I will use
>>what I have.
>>
>Great. So why aren't you prepared to question the accuracy of the axiom
>that "data comes in tuples".
>
>Yes, relational data DOES come in tuples - because that's what the
>definition says.

     You have just answered your question for me.

>But if you can't come up with some formal way of converting between
>"real-world-data" and "relational tuples", then surely you have to come
>to the conclusion (which my and Dawn's EXPERIENCE has forced us to) that
>your tuple is equivalent to a Copernican circle - it may be close to
>reality but there's something seriously wrong somewhere that needs
>correcting - and it CAN'T be done WITHIN the theory, because the fault
>lies in the theory-to-reality map.

     So maybe we need a second theory that deals with something that Codd's does not. In the meantime, I will not throw out the baby with the bathwater, and people will keep dividing up backyards.

Sincerely,

Gene Wirchenko

Computerese Irregular Verb Conjugation:

     I have preferences.
     You have biases.
     He/She has prejudices.