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

From: Anthony W. Youngman <wol_at_thewolery.demon.co.uk>
Date: Fri, 4 Jun 2004 00:56:35 +0100
Message-ID: <vChcrhIzq7vAFw2B_at_thewolery.demon.co.uk>


In message <J78vc.9363$wI4.1210539_at_wards.force9.net>, Paul <paul_at_test.com> writes
>Dawn M. Wolthuis wrote:
>>> To go back to your favourite analogy (apologies everyone), it is
>>> like saying that algebra was responsible for the shortcomings of
>>> Newton's model of planetary motion. But it wasn't the algebra that
>>> "got it wrong", it was Newton's application of it.
>> Agreed!
>>
>>> The relational model corresponds to algebra in this analogy,
>> YES!
>>
>>> not to Newton's model of the solar system - that corresponds to a
>>> specific database design.
>> wrong -- that corresponds to the use of relational theory at all
>> while working with computers. It is not the specific implementation
>> only that could be wrong -- it is the use of this theory AT ALL
>> related to "data processing" that COULD BE wrong (I don't think it is
>> entirely irrelevant, but there is nothing that proves its relevance
>> except where "the proof is in the pudding" -- scientific observation,
>> for example).
>
>No, I think in this analogy Newton's model does correspond to a specific
>database design. The possibility that the relational theory itself is
>wrong corresponds to the possibility that algebra is wrong.

Exactly.

And Newton's algebra is NOT wrong. It's just that the axioms (on which he based his algebra) don't match reality. And that cannot be proved from WITHIN the algebra.

So you cannot prove that relational theory is right or wrong from WITHIN the theory.
>
>>> Einstein didn't invent a better algebra, he designed a better model
>>> using the SAME algebra - like a later designer designing a better
>>>payroll database, but still using the same RDBMS.
>> No, like a later database theorist designing a graphical theory or a
>>functional theory that is better than the relational theory before
>> it.
>
>I think that would correspond to Einstein inventing a better algebra
>for his model. I belive tensor algebra was actually used for
>relativistic mechanics, but it's not really an improvement to standard
>algebra, just a different example of it.
>
>I think you're mistaking the theory of (algebra, relational databases,
>logic) itself with theories that can be developed in them, for example
>(Newtonian mechanics, payroll database, relativistic mechanics). We've
>got two levels of theories here.
>

And we also have experiments to show that the axioms do (or don't) accurately describe reality. Einstein showed that Newton's axioms didn't describe reality, and replaced them by new axioms that did a better job. He didn't alter Newton's algebra at all - indeed, he used exactly the same algebra ...

Cheers,
Wol

-- 
Anthony W. Youngman - wol at thewolery dot demon dot co dot uk
HEX wondered how much he should tell the Wizards. He felt it would not be a
good idea to burden them with too much input. Hex always thought of his reports
as Lies-to-People.
The Science of Discworld : (c) Terry Pratchett 1999
Received on Fri Jun 04 2004 - 01:56:35 CEST

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