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

From: Anthony W. Youngman <wol_at_thewolery.demon.co.uk>
Date: Fri, 18 Jun 2004 19:19:34 +0100
Message-ID: <YabRN3J2Iz0AFwou_at_thewolery.demon.co.uk>


In message <40ccc506$0$48920$e4fe514c_at_news.xs4all.nl>, mAsterdam <mAsterdam_at_vrijdag.org> writes
>>>R 'loses the ability to view the data' from within M and that
>>>would somehow mean M is *more* expressive?
>>>The only way I could make sense out of that is
>>>if the (appearant) excess expressions in R could
>>>*not* be relevant to a solution.
>>>
>>>Do you have an indication as to what those excess expressions are?
>> they tend to be data that were collected and stored in the M
>>solution and
>> designed out (deemed unimportant to retain) for the R solution.
>
>Just to get it straight: These 'designed out' data *can*
>be represented in R (inferred from the R translation of the M
>solution),
>but they are *not* represented in R because of the different design
>process (ispired by the nature of M cq. R)?

Yes. Because M has retained metadata (which it can express as data in R).

But R may not be able to express that in M because the analyst didn't view the metadata as important.

And even where R expresses an M-like view of the data, it contains less INFORMATION, because R is unaware that it is expressing metadata.

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 18 2004 - 20:19:34 CEST

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