Re: Dreaming About Redesigning SQL

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От dwolt@iserv.net (Dawn M. Wolthuis)
Тема Re: Dreaming About Redesigning SQL
Дата
Msg-id 6db906b2.0310100722.e5560a0@posting.google.com
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Ответ на Re: Dreaming About Redesigning SQL  (Christopher Browne <cbbrowne@acm.org>)
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While I definitely agree that the mathematics of the data persistence
mechanism is not as important to me as whether it works or not, as a
former mathematician, I have done a little study related to the
mathematics of non-relational approaches, such as PICK (the one both
Wol and I have been know to advocate on behalf of).

These models tend to start with language rather than mathematics.  So,
what started out as my attempt to show such things as the fact that a
PICK file is more like a mathematical RELATION than an RDBMS table, I
ended up studying the mathematics of language for a short time - one
can see that the mathematics of language, which is what we are storing
when working with text-based objects, is much more complex than simple
relations.

By the way, in case you are wondering how PICK files are more like
mathematical relations -- they do have a numbered position for each
domain (in other words, there is a location for each column within a
row as there is a location in a PICK ITEM/RECORD); they do not by
default request a constraint on the length of values in a given domain
(a quite unnecessary database constraint); and they permit relations
as elements within a relation -- there is no mathematical requirement
that a relation be in first normal form, for example.

I do tire of the thought that a database premised on the relational
model is somehow more mathematically accurate than those premised on a
language model.  PICK, like XML, was used to make it easy to think
about storing and retrieving text.  If you set aside the need for
storing other objects for now and focus on text-based data
persistence, it is simply a means to persist propositions. If one were
to normalize your sentences before you said them, you might guess that
people would have a harder time figuring out what you were saying. 
Similarly, normalizing data before persisting it tends to make it
difficult to retrieve the original propositions, reconstructing
language from normalized data.

It's time to move on from the relational model -- it was a good
academic exercise, but has not proven a very agile means for
persisting and retrieving propositions, methinks.  smiles.  --dawn

"Anthony W. Youngman" <thewolery@nospam.demon.co.uk> wrote in message news:<xTDLP1CFRIg$Ewjw@thewolery.demon.co.uk>...
> In article <3F7F8E1A.474@ix.netcom.com>, Lee Fesperman
> <firstsql@ix.netcom.com> writes
> >If you don't care for mathematical principles, there's always ad-hoc database 
> >models. 
> >Check out Pick, OO and XML databases. They're interested in what works and 
> >ignore 
> >elegance and mathematical principles.
> 
> Mathematical principles? You mean like Euclidean Geometry and Newtonian
> Mechanics? They're perfectly solid, good, mathematically correct. Shame
> they don't actually WORK all the time in the real world.
> 
> That's what I feel about relational, too ...
> 
> Cheers,
> Wol


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