Re: Why is "group by" obligatory in SQL?

From: Cimode <cimode_at_hotmail.com>
Date: Fri, 24 Jul 2009 09:49:31 -0700 (PDT)
Message-ID: <85f8c072-7f28-40e8-a8f5-0b20c105d49b_at_l2g2000vba.googlegroups.com>


> I suspect that what a 'TRDBMS' is, isn't yet fully known.  Lots of open
> questions, here're just a few:
>
> - Codd espoused logical data independence, yet by assuming some
> relations couldn't be updated in certain ways, he allowed a kind of
> contradiction, or at least a kind of dead-end.
>
> - there is normalization theory to do with avoiding redundancy, but
> nothing comparable to do with avoiding ambiguity.
>
> - where is the constraint theory?  will normalization turn out to be
> just a small part of this?
>
> - is the ultimate interface a program that it is in effect a relation?
> - .

To this list I could add a list of hundreds of questions such as:

> What are the fundamental limitations of binary systems one should take into considerations when representing and operating relations.
> How to effectively represent disjointness between two sets

to name a few... Received on Fri Jul 24 2009 - 18:49:31 CEST

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