Re: separation of church and state?

From: paul c <>
Date: Sat, 06 Oct 2007 17:07:19 GMT
Message-ID: <bhPNi.6572$_K.3238_at_pd7urf3no>

David Cressey wrote:
> "paul c" ...
> It is a little doctrinaire. Oracle/Rdb (originially DEC Rdb/VMS) has
> always allowed ORDER BY in a view definition. No damage was done to the
> ability of the user to apply concepts of relational algebra to the task of
> getting useful work done. One could reference such a view inside another
> view, or in any other context where an unordered table would have been
> expected, and the results were logically equivalent to the result one would
> have obtained in the absence of the ORDER BY.
> Oracle RDBMS, by contrast, has always forbidden ORDER BY in view
> definitions. Other than satisfying some people's need for doctrinaire
> purity, the RDBMS users gained nothing by this restriction.
> I think you're extrapolating Date's remarks to a point that he might not
> agree with. A table with an index is still a table.
> BTW, the doctrinaire folks among us will insist that SQL does not have INDEX
> in the standard. But we all know that SQL databases use indexes to speed up
> queries. And many application programmers appreciate being told what
> indexes are present so that they can organize their queries for performance.
> The doctrinaire people will say that the programmers have no need to know
> index information, because it's not part of the logical model. In theory
> they are right. In practice, it helps to provide them with it.

I'm not sure it's a stretch. I feel fairly confident about resorting to   the Information Principle when asking if a result is correct according to an algebra. Admittedly, I lump aspects such as ordering and indexing as 'not applicable' when trying to apply the IP. If I may be allowed to discount those aspects for results, I don't see why I can't discount, ie., ignore them, for intermediate results. Received on Sat Oct 06 2007 - 19:07:19 CEST

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