Re: Is relational theory irrelevant? (was Re: Dreaming About Redesigning SQL)

brennie_at_dcsi.net.au (Bruce) wrote in message news:<64ea97cf.0311090213.38942cc_at_posting.google.com>...
> There is an example in this news group from some time ago, where
> someone used the D4 language (based on Date and Darwen, by Alphora in
> their Dataphor product) to build a query directly from the user
> requested query. It was beautiful, <....>
> The SQL formulation, I believe, would be considerably longer
> and much obtuse. If I recall correctly, it arose out of an argument
> over whether SQL was/wasn't truly relational. A one page formaulation
> including the design of the database.

The reference, please. I find it hard to believe that differences in NULL treatment and Multiset Semantics can result in considerable gap in expressibility betwen Relational Algebra/D4 and SQL. (What else can be the source of D4 superiority?). SQL had grown to embrace every feature in the world, so that I would think that it's easy to make the opposite case where 2 line SQL query with analytical extensions would be translated into a page of D4 code. It might be that the ANSII comittee and vendors didn't really gave much thought to certain SQL features, and language orthogonality was certainly not their priority, but we can't say that SQL lacks expressibility. Received on Sun Nov 09 2003 - 20:20:50 CET