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

"Bob Badour" <bbadour_at_golden.net> wrote in message news:<fsGdnRimJ8RxWDOiRVn-gQ_at_golden.net>...
> "Mikito Harakiri" <mikharakiri_at_yahoo.com> wrote in message
> news:bdf69bdf.0311091120.14065bc5_at_posting.google.com...
> > 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.
>
> Express a quota query.

select top 5 * from (

   select * from emp order by sal
)

What is the problem, besides "5*from" looking ugly? Received on Mon Nov 10 2003 - 05:59:28 CET