Re: Is it possible to build a purely relational database on top of SQL?

"Paul Vernon" <paul.vernon_at_ukk.ibmm.comm> skrev i en meddelelse news:ccbbsp$1iqq$1_at_gazette.almaden.ibm.com...
> "Ralph Becket" <rafe_at_cs.mu.oz.au> wrote in message
> news:3638acfd.0407050029.5424e360_at_posting.google.com...
> > Please forgive me if this question is naive/asked every other
> > week (to date I've been unable to find an answer on Google.)
> >
> > My question: is there any reason why a purely relational database
> > interface, in the "Third Manifesto" sense of, say, Tutorial D,
> > could not be built on top of any existing commercial SQL DBMS?
>
> It's possible (depending, I guess, on how pure you are about purity), as
> shown rather neatly by Alphora.
>
> Sniping quotes from http://www.alphora.com/tiern.asp?ID=HIGHLEVEL
> "The Alphora Dataphor Data Access Engine (DAE), part of the Dataphor
> toolset, is a <i>truly</i> relational database system."
>
> "The DAE, however, has a "virtual" storage engine that can interface
> with data from nearly any data source.This open-ended architecture allows
> the DAE to be placed "on top" of existing DBMSs such as Oracle, DB2, and
SQL
> Server"
>
> Some other quotes to spice things up
> "Over time, SQL deficiencies have impacted the industry deeply, even
> creating entire markets for products that work around the problems."
>
> "The Relational Model is the "mathematics of data" and SQL is simply a
> poor calculator."
>
> "D4 is not intended to be proprietary, but to serve as an open
standard
> to replace SQL."
>
>
> > That is, could one build a true RDBMS without having to rewrite
> > everything from scratch?
>
> On the other hand, one might argue that in fact it is technically more
> difficult to build a complete D like environment ontop of a SQL RDBMS,
> rather than write a D DBMS from scratch. However, it' probably more
> difficult to get the latter to market.
>
> Regards
> Paul Vernon
> Business Intelligence, IBM Global Services
>
>

How far has Alphora come in terms of conformance with D? And if they are 100% conformant, do they allow SQL access to the same data? I believe it could give some problems querying a database with user defined datatypes in it as well as supporting inheritance the way D uses that term.

Kind regards
Peter Received on Mon Jul 05 2004 - 15:58:32 CEST