Re: (OT)Dynamic inheritance (was: Object support in the relational model??)

>
> Date & Darwen's programming model separates data and action fairly
strictly,
> yet still provides all the important types of polymorphism. This idea has
> really started to appeal to me -- the common OO inheritance models seem to
> bundle too many orthogonal concepts together. I'd like to see what a
> language would turn out like if it started from D&D's Tutorial D and added
> good module/package features, like Modula-2 or Ada. I suspect that it
would
> be very flexible.
>

My only complaint about this is that it is not happening fast enough!! We developers who really want a rigorous implementation of the relational model, along with object-relational capabilities should be doing everything possible to make this happen:

1. To date there has only been one attempt at an implementation of Tutorial D, which is a commercial project, available only on Windows servers: Dataphor, at www.alphora.com (see http://www.pgro.uk7.net/x_trdbms_impl.htm).
2. But, there is a SourceForge "placeholder" for discussion of a project to create an open implementation of TutorialD, though: http://sourceforge.net/projects/tutoriald/ Let's all provide as much support for this as possible.
3. If there is any existing database that lends itself to these endeavors, it would be PostgreSQL (www.postgresql.org). In the past, Date, Darwen, et all... have said that the Ingres database (on which PostgreSQL was based), was the only commercial database he saw that had any potential to be a true RDBMS. At the time, Ingres used its own query language called QUEL, which apparently adhered much closer to the relational model than SQL. (But, of course, pure survival dictated that Postgres had to support SQL, thus it became PostgreSQL.)

See
http://searchdatabase.techtarget.com/tip/1,289483,sid13_gci788645,00.html and
http://lists.xml.org/archives/xml-dev/200111/msg00338.html

4. My point is that SQL flourished because of industry (and developer) demand. As Date, Darwen and Pascal say, the only way we will get a better relational database is if we provide enough demand (and support) that it becomes worth the while of the industry developers, and hopefully the open source guys such as Postgres as well.

Rick Morris Received on Fri May 31 2002 - 13:51:01 CDT