Re: Foreign superkey support

"Marshall" <marshall.spight_at_gmail.com> wrote in message news:1155134332.345985.119920_at_m73g2000cwd.googlegroups.com...
> David Cressey wrote:
> > "Marshall" <marshall.spight_at_gmail.com> wrote in message
> > news:1155100237.103860.180160_at_h48g2000cwc.googlegroups.com...
> >
> > > In other words, there is a many-to-many relationship between
> > > constraints and relvars. (Or relations, if we are thinking in
> > > descriptive rather than prescriptive terms.) For example,
> > > we often speak of a foreign key constraint as belonging to
> > > one particular table, but it is equally a constraint on two tables.
> > > On one table it restricts inserts and on another table it restricts
> > > deletes. So we must necessarily classify it as a database
> > > constraint. But really, all constraints are all database constraints,
> > > although there may be some database constraints that only
> > > happen to be quantified over a single relvar.
> > >
> >
> > Here I am as Johnny one note, chiming in again.
>
> Dude, any time. I'm not a recent college graduate who believes
> he already knows everything he needs to :-) The Wisdom of
> the Elders is welcome.
>
>
> > And how did I come to know DSRI? DEC Rdb/VMS was DSRI compliant.
> > You knew I was going to come around to that, didn't you???
>
> I googled for Digital System Relational Interface and there wasn't
> much. Might you be able to find some on-line references?
>
>
> Marshall
>

The best overview of DSRI a came up with was this one:

http://www.ibphoenix.com/main.nfs?a=ibphoenix&s=1154547732:1787&page=vul_architecture

However, it doesn't address the DSRI standards with regard to metadata in system tables.

IIRC, some of DEC Rdb/VMS system tables and their columns were DSRI conformant, and some were product specific, and the naming conventions showed that distinction.

But I haven't found a good description yet. Received on Thu Aug 10 2006 - 13:34:44 CEST