Re: MV Keys

From: x <x_at_not-exists.org>
Date: Wed, 8 Mar 2006 10:34:50 +0200
Message-ID: <dum4vd$es4$1@emma.aioe.org>

"Marshall Spight" <marshall.spight_at_gmail.com> wrote in message news:1141787070.196520.53850_at_e56g2000cwe.googlegroups.com...
> David Cressey wrote:
> > "Marshall Spight" <marshall.spight_at_gmail.com> wrote in message:
> > >
> > > The RA does not have any operations for looking at elements. :-O
> >
> > But the RA does rely on the existence of an operator that can test two
> > references to elements to see whether or not they refer to the same
element.
> > You can't do all the RA operators, if you can't tell the elements apart.
>
> Definitely. For every domain the RA operates on, it needs a
> value-equality
> test. This might make for some requirements on the type implementor or
> in might be possible to do automatically, but it must be done.

How can you choose between the type engine and the relational engine ? I guess you do implicit type conversions. Received on Wed Mar 08 2006 - 02:34:50 CST