Re: Relation Schemata vs. Relation Variables
Date: 1 Sep 2006 09:39:26 -0700
Right. I forgot ;)
> > but such treatment is also no
> > good since hidden row_id's is not part of the relational model.
> > Is it the case that the Dataphor relational assignment does not honor
> > any constraints ?
> Of course not. It's just TCs that are an issue, and the way they do it
> does make sense.
I understand that in Dataphor it's impossible, syntactically, to refer to the old relvar value for the purpose of defining a 'real' TC constraint, right ? Interestingly, it would have been trivial to implement such feature efficiently in a multiversioning database but apparently they did not want to be implementation dependent although they could have used less efficient ways to do so in other databases..
Received on Fri Sep 01 2006 - 18:39:26 CEST