Re: more on delete from join
Date: Thu, 27 Aug 2009 12:40:08 -0700 (PDT)
On Aug 27, 11:14 am, TroyK <cs_tr..._at_juno.com> wrote:
> On Aug 26, 3:51 pm, Tegiri Nenashi <tegirinena..._at_gmail.com> wrote:
> > On Aug 26, 1:03 pm, paul c <toledobythe..._at_oohay.ac> wrote:
> > Stop right there. You were writing R UNION A, so R and A are relations
> > (or predicates) and not propositions. Once again, some propositions
> > are predicates (namely 0-ary ones), but most of them aren't!
> In one of his dbdebunk papers (and probably in other writings), Date
> gives the following definition:
> "A proposition is a predicate in which all variables are bound; ...".
> This doesn't to match with your statement above. What propositions are
> not predicates? Is there another notion to the term that Date is
> ignoring that you're using for this discussion?
It should read "...some predicates (namely 0-ary ones) are propositions, but most of them aren't...". Thanks for catching it. Received on Thu Aug 27 2009 - 21:40:08 CEST