Re: Bidirectional Binary Self-Joins

On Mar 31, 4:45 am, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
> Marshall wrote:
> > On Mar 30, 12:04 pm, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
>
> >>It would use the equality operation to detect the duplicate. What's more
> >>disturbing is it would allow the following without complaint:
>
> >>{ date=12-Dec, teamscores={(team=Calvin, score=31), (team=Hope, score=59) }}
>
> > Whether it complained or not would depend on the keys and other
> > constraints.
>
> Other constraints maybe... keys absolutely not.

Lately the distinction seems artificial to me.

> > In another subthread I proposed the following key:
>
> > (date, π_team(teamscores))
>
> > Isn't that a kick?
>
> Since when is π_team(teamscores) an attribute of the relation?

Hence the kick. :-)

Marshall Received on Sat Mar 31 2007 - 16:46:54 CEST