Re: grouping in tuple relational calculus
Date: Wed, 16 Feb 2005 10:53:12 -0800
Message-ID: <3RMQd.35$YQ1.109_at_news.oracle.com>
Speaking of aggregates, I always wondered why some aggregates are expressable by standard means (min, max can be expressed as antijoins), while the others aren't (sum).
"Antonio Martinez" <antonio_at_colpos.mx> wrote in message
news:e0fac771.0502161021.13573811_at_posting.google.com...
> Thanks a lot for the pointer!
>
> I also found something in Date
> that is easy to translate to
> set notation.
>
> Thxs!
>
> "Mikito Harakiri" <mikharakiri_at_iahu.com> wrote in message
news:<s4vQd.28$BP3.131_at_news.oracle.com>...
> > "Antonio Martinez" <antonio_at_colpos.mx> wrote in message
> > news:e0fac771.0502151328.630ece22_at_posting.google.com...
> > > Does anybody know how to represent
> > > grouping queries in tuple relational
> > > calculus? either that or an extension
> > > that allows such operations ? (avg, sum,
> > > etc)
> > >
> > > any pointers will be very wellcome!
> >
> > The Alice book, pg 93?
Received on Wed Feb 16 2005 - 19:53:12 CET