Re: Basic question?What 's the key if there 's no FD(Functional Dependencies)?

Aloha Kakuikanu wrote:
> NENASHI, Tegiri wrote:
> > Jan Hidders wrote:
> > > Do you know of any results that might be interesting for database
> > > theory and could not already be shown with good old set theory?
> >
> > The categorical sketches to use for universal view updatability:
> >
> > Michael Johnson and Robert Rosebrugh.
> > Universal view updatability
>
> They claim to solve view updatability?

No they claim to find out the universal property when the view can be updated. See the article.

>

OK, I have a table RealPeople
> with one attribute Name and the view
>
> CDTPosters =
> RealPeople
> union
> {(name=TeGiriNeNashi)}
>
> and a constraint
>
> RealPeople
> intersect
> {(name=TeGiriNeNashi)}
> =
> {}
>
> Is the CDTPosters view updatable?
>

In sketches the constraints are defined by diagram commutability. The view is not updatable because the diagram does not commute.

>
> BTW, how is that lawsuit against the movie industry is going?
> http://groups.google.com/group/alt.video.dvd.tech/browse_frm/thread/ec185c0b13e02f7e/b5537612074bd38d?lnk=st&q=&rnum=2&hl=en#b5537612074bd38d

It is some confusion. My father was laywer but he is retired 7 years already. Received on Sat Nov 04 2006 - 03:20:43 CET