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

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? 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?

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 Received on Sat Nov 04 2006 - 01:57:46 CET