Обсуждение: Functional dependencies

Alpha Beta wrote:
> Hi list,  (newbie with databases)
>
> I was looking out in net about how can we determine or find all
> functional dependencies in a  relational database, but didn't find.
>
> So can please anyone here tell me if functional dependecies for each
> table of a relational database can be found explicitly or
> we need algorithms for it or any other way?
>
> Best regards!

Look for pairs of columns/attributes X and Y (or X may be a set of
columns/attrs) where, for every row/tuple having the same value for X, the
row/tuple always has the same value for Y.  In this situation, for the data you
have at least, there would seem to be a relationship where X determines Y and Y
depends on X.  Use an algorithm that does this looking for pairs. -- Darren Duncan