1-Consider a relation R(A,B,C,D,E) with the following functional dependencies:

AB

CD E

E A

B D

Specify all minimal keys for R.

2-Consider a relation R(A,B,C,D,E,F,G,H) with the following functional dependencies:

A BCD

AD E

EFG H

F GH

Based on these functional dependencies, there is one minimal key for R. What is it?

3-Consider relation R=(A,B,C,D) with the following FDs:

AB C

CD

DA

List all candidate keys of R.

4-Consider relation S=(A,B,C,D) with the following FDs:

AB

BC

CD

DA

List all candidate keys of S.