Question

A  _________ Fc for F is a set of dependencies such that F logically implies all dependencies in Fc, and Fc logically implies all dependencies in F.

(a) Canonical cover

(b) Complete cover

(c) Canonical dependency

(d) Canonical clause

I had been asked this question at a job interview.

The origin of the question is Functional-Dependency Theory in section Relational Database Design of RDBMS

Answer 1

The correct choice is (a) Canonical cover

Explanation: A Canonical cover Fc for F is a set of dependencies such that F logically implies all dependencies in Fc, and Fc logically implies all dependencies in F. In Fc, no functional dependency should contain an extraneous attribute and each left side of functional dependency should be unique.