Question

What are the possible sources of the information that defines the functional dependencies that hold among the attributes of a relation schema? Discuss two possible sources. Explain your answer.

Answer 1

A functional dependency describes a relationship between the attributes of an entity such that the value of one attribute is dependent on the value of some other attribute and is very well affected by it.

There can be various sources of information that define functional dependency. For instance, an attribute age can define the functional dependency with the attribute ID. One cannot include the voter ID if they are not above 18 years of age.

Similarly, the attribute date of joining can define the functional dependency with the attribute experience, as the experience in a particular organization can be calculated by subtracting the joining date fro the current date.