What do you understand by the candidate key and cardinality of a relation in relational data base?

DATABASE MANAGEMENT SYSTEM

What do you understand by the candidate key and cardinality of a relation in relational data base?

Ans. Candidate Key: All attribute combinations inside a relation that can serve as primary key (uniquely identifies a row in a relation) are Candidate Keys as they are candidates for the primary key position. The number of rows in a relation is known as cardinality of a relation.