Why do we designate one of the candidate keys of a relation to be the primary key?

5.1Define the following terms as they apply to the relational model of data: domain, attribute, n-tuple, relation schema, relation state, degree of a relation, relational database schema, and relational database state. 5.2. Why are tuples in a relation not ordered? 5.3. Why are duplicate tuples not allowed in a relation? 5.4. What is the difference […]