(a) Explain briefly the three parts of a relational Model.
(b) Contrast the following terms with an appropriate example:
(i) stored attribute v/s derived attribute
(ii) entity type v/s entity instance
(iii) strong entity type v/s weak entity type
(iv) simple attribute v/s composite attribute
(v) unary relationship v/s binary relationship.
(c) The term integrity refers to the accuracy or correctness of the data in the database. Define the following terms:
(i) Domain Integrity
(ii) Entity Integrity
(iii) Referential Integrity.
(d) Constraints are rules that restrict the data values that you can enter into a field in a database table. Briefly describe the following constraint with appropriate example for each:
(i) Check Constraint
(ii) Not Null Constraint
(iii) Unique Constraint