Question :

Object-Oriented Database (OODM) is defined as a logical data model that captures the semantics of objects supported in object-oriented programming. An Object-Oriented Database or OODB is defined as a persistent and sharable collection of objects defined by an OODM.

(i) OODBMSs were developed due to some of the inadequacies of the existing database technology. One of the inadequacies refers as Impedance mismatch problem. Explain what is meant by impedance mismatch, in the context of relational database system.

(ii) Give example of Four Advanced Database Applications and discuss their general characteristics. Explain why these applications are not suitable for a relational database.

(iii) Define each of the following concepts in the context of an object-oriented data model:

a. Abstraction.
b. Objects and attributes.
c. Methods and messages.
d. Classes, subclasses and superclasses.