Module II Object Oriented and Extended Relational Database Technologies

Introduction to OODBMS

• An object database or object-oriented database is a database management system in which information is represented in the form of objects as used in object-oriented programming. Object databases are different from relational databases which are table-oriented.
• OODBMS stands for Object-Oriented Database Management System. It is a DBMS where data is represented in the form of objects, as used in object-oriented programming. OODB implements object-oriented concepts such as classes of objects, object identity, polymorphism, encapsulation, and inheritance. An object-oriented database stores complex data as compared to relational database. Some examples of OODBMS are Versant Object Database, Objectivity/DB, ObjectStore, Caché and ZODB.

Object Oriented Programming Concepts

• Inheritance
• Polymorphism
• Abstraction
• Encapsulation

Polymorphism

• If one task is performed in different ways, it is known as polymorphism. For example: to convince the customer differently, to draw something, for example, shape, triangle, rectangle, etc.
• In Java use method overloading and method overriding to achieve polymorphism.
• Another example can be to speak something; for example, a cat speaks meow, dog barks woof, etc.

Inheritance

• When one object acquires all the properties and behaviors of a parent object , it is known as inheritance. It provides code reusability. It is used to achieve runtime polymorphism.

Encapsulation

• Binding (or wrapping) code and data together into a single unit are known as encapsulation. For example, a capsule, it is wrapped with different medicines.
• A java class is the example of encapsulation. Java bean is the fully encapsulated class because all the data members are private here.