Object-oriented (OO) technology requires a totally new mindset; developers create models that are mapped to real world processes. The object-oriented approach emphasizes a more natural representation of the data. In today's environment, the data models are more demanding. They need to handle audio, video, text, graphics, etc. These requirements demand a more flexible storage format than hierarchical, network, and relational databases can provide.

1. Advance Database Management Systems : 12
Encapsulation and its benefits
Prof Neeraj Bhargava
Vaibhav Khanna
Department of Computer Science
School of Engineering and Systems Sciences
Maharshi Dayanand Saraswati University Ajmer

2. Encapsulation of Operations, Methods, and
Persistence
• Encapsulation
– One of the main characteristics of OO languages
and systems
– Related to the concepts of abstract data types
and information hiding in programming languages

3. Object Behavior
• Specifying Object Behavior via Class
Operations:
– The main idea is to define the behavior of a type
of object based on the operations that can be
externally applied to objects of that type.
– In general, the implementation of an operation
can be specified in a general-purpose
programming language that provides flexibility
and power in defining the operations.

4. Object Behavior
• Specifying Object Behavior via Class
Operations (contd.):
– For database applications, the requirement that
all objects be completely encapsulated is too
stringent.
– One way of relaxing this requirement is to divide
the structure of an object into visible and hidden
attributes (instance variables).

5. Models mapped to real world processes
• In Object-Oriented databases, the focus is on objects, not
functions.
• Object-oriented (OO) technology requires a totally new
mindset; developers create models that are mapped to real
world processes.
• The object-oriented approach emphasizes a more natural
representation of the data. In today's environment, the
data models are more demanding. They need to handle
audio, video, text, graphics, etc. These requirements
demand a more flexible storage format than hierarchical,
network, and relational databases can provide.
• Only object-oriented databases will be able to support this
kind of demand.

6. Encapsulation of data and operations
inside an object
• The object technology model also provides for
the encapsulation of data and operations
inside an object.
• As long as the external interfaces remain
unchanged, developers can modify
encapsulated data and operations in an object
without affecting other objects.
• Encapsulation makes the data and procedures
private within an object.

7. OODBMS potential benefits
• The potential benefits of the object databases
are faster development, higher quality, easier
maintenance, and increased scalability and
adaptability.
• In addition the object databases claim to allow
the MIS personnel to better model the real-
world, resulting in better information
structures and reduced costs for systems.

8. Encapsulation of Operations, Methods, and
Persistence

9. Persistence
• Specifying Object Persistence via Naming and Reachability:
– Naming Mechanism:
• Assign an object a unique persistent name through which it can be
retrieved by this and other programs.
– Reachability Mechanism:
• Make the object reachable from some persistent object.
• An object B is said to be reachable from an object A if a sequence
of references in the object graph lead from object A to object B.

10. Specifying Object Persistence via Naming and
Reachability (contd.)
– In traditional database models such as relational
model or EER model, all objects are assumed to be
persistent.
– In OO approach, a class declaration specifies only
the type and operations for a class of objects. The
user must separately define a persistent object of
type set (DepartmentSet) or list (DepartmentList)
whose value is the collection of references to all
persistent DEPARTMENT objects

11. Encapsulation of Operations, Methods, and
Persistence (7)

12. Assignment
• Explain the concept of Encapsulation of
Operations, Methods, and Persistence