Data models can facilitate communication between designers, programmers, and users. A well-developed data model can improve understanding of an organization. Data models are a communication tool that represent different types of relationships in a database. Common data models include hierarchical, network, relational, entity-relationship, and object-oriented models. Each model has advantages like conceptual simplicity and flexibility as well as disadvantages like complexity and implementation limitations.

1. IMPORTANCE
OF
DATA MODEL

2.  Data models can facilitate
interaction among the
designer, the application
programmer and the end user.

3.  A well- developed data model can
even foster improved
understanding of the
organization for which the
database design is developed.

4.  Data models are a
communication tool.

5. ADVANTAGES
and
DISADVANTAGES
of

6. HIERARCHICAL
DATA MODEL

7. ADVANTAGES:
 It promotes data sharing.
 Parent/child relationship promotes
conceptual simplicity.
 Database security is provided and
enforce by DBMS.

8. ADVANTAGES:
 Parent/child relationship
promotes data integrity.
 It is efficient with 1:m
relationship.

9. Disadvantages:
 Complex implementation requires
knowledge of physical data storage
characteristics.
 Navigational system yields complex
application
development, management, and
used; requires knowledge of
hierarchical path.

10.  Changes in structure require changes in all
applications.
 There are implementation limitation.
 There is no data definition or data
manipulation language in DBMS.
 There is a lack of standards.

11. NETWORK
DATA MODEL

12. ADVANTAGES:
 Conceptual simplicity is at least equal to that
of the hierarchical model.
 It handles more relationship type, such as m:n
and multi-parent.
 Data access is more flexible.

13. ADVANTAGES:
 Data owner/ member promotes data
integrity.
 There is conformance to standards.
 It includes data definition language (DDL)
and data manipulation language (DML)

14. DISADVANTAGES:
 System complexity limits efficiency.
 Navigational system yields complex
implementation, application development
and management.
 Structural changes require changes in all
application programs.

15. RELATIONAL
DATA MODEL

16. ADVANTAGES:
 Structural independence is promoted by the
use of independent tables. Changes in a tables
structure do not affect data access or
application programs.
 Tabular view substantially improves
conceptual simplicity, thereby promoting
easier database
design, implementation, management and
use.

17. ADVANTAGES:
 AD HOC query capability is based on SQL.
 Powerful RDBMS isolates the end user from
physical level details and improves
implementation and management simplicity.

18. DISADVANTAGES:
 The RDBMS requires substantial hardware
and system software overhead.
 Conceptual simplicity gives relatively
untrained people the tools to use a good
system poorly, and if unchecked, it may
produce the same data anomalies found in
file systems.

19. DISADVANTAGES:
 IT may promote island of information.

20. ENTITY RELATIONSHIP
DATA MODEL

21. ADVANTAGES:
 Visual modeling yields exceptional
conceptual simplicity.
 Visual representation makes it an effective
communication tool.
 It is integrated with dominant relational
model.

22. Disadvantages:
 There is limited constraints representation.
 There is limited relationship representation
 There is no DML.
 Loss of information content occurs when
attributes are removed from entities to avoid
crowded displays.

23. OBJECT- ORIENTED
DATA MODEL

24. ADVANTAGES:
 Semantic content is added.
 Visual representation includes semantic
content.
 Inheritance promotes data integrity.

25. Disadvantages:
 Slow development of standards caused
vendors to supply their own
enhancements, thus eliminating a widely
accepted standards.
 It is a complex navigational systems.

26. Disadvantages:
 There is a steep learning curve.
 High system overhead slows transactions.