ddbms

1. Virtual University of Pakistan
In the name of
Allah

2. 2Virtual University of Pakistan
Distributed DatabaseDistributed Database
Management SystemsManagement Systems
Lecture - 01

3. 3Virtual University of Pakistan
1-Distributed Database Systems (2nd
Edition) by T.M., Ozsu, P. Valdusiez
2- Distributed Database Systems.
By D. Bell, J. Grimson, Addison-
Wesley, 1992
References

4. 4Virtual University of Pakistan
References
3- Distributed Systems: Concepts and
Design, 4th
Edition, by G. Coulouris,
J. Dollimore, T. Kindberg, Addison-
Wesley
Prerequisites: Database Management
Systems, Computer Networks

5. 5Virtual University of Pakistan
Course of Course
Introduction to database and Distributed
Systems in general
Architectures and Design Issues of
DDBS
Technological Treatment
Theoretical Aspects of the topic

6. 6Virtual University of Pakistan
Little bit of History
Traditional File Processing
System: the very first form of
business data processing
Each program contains data
description that it manipulates
Redundancy of data
Problems in maintenance

7. 7Virtual University of Pakistan
Program and Data Interdependence
Registration
Applications
Registration
Data
Files
Registration
Examination
Applications
Examination
Data
Files
Examination
Library
Applications
Library
Data
Files
Library

8. 8Virtual University of Pakistan
Library Exam Registration
Reg_Number Reg_Number Reg_Number
Name Name Name
Father Name Address Father Name
Books Issued Class Phone
Fine Semester Address
Grade Class
File Processing Systems
Duplication of Data
Vulnerable to Inconsistency

9. 9Virtual University of Pakistan
History continues
Database Approach: (Also called
centralized database) Database is a
shared collection of logically related
data

10. 10Virtual University of Pakistan
Database
Data
Description
Data
Manipulation
….
PROGRAM 1
PROGRAM 2
PROGRAM 3
Database Approach
Takes care of all major drawbacks of File
System Environment plus more

11. 11Virtual University of Pakistan
Distributed Computing System
A number of autonomous processing
elements that are connected through a
computer network and that cooperate
in performing their assigned tasks

12. 12Virtual University of Pakistan
Distributed Computing Systems
Distributed System Software enables
computers to coordinate and share
The thing being distributed?
– Processing logic
– Functions
– Data
– Control; All are relevant and important here

13. 13Virtual University of Pakistan
Classifications of DCS
Degree of Coupling
– How closely systems are connected
– May be the measured as ratio of
messages interchanged to the local
processing
– Could be Weak (over the network) or
Strong (if components are shared)

14. 14Virtual University of Pakistan
Classifications of DCS
Interconnection structure
– Could be point to point or a common
interconnection channel
Interdependence of Components
Synchronization
Factors are not totally independent

15. 15Virtual University of Pakistan
Why DCS?
Suits some of the Organizational
Structures; more reliable and
responsive
Nature of some applications
Technological Push

16. 16Virtual University of Pakistan
DCS’s Alerts
Information Islands and Lack of
Standards
Difficulties in Large Application
Design
Too Many Options Available