distributed dbms cs712 power point slides lecture 1

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Distributed DatabaseDistributed DatabaseManagement SystemsManagement Systems

Lecture - 01

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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

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References

3- Distributed Systems: Concepts and Design, 4th Edition, by G. Coulouris, J. Dollimore, T. Kindberg, Addison-Wesley

Prerequisites: Database Management Systems, Computer Networks

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Course of Course

Introduction to database and Distributed Systems in general

Architectures and Design Issues of DDBS

Technological TreatmentTheoretical Aspects of the

topic

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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

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Program and Data Interdependence

RegistrationApplications

RegistrationDataFiles

RegistrationExaminationApplications

ExaminationDataFiles

Examination

LibraryApplications

LibraryDataFiles

Library

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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 DataVulnerable to Inconsistency

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History continues

Database Approach: (Also called centralized database) Database is a shared collection of logically related data

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Database

Data Description

Data Manipulation

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PROGRAM 1

PROGRAM 2

PROGRAM 3

Database Approach

Takes care of all major drawbacks of File System Environment plus more

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Distributed Computing SystemA number of autonomous processing elements that are connected through a computer network and that cooperate in performing their assigned tasks

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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

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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)

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Classifications of DCS Interconnection structure

Could be point to point or a common interconnection channel

Interdependence of Components Synchronization Factors are not totally independent

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Why DCS?

Suits some of the Organizational Structures; more reliable and responsive

Nature of some applications Technological Push

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DCS’s Alerts

Information Islands and Lack of Standards Difficulties in Large Application Design Too Many Options Available

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