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In the name of Allah. Distributed Database Management Systems. Lecture - 01. References. 1- Distributed Database Systems (2 nd Edition) by T.M., Ozsu, P. Valdusiez 2- Distributed Database Systems. By D. Bell, J. Grimson, Addison-Wesley, 1992 . References.
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Distributed DatabaseManagement Systems Lecture - 01
References 1-Distributed Database Systems (2ndEdition) by T.M., Ozsu, P. Valdusiez 2- Distributed Database Systems. By D. Bell, J. Grimson, Addison-Wesley, 1992
References 3- Distributed Systems: Concepts and Design, 4th Edition, by G. Coulouris, J. Dollimore, T. Kindberg, Addison-Wesley Prerequisites: Database Management Systems, Computer Networks
Course of Course • Introduction to database and Distributed Systems in general • Architectures and Design Issues of DDBS • Technological Treatment • Theoretical Aspects of the topic
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
Registration Examination Library Registration Applications Examination Applications Library Applications Registration Data Files Examination Data Files Library Data Files Program and Data Interdependence
File Processing Systems Duplication of Data Vulnerable to Inconsistency
History continues Database Approach: (Also called centralized database) Database is a shared collection of logically related data
PROGRAM 1 Data Description Database PROGRAM 2 Data Manipulation …. PROGRAM 3 Database Approach Takes care of all major drawbacks of File System Environment plus more
Distributed Computing System A number of autonomous processing elements that are connected through a computer network and that cooperate in performing their assigned tasks
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
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)
Classifications of DCS • Interconnection structure • Could be point to point or a common interconnection channel • Interdependence of Components • Synchronization • Factors are not totally independent
Why DCS? • Suits some of the Organizational Structures; more reliable and responsive • Nature of some applications • Technological Push
DCS’s Alerts • Information Islands and Lack of Standards • Difficulties in Large Application Design • Too Many Options Available