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Distributed Database Management Systems: Lecture 5. The main topics covered in this chapter include: data model; legacy data models; a set of tools/constructs used to model a database; record/semantic; relational data model; primary key;...
Distributed Database Management System Lecture 05 Data Model • A set of tools/ constructs used to model a database • Record/Semantic Virtual University of Pakistan Legacy Data Models • Hierarchical • Network • Relational Virtual University of Pakistan Relational Data Model • Two major Strengths • Three Components • Relational databases based on relational Data Model Virtual University of Pakistan • A relation R defined over domains D1, D2, …., Dn is a set of n-tuples, such that