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Database Modeling & Design Fourth Edition- P53

Database Modeling & Design Fourth Edition- P53: Database technology has evolved rapidly in the three decades since the rise and eventual dominance of relational database systems. While many specialized database systems (object-oriented, spatial, multimedia, etc.) have found substantial user communities in the science and engineering fields, relational systems remain the dominant database technology for business enterprises. | References 247 Zachmann J. A. A Framework for Information Systems Architecture IBM Systems Journal 26 3 1987 IBM Pub. G321-5298. Zachmann Institute for Framework Advancement http www.zifa.com. Exercises ER and UML Conceptual Data Modeling Problem 2-1 Draw a detailed ER diagram for an car rental agency database e.g. Hertz keeping track of the current rental location of each car its current condition and history of repairs customer information for a local office expected return date return location car status ready being-repaired currently-rented being-cleaned . Select attributes from your intuition about the situation and list them separately from the diagram but associated with a particular entity or relationship in the ER model. Problem 2-2 Given the following assertions for a relational database that represents the current term enrollment at a large university draw an ER diagram for this schema that takes into account all the assertions given. There are 2 000 instructors 4 000 courses and 30 000 students. Use as many ER constructs as you can to represent the true semantics of the problem. .