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 . Exercises ER and UML Conceptual Data Modeling Problem 2-1 Draw a detailed ER diagram for an car rental agency database . 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. .
