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IELM 230 Industrial Data Systems, Fall 2005
Assignment 2. Due Date: Oct 12, Max score: 15

Q1. ER diagrams [2+2+3=7 pts]
Figure 1 below shows a ternary relationship (SUPPLY) between SUPPLIER, PART and PROJECT entities. Figure 2 shows an incomplete ER diagram to represent the same information using binary relationships.
Assume that suppliers may have supplied multiple parts, each project uses several parts, and some parts may be used in different projects.



Figure 1. Ternary relationship SUPPLY


Figure 2. Binary relationships

(a) What needs to be added to Figure 2 to make it complete?
(b) Show the cardinality constraints on the binary relationships.
(c) Show that the two ER diagrams are equivalent [Hint: to do so, you must show that each situation that can be represented by one diagram can also be represented by the other.]

Q2. Informal design [8 pts]
Use the model solution for Assignment 1, with the ER diagram for facilities booking. Using the informal guidelines given in the lecture notes, convert this ER diagram into DB schema designs. Mark the primary key and foreign keys for each schema.