Question
5. Consider the E-R
diagram in Figure 7-20. Based on this E-R diagram, answer the following
questions:
a. How many EMPLOYEES
can work on a project?
b. What is the degree
of the Used_on relationship?
c. Do any associative
entities appear in this diagram? If so, name them.
d. How else could the
attribute Skill be modeled?
e. What attributes
might be attached to the Works_on relationship?
f. Could TOOL be
modeled as an associative entity? Why or why not?
FIGURE 7-20 E-R
diagram for Problem and Exercise 5.
16. The owner of two
pizza parlors located in adjacent towns wants to computerize and integrate
sales transactions and inventory management within and between both stores. The
point-of-sale component must be easy to use and flexible enough to accommodate
a variety of pricing strategies and coupons. The inventory management, which
will be linked to the point-of-sale component, must also be easy to use and
fast. The systems at each store need to be linked so that sales and inventory
levels can be determined instantly for each store and for both stores combined.
The owner can allocate $40,000 for hardware and $20,000 for software and must
have the new system operational in three months. Training must be short and
easy. Briefly describe three alternative systems for this situation and explain
how each would meet the requirements and constraints. Are the requirements and
constraints realistic? Why or why not?
17. Compare the
alternative systems from Problem and Exercise 16 using the weighted approach
demonstrated in Figure 7-19. Which system would you recommend? Why? Was
the approach taken in this and Problem and Exercise 16 useful even for this
relatively small system? Why or why not?