Questions from Database Systems

Q: The execution of a trigger can cause another action to be triggered

The execution of a trigger can cause another action to be triggered. Most database systems place a limit on how deep the nesting can be. Explain why they might place such a limit.

Q: Explain the distinctions among the terms primary key, candidate key,

Explain the distinctions among the terms primary key, candidate key, and super key.

Q: Design a database for a worldwide package delivery company (e.

Design a database for a worldwide package delivery company (e.g., DHL or FedEx). The database must be able to keep track of customers who ship items And customers who receive items; some customers may...

Q: Design a database for an airline. The database must keep track

Design a database for an airline. The database must keep track of customers and their reservations, flights and their status, seat assignments on individual flights, and the schedule and routing of futu...

Q: In Section 6.9.4, we represented a ternary

In Section 6.9.4, we represented a ternary relationship (repeated in Figure 6.29a) using binary relationships, as shown in Figure 6.29b. Consider the alternative shown in Figure 6.29c. Discuss the rel...

Q: Design a generalization– specialization hierarchy for a motor vehicle sales company

Design a generalization– specialization hierarchy for a motor vehicle sales company. The company sells motorcycles, passenger cars, vans, and buses. Justify Your placement of attribu...

Q: Explain the distinction between disjoint and overlapping constraints.

Explain the distinction between disjoint and overlapping constraints.

Q: Explain the distinction between total and partial constraints.

Explain the distinction between total and partial constraints.

Q: Explain what a challenge– response system for authentication is. Why

Explain what a challenge– response system for authentication is. Why is it more secure than a traditional password-based system?

Q: Construct an E-R diagram for a hospital with a set

Construct an E-R diagram for a hospital with a set of patients and a set of medical doctors. Associate with each patient a log of the various tests and examinations conducted.