Database Management Systems
Assignment 02
Due date: 1 August 2012 NB: Make sure you select the correct unique number for your module from those indicated below. Unique number 759546 Tutorial matter covered in the prescribed book Chapters 1 - 3: Chapter 5: Chapter 6: Chapter 7: Chapter 12: Chapter 14: Chapter 16: Revise as for Assignment 01 Entity relationship modelling Advanced data modelling Normalisation of database tables Transaction management and concurrency control Distributed database management systems Database connectivity and web development
Question 1
What is a composite entity, and when is it used?
[4 marks] [8 marks]
Question 2
Briefly, but precisely, explain the difference between single-valued attributes and simple attributes. Give an example of each.
Question 3
[14marks]
Use the following business rules to create an ERD using UML notation. Write all appropriate multiplicities in the ERD. • A department employs many employees, but each employee is employed by one department. • Some employees, known as “rovers,” are not assigned to any department. • A division operates many departments, but each department is operated by one division. • An employee may be assigned many projects, and a project may have many employees assigned to it. • A project must have at least one employee assigned to it. • One of the employees manages each department, and each department is managed by only one employee. • One of the employees runs each division, and each division is run by only one employee.
Question 4
[20 marks]
The FlyRight Aircraft Maintenance (FRAM) division of the FlyRight Company (FRC) performs all maintenance for FRC’s aircraft. Produce a data model segment that reflects the following business rules: • All mechanics are FRC employees. Not all employees are mechanics. • Some mechanics specialise in engine (EN) maintenance. Some mechanics specialise in airframe (AF) maintenance. Some mechanics specialise in avionics (AV) maintenance. (Avionics are the
Due date: 1 August 2012 NB: Make sure you select the correct unique number for your module from those indicated below. Unique number 759546 Tutorial matter covered in the prescribed book Chapters 1 - 3: Chapter 5: Chapter 6: Chapter 7: Chapter 12: Chapter 14: Chapter 16: Revise as for Assignment 01 Entity relationship modelling Advanced data modelling Normalisation of database tables Transaction management and concurrency control Distributed database management systems Database connectivity and web development
Question 1
What is a composite entity, and when is it used?
[4 marks] [8 marks]
Question 2
Briefly, but precisely, explain the difference between single-valued attributes and simple attributes. Give an example of each.
Question 3
[14marks]
Use the following business rules to create an ERD using UML notation. Write all appropriate multiplicities in the ERD. • A department employs many employees, but each employee is employed by one department. • Some employees, known as “rovers,” are not assigned to any department. • A division operates many departments, but each department is operated by one division. • An employee may be assigned many projects, and a project may have many employees assigned to it. • A project must have at least one employee assigned to it. • One of the employees manages each department, and each department is managed by only one employee. • One of the employees runs each division, and each division is run by only one employee.
Question 4
[20 marks]
The FlyRight Aircraft Maintenance (FRAM) division of the FlyRight Company (FRC) performs all maintenance for FRC’s aircraft. Produce a data model segment that reflects the following business rules: • All mechanics are FRC employees. Not all employees are mechanics. • Some mechanics specialise in engine (EN) maintenance. Some mechanics specialise in airframe (AF) maintenance. Some mechanics specialise in avionics (AV) maintenance. (Avionics are the