POLYTECHNIC OF NAMIBIA 
SCHOOL OF INFORMATION TECHNOLOGY
SOFTWARE ENGINEERING DEPARTMENT
Private Bag 13388, Windhoek, Namibia Phone: +264 (61) 207-2052 
Fax: +264 (61) 207-2051 it@polytechnic.edu.na

INTRODUCTION TO DATABASES (IDB210S)
Assignment 1
TOTAL: 50 Marks |__|__|35 |_____| %
Date: 7th March 2011 

Instructions: Answer all the questions. No plagiarism will be tolerated! Work in a group with a maximum of 3 individuals (students and the minimum of 2 students ). When you answer questions, you should be led by the marks allocated for each question; keywords alone are not enough. 

1. Explain briefly what the main benefits of using a DBMS to manage data in program applications involving extensive data access. 
2. When would you store data in a DBMS instead of in operating system files and vice-versa? Motivate your answer. 
3. Explain the advantages of using a query language instead of custom programs to process data. Motivate your answer. 
4. What is a transaction? (1 Mark)
5. What guarantees does a DBMS offer with respect to transactions? Motivate your answer.

6. Mr. Sylvester Shongani wants to store information (names, addresses, descriptions of exciting moments, etc) about the many people he interacts with. Not surprisingly, the volume of data compels him to buy a database system. To save money, he wants to buy one with the least possible features, and he plans to run it as stand-alone application on his PC. Of course, Mr. Shongani does not plan to share his list with anybody. Indicate why Mr. Shongani should or should not pay for the following features in the system he buys. Explain your answers briefly. 
a. A security facility.
b. Concurrency control.
c. Crash recovery.
d. A view mechanism.
e. A query language.