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(COMP231)comp231_pp2006_sol.pdf
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HONG KONG UNIVERSITY OF SCIENCE & TECHNOLOGY
COMP231: Database Management Systems
Spring Semester, 2006
Final Examination
May 27, 2006 4:30 C 7:30 p.m.

Name: ___________________ Student Number: ______________________

Email: ___________________ Lab Section Number:____________________

















Questions
Marks
Scores

1
10


2
16


3
12


4
16


5
14


6
16


7
16


Total
100




T1 T2 T3 T4



Instructions:



1. This examination paper consists of 20 pages and 7 questions.

2. Please write your name, student ID and Email on this page.
3. For each subsequent page, please write your student ID at the top of the page in the space provided.

4. Please answer all the questions within the space provided on the examination paper. You may use the back of the pages for your rough work and afterwards draw a diagonal line through it to show that it is not part of your answer.
5. Please read each question very carefully and answer the question clearly and to the point. Make sure that your answers are neatly written, readable and legible.

6. Leave all pages stapled together.

7. The examination period will last for 3 hours.

8. Stop writing immediately when the time is up.

Question 1 General Database Knowledge. (10 marks)

(a) (3 marks) Explain the benefits of having logical data independence and physical data independence in the context of Database Management Systems (DBMSs). You may refer to the following diagram whenever necessary.













. The advantage of having physical data independence is that we may upgrade the physical technologies easily in a rapidly changing environment, for example replacing with a more powerful database server does not affect the definition of the data.

. The advantage of having logical data independence is that the view definitions are not affected by any changes in the underlying database schema.




(b) (3 marks) Discuss the three roles of a Database Administrator (DBA) which are different from casual users in managing a DBMS.



Any three of the following or some other reasonable answers

. Schema definition

. Specifying integrity constraints

. Storage structure and access method definition

. Schema and physical organization modification

. Granting user authority to access the database

. Acting as liaison with users

. Monitoring performance and responding to changes in requirements

. Provide tools to access and update the data and produce reports

. Inform and assist users in planning and using data resources and database management tools

. Maintain database integrity by protecting its existence, maintaining it quality and controlling access to private data



(c) (2 marks) Assume a student develops a system using JAVA