NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
MARCH/APRIL 2015 EXAMINATION

COURSE CODE:                                                                                     CIT 427

COURSE TITLE:                                                                                      Database Systems and Management

TIME ALLOWED:                                                                   3 HOURS

INSTRUCTION: Answer any five (5) questions

QUESTIONS

1a. State four (4) key rules guiding the execution of domain constraints.                (8 marks)

1b. Write down the main component of the following:

i. Foreign key                                                                                                                                        (2 marks)

ii. Primary key                                                                                                                                       (2 marks)

iii. Unique key                                                                                                                                       (2 marks)

                                                                                                                                                                [Total=14 marks]

2a. Give a concise description of Offline Storage within the context of database management.

                                                                                                                                                                (8 marks)

2b. Write down the full meaning of XML.                                                                              (2 marks)

2c. What is the significance of the data query language?                                                (2 marks)

                                                                                                                                                                [Total=14 marks]

3a. Based on your knowledge of database management systems, explain the concept object based logical models.                                                                                                         (2 marks)

3b. Database Management Systems consist of 4 major components. List and describe these components.                                                                                                                                           (12 marks)

                                                                                                                                                                [Total=14 marks]

4a. Based on the W3C recommendation. The Extensible Markup Language sets out the a number of goals. State any 4 of these goals.                                                        (8 marks)

4b. Specify the 6 types of markup that can occur in an XML.                         (6 marks)

                                                                                                                                                                [Total=14 marks]

5a. Write down the symbol for accomplishing the following tasks in XML:

i. Producing a single quote character

ii. Producing the right angle bracket

iii. Producing a double quote

iv. Producing a left angle bracket

                                                                                                                                (1 mark and each, Total=4 marks)

5b. Give a concise description of the Magneto-optical disc storage.                          (6 marks)

5c. State the main difference between Line-sequential files and Sequential files. (4 marks)

                                                                                                                                                                [Total=14 marks]                

6a. How are attributes represented in Entity - Relationship diagrams?                     (2 marks)

6b. Give at least 3 typical forms of the object based logical models.                          (6 marks)

6c. Write down any 2 advantages of Web services.                                                                           (6 marks)

                                                                                                                                                                [Total=14 marks]

7a. Write short notes on the following :

a. Paper data storage                                                                                                                     (4 marks)

b. Parameter entities                                                                                                                     (4 marks)

c. Dynamic random access memory                                                                                         (4 marks)

d. File manager                                                                                                                 (2 marks)

                                                                                                                                                                [Total=14 marks]