NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
APRIL/MAY 2019 EXAMINATION

COURSE CODE: CIT427

COURSE CREDIT: 3 units

COURSE TITLE: DATABASE SYSTEMS AND MANAGEMENT

TIME ALLOWED: 3 Hours

INSTRUCTION: Answer Question 1 and any other Four questions

Question 1

(a)         Outline four (4) operations a relational algebra can undergo. (4 marks)

(b)         State any five (5) database activities that Data definition language provides command for (5 marks)

(c)          List four (4) components of a data structure. (4 marks)

(d)         Mention any three (3) categories of Object-based logical models. (3marks)

(e)         Explain data definition language (DDL). (3 marks)

(f)          Briefly discuss data manipulation language (DML). (3 marks)

(Total = 22 marks)

Question 2

(a)         Define Data Independence (2 marks)

(b)         List the various classes of schema that we have. (3 marks)

(c)          List and explain the categories of data independence. (7 marks)

(Total = 12 marks)

Question 3

(a)         Describe the types of Database that we have. (9 marks)

(b)         Write short notes on the following :

i.            Entity-relationship model  (11/2 marks)

ii.           Object-oriented model (11/2 marks)

(Total = 3 marks)

(Total = 12 marks)

Question 4

(a)         List the features of Database Management System (DBMS) and describe any three (3) (8 marks)

(b)         When do we use the UPDATE command in SQL language? Use any algorithm as example (3 marks)

(c)          State the syntax for INSERT command as it is used in SQL programming (1 mark)

(Total = 12 marks)

Question 5

(a)         List any three (3) of the guidelines usually adopted in domain construct implementation     (6 marks)

(b)         In the context of computer storage devices, explain the following:

(i)           Primary storage devices (3 marks)

(ii)          Secondary memory storage devices(3 marks)

(Total = 12 marks)

Question 6

(a)         Explain four (4) common methods of file organization (8 marks)

(b)         Define two of the following as used in XML. Give an example of each. (2marks each)

(a)         Elements

(b)         Attributes

(c)          Processing instructions (PIs)

(Total = 12 marks)