DAEYANG UNIVERSITY
COLLEGE OF ICT
END SEMESTER TWO EXAMINATION
ICT222: DATABASES
Date: 1 September 2020
Time: 06:00-23:59
Read these instructions carefully
1.
2.
3.
4.
5.
This paper contains FIVE questions, please check. Answer ALL of them.
Write your registration number on each answer sheet provided.
Begin answering each QUESTION on a fresh page.
Marks have been indicated at the end of each question, please check.
No books, dictionaries, phones, notes or any other reference materials are
allowed in this examination.
6. Do not open this paper until you are instructed to do so by the invigilator.
Question 1
a. Describe all the main stages of database application lifecycle.
b. Account for all the advantages of relational model.
(10 marks)
(10 marks)
Question 2
a. Draw a diagram that consists of two related tables. Fill the tables with at least
four tuples each. Clearly mark attributes, tuples, relations, primary and
foreign keys.
(12 marks)
b. Compare the RDBMS to OODBMS.
(8 marks)
Question 3
A company uses a number of items of equipment to produce goods. Each item has a
unique ID, and has a description. Defects on items are identified by unique IDs, have
descriptions, and are reported at a time represented by TimeReported.
Any number of technicians may be assigned to work on a fault until it is fixed. The
time at which each fault is fixed is recorded as TimeFixed. Each technician also
records the time spent (hours) on each fault as TimeSpent.
Any number of parts may be used to fix a fault. The QtyUsed of each part is noted
against the corresponding fault.
Each part is identified by an ID, has a given name and can have any number of
vendors.
Vendors are identified by an ID, a name and an address.
Each technician is identified by an ID, has a FullName and zero or more
qualifications.
Each qualification has a unique ID, name and awarding body. The date when a
technician has gained any given qualification is also recorded.
a. Transform the above scenario relation into 3NF. Using a recognised
modelling notation of your choice, draw an ERD model showing:
i.
The entity types, with corresponding attributes and primary keys.
ii.
Clearly name the relations and relation types i.e. (One:One; One:Many
or Many:Many).
State any assumptions you make to fill any gaps in the scenario.
(14 marks)
b. Design a set of tables derived from your Entity-Relationship model in part (a)
above. Clearly highlight all primary keys and foreign keys. Fill in the tables
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with sample data that represents all of the degrees of the relationships. Limit
the number of rows in any table to a maximum of 4 rows per table. (6 marks)
Question 4
a. Normalisation and Entity Relationship Diagrams are two techniques for
designing databases.
i.
Describe these two techniques.
(4 marks)
ii.
Give three advantages each of these two techniques?
(6 marks)
b. Many organisations have a choice to deploy their database resources and
services either using their own ICT infrastructure or ‘Cloud’. Explain five
strengths and limitations each of using cloud computing.
(10 marks)
Question 5
Below is a partial database for Education Management Information System (EMIS).
Pupils
PupilNo SchoolID SurName FirstName Sex BirthDate Class
Schools
SchoolID School
Teachers
EmployeeNo SchoolID NationalID TeacherName Sex BirthDate Grade Qual
Use the three relations to answer the following questions in:
A. Relational Algebra
B. SQL
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5.
Retrieve all pupils born before 01/01/2005 and not in Std 8.
Retrieve all senior pupils at Lingadzi FP School.
List all Std 8 pupils at Livimbo FP School.
Retrieve all teachers aged 50 and above on 01/07/2020.
List all teachers at Lingadzi FP School.
(4 marks)
(4 marks)
(4 marks)
(4 marks)
(4 marks)
END OF QUESTIONS
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