EXAMINERS:
FIRST: Mr ME Bogopa
SECOND: Ms CL Hlengwa
This paper consists of 5 pages.
Instructions:
1. Answer all questions.
2. The marks for each question are given in brackets next to the question.
3. Please answer the questions in the order in which they have been set.
4. You signed an Honesty Declaration. This means you will complete this paper on
your own and without help.
5. This final pdf document should not be password protected.
6. Convert all the pages into a single PDF file.
7. Poorly scanned and hard to read answer files will result in a zero mark.
8. Once your document meets all the criteria, then you can upload the file to myAdmin.
GOOD LUCK.
, 2
INF2603
October/November 2022
QUESTION 1 [20 marks]
Carefully select the most correct answer to each of the following questions. Please write
down only the question number and corresponding to it put the correct option’s number
(e.g. Qu. 1 (e)).
1. Which of the following is NOT a true statement about constraints:
a. Constraints are important because they help to ensure data integrity.
b. Constraints support high-level inserts, updates and deletes.
c. Constraints are normally expressed in the form of rules.
d. A constraint is a restriction placed on the data.
2. The logical view of the relational database is facilitated by the ____.
a. objects defined by the database wizard
b. file system used by the operating system
c. creation of queries using the database wizard
d. creation of data relationships based on a construct known as a table
3. ______ is a common term used in traditional entity relationship modelling, and is used to express
the maximum number of entity occurrences associated with one occurrence of the related entity.
a. Participation
b. Cardinality
c. Multiplicity
d. Association
4. What is the purpose of an entity cluster?
a. define physical database storage for related entities
b. group related entities into a single table
c. improve readability of the ERD
d. make the ERD more complex
5. A query language is a procedural language.
a. True
b. False
6. Business rules apply to businesses and government groups, but not to other types of organisations
such as religious groups or research laboratories.
c. True
d. False
7. In the object-oriented data model (OODM), both data and their relationships are contained in a single
structure known as a(n) ____.
a. entity
b. attribute
c. Constraint
d. Object.
TURN OVER
, 3
INF2603
October/November 2022
8. Which of these is NOT a property of a relation?
a. Each table column represents an attribute, and each column has a distinct name.
b. The order of the rows and columns is important within a DBMS.
c. A table is perceived as a two-dimensional structure composed of rows and columns
d. Each column has a specific range of values known as the attribute domain.
9. Which attribute(s) make up the primary key in the table definition CLASS (CRS_CODE,
CLASS_SECTION, CLASS_TIME, CLASS_ROOM, PROF_NUM)?
a. CRS_CODE
b. CLASS_SECTION
c. CRS_CODE and CLASS_SECTION
d. there is no primary key.
10. Which statement about NULL values is NOT True?
a. A null does not mean a zero or a space.
b. Nulls should be avoided where ever possible
c. The existence of nulls in a table is often an indication of poor database design.
d. To maintain entity integrity, a null ‘value’ is permitted in the primary key.
QUESTION 2 [14 marks]
a. What are the six levels on which the quality of data can be examined? (6)
b. Given the below table structure, what data redundancies do you detect, and how could these
redundancies lead to anomalies? (6)
Table 2.1 The file structure for Problem 2b
PROJ_NUMB PROJ_NAME EMP_NUM EMP_NAME JOB_CODE JOB_CHG_HOUR PROJ_HOURS EMP_CELLPHONE
101 Mogamolo 2011 Previn B. Mochabo ZCM R1300.00 17.7 083-691-6060
101 Mogamolo 2051 Tumy A. Seoka KZN R800.00 20.6 072-369-9935
101 Mogamolo 2101 Charlotte P. Mkhize KZN R800.00 18.7 011-670-9085
102 Savana 2011 Previn B. Mochabo ZCM R1300.00 24.2 083-691-6060
102 Savana 2081 Thabo P. Mtsweni ZCM R1300.00 21.9 072-227-3895
103 Nuclear 2101 Charlotte P. Mkhize KZN R840.00 15.0 011-670-9085
103 Nuclear 2051 Tumy A. Nxumalo KZN R120.00 27.8 072-369-9935
103 Nuclear 2231 Daphny M. Zulu ZCM R1300.00 23.5 065-155-6553
103 Nuclear 2121 Mampilo M. Seoka BEE R1300.00 25.1 081-021-9504
c. What is an unnormalized relation? (2)
TURN OVER
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller VarsityC. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R50,00. You're not tied to anything after your purchase.
