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Information Systems 622 Memo
Information Systems
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Initiated By Academic Director Dr Muni Kooblal Document No Exams /02/ Authorised By Group Chief Executive Officer Mr J Ramnundlall Revision No 01/ Issuing Office Head Office – Main Campus CONTROLLED COPY Revision Date 02/10/ Document IS 622 Issue Date 02/10/
2 ND SEMESTER NATIONAL EXAMINATION
DURATION: 90 MINUTES MARKS: 70 DATE: 16 NOVEMBER 2017
EXAMINER: BLESSING HLATSWAYO MODERATOR: THABANI HADEBE
This paper consists of 4 questions and 6 pages including this page.
PLEASE NOTE THE FOLLOWING:
Ensure that you are writing the correct EXAMINATION paper, and that there are no missing pages.
You are obliged to enter your student details on the answer sheet. The answer sheet provided are the property of Richfield Graduate Institute of Technology (Pty) Ltd and all extra sheets must be handed to the invigilator before you leave the examination room.
If you are found copying or if there are any documents / study material in your possession, or writing on parts of your body, tissue, pencil case, desk etc. your answer sheet will be taken away from you and endorsed accordingly. Appropriate disciplinary measures will be taken against you for violating the code of conduct of Richfield Graduate Institute of Technology (Pty) Ltd Examinations Board. Therefore, if any of these materials are in your possession you are requested to hand these over to the invigilator before the official commencement of this paper.
The question paper consists of 2 sections.
Section A is online and is compulsory (QUESTION 1) Section B is compulsory Section C comprises of 3 questions and you are required to answer 2
SUGGESTED TIME REQUIRED TO ANSWER THIS QUESTION PAPER
NUMBERS QUESTIONS MARKS TIME IN MINUTES SECTION B: COMPULSORY 2 Question Two (Compulsory) 20 30 SECTION C: ANSWER TWO QUESTIONS FROM THIS SECTION 3 Question Three (Optional) 25 30 4 Question Four (Optional) 25 30 5 Question Five (Optional) 25 30 TOTAL 70 90
RICHFIELD GRADUATE INSTITUTE OF TECHNOLOGY (PTY) LTD
HIGHER EDUCATION AND TRAINING
FACULTY OF INFORMATION TECHNOLOGY
INFORMATION SYSTEMS 622
MARKING MEMO
Initiated By Academic Director Dr Muni Kooblal Document No Exams /02/ Authorised By Group Chief Executive Officer Mr J Ramnundlall Revision No 01/ Issuing Office Head Office – Main Campus CONTROLLED COPY Revision Date 02/10/ Document IS 622 Issue Date 02/10/
SECTION B (THIS SECTION IS COMPULSORY) (20 MARKS)
QUESTION TWO SHORT QUESTIONS (20 MARKS)
null2 What is Client/Server computing?
Distributed data – a client/server system in which the data and data manipulation layers are placed on the server(s), and other layers are placed on the clients. - Sometimes called two-tiered client/server computing. - Difference to file server systems is where the data manipulation commands are
executed. (2)
2 Discuss the characteristics of Client/Server system
- Sometimes called two-tiered client/server computing. - Difference to file server systems is where the data manipulation commands are executed. - Much less network traffic than file server systems because only the database requests and the results of those requests are transported across the network.
• Database integrity is easier to maintain. (4)
2 Differentiate between Fat server and Fat client
A fat client (thick client) design locates all or most of the application processing logic at the client. Fat client design is simpler and less expensive to develop A fat server is a type of server that provides most of the functionality to a client's machine within client/server computing architecture. It is like a standard core server that hosts and provides key network based applications, storage, processing, Internet access and other services
(4)
2 Discuss three types of maintenance activities
Three types of maintenance - Corrective maintenance-To fix errors - Adaptive maintenance-To add new capability and enhancements - Perfective maintenance-To improve efficiency
(6)
2 Describe only (4) FOUR principles for a user centered interface design
Design for the users and their tasks Be consistent Use simple and natural dialogue Reduce unnecessary mental effort by the user Provide adequate feedback Provide adequate navigation mechanisms Let the user drive Present information clearly Be helpful Reduce errors
(4)
SECTION C ( ANSWER TWO QUESTIONS FROM THIS SECTION) (50 MARKS)
Initiated By Academic Director Dr Muni Kooblal Document No Exams /02/ Authorised By Group Chief Executive Officer Mr J Ramnundlall Revision No 01/ Issuing Office Head Office – Main Campus CONTROLLED COPY Revision Date 02/10/ Document IS 622 Issue Date 02/10/
QUESTION FOUR OPTIONAL (25 MARKS)
CASE STUDY
4 Normalization and Entity Relationship Diagrams are two techniques for designing data
structures.
4.1 Describe these (2) TWO techniques in detail
An entity – relationship model (ER model) describes inter-related things of interest in a specific domain of knowledge. An ER model is composed of entity types (which classify the things of interest) and specifies relationships that can exist between instances of those entity types. In software engineering an ER model is commonly formed to represent things that a business needs to remember in order to perform business processes. Consequently, the ER model becomes an abstract data model that defines a data or information structure that can be implemented in a database, typically a relational database Normalization involves arranging attributes in relations based on dependencies between attributes, ensuring that the dependencies are properly enforced by database integrity constraints. Normalization is accomplished by applying some formal rules either by a process of synthesis or decomposition. Synthesis creates a normalized database design based on a known set of dependencies. Decomposition takes an existing (insufficiently normalized) database design and improves it
based on the known set of dependencies. (6)
4.1 What are the (2) TWO advantages and two disadvantages of these two
techniques? Advantages of an E-R Model: - Straightforward relation representation: Having designed an E-R diagram for a database application, the relational representation of the database model becomes relatively straightforward. - Easy conversion for E -R to other data model: Conversion from E-R diagram to a network or hierarchical data model can· easily be accomplished.
Disadvantages of an E-R Model: - No industry standard for notation: There is no industry standard notation for developing an E-R diagram. - Popular for high -level design: The E-R data model is especially popular for high level.
(4)
4 Blessing has decided to try the new computerized greenhouse climate control system in his
backyard nursery first before installing it in her remote nursery. She also considered two other methods.
Running both the new and current system at the same time for a month
Changing over to the new system in both nurseries all at once
4.2 Identify and explain the type of changeover method Blessing has decided to use.
There are three main methods used: phased implementation, direct
changeover and parallel running. Phased implementation: a staged (4)
Initiated By Academic Director Dr Muni Kooblal Document No Exams /02/ Authorised By Group Chief Executive Officer Mr J Ramnundlall Revision No 01/ Issuing Office Head Office – Main Campus CONTROLLED COPY Revision Date 02/10/ Document IS 622 Issue Date 02/10/
method whereby one part of the overall system that need changing is changed
4.2 Explain convincingly why this method is a better choice for Blessing than the other
two options/methods. NB: LECTURER ’ S DISCTRETION TO ANSWER THIS QUESTION BASED ON THE
ANSWER FOR 4.2 (6)
4 Define Distributed Relational Database and explain (2) TWO types of (base) Data
Distribution techniques. A distributed database is a database in which storage devices are not all attached to a common processor.[1] It may be stored in multiple computers, located in the same physical location; or may be dispersed over a network of interconnected computers. Unlike parallel systems, in which the processors are tightly coupled and constitute a single database system, a distributed database system consists of loosely coupled sites that share no physical components Two processes ensure that the distributed databases remain up-to-date and current: replication and duplication. Replication involves using specialized software that looks for changes in the distributive database. Once the changes have been identified, the replication process makes all the databases look the same. The replication process can be complex and time-consuming depending on the size and number of the distributed databases. This process can also require a lot of time and computer resources. Duplication, on the other hand, has less complexity. It basically identifies one database as a master and then duplicates that database. The duplication process is normally done at a set time after hours. This is to ensure that each distributed location has the same data. In the duplication process, users may change only the master database. This ensures that local data will not be overwritten.
(5)
QUESTION FIVE OPTIONAL (25 MARKS)
CASE STUDY
5 After Blessing’s system has been set up and working for about three months, a data
security company contacted Blessing about backing up her data. This company uses the Internet to transfer customer data to their storage facilities. The company has made the following three claims about their service.
Claim 1: Blessing would not need to worry about the backup, they would do it all for him. Claim 2: Blessing would always be able to access the backup. Claim 3: They would keep Blessing’s backup on a very secure site that is well away from the nurseries.
5.1 Using your knowledge on System Operation, Support, Cloud Computing Concepts
and Security, discuss the factors Blessing needs to investigate before signing the contract. Give reasons for your answer!
NB: Discuss according to per Claim 1, Claim 2, and Claim 3.
(25)
Information Systems 622 Memo
Course: Information Systems
University: Richfield Graduate Institute of Technology
