College of Computing and InformaticsAssignment 1
Deadline: Sunday 18/09/2022 @ 23:59
[Total Mark for this Assignment is 8]
Student Details:
Name:
CRN:
ID:
Instructions:
• You must submit two separate copies (one Word file and one PDF file) using the Assignment Template on
Blackboard via the allocated folder. These files must not be in compressed format.
• It is your responsibility to check and make sure that you have uploaded both the correct files.
• Zero mark will be given if you try to bypass the SafeAssign (e.g. misspell words, remove spaces between
words, hide characters, use different character sets, convert text into image or languages other than English
or any kind of manipulation).
• Email submission will not be accepted.
• You are advised to make your work clear and well-presented. This includes filling your information on the cover
page.
• You must use this template, failing which will result in zero mark.
• You MUST show all your work, and text must not be converted into an image, unless specified otherwise by
the question.
• Late submission will result in ZERO mark.
• The work should be your own, copying from students or other resources will result in ZERO mark.
• Use Times New Roman font for all your answers.
Question One
Pg. 01
Learning
Outcome(s):
Question One
CLO1
Discuss any four types of Database Models?
Explain database
concepts,
systems, and
architectures
involved in
database
development.
2 Marks
Question Two
Pg. 02
Learning
Outcome(s):
CLO1
Explain database
concepts,
systems, and
architectures
involved in
database
development.
Question Two
2 Marks
Compare between the Two-Tier Client-Server DBMS Architecture and Three
Tier Client-Server DBMS Architecture.
Question Three
Pg. 03
Learning
Outcome(s):
CLO1
Explain database
concepts,
systems, and
architectures
involved in
database
development.
Question Three
2 Marks
What are the drawbacks of using file system over database management
system?
Question Four
Pg. 04
Learning
Outcome(s):
CLO1
Explain database
concepts,
systems, and
architectures
involved in
database
development.
Question Four
2 Marks
Describe the features of a Database Management System (DBMS) and its use
within an organization.
College of Computing and Informatics
Assignment 1
Deadline: Sunday 18/09/2022 @ 23:59
[Total Mark for this Assignment is 8]
Student Details:
Name:
CRN:
ID:
Instructions:
• You must submit two separate copies (one Word file and one PDF file) using the Assignment Template on
Blackboard via the allocated folder. These files must not be in compressed format.
• It is your responsibility to check and make sure that you have uploaded both the correct files.
• Zero mark will be given if you try to bypass the SafeAssign (e.g. misspell words, remove spaces between
words, hide characters, use different character sets, convert text into image or languages other than English
or any kind of manipulation).
• Email submission will not be accepted.
• You are advised to make your work clear and well-presented. This includes filling your information on the cover
page.
• You must use this template, failing which will result in zero mark.
• You MUST show all your work, and text must not be converted into an image, unless specified otherwise by
the question.
• Late submission will result in ZERO mark.
• The work should be your own, copying from students or other resources will result in ZERO mark.
• Use Times New Roman font for all your answers.
Question One
Pg. 01
Learning
Outcome(s):
CLO1
Explain database
concepts,
systems, and
architectures
involved in
database
development.
Question One
2 Marks
Discuss any four types of Database Models?
Answer 1
1) Relational Model
Relational Model organizes data into two dimensional arrays known as relations(tables)
and each relation consists of rows and columns. Another major characteristic of
relational model is that of keys, designated columns in a relation used to order data or
establish relations.
2)Object Oriented Model
Object Model aims to reduce the overhead of converting information representation in
the database to an application specific representation. Unlike a traditional database, an
object model allows for data persistence and storage by storing objects in the databases.
The relationships between various objects are inherent in the structure of the objects.
This is mainly used for complex data structures such as 2D and 3D graphics which must
otherwise be flattened before storage in a relational database.
3) Hierarchical model
Hierarchical model contains data organized into a tree-like structure.
This supports parent-child relationships between data similar to a tree data structure
where object types are represented by nodes and their relationships are represented by
arcs. This model is restrictive in that it only allows one to many relationship (a parent
can have many children but a child can only have one parent) An example of this is Jump
to search IBM’s Information Management System (IMS), which is a joint hierarchical
database with extensive transaction processing capabilities.
4) Network Model
Network Model is similar to the hierarchical model in representation of data but allows
for greater flexibility in data access as it supports many to may relationships.
Question One
Pg. 02
Answer 1
Relational model
The most common model, the relational model sorts data into tables, also known as
relations, each of which consists of columns and rows. Each column lists an attribute of
the entity in question, such as price, zip code, or birth date. Together, the attributes in a
relation are called a domain. A particular attribute or combination of attributes is chosen
as a primary key that can be referred to in other tables, when it’s called a foreign
key.Each row, also called a tuple, includes data about a specific instance of the entity in
question, such as a particular employee.
Hierarchical model
The hierarchical model organizes data into a tree-like structure, where each record has
a single parent or root. Sibling records are sorted in a particular order. That order is
used as the physical order for storing the database. This model is good for describing
many real-world relationships.
Network model
The network model builds on the hierarchical model by allowing many-to-many
relationships between linked records, implying multiple parent records. Based on
mathematical set theory, the model is constructed with sets of related records. Each set
consists of one owner or parent record and one or more member or child records. A
record can be a member or child in multiple sets, allowing this model to convey complex
relationships.It was most popular in the 70s after it was formally defined by the
Conference on Data Systems Languages (CODASYL).
Question One
Pg. 03
Object-oriented database model
This model defines a database as a collection of objects, or reusable software elements,
with associated features and methods. There are several kinds of object-oriented
databases:
A multimedia database incorporates media, such as images, that could not be stored in
a relational database.
A hypertext database allows any object to link to any other object. It’s useful for
organizing lots of disparate data, but it’s not ideal for numerical analysis.
The object-oriented database model is the best known post-relational database model,
since it incorporates tables, but isn’t limited to tables. Such models are also known as
hybrid database models.
Question Two
Pg. 04
Learning
Outcome(s):
CLO1
Question Two
2 Marks
Compare between the Two-Tier Client-Server DBMS Architecture and Three
Tier Client-Server DBMS Architecture.
Explain database
concepts,
Answer 1
systems, and
Two Tier
three Tier
architectures
the application logic is either buried
inside the user interface on the client or
within the database on the server (or
both).
the application logic or process
resides in the middle-tier, it is
separated from the data and the
user interface.
is client server application. .
is web based application
divided into two layers: Client
Application (Client Tier) and Database
(Data Tier).
Three layers in three tier
architecture are: Client layer,
Business layer and Data layer.
Direct communication takes place
between client and server.
There is an intermediate between
client and server known as
application server.
systems are less scalable and robust.3tier
systems are more scalable and
robust, as requests can be load
balanced between servers.
is less secured as client can engage the
database directly
.Highly secured as client is not
allowed to engage the database
directly.
involved in
database
development.
Question Two
Pg. 05
Answer 2
1
2
3
4
Two-Tier Database
Architecture
It is a Client-Server Architecture.
In two-tier, the application logic is
either buried inside the user
interface on the client or within the
database on the server (or both).
Two-tier architecture consists of
two layers : Client Tier and
Database (Data Tier).
It is easy to build and maintain.
5 Two-tier architecture runs slower.
6 It is less secured as client can
communicate with database
directly.
7 It results in performance loss
whenever the users increase
rapidly.
8 Example – Contact Management
System created using MS-Access
or Railway Reservation System,
etc.
Three-Tier Database
Architecture
It is a Web-based application.
In three-tier, the application logic
or process resides in the middletier, it is separated from the data
and the user interface.
Three-tier architecture consists of
three layers : Client Layer,
Business Layer and Data Layer.
It is complex to build and
maintain.
Three-tier architecture runs
faster.
It is secured as client is not
allowed to communicate with
database directly.
It results in performance loss
whenever the system is run on
Internet but gives more
performance than two-tier
architecture.
Example – Designing registration
form which contains text box,
label, button or a large website
on the Internet, etc.
Question Three
Pg. 06
Learning
Outcome(s):
Question Three
2 Marks
What are the drawbacks of using file system over database management
CLO1
system?
Explain database
Answer 1
concepts,
systems, and
architectures
involved in
database
development.
1- Data redundancy and inconsistency. different programmers making
the files since a long time moreover the same information duplication in
different files and and this duplication needs high storage and cost access
and it may lead multiple file format and inconsistency.
2- Difficulty in accessing data.: if i need names of student there living in
particular city there more difficult either search all students manually or I
need to create a new program to carry out each new task.
3- Data isolation.: because the data is sparse in different files and the
files in many formats and write new program to get data is more difficult.
4- Integrity problems.: The data stored in the database should satisfy
some types of certain limitations like( account balance >0) and can be
difficult to add new constraints or change the previously existing
constraints.
5- Atomicity problems.: Computer system exposed to the failure of such
a device must be in the case of system failure For example, when you
drag the balance either the process complete or are not taken to withdraw
the balance if the system fails and this gets in the file system.
7- Security problems.: must all user can access to some data not all
example student not access to data for teachers but in file systems have
security problems.
Question Three
Pg. 07
Answer 2
•
•
•
•
Data Redundancy: It’s possible that the same data is duplicated in
many files. This results in data redundancy and memory waste.
Data Inconsistency: Due to data redundancy, it’s probable that data
won’t be consistent.
Accessing Data Is Difficult: It’s not simple to get data out of a file
management system. It isn’t as convenient as it should be. When a
user needs to access information, they must run specialized
software. For example, we have a graphical user interface in our
computers installed using which we access the files stored.
Limited Data Sharing: Data is dispersed across multiple files.
Moreover, separate files may have different formats, and these files
may be housed in several directories belonging to various
departments. As a result of this data segregation, data sharing
between applications is challenging.
Question Four
Pg. 08
Learning
Outcome(s):
CLO1
Explain database
concepts,
systems, and
architectures
involved in
database
development.
Question Four
2 Marks
Describe the features of a Database Management System (DBMS) and its use
within an organization.
Answer 1
1. Minimum repetition and redundancy: In a database there are high chances of data
duplication due to the presence of many users. DBMS resolves this issue by building a
repository where all the data are stored and can be accessed by multiple users.
2. Databases of big corporations or companies can only be managed by a database
management system. Database management system offers data protection and features
like recovery and backup for easy recording and retrieval of data.
3. Enhanced security: Database management systems offer enhanced security by
restricting public access. It can only be accessed by a database administrator or the
concerned head of the department.
4. Multiple user access: Database is designed in such a way that it can be accessed by
multiple users who can work on different sections of the databases at a time without
interrupting the flow of work.
5. Provides multiple views of the data: Database management system allows the users to
access multiple views of the data present in the database. For e.g an HR personnel can
check the database for processing the data of the employee, while at the same time an
employee can use the database to access resources related to payslip, attendance, etc.
6. Permanent storage of data: Data stored in a database will remain stored permanently
until and unless it is deleted from the system manually. Even in cases of accidental
deletion of data, the database system has a robust recovery system which allows
recovery of deleted data.
Question Four
Pg. 09
Answer 1
A DBMS is a tool that can manage data within the database by maintaining data integrity.
There are several features such as
•
you can delete, alter and update data within the database.
•
It provides a way to structure the data by storing it into tabular form.
•
It enables to enforce integrity rules such as referential integrity by making relations
between two tables.
•
It provides security features. It has support for query language that is SQL by which
operation on database can be performed.
•
DBMS used to store record and data within organization. A large amount of data can be
stored in DBMS in a structured format such as in the form of TABLE and different records
belonging to different categories will be stored in different tables. Such as an example
employee records, salary details, transactions and product details.