Data Models and Database Technologies: A Critical Comparison

This document provides a comprehensive analysis of various data models and database technologies, critically comparing their benefits and limitations. It explores hierarchical, relational, network, and object-oriented database models, examining their strengths and weaknesses. The document also delves into different database technologies, including file-based databases, multimedia databases, data warehousing, and cloud computing, highlighting their advantages and disadvantages. Finally, it analyzes two common approaches to database design: top-down and bottom-up methods, explaining their methodologies and applications. This document serves as a valuable resource for understanding the fundamental concepts of data models and database technologies, enabling informed decision-making in database design and implementation.

Contents
LO1 Understand data models and database technologies................................................................2
1.1 Critically compare different data models and schemas.........................................................2
1.2 Critically discuss the benefits and limitations of different database technologies................6
1.3 Analyze different approaches to database design..................................................................7
References:....................................................................................................................................10
Table of Figures:
Figure 1: Hierarchical Database Model...........................................................................................2
Figure 2: Relational Database Model..............................................................................................3
Figure 3: Network Database Model.................................................................................................4
Figure 4: Object-Oriented Database Model.....................................................................................4
Figure 5: Database Schema.............................................................................................................5
Figure 6: Top down Method............................................................................................................8
Figure 7: Bottom up method............................................................................................................8

LO1 Understand data models and database technologies
1.1 Critically compare different data models and schemas
A database has the logical structure which includes constraints and relationship to determine the
process of access stored the data. The database model is used to show this logical structure. The
database models are represented by the diagrams. Here is the various data models are discussed
below:
 Hierarchical database model
 Relational model
 Network mode006C
 Object-oriented database model
Hierarchical database model: this model is used organize the data into a tree structure in which
the record has root and single parent.it is used to store physical database.
Figure 1: Hierarchical Database Model
Source: (Studynight, 2018)
Advantages:
 Used to merge a large amount of data
 Improve data sharing technique and manage the relationship between information
 Each parent has many children
Disadvantages:
 The representation and navigation system is complex

 Data independence and not support many to many relationships (Lucidchart, 2018)
Relational Database Model: it is used to organized data in two-dimensional tables and
maintains the relationship by saving a common field. It was introduced in 1970 by E.F Codd.
Figure 2: Relational Database Model
Source: (Studynight, 2018)
Advantages:
 Data independence and promoted structured independence
 Does not define data relationship and use multi-level dataset between relationships
Disadvantages:
 Data anomalies
 Required tanning to use effectively and flexibly (Studytonight, 2018)
Network Model: organized data into graph form and have more than one parent. Easy to access
the data and use many to many relationships.

Figure 3: Network Database Model
Source: (Studynight, 2018)
Advantages:
 Support multi-parent and improve data access
 Promoted data integrity and many to many relationships
 Support large amount of data
Disadvantages:
 Require to predefined the data relationship
 More complex and complicated (Arora, 2018)
Object-Oriented Database Model: represent a database a group of objects and reuse the
software elements with their features and methods. It used two types:
Multimedia database and Hypertext database (Lucidchart, 2018)
Figure 4: Object-Oriented Database Model

Source: (ODBMS Facts, 2018)
Advantages:
 Enriched Modeling capabilities
 Extensibility
 Support schema evolution handle a large variety of data types
 Support for transactions and long-duration
Disadvantages:
 Lack of standards and experiences with the universal data model
 Lack of security and support for the view (Thakur, 2018)
Database Schemas: to represent the logical view of the database, a skeleton structure is used,
which is called database schema. It represents the data organization and relation with other
associated. It has basically three types: external or physical, conceptual and external.
 Internal or Physical: describe the physical structure of data which store on physical disk.
Also, call internal level.
 Conceptual or logical: define the structure of complete database with a user group. Also
known as a data model, represent the complete content of data and hide internal
description of physical storage.
 External: contain the data which view by the user and define the database segment which
requires for the user group to hide the database (Tutorialride, 2018).
Figure 5: Database Schema

Source: (tutorialspoint, 2018).
1.2 Critically discuss the benefits and limitations of different database technologies
The database is used to store the files and data on the server side or client side. It has various
types to discuss like, file-based, relational database and many more.
File-based database:
Advantages:
 Provide fast back-up and restore facility with data compactly
 Data stored in files by data retrieval technique and editing the information
 Remote access the computer system and sharing with multiple users
Disadvantages:
 Data redundancy and data incontinency
 Limited data sharing and difficult to access the data
 Problem with data integrity and atomicity
Multimedia database:
Advantages:
 User-friendly and multi-sensory
 Interactive and comprehensive with digitization
 Flexible and used in many industries like marketing, telecommunication
Disadvantages:
 Take too much time to compile the information
 Expensive to use and drawback with information overloaded
Data Warehousing: data warehousing is a collection of various types of data like, time-variant,
subject-oriented, integrated and nonvolatile, which used in support of decision-making process
of management.
Advantages:
 Competitive advantage with a huge return on investment
 The productivity of corporate decision makers is increased
 Cost-effective and potentially high returns after investment
Disadvantages:
 Increased user end demand and high demand for resources

 Necessary data not captured and data homogenization
 Data ownership and high maintenance (Thakur, 2018)
Cloud computing: a service which provides user to stores data online on internet and maintains,
backup and manages by remote from the user, is known as cloud computing.
Advantages:
 Usability: user drag and drop file between local storage and cloud
 Bandwidth: avoid email to instead and individual
 Accessibility: access file from anywhere by internet
 Disaster recovery: backup and recovery plan for the business
 Cost saving: reduce cost by using cloud storage
Disadvantages:
 Data security: data saved by remotely with the server. No other option is available for
security
 Software: download all software to manipulate your files on locally (bigdata-made
simple, 2018)
1.3 Analyze different approaches to database design
Basically, two approaches are used for database design, the top down and bottom up.
Top-down method: this approach starts from the normal or general and moves to special or
specific. We can say, start a plan with the general process with an idea which requires for a
system and move the process with using specific tasks with details of system interaction. The
complete process includes the various entities and attributes.

Figure 6: Top-down Method
Source: (Eaton, 2016)
Bottom-up method: this process is opposite of top-down method. It starts with specific and
moves to general. It identifies the data items and then groups them into data sets. It identifies the
attributes and entities (Database-Management, 2018).
Figure 7: Bottom-up method
Source: (Includehelp, 2018)
The entity and attributes are the key points of a relationship diagram which is known as ER
diagrams.
Entity: a real-world object which can be identifying easily like, a hospital database has doctors,
patients, departments as an entity. It a collection of same type data type.

Attributes: represented by properties known as attributes, the attributes have value like class,
name and many more. It has some types, simple, derived, composite and single-value attribute
and multi-value attribute (tutorialspoint, 2018)

References:
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http://ecomputernotes.com/database-system/adv-database/object-oriented-database-oodb
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