MIS480 2

Chapter-1.pdf

Home >Information Systems homework help >MIS480 2

Chapter -1 The Database Environment and Development Process

• The Database Environment and Development Process

• Chapter 1 (pp36-80)

It is essential you to read the text book. These slides represent a summary of what was presented in the class and summary of what is

covered in the book. Relying purely on the slides will not guarantee you will pass this course.

The Database Environment and Development Process

• Modern Database Management

• 13th Edition

• Jeffrey A. Hoffer, V. Ramesh,

• Heikki Topi

Course book:

Lesson Content

 Introduction to the Course & Tutor

 What is:  Data?  Information  Database?  DBMs?  Data model?  Metadata?  Enterprise Data Model?  Entity?  Relational Database?  ERP?  Data Warehouse?  SDLC?  Logical and Physical schema?

Get to know your tutor

• Dr. Syed Faizan Zaidi Joined AUM in August 2019.

 Assistant Professor

Ph.D. Information Systems in 2017 from London Metropolitan University, London, UK

• What is a Database? • The storage of data for the purpose of processing.

Databases can be: • Non-electronic: Hospital Filing Cabinet, University Student record

files, Bank Sales Receipt files..etc

• Electronic: MS Access: Hospital Patient Records, Oracle: Students Records, Cobol: Bank Sales Records…

Definitions p.36

• Metadata: data that describes the properties and context of user data.

• It is information about that data we are looking at.

Definitions p.41

Traditional File Processing

• Traditional File system: also called a file processing system, stores and manages data in one or more separate files. • Used Excel, notepad, or similar applications to store data.

• File processing design approach was well suited to mainframe hardware and batch input.

• File processing design is less common today.

• File processing can be more efficient and cost less than a DBMS in certain situations but it is less effective and prone to errors.

javascript:myWindow('file-oriented_system');

Traditional File Processing

• How are they different to Databases: • Database system: Organizing the data into tables, that form an

overall data structure.

• Compared to file processing, a database environment offers greater flexibility and efficiency.

Disadvantages of File Processing

• Program-Data Dependence • All programs maintain metadata for each file they

use

• Duplication of Data • Different systems/programs have separate copies

of the same data

• Limited Data Sharing • No centralized control of data

• Lengthy Development Times • Programmers must design their own file formats

• Excessive Program Maintenance • 80% of information systems budget

Elements of the Database Approach

• Data models • Enterprise Data Model–high-level entities and

relationships for the organization • Project Data Model –more detailed view, matching

data structure in database or data warehouse

• Entities • Noun form describing a person, place, object, event,

or concept. • Represent something we want to store in our

system. • Composed of attributes

• Relationships • Between entities • Usually one-to-many (1:M) or many-to-many (M:N)

• Relational Databases • Database method involving tables (relations)

representing entities and primary/foreign keys representing relationships.

Figure 1-5 Components of the Database Environment

Components of the Database Environment

• Database–storehouse of the data

• Repository–centralized storehouse of metadata

• Database Management System (DBMS) –software for managing the database

• Application Programs–software using the data

• System Developers–personnel (people) responsible for designing databases and software

• Data/Database Administrators–personnel (people) responsible for maintaining the database

• CASE Tools–computer-aided software engineering

• User Interface–text and graphical displays to users

• End Users–people who use the applications and databases

Two Approaches to Database and IS Development

• SDLC • System Development Life Cycle

• Detailed, well-planned development process

• Time-consuming, but comprehensive

• Long development cycle

• Prototyping • Rapid application development (RAD)

• Cursory attempt at conceptual data modeling

• Define database during development of initial prototype

• Repeat implementation and maintenance activities with new prototype versions

Systems Development Life Cycle (see also Figure 1-7)

Planning

Analysis

Physical Design

Implementation

Maintenance

Logical Design

Prototyping Database Methodology (Figure 1-8)

Database Schema

External Schema  User Views

 Subsets of Conceptual Schema

 Can be determined from business-function/data entity matrices

 DBA determines schema for different users

Conceptual Schema  E-R models–covered in Chapters 2 and 3

Internal Schema  Logical structures–covered in Chapter 4

 Physical structures–covered in Chapter 5

Different people

have different

views of the

database…these

are the external

schema

The internal

schema is the

underlying

design and

implementation

Figure 1-9 Three-schema architecture

Evolution of Database Systems

• Driven by four main objectives:

• Need for program-data independence  reduced maintenance

• Desire to manage more complex data types and structures

• Ease of data access for less technical personnel

• Need for more powerful decision support platforms

Evolution of Database Systems

The Range of Database Applications

• Personal databases

• Two-tier and N-tier Client/Server databases

• Enterprise applications • Enterprise resource planning (ERP) systems

• Data warehousing implementations

Keywords:

Data, Information, Database, DBMs, Data model, Metadata, Enterprise Data Model, Entity, Relational Database, ERP, Data Warehouse, SDLC, Prototyping, Logical and Physical schema, Repository, Database Management System (DBMS), Application Programs, System Developers, Data/Database Administrators, CASE Tools, User Interface–text, End Users, Database Schema, External Schema, Conceptual Schema, and Internal Schema, Evaluation of Database, Hierarchical Database model, Network Database Model, Relational database model, Object-oriented database model, Personal database, Two-tier database, and N- tier database