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Electronic Data Processing (EDP)

Mr.Anjan Mahanta LCCT,International Studies Program

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Course Outline Managing Files : Basic Concepts

How data is Organized: The Data Storage Hierarchy Types of Files

Database Management Systems Four Types of Database Access

Database Models Hierarchical Database Network Database Relational Database Object-Oriented Database

Features of Database Management System Data Dictionary Utilities

Databases and the New Economy E-Commerce Data Mining

The Ethics of Using Storage and Databases Manipulation of Sound, Photos, Video & Television Accuracy and Completeness

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Grade

Sub-Test Quiz Mid-Term Final Attendance Homeroom

20% 10% 25% 25% 10% 10%

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Unit 1 Managing Files: Basic Concepts

Data can be grouped into categories

The data storage hierarchy consists of the levels of data stored in a computer

Bits

Bytes

Fields

Records

Files

Databases

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Unit 1 Managing Files: Basic Concepts

Characters: A character (byte) is a letter, number, or special character

Examples : A, B, C, 1, 2, 3, #, $, %

Field: A field is a unit of data consisting of one or more characters (bytes).

Examples: your name, address

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Unit 1 Managing Files: Basic Concepts

Record: A record is a collection of related fields.

Examples : Student code, name and address

File: A file is a collection of related records.

Examples: file of students grade information

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Unit 1 Managing Files: Basic Concepts

Database: is an organized collection of related files.

Examples : Student information

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Unit 1 Managing Files: Basic Concepts

Type of data Contains Example

Database Several files Student database

Address, Grade, Fee

File Several records Name Address

Jack Bangkok

Rocky Chiangmai

Record Several fields Name Address

Jack Bangkok

Field Several Characters Name

Jack

Character Bits (0 or 1) S

1110 0010

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Example from MS-Access

Student Address File

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Exercise - 1

What are databases?

Write five examples of databases. Design one database in details showing

fields and records.

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Primary Key Field

A key field uniquely identify a record

It helps to easily process the database

Example:

student_code is a key field in a student database

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Types of Files

File is the collection of data or information

The user gives a name to each file to save for future use

The file names have an extension name.

Example –

Microsoft Word .doc

Microsoft Excel .xls

Microsoft PowerPoint .ppt

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Types of Files

There are many types of files but the most important types are –

Program files

Data files

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Program Files

Program files are files containing software instructions.

The program files are instruction files written by a program for a particular application

They have a file extension. For example –

.bas for BASIC, .pas for Pascal or .jav for Java

For the processor to use a source file at first it must be converted to an executable file,

.exe file

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Data files

Data files are files that contain data – words, numbers, pictures, sounds, etc.

Data files are created by the users.

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Other types of files

ASCII files .txt

Image(graphic files) .bmp, .gif, .jpg, .pcx, .tif, .wmf

Audio files .wav, .mid, .mp3

Animation/video files .avi, .mpg

Web files .html, .htm, .xml, .php, .asp

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Exercise

What is a primary key?

What is a file?

What are the types of file?

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Types of Data Files

Master file: The master files are updated periodically

Transaction file: The transaction file is a temporary file that holds all changes to be made to the master file: additions, deletions and updations

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Example

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Data Access Methods

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Data Access Methods

Sequential Storage: means that data is stored and retrieved in sequence, in alphabetically – ascending or descending order

Example: A tape cassette

Advantage: less expensive

Disadvantage: file searching is slow

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Example

Sequential Search

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Data Access Methods

Direct Access Storage: means that computer can go directly to the information you want. It is also known as random.

Example: A CD Player

Advantage: faster

Disadvantage: more expensive

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Exercise

1. What is a master file?

2. What is a transaction file?

3. What is sequential storage?

4. What is direct access storage?

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Offline Storage

Offline storage means that data is not in the direct control on the CPU. It maybe saved in a CD.

The data has to be loaded onto an input device.

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Online Storage

Online storage means that data is

immediately accessible by the CPU.

You need not wait for a CD.

Storage is on the disk (direct access storage)

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Database Management Systems DBMS

A database is an organized collection of related files

There are many types of databases

To manage the information a database management system is used

The DBMS is a program that controls the structure of a database and access to the data

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Advantages of DBMS

File Sharing users can share files

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Advantages of DBMS

Reduced data redundancy prevent duplication

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Advantages of DBMS

Improved data integrity accurate and up to date

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Advantages of DBMS

Increased security data can be secured by the use of passwords

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Exercise

What is a Database Management System?

What are the advantages of DBMS?

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Types of Database Access

Individual database

used by one person

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Types of Database Access

Shared database

shared by many people in one location

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Types of Database Access

Distributed database

shared by many people in many locations

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Types of Database Access

Public databank information for the public

Yahoo

Google

Law

Shopping

News

Games

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DBA

The Database Administrator (DBA) coordinates all related activities and needs for an organization’s database.

The DBA determines user access privileges, sets standards.

The DBA is responsible for system back up and recovery.

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Exercise

Describe the four types of databases.

What does a database administrator do?

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Database Models Hierarchical Database

In a hierarchical database, fields or records are arranged in related groups resembling a family tree, with child (lower-level) records subordinate to parent (higher-level) records.

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Database Models

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Database Models

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Database Models

Network Database

A network database is similar to a hierarchical database, but each child record can have more than one parent record.

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Database Models

Relational Database

A relational database relates, or connects, data in different files through the use of a key field, or common data element.

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Database Models

Relational Database

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Database Models

Relational Database

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Structured Query Language SQL

SQL is the standard language used to

Create

Add

Delete

Update

relational databases

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Structured Query Language SQL

Example

1. Select * from student

2. Select * from student where firstname=“Andrew”

3. Select * from student where grade > 2

4. Select * from student where age > 18

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Object Oriented Database

An object oriented database uses objects. An object consists of graphics, audio and video.

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Exercise

What are the four models of database organization?

What is SQL?

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Application Service Provider ASP

ASPs allow users to subscribe to various software applications over the Internet.

Example in Thailand ADSL

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DBMS Components

Data Dictionary

It is a file that stores the definitions of the structure of data used in the database.

Example:

Keyword Description Room_Id The room numbers of the hotel

Check_In The date when the guest check into the hotel

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DBMS Components

Utilities

The DBMS utilities maintains the database by creating, editing and monitoring data input

Example

MS-ACCESS

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DBMS Components

Report Generator

It is a program that creates onscreen or printed document

Example

MS-ACCESS

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DBMS Components

Access Security

It specifies user access privileges

Example

MySQL

ORACLE

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Exercise

1.What is data dictionary?

2.What do DBMS utilities do?

3.How does access security work?

4.Explain the four types of system recovery.

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DBMS Components

System / Data Recovery It enables contents of database to be recovered

after system failure

Types of Data Recovery Mirroring – two copies in different locations

Reprocessing – redoing the processing from a known past point

Rollforward – a variant on reprocessing

Rollback – undoing unwanted changes

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E-Commerce

E-Commerce or Electronic Commerce

is the buying and selling of products and services through computer networks

Amazon.com, eBay, Priceline.com are the best example for e-commerce or online shopping

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Process of e-commerce

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Process of e-commerce

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Data Mining

Data mining (DM) is the computer-assisted process of sifting through and analyzing vast amounts of data

It is used to extract meaning and discover new knowledge

It’s main purpose is to describe past trends and predict future trends

It can be used to learn customer, marketing, production and financial data

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Data Mining

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Data Mining Process

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Data Mining Process

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Applications of Data mining

Marketing

Health

Science

B2B In a business to business (B2B) system, a

business sells to other businesses, using the Internet to cut transaction costs and increase efficiencies.

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B2B Systems

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B2B Systems

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Exercise

What is data mining, and how is it used?

What is B2B system?

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The Ethics of Using Databases

Morphing – transforming one image to another

Manipulation of sound With the help of new technology a song can be recorded by

the singers at different times and places

Manipulation of photos Editing images

Manipulation of Videos & Television Graphics and animation

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The Ethics of Using Databases

Accuracy and Completeness

Public databanks Nexis/Lexis

Matters of Privacy

Privacy is the right of people not to reveal information about themselves

Monopolizing Information