Chapter 13Databases and Information Management

Explain why data and information are important to an

organization

Identify file maintenance techniques

Differentiate between the file processing and database

approaches

Discuss the advantages of using a database management

system (DBMS)

Describe characteristics of relational and object-oriented

databases

Explain how to use a query language

Understand how Web databases work

Discuss the responsibilities of the database analysts and

administrators

Identify the qualities of valuable information

Describe the various types of information systems

Understand the concept of a data warehouse

Chapter 13 Objectives

Next

p. 13.2

Data and Information

What is data? A collection of

raw unprocessed facts, figures, and symbols

p. 13.2 Fig. 13-1

Next

Data and Information

What is information?

Data that is organized, meaningful, and useful

p. 13.2 Fig. 13-1

Next

Data and Information

How are data and information related?

Computers process data into information

p. 13.2 Fig. 13-1

Next

Data and Information

What is a database? Includes a collection of data

organized so you can access, retrieve, and use the data

Database software allows you to • Create a computerized database• Add, change, and delete data• Sort and retrieve data from the database• Create forms and reports for the data in

the database Database software also called a database

management system (DBMS)p. 13.2

Next

Data and Information

What is data integrity? The degree to which

data is correct When a database

contains errors, it loses integrity

Very important because computers and people use information to make decisions and take actions

p. 13.3

Next

Garbage in, garbage out

(GIGO)

You cannot create correct information

from data that is incorrect

The Hierarchy of Data

What is a field? A combination of one or more

characters The smallest unit of data a

user accesses A field name uniquely

identifies each field

p. 13.4 Fig. 13-3

Next

Character

A number (4), letter (R), punctuation

mark (?), or other symbol (&)

fields

Object – picture, audio, video, or a document created in other applications such as word processing or spreadsheet

Hyperlink – Web address that links to a document or a Web page

Yes/No – only the values Yes or No

Memo – lengthy text entries

Date – month, day, year, and sometimes time information

Currency – dollar and cent amounts or numbers containing decimal values

Numeric – numbers only

Text – letters, numbers, or special characters

The Hierarchy of Data

What are characteristics of a field? Data type

• Specifies the kind of data a field can contain

• Specifies how the field is used

Field size• Defines the

maximum number of characters a field can contain

p. 13.5

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The Hierarchy of Data

What is a record? A group of related fields

p. 13.5 Fig. 13-2

Next

records

field names

maximum characters in Rating

fieldkey field

A field that uniquely identifies each record

in a fileAlso called a primary

key

The Hierarchy of Data

What is a data file? Also called a file A collection of related records stored on a disk Each record in the file contains the same fields Each field contains different data

p. 13.5 Fig. 13-3

Next

Sample Customer File

fields

records

Maintaining Data

What is file maintenance?

Also called data maintenance

The procedures that keep data current

p. 13.6

Next

Adding records

Changing records

Deleting records

Maintaining Data

How are records added? A clerk uses a Customer

Maintenance program to add a new record

The clerk enters the data for each field of the record

The clerk takes a photograph with a digital camera and confirms the data is correct

The clerk then adds the record to the database file

p. 13.6 Fig. 13-4

Next

Maintaining Data

How are records changed? The clerk starts the

Customer Maintenance program

The clerk displays the customer record on the screen

The clerk makes the corrections

The clerk verifies the data and then clicks the Save button to change the record in the Customer file

p. 13.6 Fig. 13-5

Next

Records changed to correct inaccurate data

or to update old data with new data

Maintaining Data

How is data deleted? The clerk starts

the Customer Maintenance program

The clerk displays the customer record on the screen

The clerk confirms the correct customer record displays

The clerk clicks the Delete Record button

p. 13.8 Fig. 13-6

Next

A record can be flagged, or marked, so

the program will not process it again

Maintaining Data

What is validation? The process of comparing data to a set of rules or

values to find out if the data is correct A validity check analyzes entered data to help ensure

that it is correct Validity

checks are also called validation rules

p. 13.9 Fig. 13-7

Next

Click to view Web Linkthen click Validity Checks

Completeness check

Verifies a required field contains data

Numeric check

Ensures that you enter only numeric

data into a field

Alphabetic check

Ensures that you enter only

alphabetic data into a field

Check digit

Confirms the accuracy of a

primary key value

Consistency check

Tests if the data in two or more

associated fields is logical

Range check

Determines whether a number

is within a specified range

Maintaining Data

What are the types of validity checks?

p. 13.9

Next

Maintaining Data

What is an example of a completeness check? If you do not fill in a

required field, an error message usually displays stating which required fields you left blank

p. 13.10 Fig. 13-8

Next

Maintaining Data

A number(s) or character(s) that is appended to or inserted into a primary key value

Used to confirm the accuracy of a primary key value

When the primary key is entered, the program applies the check digit formula to determine if the primary key is valid

p. 13.10

Next

Check digit = 8

Calculate total of digits again:

1 + 7 = 8

Resulting primary key: 13678

Calculate total of digits:

1 + 3 + 6 + 7 = 17

Initial primary key: 1367

What is a check digit?

File Processing Versus Databases

What is a file processing system? Each department or area within an organization has its

own set of files Records in

one file often do not relate to the records in any other file

p. 13.11 Fig. 13-9

Next

File Processing Versus Databases

What are the weaknesses of a file processing system?

p. 13.11

Next

data redundancy

• The files often store the same fields in multiple files

• Wastes resources such as storage space and people’s time

• Requires a larger storage capacity

• Compromises data integrity

isolated data

• It is often difficult to access data stored in many files across several departments

• Sharing data from multiple, separate files is often a complicated procedure

File Processing Versus Databases

What is the database approach? Many programs

and users can share the data in the database

Secures the data so only authorized users can access certain data items

p. 13.12 Fig. 13-10

Next

Front end

A program that typically has a more

user-friendly interface than the DBMS

Back end

The application that supports the

front end

Reduced data redundancy

File Processing Versus Databases

What are the strengths of the database approach?

p. 13.13

Next

Improved data integrity

Shared data

Reduced development time

Easier reporting

File Processing Versus Databases

How do a database application and a file processing application differ in the way they might store data?

p. 13.13 Fig. 13-11

Next

File processing example

Database example

Database Management SystemsWhat is a database management system (DBMS)?

Software that allows you to create, access, and manage a database

Available for many sizes and types of computers

Next

Click to view Web Linkthen click Database Management Systems

Click to viewanimation

p. 13.14 Fig. 13-12

Database Management SystemsWhat is a data dictionary?

Also called a repository

Contains data about each file in the database and each field within those files

Sometimes called metadata because it contains data about data

p. 13.15 Fig. 13-13

Next

Click to view Web Linkthen click Data Dictionary

Database Management SystemsWhat is a default value for a field?

A value that the DBMS initially displays in a field

Data dictionary allows you to specify a default value for a field

p. 13.15

Next

Database Management SystemsWhat is a query?

A request for specific data from the database

Four commonly used methods to access data

p. 13.15

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Query language

Query by example

Form

Report generator

Click to viewanimation

Database Management SystemsWhat is a query language?

Consists of simple, English-like statements that allow you to specify the data to display, print, or store

p. 13.16 Fig. 13-14

Next

wizard for querying the databasequery

results

Database Management SystemsWhat is a query by example (QBE)?

The program retrieves records that match criteria you enter in the form fields

Uses a graphical user interface

p. 13.17 Fig. 13-15

Next

query by example screen

query results

Database Management SystemsWhat is a form?

Sometimes called a data entry form A window on the screen that provides areas for entering

or changing data in a database

p. 13. Fig. 13-16

Next

Database Management SystemsWhat is an electronic form?

Also called an e-form

A form that sends entered data across a network or the Internet

Typically uses a means to secure the data while it is transported

p. 13.18 Fig. 13-17

Next

Database Management SystemsWhat is a report generator?

Also called a report writer

Allows you to design a report on the screen, retrieve data into the report design, and then display or print the report

Usually allows you to format page numbers and dates; titles and column headings; subtotals and totals; and fonts, font sizes, color, and shading

p. 13. 19Fig. 13-18

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Full-update privileges

User can retrieve and change the data

Database Management Systems

A DBMS provides means to make certain only authorized users can access data at permitted times

Most DBMSs allow you to identify different levels of access privileges for each field in the database

p. 13.19

Next

Click to view video

Read-only privileges

User can retrieve data, but cannot change it

Access privileges

Define the activities that a specific user or group of users

can perform

What is data security?

Database Management SystemsHow should you protect data stored in a

database? A DBMS

provides a variety of techniques to restore a database to a usable form in case it is damaged or destroyed

p. 13.20

Next

Backup

On a regular basis, make a backup, or copy, of the entire

database

Some DBMSs have their own backup utilities

before image: a copy of the customer record prior to the change

after image: a copy of the customer record after the change

Database Management SystemsWhat is a log?

A listing of activities that change the contents of the database

For every change the DBMS places three items in the log

p. 13.20 Fig. 13-18

Next

the actual change of data

Database Management SystemsWhat is a recovery utility?

Uses the logs and/or backups to restore a database when it is damaged or destroyed

Restores the database using rollback and rollforward techniques

p. 13.20

Next

Rollback

Also called backward recovery

The DBMS uses the log to undo any changes made to the database

during a certain period of time

Rollforward

Also called forward recovery

The DBMS uses the log to re-enter changes

made to the database since the last save or

backup

Relational, Object-Oriented and Multidimensional DatabasesWhat is a data model?

Every database and DBMS is based on a specific data model

Consists of rules and standards that define how the database organizes data

Defines how users view the organization of the data

Three popular data models in use today• Object-relational

databases combine features of the relational and object-oriented data models

p. 13.21 Fig. 13-20

Next

Relational Databases

Multidimensional Databases

Object-oriented Databases

Object-relational Databases

Click to viewanimation

Company on the Cutting Edge

Oracle products are used by 96 percent of the Fortune 500 companies

In 1977, Larry Ellison co-founded Oracle

Now the world’s leading supplier of software for e-business

Its database product, also named Oracle, is the world’s leading database software

p. 13.21

Next

Click to view Web Linkthen click Oracle Corporation

Click to view video

Technology Trailblazer

E. F. Codd In 1970, he created the

relational approach to database management

Codd’s model continues to serve as the de facto standard on which large and small databases are structured

p. 13.22

Next

Click to view Web Linkthen click E. F. Codd

Relational, Object-Oriented, and Multidimensional DatabasesWhat is a relational database?

Stores data in tables that consist of rows and columns

Each row has a primary key and each column has a unique name

A relational database uses terms different from a file processing environment

p. 13.22 Fig. 13-21

Next

Data terminology

Click to view Web Linkthen click Relational Databases

Relational, Object-Oriented, and Multidimensional DatabasesWhat is a relationship?

A connection within the data

Relationships stored as part of a relational database

Normalization is a process designed to make sure the data within the relations (tables) contains the least amount of duplication

p. 13.22 Fig. 13-22

Next

tabletable

rowrow

columncolumn

relationshipsrelationships

Relational, Object-Oriented, and Multidimensional DatabasesWhat is relational algebra?

Uses variables and operations to build new relations

Used to manipulate and retrieve data

Variables are the tables, rows, and columns of the database

p. 13.24

Next

Projection operation

Retrieves data from columns (fields)

Selection operation

Retrieves data from certain rows (records)

Join operation

Combines the data from two or more tables

projection operation results

Relational, Object-Oriented, and Multidimensional DatabasesWhat is an example of a projection

operation? The operation extracts data from a column (field)

p. 13.24 Fig. 13-23

Next

all rows and columns in Movie table

Relational, Object-Oriented, and Multidimensional DatabasesWhat is an example of a selection

operation? The operation extracts data from a row (record)

p. 13.24 Fig. 13-23

Next

all rows and columns in Movie table

selection operation results

Relational, Object-Oriented, and Multidimensional DatabasesWhat is an example of a combined

projection and selection operation? The operation extracts data from a column (field)

p. 13.24 Fig. 13-23

Next

all rows and columns in Movie table

projection and selection operation results

Rental TableMovie Table

Relational, Object-Oriented, and Multidimensional DatabasesWhat is an example of a join operation?

Combines the data from two or more tables using a common column

p. 13.24 Fig. 13-24

Next

Rental Table and Movie Table Joined on Movie ID Column

Relational, Object-Oriented, and Multidimensional DatabasesWhat is Structured Query Language (SQL)?

A query language that allows you to manage, update, and retrieve data

Uses relational algebra Has special keywords and rules that you include in SQL

statements

p. 13.25 Fig. 13-25

Next

selection operation

join operation

projection operationClick to view Web Linkthen click SQL

Relational, Object-Oriented, and Multidimensional DatabasesWhat is an object-oriented database

(OODB)?

Stores data in objects

Advantages• Can store more

types of data• Can access the

data faster

p. 13.26

Next

Object

An item that can contain both data and the activities that read

or process the data

Object query language (OQL)

Query language used to manipulate and retrieve object-oriented and object-relational

data

Click to view Web Linkthen click Object-Oriented Databases

Relational, Object-Oriented, and Multidimensional Databases

p. 13.26

Hypertext databases

Contain text links to other documents

Hypermedia databases

Contain text, graphics, video, and sound

What are examples of applications appropriate for an OODB?

Web databases

Link to an e-form on a Web page

Multimedia databases

Store images, audio clips, and/or video clips

Groupware databases

Store documents such as schedules, calendars, manuals,

memos, and reports

Computer-aided design (CAD) databases

Store data about engineering, architectural, and scientific

designs

Next

Relational, Object-Oriented, and Multidimensional Databases

To display information about a particular artifact, you enter its description in the Keywords text box

p. 13.26 Fig. 13-26

Next

Keywords text box

Keywords text box

What is an example of a hypermedia database?

Relational, Object-Oriented, and Multidimensional DatabasesWhat is a multidimensional database

(MDDB)? Stores data in

dimensions Can store more

than two dimensions of data

Sometimes known as a hypercube

p. 13.27

Next

Advantage

It can consolidate data much faster than a relational

databaseClick to view Web Linkthen click Multidimensional Databases

Web Databases

A database of information that can be accessed through the Web

A vast amount of information available through the Web

p. 13.28 Fig. 13-27

Next

What is a Web database?

Click to view video

Company on the Cutting Edge

A free, national directory of U.S. residential information Among the 50 most popular Internet sites Contains telephone number and

address directories for nearly 100-million people, 12-million businesses, and 4-million U.S. e-mail addresses

p. 13.28

Next

Click to view Web Linkthen click Switchboard

Database server

A computer that stores and

provides access to the database

Step 1: The browser sends your search text to the Web server.

Step 1

Step 2: The Web server sends the search text through a CGI program to the database. The database retrieves the Web page that contains the search text and sends it through the CGI program back to the Web server.

Step 1

Step 2

CGI (Common Gateway Interface) script

A type of program that manages the sending and receiving of data between

the front end and the database server

Step 3: The Web server sends the Web page to the browser.

Step 1

Step 2

Step 3

Web Databases

How can you access a Web database?

p. 13.28 Fig. 13-28

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Database Administration

What is the role of the database analyst and administrator?

Responsible for managing and coordinating all database activities

In small companies, one person often is both the database analyst and administrator

p. 13.30

Next

Database analyst (DA)

Also called data modeler

Focuses on the meaning and usage of data

Decides the proper placement of fields, defines relationships among data, and

identifies users’ access privileges

Database administrator (DBA)

Creates and maintains the data dictionary, manages security of the database, monitors the performance of the

database, and checks backup and recovery procedures

Click to view Web Linkthen click Database Administrator

Database Administration

What is the role of the employee as a user? Employee should learn how to utilize the data in the

database Must take an active role in identifying new data for the

database Take part in designing

the database that will help achieve company’s overall goals

p. 13.30

Next

Database Administration

What are guidelines for developing a database?

p. 13.30 Fig. 13-29

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Qualities of Valuable Information

What are the qualities of valuable information? Characteristics of information make it valuable

p. 13.30

Next

Accurate information

Verifiable

Organized information

Useful information

Cost-effective information

Timely information

Accessible information

Planning OrganizingPlanningPlanning Organizing

LeadingControlling

Planning Organizing

Leading

Qualities of Valuable Information

Managers are responsible for coordinating the use of resources• Resources

include people, money, materials, and information

Perform four activities

p. 13.32 Fig. 13-30

Next

How do managers use information?

objectives

strategies

tactics

money

people

management structure

communication

instructions

motivation

performance

measurement

corrective action

Access information necessary to make decisions – a trend called empowering users

Involves day-to-day activities within the company

Access information necessary to make decisions – a trend called empowering users

Applies specific programs and plans necessary to meet the stated objectives

Access information necessary to make decisions – a trend called empowering users

Involves day-to-day activities within the company

Focus on the company’s overall goals and objectives

Access information necessary to make decisions – a trend called empowering users

Involves day-to-day activities within the company

Applies specific programs and plans necessary to meet the stated objectives

Qualities of Valuable Information

What are the levels of users? The types

of information you need often depend on your employee level in the company

p. 13.32 Fig. 13-31

Next

Technology Trailblazer

Larry Ellison Oracle chairman and

co-founder Uncanny ability to motivate

his employees and partners toward a common vision

Co-founded Oracle in 1977 Goal is to grow Oracle into

the largest software company in the world

p. 13.33

Next

Click to view Web Linkthen click Larry Ellison

Types of Information Systems

What is an information system? A set of hardware, software, data, people, and

procedures that work together to produce information

p. 13.34 Fig. 13-32

Next

Procedure

An instruction, or set of instructions, a user follows to accomplish an

activity

hardwarepeople

data

procedures

software

Types of Information Systems

What are the five categories of information systems?

p. 13.34

Next

Office information systems

Transaction processing

systems

Management information

systems

Decision support systems

Expert systems

Types of Information Systems

What is an office information system (OIS)? Increases

employee productivity and assists with communications among employees

Often described as office automation

p. 13.34

Next

Types of Information Systems

What is a transaction processing system (TPS)? Captures and processes

data from day-to-day business activities

Includes several business activities• Recording a business

activity• Confirming an action

or causing a response• Maintaining data,

which involves adding new data, changing existing data, or removing unwanted data

p. 13.35 Fig. 13-33

Next

Types of Information Systems

What are forms of transaction processing systems? Initially referred

to as data processing

Intent of earliest TPSs was to process faster, reduce clerical costs, and improve customer service

p. 13.35

Next

Batch processing

The computer collects data over a period of time and processes all

transactions later, as a group

Used by first TSPs

Online transaction processing (OLTP)

The computer processes each transaction as it is entered

Most transaction processing systems today use OLTP

Types of Information Systems

What is a management information system (MIS)? Generates accurate,

timely, and organized information

Managers and other users can• Make decisions• Solve problems• Supervise activities• Track progress

Often integrated with transaction processing systems

p. 13.36

Next

Types of Information Systems

What are the three basic types of information created by an MIS? Detailed report

• Usually just lists transactions

p. 13.36 Fig. 13-34

Next

Types of Information Systems

What are the three basic types of information created by an MIS? Summary report

• Consolidates data, so you can review it quickly and easily

• Usually has totals, tables, or graphs

p. 13.36 Fig. 13-34

Next

Types of Information Systems

What are the three basic types of information created by an MIS? Exception report

• Identifies data outside of a normal condition

• Conditions, called exception criteria, define the normal activity or status range

p. 13.36 Fig. 13-34

Next

Types of Information Systems

What is a decision support system (DSS)? Helps you analyze data

and make decisions A variety of DSSs exist

• Some are company specific

• Others are available to everyone on the Web

Uses data from internal sources• From within a company

Uses data from external sources• From outside a company

p. 13.37

Next

Online analytical processing (OLAP)

Programs that analyze data and process many records at a time

MOLAP

OLAP applications that use multidimensional databases

ROLAP

OLAP applications that use relational databases

Click to view Web Linkthen click Decision Support Systems

Types of Information Systems

What is an executive information system (EIS)?

A special type of DSS

Supports the strategic information needs of executive management

Presents information as charts and tables that show trends, ratios, and statistics

p. 13.38 Fig. 13-35

Next

Types of Information Systems

What is a data warehouse? A huge database system that stores and manages the

data required to analyze historical and current transactions

The data can come from internal or external sources

p. 13.38 Fig. 13-36

Next

Click to view Web Linkthen click Data Warehouses

Web farming

The process of collecting data from the Internet as a

source for the data warehouse

Click stream

A collection of every action that users make as they move

though a Web site

Distributed database

Data exists in many separate locations throughout the network or the Internet

Data mart

Smaller version of a data warehouse

Data mining

Process of finding patterns and relationships among data

Types of Information Systems

What are terms associated with a data warehouse?

p. 13.39

Next

Types of Information Systems

What is an expert system? Captures and stores the

knowledge of human experts

Imitates human reasoning and decision making

Two main components One part of a branch of

computer science called artificial intelligence (AI)• The application of

human intelligence to computes

p. 13.40

Next

Knowledge base

The combined subject knowledge and experiences

of human experts

Inference rules

A set of logical judgments that are applied to the

knowledge base each time a user describes a situation to

the expert system

Click to view Web Linkthen click Artificial Intelligence

Step 1: Select the item you wish to purchase (cordless phone, in this case.)

Step 2: Indicate where you intend to use the phone.

Step 3: Specify the level of security you want while on the cordless phone.

Step 4: Choose your price range.Step 5: Review the list of recommendations from Ida.

Types of Information Systems

How does an expert system work?

p. 13.40 Fig. 13-37

Next

Click to view Web Linkthen click Expert Systems

Types of Information Systems

What is an integrated information system? It is often difficult to classify an information system

as belonging to only one of the five types of information systems

p. 13.41

Next Integrated information system

Office information systems

Transaction processing

systems

Management information

systems

Decision support systems

Expert systems

Summary of Databases and Information Management

Data and information The hierarchy of data Maintaining data File processing versus databases Database management systems Relational, object-oriented, and multidimensional databases Web databases Database administration Qualities of valuable information Types of information systems

Chapter 13 Complete