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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
Next
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
Next
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
Next
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
Next
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
Next
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