Transcript Chapter 7 - SISF WEB SITE Starting Page

Computer
Confluence 7/e
© 2006 Prentice-Hall, Inc.
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Computer Confluence 7/e
Chapter 7
Database Applications and Implications
© 2006 Prentice-Hall, Inc.
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Chapter 7
Objectives
 Explain what a database is and describe its basic structure
 Identify the kinds of problems that can be best solved with
database software
 Describe different kinds of database software, from simple file
managers to complex relational databases
© 2006 Prentice-Hall, Inc.
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Objectives (continued)
 Describe database operations for storing, sorting, updating,
querying, and summarizing information
 Give examples of ways in which large, easily accessible
databases make lives safer or more convenient
 Explain the ways databases threaten our privacy
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Bill Gates Rides the Digital Wave
 Bill Gates and Paul Allen formed a company called Microsoft to
produce and market Microsoft Basic, a version of the Basic
programming language for microcomputers

Basic quickly became the standard language installed in virtually
every computer
 Microsoft’s biggest break came when IBM went shopping for an
operating system for its PC
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Bill Gates Rides the Digital Wave
 Today Bill Gates and Microsoft dominate
the PC software industry, selling operating
systems, applications programs, server
software, and software development tools:
 Internet Explorer Web browser is a central component of
the Windows OS
 Microsoft desktop applications have links to the Internet
 Microsoft has partnerships with dozens of Web-related
businesses worldwide
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The Electronic File Cabinet: Database Basics
What Good Is a Database?
 A database:
 A collection of information
stored on computer disks
 Database software:
 Application software
(like word processing and
spreadsheet software)
 Designed to maintain databases
(collections of information)
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 Advantages offered by computerized databases:
 Make it easier to store large quantities of information
 Make it easier to retrieve information quickly and flexibly
 Make it easy to organize and reorganize information
 Make it easy to print and distribute information in a variety of ways
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Database Anatomy
Database program: a software tool for organizing the
storage and retrieval of information
Database: a collection of information stored in an
organized form in a computer
Typically composed of one or more tables
A collection of related information
A collection of records
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 A record is the information relating to one person, product, or
event
 Each discrete piece of information in a record is a field
Field
Record
Table
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 The type of information a field can hold is determined by its:
 Field type or
 Data type
 Database programs provide you with more than one way to
view data:
 Form views
 Show one record at a time
 List views
 Display several records in lists similar to the way a spreadsheet displays
data
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In any view, fields can be
rearranged without changing
the underlying data
Form View
List View
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Database Operations
 Import: receives data in the form of text files
 Browse: navigates through information
 Query: finds records that match specific criteria
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 Sort: rearranges records (alphabetically or numerically)
 Printing reports, labels, and form letters: a report is an
ordered list of selected records and fields in an easy-to-read
format
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 Most modern database management programs support a standard
language for programming complex queries called SQL
(Structured Query Language)



Available for many database management systems
Programmers and sophisticated users don’t need to learn new languages
when they work with new systems
Graphical user interfaces allow point-and-click queries

Insulates users from the complexities of the query language
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Screen Test: Querying a Web Search Database
To search for articles
online about a new method
for recycling laser printer
toner cartridges, you can
visit a search engine such
as Google
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When you hit the
“Search” button, the
search engine will return
a list of links, sorted by
relevancy
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Selecting any of the
links will cause the
corresponding page to
load
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Special-Purpose Database Programs
 Specialized database software: preprogrammed for specific data
storage and retrieval purposes
 Geographical information systems (GIS): include geographic
and demographic data in map form
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Personal information manager (PIM): an
electronic organizer
Automates some or all of the following functions:
Address/phone book
Appointment calendar
To-do list
Miscellaneous notes
Handheld computers can share information with
applications such as iCalendar running on PCs and
Macintoshes
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Beyond the Basics: Database Management
Systems
From File Managers to Database Management Systems
 File manager: enables users to work with one file at a time
 Database management system (DBMS): manipulates data in a
large collection of files, cross-referencing between files as
needed
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 A DBMS can be used interactively, or it can be controlled
directly by other programs
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What Makes a Database Relational?
To most users, a relational database program is one
that allows tables to be related to each other
 Changes in one table are reflected in other tables
automatically
To computer scientists, the term relational database
has a technical definition related to:
 The underlying structure of the data
 The rules specifying how that data can be manipulated
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 The structure of a relational database is based on the relational
model―a mathematical model that combines data in tables
A database is relational
when files are related
to each
other, such as this
Student ID field in the
Student file
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Beyond the Basics: Database Management
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The Many Faces of Databases
 Large databases often contain hundreds of interrelated tables
 A database management system can shield users from the
complex inner workings of the system, providing them with only
the information and commands they need to get their jobs done
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The Many Faces of Databases
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Database Trends
 Batch processing: users accumulate transactions and input
them into the computer in large batches
 Real-Time computing: allows instant access to information
 Interactive processing: has replaced batch processing for
most applications
 Users can now interact with data through terminals, viewing and
changing values online in real-time
 Batch processing is still used for jobs in which it makes sense to do a lot
of transactions at once
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Client/server computing
involves two-way
communications between
applications running on the
"client" PC and the "server"
PC
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Downsizing and Decentralizing: Using a client/server
approach
 Today many businesses use a client/server approach using database servers
 Enables users to take advantage of the PC’s simple user interface and
convenience, while still having access to data stored on large server systems
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 Data Mining:
 The discovery and extraction of hidden predictive information from large
databases
 Uses statistical methods and artificial intelligence technology

Locates trends and patterns in data that would have been overlooked by
normal database queries
“The goal is
information
at your
fingertips.”
Bill Gates
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 Databases and the Web
 Information is available via a company’s Intranet and the Internet
 HTML, the language used to construct most Web pages, wasn’t designed
to build database queries
 XML, a newer, more powerful data description language, is designed
with industrial-strength database access in mind
 Web database strategies revolve around directories
 Directories are at the heart of many customer relationship management
(CRM) systems—software systems for organizing and tracking
information on customers
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Rules of Thumb: Dealing with Databases




Choose the right tool for the job
Think about how you’ll get the information out before you put it in
Start with a plan, and be prepared to change your plan
Make your data consistent; inconsistencies can mess up sorting and
make searching difficult
 Databases are only as good as their data
 Query with care
 If at first you don’t succeed, try another approach
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Object-Oriented Databases
Make database construction and usage more flexible
Store software objects that contain procedures (or
instructions) along with data
Often used in conjunction with object-oriented
programming languages
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Object-Oriented Databases: An Example
 A database of images, containing a class for photos
 There is one instance of this class – one object for every
photograph in the database
 Data associated with this object: photographers name,
description of photo, copyright status, and the image itself
 One operation for the class is producing a thumbnail
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Object-Oriented
 Easy manipulation of
various types of data
 Saves time by reusing
objects
 Associates actions with
the data
© 2006 Prentice-Hall, Inc.
Relational
 Not good with
unstructured data (audio,
video clips)
 Will still be used in
combination with object
oriented databases - as
hybrids
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 Multimedia Databases
 Serve as indexes for art, photographs, maps, video clips, and other media
files
 Natural Language Databases
 Allow users to ask for data using the same language used to address
humans (natural language queries)
 Future databases will undoubtedly incorporate more artificial intelligence
technology
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www.freeanswers.com enables
users to ask questions about
computers by stating their
queries in plain English and
other natural languages
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No Secrets: Computers and Privacy
Personal Data: All About You
 More than 15,000 specialized
marketing databases contain
2,000,000,000 names
 These databases contain
characteristics like age, income,
religion
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No Secrets: Computers and Privacy
What is privacy?
 A common theme in privacy is the notion of access


Physical proximity to the person
Knowledge about that person
 People need a certain amount of privacy to maintain their
dignity and freedom

How much dignity would you have if everyone could read your
mind?
 Information about people can be of great value to society

Many parents would like to know identities of convicted sex
offenders
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No Secrets: Computers and Privacy
The Privacy Problem
 Protection against invasion of privacy is not explicitly
guaranteed by the U.S. Constitution


The right to privacy implied by other constitutional guarantees
Debates rage about what this means
 Federal and state laws provide forms of privacy protection

Most of those laws were written years ago
 Most European countries have had strong privacy protection
laws for years
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No Secrets: Computers and Privacy
Big Brother and Big Business
 Other information technologies amplify the threat to personal
privacy, too:
 Networks: make it possible for personal data to be transmitted almost
anywhere instantly
 Microsoft’s Passport, part of its .NET technologies, can optionally
collect in a central database controlled by Microsoft
 Passwords
 Credit card numbers
 Other consumer information
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No Secrets: Computers and Privacy
 Workplace monitoring technology: enables managers to
learn more than ever before about the work habits and
patterns of workers
 Surveillance cameras: increasingly used for nabbing
routine traffic violations and detecting security violators,
can be combined with picture databases to locate
criminals—and others
 Surveillance satellites: can provide permanent peepholes
into our lives for anyone willing to pay the price
 Cell phones: are now required by law to include
technology to determine and transmit their locations to
emergency personnel responding to 911 calls
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No Secrets: Computers and Privacy
Rules of Thumb: Your Private Rights
 Your Social Security number is yours
—don’t give it away
 Say “no” to direct mail and phone
solicitations, sharing of personal
information, and pollsters
 Know your electronic rights
 Support organizations that fight for privacy rights
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Lesson Summary
 Database programs enable users to quickly and efficiently
store, organize, retrieve, communicate, and manage large
amounts of information
 Database programs enable users to view data in a variety of
ways, sort records in any order, and print reports, mailing
labels, and other custom printouts
 Database management systems (DBMSs) can work with
several data sources at once, cross-referencing information
among files when appropriate
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Lesson Summary (continued)
 The trend today is clearly away from large, centralized
databases accessible only to data processing staff
 Organizations are moving toward a client/server approach that
enables users to have access to data stored in servers throughout
the organization’s network
 The accumulation of data by government agencies and
businesses is a growing threat to our right to privacy
 While there are many legitimate uses for these procedures, there
is also a great potential for abuse
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