Download database

Chapter Eight
Database Applications and Implications
Chapter Outline
• The Electronic File Cabinet:
Database Basics
• Beyond the Basics: Database
Management Systems
• No Secrets: Computers and
Privacy
©1999 Addison Wesley Longman
8.2
The Electronic File Cabinet:
Database Basics
Like word processors,
spreadsheets, and
graphics programs,
database programs
are applications which turn programs
into productive tools.
©1999 Addison Wesley Longman
8.3
The Electronic File Cabinet:
Database Basics
Database programs are designed to
maintain collections of information
stored on computer disks.
– What Good Is a Database?
– Database Anatomy
– Database Operations
– Special-Purpose Databases
©1999 Addison Wesley Longman
8.4
What Good Is a Database?
A database is a
collection of
information stored in
an organized form in
a computer.
©1999 Addison Wesley Longman
8.5
What Good Is a Database?
Computerized databases offer several
advantages such as:
– Make it easier to store large quantities of
information.
– Make it easier retrieve information quickly
and flexibly.
– Organize and reorganize information.
– Print and distribute information in a variety
of ways.
©1999 Addison Wesley Longman
8.6
Database Anatomy
A database is a
collection of one or
more database files
records.
A file is a collection of
related information
(records).
©1999 Addison Wesley Longman
8.7
Database Anatomy
A record is the
information relating
to one person,
product, or event.
A field a discrete
chunk of information
in a record.
©1999 Addison Wesley Longman
8.8
Database Anatomy
• The view is a
display of the
information in fields
based on a
particular layout of
field data.
©1999 Addison Wesley Longman
8.9
Database Operations
Database commands
are used to retrieve,
organize, print and
distribute database
information.
– Import: receive data in
the form of text files.
– Browse: navigate
through information by
just looking at it.
©1999 Addison Wesley Longman
8.10
Database Operations
– Query: search or
select one or more
specific records.
– Sort: rearrange
records
(alphabetically or
numerically).
– Report: printout of
an ordered list of
records.
©1999 Addison Wesley Longman
8.11
Special-Purpose Database
Programs
Specialized database
software is
preprogrammed
for specific data
storage and
retrieval purposes.
©1999 Addison Wesley Longman
8.12
Special-Purpose Database
Programs
Geographical
information
systems (GISs):
include geographic
and demographic
data in map form.
©1999 Addison Wesley Longman
8.13
Special-Purpose Database
Programs
• Personal
information
managers (PIMs):
an electronic
organizer that is
customized to fit
individual needs.
©1999 Addison Wesley Longman
8.14
Beyond the Basics:
Database Management Systems
A file manager is a
program that allows
users to work with
one file at a time.
©1999 Addison Wesley Longman
8.15
Beyond the Basics:
Database Management Systems
Database Management Systems (DBMSs)
– is a program or system of programs that
can manipulate data in a large collection of
files
– different users see different points of view
– may be interactive
©1999 Addison Wesley Longman
8.16
Database
©1999 Addison Wesley Longman
8.17
Database Management
System
©1999 Addison Wesley Longman
8.18
data base management
system
• a three level framework
– internal level
• store the elemental pieces of data
– conceptual level
• fields and records
– external level
• a user dependent view
©1999 Addison Wesley Longman
8.19
data base management
system(II)
• DBMS is a set of programs used to
– define and establish the database
– interface with the user
– process the transactions
– control the contents
– perform administrative functions
©1999 Addison Wesley Longman
8.20
data independency
• user interface are immune to the
change in storage and data access
methods
©1999 Addison Wesley Longman
8.21
options for the data models
• hierarchical model
• network model
• relational model
©1999 Addison Wesley Longman
8.22
hierarchical model
• tree structure
• efficient for particular queries
• lack of flexibility
©1999 Addison Wesley Longman
8.23
Hierarchical Model
©1999 Addison Wesley Longman
8.24
network model
• emphasize on the links between records
• flexible
• complex
©1999 Addison Wesley Longman
8.25
Network Model
©1999 Addison Wesley Longman
8.26
relational model
• each item is treated as an entry in the
relation table
• simple and easy
©1999 Addison Wesley Longman
8.27
What Makes a Database
Relational?
• Relational
model - a
mathematical
model that
combines
data in tables.
©1999 Addison Wesley Longman
8.28
centralized systems
• all records and files and all user
interfaces are controlled by one group
• advantages
– consistency
– data independent
– easy to retrieve
©1999 Addison Wesley Longman
8.29
distributed systems
• highly responsive to differences in data
gathering, storage and access
©1999 Addison Wesley Longman
8.30
security and privacy
• security---protecting against
unauthorized disclosure, modification or
destruction
• privacy--- individual’s right to share or
not to share information with others
©1999 Addison Wesley Longman
8.31
Attack and defense
• attack strategies
– Trojan Horses, viruses, ...
• defense strategies
– firewalls, making backups, encipher the
data, ...
• highly sensitive data should not be
stored in resource sharing systems
©1999 Addison Wesley Longman
8.32
access control and constraints
• access to database---password
• access to specific data---second
password
• deny access to specific data
• update process allowed only by a
designated person from a specific
terminal during certain time
• using medium such as magnetic card
©1999 Addison Wesley Longman
8.33
logging
• log records contain
–
–
–
–
–
–
each access or update request
user’s name
terminal
time
sensitive of information sought
granted or not
• analysis and surveillance programs may be
used to protect the database.
©1999 Addison Wesley Longman
8.34
No Secrets:
Computers and Privacy
Big Brother and Big Business
Telemarketers
©1999 Addison Wesley Longman
8.35
The Privacy Problem
More than 15,000 specialized marketing
databases contain 2 billion names.
These databases contain characteristics
like age, income, religion, and even
personal preference.
©1999 Addison Wesley Longman
8.36
Big Brother and Big Business
• Government uses
record matching to
locate criminals
ranging from tax
evaders to mass
murderers.
• Credit bureaus collect
information about us
and allows us to use
credit cards.
©1999 Addison Wesley Longman
8.37
Big Brother and Big Business
• With the increased amount of
information available, problems that
arise include:
– Data errors are common
– Data can become nearly immortal
– Data isn’t secure
©1999 Addison Wesley Longman
8.38
Privacy
• the US government has no right to put
together all the personal information in
the computerized data bank.
• The Privacy Act---(Dec. 31, 1974)
– the individuals have the right to access and
if necessary change or update information
about themselves in all but a very few
federal data banks
©1999 Addison Wesley Longman
8.39