Transcript Chap13 Presentation

Chapter 13
Databases and
Information
Management
Chapter 13 Objectives
Next
p. 13.2
Explain why data and
information are important to an
organization
Explain how to use a
query language
Identify file maintenance
techniques
Understand how Web
databases work
Differentiate between the file
processing and database
approaches
Discuss the responsibilities of
the database analysts and
administrators
Discuss the advantages of
using a database management
system (DBMS)
Identify the qualities of
valuable information
Describe characteristics of
relational and object-oriented
databases
Describe the various types of
information systems
Understand the concept of a
data warehouse
Data and Information
How are data and information related?


Computers
process data
into
information
Data is raw
facts;
information is
data that is
organized and
meaningful
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p. 13.2 Fig. 13-1
data
information
Data and Information
What is a database?

Collection of data
organized so you can
access, retrieve, and use it
 Database software allows
you to
• Create database
• Add, change, and delete data
• Sort and query database
 Database software also is called
database management system
(DBMS)
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p. 13.2
Data and Information
What is data integrity?

Degree to which
data is correct
 When database
contains errors, it
loses integrity
Garbage in,
garbage out
(GIGO)
Cannot create correct
information from
incorrect data
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p. 13.3
The Hierarchy of Data
What is a field?

Combination of one or more characters
 Smallest unit of data user accesses
 Field name uniquely identifies each field
fields
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p. 13.4 Fig. 13-3
The Hierarchy of Data
What are characteristics of a field?

Data type
 Field size
Text – letters, numbers, or special characters
Numeric – numbers only
Currency – dollar and cent amounts or
numbers containing decimal values
Date – month, day, year, and sometimes
time information
data types
Memo – lengthy text entries
Yes/No – only the values Yes or No
Hyperlink – Web address that links to a
document or a Web page
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p. 13.5
Object – picture, audio, video, or a document
created in other applications such as word
processing or spreadsheet
The Hierarchy of Data
What is a record?

Group of related fields
field
names
records
key field
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p. 13.5 Fig. 13-2
Uniquely identifies
each record in file
Also called primary
key
maximum
characters
in Rating
field
The Hierarchy of Data
What is a data file?

Collection of related records stored on disk
 Each record in file contains same fields
 Each field contains different data
 Also called a file
 Database usually composed of group of related data files
fields
Sample Customer File
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p. 13.5 Fig. 13-3
records
Maintaining Data
What is file maintenance?

Procedure that
keeps data
current
Adding records
Changing records
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p. 13.6
Deleting records
Maintaining Data
What is validation?

Validity check analyzes entered data to help
ensure it is correct
Click to view
Web Link
then click
Validity Checks
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p. 13.9 Fig. 13-7
Maintaining Data
What is a completeness check?

Error message
displays stating
which required
fields are blank
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p. 13.10 Fig. 13-8
required
information
Maintaining Data
What is a check digit?

Number(s) or
character(s)
appended to or
inserted into
primary key value
 Used to confirm
accuracy of
primary key value
Initial primary key:
1367
Calculate total of digits:
1 + 3 + 6 + 7 = 17
Calculate total of digits again:
1+7=8
Check digit = 8
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p. 13.10
Resulting primary key: 13678
File Processing Versus
Databases
What is a file processing system?


Each department or area within organization has own set
of files
Records in
one file often
do not relate
to records in
any other file
Problem: same
customer may have
different name or
address in each file
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p. 13.11 Fig. 13-9
File Processing Versus
Databases
What is the database approach?


Many programs
and users can
share data in
database
Secures data so
only authorized
users can
access certain
data items
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p. 13.12 Fig. 13-10
only one customer
file in company
database
File Processing Versus
Databases
What are the strengths of the database approach?
Reduced data redundancy
Improved data integrity
Shared data
Reduced development time
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p. 13.13
Easier reporting
File Processing Versus
Databases
How do a database application and a file
processing application differ in the way they
might store data?
File processing
example
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p. 13.13 Fig. 13-11
Database
example
Database
Management Systems
What is a database management system (DBMS)?

Software that allows you to create, access, and
manage a database
Click to
view
animation
Click to view
Web Link
then click
Database
Managemen
t Systems
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p. 13.14 Fig. 13-12
Database
Management Systems
What is a data dictionary?

Contains
data about
each file in
database
and each
field within
those files
Click to
view Web
Link
then click
Data
Dictionary
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p. 13.15 Fig. 13-13
Database
Management Systems
What is a query language?

Simple,
English-like
statements
that allow
you to
specify data
to display,
print, or
store
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p. 13.16 Fig. 13-14
query
results
Database
Management Systems
What is a query by example (QBE)?

Program
retrieves
records that
match criteria
entered in
form fields
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p. 13.17 Fig. 13-15
query by example screen
query results
Database
Management Systems
What is a form?

Window on screen that provides areas for
entering or changing data in database
 E-form is similar, but used on Web
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p. 13. Fig. 13-16
Database
Management Systems
What is a report generator?

Generates report
without user’s
knowledge of
programming
 Comes with a
database
report
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p. 13. 19Fig. 13-18
Database
Management Systems
What is data security?

DBMS
provides means
to ensure
only authorized
users can access
data with
specified
privileges
Click to
view video
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p. 13.19
Access privileges
Define activities that specific
user or group of users can
perform
Read-only privileges
User can retrieve data,
but cannot change it
Full-update privileges
User can retrieve and
change the data
Database
Management Systems
What is a log?


Listing of activities that change database contents
For every change, DBMS places three items in log file
before image: a copy of the customer record prior to the change
the actual change of data
after image: a copy of the customer record after the change
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p. 13.20
Fig. 13-18
Database
Management Systems
What is a recovery utility?

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p. 13.20
Uses log file
and/or
backups to
restore
database
when it is
damaged or
destroyed
Rollforward
DBMS uses log to
re-enter changes made to
database since last save
or backup
Rollback
Also called forward
recovery
DBMS uses log to undo
any changes made to
database during a
certain period of time
Also called backward
recovery
Relational, Object-Oriented
and Multidimensional
What is a data model? Databases

Every database
and DBMS
based on
specific data
model
 Composed of
rules and
standards
Click to
view
animation
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p. 13.21 Fig. 13-20
Relational
Databases
Object-oriented
Databases
Object-relational
Databases
Multidimensional
Databases
Relational, Object-Oriented,
and Multidimensional
Databases
What is a relational database?

Stores data in tables that consist of rows and
columns
• Each row has primary key
• Each column has a unique name
Relational terminology
Click to view
Web Link
then click
Relational
Databases
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p. 13.22 Fig. 13-21
Relational, Object-Oriented,
and Multidimensional
Databases
What is normalization?

Process
designed to
ensure data
within
relations
(tables)
contains
least
amount of
duplication
row
column
table
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p. 13.22 Fig. 13-22
relationships
Relational, Object-Oriented,
and Multidimensional
Databases
What is relational algebra?

Uses variables
and operations
to build new
relations
 Used to
manipulate and
retrieve data
Projection operation
Retrieves data from
columns (fields)
Selection operation
Retrieves data from
certain rows (records)
Join operation
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p. 13.24
Combines data from two or
more tables
Relational, Object-Oriented,
and Multidimensional
Databases
What is an example of a projection
operation?

Extracts data from column (field)
all rows and columns in Movie table
projection operation results
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p. 13.24 Fig. 13-23
Relational, Object-Oriented,
and Multidimensional
Databases
What is an example of a selection
operation?

Extracts data from a row (record)
all rows and columns in Movie table
selection operation results
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p. 13.24 Fig. 13-23
Relational, Object-Oriented,
and Multidimensional
Databases
What is an example of a combined
projection and selection operation?

Extracts data from column (field) for certain rows (records)
all rows and columns in Movie table
projection and selection
operation results
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p. 13.24 Fig. 13-23
Relational, Object-Oriented,
and Multidimensional
Databases
What is an example of a join operation?

Combines data from two or more tables using a
common column
Movie Table
Rental Table
Rental Table and Movie Table joined
on Movie ID Column
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p. 13.24 Fig. 13-24
Relational, Object-Oriented,
and Multidimensional
Databases
What is Structured Query Language (SQL)?



Allows you to manage, update, and retrieve data
Uses relational algebra
Has special keywords and rules included in SQL
statements
projection operation
Click to
view Web
Link
then click
SQL
join operation
selection operation
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p. 13.25 Fig. 13-25
Relational, Object-Oriented,
and Multidimensional
Databases
What is an object-oriented database
(OODB)?

Stores data in
objects
 Advantages
• Can store more
types of data
• Can access data
faster
Click to view Web Link
then click Object-Oriented
Databases
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p. 13.26
Object
Item that can contain both data
and activities that read or
process data
Object query language (OQL)
Manipulates and retrieves objectoriented and object-relational data
Relational, Object-Oriented,
and Multidimensional
Databases
What are examples of applications appropriate for
an object-oriented database?
Multimedia databases
Hypertext databases
Store images, audio clips,
and/or video clips
Contain text links to other
documents
Groupware databases
Hypermedia databases
Store documents such as
schedules, calendars, manuals,
memos, and reports
Contain text, graphics,
video, and sound
Computer-aided design
(CAD) databases
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p. 13.26
Store data about engineering,
architectural, and scientific
designs
Web databases
Link to e-form on Web page
Relational, Object-Oriented,
and Multidimensional
Databases
What is a multidimensional database
(MDDB)?

Click to view
Web Link
then click
Multidimensional
Databases
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p. 13.27
Stores data in
dimensions
Advantage
Can consolidate
data much
faster than
relational
database
Database
Administration
What is the role of the database analyst and
administrator?
Database analyst (DA)
Focuses on meaning and usage of data
Decides proper placement of fields,
defines relationships among data, and
identifies users’ access privileges
Click to view
Web Link
then click
Database
Administrator
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p. 13.30
Database administrator
(DBA)
Creates and maintains data dictionary,
manages database security, monitors
database performance, and checks
backup and recovery procedures
Database
Administration
What is the role of the employee as a user?


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p. 13.30
Employee should learn how to utilize data in database
Take part in designing
database that will
help achieve
company’s overall
goals
Database
Administration
What are
guidelines
for
developing a
database?
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p. 13.30 Fig. 13-29
Qualities of Valuable
Information
What are the qualities of valuable
information?
Accurate
Organized
Accessible
Verifiable
Useful
Timely
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p. 13.30
Cost-effective
Qualities of Valuable
Information
How do managers
use information?
1. objectives;
strategies;
tactics
2. money; people;
management; structure
3. communication;
instructions;
motivation
4. performance;
measurement;
corrective action
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p. 13.32 Fig. 13-30
Planning
Controlling
Organizing
Leading
Qualities of Valuable
Information
What are the levels of users?
Focus on the
company’s overall
goals and objectives
Applies specific programs
and plans necessary to
meet the stated objectives
Involves day-to-day
activities within the
company
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p. 13.32 Fig. 13-31
Access information
necessary to make
decisions – a trend called
empowering users
Types of Information
Systems
What is an information system?

Set of hardware, software, data, people, and procedures
that work together to produce information
hardware
people
procedures
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p. 13.34 Fig. 13-32
software
data
Types of Information
Systems
What are the five categories of information
systems?
Decision
support
systems
Office information
systems
Management
information
systems
Transaction
processing
systems
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p. 13.34
Expert
systems
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
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p. 13.36
Types of Information
Systems
What is a detailed report?

Lists one record per line
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p. 13.36 Fig. 13-34
Types of Information
Systems
What is a summary report?

Consolidates
data, so you
can review it
quickly and
easily
 Usually has
totals, tables,
or graphs
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p. 13.36 Fig. 13-34
Types of Information
Systems
What is an exception report?

Identifies data outside of normal condition
 Conditions, called exception criteria, define
normal activity or status range
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p. 13.36 Fig. 13-34
Types of Information
Systems
What is a decision support system (DSS)?

Helps
managers
analyze data
and make
decisions
 One type of
DSS is
Click to
view Web
executive
Link
information
then click
Decision
Support
system (EIS)
Systems
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p. 13.37 Fig. 13-35
Types of Information
Systems
What is a data warehouse?

Huge database system that stores and manages data
required to analyze historical and current transactions
Click to view Web Link
then click Data Warehouses
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p. 13.38 Fig. 13-36
Types of Information
Systems
What are terms associated with a data
warehouse?
Distributed database
Web farming
Process of collecting data
from Internet as source for
data warehouse
Data exists in many separate
locations throughout
network or Internet
Data mart
Click stream
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p. 13.39
Collection of every action that
users make as they move
through Web site
Smaller version of data
warehouse
Data mining
Process of finding patterns and
relationships among data
Types of Information
Systems
What is an expert system?

Captures and
stores knowledge
of human experts
Knowledge base
Combined subject
knowledge and experiences
of human experts
Inference rules
Click to view
Web Link
then click
Artificial
Intelligence
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p. 13.40
Set of logical judgments
applied to knowledge base
each time user describes
situation to expert system
Types of Information
Systems
What is an integrated information system?

Five information systems combined in some way
Decision
support
systems
Office information
systems
Transaction
processing
systems
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p. 13.41
Management
information
systems
Expert
systems
Integrated
information system
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
 Database administration
 Qualities of valuable information
 Types of information systems
Chapter 13 Complete