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Modern Database Management 6thEdit ionJeffrey A . Ho ffer, Mary B . Presco tt, Fred R.
McFadden
Ins truc tor : Mr. Sadiq ShahDate: 10/09/12
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Chapter 1:The Database Environment
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Chapter 1
Tentative Grading Policy
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20% Mid Tem Exam
70% Final Exam
5% Project/Assignments/Presentation
5% Quizzes
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Chapter 1
Class Etiquettes
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Respect each others
Keep your mobiles switched off
Be careful of class timing
Late comer may be not allowed
Delay talks with colleagues
Avoid interruption in class
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Chapter 1
Definitions
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Data: facts, text, graphics, images, sound,
video segments that have some meaning.
Database: An organized collection of logicallyrelated data
Information: Data processed to be useful in
decision making
Metadata: Data that describes data
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Chapter 1
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Figure 1-1a Data in Context
Large volume of facts, difficultto interpret or make decisions
based on
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Chapter 1
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Figure 1-1b Summarized data
Useful information that managers can use for
decision making and interpretation
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Chapter 17
Table 1-1 Metadata
Descriptions of the properties or characteristics of the
data, including data types, field sizes, allowablevalues, and documentation
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Chapter 1
Disadvantages of File Processing
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Program-Data DependenceAll programs maintain metadata for each file they use
Data Redundancy (Duplication of data)
Different systems/programs have separate copies of the same
data Limited Data Sharing
No centralized control of data
Lengthy Development Times
Programmers must design their own file formats
Excessive Program Maintenance
80% of of information systems budget
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Chapter 19
Figure 1-2 Three file processing systems at Pine
Valley FurnitureDuplicate
Data
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Chapter 1
Problems with Data Dependency
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Each application programmer must maintaintheir own data
Each application program needs to includecode for the metadata of each file
Lack of coordination and central control
Non-standard file formats
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Chapter 1
Problems with Data Duplication
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Waste of space to have duplicate data
Causes more maintenance headachesThe biggest Problem:
When data changes in one file, could
cause inconsistenciesCompromisesdata integri ty
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Chapter 1
SOLUTION:
The DATABASE Approach
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Central repository of shared data
Data is managed by a controlling
agent
Stored in a standardized,
convenient formRequires a Database Management System (DBMS)
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Chapter 1
Database Management System
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A DBMS is a data storage and retrieval system
which permits data to be stored non-redundantlywhile making it appear to the user as if the data is
well-integrated.
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Chapter 1
Database Management System
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DBMS manages dataresources like an operating
system manages hardware
resources
DBMS Databasecontainingcentralizedshared data
Application#1
Application
#2
Application#3
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Chapter 1
Advantages of Database Approach
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Program-Data Independence Metadata stored in DBMS, so applications dont need to
worry about data formats
Results in: increased application development and
maintenance productivityMinimal Data Duplication
Leads to increased data integrity/consistency
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Chapter 1
Advantages of Database Approach
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Improved Data Sharing Different users get different views of the data
Enforcement of StandardsAll data access is done in the same way
Better Data Accessibility/ Responsiveness Use of standard data query language (SQL)
Security, Backup/Recovery, Concurrency Disaster recovery is easier
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Chapter 1
Costs and Risks of the
Database Approach
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Up-front costs: Installation Management Cost and Complexity
Conversion Costs
Ongoing Costs Requires New, Specialized Personnel
Need for Explicit Backup and Recovery
Organizational Conflict Old habits die hard
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Chapter 118
Figure 1-5
Client/server
system forPine Valley
Furniture
Company
Fi 1 6 C t i i (Pi V ll F it C )
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Chapter 119
Figure 1-6 Customer invoice (Pine Valley Furniture Company)
Application program functions:
inserting new data, updatingexisting data,
deleting existing data, reading data for display
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Chapter 1
The Range of
Database Applications
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Personal Database standalone desktopdatabase
Workgroup Database local area network (
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Chapter 121
Figure 1-7
Typical data
from apersonal
computer
database
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Figure 1-8 Workgroup database with local area network
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Figure 1-9 An
enterprise
datawarehouse
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Chapter 1
Components of the
Database Environment
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CASE Tools computer-aided software engineering
Repository centralized storehouse of metadata
Database Management System (DBMS) software formanaging the database
Database storehouse of the data
Application Programs software using the data
User Interface text and graphical displays to users
Data Administrators personnel responsible for maintainingthe database
System Developers personnel responsible for designingdatabases and software
End Users people who use the applications and databases
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Chapter 125
Figure 1-10
Componentsof the
database
environment
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Chapter 126
End of lecture 1