MANAGING DATA RESOURCES
c h a p t e r
7
MANAGING
DATA
RESOURCES
7.1
© 2002 by Prentice Hall
LEARNING OBJECTIVES
• COMPARE TRADITIONAL FILE
ORGANIZATION & MANAGEMENT
TECHNIQUES
• DESCRIBE HOW DATABASE
MANAGEMENT SYSTEM
ORGANIZES
INFORMATION
*
7.2
© 2002 by Prentice Hall
LEARNING OBJECTIVES
• IDENTIFY TYPES OF DATABASE,
PRINCIPLES OF DATABASE DESIGN
• DISCUSS DATABASE TRENDS
*
7.3
© 2002 by Prentice Hall
MANAGEMENT CHALLENGES
• TRADITIONAL DATA FILE
ENVIRONMENT
• DATABASE APPROACH TO DATA
MANAGEMENT
• CREATING DATABASE
ENVIRONMENT
• DATABASE TRENDS
*
7.4
© 2002 by Prentice Hall
MANAGEMENT CHALLENGES
1. ORGANIZATIONAL OBSTACLES:
Challenges existing power structure, requires organizational restructure
2. COST / BENEFIT CONSIDERATIONS:
Large initial costs, delayed benefits, tangible, intangible
*
7.5
© 2002 by Prentice Hall
FILE ORGANIZATION
• BIT: Binary Digit (0,1; Y,N; On,Off)
• BYTE: Combination of BITS which represent a CHARACTER
• FIELD: Collection of BYTES which represent a DATUM or Fact
• RECORD: Collection of FIELDS which reflect a TRANSACTION
*
7.6
© 2002 by Prentice Hall
FILE ORGANIZATION
• FILE: A Collection of similar
RECORDS
• DATABASE: An Organization’s
Electronic Library of FILES organized to serve business applications *
7.7
© 2002 by Prentice Hall
FILE ORGANIZATION
• ENTITY: Person, place, thing, event about which data must be kept
• ATTRIBUTE: Description of a particular ENTITY
• KEY FIELD: Field used to retrieve, update, sort RECORD
*
7.8
© 2002 by Prentice Hall
KEY FIELD
Field in Each Record
Uniquely Identifies THIS Record
For RETRIEVAL
UPDATING
SORTING
*
7.9
© 2002 by Prentice Hall
PROBLEMS WITH TRADITIONAL FILE
ENVIRONMENT
•
•
•
•
•
7.10
DATA REDUNDANCY
PROGRAM / DATA DEPENDENCY
LACK OF FLEXIBILITY
POOR SECURITY
Flat
File
LACK OF DATA
SHARING &
AVAILABILITY
*
© 2002 by Prentice Hall
SEQUENTIAL VS. DIRECT
FILE ORGANIZATION
• SEQUENTIAL: Tape oriented; one file follows another; follows physical sequence • DIRECT: Disk oriented; can be
7
MANAGING
DATA
RESOURCES
7.1
© 2002 by Prentice Hall
LEARNING OBJECTIVES
• COMPARE TRADITIONAL FILE
ORGANIZATION & MANAGEMENT
TECHNIQUES
• DESCRIBE HOW DATABASE
MANAGEMENT SYSTEM
ORGANIZES
INFORMATION
*
7.2
© 2002 by Prentice Hall
LEARNING OBJECTIVES
• IDENTIFY TYPES OF DATABASE,
PRINCIPLES OF DATABASE DESIGN
• DISCUSS DATABASE TRENDS
*
7.3
© 2002 by Prentice Hall
MANAGEMENT CHALLENGES
• TRADITIONAL DATA FILE
ENVIRONMENT
• DATABASE APPROACH TO DATA
MANAGEMENT
• CREATING DATABASE
ENVIRONMENT
• DATABASE TRENDS
*
7.4
© 2002 by Prentice Hall
MANAGEMENT CHALLENGES
1. ORGANIZATIONAL OBSTACLES:
Challenges existing power structure, requires organizational restructure
2. COST / BENEFIT CONSIDERATIONS:
Large initial costs, delayed benefits, tangible, intangible
*
7.5
© 2002 by Prentice Hall
FILE ORGANIZATION
• BIT: Binary Digit (0,1; Y,N; On,Off)
• BYTE: Combination of BITS which represent a CHARACTER
• FIELD: Collection of BYTES which represent a DATUM or Fact
• RECORD: Collection of FIELDS which reflect a TRANSACTION
*
7.6
© 2002 by Prentice Hall
FILE ORGANIZATION
• FILE: A Collection of similar
RECORDS
• DATABASE: An Organization’s
Electronic Library of FILES organized to serve business applications *
7.7
© 2002 by Prentice Hall
FILE ORGANIZATION
• ENTITY: Person, place, thing, event about which data must be kept
• ATTRIBUTE: Description of a particular ENTITY
• KEY FIELD: Field used to retrieve, update, sort RECORD
*
7.8
© 2002 by Prentice Hall
KEY FIELD
Field in Each Record
Uniquely Identifies THIS Record
For RETRIEVAL
UPDATING
SORTING
*
7.9
© 2002 by Prentice Hall
PROBLEMS WITH TRADITIONAL FILE
ENVIRONMENT
•
•
•
•
•
7.10
DATA REDUNDANCY
PROGRAM / DATA DEPENDENCY
LACK OF FLEXIBILITY
POOR SECURITY
Flat
File
LACK OF DATA
SHARING &
AVAILABILITY
*
© 2002 by Prentice Hall
SEQUENTIAL VS. DIRECT
FILE ORGANIZATION
• SEQUENTIAL: Tape oriented; one file follows another; follows physical sequence • DIRECT: Disk oriented; can be