11
Databases
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Objectives
• How data organized
• Types of file organization
• Advantages of database
• Essential parts of DBMS
• Ways of organizing DBMS
• Uses and issues
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2002
Data Organization
• Smallest to largest
• Key fields
• Helps with processing
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2002
Key Field
• Unique identifier
• Common examples
– Social security number
– Driver’s license
– Credit card account
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2002
Processing
• Batch processing -- later
• Real-time processing -- now
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2002
Master vs. Transaction
• Master – contains all records
– Current to last update
• Transaction – recent changes to
records
– Accumulation file
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2002
File Organization
• Sequential file
organization
• Direct file organization
• Index sequential file
organization
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2002
Database
• Sharing – one department to another
• Security – passwords to access
• Data redundancy
• Data integrity
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2002
DBMS
• Database Management System
– Access
– Oracle
• Data dictionary
– Structure description
– Defines field characteristics
• Query language
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2002
Organization
• Hierarchical
• Network
• Relational
• Object-oriented
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2002
Hierarchical Database
• Nodes
• Branches
• Subordinate (child)
• One parent per node
• Subordinate is node to parent
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2002
Network Database
• Hierarchical node arrangement
• Many-to-many relationship
• Access via multiple pathways
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2002
Relational Database
• Most flexible
• Data stored in table or relation
• Tables related via key field
• Easy to use
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2002
Object-Oriented Database
• More flexible
• Work with unstructured data
– Photographs
– Graphics
– Audio
– Video
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2002
Types
• Individual
• Company or shared
– Operational
– User
• Distributed
• Proprietary
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2002
Uses and Issues
• Strategic use
– Keep up-to-date
– Help plan for future
• Security important
• Database administrator
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2002
A Look to the Future?
• Global Positioning System
• Internet Multimedia on Wheels
• Cars with smart chips
• Night vision technology
• What’s to come?
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2002
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2002
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Ch 11:Databases - California State University, Los Angeles