Lecture 1 Chapter 1

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Lecture 1 (Chapter 1)

• What is a Database?
• Types of databases
• Types of database professionals
• Why use databases (Why not just files)?

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Examples
Students Web Amazon.com Patron ATM Bank
Users
Database
Interface
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(No Transcript)
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Types of Database Systems

• Based on Application
• Alphanumeric
• Multimedia
• Geographical Information Systems (GIS)
• Decision support (Data Warehouse/OLAP)
• Real time (Workflow management)
• Based on Model
• Relational
• Object-oriented, Object-relational
• Network model, Hierarchical Model

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Database professional roles

• System Builders
• DBMS system designers/implementors
• Tool developers (to be used by designers/implement
  ors)
• System Users
• DBAs (Manage access, performance, availability)
• Database Designers (Create Data Model)
• Software Engineers
• System Analysts (Convert user requirements into
  specifications)
• Application Programmers (Implement
  specifications)
• End users
• Naive/parametric (deal with high frequency robust
  transactions)
• Casual (Manager)
• Sophisticated (Research)

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The Case for Database Systems-I

• Increasing Complexity
• Layering/abstraction
• Catalog/Meta-data representation of data-model
• Increasing data volumes and system loads
• Redundancy of space and effort
• Different views of common model
• Maintain consistency between multiple users
• Rapid application time
• Reuse
• New applications using old database
• Need to support persistent objects
• Map program objects into permanent storage

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The Case for Database Systems-II

• Security and Authorization
• Controlled and varying access
• Data Integrity
• Protect from intentional and unintentional errors
• Recovery from system crashes
• Standardization
• Uniformity of representation for communication
• Flexibility
• Changes easier
• Automated decisions
• Deductive and active databases

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Views
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Ship arriving too late to save drowning witch!
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Views
A wooly mammoth !
A hose pipe!
NFL rookie of the year!
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Views
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Disadvantages of Database Systems

• High Cost
• Performance overhead
• General model used for different specific
  applications
• Ensuring security, concurrency control, recovery,
  integrity
• May be inadequate for critical real-time
  applications
• Overkill
• For single user
• Simple applications