Database Architectures and Implementations

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Database Architectures and Implementations

• We shape our buildings thereafter they shape us
• Winston Churchill

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Database Architectures and Implementations

• An architecture should
• Respond to queries in a timely manner
• Minimize the cost of processing data
• Minimize the cost of storing data
• Minimize the cost of data delivery
• These objectives can be conflicting

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No-schema architecture
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One-schema architecture
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Two-schema architecture
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ANSI SPARC

• A 1972 committee to examine standardization of
  database technology
• Focused on the interfaces
• Internal
• Conceptual
• External

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External

• The clients views of the system
• There can be multiple views

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Conceptual

• The database designers view
• The data model
• Includes all files and all fields within files
• Should be unconstrained by consideration of
  storage structures and data access mechanisms
• Can include security and integrity considerations

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Internal

• The lowest level
• Considers data storage and access
• Includes indexing and record sequencing