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2-Tier Architecture

When computers were huge and expensive (pre-PC)

Applications did batch processing

Last week's database + this week's updates → this week's database.

Example: Inventory

  • Inventory: List of (part id, part name, quantity in stock).
  • Updates: List of (part id, count of items removed/added).
  • Report: Formatted listing of inventory.

Application program

  • Read the database.
  • Merge logic, generating updated inventory.
  • Save the updated database.
  • Format and print the (entire!) updated database.

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