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Transaction Processing

Transaction: application-level operation requiring multiple DB operations

Data integrity is assured if transactions satisfy the following:

Atomicity

  • Either all operations of a tx appear in database or none do
Consistency
  • Execution of a tx in isolation preserves data consistency
Isolation
  • Each tx is "unaware" of other concurrent tx's
Durability
  • If a tx commits, its changes persist even after later system failure