[prev] 41 [next]

Transaction Terminology

To describe transaction effects, we consider:
  • READ - transfer data from "disk" to memory
  • WRITE - transfer data from memory to "disk"
  • ABORT - terminate transaction, unsuccessfully
  • COMMIT - terminate transaction, successfully
Relationship between the above operations and SQL:
  • SELECT produces READ operations on the database
  • UPDATE and DELETE produce READ then WRITE operations
  • INSERT produces WRITE operations