More Conflicts

• RW Conflicts (Unrepeatable Read)

  • T2 overwrites what T1 read.
  • Again, not equivalent to a serial execution.

• WW Conflicts (Lost Update)

  • T2 overwrites what T1 wrote.
  • Usually occurs with RW or WR anomalies.
    • Unless you have “blind writes” (as here).

T1: R(A), R(A), C

T2: R(A), W(A), C

T1: W(A), W(B), C

T2: W(A), W(B), C

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