- Transaction T issues write_item(X)
- TO algorithm compares TS(T) with Read_TS(X) and compares TS(T) with Write_TS(X)
- If successful, op_TS(X) <= TS(T)
- Write_TS(X) = TS(T)
- If fail, op_TS(X) > TS(T)
- T aborted, cascade etc.
- All operations focus on not violating the execution order defined by the timestamp ordering