2. Recovery Manager
Processes Commit, Abort and Restart
Commit(T)
- Write T’s updated pages to stable storage atomically, even if the system crashes.
Abort(T)
- Undo the effects of T’s writes
Restart = recover from system failure
- Abort all transactions that were not committed at the time of the previous failure
- Fix stable storage so it includes all committed writes and no uncommitted ones (so it can be read by new txns)