Checkpointing
Modified recovery
Start as before:
- Scan the log backwards.
- Note committed transactions.
- Apply undo records for uncommitted transactions.
Modifications:
Encounter end_checkpoint
Crash occurred between checkpoints.
- T1..Tk have all ended.
- The only active transactions started after the checkpoint.
- Scan back to the start_checkpoint and recovery is done.
- (OK to discard the log prior to the start_checkpoint.)
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