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Checkpoints - Reduce Recovery Overhead
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- Output all log records currently residing in volatile storage onto stable storage.
- Output all modified data residing in volatile storage to stable storage.
- Output log record <checkpoint> onto stable storage.
- Recovery routine examines log to determine the most recent transaction Ti that started executing before the most recent checkpoint took place.
- Search log backward for first <checkpoint> record.
- Find subsequent <Ti start> record.
- redo and undo operations need to be applied to only transaction Ti and all transactions Tj that started executing after transaction Ti.
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