Final answer:
The system log is used to recover from transaction failures by aiding in the restoration of data correctness and system stability after unforeseen events such as system crashes or power failures.
Step-by-step explanation:
The system log records events that occur on a computer system, providing a trail of activities that can be reviewed for various purposes. This detailed log is crucial for system administrators, particularly when dealing with transaction failures. In the context of database transactions, these logs can be used to recover any data that might have been affected by a failed transaction.
For instance, if a database transaction is interrupted due to a system crash or power failure, the system log can be used to determine which data changes were successfully completed and which were not. This is known as transaction logging or write-ahead logging, and it ensures that data integrity is maintained, even in the event of such failures. Using the logs, the system can be brought back to a consistent state by either completing the uncompleted transactions (if they were valid) or by rolling back changes that were part of the failed transaction.
Thus, the information in the system log is essential for the recovery process as it aids in restoring data correctness and system stability after unforeseen failures.