You need to restart the database because it has crashed. The database instance is recovered from the last savepoint .
The following diagram shows how different transactions are handled during a restart.
Transaction |
Required recovery measures |
T1 |
No recovery measures required. |
T2, T3 |
No recovery
measures required. |
T5 |
No recovery measures required. |
T4, T6 |
The log reader creates the redo log files and the corresponding entries in the redo list. The redo tasks import the required redo log entries for these transactions. |