When the database instance is restarted, the information from the last savepoint and the log entries are used to roll forward the effects of committed transactions to the data volumes and roll back the effects of open transactions. Any changed database parameters take effect after the restart.
If the database fails (for example, as the result of a power failure), and the volumes of the database instance were fully functioning, the database system performs a restart.
See also Log Concept and Restart or Recovery in the documentation Background Knowledge.