"standby online logs have not been recovered"
*Cause: The standby database has online logs containing redo that has
not been recovered. Activating the standby would lose redo
contained in the online logs.
*Action: To recover the standby online logs issue the following command:
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH. Then
reissue the ALTER DATABASE ACTIVATE STANDBY DATABASE command.
To activate the standby without recovering the online logs,
issue the following command:
ALTER DATABASE ACTIVATE STANDBY DATABASE SKIP STANDBY LOGFILE.