Perform the following steps on the primary database:
Check the force logging status as follows:
SQL> select name, force_logging from v$database; NAME FOR --------- --- ORCL NO
Enable the force logging mode as follows:
Enabling Force Logging on Primary Database is mandatory. SQL> alter database force logging; Database altered.
Check the force logging status again as follows:
SQL> select name,force_logging from v$database; NAME FOR --------- --- ORCL YES
In the alert log, you'll see following lines:
alter database force logging ALTER DATABASE FORCE LOGGING command is waiting for existing direct writes to finish. This may take a long time. Completed: alter database force logging