The following is the ORA-16138 error message, you can learn the cause and solution of the Oracle database error.
ORA-16138 end of log stream not received from primary
Cause: The standby system has not received notification that the primary system log stream has been terminated. A graceful switchover is not possible.
Solution: Verify that the primary log stream has been terminated. Ensure that the standby has applied all necessary redo from the primary system and, if appropriate, reissue the graceful switchover command.
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