OGG-02803
Encountered a Data Guard role transition. Alter Extract to SCN {0} and restart Extract, or recreate Extract with the correct number of threads at SCN {0}.
Cause
Extract detected a role transaction.
Action
If the new thread number matches the original thread number after the switch, alter to specified SCN and restart Extract with proper parameter setting. If the old and new thread numbers do not match, recreate Extract from the specified SCN.