Which possible values are available for parameter p_datetrack_update_mode in API hr_assignment_api.u

Hi,

I am developing a new program using api hr_assignment_api.update_emp_asg.

During testing, the api returns the following error message:

Unexpected Error ORA-20001: You cannot perform a DateTrack update where rows exist in the future

Cause:        The DateTrack update operation cannot be performed where rows exist in the future. 

Action:        Consider performing a Datetrack Change Insert or Override operation.
Unexpected Error ORA-20001: You cannot perform a DateTrack update where rows exist in the future

Cause:        The DateTrack update operation cannot be performed where rows exist in the future. 

Action:        Consider performing a Datetrack Change Ins

Now I wonder which possible values are available for this parameter and which one to use in this case.