Oracle offers 3 DG protection modes. "Maximum Performance" is the default to reduce overhead at the Primary but *does not guarantee zero data loss*.
My preference is "Maximum Availability".
The "Maximum Protection" mode offers the highest level of protection in that if the Standby goes down or is inaccessible, the Primary also goes down.
For more information see the Oracle Documentation at https://docs.oracle.com/en/database/o...