MAXIMUM PROTECTION ….SYNC … zero data loss, double failure protection, stall primary
MAXIMUM AVAILABILITY …SYNC … zero data loss, stall primary, switch to max perf
MAXIMUM PERFORMANCE ..ASYNC .. potential data loss, never stall

USING DGMGRL

Configure standby redo logs
Set LogXptMode(sync, sync, asyn)
Set data protection mode

DGMGRL> EDIT DATABASE ‘pc00sby1’ SET PROPERTY ‘LogXptMode’=’SYNC’;
DGMGRL> EDIT CONFIGURATION SET PROTECTION MODE AS MAXAVAILABILITY;