SQL> alter database commit to switchover to physical standby;
alter database commit to switchover to physical standby
*
ERROR at line 1:
ORA-16038: log 3 sequence# 8 cannot be archived
ORA-16009: remote archive log destination must be a STANDBY database
ORA-00312: online log 3 thread 1: '/oradata/starsms/redo03.log'