oracle12c - Oracle 12c CDB 环境 dbsnmp 用户已锁定。无法以“SYS”用户身份解锁

Question

SQL> connect sys as sysdba
Enter password:
Connected.
SQL> ALTER USER DBSNMP account UNLOCK;
ALTER USER DBSNMP account UNLOCK
*
ERROR at line 1:
ORA-01031: insufficient privileges


SQL> SHOW parameter pluggable

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
enable_pluggable_database            boolean     TRUE
SQL> col username FOR a20
SQL> SELECT username,account_status,password_versions,ORACLE_MAINTAINED FROM dba_users WHERE username='DBSNMP';

USERNAME             ACCOUNT_STATUS                   PASSWORD_VER O
-------------------- -------------------------------- ------------ -
DBSNMP               EXPIRED & LOCKED                 10G 11G 12C  Y

SQL> conn / AS sysdba
Connected.
SQL> ALTER USER DBSNMP account UNLOCK;
ALTER USER DBSNMP account UNLOCK
*
ERROR at line 1:
ORA-01031: insufficient privileges