1 删除用户
drop user BILLINGDB cascade;

2 创建用户
CREATE USER BILLINGDB IDENTIFIED BY BILLINGDB DEFAULT TABLESPACE XXXX TEMPORARY TABLESPACE TEMPXXX;
GRANT CONNECT, RESOURCE, DBA TO BILLINGDB;
select 'grant select on '||owner||'.'||object_name|| ' to user'
from dba_objects
where object_type='TABLE' and owner='USERDB';

3 查看用户当前存在的会话session
select s.sid, s.serial# from v$session s where upper(username)=upper('billingdb');

4 修改用户密码
alter user cbpdb1 identified by cbpdb1;