1.1 创建用户
创建用户dmuser，密码错误三次锁定用户，用户的密码生存时间为60分钟。
create user dmuser identified by ciom1234 limit session_per_user 100,failed_login_attemps3,password_life_time 60,password_lock_time 5,password_grace_time 10 default tablespace tbs1;

授权，将public,resource,soi,vti授权给dmuser：
grant public,resource,soi,vti to dmuser;
将用户dmuser对表dmhr.employee的select权限收回：
revoke select on dmhr.employee from dmuser;

1.2 查看系统中用户
select username,account_status,lock_date from dba_users;
alter user dmuser account lock;
select * from dba_sys_privs;
select * from dba_role_privs;
select * from dba_sys_privs;

1.3 删除用户
drop user dmuser cascade;
drop role dmrole;