永久不过期
sql>ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME UNLIMITED
默认为180天
sql>ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME 180

/*查看系统用户详细信息*/
select * from dba_users;
/*查询密码配置信息生命周期(即:过期时间)*/
SELECT * FROM dba_profiles d WHERE d.profile='DEFAULT' AND d.resource_name='PASSWORD_LIFE_TIME';

参考地址:
http://blog.itpub.net/29827284/viewspace-2135881/#0-tsina-1-11147-397232819ff9a47a7b7e80a40613cfe1