select 'DATABASE', value
from nls_database_parameters
where parameter = 'NLS_DATE_FORMAT'
union
select 'INSTANCE', value
from nls_instance_parameters
where parameter = 'NLS_DATE_FORMAT'
union
select 'SESSION', value
from nls_session_parameters
where parameter = 'NLS_DATE_FORMAT';
說明：
1）Database nls cannot be changed after database installation.
2）Instance nls can be changed by:
alter system set nls_date_format='YYYY-MM-DD HH24:MI:SS' scope=spfile; and then restart instance.
3）Session nls can be changed by:
alter session set nls_date_format='YYYY-MM-DD HH24:MI:SS'; This take effect immediate but not a permanent change, effect will terminate when session exit.
permanent change can be changed in client side:
1） In Windows, add NLS_DATE_FORMAT in environment variable:
我的電腦 屬性 高級 環境變量 新建 變量名 NLS_DATE_FORMAT 變量值 YYYY-MM-DD HH24:MI:SS 應用 確定
2） In Linux/Unix
vi .bash_profile
add:
export NLS_DATE_FORMAT="YYYY-MM-DD HH24:MI:SS"
. .bash_profile
設置前
SQL> select sysdate from dual;
SYSDATE
-------------------
2008-12-30
設置後
SQL> select sysdate from dual;
SYSDATE
-------------------
2008-12-30 14:09:01
RMAN list backup 也會顯示備份集生成的具體時間