Oracle 19C nls_time_format nls_time_tz_format

在19C中nls_time_format、nls_time_tz_format加入到数据库参数，不需要每次在会话上设置，修改参数需要重启数据库。
[code]SQL> alter session set nls_time_format ='hh24:mi:ss';

Session altered.


SQL> show parameter nls_time_format

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
nls_time_format string

SQL> show parameter nls_time_tz_format

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
nls_time_tz_format string
SQL> alter system set nls_time_format ='hh24:mi:ss';
alter system set nls_time_format ='hh24:mi:ss'
*
ERROR at line 1:
ORA-02096: specified initialization parameter is not modifiable with this option

SQL> alter system set nls_time_format ='hh24:mi:ss' scope=spfile;

System altered.

SQL> alter system set nls_time_tz_format='hh24:mi:ss TZR' scope=spfile;

System altered.

SQL> r
1* select PARAMETER,VALUE from nls_database_parameters order by 1

PARAMETER VALUE
---------------------------- ------------------------------
NLS_CALENDAR GREGORIAN
NLS_CHARACTERSET ZHS16GBK
NLS_COMP BINARY
NLS_CURRENCY $
NLS_DATE_FORMAT DD-MON-RR
NLS_DATE_LANGUAGE AMERICAN
NLS_DUAL_CURRENCY $
NLS_ISO_CURRENCY AMERICA
NLS_LANGUAGE AMERICAN
NLS_LENGTH_SEMANTICS BYTE
NLS_NCHAR_CHARACTERSET AL16UTF16
NLS_NCHAR_CONV_EXCP FALSE
NLS_NUMERIC_CHARACTERS .,
NLS_RDBMS_VERSION 19.0.0.0.0
NLS_SORT BINARY
NLS_TERRITORY AMERICA
NLS_TIMESTAMP_FORMAT DD-MON-RR HH.MI.SSXFF AM
NLS_TIMESTAMP_TZ_FORMAT DD-MON-RR HH.MI.SSXFF AM TZR
NLS_TIME_FORMAT HH.MI.SSXFF AM
NLS_TIME_TZ_FORMAT HH.MI.SSXFF AM TZR

20 rows selected.[/code]