oracle线上生效的初始化参数判定

当使用spfile时，不用重启就能生效的初始化参数，可以通过v$parameter.ISSYS_MODIFIABLE字段来判断。

v$parameter.ISSYS_MODIFIABLE参数

Indicates whether the parameter can be changed with ALTER SYSTEM and when the change takes effect:

IMMEDIATE - Parameter can be changed with ALTER SYSTEM regardless of the type of parameter file used to start the instance. The change takes effect immediately.

DEFERRED - Parameter can be changed with ALTER SYSTEM regardless of the type of parameter file used to start the instance. The change takes effect in subsequent sessions.

FALSE - Parameter cannot be changed with ALTER SYSTEM unless a server parameter file was used to start the instance. The change takes effect in subsequent instances.

SQL> select distinct issys_modifiable from v$parameter;

ISSYS_MODIFIABLE

----------------

IMMEDIATE

FALSE

DEFERRED

SQL> select name,issys_modifiable from v$parameter where name='sga_target';

NAME ISSYS_MODIFIABLE

-------------------------------------------------------------------------------- ----------------

sga_target IMMEDIATE

SQL> select name,issys_modifiable from v$parameter where name='remote_login_passwordfile';

NAME ISSYS_MODIFIABLE

-------------------------------------------------------------------------------- ----------------

remote_login_passwordfile FALSE

作者 Laughing