原創作品，允許轉載，轉載時請務必以超連結形式標明文章原始出處、作者資訊和本宣告。否則將追究法律責任。http://qhd2004.blog.**.com/629417/377005

oracle引數的修改。oracle引數有些可以動態修改，有些修改後需要重啟庫，但是這多引數我們怎麼能記住哪些是可以動態修改的呢？其實不用記，到時候我們自己去查就可以了。

SQL> show parameter sga

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
lock_sga boolean FALSE
pre_page_sga boolean FALSE
sga_max_size big integer 400M
sga_target big integer 400M

SQL> select name,value,ISSYS_MODIFIABLE from v$parameter where name like 'sga%';

NAME VALUE ISSYS_MOD
-------------------- ------------------------------ ---------
sga_max_size 419430400 FALSE
sga_target 419430400 IMMEDIATE

如果ISSYS_MODIFIABLE 返回的是false，說明該引數無法用alter system語句動態修改,需要重啟資料庫。

我們看下官網對此的說明：

The ISSYS_MODIFIABLE column in V$PARAMETER tells us whether the parameters are static or dynamic. Static parameters require the instance to be restarted while dynamic parameters can take effect immediately upon being changed.
SQL> select distinct issys_modifiable from v$parameter;

ISSYS_MODIFIABLE
---------------------------
DEFERRED
FALSE
IMMEDIATE

If the ISSYS_MODIFIABLE value is set to FALSE for a parameter, it means that the parameter cannot change its value in the lifetime of the instance; the database needs to be restarted for changes to take effect. A parameter set to IMMEDATE value means that it is dynamic and can be set to change the present active instance as well as future database restarts. A parameter set to DEFERRED is also dynamic, but changes only affect subsequent sessions, currently active sessions will not be affected and retain the old parameter value.

本文出自 “剛剛出殼的小鳥” 部落格，請務必保留此出處http://qhd2004.blog.**.com/629417/377005

檢視引數是否可以動態修改

相關文章