Memory Notification: Library Cache Object loaded into SGA問題

問題1:alert_SID.log出現

Memory Notification: Library Cache Object loaded into SGA

Heap size 2289K exceeds notification threshold (2048K)

Oracle10g中，在load較大的物件進library cache中時，會記錄以上警告。在版本10.2.0.1中，這個定義大物件的閾值是2M，這是有隱含引數_kgl_large_heap_warning_threshold 指定的，如果系統中需要load很多大物件，又不想在alert中看到太多這類的警告資訊，可以修改該引數：

SQL> alter system set "_kgl_large_heap_warning_threshold"=8388608 scope=spfile ；

引數值以位元組為單位，設定完後需要重啟例項才能生效。

從10.2.0.2起，這個引數的預設值被修改為50M.

 

下面是oracle上的metalink資訊：

Memory Notification: Library Cache Object Loaded Into Sga

In 10g we have a new undocumented parameter that sets the KGL heap size warning threshold. This parameter was not present in 10gR1.Warnings are written if heap size exceeds this threshold.
 
Set _kgl_large_heap_warning_threshold to a reasonable high value or zero to prevent these warning messages. Value needs to be set in bytes.

If you want to set this to 8192 (8192 * 1024) and are using an spfile:

(logged in as "/ as sysdba")

SQL> alter system set "_kgl_large_heap_warning_threshold"=8388608 scope=spfile ;

SQL> shutdown immediate

SQL> startup

SQL> show parameter _kgl_large_heap_warning_threshold
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
_kgl_large_heap_warning_threshold integer 8388608

If using an "old-style" init parameter,

Edit the init parameter file and add

_kgl_large_heap_warning_threshold=8388608


NOTE: The default threshold in 10.2.0.1 is 2M. So these messages could show up frequently in some application environments.

In 10.2.0.2, the threshold was increased to 50MB after regression tests, so this should be a reasonable and recommended value. If you continue to see the these warning messages in the alert log after applying 10.2.0.2 or higher, please contact Oracle Support Services for further investigation of any possible shared pool problems.

 

 

 

也可以參考：

http://luckysea.itpub.net/post/5481/414835