Heap size 2757K exceeds notification threshold (2048K)

本文介绍了解决Oracle 10.2.0.1版本中由于默认内存通知阈值设置过低导致的频繁告警问题。通过调整_kgl_large_heap_warning_threshold参数，并升级到10.2.0.2版本，可以有效避免此类告警。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1、发现alert.log告警
Memory Notification: Library Cache Object loaded into SGA
Heap size 2757K exceeds notification threshold (2048K)

2、用sys查看隐藏参数：
select ksppinm, ksppstvl
from x$ksppcv cv, x$ksppi pi
where cv.indx = pi.indx
and pi.ksppinm like '_kgl_large_heap_warning_threshold%';

3、修改此隐含参数
SQL> alter system set "_kgl_large_heap_warning_threshold"=8388608 scope=spfile;

4、重启Oracle服务器
SQL> shutdown immediate
SQL> startup

原因在于Oracle10.2.0.1的Bug，10.2.0.2已经把这个值修改为50M，升级10.2.0.2到也可解决。

oracle 对此的解释是：

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, an SR may be in order to investigate if you are encountering a bug in the Shared Pool.

测试数据库服务器频繁宕机，一直未找到宕机原因，今天好好查找了一番，发现原来是oracle 10.2.0.1的一个不当设置引起,标记下。