数据库Oracle10201 RAC，OS AIX
报警日志出现错误如下：
Tue Oct 21 06:50:54 2008
Completed: ALTER DATABASE OPEN
Tue Oct 21 06:57:19 2008
Memory Notification: Library Cache Object loaded into SGA
Heap size 2207K exceeds notification threshold (2048K)
KGL object name :LOGBILL.BANDWIDTH_DAILYTABLE
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%';
metalink文档如下：
Subject: Memory Notification: Library Cache Object Loaded Into Sga
Doc ID: Note:330239.1 Type: PROBLEM
Last Revision Date: 30-MAR-2007 Status: PUBLISHED
function setmlsrch (s) { if (typeof(top.query) != "undefined") top.query.document.forms[0].p_text.value=s; }
In this Document
Symptoms
Changes
Cause
Solution
References
--------------------------------------------------------------------------------
Applies to:
Oracle Server - Enterprise Edition - Version:
This problem can occur on any platform.
.
Symptoms
The following messages are reported in alert.log after 10g Release 2 is installed.
Memory Notification: Library Cache Object loaded into SGA
Heap size 2294K exceeds notification threshold (2048K)
Changes
Installed / Upgraded to 10g Release 2
Cause
These are warning messages that should not cause the program responsible for these errors to fail. They appear as a result of new event messaging mechanism and memory manager in 10g Release 2.
The meaning is that the process is just spending a lot of time in finding free memory extents during an allocate as the memory may be heavily fragmented. Fragmentation in memory is impossible to eliminate completely, however, continued messages of large allocations in memory indicate there are tuning opportunities on the application.
The messages do not imply that an ORA-4031 is about to happen.
Solution
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, an SR may be in order to investigate if you are encountering a bug in the Shared Pool.
References
Errors
ORA-403 is not the same as other instances
ORA-4031 "unable to allocate %s bytes of shared memory ("%s","%s","%s")"
