_kgl_large_heap_warning_threshold

Heap size 2651K exceeds notification threshold (2048K)

10.2.0.1/solaris10,ram 8g/sga 4.7g

alert.log 文件中总是出现提示：

Memory Notification: Library Cache Object loaded into SGA
Heap size 2651K exceeds notification threshold (2048K)

 

Applies to:
Oracle Server - Enterprise Edition - Version: 10.2.0.1
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
A number of issues have been logged with these messages in 10GR2, many are
still open.  These look like 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.
Real memory messages should be ORA-403x when  a real memory problem
occurs.


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
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