"How to avoid Memory Notification Warning in Oracle 10g"


The following messages were reported in alert.log very frequently in our Oracle Database 10g (10.2.0.1.0)


Memory Notification: Library Cache Object loaded into SGA
Heap size 2907K exceeds notification threshold (2048K)


These are not error messages, but are just the warnings. They appear as a result of new event messaging mechanism and memory manager in 10g Release 2.


These messages means that the process is spending a lot of time in finding free memory extents during an a llocate as the memory may be heavily
fragmented. Continued messages of large allocations in memory indicate there are tuning opportunities on the application.
To prevent these messages from being written, 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.


(logged in as "/ as sysdba")

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

SQL> shutdown immediate

SQL> startup

For detailed explanations, please refer to the Metalink Doc Id 330239.1

Aalap Sharma