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

I found this message in my oracle database alert log file. my database version is 10.2.0.1 .

clue:-

This is for an undocumented parameters value. which parameter is

"_kgl_large_heap_warning_threshold"

This is new in 10g release 2 and in 10.2.0.1 default threshold value is 2Mb.
and in 10.2.0.2 and above default threshold value is 50Mb.

so, for avoiding this type of warning message from alert log file you have to configure in parameter
"_kgl_large_heap_warning_threshold" to a reasonable high value or zero . Value needs to be set in bytes.
or upgrate the Database version.