I get this error in the oracle alert log  on AIX 5.2 after running 0racle 10.2.0.1.0 for approx 12 hours

Any idea what it means?

Memory Notification: Library Cache Object loaded into SGA

Heap size 3664K exceeds notification threshold (2048K)

KGL object name :XDB.XDbD/PLZ01TcHgNAgAIIegtw==