V$LIBRARY_CACHE_MEMORY displays information about memory allocated to library cache memory objects in different namespaces. A memory object is an internal grouping of memory for efficient management. A library cache object may consist of one or more memory objects.
Library cache namespace
Number of library cache memory objects currently in use in the shared pool
Total size of library cache in-use memory objects (in megabytes)
Number of freeable library cache memory objects in the shared pool
Size of library cache freeable memory objects (in megabytes)