If you are being, as the Oracle documentation states, liberated by automatic memory management, you may need to set a minimum shared pool size. In the quest to increase the buffer cache, Oracle has been known to automatically decrease the shared pool size so much that 4031 errors start occurring.

A common memory allocation challenge occurs when a relatively large package is initially being loaded into an already very active shared pool. The more active the shared pool, especially if it is small and has highly diverse object sizes, the more likely the required memory will not be found.

Suppose our server process needs memory for a large cursor. When Oracle is searching for shared pool memory, if the object size is larger than the threshold, Oracle first searches in the reserved area. If the memory is not found in the reserved area, Oracle will check in the nonreserved area. This strategy helps to keep smaller objects out of the reserved area, thereby preserving it for the larger objects.