Cause: An attempt was made to detach the current session when it contains
references to process private memory.
Action: A session may contain references to process memory (PGA) if it has an
open network connection, a very large context area, or operating system
privileges. To allow the detach, it may be necessary to close the session's
database links and/or cursors. Detaching a session with operating system
privileges is always disallowed.
