"session references process private memory; cannot detach session"
*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.