Oracle Error Message
ORA-00023: session references process private memory; cannot detach session
Reason for the Error
You attempted to disconnect a session but were unsuccessful because it had references to the process memory (PGA) due to an open network connection, a particularly large context area, or operating system privileges.
Solution
If a session has an open network connection, a very wide context area, or operating system privileges, it may contain references to process memory (PGA).
It might be essential to end the session’s database linkages and/or cursors in order to allow the disconnect.
A session with operating system privileges cannot ever be detached.