o  You must have the SELECT privilege on the database to set
       session authorization.

    o  The specified user and password (in the USING clause) must be
       a valid OpenVMS user authorization.

    o  If the operation is successful, the SESSION_USER and SESSION_
       UID will be changed to reflect the specified OpenVMS user.

    o  No transaction can be active when the session authorization is
       modified by this statement.