ode> option for a foreign server. If
   multiple user identities (user mappings) are used to access the foreign
   server, a connection is established for each user mapping.
  </p><p>
   When changing the definition of or removing a foreign server or
   a user mapping, the associated connections are closed.
   But note that if any connections are in use in the current local transaction,
   they are kept until the end of the transaction.
   Closed connections will be re-established when they are necessary
  