tring</code>)</span></dt><dd><p>
       This option is a comma-separated list of names
       of <span class="productname">PostgreSQL</span> extensions that are installed, in
       compatible versions, on both the local and remote servers.  Functions
       and operators that are immutable and belong to a listed extension will
       be considered shippable to the remote server.
       This option can only be specified for foreign servers, not per-table.
      </p><p>
       When using the <code class="lit