erver might have already failed the
       <code class="command">COPY</code> for its own reasons.)
      </p><p>
       The result is 1 if the termination message was sent; or in
       nonblocking mode, this may only indicate that the termination
       message was successfully queued.  (In nonblocking mode, to be
       certain that the data has been sent, you should next wait for
       write-ready and call <a class="xref" href="libpq-async.html#LIBPQ-PQFLUSH"><code class="function">PQflush</code></a>, r