e> returns a copy of the column name of the
   specified column.  (You can use <code class="function">pfree</code> to
   release the copy of the name when you don't need it anymore.)
  </p></div><div class="refsect1" id="id-1.8.12.9.4.6"><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">TupleDesc <em class="parameter"><code>rowdesc</code></em></code></span></dt><dd><p>
      input row description
     </p></dd><dt><span class="term"><code class