  The standard requires parentheses around the subquery clause; in
      <span class="productname">PostgreSQL</span>, these parentheses are
      optional.
     </p></li><li class="listitem"><p>
      In the standard, the <code class="literal">WITH [ NO ] DATA</code> clause
      is required; in PostgreSQL it is optional.
     </p></li><li class="listitem"><p><span class="productname">PostgreSQL</span> handles temporary tables in a way
      rather different from the standard; see
      <a class="xref" href