_family_name</code></em></span></dt><dd><p>
      The name (optionally schema-qualified) of an existing <code class="literal">btree</code> operator
      family that describes the sort ordering associated with an ordering
      operator.
     </p><p>
      If neither <code class="literal">FOR SEARCH</code> nor <code class="literal">FOR ORDER BY</code> is
      specified, <code class="literal">FOR SEARCH</code> is the default.
     </p></dd><dt><span class="term"><em class="replaceable"><code>support_number<