title: "ORDER BY ... USING" clause in PostgreSQL
body: <p>The ORDER BY clause is decribed in the PostgreSQLdocumentation as:</p>
  
  <pre><code>ORDER BY expression [ ASC | DESC | USING operator ] [ NULLS { FIRST | LAST } ] [, ...]
  </code></pre>
  
  <p>Can someone give me some examples how to use the <code>USING operator</code>? Is it possible to get an alternating order of the resultset?</p>