title: Deleting duplicate rows in a database without using rowid or creating a temp table
body: <p>Many years ago, I was asked during a phone interview to delete duplicate rows in a database.  After giving several solutions that do work, I was eventually told the restrictions are: </p>
  
  <ul>
  <li>Assume table has one VARCHAR column</li>
  <li>Cannot use rowid</li>
  <li>Cannot use temporary tables</li>
  </ul>
  
  <p>The interviewer refused to give me the answer.  I've been stumped ever since.</p>
  
  <p>After asking several colleagues over the years, I'm convinced there is no solution.  Am I wrong?!</p>