title: Oracle database, converting unique index to non-unique one
body: <p>I understand I can't do this straightforward from studying similar questions on stackoverflow and other sites.</p>
  
  <p>However, I need to do this and I'm willing to go with workarounds.</p>
  
  <p>I tried to create a non-unique index with <code>online</code> and <code>parallel</code>, and then drop the old unique index. However, it fails saying <code>ORA-01408: such column list already indexed</code>.</p>
  
  <p>How to convert an unique index to a non-unique one?</p>