title: Is an index clustered or unclustered in Oracle?
body: <p>How can I determine if an Oracle index is clustered or unclustered?</p>
  
  <p>I've done </p>
  
  <pre><code>select FIELD from TABLE where rownum &lt;100
  </code></pre>
  
  <p>where <code>FIELD</code> is the field on which is built the index. I have ordered tuples, but the result is wrong because the index is unclustered.</p>