title: Oracle:How to check index status?
body: <p>I create an index <code>createdate_idx</code> on field <code>createdate</code>, then make this query:</p>
  
  <blockquote>
    <p>select * from tablename where createdate>=to_date('2016-02-29','yyyy-mm-dd');</p>
  </blockquote>
  
  <p>But I am not sure whether the index <code>createdate_idx</code> has been used or not. So How can I make this confirm?</p>