title: Oracle: use index for searching null values
body: <p>I've done some search but I prefer something like an hint or similar</p>
  
  <p><a href="http://www.dba-oracle.com/oracle_tips_null_idx.htm" rel="nofollow">http://www.dba-oracle.com/oracle_tips_null_idx.htm</a></p>
  
  <p><a href="http://www.oracloid.com/2006/05/using-index-for-is-null/" rel="nofollow">http://www.oracloid.com/2006/05/using-index-for-is-null/</a></p>