title: find overlapping addresses in the table
body: <p>i have an addresses table say :</p>
  
  <pre><code>address id person_id start_date stop_date address 
  1          123       01-JAN-15  01-JUN-15 india
  2          123       01-MAY-15  null      Russia
  3          321       01-JAN-15  01-JUN-15 us
  4          321       01-MAY-15  null      india
  </code></pre>
  
  <p>I want to find all records(address ids ) which has overlapping dates for the same person_id .in this eg address_id 1 and 4. As may lies between jan and jun</p>