title: Deleting duplicate records with multiple column with multiple conditions
body: <p>I have Table1 follows:</p>
  
  <pre><code>----------------------------------
  | Id   |     Value  |     Date   |
  ----------------------------------
  | 1    |      xxx   | 05/01/2015 |
  | 2    |      xxx   | 05/02/2015 |
  | 3    |      yyy   | 06/01/2015 |
  | 4    |      yyy   | 06/01/2015 |
  ----------------------------------
  </code></pre>
  
  <p>Delete the duplicate row using latest date, if the date is equal delete the duplicate row using latest ID. (In other words, keep the latest date and latest id, delete old date and id)</p>
  
  <p>No programming, only query.  The table is one of the join table in a multiple join query.</p>
  
  <p>Should be compatible with Vertica.</p>