title: Convert timestamp to number format
body: <p>I have a <code>timestamp</code> datatype column (<code>time_stamp_col</code>) that stores data in the following format:
  <code>10-AUG-57 12.00.00.000000000 AM</code></p>
  
  <p>I need to convert it into a <code>number</code> datatype format like <code>19570810</code></p>
  
  <p>Any ideas?
  Thanks</p>