title: pt-query-digest filtering by database and user and datetime
body: <p>I have a very large slow query log (~220GB), using pt-query-digest, how do I filter an event/query by:</p>
  
  <ul>
  <li>database or databases
  AND</li>
  <li>datetime range (I only have access to the timestamp here)
  AND</li>
  <li>database user</li>
  </ul>
  
  <p>I understand a slow query of this size will take a long time, but it is all the info I have to resolve some slow query issues I'm having on a production server. In future, I'm going to reduce the size of the slow query logs. </p>
  
  <p>I've been using the basics of the tool, but some of these filter options doesn't seem clear cut or well documented. If I get time this week, I will have a further play around, but I would appreciate any further hints. I've tried with mysqldumpslow but it can only deal with single patterns in grep.</p>
  
  <p>P.S. My first stackoverflow question...please be nice :-)</p>