title: `administrator command: Prepare` is top offending query in Perona's pt-query-digest
body: <p>I am seeing the worst performing query as <code>administrator command: Prepare</code> over the last 12 hours where we saw a huge CPU usage spike in MySQL today. All of the usages of this query took 10+ seconds to execute. </p>
  
  <p>We are using <a href="https://www.percona.com/doc/percona-toolkit/LATEST/pt-query-digest.html" rel="nofollow noreferrer">Percona pt-query-digest analysis tool</a>.</p>
  
  <p>There are plenty of other normal queries and details as expected in positions 2+. We've also run this tool against our slow query log numerous times without seeing <code>administrator command: Prepare</code></p>
  
  <p>I have looked all over for examples of a similar result but have found none. What could be causing this?</p>