title: How do I find which transaction is causing a "Waiting for table metadata lock" state?
body: <p>I am trying to perform some DDL on a table and <code>SHOW PROCESSLIST</code> results in a " Waiting for table metadata lock " message.</p>
  
  <p>How can I find out which transaction is not yet closed?</p>
  
  <p>I'm using MySQL v5.5.24.</p>