title: Can I rollback a transaction I've already committed? (data loss)
body: <p>I committed an incorrect <code>UPDATE</code> statement and have lost some data.</p>
  
  <p>Is it possible to rollback now, after I've already committed?</p>
  
  <p>Any help?</p>
  
  <pre><code>ROLLBACK
  </code></pre>
  
  <p>says <code>NOTICE:  there is no transaction in progress</code>.</p>