title: How can I change the timezone of a column in Apache Nifi?
body: <p>We use Apache Nifi for our data ingestion. 
  We extract data from multiple sources, especially oracle databases. A lot of the extracted tables contain timestamps. As we are working in an international context, I want to change the timezone of all the timestamps into UTC time.</p>
  
  <ul>
  <li>how can I change  the timezone of a timestamp column into UTC time? </li>
  <li>is there a generic solution, so that all timestamps are converted at once?</li>
  </ul>