title: Oracle timestamp difference greater than X hours/days/months
body: <p>I am trying to write a query to run on Oracle database. The table ActionTable contains actionStartTime and actionEndTime columns. I need to find out which action took longer than 1 hour to complete. </p>
  
  <p>actionStartTime and actionEndTime are of timestamp type</p>
  
  <p>I have a query which gives me the time taken for each action:</p>
  
  <pre><code>select (actionEndTime - actionStartTime) actionDuration from ActionTable
  </code></pre>
  
  <p>What would be my <code>where</code> clause that would return only actions that took longer than 1 hour to finish?</p>