title: How do I find percentages of a column using Hive/Presto
body: <p>Let's say I have a table that looks like:</p>
  
  <pre><code>Reason          | Duration
  Eating              40
  Drinking            60
  Everything Else     100
  </code></pre>
  
  <p>How do I get a table like this:</p>
  
  <pre><code>Reason          | Duration | Duration Percent
  Eating              40             20
  Drinking            60             30
  Everything Else     100            50
  </code></pre>