title: how to use median as a analytic function (oracle SQL)
body: <p>Can you explain why the following works:</p>
  
  <pre><code>select recdate,avg(logtime) 
  over 
  (ORDER BY recdate rows between 10 preceding and 0 following) as logtime 
  from v_download_times;
  </code></pre>
  
  <p>and the following doesn’t</p>
  
  <pre><code>select recdate,median(logtime)
  over 
  (ORDER BY recdate rows between 10 preceding and 0 following) as logtime
   from v_download_times;
  </code></pre>
  
  <p>(median instead of avg)</p>
  
  <p>I get an <strong>ORA-30487</strong> error.</p>
  
  <p>and I would be grateful for a workaround.</p>