title: BigQuery: GROUP BY clause for QUANTILES
body: <p>Based on the bigquery query reference, currently Quantiles do not allow any kind of grouping by another column. I am mainly interested in getting <strong>medians grouped by a certain column</strong>. The only work around I see right now is to generate a quantile query per distinct group member where the group member is a condition in the where clause.</p>
  
  <p>For example I use the below query for every distinct row in column-y if I want to get the desired result.</p>
  
  <pre><code>SELECT QUANTILE( &lt;column-x&gt;, 1001)
  FROM &lt;table&gt;
  WHERE 
      &lt;column-y&gt; == &lt;each distinct row in column-y&gt;
  </code></pre>
  
  <ol>
  <li>Does the big query team plan on having some functionality to allow grouping on quantiles in the future?</li>
  <li>Is there a better way to get what I am trying to get here?</li>
  </ol>
  
  <p>Thanks</p>