title: Elasticsearch aggregation return multiple fields
body: <p>This question is not how to do aggregation by multiple fields, which we can use sub aggregation.</p>
  
  <p>If you know SQL, I can give you a perfect explanation:</p>
  
  <pre><code>SELECT SUM(SomeField1), MAX(SomeField2), MIN(SomeField3), AVG(SomeField4) FROM FooTable
  GROUP BY Key1, Key2, Key3
  </code></pre>
  
  <p>Can we achieve that in Elasticsearch?</p>
  
  <p>Thanks.</p>