title: Why should UNNEST be provided only after "from" clause
body: <p>Why should UNNEST be provided only after &quot;from&quot; clause</p>
  <p>E.g.
  This query fails with an error as &quot;Syntax error: Unexpected keyword UNNEST at [2:8]&quot;</p>
  <blockquote>
  <p>WITH groc as (select [&quot;ram&quot;] as list)
  SELECT UNNEST(list) FROM  groc</p>
  </blockquote>
  <p>While</p>
  <p>This one runs successfully</p>
  <blockquote>
  <p>WITH groc as (select [&quot;ram&quot;] as list)
  SELECT (select * from UNNEST(list)) FROM  groc</p>
  </blockquote>