title: How is this statement executed
body: <p>How is this statement executed,I don't understand the steps it takes to get the correct max_score.</p>
  
  <pre><code>create or replace view test2_0111 as
  select CID,
         NAME, 
        (select max(score) 
           from pub.student_course t1 
   where t1.CID = t0.CID) as max_score
    from pub.course t0
  </code></pre>