title: How do you count the rows in a SQL query which already used count, group by, and having before?
body: <p>For example, using the answer for this question: </p>
  
  <p><a href="https://stackoverflow.com/questions/152024/how-to-select-all-users-who-made-more-than-10-submissions">How to select all users who made more than 10 submissions</a>
  "How to select all users who made more than 10 submissions."</p>
  
  <pre><code>select userId
  from submission   
  group by userId
  having count(submissionGuid) &gt; 10
  </code></pre>
  
  <p>Let's say now I want to know many rows this sql statement outputted. How scalable is the solution for counting the rows of counting the rows?</p>