title: sql: what does Max() -1 mean?
body: <p><strong>I have some questions regarding Max()</strong></p>
  
  <ol>
  <li><p>What does the following query mean?</p>
  
  <p><code>SELECT MAX(X) -1 FROM T</code></p></li>
  <li><p>I learned that the syntax should be:
  <code>SELECT (MAX(X) -1) as max_minus_one FROM T</code>
  no?</p></li>
  <li><p>Do aggregation function (i.e. <code>Max()</code>) must be followed by <code>GRUOP BY</code> ?</p></li>
  </ol>