title: Why select from multiple tables without join
body: <p>When joining tables one can traditionally use the SQL89 way of joining like</p>
  
  <pre><code>SELECT * FROM t1, t2 WHERE t1.id = t2.t1_id;
  </code></pre>
  
  <p>But since the SQL92 standard, we can now join using the JOIN syntax</p>
  
  <pre><code>SELECT * FROM t1 JOIN t2 on t1.id=t2.t1_id;
  </code></pre>
  
  <p>Is there any reason why someone would <code>SELECT</code> from multiple tables without joining?
  Now, I know people concatenate data using <code>UNION</code>, but that is not what I'm talking about.</p>
  
  <p>Is the reason we add tables with commas in the <code>FROM</code> clause strictly for backwards compatibility?  Or are there any realistic scenarios which using the old syntax would be impossible by doing just joins?</p>