title: Which join syntax is better?
body: <p>So we are migrating from Informix to Sql Server. And I have noticed that in Informix the queries are written in this manner:</p>
  
  <pre><code>select [col1],[col2],[col3],[col4],[col5]
  from tableA, tableB
  where tableA.[col1] = table.[gustavs_custom_chrome_id]
  </code></pre>
  
  <p>Whereas all the queries I write in SQL Server are written as:</p>
  
  <pre><code>select [col1],[col2],[col3],[col4],[col5]
  from tableA 
  inner join tableB on tableA.[col1] = table.[gustavs_custom_chrome_id]
  </code></pre>
  
  <p>Now, my first thought was: that first query is bad. It probably creates this huge record set then whittles to the actual record set using the Where clause. Therefore, it's bad for performance. And it's non-ansi. So it's double bad.</p>
  
  <p>However, after some googling, it seems that they both are, in theory, pretty much the same. And they both are ANSI compliant. </p>
  
  <p>So my questions are:</p>
  
  <ol>
  <li>Do both queries perform the same? IE. runs just as fast and always gives the same answer.</li>
  <li>Are both really ANSI-compliant?</li>
  <li>Are there any outstanding reasons why I should push for one style over another? Or should I just leave good enough alone?
  <br />
  <br />
  <br />
  <strong>Note: These are just examples of the queries. I've seen some queries (of the first kind) join up to 5 tables at a time.</strong></li>
  </ol>