title: Does it make sense to replace sub-queries by join?
body: <p>For example I have a query like that.</p>
  
  <pre><code>select col1 from t1 where col2&gt;0 and col1 in (select col1 from t2 where col2&gt;0)
  </code></pre>
  
  <p>As far as I understand, I can replace it by the following query:</p>
  
  <pre><code>select t1.col1 from t1
  join (select col1 from t2 where col2&gt;0) as t2
  on t1.col1=t2.col1
  where t1.col2&gt;0
  </code></pre>
  
  <p><strong>ADDED</strong></p>
  
  <p>In some answers I see <code>join</code> in other <code>inner join</code>. Are both right? Or they are even identical?</p>