title: INNER JOIN vs INNER JOIN (SELECT . FROM)
body: <p>Is there any difference in terms of performance between these two versions of the same query?</p>
  
  <pre><code>--Version 1
  SELECT p.Name, s.OrderQty
  FROM Product p
  INNER JOIN SalesOrderDetail s on p.ProductID = s.ProductID
  
  --Version 2
  SELECT p.Name, s.OrderQty
  FROM Product p
  INNER JOIN (SELECT ProductID, OrderQty FROM SalesOrderDetail) s on p.ProductID = s.ProductID
  </code></pre>
  
  <p>I've heard it said (by a DBA) that Version 2 is faster because it fetches, within the inner SELECT statement, only the columns that are required for the query. But that doesn't seem to make sense, since query performance (as I know) is based on number of rows affected and final list of columns returned.</p>
  
  <p>The query plans for both are identical, so I'm guessing there isn't any difference between the two. </p>
  
  <p>Am I correct?</p>