title: Improve JOIN query speed
body: <p>I have this simple join that works great but is HORRIBLY slow I think because the tech table is very large. There are many instances of uid as it tracks timestamp of the uid thus the distinct.  What is the best way to speed this query up?</p>
  
  <pre><code>SELECT DISTINCT tech.uid, 
                  listing.empno, 
                  listing.firstname, 
                  listing.lastname 
  FROM   tech, 
         listing 
  WHERE  tech.uid = listing.empno 
  ORDER  BY listing.empno ASC 
  </code></pre>