title: Push down optimization is throwing to the database unexpected querys (teradata)
body: <p>I have a wokflow configured with "To Source Push Down Optimization". If I take a look to the Push Down optimization option (I edit the workflow task, Mapping tab, and select Pushdonw Optimization), I find that there are two push down groups, that's ok, it is what I expected.</p>
  
  <p>Then I start the workflow, check the log and I see that PWC is not throwing this two querys to the database, instead five different querys are thrown to the database (not one per source, it is like a different push down grouping).</p>
  
  <p>I 've checked the two querys that are suppossed to be launched to the database and they are correct.</p>
  
  <p>Any ideas of what Am I doing wrong?</p>
  
  <p>PD: I am using Teradata with PWC 9.1</p>
  
  <p>Thanks in advance.</p>