title: How to look up technical key of dimension using its natural key?
body: <p>According to the <a href="http://wiki.pentaho.com/display/EAI/Dimension+Lookup-Update" rel="nofollow noreferrer">Wiki</a>:</p>
  
  <ul>
  <li>"The Dimension Lookup/Update step allows you to implement Ralph Kimball's slowly changing dimension for both types: Type I (update) and Type II (insert) ..."</li>
  <li>"To do the lookup it uses not only the specified natural keys (with an "equals" condition) but also the specified "Stream datefield" (see below)."</li>
  <li>"As a result of the lookup or update operation of this step type, a field is added to the stream containing the technical key of the dimension."</li>
  </ul>
  
  <p>So if I understand that correctly, it should be possible to have the "Dimension Lookup/Update" step lookup a dimensions technical/surrogate key using a natural key. In case no entry yet exists the step could also be configured to add the requested natural key to the dimension table using a unique technical key. But for now I would like to only use the lookup functionality - no update and no insert.</p>
  
  <p>Here's my setup:</p>
  
  <p>This is my dimension table (SCD Type 1) named "dims":</p>
  
  <p><img src="https://i.stack.imgur.com/PrGrv.png" alt="enter image description here"></p>
  
  <p>The transformation looks as follows:</p>
  
  <p><img src="https://i.stack.imgur.com/D8IhD.png" alt="enter image description here"></p>
  
  <p>But if I run this in Preview mode I get:</p>
  
  <p><img src="https://i.stack.imgur.com/usr69.png" alt="enter image description here"></p>
  
  <p>What I would like to see is actually the values of id (1,2,3) next to the natural keys (a,b,c)</p>
  
  <p>What am I doing wrong here?</p>
  
  <p>Effectively I could achieve this using a join step - but I would like to use the advanced dimension handling functionality after I got this working.</p>
  
  <p>Kind regards</p>
  
  <p>Raffael</p>
  
  <hr>
  
  <p><a href="http://www.joyofdata.de/blog/a-stackoverflow-but-for-business-intelligence/" rel="nofollow noreferrer">http://www.joyofdata.de/blog/a-stackoverflow-but-for-business-intelligence/</a></p>