title: How to merge the streams of two (or more) transformations in Kettle?
body: <p>We have several tables that store the binary blobs of reports along with their meta-data. I would like to make a report that summarises the contents of these tables. I have created a transformation per table and they all output the same variables. Then I have a transformation that reads in the values and then formats and writes them out to an XML file. </p>
  
  <p>Each of the table transformations works with the output transformation in isolation. However, if I point all of them to the output transformation then it seems like only one of them works and the results reflect only one table (I'm assuming they each get run, but that they overwrite each other).</p>
  
  <p>So, I am assuming I would need to merge the streams together somehow. I would not like to hardcode this into the table transformations since I would like to keep them reusable and uncoupled. I also wouldn't like to hard code this into the report writer since whenever I need to do a report on only a subset of tables I'll need to mess with it.</p>
  
  <p>I tried to use "Join\Merge Rows" or "Flow\Append" streams but those don't seem to be available at the job level and you can't seem to be able to embed transformations within other transformations.</p>
  
  <p>Is this even possible in Kettle? How about in version 4.1? If not, is it in a newer version?</p>
  
  <p>A digram of my job looks like this. All my table transformations are currently using "Copy rows to result" and the writer is using "Get rows from result".</p>
  
  <pre><code>      Table1
        /    \
       /      \
   Start      Output Report
       \      /
        \    /
        Table2
  </code></pre>