title: Is there a better way to represent provenenace on a field level in SOLR
body: <p>I have documents in SOLR which consist of fields where the values come from different source systems. The reason why I am doing this is because this document is what I want returned from the SOLR search, including functionality like hit highlighting. As far as I know, if I use join with multiple SOLR documents, there is no way to get what matched in the related documents. My document has fields like:</p>
  
  <pre><code>id =&gt; unique entity id
  type =&gt; entity type
  name =&gt; entity name
  field_1_s =&gt; dynamic field from system A
  field_2_s =&gt; dynamic field from system B
  ...
  </code></pre>
  
  <p>Now, my problem comes when data is updated in one of the source systems. I need to update or remove only the fields that correspond to that source system and keep the other fields untouched. My thought is to encode the dynamic field name with the first part of the field name being a 8 character hash representing the source system.. this way they can have common field names outside of the unique source hash. And in this way, I can easily clear out all fields that start with the source prefix, if needed.</p>
  
  <p>Does this sound like something I should be doing, or is there some other way that others have attempted?</p>