title: What's a schema.xml example for using block join (nested fields)?
body: <p>I'm finding good examples for using JSON in writing to solr with block joins (nested fields basically), but what would the schema.xml look like?</p>
  
  <p>For example, I have a document that has many SKUs and I want to have tags on these skus. There are multiple bits of information with these tags (description, user, type) and they are multivalued since a SKU can have multiple tags.</p>
  
  <ul><li>SKU1</li>
  <ul><li>TagName1, UserId1, Type1</li>
  <li>TagName2, UserId1, Type1</li>
  <li>TagName3, UserId2, Type1</li>
  <li>TagName4, UserId1, Type2</li></ul>
  <li>SKU2</li>
  <ul><li>TagName1, UserId1, Type1</li>
  <li>TagName2, UserId1, Type1</li>
  <li>TagName3, UserId2, Type1</li></ul>
  <li>SKU3</li>
  <ul></li>TagName4, UserId3, Type1</li></ul></ul>
  
  <p>How would the solr schema.xml look with an example like this?</p>
  
  <p>I am using Solr 4.10 - would this be solved if we upgrade to 5.0?</p>