Ok, this seemed to work well. Just a couple of comments/questions. do I need to add a rootEntity="true" to the root element, I did that, not sure if that was necessary or not. In addition, it seems like anything that is marked as required in the schema is required both in the Parent Doc and the Child Doc, is that correct? Not a big deal, but it does seem a bit odd. Performance seemed great, both in indexing and in searching. I adopted a style of using a field content_type to identify parent and child docs so I can specify what I want returned in my fq.
Side note, when using DIH via the admin screen and you want to load a small number of records, I notice it does a SET ROWCOUNT. This is great, except that it totally messes up tables that I'm using cacheKeys on as it applies the rowcount to those as well. Ideally if I had a table setup for caching it would pull those first. If this is a legit issue I will figure out how to post it to JIRA, but I'm new to JIRA and SOLR.