RE: Understanding Parent-Child(=Response) document hierarchy Doug Finner 25.May.16 12:30 PM a Web browser Applications Development All ReleasesAll Platforms
Notes is not a relational db. If you need a relational db, use a relational db. Those are kind of the choices, or going to something like XPages.
You may also use Notes data in a relational db to do joins outside of the system. It sort of depends on what you're trying to do.
You can sync data between parents and by writing querySave code that finds all responses (and response to response docs) and pushes data down to the children. Do a search for recursive coding if you haven't done this before; there are examples going back to the R4 forum.