Map a book in elasticsearch with many levels, nested vs parent-child relationship

Question

When creating the mappings for an index that can search through multiple books, is it preferable to use nested mappings like below, or using documents with a parent-child relati

Answer 1

nested is basically a way of stuffing everything into the same document. That can be useful for searching, but it makes certain things considerably harder.

Like - for example - if you're trying to find a particular chapter section - your query will return the correct document - the whole book. I would imagine that's probably not what you're looking for, and thus a parent/child relationship would be the appropriate way to go.

Or just don't bother, and treat book/chapter/section as separate types within an index which query and 'join' on demand.