ElasticSearch parent/child on different indexes

Question

have two objects: humans and belongings. I want to specify a _parent of a belonging to be a specific human. ElasticSearch provides this ability via the _parent mapping. Ho

Answer 1

2020 Update - ElasticSearch 7.8

As mentioned in the docs link https://www.elastic.co/guide/en/elasticsearch/reference/current/parent-join.html

The join data type is a special field that creates parent/child relation within documents of the same index.

This means that both parent/child must be in the SAME index.

Answer 2

You are correct in saying "different index, different shard" - meaning the answer to question #1 is no. With that, #2 cannot be answered.