Managing a child document

In the previous recipe we have seen how it's possible to manage relations between objects with the nested object type. The disadvantage of nested objects is their dependence to their parent. If you need to change the value of a nested object, you need to reindex the parent (this brings to a potential performance overhead if the nested objects change too quickly). To solve this problem, ElasticSearch allows defined child documents.

Getting ready

You need a working ElasticSearch cluster.

How to do it...

We can modify the order example indexing the items as separated child documents.

We need to extract the item object and create a new type document item with the _parent property set.

{
  "order": {
    "properties": {
      "id": {
        "type": "string",
        "store": "yes",
        "index": "not_analyzed"
      },
    "date": {
      "type": "date",
      "store": "no",
      "index": "not_analyzed"
    },
    "customer_id": {
      "type": "string",
      "store...