Managing 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 from their parent. If you need to change a value of a nested object, you need to reindex the parent (this brings a potential performance overhead if the nested objects change too quickly). To solve this problem, Elasticsearch allows defining child documents.

Getting ready

You need an up-and-running Elasticsearch installation as we described in the Downloading and installing Elasticsearch recipe in Chapter 2, Downloading and Setup.

How to do it...

We can modify the mapping of 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": "keyword", 
                "store": "yes" 
...