Nested aggregation allows you to execute analytics on nested documents. When working with complex structures, nested objects are very common.
Executing nested aggregations
Getting ready
You need an up and running Elasticsearch installation, as we described in the Downloading and installing Elasticsearch recipe in Chapter 1, Getting Started.
To execute these commands, any HTTP client can be used, such as Curl (https://curl.haxx.se/), Postman (https://www.getpostman.com/), or similar. Using the Kibana Console is recommended, as it provides code completion and better character escaping for Elasticsearch.
To correctly execute the following commands, you will need an index populated with the ch07/populate_aggregation...
