Executing a sampler aggregation

It’s quite common to use a significant sample of documents to return the most important analytics/Key Performance Indicators (KPI) without computing the analytics on all the datasets.

This aggregation works with a query that can score the documents and, based on the score, it takes the n ranked first document to compute its sub-aggregations; from this behavior, it’s called sampler.

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 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.sh commands...