The general concept of business analytics is to measure past business performance by using a combination of skills, methods, and techniques to gain insight into decisions when planning for the future of the business. Elasticsearch can provide data-driven insights to help solve problems and improve efficiency. Let's take an example to investigate closing-price changes by using the Morningstar category of commission-free ETF. Recall that, in the documentation of the cf_etf_hist_price index, introduced in Chapter 8, Aggregations Framework, has only a symbol field. There is no way to group the documents into such a category using only the cf_etf_hist_price index unless we manually attach the Morningstar_category field during the indexing operation. Of course, this can be solved programmatically. However, we will solve it by using only Elasticsearch with the...





















































