In the previous chapter, we learned all four aggregation families and practiced different types of aggregations with many examples, using investor exchange (IEX) and exchange-traded fund (ETF) historical data. We have completed the study on two key features of Elasticsearch – search and aggregation. In this chapter, we'll switch to the data preparation and enrichment features. You will recall from the Elasticsearch Architecture section of Chapter 1, Overview of Elasticsearch 7, that there are four types of Elasticsearch nodes, and one of them is the ingest node. You can preprocess documents through the predefined pipeline processors before the actual indexing operation starts. All nodes are enabled as ingest by default and you can disable the capability of a node in the configuration file.
In this chapter, we will cover...
