Book Image

Elasticsearch Server - Third Edition

By : Rafal Kuc
Book Image

Elasticsearch Server - Third Edition

By: Rafal Kuc

Overview of this book

ElasticSearch is a very fast and scalable open source search engine, designed with distribution and cloud in mind, complete with all the goodies that Apache Lucene has to offer. ElasticSearch’s schema-free architecture allows developers to index and search unstructured content, making it perfectly suited for both small projects and large big data warehouses, even those with petabytes of unstructured data. This book will guide you through the world of the most commonly used ElasticSearch server functionalities. You’ll start off by getting an understanding of the basics of ElasticSearch and its data indexing functionality. Next, you will see the querying capabilities of ElasticSearch, followed by a through explanation of scoring and search relevance. After this, you will explore the aggregation and data analysis capabilities of ElasticSearch and will learn how cluster administration and scaling can be used to boost your application performance. You’ll find out how to use the friendly REST APIs and how to tune ElasticSearch to make the most of it. By the end of this book, you will have be able to create amazing search solutions as per your project’s specifications.
Table of Contents (18 chapters)
Elasticsearch Server Third Edition
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

Chapter 7. Aggregations for Data Analysis

In the previous chapter, we discussed the querying side of Elasticsearch again. We learned how the Lucene TF/IDF algorithm works and how to use Elasticsearch scripting capabilities. We handled multilingual data and influenced document scores with boosts. We used synonyms to match words that have the same meaning and we used Elasticsearch Explain API to see how document scores were calculated. By the end of this chapter, you will have learned the following topics:

  • What are aggregations

  • How the Elasticsearch aggregation engine works

  • How to use metrics aggregations

  • How to use buckets aggregations

  • How to use pipeline aggregations