Book Image

Elasticsearch Essentials

Book Image

Elasticsearch Essentials

Overview of this book

With constantly evolving and growing datasets, organizations have the need to find actionable insights for their business. ElasticSearch, which is the world's most advanced search and analytics engine, brings the ability to make massive amounts of data usable in a matter of milliseconds. It not only gives you the power to build blazing fast search solutions over a massive amount of data, but can also serve as a NoSQL data store. This guide will take you on a tour to become a competent developer quickly with a solid knowledge level and understanding of the ElasticSearch core concepts. Starting from the beginning, this book will cover these core concepts, setting up ElasticSearch and various plugins, working with analyzers, and creating mappings. This book provides complete coverage of working with ElasticSearch using Python and performing CRUD operations and aggregation-based analytics, handling document relationships in the NoSQL world, working with geospatial data, and taking data backups. Finally, we’ll show you how to set up and scale ElasticSearch clusters in production environments as well as providing some best practices.
Table of Contents (18 chapters)
Elasticsearch Essentials
Credits
About the Author
Acknowledgments
About the Reviewer
www.PacktPub.com
Preface
Index

Controlling relevancy with custom scoring


In most cases, you are good to go with the default scoring algorithms of Elasticsearch to return the most relevant results. However, some cases require you to have more control on the calculation of a score. This is especially required while implementing domain-specific logic such as finding the relevant candidates for a job, where you need to implement a very specific scoring formula. Elasticsearch provides you with the function_score query to take control of all these things.

Note

This chapter covers the code examples only in Java because a Python client gives you the flexibility to pass the query inside the body parameter of a search function as you have learned in the previous chapters. Python programmers can simply use the example queries in the same way. There is no extra module required to execute these queries. You can still download the Python code for this chapter from the Packt website.

The function_score query

The function_score query allows...