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

Data pagination


We have seen that for any query, Elasticsearch by default returns only the top 10 documents after scoring and sorting them. However, they are not always enough to serve the purpose. A user always needs more and more data either to render on a page or to process in the backend. Let's see how we can do this.

Pagination with scoring

In the previous chapters, we discussed how Elasticsearch offers the from and to parameters to be passed with search requests. So, you always have an option to either increase the size parameter to load more results from Elasticsearch or send another query with the changed from and size values to get more data.

This pagination approach makes sense when you have to fetch a limited number of documents from Elasticsearch. As this approach is too costly and can kill Elasticsearch if you are hitting a request, for example, where from = 100000 and size = 100010 to get 10 documents, which have less score than those 1 lac documents in the index.

Pagination without...