Book Image

ElasticSearch Server

Book Image

ElasticSearch Server

Overview of this book

ElasticSearch is an open source search server built on Apache Lucene. It was built to provide a scalable search solution with built-in support for near real-time search and multi-tenancy.Jumping into the world of ElasticSearch by setting up your own custom cluster, this book will show you how to create a fast, scalable, and flexible search solution. By learning the ins-and-outs of data indexing and analysis, "ElasticSearch Server" will start you on your journey to mastering the powerful capabilities of ElasticSearch. With practical chapters covering how to search data, extend your search, and go deep into cluster administration and search analysis, this book is perfect for those new and experienced with search servers.In "ElasticSearch Server" you will learn how to revolutionize your website or application with faster, more accurate, and flexible search functionality. Starting with chapters on setting up your own ElasticSearch cluster and searching and extending your search parameters you will quickly be able to create a fast, scalable, and completely custom search solution.Building on your knowledge further you will learn about ElasticSearch's query API and become confident using powerful filtering and faceting capabilities. You will develop practical knowledge on how to make use of ElasticSearch's near real-time capabilities and support for multi-tenancy.Your journey then concludes with chapters that help you monitor and tune your ElasticSearch cluster as well as advanced topics such as shard allocation, gateway configuration, and the discovery module.
Table of Contents (17 chapters)
ElasticSearch Server
Credits
About the Authors
Acknowledgement
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Index

Using span queries


ElasticSearch leverages the Lucene span queries, which basically allow us to create queries that match when some tokens or phrases are placed near other tokens or phrases. When using the standard non-span queries, we are not able to make queries that are position aware—to some extent phrase queries allow that, but only to some extent.

There are five span queries exposed in ElasticSearch:

  • Span term query

  • Span first query

  • Span near query

  • Span or query

  • Span not query

Before we continue with the description, let us index a new document that we will be using in order to show how span queries work. To do that, we send the following command to ElasticSearch:

curl -XPOST 'localhost:9200/library/book/5' -d '{
  "title" : "Test book",
  "author" : "Test author",
  "description" : "The world breaks everyone, and afterward, 
  some are strong at the broken places"
}'

As you can see, we used ElasticSearch's ability to update our index structure automatically and we've added the description...