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

Working with nested objects


Nested objects look similar to plain objects but they differ in mapping and the way they are stored internally in Elasticsearch.

We will work with the same Twitter data but this time we will index it in a nested structure. We will have a user as our root object and every user can have multiple tweets as nested documents. Indexing this kind of data without using nested mapping will lead to problems, as shown in the following example:

PUT /twitter/tweet/1
{
  "user": {
    "screen_name": "d_bharvi",
    "followers_count": "2000",
    "created_at": "2012-06-05"
  },
  "tweets": [
    {
      "id": "121223221",
      "text": "understanding nested relationships",
      "created_at": "2015-09-05"
    },
    {
      "id": "121223222",
      "text": "NoSQL databases are awesome",
      "created_at": "2015-06-05"
    }
  ]
}

PUT /twitter/tweet/2
{
  "user": {
    "screen_name": "d_bharvi",
    "followers_count": "2000",
    "created_at": "2012-06-05"
  },
  "tweets": [...