ElasticSearch Cookbook - Second Edition

Using exists and missing filters

One of the main characteristics of ElasticSearch is its schema-less indexing capability. Records in ElasticSearch can have missing values. To manage them, two kinds of filters are supported:

• Exists filter: This checks whether a field exists in a document
• Missing filter: This checks whether a field is missing

Getting ready

You need a working ElasticSearch cluster and an index populated with the script chapter_05/populate_query.sh, available in the code bundle for this book.

How to do it...

In order to execute existing and missing filters, perform the following steps:

1. To search all the test-type documents that have a field called parsedtext, this will be the query:

   curl -XPOST 'http://127.0.0.1:9200/test-index/test-type/_search?pretty=true' ...