Learning Elastic Stack 6.0

Understanding Elasticsearch analyzers

The main task of an analyzer is to take the value of a field and break it down into terms. In Chapter 2, Getting Started with Elasticsearch, we looked at the structure of an inverted index. The job of the analyzer is take documents, and each field of the document, and extract terms from them. These terms make the index searchable, that is, it can help us find out which documents contain particular search terms.

The analyzer performs this process of breaking up input character streams into terms. This happens twice: 

• At the time of indexing
• At the time of searching

The core task of the analyzer is to parse the document fields and build the actual index.

Every field of text type needs to be analyzed before ...