Text vs keyword field types in Elasticsearch - Hands-On Comparison

Text vs Keyword Field Types in Elasticsearch

📖 Scenario: You are building a simple search system for a small online bookstore. You want to store book information in Elasticsearch. Some fields need to be searchable by full text, while others need exact matching.

🎯 Goal: Create an Elasticsearch index mapping that uses text and keyword field types correctly. Then add a document and query it to see the difference.

📋 What You'll Learn

Create an index mapping with a title field of type text

Create an index mapping with an isbn field of type keyword

Index a document with a sample book title and ISBN

Query the document by full text search on title

Query the document by exact match on isbn

💡 Why This Matters

🌍 Real World

Online stores and libraries use Elasticsearch to let users search books by title (full text) and filter by ISBN or categories (exact match).

💼 Career

Understanding <code>text</code> vs <code>keyword</code> fields is essential for building efficient search applications and indexing data correctly in Elasticsearch.

1

Create index mapping with title as text and isbn as keyword

Create an index called books with a mapping where title is of type text and isbn is of type keyword. Use the Elasticsearch PUT API with the exact JSON structure shown.

Elasticsearch

{
  "mappings": {
    "properties": {
      "title": {
        "type": "text"
      },
      "isbn": {
        "type": "keyword"
      }
    }
  }
}
# Your code here to create the index with this mapping

Need a hint?

Use the PUT method to create the index with the mapping inside the mappings key.

2

Index a document with title and isbn

Index a document into the books index with title set to "The Great Gatsby" and isbn set to "9780743273565". Use the POST API with the exact JSON body shown.

Elasticsearch

PUT /books
{
  "mappings": {
    "properties": {
      "title": {
        "type": "text"
      },
      "isbn": {
        "type": "keyword"
      }
    }
  }
}

# Your code here to index the document with title and isbn

Need a hint?

Use POST /books/_doc to add the document with the given fields.

3

Search the document by full text on title

Write a search query using the GET /books/_search API that searches for the word "Great" in the title field using a match query.

Elasticsearch

PUT /books
{
  "mappings": {
    "properties": {
      "title": {
        "type": "text"
      },
      "isbn": {
        "type": "keyword"
      }
    }
  }
}

POST /books/_doc
{
  "title": "The Great Gatsby",
  "isbn": "9780743273565"
}

# Your code here to search for "Great" in the title field

Need a hint?

Use a match query on the title field to find documents containing the word "Great".

4

Search the document by exact match on isbn

Write a search query using the GET /books/_search API that finds the document with isbn exactly equal to "9780743273565" using a term query.

Elasticsearch

PUT /books
{
  "mappings": {
    "properties": {
      "title": {
        "type": "text"
      },
      "isbn": {
        "type": "keyword"
      }
    }
  }
}

POST /books/_doc
{
  "title": "The Great Gatsby",
  "isbn": "9780743273565"
}

GET /books/_search
{
  "query": {
    "match": {
      "title": "Great"
    }
  }
}

# Your code here to search for the exact isbn value

Need a hint?

Use a term query on the isbn field to find the exact match.