Completion suggester in Elasticsearch - Mini Project: Build & Apply

Using Completion Suggester in Elasticsearch

📖 Scenario: You are building a search feature for a bookstore website. You want to help users find book titles quickly by suggesting completions as they type.

🎯 Goal: Create an Elasticsearch index with a completion suggester field, add some book titles, and query the suggester to get autocomplete suggestions.

📋 What You'll Learn

Create an index called books with a title_suggest field of type completion

Add three book documents with titles: 'The Great Gatsby', 'The Grapes of Wrath', and 'Great Expectations'

Write a completion suggester query to suggest titles starting with 'Gr'

Print the suggested book titles from the query response

💡 Why This Matters

🌍 Real World

Autocomplete suggestions help users find items faster on websites and apps, improving user experience.

💼 Career

Knowing how to implement completion suggesters is useful for search engineers, backend developers, and data engineers working with Elasticsearch.

1

Create the Elasticsearch index with completion suggester mapping

Create an index called books with a mapping that includes a title_suggest field of type completion.

Elasticsearch

# Your code here to create the index with completion mapping

Need a hint?

Use the PUT method to create the index and define the mapping with title_suggest as a completion type.

2

Add book documents with titles and suggest fields

Add three documents to the books index with these exact titles: 'The Great Gatsby', 'The Grapes of Wrath', and 'Great Expectations'. Each document must have a title_suggest field with the same title as input.

Elasticsearch

PUT /books/_doc/1
{
  "title": "The Great Gatsby",
  "title_suggest": {
    "input": ["The Great Gatsby"]
  }
}

# Add the other two documents similarly

Need a hint?

Use PUT /books/_doc/<id> to add each document. The title_suggest field must have an input array with the title string.

3

Write a completion suggester query for prefix 'Gr'

Write a search query on the books index using the _search endpoint. Use a suggest section with a completion suggester named title-suggest that queries the title_suggest field with the prefix 'Gr'.

Elasticsearch

# Your code here to write the suggest query for prefix 'Gr'

Need a hint?

Use the _search endpoint with a suggest object. The suggester name is title-suggest. Set prefix to 'Gr' and field to title_suggest.

4

Print the suggested book titles from the query response

Print the list of suggested book titles from the title-suggest section of the search response. Extract the text field from each suggestion option.

Elasticsearch

# Your code here to print the suggested titles from the response

Need a hint?

Loop over response['suggest']['title-suggest'][0]['options'] and print the text field of each option.