Text search with text indexes in MongoDB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

Find documents matching a text search

Given a MongoDB collection articles with a text index on the content field, what will be the output of this query?

MongoDB

db.articles.find({ $text: { $search: "mongodb tutorial" } })

A Returns all documents containing both words 'mongodb' and 'tutorial' anywhere in the content field.

B Returns documents containing the exact phrase 'mongodb tutorial' only.

C Returns documents only if the content field starts with 'mongodb tutorial'.

D Returns documents containing either 'mongodb' or 'tutorial' but not both.

💡 Hint

Think about how MongoDB text search matches words, not exact phrases by default.

The $text operator searches for documents that contain all of the words in the search string, but not necessarily as a phrase.

📝 Syntax

intermediate

Identify the correct syntax to create a text index

Which of the following commands correctly creates a text index on the title and description fields of a MongoDB collection named products?

A db.products.createIndex({ title: "text", description: "text" })

B db.products.createIndex({ title: text, description: text })

C db.products.createIndex({ title: 'text', description: 'text' })

D db.products.createIndex({ title: text(), description: text() })

💡 Hint

Remember that the index type is specified as a string.

The correct syntax uses strings to specify the index type, like "text". Omitting quotes or using functions is invalid.

❓ optimization

advanced

Optimize text search for multiple languages

You want to create a text index on the comments field of a collection reviews that supports English and Spanish languages for better search relevance. Which command achieves this?

A db.reviews.createIndex({ comments: "text" }, { default_language: "spanish" })

B db.reviews.createIndex({ comments: "text" }, { weights: { comments: 1 }, default_language: "spanish" })

C db.reviews.createIndex({ comments: "text" }, { language_override: "spanish" })

D db.reviews.createIndex({ comments: "text" }, { default_language: "english" })

💡 Hint

MongoDB text indexes support one default language per index for stemming and stop words.

MongoDB text indexes allow specifying one default_language for stemming and stop words. To support multiple languages, you typically create separate fields or indexes or handle language detection in your app.

🔧 Debug

advanced

Why does this text search query return no results?

You created a text index on the summary field of the books collection. You run this query but get no results: db.books.find({ $text: { $search: "adventure" } }). What is the most likely reason?

A The <code>$search</code> operator requires exact phrase matching with quotes.

B The text index was created on a different field, not on <code>summary</code>.

C The collection has no documents with the word 'adventure' in the <code>summary</code> field.

D Text search queries require specifying the language in the query.

💡 Hint

Check which fields have the text index.

If the text index is not on the field you are searching, the query will not find matches. The $text operator only searches fields included in the text index.

🧠 Conceptual

expert

Understanding text score sorting in MongoDB

You run this query on a collection posts with a text index on content:
db.posts.find({ $text: { $search: "database" } }, { score: { $meta: "textScore" } }).sort({ score: { $meta: "textScore" } })
What does the score field represent in the output documents?

A The timestamp when the document was last updated.

B The number of times the word 'database' appears in the content field.

C A numeric value representing how well the document matches the search terms; higher means better match.

D The length of the content field in characters.

💡 Hint

Text score is a relevance measure computed by MongoDB.

The textScore is a relevance score MongoDB assigns to each document based on how well it matches the search terms. Higher scores mean better matches.