MongoDB Quiz (Scenario-Based) | Test Real Skills + Certificate

🔥 MongoDB Advanced Quiz (Scenario-Based) – Test Your Real Skills

Can you solve real-world MongoDB problems? 🤔

This advanced scenario-based quiz will test your skills in indexing, performance optimization, schema design, and aggregation.

🎯 Score 80%+ to prove you're job-ready.

📘 Recommended before attempting:

• MongoDB Security Best Practices
• MongoDB CRUD Practice
• Aggregation Practice

Test your MongoDB skills with real-world scenarios. Choose the best answer.

⏱ Time Left: 300 seconds

Q1. You have a user with thousands of orders. What is the best approach?

Embed all orders
Use separate orders collection
Store in one field

Q2. Your collection has 10M users. Query by email is slow despite index. Why?

Query uses regex without prefix
Need aggregation
Need sharding

Q3. You need to calculate total sales. Which is best?

Use aggregation $sum
Use find()
Use update()

Q4. You filter by category and sort by price. Which index is optimal?

{category:1, price:1}
{price:1, category:1}
Single index

Q5. Documents are exceeding size limit. What should you do?

Use referencing
Increase size manually
Ignore error

Q6. You want latest 5 records. Which query is best?

sort + limit
find only
deleteMany

Q7. You want to analyze query performance. What should you use?

explain()
debug()
log()

Q8. You need flexible schema. Why MongoDB?

Schema-less design
Fixed schema
No storage

Q9. You want to insert multiple documents at once. Which method is best?

insertMany()
insertOne()
save()

Q10. You want to retrieve only 5 records from a collection. What should you use?

limit()
skip()
sort()

Q11. You want to filter documents where age is greater than 25. Which operator is used?

$gt
$lt
$eq

Q12. You want flexible schema for storing data. Why MongoDB is useful?

Schema-less design
Fixed schema
No storage

Q13. Search by name is slow even with index. Why?

Low cardinality field
Too many documents
Aggregation needed

Q14. You want to search blog content by keywords. What should you use?

Text index
Normal index
limit()

Q15. Your database is growing rapidly across regions. What should you use?

Sharding
Indexing
Embedding

Q16. You notice duplicate records frequently. What should you implement?

Unique index
Aggregation
limit()

Q17. You need atomic updates across multiple fields. What should you use?

Transactions
find()
sort()

Q18. Aggregation pipeline is slow. What improves performance?

Use $match early
Use $group first
Remove indexes

Q19. You need to find nearby users. What should you use?

Geospatial index
Text index
Compound index

Q20. Your system must not go down. What is best setup?

Replica set
Single server
Indexing

Q21. Your app frequently queries users by country and status. What is the best index?

{country:1, status:1}
{status:1}
{country:1}

Q22. You need to store logs with varying fields across services. Best approach?

Use flexible schema documents
Use strict schema
Use SQL tables

Q23. You need to ensure email uniqueness in a collection. What should you use?

Unique index
Text index
Hashed index

Q24. A query filters on age but sorts on salary. Best index?

{age:1, salary:1}
{salary:1, age:1}
{age:1}

Q25. You want to expire session data automatically. What feature should you use?

TTL index
Sharding
Aggregation

Q26. Your aggregation is slow due to large dataset. First optimization step?

Add $match early
Add $group first
Remove indexes

Q27. You need to distribute write load evenly. Which index helps?

Hashed index
Text index
Compound index

Q28. You want to store hierarchical category data. Best design?

Parent reference pattern
Flat structure only
Use arrays for everything

Q29. Your query uses multiple OR conditions. What helps optimize?

Index each field used in OR
Use single index only
Avoid indexes

Q30. You want to reduce document size by excluding fields. Which operator?

Projection
Aggregation
Indexing

Q31. You need real-time analytics dashboard. Best approach?

Aggregation pipeline
find()
insertMany()

Q32. You want to shard data based on userId. Best shard key?

userId
random field
timestamp only

Q33. Your writes are slow due to journaling. What can you tune?

Write concern
Index only
Aggregation

Q34. You want to lookup data from another collection. Which stage?

$lookup
$match
$sort

Q35. You want to flatten nested arrays. Which operator?

$unwind
$group
$match

Q36. You want to cache frequent queries. Best approach?

Use Redis caching
Add more indexes
Use aggregation

Q37. You want partial indexing for active users only. What to use?

Partial index
Full index
Text index

Q38. You want to handle high read traffic globally. What helps?

Read replicas
Single node
Remove indexes

Q39. You need to track changes in documents. Best feature?

Change streams
Aggregation
Projection

Q40. You want to avoid scanning entire collection. What is critical?

Proper indexing
Larger documents
More collections

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📌 What You Learned

This MongoDB quiz tested your knowledge of:

• Schema design (embedding vs referencing)
• Indexing and query performance
• Aggregation framework
• Real-world database optimization

👉 Continue Learning:

• MongoDB CRUD Practice
• Aggregation Practice
• Indexing & Performance