MCQs on Advanced Query and Index Optimization | MongoDB MCQs
MongoDB offers powerful features for advanced query and index optimization, enhancing database performance. Developers can utilize geospatial queries for location-based data, full-text search for fast text retrieval, TTL indexes for automated data expiration, and performance tuning techniques for scalability. This quiz explores these advanced concepts to boost your MongoDB expertise.
Geospatial Queries
Q1. What type of index is required to perform geospatial queries in MongoDB?
a) Compound Index
b) Geospatial Index
c) Text Index
d) TTL Index
Q2. Which operator is used to find documents within a specific geometry?
a) $within
b) $geoWithin
c) $contains
d) $geoMatch
Q3. The $near operator in geospatial queries is used to:
a) Match documents by exact coordinates
b) Sort documents by distance from a point
c) Check if a field exists
d) Perform full-text search
Q4. In MongoDB, geospatial data is represented using:
a) Arrays of points
b) JSON strings
c) Binary objects
d) Tables
Q5. Which of the following is NOT a valid geospatial index type in MongoDB?
a) 2d Index
b) 2dsphere Index
c) Polygon Index
d) None of the above
Full-Text Search Queries
Q6. What type of index is required for full-text search in MongoDB?
a) Compound Index
b) Full-text Index
c) Text Index
d) Unique Index
Q7. Which command is used to perform a full-text search in MongoDB?
a) db.collection.textSearch()
b) db.collection.search()
c) $text
d) $findText
Q8. In a full-text search query, the $text operator requires which field to be included?
a) $search
b) $index
c) $match
d) $contains
Q9. What does the $language field specify in a text search query?
a) The text encoding format
b) The natural language for stemming and tokenization
c) The character limit for the text
d) The index size
Q10. How do you assign a custom score to search results in MongoDB text search?
a) Using $sort
b) Using $meta
c) Using $rank
d) Using $priority
TTL (Time-to-Live) Indexes
Q11. What is the primary use of TTL indexes in MongoDB?
a) Archiving documents
b) Automatically deleting expired documents
c) Improving query performance
d) Optimizing storage
Q12. TTL indexes are set on which type of field?
a) Numeric fields
b) String fields
c) Date fields
d) ObjectId fields
Q13. What is the minimum granularity of TTL expiration in MongoDB?
a) 1 second
b) 1 millisecond
c) 1 minute
d) 1 hour
Q14. How is the expiration time defined for a document in a TTL index?
a) By the _id field
b) Using a specific TTL field
c) Through a Unix timestamp field
d) Using the index creation command
Q15. What happens when the expiration time of a TTL-indexed document is reached?
a) The document is archived
b) The document is deleted automatically
c) An error is thrown
d) The index is dropped
Performance Tuning Techniques
Q16. What is the purpose of using explain() in MongoDB?
a) To execute a query faster
b) To analyze query performance and execution plan
c) To create indexes
d) To delete unnecessary data
Q17. Which parameter can be used to limit memory usage for MongoDB queries?
a) queryOptimizer
b) allowDiskUse
c) memoryLimit
d) maxQueryMem
Q18. How does sharding improve MongoDB performance?
a) By reducing the document size
b) By distributing data across multiple nodes
c) By compressing indexes
d) By archiving old data
Q19. What is the impact of using compound indexes?
a) Improves query performance for specific use cases
b) Reduces storage requirements
c) Slows down write operations
d) Prevents duplicate entries
Q20. Which of the following can improve write performance in MongoDB?
a) Increasing index size
b) Using smaller document sizes
c) Reducing memory usage
d) Limiting the number of shards
Q21. How can you monitor database performance in MongoDB?
a) Using db.performanceCheck()
b) Through MongoDB Compass or Monitoring Tools
c) By writing custom scripts
d) Through server logs
Q22. Which option ensures atomic operations in MongoDB?
a) Using transactions
b) Using queries
c) By creating unique indexes
d) By sharding collections
Q23. What does the WiredTiger engine optimize in MongoDB?
a) CPU performance
b) Disk I/O and concurrency
c) Memory usage
d) Backup speeds
Q24. Which tool can analyze MongoDB logs for query performance?
a) mongo-analyze
b) profiler
c) mongotop
d) logParser
Q25. Which is NOT a recommended strategy for performance tuning in MongoDB?
a) Reducing index usage
b) Indexing frequently queried fields
c) Analyzing slow queries
d) Using sharding for large datasets
Answer Key
| QNo | Answer |
|---|---|
| 1 | b) Geospatial Index |
| 2 | b) $geoWithin |
| 3 | b) Sort documents by distance from a point |
| 4 | a) Arrays of points |
| 5 | c) Polygon Index |
| 6 | c) Text Index |
| 7 | c) $text |
| 8 | a) $search |
| 9 | b) The natural language for stemming and tokenization |
| 10 | b) Using $meta |
| 11 | b) Automatically deleting expired documents |
| 12 | c) Date fields |
| 13 | c) 1 minute |
| 14 | c) Through a Unix timestamp field |
| 15 | b) The document is deleted automatically |
| 16 | b) To analyze query performance and execution plan |
| 17 | b) allowDiskUse |
| 18 | b) By distributing data across multiple nodes |
| 19 | a) Improves query performance for specific use cases |
| 20 | b) Using smaller document sizes |
| 21 | b) Through MongoDB Compass or Monitoring Tools |
| 22 | a) Using transactions |
| 23 | b) Disk I/O and concurrency |
| 24 | c) mongotop |
| 25 | a) Reducing index usage |
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