MongoDB is a powerful and widely-used NoSQL database that enables developers to manage unstructured and semi-structured data efficiently. It offers flexibility, scalability, and performance, making it a popular choice for modern web applications, big data projects, and real-time analytics. To strengthen your MongoDB skills, practicing MongoDB MCQ Questions is an effective way to test your knowledge and prepare for interviews, certifications, or project implementation.
This quiz contains a diverse set of MongoDB MCQ Questions covering topics from basic concepts like CRUD operations, indexing, and data modeling to advanced features like replication, sharding, and query optimization. These questions are designed to cater to learners of all levels—whether you’re a beginner trying to understand MongoDB’s core concepts or an expert looking to validate your expertise.
MongoDB MCQs not only reinforce theoretical knowledge but also help you gain practical insights into database operations and best practices. Whether you’re preparing for a certification exam like MongoDB Developer Associate or simply brushing up your skills for a job interview, these MCQs will provide a comprehensive review of key topics.
Let’s explore the MongoDB world through these multiple-choice questions and level up your expertise!
30 Sample MongoDB MCQs with Answers
- What does BSON stand for?
- a) Binary System Object Notation
- b) Binary Script Object Notation
- c) Binary JSON
- d) Binary Serialized Object Notation
- Answer: c) Binary JSON
- Which MongoDB command creates a database?
- a)
CREATE DATABASE db_name - b)
use db_name - c)
db.createDatabase() - d)
db.create() - Answer: b)
use db_name
- a)
- What type of NoSQL database is MongoDB?
- a) Key-Value Store
- b) Document-Oriented
- c) Columnar Store
- d) Graph Database
- Answer: b) Document-Oriented
- What is the default port for MongoDB?
- a) 8080
- b) 27017
- c) 3306
- d) 1521
- Answer: b) 27017
- Which MongoDB operator is used for equality in queries?
- a)
$match - b)
$equal - c)
$eq - d)
$equals - Answer: c)
$eq
- a)
- How is data stored in MongoDB?
- a) Tables
- b) Collections
- c) Rows
- d) Columns
- Answer: b) Collections
- What does the
db.stats()command provide?- a) Collection statistics
- b) Server uptime
- c) Database statistics
- d) Index details
- Answer: c) Database statistics
- Which method retrieves all documents in a collection?
- a)
db.collection.all() - b)
db.collection.findAll() - c)
db.collection.find() - d)
db.collection.get() - Answer: c)
db.collection.find()
- a)
- What is the purpose of a replica set in MongoDB?
- a) Backup
- b) High Availability
- c) Load Balancing
- d) Data Partitioning
- Answer: b) High Availability
- Which aggregation stage is used to group documents?
- a)
$sort - b)
$group - c)
$aggregate - d)
$match - Answer: b)
$group
- a)
- Which command removes a collection?
- a)
db.collection.remove() - b)
db.collection.drop() - c)
db.dropCollection() - d)
drop.collection() - Answer: b)
db.collection.drop()
- a)
- What is a shard key?
- a) A key to encrypt data
- b) A unique index key
- c) A field to distribute data across shards
- d) A key for full-text search
- Answer: c) A field to distribute data across shards
- Which of these is a valid MongoDB datatype?
- a) Integer
- b) Array
- c) ObjectId
- d) All of the above
- Answer: d) All of the above
- How do you add a field to an existing document?
- a)
$add - b)
$set - c)
$update - d)
$modify - Answer: b)
$set
- a)
- Which storage engine is the default in MongoDB?
- a) WiredTiger
- b) InnoDB
- c) RocksDB
- d) LevelDB
- Answer: a) WiredTiger
- What is the function of the
$unwindstage?- a) Combine multiple documents
- b) Split an array into multiple documents
- c) Filter documents
- d) Sort documents
- Answer: b) Split an array into multiple documents
- What is the maximum BSON document size?
- a) 4 MB
- b) 8 MB
- c) 16 MB
- d) 32 MB
- Answer: c) 16 MB
- Which of these is used for database backups in MongoDB?
- a)
mongodump - b)
mongoimport - c)
mongos - d)
mongosh - Answer: a)
mongodump
- a)
- Which MongoDB method creates an index?
- a)
db.collection.addIndex() - b)
db.collection.ensureIndex() - c)
db.collection.createIndex() - d)
db.collection.index() - Answer: c)
db.collection.createIndex()
- a)
- Which MongoDB operator is used for text search?
- a)
$text - b)
$find - c)
$search - d)
$regex - Answer: a)
$text
- a)
- What is MongoDB Compass?
- a) A command-line interface
- b) A graphical user interface for MongoDB
- c) A backup tool
- d) A query language
- Answer: b) A graphical user interface for MongoDB
- What does
mongosdo in a sharded cluster?- a) Provides shard management
- b) Acts as a query router
- c) Handles replication
- d) Performs backups
- Answer: b) Acts as a query router
- What is the purpose of
$mergein aggregation?- a) Combine collections
- b) Write aggregation results to a collection
- c) Merge indexes
- d) Join collections
- Answer: b) Write aggregation results to a collection
- Which command is used to list databases?
- a)
show collections - b)
show dbs - c)
db.show() - d)
list dbs - Answer: b)
show dbs
- a)
- What does
rs.initiate()do?- a) Initializes a sharded cluster
- b) Starts replication in a replica set
- c) Creates an index
- d) Configures sharding
- Answer: b) Starts replication in a replica set
- What does
db.collection.stats()provide?- a) Shard statistics
- b) Index usage
- c) Collection details
- d) Query performance
- Answer: c) Collection details
- What does the
$limitstage do?- a) Restrict fields in the output
- b) Limit the number of documents in output
- c) Limit the size of the database
- d) Restrict aggregation stages
- Answer: b) Limit the number of documents in output
- Which MongoDB shell is interactive and modern?
- a)
mongos - b)
mongosh - c)
mongo-cli - d)
mongo-exec - Answer: b)
mongosh
- a)
- Which aggregation operator is used for arithmetic calculations?
- a)
$calc - b)
$add - c)
$math - d)
$operation - Answer: b)
$add
- a)
- What is the function of
$outin aggregation?- a) Print output to console
- b) Write aggregation results to a new collection
- c) Export data to a file
- d) Create a new document
- Answer: b) Write aggregation results to a new collection