Ultimate Mongodb Test - 78+ MCQs: MongoDB test: Assess Your Knowledge with MongoDB Questions and Answers

1. What is the default port for MongoDB?

27017

3306

8080

5432

2. What is the purpose of the $graphLookup stage in MongoDB aggregation?

Data modeling

Recursive queries

Data validation

Query optimization

3. What is the purpose of the `ttl` index type in MongoDB?

To store timestamps

To perform text search

To create a time-to-live index

To encrypt data

4. What is the purpose of the $push operator in MongoDB?

Array modification

Document deletion

Data encryption

Query optimization

5. What is the purpose of the `$redact` stage in MongoDB aggregation?

To apply conditional transformations

To project specific fields

To restrict access to sensitive data

To perform regular expression matching

6. In MongoDB, what is the primary role of the `mongos` process?

Client application for MongoDB

MongoDB database server

Query optimizer

Shard router in a sharded cluster

7. How does MongoDB handle transactions, and what types of operations support transactions?

Concurrency control

Data validation

Data modeling

Atomic operations

8. Explain the difference between find() and findOne() methods in MongoDB.

Data aggregation

Data retrieval

Indexing strategy

Data validation

9. What is the purpose of the `explain()` method in MongoDB?

To provide documentation for queries

To analyze and report on the query execution plan

To debug MongoDB server issues

To format query results

10. Which operator is used for equality in MongoDB queries?

$eq

$equals

$eqs

$equal

11. What is the purpose of the TTL (Time To Live) index in MongoDB?

Document versioning

Automatic data expiration

Query optimization

Geospatial indexing

12. How can you perform a case-sensitive search in MongoDB?

$regex: /pattern/i

$caseSensitive: true

$matchCase: true

$cs: /pattern/

13. In MongoDB, how do you create a compound index?

db.createIndex({ field1: 1, field2: 1 })

db.index({ field1: 'asc', field2: 'desc' })

db.ensureIndex({ field1: 'ascending', field2: 'descending' })

db.field1.field2.createIndex()

14. Which aggregation stage is used to group documents by multiple fields?

$match

$group

$project

$sort

15. What is the role of the WiredTiger storage engine in MongoDB?

Data encryption

Query optimization

Journaling

Storage and retrieval of data

16. In MongoDB, what is a capped collection?

A collection with a maximum size

A collection with predefined documents

A collection with nested documents

A collection with unlimited storage

17. What is the primary purpose of MongoDB?

Relational Database Management

Document-Oriented Database Management

Graph Database Management

Key-Value Pair Database Management

18. What is the `$all` operator used for in MongoDB?

Matches arrays with a specific element

Matches arrays with all specified elements

Negates the results of an aggregation stage

Selects documents with a not-in condition

19. What is a sharded cluster in MongoDB, and why might it be used?

Replication mechanism

Distributed database

Security layer

Indexing strategy

20. What does the term 'BSON' stand for in MongoDB?

Binary Structured Object Notation

Basic Structured Object Notation

Boolean Structured Object Notation

Binary System Object Notation

21. How can you perform a multi-field sort in MongoDB?

db.sort()

db.orderBy()

db.sortBy()

db.find().sort()

22. Explain the significance of the ObjectId in MongoDB documents.

Primary key

Timestamp

Foreign key

Random identifier

23. In MongoDB, what is the purpose of the `explain()` method?

To provide documentation for queries

To analyze and report on the query execution plan

To debug MongoDB server issues

To format query results

24. Explain the concept of MongoDB change streams and their use cases.

Data transformation

Real-time data updates

Data validation

Data modeling

25. How can you limit the number of documents returned in a MongoDB query?

db.limit()

db.count()

db.find().limit()

db.max()

26. In MongoDB, what is a covered query?

Query with multiple conditions

Query without an index

Query using aggregation

Query where all fields are in the index

27. Explain the concept of document-level locking in MongoDB.

Concurrency control

Data validation

Data modeling

Query optimization

28. What is the purpose of the $redact stage in MongoDB aggregation?

Data transformation

Data security

Data validation

Query optimization

29. What is the role of an index in MongoDB, and how does it impact query performance?

Data encryption

Data compression

Data validation

Query optimization

30. In MongoDB, what is a replica set?

A set of related tables

A group of database servers

A collection of documents

A cluster of indexes

MongoDB MCQ Test 3