Master MongoDB Basics: Essential Questions for Interviews
Prepare for your MongoDB interview with these 10 essential questions covering core concepts, commands, and features. Strengthen your understanding of NoSQL basics with supported explanations for each answer!
Question 1.
What is MongoDB?
A.
A relational database management system
B.
A NoSQL database designed for scalability and flexibility
C.
A programming language
D.
A caching tool
Your Response:
-
Explanation: MongoDB is a NoSQL database that stores data in JSON-like documents, making it highly scalable and flexible for modern application development
Question 2.
How does MongoDB store data?
A.
Tables and rows
B.
XML files
C.
Key-value pairs
D.
Documents and collections
Your Response:
-
Explanation: MongoDB stores data as documents in collections, where documents are analogous to rows in relational databases and collections are similar to tables.
Question 3.
Which data format does MongoDB use to store documents?
A.
JSON
B.
BSON
C.
XML
D.
YAML
Your Response:
-
Explanation: MongoDB stores data in Binary JSON (BSON) format, which extends JSON and supports additional data types such as Date and Binary.
Question 4.
What is the default port for MongoDB?
A.
27015
B.
3306
C.
27017
D.
8080
Your Response:
-
Explanation: MongoDB’s default port is 27017, which is used for client connections.
Question 5.
How do you insert a document into a MongoDB collection?
A.
db.collection.push()
B.
db.collection.insert()
C.
db.collection.add()
D.
db.collection.save()
Your Response:
-
Explanation: The insert() method is used to add one or more documents to a MongoDB collection.
Question 6.
Which command is used to find documents in a collection?
A.
db.collection.find()
B.
db.collection.search()
C.
db.collection.get()
D.
db.collection.fetch()
Your Response:
-
Explanation: The find() method retrieves documents that match a query from a MongoDB collection.
Question 7.
What is the purpose of an index in MongoDB?
A.
To compress data
B.
To speed up read operations
C.
To restrict document access
D.
To enforce schema
Your Response:
-
Explanation: Indexes improve the performance of search queries by allowing MongoDB to quickly locate documents that match a query filter.
Question 8.
Which of the following is not a valid MongoDB data type?
A.
String
B.
Integer
C.
Array
D.
Float
Your Response:
-
Explanation: MongoDB does not have a Float data type. It uses Double for floating-point numbers.
Question 9.
What does the aggregation framework in MongoDB do?
A.
Deletes documents in bulk
B.
Performs advanced data processing and transformation
C.
Updates multiple documents
D.
Creates indexes
Your Response:
-
Explanation: The aggregation framework is used to process data, perform computations, and transform results, similar to SQL's GROUP BY.
Question 10.
How does MongoDB handle relationships between data?
A.
Using Foreign Keys
B.
Using Joins like SQL
C.
Using Embedded Documents and References
D.
Using Temporary Tables
Your Response:
-
Explanation: MongoDB uses embedded documents for denormalized data and references for normalized data to handle relationships, unlike SQL databases that rely on joins and foreign keys.