MongoDB - Quiz | Analytics

Q: When were locks implemented at the database level in MongoDB?

A. Before version 2.2
B. With version 2.2
C. Since version 3.0
D. None of the above

Correct Option: B
Explanation:

Answer: With version 2.2 Explanation: Before version 2.2, locks were implemented on a per-server process basis. With version 2.2, locks were implemented at the database level.

Q: What is MongoDB's role in the MACH Alliance?

A. Founding member
B. Supporting member
C. Honorary member
D. Advisory board member

Correct Option: B
Explanation:

Answer: Supporting member Explanation: MongoDB is a supporting member of the MACH Alliance.

Q: Find the command that removes the user from the current database.

A. db.dropUser()
B. db.dropsUsers()
C. db.getUsers()
D. All the Options

Correct Option: A
Explanation: db.dropUser()

Q: Which of the following is a valid MongoDB projection operator?

A. $
B. $
C. #
D. @

Correct Option: A
Explanation:

Answer: $ Explanation: MongoDB projection operators start with the $ sign, such as $project, $slice, $elemMatch, and more.

Q: What issue did Jepsen find with MongoDB 3.6.4?

A. Unauthorized access to database
B. Denial of service attacks
C. Retrocausal transactions
D. SQL injection attacks

Correct Option: C
Explanation:

Answer: Retrocausal transactions Explanation: Jepsen found that MongoDB 3.6.4 had issues with retrocausal transactions, where a transaction reverses order so that a read can see the result of a future write.

Q: What is a MongoDB replica set?

A. A set of related collections
B. A set of related databases
C. A set of related documents
D. A set of related servers

Correct Option: D
Explanation:

Answer: A set of related servers Explanation: A MongoDB replica set is a group of MongoDB servers that maintain the same data set and provide redundancy and high availability.

Q: When was MongoDB initially released?

A. 2005
B. 2007
C. 2009
D. 2011

Correct Option: C
Explanation:

Answer: 2009 Explanation: MongoDB was initially released on February 11, 2009.

Q: What security measure did MongoDB implement in its 2.6 release onwards?

A. Bind all networked connections to the database by default
B. Allow anyone to have full access to the database
C. Allow ransomware attacks to hold MongoDB servers hostage
D. None of the above

Correct Option: A
Explanation:

Answer: Bind all networked connections to the database by default Explanation: From the MongoDB 2.6 release onwards, the binaries from the official MongoDB RPM and DEB packages bind to localhost by default. From MongoDB 3.6, this default behavior was extended to all MongoDB packages across all platforms. As a result, all networked connections to the database will be denied unless explicitly configured by an administrator.

Q: What language is MongoDB not written in?

A. Java
B. C++
C. Python
D. Ruby

Correct Option: D
Explanation:

Answer: Ruby Explanation: MongoDB is written in C++, JavaScript, and Python. Not written in Ruby.

Q: What type of locks were implemented on a per-server process basis before MongoDB version 2.2?

A. Collection level locks
B. Database level locks
C. No locks were implemented
D. All of the above

Correct Option: A
Explanation:

Answer: Collection level locks Explanation: Before version 2.2, locks were implemented on a per-server process basis, and with version 2.2, locks were implemented at the database level.