Built-in roles (read, readWrite, dbAdmin) in MongoDB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

What does the read role allow a user to do?

In MongoDB, the read built-in role grants specific permissions. Which of the following best describes what a user with the read role can do?

A Read data from all collections in the database but cannot modify any data.

B Read and write data to all collections in the database.

C Manage users and roles for the database.

D Read data and create indexes but cannot write or modify data.

💡 Hint

Think about what 'read' means in terms of data access.

The read role allows users to read data from all collections but does not allow any write or administrative actions.

❓ query_result

intermediate

What operations can a user with the readWrite role perform?

A user is assigned the readWrite role on a MongoDB database. Which of the following actions can this user perform?

A Only read data from collections.

B Manage database users and roles.

C Read and write data, including inserting, updating, and deleting documents.

D Only create indexes but cannot modify data.

💡 Hint

Consider what 'write' implies in addition to 'read'.

The readWrite role allows users to read and modify data, including inserting, updating, and deleting documents.

❓ query_result

advanced

Which actions are allowed by the dbAdmin role in MongoDB?

The dbAdmin role provides administrative privileges on a database. Which of the following actions can a user with this role perform?

A Read and write data in collections.

B Only read data from collections.

C Manage users and roles across all databases.

D Create and drop collections, manage indexes, and view statistics but cannot read or write data.

💡 Hint

Think about administrative tasks that do not involve data modification.

The dbAdmin role allows users to perform administrative tasks like creating or dropping collections and managing indexes but does not grant read or write data permissions.

📝 Syntax

advanced

Which command correctly grants the readWrite role to a user on the sales database?

You want to grant the readWrite role to user alice on the sales database. Which of the following MongoDB shell commands is correct?

A db.grantRolesToUser('alice', [{ role: 'readWrite', db: 'sales' }])

B db.updateUser('alice', { roles: ['readWrite'] })

C db.updateUser('alice', { roles: [{ role: 'readWrite', db: 'sales' }] })

D db.grantRolesToUser('alice', ['readWrite'])

💡 Hint

Check the correct method and format for updating user roles.

The grantRolesToUser method is used to add roles to a user without overwriting existing roles, and roles must be specified as an array of role objects with role and db fields.

🧠 Conceptual

expert

Why should you avoid assigning the dbAdmin role to users who only need to read and write data?

Consider the security and best practices in MongoDB role assignments. Why is it not recommended to assign the dbAdmin role to users who only need to read and write data?

A Because <code>dbAdmin</code> does not allow reading or writing data, so users cannot perform their tasks.

B Because <code>dbAdmin</code> allows managing collections and indexes, which can affect database structure and performance, posing unnecessary risks.

C Because <code>dbAdmin</code> automatically grants access to all databases, which is a security risk.

D Because <code>dbAdmin</code> role expires after 24 hours, causing access issues.

💡 Hint

Think about the principle of least privilege.

Assigning dbAdmin to users who only need data access grants them unnecessary administrative powers that could unintentionally affect database structure or performance.