Cosmos DB overview and use cases in Azure - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Cosmos DB Consistency Levels

Which Cosmos DB consistency level guarantees the highest data consistency but may impact latency and availability?

A Strong consistency

B Bounded staleness consistency

C Session consistency

D Eventual consistency

💡 Hint

Think about the trade-off between consistency and latency in distributed databases.

Strong consistency ensures that reads always return the most recent committed write, providing the highest data consistency. However, it can increase latency and reduce availability in distributed systems.

❓ Architecture

intermediate

Choosing Cosmos DB API for a Use Case

You need to build a globally distributed application that stores JSON documents and requires rich querying capabilities. Which Cosmos DB API should you choose?

A SQL (Core) API

B Cassandra API

C Gremlin API

D Table API

💡 Hint

Consider which API is optimized for JSON document storage and querying.

The SQL (Core) API is designed for JSON document storage and supports rich SQL-like queries, making it ideal for document-based applications.

❓ service_behavior

advanced

Impact of Partition Key Choice on Cosmos DB Performance

What is the most likely impact of choosing a partition key with low cardinality in Cosmos DB?

A Automatic scaling of storage without performance impact

B Hot partition causing throttling and reduced performance

C Improved write throughput due to even data distribution

D Increased consistency across regions

💡 Hint

Think about how data distribution affects load balancing in Cosmos DB.

A partition key with low cardinality causes many requests to target the same partition, creating a hot partition that leads to throttling and reduced performance.

❓ security

advanced

Securing Access to Cosmos DB Data

Which method provides the most secure way to grant an application read-only access to a Cosmos DB container without exposing the master key?

A Use the master key directly in the application code

B Enable IP firewall rules only

C Use the primary key with read permissions

D Create a read-only resource token scoped to the container

💡 Hint

Consider least privilege and key exposure risks.

Resource tokens provide scoped, time-limited access to specific resources without exposing the master key, following the principle of least privilege.

✅ Best Practice

expert

Optimizing Cosmos DB for Global Distribution and Latency

You have a Cosmos DB account replicated in multiple regions worldwide. To minimize read latency for users globally, which configuration should you enable?

A Enable multi-master write regions with single write region

B Use strong consistency across all regions

C Configure preferred regions for read requests in the SDK

D Disable automatic failover

💡 Hint

Think about how the SDK can direct read requests to the nearest region.

Configuring preferred regions in the Cosmos DB SDK directs read requests to the nearest region, reducing latency for global users.