Research & Evidence-Based Practice Flashcards

Which Azure Cosmos DB consistency level provides the strongest consistency guarantee, ensuring reads always return the most recently committed write?

Answer: Strong

Strong consistency guarantees linearizability, so every read reflects the latest committed write across all replicas.

What is the purpose of a lease on an Azure Blob Storage blob?

Answer: To provide an exclusive lock for write and delete operations

Acquiring a lease grants an exclusive lock on a blob, preventing other clients from writing or deleting it until the lease is released.

Which Azure Blob Storage access tier has the highest per-GB storage cost but the lowest per-operation access cost?

Answer: Hot

The Hot tier is optimized for frequently accessed data with higher storage costs offset by low per-read costs.

In Azure Cosmos DB, what property determines how data is distributed across logical and physical partitions?

Answer: The partition key

Cosmos DB hashes the partition key value to route each document to a specific logical partition for even data distribution.

Which HTTP status code does Azure Blob Storage return when an If-Match ETag condition fails during a conditional request?

Answer: 412 Precondition Failed

412 Precondition Failed is returned when the blob's current ETag does not match the value specified in If-Match, indicating a concurrent modification.

Which Azure Cosmos DB API is the best choice for migrating an existing MongoDB application with minimal code changes?

Answer: API for MongoDB

The Azure Cosmos DB for MongoDB API offers wire-protocol compatibility with MongoDB drivers, so existing applications work with minimal modification.

What is the maximum size of a single item (document) stored in Azure Cosmos DB, regardless of API?

Answer: 2 MB

Azure Cosmos DB enforces a 2 MB size limit per item across all supported APIs.