Microsoft Azure Fundamentals (AZ-900)Describe Azure architecture and servicesHard
A financial institution requires a database solution for its new online banking application. This application needs extremely low-latency data access globally, automatic scaling for both throughput and storage, and support for multiple data models (key-value, document, graph). Which Azure database service is the most appropriate choice?
- AAzure Cosmos DB
- BAzure Cache for Redis
- CAzure SQL Database
- DAzure Database for PostgreSQL
Show answer & explanationAnswer & explanation
Correct answer: A. Azure Cosmos DB
Azure Cosmos DB is a fully managed NoSQL database service for modern app development. It offers guaranteed single-digit millisecond latencies, automatic and instant scalability, and support for multiple APIs including document, key-value, graph, and column-family data models, making it ideal for global, high-performance applications.
Why the other options are wrong
- B. Azure Cache for Redis is an in-memory data store for caching, not a primary database service for persistent storage and multiple data models.
- C. Azure SQL Database is a relational database, not designed for multiple data models or global low-latency NoSQL needs.
- D. Azure Database for PostgreSQL is a relational database, similar to SQL DB, and does not fit the multi-model or global NoSQL requirements.
Azure Cosmos DB
Azure Cosmos DB is a globally distributed, multi-model database service that offers high availability, guaranteed low latency, and automatic scalability.
- Supports multiple data models (e.g., document, key-value, graph).
- Guaranteed single-digit millisecond latency at the 99th percentile.
- Elastic scalability for throughput and storage.
Memory trick: Cosmos DB is the 'Swiss Army Knife' of databases: global, fast, and handles every data shape.