Microsoft Certified: Azure Solutions Architect ExpertDesign infrastructure solutionsMedium
A global e-commerce company is designing a new platform that requires a highly available and globally distributed database. The database must support multiple write regions, automatic failover, and provide single-digit millisecond latency for reads and writes to users worldwide. Which Azure database service should you recommend?
- AAzure SQL Database
- BAzure Database for PostgreSQL
- CAzure Cosmos DB
- DAzure Cache for Redis
Show answer & explanationAnswer & explanation
Correct answer: C. Azure Cosmos DB
Azure Cosmos DB is a globally distributed, multi-model database service that offers turn-key global distribution with multi-region writes, automatic failover, and guarantees single-digit millisecond latency at the 99th percentile anywhere in the world. This perfectly matches the requirements for a high-performance, globally distributed e-commerce platform.
Why the other options are wrong
- A. Azure SQL Database can be geo-replicated for high availability, but typically supports only one write region and does not inherently provide the global multi-region write and single-digit millisecond latency guarantees of Cosmos DB.
- B. Azure Database for PostgreSQL (and other Azure relational databases) supports read replicas and geo-redundancy, but not built-in multi-region writes with guaranteed low latency globally.
- D. Azure Cache for Redis is an in-memory data store for caching, not a primary, persistent database solution for an entire e-commerce platform.
Azure Cosmos DB
A fully managed, globally distributed, multi-model database service for mission-critical applications.
- Turn-key global distribution with multi-region writes.
- Guaranteed single-digit millisecond latency at 99th percentile.
- Multiple APIs (SQL, MongoDB, Cassandra, Gremlin, Table).
Memory trick: Cosmos DB: It's a 'Cosmos' of data, everywhere, instantly.