Microsoft Azure Solutions Architect Expert AZ-305 Practice Question

Azure Cosmos DB configured with the Core (SQL) API is purpose-built for globally distributed, semi-structured datasets. A Cosmos DB account can span any number of Azure regions with optional multi-region write capability, guaranteeing single-digit millisecond read latency for 99th-percentile requests worldwide. Every document property is automatically indexed by default, and per-item TTL can be enabled to expire data after a specified period. These capabilities are provided as a fully managed PaaS offering, so no infrastructure maintenance is required.

Blob Storage with a CDN offers global read caching but cannot provide millisecond document reads, multi-master writes, or automatic document indexing. Azure SQL Database can store JSON in columns but lacks multi-region write support and does not automatically index arbitrary JSON properties. Azure Table Storage provides geo-replication for disaster recovery rather than active multi-region writes; it also lacks per-item TTL controls and automatic indexing of every attribute. Therefore, Cosmos DB is the only option that satisfies all listed requirements.