What is Managed Databases — Azure SQL & Cosmos DB in Microsoft Azure?

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Microsoft Azure

Managed Databases — Azure SQL & Cosmos DB

Choose managed relational (Azure SQL) or globally-distributed NoSQL (Cosmos DB).

Azure SQL Database is a fully managed relational database built on the SQL Server engine, with automated patching, backups, and high availability. It comes in deployment options — Single Database, Elastic Pools (share resources across many databases), and Managed Instance (near-full SQL Server compatibility for lift-and-shift). It scales with vCore or DTU models and offers built-in HA with zone-redundant configurations and active geo-replication for disaster recovery.

Azure SQL is a managed branch of a familiar bank that still follows all the classic rules (SQL, transactions). Cosmos DB is a global courier network with depots in every city: data is everywhere at once with millisecond pickup, and you dial exactly how synchronised the depots must be versus how fast they respond.

Key Concepts

Azure Cosmos DB is a globally distributed, multi-model NoSQL database offering single-digit-millisecond latency and turnkey multi-region replication, including multi-region writes (active-active). It supports several APIs (NoSQL/Core, MongoDB, Cassandra, Gremlin, Table) so existing apps can connect with familiar drivers, and is unique in offering five tunable consistency levels (strong, bounded staleness, session, consistent prefix, eventual), letting you trade consistency for latency and availability precisely. You partition by a partition key and provision throughput as RU/s (or use autoscale/serverless).