An anonymous reader quotes a report from Ars Technica: In its continued efforts to make Azure a platform that appeals to the widest range of developers possible, Microsoft announced a range of new features at Build, its annual developer conference. Many of the features shown today had a data theme to them. The most novel feature was the release of Cosmos DB, a replacement for, or upgrade to, Microsoft's Document DB NoSQL database. Cosmos DB is designed for "planet-scale" applications, giving developers fine control over the replication policies and reliability. Replicated, distributed systems offer trade-offs between latency and consistency; systems with strong consistency wait until data is fully replicated before a write is deemed to be complete, which offers consistency at the expense of latency. Systems with eventual consistency mark operations as complete before data is fully replicated, promising only that the full replication will occur eventually. This improves latency but risks delivering stale data to applications. Document DB offered four different options for the replication behavior; Cosmos DB ups that to five. The database scales to span multiple regions, with Microsoft offering service level agreements (SLAs) for uptime, performance, latency, and consistency. There are financial penalties if Microsoft misses the SLA requirements. Many applications still call for traditional relational databases. For those, Microsoft is adding both a MySQL and a PostgreSQL service; these provide the familiar open source databases in a platform-as-a-service style, removing the administrative overhead that comes of using them and making it easier to move workloads using them into Azure. The company is also offering a preview of a database-migration service that takes data from on-premises SQL Server and Oracle databases and migrates it to Azure SQL Database. Azure SQL Database has a new feature in preview called "Managed Instances" that offers greater compatibility between on-premises SQL Server and the cloud variant, again to make workload migration easier.