How is Microsoft SDS related to a traditional on-premise relational SQL Server database?
SDS is built on SQL Server database technologies, used for running mission-critical applications in the enterprise as well as on the Web. Since SQL Server is a broad data platform that can handle all data from birth to archival, there are many capabilities that our data platform provides. SDS is exposing a subset of those capabilities and extending them as services in the cloud in ways that make it easy for customers and partners to consume and build upon over the Internet. Although SDS in its first iteration exposes only a small subset of what is in the full SQL Server data platform, Microsoft expects this to increase over time, with likely features including aggregates, distributed queries, schemas, Reporting, Analytics, ETL.