This document discusses SQL Azure, Microsoft's relational database service. It describes the logical and physical structure, including that databases are organized at the subscription and server level, and SQL Azure uses sharding across SQL Server instances. Key points are that each database is limited to 150GB in size, there is a built-in firewall, and data is committed using a quorum-based scheme across replicas. Migration options like SSIS and the Generate Script Wizard are also outlined.