Microsoft SQL Azure Database is a cloud-based relational database service that is built on SQL Server technologies and runs in Microsoft data centers on hardware that is owned, hosted, and maintained by Microsoft. SQL Azure Database does not support all of the features and data types found in SQL Server
Similarities and Differences
<ol><li>Similar SQL Server on your premises, SQL Azure Database exposes a tabular data stream (TDS) interface for Transact-SQL-based database access. </li><li>SQL Azure Database supports many SQL Server 2008 data types; it does not support data types that have been deprecated from SQL Server 2008.</li><li>Because SQL Azure Database is a service, administration in SQL Azure Database is slightly different. SQL Azure Database abstracts the logical administration from the physical administration; Microsoft administers the physical hardware such as hard drives, servers, and storage. This approach helps SQL Azure Database provide a large-scale multi-tenant database service that offers enterprise-class availability, scalability, security, and self-healing.</li><li>Using SQL Azure Database, DBAs manage schema creation, statistics management, index tuning, query optimization, and security administration (logins, users, roles, and so on).</li><li>Analysis Services, Replication, and Service Broker are not currently provided as services on the Windows Azure platform.</li><li>SQL Azure Database automatically replicates all data to provide high availably.</li><li>SQL Azure Database also manages load balancing and, in case of a server failure, transparent fail-over.</li></ol>