SQL Server 2008, formerly codenamed Katmai, was released on August 6, 2008 and goals to make data self organizing, management self-tuning, and self maintaining with the improvement of SQL Server Always On technologies, to give almost-zero downtime. SQL Server 2008 also includes support for structured and semi-structured data, as well as digital media formats for pictures, audio, video and other multimedia data. In present versions, such multimedia data can be saved as BLOBs (binary large objects), but they are generic bit streams. It also natively supports hierarchical data, and includes T-SQL constructs to directly deal with them, without using recursive queries. Basic awareness of multimedia data will permit specialized functions to be performed on them. According to Paul Flessner, senior Vice President, Server Applications, Microsoft Corp., SQL Server 2008 can be a data storage backend for different varieties of data: XML, email, time/calendar, file, document, spatial, etc as well as perform search, query, analysis, sharing, and synchronization across all data types.
SQL Server 2005, formerly codenamed Yukon, was released in October 2005. It’s a built-in native support for managing XML data and adding relational data. Purposely, it defined an XML data type that could be utilized either as literals in queries a data type or in database columns. XML columns can be linked with XSD schemas; XML data being saved is verified against the schema. XML is changed to an internal binary data type before being saved in the database. Specialized indexing methods were made available for XML data. XML data is inquired using XQuery; SQL Server 2005 added some extensions to the T-SQL language to permit embedding XQuery queries in T-SQL. In addition, it also defines a new extension to XQuery, called XML DML that allows query-based modifications to XML data. SQL Server 2005 also allows a database server to be exposed over Web services using Tabular Data Stream (TDS) packets encapsulated within SOAP (protocol) requests. When the data is viewed over Web services, results are returned as XML.