Microsoft Analysis Services - Wikipedia, the free encyclopedia: "History
Microsoft's foray into OLAP Server business began in 1996 with acqusition of OLAP technology from Israeli company Panorama. In 1998 Microsoft released the first version, named OLAP Services, part of SQL Server 7. OLAP Services supported MOLAP, ROLAP, HOLAP and Hybrid OLAP architectures, used OLEDB for OLAP as the client access API and MDX as a query language. It could work in the client server mode or in offline mode with local cube files. In 2000 Microsoft released the next version, named Analysis Services 2000. The rename from OLAP Services happened because of the inclusion of Data Mining services, so the product wasn't just about OLAP anymore. Analysis Services 2000 was an evolutionary release, it was built on the same architecture as OLAP Services and was backward compatible with it. The major improvements included more flexibility in dimension design, by supporting parent child dimensions, changing dimensions, virtual dimensions etc. Another major area of improvements was much enhanced calculation engine with support for unary operators, custom rollups and cell calculations. Other new features were dimension security, distinct count, connectivity over HTTP, session cubes, grouping levels etc. In 2005 Microsoft released the next generation of OLAP and Data Mining technology as Analysis Services 2005. Unlike previous released, Analysis Services 2005 was a revolutionaly release. It maintained backward compatibility on the API level, i.e. applications written with OLEDB for OLAP and MDX continue to work, but the architecture of the product was completely different. The major change came to the model in the form of UDM - Unified Dimensional Model."