Professional Microsoft® SQL Server® Analysis Services 2008 with MDX

3.1. What Is MDX?

Just as SQL (Structured Query Language) is a query language used to retrieve data from relational databases, MDX (Multi-Dimensional eXpressions) is a query language used to retrieve data from multidimensional databases. More specifically, MDX is used for querying multidimensional data from Analysis Services and supports two distinct modes. When used in an expression, MDX can define and manipulate multidimensional objects and data to calculate values. As a query language, it is used to retrieve data from Analysis Services databases. MDX was originally designed by Microsoft and introduced in SQL Server Analysis Services 7.0 in 1998.

MDX is not a proprietary language; it is a standards-based query language used to retrieve data from OLAP databases. MDX is part of the OLE DB for OLAP specification sponsored by Microsoft. Many other OLAP providers support MDX, including Microstrategy's Intelligence Server, Hyperion's Essbase Server, and SAS's Enterprise BI Server. There are those who wish to extend the standard for additional functionality, and MDX extensions have indeed been developed by individual vendors. MDX extensions provide functionality not specified by the standard, but the constituent parts of any extension are expected to be consistent with the MDX standard. Analysis Services 2008 does provide several extensions to the standard MDX defined by the OLE DB for OLAP specification. In this book you learn about the form of MDX supported by Analysis Services 2008. ...