It is a query language for OLAP databases, much like SQL is a query language for relational databases.
Topic. Description. The Basic MDX Query (MDX). Provides basic syntax information for the MDX SELECT statement. Restricting the Query with Query and Slicer Axes (MDX). Describes what query and slicer axes are and how to specify them.  The MDX was the first crossover SUV to have third-row seating, and shares a platform with the Honda Pilot. The Pilot seats eight, while the MDX seats seven, with two seating positions in the third row. The MDX was introduced as a 2001 model, replacing the slow-selling U.S. -only body-on-frame SLX, based on the Isuzu Trooper. Multidimensional Expressions (MDX) is a query language for OLAP databases, much like SQL is a query language for relational databases. It is also a calculation language, with syntax similar to spreadsheet formulas. MDX was first introduced as part of the OLE DB for OLAP specification in 1997 from Microsoft. It was invented by the group of SQL Server engineers including Mosha Pasumansky. The specification was quickly followed by commercial release of Microsoft OLAP Services 7.0 in 1998 and later by Microsoft Analysis Services. Multiple index file (dBase IV). MDX is a data file format used by dBASE IV. MDX files are multiple index files which are used to hold database information. Many .MDX files are created along side a .DBF file. MDX files can be opened by dBASE and Borland InterBase programs.  Files that contain the .mdx file extension are most commonly associated with the Warcraft III gaming application. Warcraft III is a real-time strategy game. Players enter the world of Azeroth and build bases and control units to take over territory. The MDX files that are installed on a user's computer can be the standard files that are provided by the gaming application or they may contain customized 3D models that have been created using a 3D modeling editor. By understanding how an MDX SELECT statement must specify a result set, what the syntax of the SELECT statement is, and how to create a simple query using the SELECT statement, you will have a solid understanding of how to use MDX to query multidimensional data. Specifying a Result Set. In MDX, the SELECT statement specifies a result set that contains a subset of multidimensional data that has been returned from a cube. To specify a result set, an MDX query must contain the following information: The number of axes that you want the result set to contain. You can specify up to 128 axes in an MDX query The Acura MDX, or Honda MDX as known in Japan and Australia (only the first generation was imported), is a mid-size three-row luxury crossover SUV produced by the Japanese automaker Honda under its Acura luxury nameplate since 2000. The alphanumeric moniker stands for Multi-Dimensional luxury. According to Honda, the MDX is the best-selling three-row luxury crossover of all time, with cumulative U.S. sales expected to surpass 700,000 units before the end of 2014. The Pilot seats eight, while the MDX seats seven, with two seating positions in the third row. The MDX was introduced as a 2001 model, replacing the slow-selling U.S. -only body-on-frame SLX, based on the Isuzu Trooper. Multidimensional Expressions (MDX) is a query language for OLAP databases, much like SQL is a query language for relational databases MDX is a query language that is used to interact and perform tasks with multidimensional databses (also called: OLAP Cubes). MDX is an extension to the SQL language which Microsoft utilizes to query and script access to multidimensional data.
https://msdn.microsoft.com/en-us/library/ms145514.aspx https://en.wikipedia.org/wiki/Acura_MDX https://en.wikipedia.org/wiki/MultiDimensional_eXpressions http://whatis.techtarget.com/fileformat/MDX-Multiple-index-file-dBase-IV http://file.org/extension/mdx https://msdn.microsoft.com/en-us/library/ms144785.aspx https://en.wikipedia.org/wiki/Acura_MDX http://searchsqlserver.techtarget.com/definition/multidimensional-expressions-MDX
what is mdx