Video - MDX Basic Concepts
Having a good understanding of the basic theory of MDX is essential if you want to be able to write your own calculations, and queries, for SQL Server Analysis Services and even PowerPivot in Excel. In this 28-minute video, world-renowned SSAS expert Chris Webb introduces three basic concepts in MDX: unique names, tuples, and sets.
All objects in MDX, from cubes to dimensions to hierarchies, levels and members, have unique names (1:08). These are the names you should use when writing MDX to uniquely identify an object in a cube. You can determine the unique name of an object by clicking on it, in the metadata pane of an MDX query window in SQL Server Management Studio, and then dragging it into the query pane (1:57). Not using a unique name may seem like a good idea, because it makes your MDX code less verbose, but if you do you run the risk of Analysis Services returning a di?erent object with the same name, which will result in errors, or unexpected results.
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