What is Multi Dimension OLAP CUBE and give example cube with more than 3 dimensions

rmdussa picture rmdussa · Nov 24, 2009 · Viewed 22k times · Source

As I am new to SSAS, have been reading an article on Multi-Dimension OLAP Cube and struggling to understand Cube concepts, It has been said that Although the term "cube" suggests three dimensions, a cube can have up to 64 dimensions. Could you please explain how is this possible on cube (other than 3-Dim example x,y,z planes)? Please don't give only links to study but also expecting some explanation.

Answer

Damir Sudarevic picture Damir Sudarevic · Nov 25, 2009

In the DW world, the word "dimension" is overloaded -- changes meaning depending on context. Here is an example.

  • On a certain date, a customer walks into a store and buys a product.

This example has four dimensions (date, customer, store, product) and one fact (sales). So a typical Kimball star would look like:

dim4_model_01

A dimension (table) is a look-up table for properties of objects that rarely change. Product, customer and store may change some of their properties (attributes), but they rarely do. Fact table captures interactions between these objects. At the intersection of dimensions date, store, product and customer lies a measure SalesAmount. Note how easy is to aggregate (sum) the sales amount by date, by year, by product, by brand, by city, by country, by age group, by whatever -- which was the idea in the first place.