IBM Cognos TM1 Developer's Certification guide
上QQ阅读APP看书,第一时间看更新

Dimensions

You create a cube with dimensions, and dimensions identify how to organize the information or data that you want to track and report on. Each element in each dimension identifies the location (or "x-y coordinate") of a cell in a cube.

Data is loaded into cube cells. A cell is identified by the intersection of dimensions.

Common dimensions are time periods, products, markets, customers, suppliers, promotion conditions, raw materials, manufacturing plants, transportation methods, media types, and so on.

When you create a dimension, you identify the leaf-level elements that make up the dimension and, optionally, any hierarchies (consolidations) of the elements within the dimension.

Dimension names can have a maximum of 256 characters.

Note

You should always use descriptive dimension names. Your dimension names should be "user friendly" to the average business user (not the average TM1 developer!). You should avoid using special characters and always include "white space" between terms. For example, I like "Headquarters PL Account" rather than "HQ_PL_Acct".

There are four ways to create dimensions:

  • Use the Dimension Editor: This is the most basic method of creating a dimension. You simply add your elements (as well as creating and rearranging consolidations of your elements) manually within the Dimension Editor window. You should know that elements may be "copied and pasted" into the Dimension Editor from outside data stores (such as a Microsoft Excel worksheet).
  • TurboIntegrator: This is by far the most common method of creating dimensions. You can use your custom TurboIntegrator processes to import element names from an ASCII, ODBC, cube view, or dimension subset source. You can also (with some program scripting) create multiple dimensions and establish consolidations within those dimensions. Most often the TurboIntegrator scripts are written in such a way that they can be reused to perform regular maintenance on the dimensions that they originally created.
  • Importing data into a new cube: Of course, it should also be mentioned that TurboIntegrator processes can be used to map input rows from a data source to a cube and then identify the input columns that supply the cell values and the elements that identify the cell location.
  • Dimension worksheets: Finally, an older, less flexible method of creating dimensions is the use of modified Microsoft Excel worksheets (designated as dimension worksheets) to list the elements and hierarchical relationships for one dimension. This method seems to be seldom used anymore and is not covered in the exam.