Technical data

CHAPTER 8

Creating Explicit Dimension Sets

This chapter provides overviews of explicit dimension sets, and implicit tuples and explicit tuples, and discusses how

to define explicit dimension sets.

See Also

Chapter 9, “Creating Hierarchies,” Understanding the Calculation of Aggregate Data, page 78

Understanding Explicit Dimension Sets

You create an explicit dimension set to form a distinct group of an analytic model’s dimensions. Explicit

dimension sets improve the calculation efficiency of multidimensional data cubes. You can create one or more

explicit dimension sets within an analytic model. Explicit dimension sets may contain completely different or

some of the same dimensions as one another. The analytic calculation set instantiates valid combinations of

members called explicit tuples from explicit dimension sets.

See C

hapter 8 , “Creating Explicit Dimension Sets, ” Understanding Implicit Tuples and Explicit Tuples,

page 66.

A model can contain explicit dimension supersets and explicit dimension subsets. An explicit dimension

superset is a set of dimensions that contains the same dimensions as its subset; however, the superset contains

one or more dimensions than its subset. A subset is the inverse of a superset: it contains the same dimensions

as its superset; however, the subset contains one or more fewer dimensions than its superset. An analytic

model can contain multiple supersets and subsets.

Explicit dimension sets are applied to individual data cubes when calculating data, and are also used for

exporting data. To determine which explicit dimension set it uses on a data cube, the analytic calculation

engine first reads which dimensions are attached to the data cube, and then analyzes and iterates through the

explicit dimension sets in priority order. T he set at the lowest numbered row in the E xplicit Dimension Sets

dialog box receives the highest priority.

See C

hapter 8, “Creatin g Explicit Dimension Sets,” Editing or Adding New Explicit Dimension Sets , page 68.

Note. Explicit dimension subsets must exist at a lower pr iority than their supersets. H owever, it is not

necessary f or an explicit dimension subset t o exist in the row directly beneath its superset. For example,

suppose that a superset exists in row 1. Its subset can be in row 3; it does not have to be in row 2. The explicit

dimension set in row 2 can contain dimensions that are not included in other explicit dimension sets.

Using the priority order, the analytic calculation engine matches the first explicit dimension set that has either

the same or fewer dimensions as are attached to the data cube, and then continues down the priority order for

the remaining dimensions. The analytic calculation engine uses single dimensions if any of these dimensions

remain unmatched after it h as iterated through all explicit dimension sets.

For example, suppose these dimensions are attached to the OVERHEAD_COSTS data cube: