The order of dimensions is critical for the structure and performance of Essbase databases. Optimize performance when ordering dimensions:
Make Period and Account dense, and order dense dimensions from most to least dense. The most dense is usually Period, followed by Account. Dense dimensions calculate faster than sparse dimensions.
Separate sparse dimensions into aggregating and nonaggregating dimensions. Place aggregating dimensions before nonaggregating dimensions. Order sparse dimensions from most to least dense. Aggregating dimensions, such as Entity, consolidate children into the parent to create new data. Nonaggregating dimensions, such as Scenario, do not consolidate children to create data.
You can also use Performance Management Architect to change the order for calculating dimensions. See the Oracle Hyperion Enterprise Performance Management Architect Administrator’s Guide.