SQL Server Analysis Services Aggregation Designs

Problem What exactly are SQL Server Analysis Services (SSAS) Aggregations and how exactly can I review and use them? Solution Aggregations in SSAS offer a wonderful opportunity to improve query performance and calculation times by "pre aggregating" sets of data. These aggregations allow a cube query to ask for a specific value or set of values for a specific group of dimension attributes (a set), and have the calculation already completed before the query was even asked. The aggregation and related query could ask for a single value or actually cover a whole set of values to be returned. Without the aggregations, the query would return results much slower and with more CPU and memory intensity as the query must complete the aggregation calculations at run time, which of course takes significantly longer than if the data points are already summarized to the desired level of the query.