Determining SSAS Aggregation Usage

Aggregations improve query performance by limiting the amount of partition data that needs to be scanned to answer a query. Instead of querying the fact level data of the partition, SSAS will query the aggregation and because the amount of data in the aggregation is smaller, the query can be answered more succinctly. However these benefits come with a trade-off, they take time to build which increases processing time and space. They can also have an adverse impact on performance where there too many designs. This post shows how to determine if an aggregation is being used by using trace events.