How Analysis Services processes queries
Before we start to discuss how to improve query performance, we need to understand what happens inside Analysis Services when a query is run. The two major parts of the Analysis Services engine are:
The Formula Engine processes MDX queries, works out what data is needed to answer them, requests that data from the Storage Engine, and then performs all calculations needed for the query.
The Storage Engine handles all reading and writing of data; it fetches the data that the Formula Engine requests when a query is run and aggregates it to the required granularity.
When you run an MDX query, then, that query goes first to the Formula Engine where it is parsed; the Formula Engine then requests all of the raw data needed to answer the query from the Storage Engine, performs any calculations on that data that are necessary, and then returns the results in a cellset back to the user. There are numerous opportunities for performance tuning at all stages of...
