How long does the SSAS cache stay after the query?

Question

The SSAS is active on my cube. Each query is automatically cached, but for how long? Is there an expiration?

I would like to have a "warm cache" for a set of queries. (I use MOLAP proactive caching)

Answer 1

The data of a query does not stay in the cache for a fixed time. Analysis Services has a cost based memory manager that gives memory to different processes like query calculation, session management, caching, and cube processing depending on available memory (which may increase or decrease over time depending on other processes on the server) and importance of these requests. "Cost based" in this context means that each type of memory usage has a cost (amount of RAM needed) and offers an income based on some parameters.

For cache warming, see e. g.

• http://blogs.msdn.com/b/sqlcat/archive/2007/04/26/how-to-warm-up-the-analysis-services-data-cache-using-create-cache-statement.aspx and
• http://cwebbbi.wordpress.com/2007/01/02/build-your-own-analysis-services-cache-warmer-in-integration-services/.