i am new to SSAS platform. I am curious about how it is technically solved.
I heard that SQL query is not working on this OLAP (MOLAP). Is it true?
I imagined that it is in technical way just some standard DB table of facts with links to dimension DB tables.
Am I wrong?
Where are that data?
In RAM or on hard drive?
Are they structured in classic DB model or in another way?
Analysis Services stores MOLAP data in a structure that is completely different from a relational database. You use a relational database as a source, but the data is copied, compressed, indexed, and restructured in such a way as to optimize storage and retrieval. There is physical storage required. SSAS also takes advantage of RAM and holds what it can there to be more responsive to queries. It is possible to keep source data in a relational database if you set up partitions to use ROLAP storage, but generally better performance is gained by using MOLAP storage.
For more information, see:
http://technet.microsoft.com/en-us/library/ms174915.aspx
http://www.sql-server-performance.com/2009/ssas-storage-modes/
http://www.bidn.com/blogs/dustinryan/ssis/872/ssas-2008-storage-modes