Multidimensional Modeling (SSAS)
An Analysis Services multidimensional solution uses cube structures for analyzing business data across multiple dimensions. Multidimensional mode is the default server mode of Analysis Services. It includes a query and calculation engine for OLAP data, with MOLAP, ROLAP, and HOLAP storage modes to balance performance with scalable data requirements. The Analysis Services OLAP engine is an industry leading OLAP server that works well with a broad range of BI tools. Most Analysis Services deployments are installed as classic OLAP servers.
The primary reason for building an Analysis Services multidimensional model is to achieve fast performance of ad hoc queries against business data. A multidimensional model is composed of cubes and dimensions that can be annotated and extended to support complex query constructions. BI developers create cubes to support fast response times, and to provide a single data source for business reporting. Given the growing importance of business intelligence across all levels of an organization, having a single source of analytical data ensures that discrepancies are kept to a minimum, if not eliminated entirely.
Another important benefit to using Analysis Services multidimensional databases is integration with commonly used BI reporting tools such as Excel, Reporting Services, and PerformancePoint, as well as custom applications and third-party solutions.