Introduction to Data Warehousing and Analysis Services 2005 - Professional SQL Server Analysis Services 2005 with MDX - page 25

Figure 1-9
Key elements of the UDM are as follows:
▪ Heterogeneous data access support: UDM helps you to integrate
and encapsulate data from heterogeneous data sources. It helps you
combine various schemas into a single unified model that gives end
users the capability of sending queries to a single model.
▪ Real-time data access with high performance: The UDM provides
end users with real-time data access. The UDM creates a MOLAP
cache of the underlying data. Whenever there are changes in the un-
derlying relational database, a new MOLAP cache is built. When
users query the model, it provides the results from the MOLAP
cache. During the time the cache is being built, results are retrieved
from the relational database. UDM helps in providing real-time data
access with the speed of an OLAP database due to the MOLAP
cache. This feature is called proactive caching. You learn more about
proactive caching in Chapter 17 .
▪ Rich metadata, ease of use for exploration, and navigation of
data: UDM provides a consolidated view of the underlying data
sources with the richness of metadata provided by the OLAP world.