Decision makers are asked to make
timely and accurate decisions that are based on the past performance
and behavior of an organization as well as on future trends and directives.
To make effective business decisions, business analysts must have
access to the data that their company generates and responds to. This
access must include timely queries, summaries, and reviews of numerous
levels and combinations of large, recurrent amounts of data. The information
that business analysts review determines the quality of their decisions.
Organizations usually
have databases and data stores that maintain repeated and frequent
business transaction data. These data storage systems provide simple
yet detailed storage and retrieval of specific data events. However,
these systems are not well suited for analytical summaries and queries
that are typically generated by decision makers. For decision makers
to reveal hidden trends, inconsistencies, and risks in a business,
they must be able to maintain a certain degree of momentum when querying
the data. An answer to one question usually leads to additional questions
and review of the data. Simple data stores do not successfully support
this type of querying.
A second type
of storage, the data warehouse, is better suited for this. Data is
maintained and organized so that complicated queries and summaries
can be run. OLAP further organizes and summarizes specific categories
and subsets of data from the data warehouse. This results in a robust
and detailed level of data storage with efficient and fast query returns.
SAS OLAP cubes can be built from either partially or completely denormalized
data warehouse tables. Stored, precalculated summarizations called
aggregations can be added to the cube to improve cube access performance.
Aggregations can either be pre-built relational tables, or you can
let the cube create its own optimized aggregates.