18 Mining Your Own Business in Telecoms Using DB2 Intelligent Miner for Data
More recently, relational database vendors have also sold their databases as
tools for building data warehouses. A data warehouse stores tactical information
that answers “who?” and “what?” questions about past events. A typical query
submitted to a data warehouse is: “What was the total revenue for the eastern
region in the third quarter?”
It is important to distinguish between the capabilities of a data warehouse from
those of an On-Line Analytical Processing (OLAP) system. In contrast to a data
warehouse — that is usually based on relational technology — OLAP uses a
multidimensional view of aggregate data to provide quick access to strategic
information for further analysis.
OLAP enables analysts, managers, and executives to gain insight into data
through fast, consistent, interactive access to a wide variety of possible views of
information. OLAP transforms raw data so that it reflects the real dimensionality
of the enterprise as understood by the user.
While OLAP systems have the ability to answer “who?” and “what?” questions, it
is their ability to answer “what if?” and “why?” that sets them apart from data
warehouses. OLAP enables decision making about future actions.
A typical OLAP calculation is more complex than simply summing data, for
example: “What would be the effect on soft drink costs to distributors if syrup
prices went up by $.10/gallon and transportation costs went down by $.05/mile?”
OLAP and data warehouses are complementary. A data warehouse stores and
manages data. OLAP transforms data warehouse data into strategic information.
OLAP ranges from basic navigation and browsing (often known as “slice” and
“dice”) to calculations, to more serious analyses, such as time series and
complex modeling. As decision makers exercise more advanced OLAP
capabilities, they move from data access to information to knowledge.
Who uses OLAP and why?
OLAP applications span a variety of organizational functions. Finance
departments use OLAP for applications, such as budgeting, activity-based
costing (allocations), financial performance analysis, and financial modeling.
Sales analysis and forecasting are two of the OLAP applications found in sales
departments. Among other applications, marketing departments use OLAP for
market research analysis, sales forecasting, promotions analysis, customer
analysis, and market/customer segmentation. Typical manufacturing OLAP
applications include production planning and defect analysis.