DATA WAREHOUSE: THE BUILDING BLOCKS Chapter2
Bill Inmon, considered to be the father of DataWarehousing provides the following definition: “A Data Warehouse is a subject oriented, integrated, nonvolatile, and time variant collection of data in support of management’s decisions.”
Integrated Data
Data Granularity In an operational system, data is usually kept at the lowest level of detail. In a point-ofsale system for a grocery store, the units of sale are captured and stored at the level of units of a product per transaction at the check-out counter.
Need Summary Data
OVERVIEW OF THE COMPONENTS Source Data Component
OVERVIEW OF THE COMPONENTS Production Data. Based on the information requirements in the data warehouse The significant and disturbing characteristic of production data is disparity. Your great challenge is to standardize and transform the disparate data from the various production systems, convert the data, and integrate the pieces into useful data for storage in the data warehouse.
OVERVIEW OF THE COMPONENTS Internal Data. users keep their “private” spreadsheets Profiles of individual customers become very important for consideration. Internal data adds additional complexity to the process of transforming and integrating the data before it can be stored in the data warehouse.
Information Delivery Component