Bill Inmon, the recognized father of the data warehousing concept, defines a data warehouse as a subject-orientated, integrated, time variant, non-volatile collection of data in support of management's decision-making process. Another data warehousing pio

Bill Inmon, the recognized father of the data warehousing concept, defines a data warehouse as a subject-orientated, integrated, time variant, non-volatile collection of data in support of management's decision-making process. Another data warehousing pioneer, Richard Hackathorn, describes the data warehouse as a single image of the business reality [citing Lambert].

¶ Data warehouses are becoming an increasingly popular tool for the management of data. The most fundamental reason for this is, firstly, that executives need rapid, easy access to data for planning and control. Secondly, data have historically been stored in disparate systems, in multiple locations, which made a complete view of organizational data almost impossible [citing Laudon & Laudon].