Why Data Warehousing? Data is the core of any organization. Businesses and organizations make use of reliable, distinctive and consolidated data in critical decision making. Normally, the organizational data resides in different data repositories in different formats. For example, a company might have different departments such as HR, finance, accounts etc that are poorly integrated most of the time. The company would have a solid customer base as well. The customer data might have been stored as plain text files or in databases, customer responses as emails on the Web, ...