who are fathers of data warehousing?

Bill Inmon and from Ralph Kimball,the fathers of data warehousing:

• According to Bill Inmon, a data warehouse is a subject-oriented, integrated, nonvolatile,and time-variant collection of data in support of management’s decisions.

• According to Ralph Kimball, a data warehouse is a system that extracts, cleans, conforms, and delivers source data into a dimensional data store and then supports and
implements querying and analysis for the purpose of decision making.


Both of them agree that a data warehouse integrates data from various operational source systems. In Inmon’s approach, the data warehouse is physically implemented as a normalizeddata store. In Kimball’s approach, the data warehouse is physically implemented in a dimensional data store.