History

The concept of data warehousing dates back to the mid-1980s [3] when IBM researchers Barry Devlin and Paul Murphy developed the "information warehouse". In essence, the data warehousing concept was intended to provide an architectural model for the flow of data from operational systems to decision support environments. The concept attempted to address the various problems associated with this flow - mainly, the high costs associated with it. In the absence of a data warehousing architecture, an enormous amount of redundancy of information was required to support the multiple decision support environment that usually existed. In larger corporations it was typical for multiple decision support environments to operate independently. Each environment served different users but often required much of the same data. The process of gathering, cleaning and integrating data from various sources, usually long existing operational systems (usually referred to as legacy systems), was typically in part replicated for each environment. Moreover, the operational systems were frequently reexamined as new decision support requirements emerged. Often new requirements necessitated gathering, cleaning and integrating new data from the operational systems that were logically related to prior gathered data.

Based on analogies with real-life warehouses, data warehouses were intended as large-scale collection/storage/staging areas for corporate data. Data could be retrieved from one central point or data could be distributed to "retail stores" or "data marts" which were tailored for ready access by users.

Key developments in early years of data warehousing were:

• 1983 - Teradata introduces a database management system specifically designed for decision support.
• 1986 - Barry Devlin and Paul Murphy publish the article An architecture for a business and information systems in IBM Systems Journal where they introduce the term "information warehouse".
• 1990 - Red Brick Systems introduces Red Brick Warehouse, a database management system specifically for data warehousing.
• 1991 - Prism Solutions introduces Prism Warehouse Manager, software for developing a data warehouse.
• 1991 - Bill Inmon publishes the book Building the Data Warehouse.
• 1995 - The Data Warehousing Institute, a for-profit organization that promotes data warehousing, is founded.
• 1996 - Ralph Kimball publishes the book The Data Warehouse Toolkit.
• 1997 - Oracle 8, with support for star queries, is released.