Kimball University: Integration for Real People

These step-by-step guidelines will help dimension managers and users drill across disparate databases.


This article has described the data integration task in a specific, actionable way. Hopefully some of the mystery surrounding integration has been reduced and you can take this task off your to-do list so you don't have to feel guilty.

The vocabulary of dimensional modeling brings clarity and structure to the otherwise amorphous topic of integration. Key terms used in this article include:

* Conformed dimension. A master dimension for which contents have been agreed to by all parties in the enterprise.

* Conformed fact. A measure for which a business definition has been agreed to by all parties in the enterprise so the fact can be used in analytic computations across separate data sources and with other conformed facts.

* Surrogate key. A simple integer, usually assigned sequentially, serving as the primary key to a dimension.

* Drill across. A query strategy for producing integrated answer sets from multiple databases.

Ralph kimball, founder of the Kimball Group, teaches dimensional data warehouse and ETL design through Kimball University and reviews large warehouses. He has four best-selling data warehousing books in print, including The Data Warehouse ETL Toolkit (Wiley, 2004) . Write to him at [email protected].


The Data Warehouse Toolkit, 2nd Edition by R. Kimball and M. Ross (John Wiley & Sons, 2002).

The Data Warehouse ETL Toolkit, by R. Kimball and J. Caserta (John Wiley & Sons, 2004)

More than 100 free articles on dimensional modeling topics and conformed dimensions and conformed facts may be found at