“final step of the ETL process is the physical structuring and loading of data into the presentation area's target dimensional models. Because the primary mission of the ETL system is to hand off the dimension and fact tables in the delivery step, these subsystems are critical. Many of these defined subsystems focus on dimension table processing, such as surrogate key assignments, code lookups to provide appropriate descriptions, splitting, or combining columns to present the appropriate data values, or joining underlying third normal form table structures into flattened denormalized dimensions. In contrast, fact tables are typically large and time consuming to load, but preparing them for the presentation area is typically straightforward. When the dimension and fact tables in a dimensional model have been updated, indexed, supplied with appropriate aggregates, and further quality assured, the business community is notified that the new data has been published.”