| Description: | There are two prevalent approaches to the development of Datawarehouse Architectures:____ 1. Data Warehouse (DWH) bus architecture (introduced by Ralph Kimball)____According to this approach the DWH is developed in phases. Each phase includes the development of a set of dimensional models which are linked together via conformed dimensions, thus forming a virtual ‘bus architecture’. Therefore, according to this approach, at the core of the DWH resides a denormalised dimensional data model, which handles data at the atomic level.The major advantages of this approach are inherited from the use of the dimensional model combined with the ‘conformed dimensions’ principle. This model’s simple and symmetric structure is easily understood by Business Analysts (easier than complex normalized data models). Moreover the so called ’star schema’ allows the efficient execution of queries (less relational joins). The ‘conformed dimensions’ principle allows for the gradual development of a Data Warehouse, in which all information is linked efficiently and analytics spanning different business processes or subject areas are feasible. Each ’star schema’ involves a fact table linked to a number of dimensions in a star.Three fundamental types of fact tables: transaction, periodic snapshot, and accumulating snapshot have been defined. In order to define a DWH development roadmap, Kimball introduced the concept of the DWH bus matrix. The ‘bible’ on this approach is: ‘ The Data Warehouse Toolkit: The Complete Guide to Dimensional Modeling‘, John Wiley |