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Dimensional Modeling
Dimensional modeling (DM) is part of the '' Business Dimensional Lifecycle'' methodology developed by Ralph Kimball which includes a set of methods, techniques and concepts for use in data warehouse design. The approach focuses on identifying the key business processes within a business and modelling and implementing these first before adding additional business processes, as a bottom-up approach. An alternative approach from Inmon advocates a top down design of the model of all the enterprise data using tools such as entity-relationship modeling (ER). Description Dimensional modeling always uses the concepts of facts (measures), and dimensions (context). Facts are typically (but not always) numeric values that can be aggregated, and dimensions are groups of hierarchies and descriptors that define the facts. For example, sales amount is a fact; timestamp, product, register#, store#, etc. are elements of dimensions. Dimensional models are built by business process area, e.g. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
The Kimball Lifecycle
The Kimball lifecycle is a methodology for developing data warehouses, and has been developed by Ralph Kimball and a variety of colleagues. The methodology "covers a sequence of high level tasks for the effective design, development and deployment" of a data warehouse or business intelligence system. It is considered a "bottom-up" approach to data warehousing as pioneered by Ralph Kimball, in contrast to the older "top-down" approach pioneered by Bill Inmon. Program or project planning phase According to Ralph Kimball et al., the planning phase is the start of the lifecycle. It is a planning phase in which project is a single iteration of the lifecycle while program is the broader coordination of resources. When launching a project or program Kimball et al. suggests following three focus areas: * Defining and scoping the project * Plan the project * Manage the project Program and project management This is an ongoing discipline in the project. The purpose is to keep the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |