Abstract

this paper we<E-382> formalize a graphical conceptual model for data warehouses, called Dimensional Fact model, and<E-380> propose a semi-automated methodology to build it from the pre-existing (conceptual or logical)<E-366> schemes describing the enterprise relational database. The representation of reality built using our<E-381> conceptual model consists of a set of fact schemes whose basic elements are facts, measures,<E-358> attributes, dimensions and hierarchies; other features which may be represented on fact schemes are<E-382> the additivity of fact attributes along dimensions, the optionality of dimension attributes and the<E-381> existence of non-dimension attributes. Compatible fact schemes may be overlapped in order to relate<E-373> and compare data for drill-across queries. Fact schemes should be integrated with information of the<E-382> conjectured workload, to be used as the input of logical and physical design phases; to this end, we<E-382> propose a simple language to denote data warehouse queries in terms of sets of fact instances.<E-334>

Citations