Pre-physical data base design heuristics

Data base design encompasses both business and technical aspects. Conceptual data modelling creates a conceptual schema to abstract the user view of data within the business context. This conceptual schema is mapped to the logical data model structure in order to obtain a set of normalized relations. These ensure the integrity of the data by avoiding update anomalies. Regardless of the methodology used, the process or transaction model will impact on the data base design process and its refinement. Since the process or transaction model will reflect the business requirements and specific users view of the data, it will determine the relevance of having a fully normalized set of data, or the need for trading off some degree of normalization, with the aim of improving performance in the query process. The model will also indicate the activity requirements on the relations in the logical data model, their frequency, and characteristics. A pre-physical design step is described, and a set of heuristics is proposed in order to obtain a refined data base design.