What is the difference between physical versus logical data modeling?
Oddly enough, logical data modeling is more of a science and physical modeling is more of an art in that two business analysts can discuss the logical model and resolve most differences of opinion logically (so to speak) by providing real-world examples that would negate a particular representation. Physical database design is not so precise, however. The modeler must know (or anticipate) a number of things about future uses of the data and about the characteristics of the particular database management system, programming language(s), communication channels, etc. Many assumptions go into the creation of a physical model. How well that model will eventually perform depends, in large part, in the quality of those assumptions.
