System Architect supports database design with logical data models and physical data models. An encyclopedia may contain multiple project data models, each of which may have a logical model diagram, multiple logical subject area diagrams, and multiple physical diagrams.

Logical models represent the logical database design. You can choose between two popular modeling notations: Entity Relation diagrams or IDEF1X diagrams. For either notation, you may create a model diagram and multiple subject area diagrams for each project data model. A logical diagram contains entities that are the logical equivalent to physical database tables.

You may also create multiple physical diagrams for each project data model. System Architect can automatically create a physical diagram from a logical diagram (either an ER diagram or an IDEF1X diagram), and vice versa. The physical diagram contains symbols that directly represent the tables in the database design.

The following sections discuss some fundamental data modeling concepts and philosophies which form the foundation of the Data Modeling tool provided in System Architect.