FGDC Standards - Diagram Conventions Home Feedback NILS Glossary NILS Background Cadastral Data Content Standard Survey Casebook Diagram Conventions 2. 2.1.3 Cardinality 2.2 Attributes 2. Introduction click here to make a comment The Cadastral Data Content Standard in this document is shown as an entity relationship diagram. Entity relationship diagrams illustrate the entities, their attributes, and their associations. The data models are not implementation data models.
Implementation requires modifying the data model to best fit the operating software.
This process is called denormalization and is the process of combining entities into tables in a database that optimize the database operation. The data models describe the definitions or semantics of cadastral information. Entity relationship diagrams are a shorthand method for showing the associations among various objects and hence the definitional relationships of the objects. The diagram conventions for the entity relationship diagram in the Cadastral Data Content Standard are described in the following sections. All three are important to the semantic definition of the object in the standard.