If you are new to data modeling, keep in mind that the information presented here in Module 4 may require some extra time and patience to understand. The Cadastral Data Content Standard model is an illustration of the objects in the Standard. The logical model describes the definitions or semantics of the cadastral information referred to in the Standard. An entity relationship diagram is a shorthand method for showing the associations among various objects in the model, and the relationships between the objects. Note that a logical data model is not an implementation model.
Implementation requires modifying the logical data model to best fit operating software.
This process, called denormalization, is the process of combining entities into tables in a database that optimize the database operation. See the diagram conventions discussion for more information about the E-R diagram used in the Cadastral Data Content Standard. The following is a description of the differences between logical models and physical models. Data modeling professionals often note that there are varying ways of dealing with such details as keys, relationships, and normalization. Accordingly, the description below has been kept as general as possible.