Using abstraction from concepts by humans to their implementation in the machine, database modeling relies generally on a three-tier model:
- A conceptual model involving the identification of the geographic features to be included in the database as entities/objects, the definition of their attributes, and how they relate to one another. An abstraction and objective representation of the real world independent from the DBMS software to be used.
- A logical model, a resulting outcome from the transformation of the conceptual model using the DBMS data model techniques (e.g., relational, object, or object-relational).
- A physical model, a resulting outcome from the transformation of the logical model, dealing with storage devices, file structure, and access methods that sort data records. A physical model deals with the storing and encoding of data—the lower-level data structure of the database.”
Excerpt From: Amor Laaribi. “GIS and the 2020 Census.” iBooks.