Difference between Conceptual Logical and Physical Data Model
Conceptual Data Model:
The conceptual data model describes different types of data stored in a database. It also includes the relationships existing among data items. In this data model, a database is also described logically rather than physically in terms of data structure.
Logical Data Model:
The Logical Data Model is the closest data model to the users. This data model is concerned with how the data are observed. So, most of the users of the database are not concerned with all the information.
Physical Data Model:
Physical Data Model is the one closest to the physical storage device. Because it describes how data are stored on a storage medium such as a hard disk, magnetic tape, etc. It also defines compression and encryption techniques.
Conceptual vs Logical vs Physical Data Model:
| Parameter | Conceptual Model | Logical Model | Physical Model |
|---|---|---|---|
| Entity | Yes | Yes | Yes |
| Column | No | Yes | Yes |
| Relationship | Yes | Yes | Yes |
| Column's Type | No | Optional | Yes |
| Primary Key | No | No | Yes |
| Foreign Key | No | No | Yes |