DBMS > Data Model > What is Data Model?

Data Model:

Data models define how the logical structure of a database is modeled by the database architect. It is a description of the objects/entities represented by a computer system together with their properties, relationships and certain constraints that the database should obey. Output of data modeling is diagram that represents the data structure to support a new software application. 

In the context of programming languages, data model sometimes refers as a data structure and in the context of enterprise models it is function models.

Data Modeling Process

Data modeling process involves three MAIN PHASES with different levels of detail: the conceptual data model, the logical data model, and the physical data model.

Conceptual (high-level, semantic) data models: The conceptual level is a way of describing what data is stored within the whole database and how the data is inter-related. The conceptual level does not specify how the data is physically stored. Some important facts about this level are ...

• DBA works at this level.
  
• Describes the structure of all users.
  
• Only DBA can define this level.
  
• Global view of database.
  
• Independent of hardware and software.
  

it is also called entity-based or Object-based data models.

Physical (low-level, internal) data models: Provide concepts that describe details of how the data is actually stored in the database and on the computer hardware.

Implementation (representational) data models(External Level, User Views): Provide concepts that fall between the above two, balancing user views with some computer storage details. A user's view of the database describes a part of the database that is relevant to a particular user. It excludes irrelevant data as well as data which the user is not authorized to access.

Among different types of data model used in DBMS some of them are bellow:

1. Entity-Relationship Model
2. Relational Model
3. Hierarchical Model
4. Network Model
5. Object-Oriented Data Model
6. Object-Relational Data Model
7. Flat Data Model
8. Semi-Structured Data Model
9. Associative Data Model
10. Context Data Model

No More

Next

What is Entity Relationship Model?

Feedback

Submit