Data Models in DBMS
A Data Model in Database Management System (DBMS), is the concept of tools that are developed to summarize the description of the database.
It is classified into 3 types:
1. Conceptual Data Model :
Conceptual data model, describes the database at a very high level and is useful to understand the needs or requirements of the database. It is this model, that is used in the requirement gathering process i.e., before the Database Designers start making a particular database. One such popular model is the entity/relationship model (ER model). The E/R model specializes in entities, relationships and even attributes which are used by the database designers. In terms of this concept, a discussion can be made even with non-computer science(non-technical) users and stakeholders, and their requirements can be understood.
2. Representational Data Model :
This type of data model is used to represent only the logical part of the database and does not represent the physical structure of the databases. The representational data model allows us to focus primarily, on the design part of the database. A popular representational model is Relational model.
3. Physical Data Model :
Ultimately, all data in a database is stored physically on a secondary storage device such as discs and tapes. This is stored in the form of files, records and certain other data structures. It has all the information of the format in which the files are present and the structure of the databases, presence of external data structures and their relation to each other.