Types of DBMS
There are four types of database management system (DBMS) based on the data models, which are as follows:
- Hierarchical Database Management Systems
- Relational Database Management Systems
- Network Database Management Systems
- Object-oriented Database Management Systems
1. Hierarchical Database Management system
A hierarchal database management system is a system in which the data elements have a one to many relationship (1: N). This DBMS organize data in a tree-like structure, similar to a folder structure in your computer system.
The hierarchy starts from the root node, connecting the child node to the parent node. This DBMS is good for storing the data about the items describing its features, attributes, and so on.
2. Network Database Management System
A Network database management system is a system in which the data elements have a one to one relationship (1: 1) or many to many relationship (N: N). This DBMS also has a hierarchical structure, but it organizes data in a graph-like structure, and is allowed to have more than one parent for one single record.
For example, a teacher in a college teaches in two departments.
Note: This DBMS is the most widely used database system before the introduction of the relational database management system.
3. Relational Database Management System
A relational database management system (RDBMS) is a system in which the data is organized in the two-dimensional tables using rows and columns. This database management system was introduced by E.F Codd in 1970.
It is called a ‘relational’ database because data within each table is related to each other. Also, tables may be related to other tables in the database by using certain concepts of keys. Each table in a database has a key field that uniquely identifies each record. This system is the most widely used DBMS. Relational database management system software is available for large mainframe systems as well as workstations and personal computers.
For example, Oracle Database, MySQL, Microsoft SQL Server, and IBM DB2.
In the above table employee, Emp_id, Emp_name, Emp_salary, and Emp_address are the attributes containing their values. Here, Emp_id is a primary key attribute which is uniquely identifying each record in the Employee table.
4. Object-Oriented Database Management system
An object-oriented database management system is a system in which information or data is represented in the form of objects, as used in the object-oriented programming. It is a combination of relational database concepts such as concurrency control, transactions, etc. and OOPs principles, such as data encapsulation, inheritance, and polymorphism.
This database system permits data, information, software components, computing environments, and products to be shared easily.
Object-Oriented Programming + Relational Database Features = Object-Oriented Database management system