What is DBMS ?
- DBMS is represented by the DataBase Management System. A database management system (DBMS) is a software that allows creation, definition and manipulation of database, allowing users to store, process and analyze data easily.
- DBMS provide us with an interface or a tool, to perform various operations like creating database, storing data in it, updating data, creating tables in the database and a lot more.
- DBMS also provides protection and security to the databases.
- It also maintains data consistency in case of multiple users.
- Here are some examples of popular DBMS used these days:
- MySQL
- Oracle
- SQL Server
- IBM DB2
- PostgreSQL
- Amazon Simple DB (cloud based) etc.
What is DBMS
Types of DBMS
- Hierarchical Databse Model.
- Network Databse Model.
- Relational Databse Model.
- Object-Oriented Databse Model.
Hierarchical Databse Model
- In a Hierarchical database model, the data is organized in a tree-like structure.
- Data is Stored Hierarchically (top down or bottom up) format.
- Data is represented using a parent-child relationship that are one to one or one to many.
- In Hierarchical DBMS parent may have many children, but children have only one parent.
Hierarchical database Model
Network Database Model
- The network database model allows each child to have multiple parents.
- If you need to address the model help us to more complex relationships like as the orders/parts many-to-many relationship.
- In this model, the entities are organized in a graph which can be accessed through several paths.
Network Database Model
Relational Databse Model
- Relational DBMS is the most widely used DBMS model because it is one of the easiest.
- This model is based on normalizing data in the rows and columns of the tables.
- Relational model stored in fixed structures and manipulated using SQL.
Relational Databse Model
Object-Oriented Databse Model
- In Object-oriented Model data stored in the form of objects.
- The structure which is called classes which display data within it. It defines a database as a collection of objects which stores both data members values and operations.
Object-Oriented Databse Model
Advantages
- Improved data sharing.
- Improved data security.
- Better data integration.
- Minimized data inconsistency.
- Improved data access.
- Improved decision making.
- Increased end-user productivity.
Disadvantages
- Increased costs.
- Management complexity.
- Maintaining currency.
- Frequent upgrade/replacement cycles.