Introduction and Types of DBMS

What is data?
Data is a real type object or entity.

What is information?
It is processed, structured, organized, and interpreted data

What is a Database?
A database is a collection of tables, records, and key constraints.

What is DBMS?

1. DBMS is a software for storing data in a database.
2. DBMS allows to update, modify and create data in the database.
3. DBMS also provides security and protection to the database.
4. DBMS acts as a middle layer between the database and the user.

Advantages of DBMS

1. Minimal data redundancy(repetition).
2. Easy access to data from the database using a query language.
3. It facilitates backup and recovery.
4. Better Data Integrity(maintaining consistency).
5. Use of Integrity Constraints(Keys).
6. It increases consistency and reduces errors

Disadvantages of DBMS

1. Complex and Time consuming to design DBMS.
2. The cost of hardware and software is high to run DBMS software.
3. DBMS consumes a lot of Main Memory and disk space to run efficiently.
4. Initial training is required for all users to use DBMS.

Examples of DBMS

1. SQL Server
2. Oracle
3. MySQL
4. DB2

Components of DBMS

1. Software
2. Hardware
3. Data
4. Procedure
5. Users

Applications of DBMS

1. Railway Reservation System
2. Library management system
3. Banking
4. Education sector
5. Credit card transaction
6. Social media sites
7. Finance
8. Online Shopping
9. Human Resource Management
10. Manufacturing
11. Telecommunication (eg. TRAI->Telecom Regularity Authority of India)

Types of DBMS

1. Hierarchical DBMS (Tree-like structure)
2. Network DBMS (Graph-like structure)
3. Relational DBMS (Related)
4. Object Oriented DBMS

Hierarchical DBMS
It is a system in which the data elements have a one-to-many relationship (1 : N).
This DBMS organizes data in a tree-like structure, similar to a folder structure in your computer system.

Network DBMS
It 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.
This DBMS is the most widely used database system before the introduction of relational DBMS (RDBMS).

Relational DBMS
1) This DBMS was introduced by E.F. Codd in 1970.
2) In this DBMS, every data item of a table is related to every other data item in another table (OR) Every table is linked (logically) with every other table.
3) Example: SQL Server, MySQL, Oracle

Object-Oriented DBMS
Every data is stored in the form of objects. Inheritance, Encapsulation, and other properties of Objects can also be achieved.