What is RDBMS?

A Relational Database Management System (RDBMS) is a type of database management system (DBMS) that stores data in a structured format, using rows and columns. RDBMSs use Structured Query Language (SQL) for database access and management. They are based on the relational model, an approach to managing data using relations, which are often depicted as tables.

Key Features of RDBMS

1. Structured Data Storage: Data is stored in tables, which consist of rows and columns. Each table represents a different entity, such as employees, orders, or products.
2. Data Integrity: RDBMSs enforce data integrity through constraints such as primary keys, foreign keys, unique constraints, and not null constraints.
3. ACID Properties: RDBMSs adhere to the ACID (Atomicity, Consistency, Isolation, Durability) properties to ensure reliable transaction processing.
   • Atomicity: Ensures that transactions are all-or-nothing.
   • Consistency: Ensures that a transaction brings the database from one valid state to another.
   • Isolation: Ensures that transactions do not interfere with each other.
   • Durability: Ensures that once a transaction is committed, it will remain so, even in the event of a system failure.
4. Data Manipulation Language (DML): SQL commands like SELECT, INSERT, UPDATE, and DELETE are used for data manipulation.
5. Data Definition Language (DDL): SQL commands like CREATE, ALTER, and DROP are used for defining and modifying the database schema.
6. Data Control Language (DCL): SQL commands like GRANT and REVOKE are used for controlling access to data.
7. Data Query Language (DQL): Primarily the SELECT statement, which is used to query data.
8. Indexing: RDBMSs use indexing to improve the speed of data retrieval operations.
9. Relationships: Tables can be related to each other using foreign keys, allowing complex queries across multiple tables.