Relational Database Management system Concepts

RDBMS Concepts

Relational Database

• Definition: A database that organizes data into tables with well-defined relationships.
• Tables: Also known as relations, these are the basic storage units in an RDBMS.

Keys

• Primary Key: A unique identifier for each row in a table.
• Foreign Key: A field in a table that references the primary key of another table.
• Composite Key: A primary key composed of multiple columns.

Relationships

• One-to-One (1:1): One row in one table is related to only one row in another table.
• One-to-Many (1:N): One row in one table is related to multiple rows in another table.
• Many-to-Many (M:N): Multiple rows in one table are related to multiple rows in another table.

Normalization

• Definition: The process of organizing data in a database to minimize data redundancy and dependency.
• Normal Forms: A set of rules used to normalize a database, including First Normal Form (1NF), Second Normal Form (2NF), and Third Normal Form (3NF).

SQL

• Definition: Structured Query Language, a standard language for managing relational databases.
• Commands: SQL commands include SELECT, INSERT, UPDATE, and DELETE.

ACID Properties

• Atomicity: Ensures that database transactions are executed as a single, indivisible unit.
• Consistency: Ensures that database transactions preserve data consistency.
• Isolation: Ensures that database transactions are executed independently, without interference.
• Durability: Ensures that database transactions are permanent and survive even in the event of a failure.