LU04a - Concept of a RDB

1. I can explain in my own words, what a relations database is and why it is widely used in all kinds of web applications.
2. I can name and explain the key components of a relational database.

A Relational Database (RDB) is a structured method for storing and organizing data. The core idea is to represent data as related tables.

• Tables: A collection of related data organized into rows (records) and columns (fields). Each row represents a unique entity, and columns contain specific attributes.
• Records: A single row in a table, representing a specific instance of data.
• Fields: A column in a table, defining the type of data stored in each row.
• Relationships: Connections between tables based on shared data. Common types include one-to-one, one-to-many, and many-to-many relationships.

• Primary Key: A unique identifier for each record in a table.
• Foreign Key: A field in one table that references the primary key in another table, establishing a relationship.
• Data Integrity: Ensures data accuracy and consistency through constraints like:
  • Entity Integrity: Every table must have a primary key with no null values.
  • Referential Integrity: Foreign key values must match existing primary key values or be null.
  • Domain Integrity: Data values must conform to defined data types.

• Data Consistency: Enforced by relationships and constraints.
• Data Security: Access control mechanisms protect sensitive information.
• Data Independence: Changes to data structure can be made without affecting applications.
• Efficient Data Access: Indexing and query optimization enhance performance.

• MySQL
• PostgreSQL
• Oracle Database
• Microsoft SQL Server

Definition RDB: https://de.wikipedia.org/wiki/Relationale_Datenbank

Volkan Demir