Database Functions
Database functions are reusable, named blocks of code stored and executed within a database management system (DBMS) to perform specific operations on data, such as calculations, data transformations, or complex queries. They encapsulate logic that can be called from SQL statements, applications, or other database objects, enhancing modularity, performance, and security by reducing code duplication and enabling server-side processing. Common types include scalar functions (return single values), aggregate functions (operate on sets of rows), and table-valued functions (return result sets).
Developers should learn and use database functions to optimize database performance by minimizing network traffic and leveraging server-side execution, especially for complex calculations or data manipulations that would be inefficient in application code. They are essential for enforcing business logic directly in the database, ensuring data consistency and security through centralized control, and are widely used in scenarios like data validation, reporting, and ETL (Extract, Transform, Load) processes across relational databases like PostgreSQL, MySQL, and SQL Server.