Schema

In the context of [[Databases (KB)|databases]], a schema is a blueprint or an organizational framework that defines the structure and organization of data within a database. It serves as a formal description of how the database is constructed and is crucial for understanding and working with any database system.

A schema defines the structure of the database in terms of tables, fields (columns), data types, indexes, and relationships between tables. It specifies how data is organized and how the relations among them are associated.

A schema often includes constraints and rules to enforce data integrity. These might include primary keys, foreign keys, unique constraints, and check constraints to ensure the accuracy and consistency of data within the database.

In addition to tables, a database schema can include other objects like views, stored procedures, functions, and triggers. These objects help in managing and accessing data efficiently. The process of designing a schema involves determining the tables, the fields in each table, and how these fields are related.

This is an essential step in database design and can significantly impact the efficiency and functionality of the database system.

While the concept of a schema is common across various database systems (like [[MySQL (KB)]], [[Microsoft SQL Server|SQL Server]], [[Oracle Database|Oracle]], [[PostgreSQL]]), the specific syntax and features for defining and manipulating schemas can vary.