Database Schema

Synonyms

Database definition; Database description

Definition

A database schema defines the types of database objects (e.g., tables, entity types), the types of relationships among these objects (e.g., inter-table references known as foreign keys, relationship types), as well as constraints that should hold on the database (e.g., key constraints, referential integrity constraints). Each database application (e.g., university database, airline database, online sales database, movie database) would have its own schema describing the types of objects, relationships, and constraints that should hold on the data for each application. A database schema is also sometimes called the database definition or database description. A specialized DDL (Data Definition Language) is typically used to define a schema. Each element of a schema is known as a schema construct. In traditional structured database applications, a schema is defined first; then the data is loaded into the database to conform to...