What Does Three-Schema Architecture Mean?
Three-schema architecture is an idea in relational database design that breaks a database down into three different categories according to its use and structure, and to the roles played by system administrators, designers and end users.
Techopedia Explains Three-Schema Architecture
Developed in the 1970s, the three-schema architecture helps to evaluate a relational database from different vantage points. The first of the three levels is called the external level or user level. This is the view of the relational database that end users see, and it involves a high level of abstraction. The second level is the logical schema or conceptual level, where designers work. The third level is the physical schema or physical level, where programmers maintain a database on a hardware system. The three-schema architecture is generally attributed to the ANSI/SPARC group and is sometimes also called “ANSI/SPARC” architecture.
