Defining Database Views as Data Abstractions

The concept of data abstraction is utilized in database systems to define user interfaces via database views in database application languages and to describe the architecture of database systems. Differences between the specification and use of database views and other data abstractions realized as abstract data types are discussed. Database views are formally specified using both the algebraic specification method and the abstract model specification method. The use of database views is demonstrated via the EXT_Pascal database application language.