The data management facilities of PLAIN

The programming language PLAIN has been designed to support the construction of interactive information systems within the framework of a systematic programming methodology. One of the key goals of PLAIN has been to achieve an effective integration of programming language and database management concepts, rather than either the functional interface to database operations or the low-level database navigation operations present in other schemes. PLAIN incorporates a relational database definitional facility, along with low-level and high-level operations on relations. This paper describes those features informally, showing how the database operations are combined with programming language notions such as type checking, block structure, expression evaluation, and iteration. A brief description of the implementation status is included.