CASDAL

Abstract

CASDAL is a high level data language designed and implemented for the database machine CASSM. The language is used for the manipulation and maintenance of a database using an unnormalized (hierarchically structured) relational data model. It also has facilities to define, modify, and maintain the data model definition. The uniqueness of CASDAL lies in its power to specify complex operations in terms of several new language constructs and its concepts of tagging or marking tuples and of matching values when walking from relation to relation. The language is a result of a top-down design and development effort for a database machine in which high level language constructs are directly supported by the hardware. This paper (1) gives justifications for the use of an unnormalized relational model on which the language is based, (2) presents the CASDAL language constructs with examples, and (3) describes CASSM's architecture and hardware primitives which match closely with the high level language constructs and facilitate the translation process. This paper also attempts to show how the efficiency of the language and the translation task can be achieved and simplified in a system in which the language is the result of a top-down system design and development.