Grammars and Relations.

Abstract

Programming languages and databases have evolved on separate foundations and with separate goals for many years. Buzzwords such as persistent data objects, objectoriented databases and software engineering databases reflect increased activity aimed at integrating the two areas at their current state of evolution. This paper suggests that we retum to basics and consider the foundation of the two areas, grammars and relations, as a basis for their integration. We present an algorithm, GeneRel, which given a grammar automatically generates a set of normalized relations in which objects derived from the grammar can be stored. We demonstrate how the algorithm applied to a meta- grammar generates relations in which grammars derived from the meta-grammar can be stored. We show how an extended relational algebra can be used to retrieve information about stored grammars and stored objects derived from the grammars. We outline an algorithm, GeneView, which given a set of non-terminals from a grammar generates a set of view definitions on the created relations.