Vocabulary building for database queries

Abstract

The introduction of natural language features into database query languages seems to be classified into three stages. The first stage is characterized by the introduction of the syntactic flexibility of natural languages, while the second stage introduces the access flexibility. In the first stage languages, database users can afford syntactic structures similar to a natural language. However, he has to specify, in a procedural manner, how to retrieve information. The second stage languages offer facilities to define a variety of virtual access paths as well as actual access structures of databases. Their definition may be expressed as a semantic network or a set of logical rules. The third stage, that is the most sophisticated one, needs the introduction of vocabulary semantics. Sharing a common vocabulary, human beings can communicate with each other without referring to the conceptual structures of their knowledge. Vocabulary plays one of the most important roles in human communications. The purpose of this paper is the introduction of the similar facilities to the communication between a database and its users. We call it vocabulary semantics. The paper clarifies how to build vocabulary and how to define its formal semantics.