View-Concepts: Knowledge-Based Access to Databases

Abstract

Semantic data models for database systems provide powerful tools to assist database administrators in de-signing and maintaining schemas, but provide little or no direct support for users of the database. Some research has been done on mapping user models of a domain to the underlying database using semantic schemas. Little has been done, however, on mapping conceptually meaningful data structures to a database lacking a semantic schema, or to a multi-database sys-tem that lacks a consistent semantic schema. We argue for the appropriateness of a knowledge representation language as a language for describing the database schema, user data structures, and the mapping be-tween them; present a problem domain in which an ex-isting relational database without a semantic schema must be accessed by a knowledge-based application; and describe our implementation of a system that pro-vides access to a relational database from a KL-ONE-style knowledge representation language. 1