One of the areas which draws a great deal of attention from researchers in database systems is the definition of query languages characterized by both high expressive power and ease of use. 1–4 In this paper, an intelligent database interface system, IDQS is proposed. This system serves as the interface between users and relational database systems. IDQS enables users to query the database in English, and does away with the familiarization cost. IDQS consists mainly of two big blocks: a natural-language processing unit and a knowledge-base. The NL processing unit and knowledge-base are two completely separate entities. This system structure provides a very good base for a transportable system. To transport the system to a new domain, one only needs to update the knowledge-base. No modification has to be done on the NL processing unit. The knowledge-base is designed in such a way that knowledge updating is an easy task which can be carried out by a semi-expert database user.
