Ahmed Elsayed¹, Ahmed Sharaf Eldin¹, Doaa S. El Zanfaly^{1, 2}, ¹Helwan University, Egypt and ²British University in Egypt, Egypt

Keyword Search Over Relational Databases (KSORDB) provides an easy way for casual users to access relational databases using a set of keywords. Although much research has been done and several prototypes have been developed recently, most of this research implements exact (also called syntactic or keyword) match. So, if there is a vocabulary mismatch, the user cannot get an answer although the database may contain relevant data. In this paper we propose a system that overcomes this issue. Our system extends existing schema-free KSORDB systems with semantic match features. So, if there were no or very few answers, our system exploits domain ontology to progressively return related terms that can be used to retrieve more relevant answers to user.