With the rapid growth of real-time information from various sources, continuous keyword search over streams has become increasingly important. In this dissertation, we propose scalable and efficient ways to enable keyword search over XML and relational streams by addressing the following major problems: 1) quality of search results in keyword search over XML streams and 2) scalability against the number of query keywords and the result size in keyword search over relational streams. The experimental results prove that the proposed methods perform much better than the comparative approaches.
I first chose useful research topic that I am interested in. To do research on my chosen topic, I studied in-depth knowledge of all related existing technologies through reading research papers, and discussing with my supervisors. Then, I identified and worked the challenging unsolved problems, whose solutions are useful for the societies. What I understood being a PHD student is that doing useful research with useful result is a lifetime-pride.