Professor Papakonstantinou works on emerging trends in query processing, with the focus being on data integration and semistructured data (XML). As a participant in the California Institute for Telecommunications and Information Technology, he is working with other scientists on ways to improve the performance of queries directed at distributed information sources. He is also working on ways to apply database technology and deal more effectively with 'semi-structured' data (ie, data that does not fit easily into the tabular form of conventional relational databases). His interests also include keyword queries, XML databases, and stream data processing. Papakonstantinou can also speak about business and academe, having stepped down as interim CEO of Enosys Software Inc., the company he founded in 2000 while on leave from UCSD. The company provides software for XML-based querying and integration of distributed sources.