Yannis E. Ioannidis


Computer Sciences Department
University of Wisconsin
1210 W. Dayton St.
Madison, WI 53706-1685

telephone: (608) 262-1204
fax: (608) 262-9777
email: yannis@cs.wisc.edu
Ph.D., University of California, Berkeley, 1986
Interests: Database and Information Systems (Query Optimization, Heterogeneous Systems, Object-Oriented Systems, Intelligent Databases), Human-Computer Interaction (Database User Interfaces, Complex Data Visualization), Scientific Systems (Experiment Management, Scientific Database Systems, Workflow Management)

Research Summary

My research primarily focuses on two areas of database systems: scientific experiment management and optimization of complex queries.

The computational mode of investigation is expected to be part of many experiments in various scientific disciplines in the future. The databases to be generated need specialized support on many aspects that current technology is not ready to provide. I am involved in the development of the ZOO Desktop Experiment Management Environment that will help scientists throughout the life cycle of their experimental studies. A primary component of that system will be a database system. Two major issues that my work addresses are visual user interfaces and semantic heterogeneity. In the former, I'm concentrating on identifying what the right metaphors are for representing complex database schemas, queries, and objects to scientists so that they are natural to them, and also on investigating the power of dynamic visual queries. In the latter, I'm concentrating on developing visual tools that will facilitate translation and integration of different data formats or schemas. Although these issues are generic and arise in all experimental scientific disciplines, my efforts are guided by the needs of specific projects with which I am associated, in particular, simulation-based performance studies of computer systems, simulation-based modeling of plant growth, and NMR spectroscopy.

I have also been working on several problems related to database query optimization. Part of my effort has been on scheduling queries in parallel or multimedia database systems: most related problems in these areas are computationally hard, so my effort is to identify efficient heuristic algorithms that are near-optimal. Another part of my effort has been on bitmap indices for data-warehousing applications, in particular on the time-space tradeoffs of various bitmap designs schemes. Finally, part of my effort has been on approximate query answering, and how a database system may use the statistics it keeps (primarily histograms) to quickly provide an approximate answer to a query as immediate feedback to the user.

Sample Recent Publications

Resource scheduling for composite multimedia objects (with M. Garofalakis and B. Ozden), Proceedings of the 24rd International Conference on Very Large Data Bases, August 1998.

Scientific workflow management by database management (project page) (with A. Ailamaki and M. Livny), Proceedings of the 10th International Conference on Scientific and Statistical Data Management, July 1998.

Bitmap index design and evaluation (with C.-Y. Chan), Proceedings of the International ACM SIGMOD Conference, May 1998.

This page was automatically created December 30, 1998.
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