David J. DeWitt

Professor and Romnes Fellow

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

telephone: (608) 262-1204
fax: (608) 262-9777
email: dewitt@cs.wisc.edu
Ph.D., University of Michigan, 1976
Interests: Object oriented database systems, parallel database systems, database benchmarking, geographic information systems

Research Summary

The major focus of my research program are the Paradise and SHORE projects. Paradise is a NASA and DARPA funded project to design and implement a scalable object-relational system for managing very large geo-spatial data sets such as those that will be produced by NASA's EOSDIS project and DARPA's Dynamic Database and BADD advanced technology demonstrations. Paradise employs advanced object-relational and parallel database system technology in order to provide scalability to multiple terabyte databases. Like other object-relational database systems Paradise supports non-traditional applications through an extendible type system. In addition to the normal scalar types (i.e. integers, floats, strings), Paradise's type system includes multidimensional arrays (with one unlimited dimension), geo-located raster images (for storing satellite imagery), text, video, and a full set of spatial data types includes points, polylines, and polygons. Paradise is unique in its integrated support for tertiary storage. Individual columns of a table or whole tables can be stored on tape. By integrating support for tertiary storage directly into the database system (instead of using a separate hierarchical storage manager), the Paradise query optimizer and execution engine can optimize the execution of queries accessing tape-resident data.

The objective of the SHORE project is to design, implement, and evaluate a persistent object system that will serve the needs of a wide variety of target applications including hardware and software CAD systems, persistent programming languages, geographic information systems, satellite data repositories, and multimedia applications. SHORE expands on the basic capabilities of the widely-used Exodus Storage Manager (developed at Wisconsin, funded by ARPA) in a number of ways including support for typed objects, multiple programming languages, a `Unix-like' hierarchical name space for named objects, and a Unix-compatible interface to objects with a `text' field. This interface is intended to ease the transition of applications from the Unix file system environment to SHORE as existing Unix tools such as vi and cc will be able to store their data in SHORE objects without modification (basically a Unix file becomes either a single SHORE object or the text field of a complex object). SHORE is being targeted at a wide range of hardware environments, scaling all the way from individual workstations to heterogeneous client/server networks to large multiprocessors such as the Intel Paragon. SHORE is a joint project with Profs. Carey, Naughton, and Solomon.

Sample Recent Publications

Building a scalable geospatial database system: Technology, implementation, and evaluation (with J. Patel, J. Yu, et al.), Proceedings of the SIGMOD Conference on Management of Data, Tucson, Arizona, May 1997.

Shoring up persistent applications (with D. DeWitt, M. Franklin, N. Hall, M. McAuliffe, J. Naughton, D. Schuh, C. Tan, O. Tsatalos, S. White, and M. Zwilling), Proceedings of the ACM SIGMOD Conference on Management of Data, Minneapolis, MN, May 1994.

Query pre-execution and batching in Paradise: A two-pronged approach to the efficient processing of queries in tape-resident data sets (with J. Yu), Proceedings of the Ninth International Conference on Scientific and Statistical Database Management, Olympia, Washington, August 1997.

This page was automatically created December 30, 1998.
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