Leonard Shapiro
Emeritus Professor, Department of Computer Science
Portland State University
P.O. Box 751
Portland, OR 97201-0751

Ph.D., Yale University, 1969
B.A., Reed College, 1965 (Phi Beta Kappa)


Elected by PSU students as Outstanding Computer Science Teacher, 2002-3. 

Inventor of the Hybrid Hash Join, an algorithm used in all modern relational database management systems.

Two of his publications are among the 100 most cited articles in database research .

Published in computer science, economics, statistics and mathematics.

On program committees of several conferences, recently VLDB 2002 and ICDE 2002 and SIGMOD 2003 demos.

Expert witness work for companies including Oracle, IBM, Palm Computing and Cadence.

Database consultant to companies including AT&T, Informix, Oracle, Sequent, Intel and ADP.

Publications in computer science since 1965.

Program Evaluator for the Computing Accreditation Commision of ABET since 1987.




Member, Board of Directors: Our House of Portland

Vice President: Hospice of Washington County

Vice President of the Board of Trustees: Cedar Sinai Park

Vice President: Congregation Neveh Shalom

Volunteer Consultant in use of computers and the web for bus ontime information: Tri-Met.

Volunteer Computer Science Teacher, Costumier, and Speech Team Representative to Booster Club: Beaverton High School.



Requirements for a Next Generation Personal File Manager, L. Shapiro, T. Hayes, L. Delcambre, W. Harrison and B. Massey,  Workshop on Personal Information Management, in CSCW, Seattle, WA, 2012

Barriers to Information Hand-off in Personal-scale Data Analysis, T. Hayes, L. Delcambre and L. Shapiro, In Workshop on Personal Information Management, in CSCW, Seattle, WA, 2012

Superimposing Spatial Enrichments in Traditional Information”, Lois Delcambre, David Maier, Mathew Weaver, Leonard Shapiro, Judith Bayard Cushing, International Workshop on Next Generation Geospatial Information, Cambridge (Boston), Massachusetts. October 2003”


A Digital GeoLibrary: Integrating Keywords And Place Nameswith M.  Weaver, L. Delcambre et al, 7th European Conference on Digital Libraries, Trondheim, Norway, August, 2003.  Also, Lecture Notes in Computer Science, Number 2769, Traugott Koch, Ingeborg Torvick Solvberg (editors), Springer-Verlag, Berlin, 2003.


Harvesting Information to Sustain our Forests” with L. Delcambre, T. Tolle et. al., Communications of the ACM, 46(1), January 2003.

Algorithms and Applications for Universal Quantification in Relational Databases”, with R. Rantzau, B. Mitschang and Q. Wang,  Information Systems,  Vol 28, No. 1-2, January 2003, Pg 3-32.

G-Metadata++: Rich Keyword Search Enhanced with a GIS”, with A. Gutema, J. Brewster, L. Delcambre, M. Weaver, D. Maier, T. Tolle, D. Guenther, Extended Abstracts from GIScience 2002, Boulder, CO, 2002.

 Universal Quantification in Relational Databases: A Classification of Data and Algorithms”, with R. Rantzau, B. Mitschang and Q. Wang, Proceedings of the  International Conference on Extending Database Technology, Prague, Czech Republic, March 2002.

"Exploiting Upper and Lower Bounds in Top-Down Query Optimization", with D. Maier et al., International Database Engineering and Applications Symposium, Grenoble, France, July 16-18, 2001, pg. 20-33.

“The Hybrid Technique for Reference Materialization in Object Query Processing”, with Q. Wang and D. Maier. Proceeding of the International Database Engineering and Applications Symposium, September 2000, Yokohama, Japan, Pg. 37-46.

"Selected Research Issues in Decision Support Databases", with D. Maier and M. Meredith, Journal of Intelligent Information Systems, 11, 169-191 (1998).

“Binging Knowledge to Bear: Challenges for Decision Support Databases”,with D. Maier and M. Meredith, International Hong Kong Computer Society Database Workshop 1996: 1-15

"Presentation of Self in Virtual Life" , with E. Shapiro, presented at the International Communication Association Annual Conference, Jerusalem, 1998.

"Sort versus Hash Revisited" (joint with G. Graefe and A. Linville), IEEE Transactions on Knowledge and Data Engineering, December 1994.

"Issues in Distributed Object Assembly" (with D. Maier et al), in Distributed Object Management, M.T. Ozsu, U. Dayal and P. Valduriez (eds), Morgan Kaufmann, 1993

"Data Compression for Database Performance" (joint with G. Graefe), Proc. of the ACM/IEEE-CS Symp. on Applied Computing, April 1991.

"Logical vs. Physical Disk Shadowing" (joint with G. Graefe), Proc. of the ACM/IEEE-CS Symp. on Applied Computing, April 1991.

"Query Optimization for Nontraditional Database Applications", (joint with T. Sellis), IEEE Transactions on Software Engineering, January 1991.

"Extensions To Query Languages for Graph Traversal Problems", (joint with M. Mannino), March 1990, IEEE Transactions on Data and Knowledge Engineering.

"Turing Completeness of Extended Database Query Languages", (joint with D. Varvel), IEEE Trans. Software Engineering, 15(5), May 1989, pages 632-637.

"Heuristic Search in Database Systems", (joint with M. Stonebraker et al.) in Expert Data Base Systems, ed. L. Kerschberg, Benjamin Cummings, 1986.

"Join Processing in Database Systems with Large Main Memories", ACM Transactions On Database Systems, Vol. 11, No. 3, September 1986, pages 239-264.

"Data Design", Byte Magazine, April, 1986, pages 129-134.

"An Operating System Programming Project" (joint with Paul Juell), Proceedings of the National Educational Computer Conference, San Diego, June 1986.

"Optimization of Extended Database Query Languages", (with T. Sellis), ACM SIGMOD Proceedings, Austin, Texas, June 1985, pages 424-436.

“Implementation Techniques for Main Memory Database Systems”, SIGMOD Record, Vol. 14 No. 2, June, 1984, pages 1-8. (with D. DeWitt et al.)

“Conditions for Expected Utility: The Finite Case”, Annals of Statistics, 7(1979), pg. 1288-1302.

“Incentive Structures Maximizing Residual Gain Under Incomplete Information” (with L. Hurwicz), Bell Journal of Economics, 9(1978), pg.


“Induced Flows” (with K. Petersen), Trans. Amer. Math. Soc., 177(1973), pg.  375-390.

“Computer Calculations of Fibonacci Entry Points” (with D.  Lind and R. Morris), pamphlet published by the Fibonacci Association of America,

September, 1965.



Assistant Professor, Mathematics, University of Minnesota, 1969-76

Visiting Professor of Economics, University of Minnesota, 1976-77

Chairman, Division of Mathematical Sciences, North Dakota State University, 1977 - 1985

Visiting Scholar, Computer Science Department, University of California at Berkeley, 1983/4

Associate, then full Professor of Computer Science and Business/Economics, North Dakota State University, 1977-1987

Chair, Computer Science Department, Portland State University, 1987-1994

Professor of Computer Science, Portland State University, 1987-

Associate Director, then Director, Data Intensive Systems Center (DISC), 1994-



Woodrow Wilson Fellow, Yale, 1965-66

NSF Graduate Fellow, Yale, 1966-69

Faculty Associate, NSF research grant in Topological Dynamics, 1969-78

Director, HEW Project in Computer Assisted Instruction, 1973-76

NSF Faculty Fellowship in Science (Mathematical Economics), University of California at Berkeley, 1976-79

Principal Investigator, NSF research grant in Efficient Information Flow in Business Organizations, 1979-81

Director, AT&T Computer Systems Training Center at North Dakota State University, 1980-85, training AT&T personnel in computer science.

Consultant, ComputerLand World Headquarters, 1983/4, developing their customer training program.

Coinvestigator, NSF research grant in "Database Management Systems in Operations Research", 1986-87

Coinvestigator, AFOSR research grant in "Distributed Database Systems", 1986-7

Coinvestigator, US Dept of Agriculture research grant in "Management Information Systems in Agricultural Economics", 1986-7

Principal Investigator, Tektronix grant in "Software Engineering Curriculum Development", 1988-1994

Coinvestigator, OACIS research grant in "Database Performance", 1990-91

Coinvestigator, Sequent and OACIS research grant in "Database Performance", 1991-92

Coinvestigator, Intel SSD and OACIS research grant in "Database Performance", 1991-92

Coinvestigator, ADP and OACIS research grant in "Database Performance", 1991-92

Principal Investigator, Sequent and OACIS research grant in "Almost Hard Lower Bounds for Sorting", 1992-93.

Principal Investigator, Sequent research grant in "Parallel Sort Performance", 1993-94.

Consultant, Sequent Computer Systems, 1994-5.

Consultant, Informix Corporation, 1993-96.

Coinvestigator, ARPA grant in Query Optimization and Execution, 1995-97

Principal Investigator, NSF grant in Query Processing, 1995-97

Principal Investigator, NSF grant in Query Optimization Engineering, 1997-2001.

Principal Investigator, NSF research and travel grants in Parallel Query Optimization, 1998-2001.