Richard Thomas Snodgrass (born April 19, 1955) is an American computer scientist and writer and is professor emeritus at the University of Arizona. He is best known for his work on temporal databases, query language design, query optimization and evaluation, storage structures, database design, and ergalics (the science of computing).
Snodgrass and his doctoral student originated the concept of valid time and transaction time. As of December 2011, ISO/IEC 9075, Database Language SQL:2011 Part 2: SQL/Foundation included clauses in table definitions to define "application-time period tables" (valid-time tables) and "system-versioned tables" (transaction-time tables).
TSQL2, a temporal extension to the SQL-92 language standard, was designed by the TSQL2 committee, which was formed in July, 1993. Snodgrass chaired the TSQL2 language design committee. The committee produced a preliminary language specification the following January, which appeared in the March 1994 ACM SIGMOD Record.
Various members of the temporal database research community have worked to transfer some of the constructs and insights of TSQL2 into SQL3, termed SQL/Temporal. Snodgrass initiated SQL/Temporal part of the SQL3 draft standard. SQL/Temporal has been partially implemented in Oracle, Teradata version 14, and IBM DB2 10.
Snodgrass along with Christian Jensen co-chairs TimeCenter, an international center for the support of temporal database applications on traditional and emerging DBMS technologies. The center has published more than 90 articles since 1997, many of which have been accepted in leading computer science journals.
Snodgrass presented to the ACM Council a proposal for "a new ACM service, the ACM Computing Portal," a web-based repository of bibliographic information of all the computing literature. The proposal arrived at a ballpark figure of one million items that captured the entire history of computing, from roughly 1940 to 2000. The ACM Portal, also called the ACM Guide, was released to the public on May 21, 2003. This resource was later expanded into the ACM Digital Library, which has opened for public access more than 100,000 scientific articles from 1951 through 2000.
As the chair of the ACM Publications Board, Snodgrass developed a strategic vision for the Association for Computing Machinery to become the preferred publisher for computer science and proposed a far-ranging policy that recognizes the rights and responsibilities of readers, authors, reviewers, editors and libraries.
Snodgrass is the author or editor of several books including:
Developing Time-Oriented Database Applications in SQL, Richard T. Snodgrass, Morgan Kaufmann Publishers, Inc., San Francisco, July, 1999, 504+xxiii pages, ISBN1-55860-436-7.
The TSQL2 Temporal Query Language, The TSQL2 Language Design Committee consisted of Richard T. Snodgrass (chair), Ilsoo Ahn, Gad Ariav, Don Batory, James Clifford, Curtis E. Dyreson, Ramez Elmasri, Fabio Grandi, Christian S. Jensen, Wolfgang Käfer, Nick Kline, Krishna Kulkarni, T. Y. Cliff Leung, Nikos Lorentzos, John F. Roddick, Arie Segev, Michael D. Soo and Suryanarayana M. Sripada, Kluwer Academic Publishers, 1995, 674+xxiv pages, ISBN0-8053-2413-5, QA76.9.D3T4125.
Temporal Databases: Theory, Design, and Implementation, Abdullah Tansel, James Clifford, Shashi Gadia, Sushil Jajodia, Arie Segev, and Richard T. Snodgrass (editors), Database Systems and Applications Series, Benjamin/Cummings Pub. Co., Redwood City, CA, March 1993, 633+xx pages, ISBN0-8053-2413-5, QA76.9.D3T4125.
The Interface Description Language: Definition and Use, Richard T. Snodgrass with contributions from Karen P. Shannon, Jerry S. Kickenson, Mike A. Shapiro, Dean D. Throop, William B. Warren, David A. Lamb, John R. Nestor, and William A. Wulf, Principles of Computer Science Series, Computer Science Press, Rockville, MD, 1989, 615+xv pages.
Snodgrass has written more than 90 refereed articles in the following areas:
^Christian S. Jensen and Richard T. Snodgrass, "Temporal Data Management," IEEE Transactions on Knowledge and Data Engineering 11(1):36–44, January/February 1999.
^Richard T. Snodgrass, "Towards a Science of Temporal Databases," Keynote Address, Proceedings of the International Symposium on Temporal Representation and Reasoning, Alicante, Spain, V. Goranko and X. Sean Wang (ed), pages 6-7, June 2007.
^Paolo Terenziani and Richard T. Snodgrass, "Reconciling Point-Based and Interval-Based Semantics in Temporal Databases: A Treatment of the Telic/Atelic Distinction," IEEE Transactions on Knowledge and Data Engineering 16(5):540–551, May 2004.
^Christian S. Jensen, Richard T. Snodgrass and M. D. Soo, "Extending Existing Dependency Theory to Temporal Databases," IEEE Transactions on Knowledge and Data Engineering 8(4), August 1996, pp. 563–582.
^Curtis E. Dyreson and Richard T. Snodgrass, "Timestamp Semantics and Representation," Information Systems 18(3), September 1993, pp. 143–166.
^Suchen Hsu and Richard T. Snodgrass, "Optimal Block Size for Set-valued Attributes," Information Processing Letters 45(3), March 1993, pp. 153–158.
^Michael Böhlen, Christian S. Jensen, and Richard T. Snodgrass, "Temporal Statement Modifiers," ACM Transactions on Database Systems 25(4):407–456. December 2000.
^Curtis E. Dyreson and Richard T. Snodgrass, "Supporting Valid-time Indeterminacy," ACM Transactions on Database Systems 23(1), March 1998, pp. 1–57.
^Edward McKenzie and Richard T. Snodgrass, "An Evaluation of Relational Algebras Incorporating the Time Dimension in Databases," ACM Computing Surveys 23(4), December 1991, pp. 501–543.
^Edward McKenzie and Richard T. Snodgrass, "Schema Evolution and the Relational Algebra," Information Systems 15(2), June 1990, pp. 207–232.
^David Lomet, Richard T. Snodgrass, and Christian S. Jensen, "Using the Lock Manager to Choose Timestamps," in Proceedings of the Ninth International Database Engineering and Applications Symposium (IDEAS 2005), Montreal, Canada, July 2005.
^Dengfeng Gao, Christian S. Jensen, Richard T. Snodgrass and Michael Soo, "Join Operations in Temporal Databases," International Journal on Very Large Databases 14(1):2-29, March 2005.
^Curtis Dyreson, Richard T. Snodgrass, Faiz Currim, Sabah Currim, and Shailesh Joshi, "Weaving Temporal and Reliability Aspects into a Schema Tapestry," Data and Knowledge Engineering 63(3):726-747, 2007.
^Kyriacos E. Pavlou and Richard T. Snodgrass, "The Tiled Bitmap Forensic Analysis Algorithm," IEEE Transactions on Knowledge and Data Engineering 22(4):590-601, April 2010.
^Kyri Pavlou and Richard T. Snodgrass, "Forensic Analysis of Database Tampering," ACM Transactions on Database Systems 33(4), December, 2008, 45+26 pages.
^Richard T. Snodgrass, "A Relational Approach to Monitoring Complex Systems," ACM Transactions on Computer Systems 6(2), May 1988, pp. 157–196.