# Ronald Fagin

Ronald Fagin | |
---|---|

Ronald Fagin | |

Born | 1945^{[1]}Oklahoma City, OK, USA |

Residence | Los Gatos, California |

Nationality | American |

Alma mater | Dartmouth College, University of California, Berkeley |

Known for | Fagin's theorem |

Awards | Gödel prize (2014), W. Wallace McDowell Award (2012), SIGMOD Edgar F. Codd Innovations Award (2004) |

Scientific career | |

Fields | Logic in Computer Science, Database theory, Finite model theory, Rank and score aggregation, Reasoning about knowledge |

Institutions | IBM Almaden Research Center |

Doctoral advisor | Robert Lawson Vaught |

**Ronald Fagin** (born 1945) is an American mathematician and computer scientist, and IBM Fellow at the IBM Almaden Research Center. He is known for his work in database theory, finite model theory, and reasoning about knowledge.^{[2]}

## Contents

## Biography[edit]

Ron Fagin was born and grew up in Oklahoma City, where he attended Northwest Classen High School. Following that, he completed his undergraduate degree at Dartmouth College. Fagin received his Ph.D. in Mathematics from the University of California, Berkeley in 1973, where he worked under the supervision of Robert Vaught.

He joined the IBM Research Division in 1973, spending two years at the Thomas J. Watson Research Center, and then transferred in 1975 to what is now the IBM Almaden Research Center in San Jose, California.

He has served as program committee chair for ACM Symposium on Principles of Database Systems 1984,^{[3]} Theoretical Aspects of Reasoning about Knowledge 1994,^{[4]} ACM Symposium on Theory of Computing 2005,^{[5]} and the International Conference on Database Theory 2009.^{[6]}

Fagin has received numerous professional awards for his work. He was elected Member of the National Academy of Engineering, American Academy of Arts and Sciences, IBM Fellow, ACM Fellow, IEEE Fellow, and Fellow of the American Association for the Advancement of Science. He won the 2014 Gödel Prize and he received a Docteur Honoris Causa from the University of Paris. The IEEE granted him the IEEE W. Wallace McDowell Award and the IEEE Technical Achievement Award;^{[7]} the ACM granted him the ACM SIGMOD Edgar F. Codd Innovations Award^{[8]} and IBM granted him eight IBM Outstanding Innovation Awards, two IBM supplemental Patent Issue Awards, given for key IBM patents, the IBM Outstanding Technical Achievement Award, and two IBM Corporate Awards. Fagin is listed among the "Highly Cited Researchers."^{[9]} He won Best Paper awards at the 1985 International Joint Conference on Artificial Intelligence, the 2001 ACM Symposium on Principles of Database Systems, the 2010 International Conference on Database Theory, and the 2015 International Conference on Database Theory. He won 10-year Test-of-Time Awards at the 2011 ACM Symposium on Principles of Database Systems, the 2013 International Conference on Database Theory, and the 2014 ACM Symposium on Principles of Database Systems.

## Work[edit]

### Fagin's theorem[edit]

Fagin's theorem, which he proved in his PhD thesis, states that existential second-order logic coincides with the complexity class NP in the sense that a decision problem can be expressed in existential second-order logic if and only if it can be solved by a non-deterministic Turing machine in polynomial time. This work helped found the area of finite model theory.^{[10]}

### Other contributions[edit]

Another result that he proved in his PhD thesis is that first-order logic has a zero-one law, a tool for proving inexpressibility results for database query languages.^{[11]} This result was proved independently by Glebskiĭ et al. earlier (1969) in Russia,^{[12]} with a very different proof.

He is also known for his work on higher Normal Forms in Database Theory, particularly 4NF.

Besides Fagin's Theorem, other concepts named after Fagin are "Fagin's algorithm" for score aggregation,^{[13]} the "Fagin-inverse" for data exchange,^{[14]} and "Fagin games" ^{[15]} and "Ajtai Fagin games" ^{[16]} for proving inexpressibility results in logic.

## Publications[edit]

Fagin has authored or co-authored numerous articles,^{[17]}^{[18]} and a book:

- Fagin, Ronald, Joseph Y. Halpern, Yoram Moses, and Moshe Y. Vardi. Reasoning about knowledge. MIT press (1995). Paperback edition (2003).

Articles, a selection:

- Fagin, Ronald. "Generalized first-order spectra and polynomial-time recognizable sets". Complexity of Computation, ed. R. Karp, SIAM-AMS Proceedings, Vol. Vol. 7 (1974):43-73.
- Fagin, Ronald, Jurg Nievergelt, Nicholas J. Pippenger, and H. Raymond Strong. "Extendible hashing—a fast access method for dynamic files." ACM Transactions on Database Systems (TODS) 4.3 (1979): 315-344.
- Fagin, Ronald, Amnon Lotem, and Moni Naor. "Optimal aggregation algorithms for middleware." Journal of Computer and System Sciences 66 (2003): 614-656. (Special issue for selected papers from the 2001 ACM Symposium on Principles of Database Systems).
- Fagin, Ronald, Phokion Kolaitis, Renee J Miller, and Lucian Popa. Data exchange: semantics and query answering, Theoretical Computer Science 336 (2005): 89-124. (Special issue for selected papers from the 2003 International Conference on Database Theory).

## References[edit]

**^***American Men and Women of Science*, Thomson Gale, 2004.**^**Reasoning about Knowledge. Co-authors J.Y. Halpern, Y. Moses and M.Y. Vardi. Published by MIT Press, 1995. Paperback edition, 2003.**^**ACM Symposium on Principles of Database Systems 1984**^**Theoretical Aspects of Reasoning about Knowledge 1994**^**Symposium on Theory of Computing 2005**^**International Conference on Database Theory 2009**^**IEEE Technical Achievement Award**^**ACM SIGMOD Edgar F. Codd Innovations Award**^**Institute for Scientific Information Highly Cited Researchers**^**Neil Immerman, Descriptive Complexity. Springer-Verlag, 1999**^**Ronald Fagin: "Probabilities on Finite Models". Journal of Symbolic Logic, 41(1):50-58, 1976**^**Y.V. Glebskiĭ, D.I. Kogan, M.I. Liogonkiĭ, and V.A. Talanov: "Range and degree of realizability of formulas in the restricted predicate calculus." Kibernetika, 2:17-28, 1969**^**Fagin, Ronald. "Combining fuzzy information from multiple systems." Journal of Computer and System Sciences 58 (1999): 83-99. (Special issue for selected papers from the 1996 ACM Symposium on Principles of Database Systems).**^**Fagin, Ronald, "Inverting schema mappings". ACM Trans. on Database Systems 32, 4, Nov. 2007. (Special issue for selected papers from the 2006 ACM Symposium on Principles of Database Systems.)**^**Fagin, Ronald, "Monadic generalized spectra". Zeitschr. f. math. Logik und Grundlagen d. Math. 21, 1975, pp. 89-96.**^**Ajtai, Miklos and Fagin, Ronald, "Reachability is harder for directed than for undirected finite graphs". Journal of Symbolic Logic 55, 1, March 1990, pp. 113-150. Preliminary version appeared in Proc. 29th IEEE Symposium on Foundations of Computer Science, 1988, pp. 358-367.**^**Ronald Fagin: IBM Almaden Research Center Google Scholar profile**^**Ronald Fagin The DBLP Computer Science Bibliography

## External links[edit]

- 1945 births
- Living people
- American computer scientists
- Database researchers
- IBM employees
- IBM Fellows
- IBM Research computer scientists
- People from Oklahoma City
- Northwest Classen High School alumni
- Dartmouth College alumni
- University of California, Berkeley alumni
- Fellows of the Association for Computing Machinery
- Fellow Members of the IEEE
- Fellows of the American Association for the Advancement of Science
- Gödel Prize laureates