The 2020 Alonzo Church Award

The ACM Special Interest Group on Logic (SIGLOG), the European Association for Theoretical Computer Science (EATCS), the European Association for Computer Science Logic (EACSL), and the Kurt Goedel Society (KGS) are pleased to announce that

Ronald Fagin, Phokion G. Kolaitis, Renée J. Miller, Lucian Popa, and Wang Chiew Tan

have been selected as the winners of the 2020 Alonzo Church Award for Outstanding Contributions to Logic and Computation.

The award recognizes their ground-breaking work on laying the logical foundations for data exchange, described in the following papers:

(1) Ronald Fagin, Phokion G. Kolaitis, Lucian Popa, Renée J. Miller. Data exchange: Semantics and Query Answering, Proceedings of the 9th International Conference on Database Theory (ICDT 2003), pp. 207-223, 2003.
Full journal  version: Theoretical Computer Science, Vol. 336, No. 1, pp. 89-124, 2005.

(2) Ronald Fagin, Phokion G. Kolaitis, Lucian Popa, Wang Chiew Tan. Composing Schema Mappings: Second-Order Dependencies to the Rescue, Proceedings of the 23rd ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems (PODS 2004), pp. 83-94, 2004.
Full journal version: ACM Transactions on Database Systems, Vol. 30, No. 4, pp. 994-1055, 2005.

Data exchange is the problem of transforming data structured under a schema, called the source schema, into data conforming to a different schema, called the target schema. The results and techniques developed have in addition to gaining theoretical insights influenced the development of industrial and academic tools. The 2020 Church Award was selected by a panel consisting of Mariangiola Dezani, Thomas Eiter (chair), Javier Esparza, Radha Jagadeesan and Natarajan Shankar.


Data exchange is an old and ubiquitous problem in data management that was described by Philip Bernstein as the ìoldest problem in databasesî. Early work on data exchange used low-level, ad hoc programs to transform data from the source schema to the target schema, which resulted into inefficiencies and limited reusability. Publications (1) and (2) laid the logical foundations for data exchange and became the catalyst for the development of data exchange as a research area in its own right. Publication (1) is about logic in computer science: a fragment of first-order logic, called source-to-target tuple-generating dependencies (in short, s-t tgds), is systematically used as a specification language in data exchange. The algorithmic and structural properties of s-t tgds are explored, and the concept of a universal solution is introduced as the preferred way to carry out the data exchange task. Publication (2) is about logic from computer science: first, it is shown that the language of s-t tgds is not closed under composition; second, a new fragment of second-order logic, called second-order tuple-generating dependencies (in short, SO tgds) is identified and shown to be the ìrightî logic-based specification language for composing s-t tgds. The award publications are well-cited and have been recognized with two test-of-time awards. your social media marketing partner
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