Conjunctive Queries: Unique Characterizations and Exact Learnability

Autor: ten Cate, B., Dalmau, V., Yi, K., Wei, Z.
Přispěvatelé: ILLC (FNWI), Logic and Computation (ILLC, FNWI/FGw)
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: ACM Transactions on Database Systems, 47(4):14. Association for Computing Machinery (ACM)
24th International Conference on Database Theory: ICDT 2021, March 23-26, 2021, Nicosia, Cyprus
24th International Conference on Database Theory
ISSN: 1557-4644
0362-5915
DOI: 10.1145/3559756
Popis: We answer the question of which conjunctive queries are uniquely characterized by polynomially many positive and negative examples, and how to construct such examples efficiently. As a consequence, we obtain a new efficient exact learning algorithm for a class of conjunctive queries. At the core of our contributions lie two new polynomial-time algorithms for constructing frontiers in the homomorphism lattice of finite structures. We also discuss implications for the unique characterizability and learnability of schema mappings and of description logic concepts.
LIPIcs, Vol. 186, 24th International Conference on Database Theory (ICDT 2021), pages 9:1-9:24
Databáze: OpenAIRE