2026-07-20T05:27:53Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:19792 2024-03-14T08:42:35Z ddc:004 open_access

Right-Adjoints for Datalog Programs ten Cate, Balder Dalmau, Víctor Opršal, Jakub Datalog Adjoints Homomorphism Dualities Database Constraints Conjunctive Queries Data Examples A Datalog program can be viewed as a syntactic specification of a mapping from database instances over some schema to database instances over another schema. We establish a large class of Datalog programs for which this mapping admits a (generalized) right-adjoint. We employ these results to obtain new insights into the existence of, and methods for constructing, homomorphism dualities within restricted classes of instances. From this, we derive new results regarding the existence of uniquely characterizing data examples for database queries in the presence of integrity constraints. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Balder ten Cate and Víctor Dalmau and Jakub Opršal 2024 Is Part Of LIPIcs, Volume 290, 27th International Conference on Database Theory (ICDT 2024) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.ICDT.2024.10 urn:nbn:de:0030-drops-197929 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICDT.2024.10 eng https://creativecommons.org/licenses/by/4.0/legalcode