This summer school, jointly sponsored by EDBT and the INTENDED chair, was held from July 4-9, 2022. The program comprised 11 tutorials from internationally renowned researchers, covering a diverse range of topics around data and the use of knowledge (constraints, ontologies) in data management, with a special focus on inconsistent, incomplete and more generally "imperfect" data.
- Reasoning with Constraints, Andreas Pieris
- Foundations of Graph Databases, Pablo Barcelo
- Provenance, Val Tannen
- Enumeration, Nicole Schweikardt
- Probabilistic Databases, Antoine Amarilli
- Consistent Query Answering, Jef Wijsen
- Quantitative Reasoning about Constraint Violations, Benny Kimelfeld
- Ontology-Mediated Query Answering, Carsten Lutz
- Ontology-Based Data Access Made Practical, Diego Calvanese
- Computational Fact Checking, Paolo Papotti
- Data Quality, Floris Geerts
Abstracts and slides of the tutorials:summer school website
Videos of the tutorials: YouTube channel
The seminar will showcase different perspectives on handling imperfect data and knowledge and feature distinguished researchers issuing from AI, databases, and related areas.
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Speaker: Stefan Schulz, University of Graz, Austria Video Slides
Abstract: The rationale of semantic standards is to render data interoperable. This desideratum has not only been underlined by the FAIR criteria but also by the development of more principled vocabularies and information models for standardising clinical information, in particular SNOMED CT for coding all contents of the electronic health record, LOINC for the standardisation of lab parameters and other observables, and HL7-FHIR, which provides standardised contexts for embedding codes from SNOMED, LOINC and other vocabularies. The sheer size and legacy of clinical terminologies entails a series of imperfections, some of which are addressed and solved by regular updates, whereas others are inherent in the semantic standards themselves. In this talk I will exemplify three aspects that obviate clinical data interoperability when using semantic standards in practice, viz. under-specification of meaning, post-coordination and boundary conflicts. It should lead to a discussion about these interoperability problems can be avoided by better design of semantic artefacts on the one hand, and how similar or equivalent meaning can be detected by data-driven methods on the other hand.
Speaker: Sudeepa Roy, Duke University, USA Slides
Abstract: An inconsistent database violates one or more integrity constraints that are expected to hold in the database, and often needs to be repaired by deleting or updating tuples in the database. In this talk, I will describe a rule-based framework for database repair by tuple deletion that we refer to as Delta Rules. Delta rules are highly expressive and allow specifying complex, cross-relations repair logic associated with Denial Constraints, Causal Rules, and Database Triggers. We show that there are no one-size-fits-all semantics for repairs in this setting, and introduce multiple alternative semantics presenting the case for using each of them. We also study the relationships between the semantics in terms of their output and the complexity of computation. I will conclude the talk with some experimental results and related problems of interest. This is a joint work with Daniel Deutch and Amir Gilad.
Speaker: Benny Kimelfeld, Technion, Israel Video Slides
Abstract: I will discuss various computational challenges on database constraints that we have been exploring over the past years, focusing on quantitative aspects and functional dependencies. Among these are repair counting and repair minimization, which we view as different instances of inconsistency measures for databases. The need for inconsistency measurement can arise in various scenarios, including reliability estimation for datasets, progress indication in data cleaning, and the attribution of responsibility to individual tuples for the overall inconsistency. As in many fields, a conventional responsibility-sharing mechanism is the Shapley value from cooperative game theory; I will describe a systematic investigation of the complexity of this quantity under basic inconsistency measures. Finally, I will present a recent work on the problem of database repairing with soft constraints under the common interpretation that penalizes the database for every violation of every constraint, where the penalty is the cost (weight) of the constraint. A special instance of this problem is that of finding an optimal “almost matching” of a bipartite graph where a penalty is paid for every lost edge and every violation of monogamy.