# Abstractions of Queries in Ontology-Based Data Access

arXiv: https://arxiv.org/abs/2606.24618 · HTML: https://mlsanity.com/paper/2606.24618/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 3 of its 23 references that are in the map.
- First posted on arXiv 23 Jun 2026.

## Builds on (most cited first, 3 of 3)

- [Sound, Complete and Minimal UCQ-Rewriting for Existential Rules](https://mlsanity.com/paper/1311.3198/) (2013)
- [Query Expressibility and Verification in Ontology-Based Data Access](https://mlsanity.com/paper/2011.09176/) (2020)
- [Query Rewriting with Disjunctive Existential Rules and Mappings](https://mlsanity.com/paper/2306.05973/) (2023)

## Abstract (arXiv)

In ontology-based data access (OBDA), multiple data sources are integrated via mappings to an ontology. We consider an OBDA setting based on existential rules and the certain answer semantics. We address the recent issue of query abstraction, which consists of abstracting data queries by translating them to the ontology layer. Since a perfect abstraction may not exist, the notions of minimally complete and maximally sound abstractions have been introduced. We study abstractions within an extension of UCQs with a limited form of inequality and a special predicate marking database constants. While this extension does not lead to an increased complexity of the problems of interest, it is able to express minimally complete abstractions, hence perfect abstractions when they exist. We also characterize maximally sound abstractions by making a new connection with the notion of maximum recovery stemming from data exchange.