# The Vadalog System: Datalog-based Reasoning for Knowledge Graphs

arXiv: https://arxiv.org/abs/1807.08709 · HTML: https://mlsanity.com/paper/1807.08709/

## Key facts

- Cited by 25 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 23 Jul 2018.

## Built on by (most cited first, 25 of 25)

- [MeTeoR: Practical Reasoning in Datalog with Metric Temporal Operators](https://mlsanity.com/paper/2201.04596/) (2022)
- [Materializing Knowledge Bases via Trigger Graphs](https://mlsanity.com/paper/2102.02753/) (2021)
- [Knowledge Graphs Querying](https://mlsanity.com/paper/2305.14485/) (2023)
- [Efficient Dependency Analysis for Rule-Based Ontologies](https://mlsanity.com/paper/2207.09669/) (2022)
- [Parallelisable Existential Rules: a Story of Pieces](https://mlsanity.com/paper/2107.06054/) (2021)
- [On the Relationship between Shy and Warded Datalog+/-](https://mlsanity.com/paper/2202.06285/) (2022)
- [Current and Future Challenges in Knowledge Representation and Reasoning](https://mlsanity.com/paper/2308.04161/) (2023)
- [Nemo: First Glimpse of a New Rule Engine](https://mlsanity.com/paper/2308.15897/) (2023)
- [Chase Anonymisation: Privacy-Preserving Knowledge Graphs with Logical Reasoning](https://mlsanity.com/paper/2410.12418/) (2024)
- [iWarded: A System for Benchmarking Datalog+/- Reasoning (technical report)](https://mlsanity.com/paper/2103.08588/) (2021)
- [Thematic recommendations on knowledge graphs using multilayer networks](https://mlsanity.com/paper/2105.05733/) (2021)
- [Harmless but Useful: Beyond Separable Equality Constraints in Datalog+/-](https://mlsanity.com/paper/2105.11147/) (2021)
- [Defeasible Reasoning via Datalog^neg](https://mlsanity.com/paper/2106.10946/) (2021)
- [Extending Sticky-Datalog+/- via Finite-Position Selection Functions: Tractability, Algorithms, and Optimization](https://mlsanity.com/paper/2108.00903/) (2021)
- [On the Complexity of Inductively Learning Guarded Rules](https://mlsanity.com/paper/2110.03624/) (2021)
- [Complexity of Arithmetic in Warded Datalog+-](https://mlsanity.com/paper/2202.05086/) (2022)
- [Chasing Streams with Existential Rules](https://mlsanity.com/paper/2205.02220/) (2022)
- [Seminaive Materialisation in DatalogMTL](https://mlsanity.com/paper/2208.07100/) (2022)
- [Swift Markov Logic for Probabilistic Reasoning on Knowledge Graphs](https://mlsanity.com/paper/2210.00283/) (2022)
- [Enhancing Datalog Reasoning with Hypertree Decompositions](https://mlsanity.com/paper/2305.06854/) (2023)
- [Ontological Reasoning over Shy and Warded Datalog+/- for Streaming-based Architectures (technical report)](https://mlsanity.com/paper/2311.12236/) (2023)
- [Optimised Storage for Datalog Reasoning](https://mlsanity.com/paper/2312.11297/) (2023)
- [Efficient Temporal Datalog Materialisation for Composite Event Recognition](https://mlsanity.com/paper/2605.02488/) (2026)
- [Stratified Negation in RDF Rules: A Correct Approach (Extended Version)](https://mlsanity.com/paper/2607.28778/) (2026)
- [Recovering Explanations from Transformed Rule-Based Ontologies](https://mlsanity.com/paper/2608.06399/) (2026)

## Abstract (arXiv)

Over the past years, there has been a resurgence of Datalog-based systems in the database community as well as in industry. In this context, it has been recognized that to handle the complex knowl-edge-based scenarios encountered today, such as reasoning over large knowledge graphs, Datalog has to be extended with features such as existential quantification. Yet, Datalog-based reasoning in the presence of existential quantification is in general undecidable. Many efforts have been made to define decidable fragments. Warded Datalog+/- is a very promising one, as it captures PTIME complexity while allowing ontological reasoning. Yet so far, no implementation of Warded Datalog+/- was available. In this paper we present the Vadalog system, a Datalog-based system for performing complex logic reasoning tasks, such as those required in advanced knowledge graphs. The Vadalog system is Oxford's contribution to the VADA research programme, a joint effort of the universities of Oxford, Manchester and Edinburgh and around 20 industrial partners. As the main contribution of this paper, we illustrate the first implementation of Warded Datalog+/-, a high-performance Datalog+/- system utilizing an aggressive termination control strategy. We also provide a comprehensive experimental evaluation.