All Relations at Once: Efficient Open-World Tabular Relation Discovery with Hierarchy-Aware Reward Shaping

Xinyu Zhang, Aibo Song, Jingyi Qiu, Tianbo Zhang


Abstract
Understanding tabular semantics is essential for intelligent data management, yet data lake tables often lack explicit annotations, hindering interpretation of their structure and relations. Column Relation Extraction (RE), which identifies semantic relations between table columns, is a key step toward schema matching, data integration, and knowledge construction. Existing closed-set methods rely on predefined relation labels, while LLM-based generation offers greater flexibility but suffers from semantic ambiguity, coarse supervision, and inefficient pair-wise inference.

We propose a table-specific reinforcement learning framework for open-world RE. Instead of forcing predictions into a fixed label space, our method trains LLMs to generate free-form relations under fine-grained semantic feedback. We introduce a hierarchy-aware reward that converts semantic proximity into graded supervision, allowing the model to learn from near-miss predictions rather than treating all errors equally. We further propose relation-level policy optimization to improve efficiency: the model predicts all column-pair relations in one structured response, and each relation-level reward is assigned only to its corresponding token span. This reduces repeated table encoding and aligns optimization with relation-level correctness. Experiments demonstrate consistent improvements over strong LLM and table-specific baselines, especially on unseen relations and domains, highlighting the robustness and practicality for real-world table interpretation.
Anthology ID:
2026.emnlp-main.661
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
15234–15245
Language:
URL:
https://aclanthology.org/2026.emnlp-main.661/
DOI:
Bibkey:
Cite (ACL):
Xinyu Zhang, Aibo Song, Jingyi Qiu, and Tianbo Zhang. 2026. All Relations at Once: Efficient Open-World Tabular Relation Discovery with Hierarchy-Aware Reward Shaping. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 15234–15245, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
All Relations at Once: Efficient Open-World Tabular Relation Discovery with Hierarchy-Aware Reward Shaping (Zhang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.661.pdf