Learning to Retrieve: Dual-Level Long-Term Memory for Text-to-SQL Agents

Yibo Wang, Nikki Lijing Kuang, Philip S. Yu, Zhewei Yao, Yuxiong He


Abstract
Interactive text-to-SQL agents solve database tasks through multi-turn interactions involving schema exploration, query execution, feedback interpretation, and decision revision. Long-term memory helps agents reuse past experiences, but existing retrieval methods remain limited. Static methods use fixed similarity heuristics, whereas dynamic methods often learn from sparse terminal outcomes and retrieve at a single decision horizon. This is insufficient when memory usefulness changes across interaction stages, since memories useful for initial planning may differ from those needed for local, state-conditioned execution. We propose MERIT, a dynamic multi-horizon memory retrieval framework. MERIT maintains episode-level memory for global strategic guidance and turn-level memory for local decision support. Both levels use learned retrieval policies optimized with reinforcement learning. To train turn-level retrieval despite limited intermediate supervision, MERIT uses a lightweight Process Reward Model to provide dense proxy rewards for local memory selection. On BIRD-Interact, MERIT achieves higher success rates and fewer interaction turns than no-memory, static-retrieval, and dynamic-retrieval baselines. Transfer results on Spider2-Snow further show that the learned policies transfer without degradation, staying above all memory baselines without benchmark-specific tuning. These results suggest that multi-horizon retrieval improves experience reuse in interactive text-to-SQL agents. Our code is available at https://github.com/YiboWANG214/MERIT.
Anthology ID:
2026.emnlp-main.1986
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:
45174–45197
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1986/
DOI:
Bibkey:
Cite (ACL):
Yibo Wang, Nikki Lijing Kuang, Philip S. Yu, Zhewei Yao, and Yuxiong He. 2026. Learning to Retrieve: Dual-Level Long-Term Memory for Text-to-SQL Agents. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 45174–45197, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Learning to Retrieve: Dual-Level Long-Term Memory for Text-to-SQL Agents (Wang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1986.pdf