BASS: Budget-Aware Structured Search for Text-to-SQL Generation

Bin Zheng, Zheng Chen, Kefan Chen, Lulu Cui, Hao Tang, Zijun Xu, Chen Anlong


Abstract
Text-to-SQL generation remains challenging for small and medium-sized language models, which must produce queries that are structurally valid, schema-grounded, and semantically faithful under limited inference budgets. Naive test-time scaling strategies, such as repeated sampling or unconstrained search, often spend budget on invalid, redundant, or semantically weak candidates. We present BASS, a Budget-Aware Structured Search framework for Text-to-SQL generation. BASS searches over deterministic SQL semantic units produced by rule-based Structural Boundary Detection, with lightweight admissibility filtering to reject malformed units. It scores completed candidates using an execution-gated rubric verifier: non-executable SQL receives zero reward, while executable SQL is assigned a continuous semantic score based on schema grounding, intent matching, predicate correctness, aggregation and ordering, and join/compositional structure. To improve budget usage, BASS introduces stagnation-aware branch suppression and exhaustion-aware early stopping, reallocating computation away from saturated search regions. Experiments on Spider and BIRD show strong zero-shot performance across Qwen2.5-Coder backbones. Controlled analyses further show that BASS uses fixed maximum rollout budgets adaptively, achieves better quality–cost behavior than naive repeated sampling, and benefits from semantic verification and stagnation-aware budget control.
Anthology ID:
2026.findings-emnlp.1025
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
21659–21686
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URL:
https://aclanthology.org/2026.findings-emnlp.1025/
DOI:
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Cite (ACL):
Bin Zheng, Zheng Chen, Kefan Chen, Lulu Cui, Hao Tang, Zijun Xu, and Chen Anlong. 2026. BASS: Budget-Aware Structured Search for Text-to-SQL Generation. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 21659–21686, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
BASS: Budget-Aware Structured Search for Text-to-SQL Generation (Zheng et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1025.pdf