Benchmarking and Improving Text-to-SQL Generation under Ambiguity

Adithya Bhaskar, Tushar Tomar, Ashutosh Sathe, Sunita Sarawagi


Abstract
Research in Text-to-SQL conversion has been largely benchmarked against datasets where each text query corresponds to one correct SQL. However, natural language queries over real-life databases frequently involve significant ambiguity about the intended SQL due to overlapping schema names and multiple confusing relationship paths. To bridge this gap, we develop a novel benchmark called AmbiQT with over 3000 examples where each text is interpretable as two plausible SQLs due to lexical and/or structural ambiguity. When faced with ambiguity, an ideal top-k decoder should generate all valid interpretations for possible disambiguation by the user. We evaluate several Text-to-SQL systems and decoding algorithms, including those employing state-of-the-art LLMs, and find them to be far from this ideal. The primary reason is that the prevalent beam search algorithm and its variants, treat SQL queries as a string and produce unhelpful token-level diversity in the top-k. We propose LogicalBeam, a new decoding algorithm that navigates the SQL logic space using a blend of plan-based template generation and constrained infilling. Counterfactually generated plans diversify templates while in-filling with a beam-search that branches solely on schema names provides value diversity. LogicalBeam is up to 2.5 times more effective than state-of-the-art models at generating all candidate SQLs in the top-k ranked outputs. It also enhances the top-5 Exact and Execution Match Accuracies on SPIDER and Kaggle DBQA.
Anthology ID:
2023.emnlp-main.436
Volume:
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2023
Address:
Singapore
Editors:
Houda Bouamor, Juan Pino, Kalika Bali
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
7053–7074
Language:
URL:
https://aclanthology.org/2023.emnlp-main.436
DOI:
10.18653/v1/2023.emnlp-main.436
Bibkey:
Cite (ACL):
Adithya Bhaskar, Tushar Tomar, Ashutosh Sathe, and Sunita Sarawagi. 2023. Benchmarking and Improving Text-to-SQL Generation under Ambiguity. In Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing, pages 7053–7074, Singapore. Association for Computational Linguistics.
Cite (Informal):
Benchmarking and Improving Text-to-SQL Generation under Ambiguity (Bhaskar et al., EMNLP 2023)
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