Knowledge Base Construction for Knowledge-Augmented Text-to-SQL
Jinheon Baek, Horst Samulowitz, Oktie Hassanzadeh, Dharmashankar Subramanian, Sola Shirai, Alfio Gliozzo, Debarun Bhattacharjya
TL;DR
This paper introduces KAT-SQL, a knowledge-base–driven framework for text-to-SQL that constructs a comprehensive repository of domain- and schema-relevant knowledge and retrieves it to augment SQL generation. The knowledge base is built from existing samples and database schemas and expanded automatically via LLMs with context-rich prompts and carefully selected few-shot examples, then leveraged through embedding-based retrieval and query-conditioned refinement. Across BIRD, Spider, and CSTINSIGHT datasets and multiple database overlap scenarios, KAT-SQL consistently outperforms knowledge-augmented baselines and approaches oracle-level knowledge, demonstrating strong gains in execution accuracy and efficiency. The work also shows that the knowledge base generalizes to unseen domains, maintains robustness across different LLMs, and remains efficient in real-time usage, underscoring its practical impact for scalable, knowledge-grounded text-to-SQL systems.
Abstract
Text-to-SQL aims to translate natural language queries into SQL statements, which is practical as it enables anyone to easily retrieve the desired information from databases. Recently, many existing approaches tackle this problem with Large Language Models (LLMs), leveraging their strong capability in understanding user queries and generating corresponding SQL code. Yet, the parametric knowledge in LLMs might be limited to covering all the diverse and domain-specific queries that require grounding in various database schemas, which makes generated SQLs less accurate oftentimes. To tackle this, we propose constructing the knowledge base for text-to-SQL, a foundational source of knowledge, from which we retrieve and generate the necessary knowledge for given queries. In particular, unlike existing approaches that either manually annotate knowledge or generate only a few pieces of knowledge for each query, our knowledge base is comprehensive, which is constructed based on a combination of all the available questions and their associated database schemas along with their relevant knowledge, and can be reused for unseen databases from different datasets and domains. We validate our approach on multiple text-to-SQL datasets, considering both the overlapping and non-overlapping database scenarios, where it outperforms relevant baselines substantially.
