Castle: Causal Cascade Updates in Relational Databases with Large Language Models
Yongye Su, Yucheng Zhang, Zeru Shi, Bruno Ribeiro, Elisa Bertino
TL;DR
Castle addresses cascading updates in denormalized relational databases by enabling schema-only, LLM-assisted generation of UPDATE statements with causal propagation. It introduces a multi-stage framework that identifies direct and cascade targets, plans evidence-grounded subqueries, and generates triggers to maintain derived metrics, all without exposing table data. The approach is evaluated on Soccer Transfer and UCI Online Retail II datasets, achieving up to 85% correctness and outperforming baselines while preserving data confidentiality. The work demonstrates practical implications for privacy-preserving, real-time maintenance of complex relational schemas in modern DBMSs.
Abstract
This work introduces Castle, the first framework for schema-only cascade update generation using large language models (LLMs). Despite recent advances in LLMs for Text2SQL code generation, existing approaches focus primarily on SELECT queries, neglecting the challenges of SQL update operations and their ripple effects. Traditional CASCADE UPDATE constraints are static and unsuitable for modern, denormalized databases, which demand dynamic, context-aware updates. Castle enables natural language instructions to trigger multi-column, causally consistent SQL UPDATE statements, without revealing table content to the model. By framing UPDATE SQL generation as a divide-and-conquer task with LLMs' reasoning capacity, Castle can determine not only which columns must be directly updated, but also how those updates propagate through the schema, causing cascading updates -- all via nested queries and substructures that ensure data confidentiality. We evaluate it on real-world causal update scenarios, demonstrating its ability to produce accurate SQL updates, and thereby highlighting the reasoning ability of LLMs in automated DBMS.
