Mechanizing Transactional Anomalous Patterns for Weak Isolation Levels

2026-10-05

AI Summary

This study addresses the reliance on manual proofs and the absence of machine verification for Transactional Anomaly Patterns (TAPs) under weak isolation levels. Leveraging the Rocq proof assistant, this work presents the first complete formal modeling and machine-verified proofs of TAPs and their characterization theorems. During this process, two critical definitional flaws in the original theoretical history model were identified and rectified. Ultimately, this project establishes a comprehensive machine-verified framework and integrates the corrected formal definitions into the Plume weak isolation checker. By providing a rigorous formal foundation, this research significantly enhances correctness guarantees for database systems operating under weak isolation levels.

Abstract

Recently proposed transactional anomalous patterns (TAPs) provide a semantic characterization of weak isolation levels and serve as the foundation for TAP-based isolation checking. Yet, these characterizations currently exist only as pen-and-paper proofs. We present the first machine-checked formalization of TAPs and their associated weak isolation levels in Rocq. We further establish machine-checked proofs of the corresponding TAP-based characterization theorems. The mechanization process revealed two subtle issues in the original presentation: an underspecified transaction history model and an incomplete TAP characterization of the Read Atomicity isolation level that failed to capture violations of session guarantees. We address these issues by refining the definition of transaction histories and the corresponding TAP definitions, and re-establish all characterization theorems in Rocq. These refinements have further been integrated into the weak isolation checker Plume.

Problem

• Transactional Anomalous Patterns
• Weak Isolation Levels
• Mechanized Formalization
• Read Atomicity

Innovation

• Mechanized Formalization
• Transactional Anomalous Patterns
• Weak Isolation Levels
• Rocq
• Isolation Checking