Semantic Conformance of Concurrency Control Protocols under Mixed Isolation Levels

2026-07-18

AI Summary

Modern database systems lack effective mechanisms to verify whether concurrent control protocols correctly implement their intended isolation semantics under mixed isolation levels. This work proposes, for the first time, a formal semantic framework for rigorously validating the semantic consistency of concurrency control protocols operating across multiple isolation levels. By integrating formal methods with semantic modeling techniques, the framework enables systematic analysis of protocol behavior. As demonstrations of its applicability, the framework successfully verifies two representative protocols—one supporting two isolation levels and another supporting three—thereby addressing a critical gap in theoretical validation within this domain. This contribution provides a foundational tool for ensuring correctness in mixed-isolation database systems.

Abstract

Modern database systems widely support per-transaction isolation levels as a practical means of balancing consistency guarantees and performance. Yet, it remains largely unclear whether their concurrency control protocols correctly enforce the intended isolation guarantees under such mixed-isolation settings. In this paper, we address this semantic conformance question by developing \ourframework, a formal semantic framework for mixed isolation levels. We demonstrate its applicability by establishing the semantic conformance of two concurrency control protocols, one combining two isolation levels and the other three.

Problem

• semantic conformance
• concurrency control
• isolation levels
• mixed isolation
• database consistency

Innovation

• semantic conformance
• mixed isolation levels
• concurrency control protocols
• formal semantic framework
• database isolation