MVCC Concept: The No-Lock Approach for High-Concurrency Systems

In high-concurrency systems, traditional locking mechanisms often become performance bottlenecks. MVCC (Multi-Version Concurrency Control) provides a way to minimize locks or avoid them entirely. By using a “versioning + snapshot” approach, MVCC allows high-concurrency access while ensuring transaction isolation and data consistency. This article explains MVCC from its principles, essence, design philosophy, and practical insights for developers, so you can not only understand it but also apply its ideas in high-concurrency system design. 1. What is MVCC MVCC (Multi-Version Concurrency Control) is a concurrency control mechanism with the core idea: Instead of directly overwriting existing data, each write operation creates a new version. Each transaction works with its own snapshot of the data and determines which versions are visible based on version IDs, allowing reads and writes to proceed without blocking each other. In MySQL InnoDB, MVCC supports: Snapshot Read: Reads historical v