Multiversion Concurrency Control

Introduction

Multiversion concurrency control (MVCC) is a concurrency control technique that allows multiple versions of the same record to exist simultaneously during a given time and provides a consistent view of the database at a point in the past identified by the timestamp.

With this method, every active transaction in the database sees a snapshot of the data at that point. The new transactions won’t see any changes made by other transactions until the database commits the transaction.

In addition, multiversion concurrency control techniques prevent nonrepeatable reads problems.

Implementation

When a database transaction starts, the database generates a unique, monotonically increasing ...