How Does PostgreSQL Use MVCC and Locks in Read Committed?

In this video, we explore how PostgreSQL handles concurrency using MVCC (Multi-Version Concurrency Control) and locks. We focus on the Read Committed isolation level and understand how Postgres prevents dirty reads while still allowing high concurrency. Through practical demos, we cover: How PostgreSQL maintains multiple row versions Why dirty reads are prevented When and why updates get blocked due to locks We also visualize everything step-by-step: xmin and xmax explained Transaction snapshots How visibility rules work internally Topics covered: MVCC (Multi-Version Concurrency Control) Read Committed isolation level Row versioning in PostgreSQL Locking behavior in updates xmin, xmax, and snapshots Timestamps: 00:11 MVCC Demo 1 02:17 Lock Demo 2 04:18 Understand via Blackboard This video is ideal for: Backend developers, database enthusiasts, and anyone preparing for system design or database interviews. #PostgreSQL #MVCC #DatabaseInternals #DBMS #SystemDesign #ConcurrencyControl