In progress

Concurrency Control: How PostgreSQL and MongoDB Handle Simultaneous Writers

Concurrency control is where database theory meets production reality. This article goes deep into how PostgreSQL and MongoDB handle simultaneous readers and writers — the full MVCC mechanism, every lock type, how contention manifests, and the systematic approach to diagnosing and resolving it before it becomes an incident.

This post is still being written. The title and outline are published so you can follow along with the series — the full article will replace this page when it ships.