PostgreSQL vs MySQL: A 2026 Production Decision Framework

Picking a database for a new service in 2026 is less about "features" and more about what fails first in production: write concurrency, query shape drift, operational ergonomics, and how painful the first schema evolution will be. This framework treats PostgreSQL vs MySQL as an operator decision: score your workload, look for tipping points, then validate with concrete EXPLAIN patterns and early-life metrics. Production-First Decision Rubric Start by treating the database choice like capacity planning: define the dominant workload, then pick the engine that degrades more gracefully when your assumptions are wrong. When Either Is Fine If you have a classic OLTP service (orders, users, subscriptions), moderate concurrency, and you keep JSON usage light, both PostgreSQL and MySQL will work. The decision is usually driven by team familiarity, managed service maturity in your cloud, and ecosystem. Tipping Points (Hard Decision Triggers) JSON is part of your query API (filtering, containment