PostgreSQL vs MySQL: Which SQL Database?
PostgreSQL is a feature-rich, standards-oriented relational database; MySQL is a fast, ubiquitous database favored for read-heavy web workloads.
PostgreSQL emphasizes correctness, advanced types (JSONB, arrays, ranges), window functions, CTEs, and extensibility, making it strong for complex queries and analytical work. MySQL (and its forks) is extremely widely deployed, simple to operate, and well tuned for read-heavy web apps. Both are mature and ACID-compliant; the choice often comes down to feature needs and existing ecosystem.
| PostgreSQL | MySQL | |
|---|---|---|
| SQL features | Rich (CTEs, windows, JSONB) | Solid, fewer extras |
| Extensibility | High (extensions, types) | Moderate |
| Read-heavy web | Strong | Very strong |
| Replication | Logical + streaming | Mature, simple |
| Best for | Complex queries, correctness | Common web stacks |
Use case and ecosystem
Postgres suits applications with complex queries, JSON workloads, geospatial (PostGIS), or strict correctness needs. MySQL suits classic LAMP-style web apps, content sites, and teams already standardized on it. Both have huge ecosystems and managed offerings on every cloud.
In CI
Both run as service containers for integration tests; pin the image version and wait for readiness before running migrations. Either works well on managed runners, where faster runners cut database container startup and test time.
The verdict
Want advanced SQL, JSONB, extensions, and strict correctness: PostgreSQL. Want a ubiquitous, simple, read-optimized database with a vast hosting ecosystem: MySQL. Greenfield projects increasingly default to Postgres; MySQL remains a safe choice for conventional web stacks.