MySQL or PostgreSQL: how would you choose for a new project?

Summary

Both are mature and handle most OLTP workloads well. PostgreSQL offers richer SQL and types (JSONB with GIN indexes, arrays, partial and expression indexes, extensions such as PostGIS and pgvector, transactional DDL). MySQL is simple to operate, very well understood at web scale, and has strong replication tooling and managed offerings. Team experience and ecosystem often decide.

Longer Answer

Lean to PostgreSQL for complex queries and analytics, rich data types, geospatial, strict standards behaviour, or many extensions. Lean to MySQL when the team and tooling are MySQL-centric, for very read-heavy web workloads with familiar replication, or for compatibility with existing systems (Vitess for sharding).

Operational differences matter: PostgreSQL needs VACUUM tuning and uses a process per connection (pooling with PgBouncer is common); MySQL's clustered primary key makes PK choice more critical.

Key Points

• Both are excellent for OLTP.
• PostgreSQL: richer SQL, types, extensions.
• MySQL: operational simplicity, ecosystem.
• Team experience often decides.

What interviewers look for

A balanced comparison with concrete differences, not tribal preference.