Content
PostgreSQL vs MySQL in 2026
Two threads went viral on r/PostgreSQL recently. One: "$480K/year saved by switching from MySQL to Postgres" (51 upvotes). The other: "You just need Postgres" (264 upvotes).
The $480K Cost Angle
MySQL Enterprise Edition costs thousands per server per year
Amazon RDS for MySQL charges a premium for Multi-AZ
PostgreSQL is fully open source under the PostgreSQL License
Managed PostgreSQL (Supabase, Neon, Railway) has aggressively competitive pricing
Performance Comparison
Read-Heavy OLTP
MySQL has a slight edge in simple, high-concurrency reads. This advantage has narrowed.
Write-Heavy and Mixed
PostgreSQL's MVCC handles write-heavy workloads with fewer lock contention issues.
Complex Queries
PostgreSQL's query planner is more sophisticated. Lateral joins, recursive CTEs, and partial indexes.
Feature Comparison Table
Feature | PostgreSQL | MySQL |
|---|---|---|
JSON support | JSONB (binary, indexed) | JSON (text-based) |
Window functions | Full support, mature | Since 8.0, less optimized |
CTEs | Full recursive, materialization control | Since 8.0, no CYCLE/SEARCH |
Full-text search | Built-in tsvector, ranking | FULLTEXT index, basic |
Extensions | PostGIS, pgvector, TimescaleDB | Limited |
Licensing | PostgreSQL License (permissive) | GPL / Commercial |
When MySQL Is Still Right
Already on PlanetScale
ORM or framework is MySQL-optimized
Maximum simple read throughput
Team's DBA expertise is MySQL-centric
Migration: What the Real Work Looks Like
Schema conversion: TINYINT(1) to BOOLEAN, AUTO_INCREMENT to SERIAL
SQL dialect: GROUP_CONCAT to STRING_AGG, LIMIT x,y to LIMIT y OFFSET x
Application layer: ORM config, raw SQL review
AI2SQL supports both PostgreSQL and MySQL dialects for easy switching.
pgvector Changes the Calculation
AI-native applications need vector storage. PostgreSQL has pgvector. MySQL has no equivalent. Teams building AI features choose PostgreSQL by default.
Verdict
New projects: PostgreSQL. Existing MySQL: evaluate if you are on Enterprise licensing or need JSON/vector. For analytics: PostgreSQL wins clearly.
AI2SQL generates dialect-aware SQL for both databases.
