MySQL vs PostgreSQL comparison for web developers — performance, JSON support, full-text search, replication, licensing, and which database to choose for your project.
Here's a quick overview of how PostgreSQL and MySQL stack up across the most important decision criteria:
| Category | PostgreSQL | MySQL |
|---|---|---|
| JSON Support | Native JSONB with indexing | Basic JSON functions |
| SQL Compliance | More standards-compliant | Some quirks from history |
| Full-Text Search | Good | Faster for simple FTS |
| Replication | Logical + streaming | More mature replication options |
| Performance | Better for complex queries | Faster for simple reads (some cases) |
| Extensions | PostGIS, pgvector, TimescaleDB, etc. | Fewer extensions |
| License | PostgreSQL (very permissive) | GPL / Commercial (Oracle) |
| Cloud Support | Every major cloud | Every major cloud |
| WordPress | Not typical | WordPress default |
| Window Functions | Full support | Limited until 8.0 |
| Connection Pooling | pgBouncer | ProxySQL |
| ORM Support | All major ORMs | All major ORMs |
Based on real-world usage, community feedback, and benchmark data, here's how each scores across key dimensions (out of 100):
For modern web applications that need to store semi-structured data, PostgreSQL's JSONB type is a significant advantage. JSONB is stored in a binary format that supports full indexing:
-- PostgreSQL JSONB with index
CREATE TABLE products (
id SERIAL PRIMARY KEY,
metadata JSONB
);
CREATE INDEX ON products USING GIN (metadata);
-- Query JSON fields efficiently
SELECT * FROM products
WHERE metadata @> '{"category": "electronics"}';
-- Update nested JSON
UPDATE products
SET metadata = metadata || '{"featured": true}'
WHERE id = 42;
MySQL's JSON support has improved in version 8.0 but still lacks the indexing flexibility and operator richness of PostgreSQL's JSONB.
One of the most important developments in 2023-2024 is pgvector, a PostgreSQL extension that adds vector similarity search. This is what enables semantic search, recommendation systems, and RAG (Retrieval-Augmented Generation) patterns for AI applications.
-- Install pgvector extension
CREATE EXTENSION vector;
-- Store embeddings
CREATE TABLE documents (
id SERIAL PRIMARY KEY,
content TEXT,
embedding vector(1536) -- OpenAI ada-002 dimensions
);
-- Nearest-neighbor search
SELECT content, embedding <-> $1 AS distance
FROM documents
ORDER BY distance
LIMIT 5;
MySQL has no equivalent. If you're building any AI-powered features, PostgreSQL + pgvector is a strong reason to choose it.
Both Supabase and Neon (popular PostgreSQL cloud providers) include pgvector by default, making it trivially easy to add vector search to your PostgreSQL application.