Choosing between PostgreSQL and MySQL is one of the most consequential decisions in backend development. Both are open-source, mature, and battle-tested relational databases — but they have fundamentally different philosophies, feature sets, and performance characteristics. This guide helps you make the right choice in 2026.
Quick Overview
PostgreSQL (often called Postgres) prioritizes standards compliance, data integrity, and extensibility. MySQL prioritizes simplicity, speed for read-heavy workloads, and ease of use. Both power some of the largest applications in the world.
Feature PostgreSQL MySQL 8.x
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License PostgreSQL (free) GPL / Commercial
ACID Compliance Full Full (InnoDB)
JSON Support JSONB (excellent) JSON (good)
Full-Text Search Built-in tsvector FULLTEXT index
Replication Streaming + Logical Binary log + GTID
Max DB Size Unlimited 256TB
Partitioning Declarative RANGE/LIST/HASH
Window Functions Full support Partial (8.x+)
Extensions Rich ecosystem Plugins (fewer)
Default in Cloud Supabase, RDS PlanetScale, RDSFeature Comparison
PostgreSQL has historically had a much richer feature set. MySQL has closed the gap significantly with version 8.x, but PostgreSQL still leads in advanced SQL features.
-- Feature Comparison: PostgreSQL vs MySQL
-- 1. JSON Support
-- PostgreSQL JSONB (binary, indexed)
SELECT data->>'name' FROM users WHERE data @> '{"active": true}';
CREATE INDEX idx_users_data ON users USING GIN (data);
-- MySQL JSON
SELECT JSON_EXTRACT(data, '$.name') FROM users
WHERE JSON_EXTRACT(data, '$.active') = true;
-- 2. Full-Text Search
-- PostgreSQL (built-in tsvector)
SELECT * FROM articles
WHERE to_tsvector('english', content) @@ to_tsquery('postgresql & performance');
-- MySQL FULLTEXT
SELECT * FROM articles
WHERE MATCH(content) AGAINST ('postgresql performance' IN NATURAL LANGUAGE MODE);
-- 3. CTEs (Common Table Expressions)
-- PostgreSQL supports recursive CTEs natively (since 8.4)
WITH RECURSIVE category_tree AS (
SELECT id, name, parent_id, 0 AS level
FROM categories WHERE parent_id IS NULL
UNION ALL
SELECT c.id, c.name, c.parent_id, ct.level + 1
FROM categories c JOIN category_tree ct ON c.parent_id = ct.id
)
SELECT * FROM category_tree ORDER BY level, name;
-- 4. Window Functions (both support, PostgreSQL more complete)
SELECT
employee_id,
salary,
AVG(salary) OVER (PARTITION BY department_id) as dept_avg,
RANK() OVER (PARTITION BY department_id ORDER BY salary DESC) as rank
FROM employees;Performance Comparison
Raw performance depends heavily on workload type. Here is how they compare across common scenarios in 2026.
-- Performance Tuning Examples
-- PostgreSQL: EXPLAIN ANALYZE
EXPLAIN (ANALYZE, BUFFERS, FORMAT JSON)
SELECT u.id, u.name, COUNT(o.id) as order_count
FROM users u
LEFT JOIN orders o ON u.id = o.user_id
WHERE u.created_at > '2025-01-01'
GROUP BY u.id, u.name
ORDER BY order_count DESC
LIMIT 100;
-- PostgreSQL-specific indexes
CREATE INDEX CONCURRENTLY idx_orders_user_status
ON orders (user_id, status)
WHERE status != 'cancelled'; -- Partial index
CREATE INDEX idx_products_attrs ON products USING GIN (attributes); -- JSONB index
-- MySQL: EXPLAIN FORMAT=JSON
EXPLAIN FORMAT=JSON
SELECT u.id, u.name, COUNT(o.id) as order_count
FROM users u
LEFT JOIN orders o ON u.id = o.user_id
WHERE u.created_at > '2025-01-01'
GROUP BY u.id, u.name
ORDER BY order_count DESC
LIMIT 100;
-- Connection pooling configuration
-- PostgreSQL (PgBouncer or pg pool settings)
max_connections = 100 -- in postgresql.conf
-- Use connection pooler for high concurrency
-- PgBouncer pool_mode = transaction (recommended for web apps)
-- MySQL
max_connections = 200 -- in my.cnf
innodb_buffer_pool_size = 4G -- 70-80% of RAM for dedicated MySQL serverWhen to Choose PostgreSQL
PostgreSQL is the right choice when you need advanced SQL features, data integrity guarantees, or complex query capabilities.
- Complex queries — Advanced window functions, CTEs, lateral joins
- JSON/document storage — JSONB with GIN indexes rivals MongoDB
- Geospatial data — PostGIS extension is the gold standard
- Strict data integrity — CHECK constraints, exclusion constraints, custom domains
- High-concurrency writes — MVCC handles concurrent writes better than MySQL
- Full-text search — Built-in, no external service needed
- Analytics/reporting — Better at complex aggregations and window functions
When to Choose MySQL
MySQL remains an excellent choice for many use cases, particularly read-heavy web applications and teams that prioritize simplicity.
- Simple CRUD applications — WordPress, Drupal, and many CMSes default to MySQL
- Read-heavy workloads — InnoDB is highly optimized for read-heavy patterns
- Existing MySQL ecosystem — If your team has deep MySQL expertise
- PlanetScale — MySQL-compatible serverless database with excellent DX
- Replication simplicity — MySQL replication is well-understood and widely deployed
Migrating Between Databases
Migrating from MySQL to PostgreSQL (or vice versa) requires careful planning around SQL dialect differences, data type mapping, and application code changes.
-- MySQL to PostgreSQL Migration: Common Differences
-- 1. AUTO_INCREMENT -> SERIAL/IDENTITY
-- MySQL
CREATE TABLE users (
id INT AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(100)
);
-- PostgreSQL
CREATE TABLE users (
id SERIAL PRIMARY KEY, -- or BIGSERIAL for large tables
name VARCHAR(100)
);
-- Modern PostgreSQL (v10+):
-- id INT GENERATED ALWAYS AS IDENTITY PRIMARY KEY
-- 2. String functions differ
-- MySQL: IFNULL
SELECT IFNULL(phone, 'N/A') FROM users;
-- PostgreSQL: COALESCE (also works in MySQL)
SELECT COALESCE(phone, 'N/A') FROM users;
-- 3. String concatenation
-- MySQL
SELECT CONCAT(first_name, ' ', last_name) FROM users;
-- PostgreSQL
SELECT first_name || ' ' || last_name FROM users;
-- Or use CONCAT (PostgreSQL also supports it)
-- 4. LIMIT/OFFSET syntax (both support the same)
SELECT * FROM users ORDER BY id LIMIT 10 OFFSET 20;
-- 5. Boolean values
-- MySQL: TRUE/FALSE or 1/0
-- PostgreSQL: TRUE/FALSE or 't'/'f' or 'true'/'false'
-- 6. Timestamp with timezone
-- MySQL: DATETIME or TIMESTAMP (local time only)
-- PostgreSQL: TIMESTAMPTZ (timezone-aware, recommended)
ALTER TABLE events
ALTER COLUMN created_at TYPE TIMESTAMPTZ
USING created_at AT TIME ZONE 'UTC';Frequently Asked Questions
Is PostgreSQL faster than MySQL?
It depends on the workload. MySQL is often faster for simple read-heavy queries with proper indexing. PostgreSQL excels at complex analytical queries, writes with many concurrent connections, and workloads requiring advanced features like JSONB or full-text search.
Which database do major cloud providers recommend?
All major cloud providers offer both: AWS Aurora supports both MySQL and PostgreSQL; Google Cloud SQL offers both; Azure Database supports both. Supabase is built on PostgreSQL. PlanetScale is built on MySQL. Both are equally well-supported in the cloud.
Does PostgreSQL support JSON?
Yes, PostgreSQL has exceptional JSON support with the JSONB type, which stores JSON in a binary format with indexing support. It supports querying, indexing, and modifying JSON documents with SQL operators. MySQL also has a JSON type since version 5.7, but PostgreSQL's implementation is generally considered more capable.
Which is better for a new project in 2026?
For most new projects in 2026, PostgreSQL is the recommended default. It has a richer feature set, better standards compliance, and the community momentum is strongly in its favor. MySQL is still the right choice if you are joining an existing MySQL ecosystem or need the specific performance characteristics of MySQL for very high-read workloads.