MySQL and PostgreSQL are both open-source relational database management systems (RDBMS) that have been in production use for over 25 years, but they differ in design philosophy, feature depth, and community governance. MySQL was acquired by Oracle in 2010 (via the Sun Microsystems acquisition) and focuses on simplicity, read performance, and ease of deployment. PostgreSQL is community-governed under a permissive BSD-like license and emphasizes SQL standards compliance, extensibility, and advanced features.
The most impactful technical difference for modern applications is JSON support. PostgreSQL's JSONB type stores JSON data in a binary format that supports GIN indexing, enabling fast queries on JSON fields without extracting data into relational columns. You can query nested JSON properties, create indexes on JSON paths, and combine relational and document data in a single table. MySQL has a JSON type with basic extraction functions, but it lacks JSONB's indexing capabilities and query operator richness, making it less suitable for semi-structured data workloads.
PostgreSQL's extensibility is another major differentiator. The extension system allows adding new data types, functions, operators, index types, and languages without modifying core code. PostGIS adds geospatial data types and queries. pgvector enables AI/ML vector similarity search. TimescaleDB adds time-series capabilities. pg_trgm provides fuzzy text matching. This extensibility means PostgreSQL can serve as a single database for relational, document, geospatial, time-series, and vector workloads, reducing infrastructure complexity.
MySQL's strengths lie in simplicity and ecosystem. Setting up a MySQL instance requires minimal configuration, and its read performance for simple queries (primary key lookups, single-table scans) is excellent. The WordPress ecosystem, representing over 40% of all websites, runs on MySQL. Drupal, Magento, and many PHP applications were designed for MySQL. This massive install base means abundant hosting options, extensive documentation, and readily available expertise.
| Feature | MySQL | PostgreSQL |
|---|---|---|
| SQL standard compliance | Partial, many MySQL-specific extensions | Most standards-compliant open-source database |
| JSON support | JSON type with basic functions | JSONB with indexing, operators, and full querying |
| Full-text search | Built-in FULLTEXT indexes | Built-in tsvector/tsquery, more powerful |
| Replication | Built-in async and semi-sync replication | Streaming replication, logical replication |
| Read performance (simple queries) | Very fast for simple SELECT queries | Slightly slower for very simple queries |
| Complex query performance | Optimizer handles simple joins well | Advanced query planner for complex queries |
| Extensibility | Limited extension system | Rich extension ecosystem (PostGIS, pgvector, etc.) |
| ACID compliance | InnoDB is ACID compliant | Fully ACID compliant by default |
| Ease of setup | Very easy, minimal configuration needed | Slightly more configuration required |
| Hosting availability | Available on every cloud provider | Available everywhere, growing faster |
| Community and ecosystem | Largest install base, WordPress/Drupal | Fastest-growing, Supabase/Neon/Crunchy |
| Licensing | GPL (Oracle owned), dual-licensed | PostgreSQL License (permissive, BSD-like) |
Use PostgreSQL for applications requiring advanced SQL features, JSONB document storage, geospatial queries (PostGIS), full-text search, or vector similarity search (pgvector). Use MySQL for WordPress sites, simple CRUD applications where ease of setup and simple-query performance are priorities, and legacy systems already built on MySQL. For new projects without specific MySQL requirements, PostgreSQL is the stronger default choice.
Evaluate your data model complexity. If your application stores structured data in normalized tables with straightforward queries (e-commerce product catalogs, user management, content management), both databases work well. If your data model includes semi-structured JSON documents, geospatial coordinates, full-text search, recursive queries (organizational hierarchies, bill of materials), or vector embeddings for AI features, PostgreSQL provides native capabilities that MySQL requires external solutions or workarounds to achieve.
Consider your scaling strategy. For read-heavy workloads, MySQL's built-in replication and compatibility with ProxySQL make horizontal read scaling straightforward. PostgreSQL's streaming replication and logical replication support similar patterns. For write-heavy workloads, both databases support partitioning, but PostgreSQL's declarative partitioning and parallel query execution handle complex analytical queries better. Cloud-native PostgreSQL services like Neon (serverless branching), Supabase (instant APIs), and Crunchy Data offer modern scaling features.
Think about licensing and governance. MySQL is dual-licensed under GPL and a commercial license controlled by Oracle. While the open-source version is freely available, Oracle's control has concerned the community, leading to forks like MariaDB. PostgreSQL uses a permissive BSD-like license with no corporate owner, governed by a global community of contributors. This governance model provides more predictability for long-term projects.
For either database, use PinusX's SQL Formatter to format and beautify your queries with 100% client-side processing. SQL queries often contain table structures, column names, and query patterns that reveal your application architecture. PinusX ensures this information stays in your browser without being transmitted to any server.
It depends on the workload. MySQL is slightly faster for very simple queries (primary key lookups, single-table scans) due to its simpler query optimizer. PostgreSQL outperforms MySQL on complex queries involving multiple joins, subqueries, window functions, and aggregations because of its more sophisticated query planner. For most real-world applications, the performance difference is negligible compared to query optimization and indexing choices.
Not directly. WordPress core requires MySQL or MariaDB and does not support PostgreSQL. Some plugins and forks have attempted PostgreSQL compatibility, but they are not production-ready and break many WordPress plugins that use MySQL-specific SQL syntax. If you want PostgreSQL, consider a different CMS or build a custom application.
PostgreSQL is significantly better for JSON workloads. Its JSONB type stores JSON in an optimized binary format with GIN index support, enabling fast queries on any JSON path without extracting data into relational columns. MySQL's JSON type supports basic extraction functions but lacks comparable indexing and query operator support. If your application stores semi-structured data, PostgreSQL's JSONB is a major advantage.
PostgreSQL is the fastest-growing database and has been DB-Engines Database of the Year multiple times. New projects increasingly default to PostgreSQL, especially in the startup and cloud-native ecosystem. However, MySQL's massive install base (WordPress alone powers 40% of websites) ensures it will remain widely used for many years. Both databases continue to be actively developed.
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