Overview
Both PostgreSQL and MySQL are open-source relational database management systems that have powered web applications for decades. They share SQL as a query language and offer broadly similar capabilities.
PostgreSQL
PostgreSQL, also known as Postgres, is an object-relational database known for its standards compliance, extensibility, and advanced data types. It supports:
- Full SQL standard compliance
- Native JSON and JSONB storage with indexing
- Array data types
- User-defined types and functions
- Advanced indexing (B-tree, Hash, GiST, GIN, BRIN)
- Window functions and CTEs
- Strong ACID compliance
PostgreSQL is the default choice for complex data models, analytical workloads, and applications that require advanced queries.
MySQL
MySQL is the most widely deployed open-source database, particularly associated with the LAMP stack. It supports:
- Good performance for read-heavy workloads
- Simple setup and broad hosting availability
- InnoDB storage engine with ACID compliance
- JSON data type (since version 5.7)
- Replication and clustering
Key Differences
JSON Support
PostgreSQL offers JSONB, a binary JSON type that supports GIN indexing, allowing fast queries on JSON fields.
MySQL has a JSON type but its indexing capabilities are more limited.
Concurrency
PostgreSQL uses Multi-Version Concurrency Control (MVCC) to handle concurrent reads and writes without locking. Readers do not block writers, and writers do not block readers.
Ecosystem
MySQL has broader availability on shared hosting. PostgreSQL is supported by all major cloud providers (Amazon RDS, Google Cloud SQL, Azure, Supabase, Neon). Most modern ORMs including Prisma and Drizzle default to PostgreSQL.
Which to Choose
Choose PostgreSQL when:
- The application requires complex queries, window functions, or CTEs
- JSON and semi-structured data will be stored alongside relational data
- Strong data integrity enforcement is required
- Building with modern tooling (Prisma, Drizzle, Supabase)
Choose MySQL when:
- The project is built on PHP or a platform that has historically used MySQL
- Existing infrastructure is centered on MySQL
- Maximum compatibility with shared hosting is required
For new web application projects built with Node.js on cloud infrastructure, PostgreSQL is the more capable and commonly recommended choice.