MySQL vs PostgreSQL in 2026: Which Database Should You Choose?

Choosing between MySQL and PostgreSQL is one of the most common decisions database administrators and developers face. Both are mature, open-source relational database management systems with decades of development behind them, but they serve different use cases and have distinct strengths.

In this comprehensive comparison, we examine MySQL and PostgreSQL across the dimensions that matter most in 2026: performance, features, data integrity, scalability, ecosystem, and real-world use cases.

Quick Overview

MySQL (now at version 9.x) is owned by Oracle and remains the most widely deployed open-source database in the world. It powers a significant portion of the web, including WordPress, Drupal, and countless web applications. MySQL prioritizes speed and simplicity for read-heavy workloads.

PostgreSQL (now at version 17.x) is a community-driven project known for its standards compliance, extensibility, and advanced features. It is increasingly the database of choice for applications requiring complex queries, data integrity, and advanced data types.

Performance Comparison

Read Performance

MySQL has traditionally excelled at simple read operations, particularly when using the InnoDB storage engine with properly configured buffer pools. For straightforward SELECT queries on well-indexed tables, MySQL often edges out PostgreSQL by 5-15% in throughput.

However, PostgreSQL has closed this gap significantly with recent versions. PostgreSQL 17 includes improved query planning, parallel query execution, and better index-only scans that bring its read performance very close to MySQL for most workloads.

Write Performance

PostgreSQL generally handles concurrent write operations more efficiently, thanks to its Multi-Version Concurrency Control (MVCC) implementation. PostgreSQL creates new versions of rows rather than locking them, allowing readers and writers to operate without blocking each other.

MySQL's InnoDB also uses MVCC, but its implementation can lead to more lock contention under heavy concurrent write workloads, particularly with complex transactions.

Complex Queries

PostgreSQL is the clear winner for complex analytical queries. Its query planner is more sophisticated, supporting advanced join strategies, partial indexes, Common Table Expressions (CTEs) with optimization, and better handling of subqueries.

-- PostgreSQL: Window functions with complex partitioning
SELECT
    department,
    employee_name,
    salary,
    AVG(salary) OVER (PARTITION BY department) as dept_avg,
    salary - AVG(salary) OVER (PARTITION BY department) as diff_from_avg,
    PERCENT_RANK() OVER (PARTITION BY department ORDER BY salary) as percentile
FROM employees
ORDER BY department, salary DESC;

Feature Comparison

Data Types

PostgreSQL offers a significantly richer set of data types:

JSON/JSONB — PostgreSQL's JSONB type is indexable and supports efficient querying. MySQL has JSON support but with fewer operators and no binary storage optimization.
Arrays — PostgreSQL supports native array columns. MySQL does not have native array support.
Range types — Date ranges, numeric ranges, and custom ranges. Unique to PostgreSQL.
Network types — INET, CIDR, and MACADDR types with built-in validation and operators.
UUID — Native UUID type with generation functions. MySQL stores UUIDs as CHAR(36) or BINARY(16).
Full-text search — Both support full-text search, but PostgreSQL's implementation is more flexible with custom dictionaries and ranking functions.

Indexing

PostgreSQL supports more index types than MySQL:

B-tree — Both databases (default for both)
Hash — Both databases
GiST — PostgreSQL only (generalized search tree for geometric and full-text data)
GIN — PostgreSQL only (generalized inverted index, excellent for JSONB and arrays)
BRIN — PostgreSQL only (block range index, efficient for large sequential datasets)
Partial indexes — PostgreSQL only (index only rows matching a condition)
Expression indexes — PostgreSQL only (index on computed expressions)

-- PostgreSQL: Partial index (only index active users)
CREATE INDEX idx_active_users ON users (email) WHERE active = true;

-- PostgreSQL: Expression index (case-insensitive search)
CREATE INDEX idx_lower_email ON users (LOWER(email));

-- PostgreSQL: GIN index on JSONB column
CREATE INDEX idx_metadata ON products USING GIN (metadata);

SQL Standards Compliance

PostgreSQL is more SQL-standards compliant than MySQL. This matters for portability and for writing correct, predictable queries. Key differences include:

PostgreSQL enforces GROUP BY requirements strictly; MySQL's ONLY_FULL_GROUP_BY mode is off by default in older versions
PostgreSQL's NULL handling is more standards-compliant
PostgreSQL supports CHECK constraints fully; MySQL historically ignored them (fixed in 8.0.16+)

Scalability and Replication

Replication

Both databases support replication, but with different approaches:

MySQL offers native Group Replication, InnoDB Cluster, and traditional master-replica replication. MySQL's replication ecosystem is mature and well-documented, with tools like ProxySQL for connection routing.

PostgreSQL provides streaming replication, logical replication (for selective table replication), and can use extensions like Patroni and Citus for high availability and horizontal scaling.

Connection Handling

MySQL uses a thread-per-connection model that handles moderate concurrent connections efficiently. PostgreSQL uses a process-per-connection model that can become resource-heavy at very high connection counts. Most PostgreSQL deployments use PgBouncer as a connection pooler to address this.

When to Choose MySQL

WordPress and PHP applications — MySQL is the default and most tested database for the PHP ecosystem
Simple read-heavy workloads — Content management systems, blogs, and catalog-style applications
Hosted/managed environments — MySQL is available on virtually every hosting provider
Existing MySQL expertise — If your team already knows MySQL well, switching has a cost
Maximum compatibility — More applications and frameworks have been tested with MySQL

When to Choose PostgreSQL

Complex data models — Applications with sophisticated relationships, constraints, and data types
Analytics and reporting — Complex queries, window functions, and data aggregation
GIS/Geospatial — PostGIS extension makes PostgreSQL the leading open-source spatial database
Data integrity is paramount — Financial applications, healthcare, and regulatory-compliant systems
JSON-heavy workloads — Applications that need to query and index semi-structured data efficiently
Modern application stacks — Django, Rails, Node.js applications increasingly default to PostgreSQL

The Verdict

There is no universally "better" database. MySQL remains excellent for web applications, content management, and read-heavy workloads where simplicity and compatibility are priorities. PostgreSQL is the stronger choice for applications requiring advanced features, complex queries, strict data integrity, and extensibility.

In 2026, the trend is clearly moving toward PostgreSQL for new projects, particularly in cloud-native environments. But MySQL's massive ecosystem, hosting availability, and simplicity ensure it will remain relevant for years to come.

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MySQL vs PostgreSQL in 2026: Which Database Should You Choose?

Quick Overview