Using PostgreSQL with Drupal: Is It a Good Choice in 2025?

Drupal has supported multiple database engines for many years, including both MySQL and PostgreSQL. While MySQL remains the de-facto standard across most Drupal installations, more developers today are exploring PostgreSQL as an alternative — especially those who already rely on it for enterprise applications and microservices.

But is PostgreSQL a practical choice for a real Drupal project in 2025?
This article breaks down everything you need to know.

Why PostgreSQL?

PostgreSQL is an advanced, enterprise-grade, fully ACID-compliant relational database. It offers:

• Strong data integrity

• Better support for complex SQL queries

• Superior JSONB performance

• Rich indexing options

• Extensibility (custom types, operators, functions)

For applications that require strict correctness, complex data modeling, or deep integrations with other systems, PostgreSQL can be a compelling option.

Drupal Core Works Well on PostgreSQL

Drupal core is fully compatible with PostgreSQL.
The database abstraction layer (DBAL) ensures that core queries work transparently across engines.

For simple to moderately complex sites, PostgreSQL performs reliably, stably, and efficiently.

But Here’s the Catch: Contributed Modules

While Drupal core supports PostgreSQL, the ecosystem does not fully follow.

Around 99% of Drupal installations use MySQL or MariaDB, meaning most module maintainers primarily test their code against MySQL. As a result:

• Some modules contain MySQL-specific SQL

• Certain Views integrations generate incompatible PostgreSQL queries

• Custom migrations or install scripts may assume MySQL data types

• Commerce-related modules sometimes rely on MySQL functions

These aren’t constant issues — but they appear often enough to matter.
Most of them are minor "edge cases," yet they can break a site unexpectedly.

Examples of issues seen in real projects:

• Use of GROUP_CONCAT() (MySQL-only) instead of string_agg()

• MySQL-specific functions like IFNULL() instead of COALESCE()

• ORDER BY using mixed data types → PostgreSQL rejects it

• Implicit NULL handling accepted by MySQL but not by PostgreSQL

• ENGINE=InnoDB or UNSIGNED in .install files

These problems are usually fixable with patches — but they require developer time and expertise.

Performance Comparison

When comparing real Drupal workloads, the results are nuanced:

Where MySQL performs better

• High-speed simple reads (typical CMS workloads)

• Large-scale caching layers

• Heavy use of contrib modules optimized for MySQL syntax

Where PostgreSQL shines

• Complex JOIN queries

• Analytics and reporting features

• Large content models with advanced indexing

• Custom modules using JSONB or CTE queries

For most typical Drupal sites, real performance differences are small — compatibility matters much more.

When PostgreSQL Is a Good Fit for Drupal

Use PostgreSQL with Drupal if:

• Your organization already uses PostgreSQL everywhere else

• You maintain strict code quality and can support cross-DB compatibility

• Your module stack is limited and well-tested

• You build data-heavy, custom application logic on top of Drupal

• You want advanced features like JSONB or PostGIS

In these cases, PostgreSQL can be a strong and even superior choice.

When You Should Prefer MySQL/MariaDB

Choose MySQL/MariaDB if:

• You're building an e-commerce website (e.g., Drupal Commerce)

• Your project depends on many contributed modules

• You want maximum ecosystem compatibility

• You prefer a default, well-trodden path with minimal risk

• You don't want to debug SQL differences

In the vast majority of practical Drupal projects, MySQL remains the safest default.

Conclusion

PostgreSQL is a powerful and fully supported option for Drupal — but it is not the default ecosystem choice.
If you are building a project that benefits from PostgreSQL’s advanced capabilities and you have the expertise to handle occasional compatibility issues, Drupal on PostgreSQL can work extremely well.

However, for most standard Drupal websites, especially those relying heavily on contributed modules, MySQL/MariaDB remains the optimal and hassle-free database engine.

If you're deciding between the two, base your choice on your module stack, team experience, and project complexity — not just the theoretical strengths of a database.