Database server

MySQL, MariaDB or Percona Server (Recommended)

MySQL 5.5.3 / MariaDB 5.5.20 / Percona Server 5.5.8 or higher is required with InnoDB as the primary storage engine, and the PDO database extension is required.

Note 1: MySQL 8 is supported only on Drupal 8.6 or later. See this issue.

Note 2: Drupal generally works with the default MySQL configuration. A more complex site may require database configuration changes. You can address these common configuration issues using this documentation.

PostgreSQL

Drupal 8 requires PostgreSQL 9.1.2 or higher (see PostgreSQL support status in Drupal 8).

Drupal 9 requires PostgreSQL 10.0 or higher with the pg_trgm extension (see PostgreSQL support status in Drupal 9).

Note: Some contributed modules are not as abstracted from MySQL-specific code as would be ideal. If you are familiar with PostgreSQL, please file issues with these contributed modules as you encounter them.

SQLite

Supports SQLite 3.6.8 or higher

Note: Some contributed modules are not as abstracted from MySQL-specific code as would be ideal. If you are familiar with SQLite, please report issues with these contributed modules.

Other Database Servers

Microsoft SQL Server and MongoDB are supported via contributed modules.

Please refer to discussions in the Enterprise Group if you are interested in working on database support.