Database setup

Configure config/database.yml for MySQL, PostgreSQL, SQLite3, and SQL Server.

Redmine reads database connection settings from config/database.yml. Copy the example file before editing:

cp config/database.yml.example config/database.yml

Use 2-space indentation in this file. Tabs are not valid YAML.

Configuration examples

MySQL

config/database.yml

production:
  adapter: mysql2
  database: redmine
  host: localhost
  username: redmine
  password: "your_password"
  encoding: utf8mb4
  variables:
    transaction_isolation: "READ-COMMITTED"

You can also use the trilogy adapter for MySQL-compatible servers:

config/database.yml

production:
  adapter: trilogy
  database: redmine
  host: localhost
  username: redmine
  password: "your_password"
  encoding: utf8mb4
  variables:
    transaction_isolation: "READ-COMMITTED"

Redmine 5.1.1 and later require transaction_isolation: "READ-COMMITTED" when using MySQL. Without this setting, you may encounter concurrency-related errors. See the MySQL configuration guide for server-level configuration instructions.

PostgreSQL

config/database.yml

production:
  adapter: postgresql
  database: redmine
  host: localhost
  username: postgres
  password: "your_password"

SQLite3

config/database.yml

production:
  adapter: sqlite3
  database: db/redmine.sqlite3

SQLite3 is suitable for development and small single-user deployments. For production use with multiple users, prefer MySQL or PostgreSQL.

SQL Server

config/database.yml

production:
  adapter: sqlserver
  database: redmine
  host: localhost
  username: redmine
  password: "your_password"

Multiple environments

config/database.yml supports separate blocks for production, development, and test environments. Only the production block is used in production deployments:

config/database.yml

production:
  adapter: mysql2
  database: redmine
  host: localhost
  username: redmine
  password: "your_password"
  encoding: utf8mb4
  variables:
    transaction_isolation: "READ-COMMITTED"

development:
  adapter: mysql2
  database: redmine_development
  host: localhost
  username: redmine
  password: "your_password"
  encoding: utf8mb4
  variables:
    transaction_isolation: "READ-COMMITTED"

test:
  adapter: mysql2
  database: redmine_test
  host: localhost
  username: redmine
  password: "your_password"
  encoding: utf8mb4
  variables:
    transaction_isolation: "READ-COMMITTED"

The test database is erased and recreated when running the test suite. Never point it at the same database as development or production.

Connection pooling

Rails manages a connection pool for each environment. You can configure the pool size by adding a pool key:

config/database.yml

production:
  adapter: mysql2
  database: redmine
  host: localhost
  username: redmine
  password: "your_password"
  encoding: utf8mb4
  pool: 10
  variables:
    transaction_isolation: "READ-COMMITTED"

The default pool size is 5. Increase it if you run a multi-threaded application server with many concurrent requests.

Applying the configuration

After editing config/database.yml, run the database migrations to create the schema:

bundle exec rake db:migrate RAILS_ENV="production"

If you change the adapter (e.g. switching from MySQL to PostgreSQL), re-run bundle install so that the correct adapter gem is installed:

bundle install --without development test