> ## Documentation Index
> Fetch the complete documentation index at: https://docs.growthbook.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Setting Up MySQL or MariaDB as a Data Source

> Connect MySQL or MariaDB to GrowthBook with a read-only user, whitelist the Cloud IP if needed, and enter host, port, database, and SSL settings.

GrowthBook runs `SELECT` queries against MySQL or MariaDB to compute experiment results. Create a dedicated read-only user, allow network access from GrowthBook, then add the connection in **Metrics and Data** → **Data Sources**.

## 1. Create a read-only user

Grant `SELECT` only on the database that holds experiment assignment and metric events.

```sql theme={null}
CREATE USER 'growthbook'@'%' IDENTIFIED BY 'use-a-strong-password';
GRANT SELECT ON your_database.* TO 'growthbook'@'%';
FLUSH PRIVILEGES;
```

Tighten the host in `'growthbook'@'%'` if you can restrict the user to the GrowthBook Cloud IP or your self-hosted instance.

## 2. Allow network access

If you use [GrowthBook Cloud](https://app.growthbook.io), whitelist `52.70.79.40` in your MySQL or MariaDB firewall, security group, or cloud allowlist.

Self-hosted GrowthBook runs in Docker. To reach a database on the host machine, use `host.docker.internal` as the host instead of `localhost`.

## 3. Add MySQL or MariaDB in GrowthBook

1. Go to **Metrics and Data** → **Data Sources**.
2. Choose **MySQL / MariaDB** (guided setup if you use a supported event tracker, or manual setup for a custom schema).
3. Enter the connection fields:

| Field           | Notes                                                                                 |
| --------------- | ------------------------------------------------------------------------------------- |
| Host            | Public hostname or IP. Cloud cannot reach `localhost`.                                |
| Port            | Default `3306`.                                                                       |
| Database        | The database GrowthBook should query.                                                 |
| User / Password | The read-only user from step 1.                                                       |
| Require SSL     | Enable if your server requires TLS. You can attach a CA, client cert, and client key. |

4. Save. GrowthBook runs a `SELECT 1` query to confirm the connection.

## 4. Map assignments and metrics

After the connection succeeds, define [experiment assignment queries](/app/datasources#experiment-assignment-queries) and [Fact Tables](/app/metrics). MySQL and MariaDB support the Schema Browser, so you can inspect tables and columns while writing SQL.