ClickHouse
Prerequisites
- The hostname for the ClickHouse (opens in a new tab) database server
- The username/password (opens in a new tab) for the ClickHouse (opens in a new tab) database server
Setup
Manual
Add the following to a .env file in your Cube project:
CUBEJS_DB_TYPE=clickhouse
CUBEJS_DB_HOST=my.clickhouse.host
CUBEJS_DB_NAME=my_clickhouse_database
CUBEJS_DB_USER=clickhouse_user
CUBEJS_DB_PASS=**********Environment Variables
| Environment Variable | Description | Possible Values | Required | Supports multiple data sources? |
|---|---|---|---|---|
CUBEJS_DB_HOST | The host URL for a database | A valid database host URL | ✅ | ✅ |
CUBEJS_DB_PORT | The port for the database connection | A valid port number | ❌ | ✅ |
CUBEJS_DB_NAME | The name of the database to connect to | A valid database name | ✅ | ✅ |
CUBEJS_DB_USER | The username used to connect to the database | A valid database username | ✅ | ✅ |
CUBEJS_DB_PASS | The password used to connect to the database | A valid database password | ✅ | ✅ |
CUBEJS_DB_CLICKHOUSE_READONLY | Whether the ClickHouse user has read-only access or not | true, false | ❌ | ✅ |
CUBEJS_CONCURRENCY | The number of concurrent connections each queue has to the database. Default is 5 | A valid number | ❌ | ❌ |
CUBEJS_DB_MAX_POOL | The maximum number of concurrent database connections to pool. Default is 20 | A valid number | ❌ | ✅ |
Pre-Aggregation Feature Support
count_distinct_approx
Measures of type
count_distinct_approx can
not be used in pre-aggregations when using ClickHouse as a source database.
Pre-Aggregation Build Strategies
To learn more about pre-aggregation build strategies, head here.
| Feature | Works with read-only mode? | Is default? |
|---|---|---|
| Batching | ✅ | ✅ |
| Export Bucket | - | - |
By default, ClickHouse uses batching to build pre-aggregations.
Batching
No extra configuration is required to configure batching for ClickHouse.
Export Bucket
ClickHouse does not support export buckets.
SSL
To enable SSL-encrypted connections between Cube and ClickHouse, set the
CUBEJS_DB_SSL environment variable to true. For more information on how to
configure custom certificates, please check out Enable SSL Connections to the
Database.
Additional Configuration
You can connect to a ClickHouse database when your user's permissions are
restricted (opens in a new tab) to read-only, by setting
CUBEJS_DB_CLICKHOUSE_READONLY to true.