ClickHouse

ClickHouse is an open-source column-oriented database management system that allows generating analytical data reports in real-time. The ClickHouse integration in Secoda allows you to connect your ClickHouse instance to catalog and document your data.

Getting Started with ClickHouse

Create a user with the following permissions

• SELECT access on system tables (system.tables, system.columns)

• SELECT access on the databases and tables you want to catalog

• Access to query history information

• If using metadata push capabilities, the user needs ALTER permissions on tables

Gather the additional information:

• Host name of your ClickHouse instance, e.g., wo3evzjkve.us-east-1.aws.clickhouse.cloud

• Port number, e.g., 8443

• Username with access to ClickHouse

• Password for authentication

Setup

1. In Secoda, navigate to the Integrations page

2. Click "Add Integration"

3. Select "ClickHouse" from the list of available integrations

4. Fill in the following credentials:

Host: your-clickhouse-host
Port: 8443
User: your-username
Password: your-password

1. Click "Test Connection"

2. Select databases and schemas

3. Click "Continue" to trigger the initial sync

See ClickHouse Metadata Extractedfor the full list of information sycned from ClickHouse.

Monitoring Capabilities

The ClickHouse integration supports various monitoring features:

• Table row counts

• Table freshness

• Column-level statistics, e.g., null % and unique %.

Troubleshooting

Common issues and solutions:

1. Connection Failed

   • Verify the host and port are correct

   • Ensure the user has proper permissions

   • Check if the ClickHouse server is accessible from your network

2. Missing Tables

   • Verify the user has SELECT permissions on the schemas

   • Check if tables are in system or information_schema databases (these are excluded)

3. Query History Not Showing

   • Ensure the user has access to system tables

   • Verify query history retention settings in ClickHouse

Limitations

• External tables may have limited metadata support

• Some system tables are excluded from extraction

• Query history retention depends on ClickHouse settings

• Metadata push is not supported for external tables

FAQ

Q: Can I connect to multiple ClickHouse instances? A: Yes, you can create multiple ClickHouse integrations in Secoda, each pointing to a different instance.

Q: Does the integration support SSL connections? A: Yes, ClickHouse connections are secured using standard SSL/TLS protocols.

Q: How often does the integration sync? A: By default, the integration syncs once per week, but this can be configured in the integration settings.

Q: Can I preview data in Secoda? A: Yes, the integration supports data preview capabilities for tables and query results.