OpenMetadata/openmetadata-docs/content/v1.7.x-SNAPSHOT/connectors/database/clickhouse/index.md

title	slug
Clickhouse	/connectors/database/clickhouse

{% connectorDetailsHeader name="Clickhouse" stage="PROD" platform="OpenMetadata" availableFeatures=["Metadata", "Query Usage", "Lineage", "Column-level Lineage", "Data Profiler", "Data Quality", "dbt", "Sample Data", "Reverse Metadata Ingestion"] unavailableFeatures=["Owners", "Tags", "Stored Procedures"] / %}

In this section, we provide guides and references to use the Clickhouse connector.

Configure and schedule Clickhouse metadata and profiler workflows from the OpenMetadata UI:

• Requirements
  • Profiler & Data Quality
  • Usage & Lineage
• Metadata Ingestion
  • Service Name
  • Connection Options
  • Metadata Ingestion Options
• Troubleshooting
  • Workflow Deployment Error
• Related
• Reverse Metadata

{% partial file="/v1.7/connectors/ingestion-modes-tiles.md" variables={yamlPath: "/connectors/database/clickhouse/yaml"} /%}

Requirements

Clickhouse user must grant SELECT privilege on system.* and schema/tables to fetch the metadata of tables and views.

• Create a new user
• More details https://clickhouse.com/docs/en/sql-reference/statements/create/user

CREATE USER <username> IDENTIFIED WITH sha256_password BY <password>

• Grant Permissions
• More details on permissions can be found here at https://clickhouse.com/docs/en/sql-reference/statements/grant

-- Grant SELECT and SHOW to that user
-- More details on permissions can be found here at https://clickhouse.com/docs/en/sql-reference/statements/grant
GRANT SELECT, SHOW ON system.* to <username>;
GRANT SELECT ON <schema_name>.* to <username>;

Profiler & Data Quality

Executing the profiler workflow or data quality tests, will require the user to have SELECT permission on the tables/schemas where the profiler/tests will be executed. More information on the profiler workflow setup can be found here and data quality tests here.

Usage & Lineage

For the usage and lineage workflow, the user will need SELECT privilege. You can find more information on the usage workflow here and the lineage workflow here.

Metadata Ingestion

{% partial file="/v1.7/connectors/metadata-ingestion-ui.md" variables={ connector: "Clickhouse", selectServicePath: "/images/v1.7/connectors/clickhouse/select-service.png", addNewServicePath: "/images/v1.7/connectors/clickhouse/add-new-service.png", serviceConnectionPath: "/images/v1.7/connectors/clickhouse/service-connection.png", } /%}

{% stepsContainer %} {% extraContent parentTagName="stepsContainer" %}

Connection Options

• Username: Specify the User to connect to Clickhouse. It should have enough privileges to read all the metadata.
• Password: Password to connect to Clickhouse.
• Host and Port: Enter the fully qualified hostname and port number for your Clickhouse deployment in the Host and Port field.
• Use HTTPS Protocol: Enable this flag when the when the Clickhouse instance is hosted via HTTPS protocol. This flag is useful when you are using clickhouse+http connection scheme.
• Secure Connection: Establish secure connection with ClickHouse. ClickHouse supports secure communication over SSL/TLS to protect data in transit, by checking this option, it establishes secure connection with ClickHouse. This flag is useful when you are using clickhouse+native connection scheme.
• Key File: The key file path is the location when ClickHouse looks for a file containing the private key needed for secure communication over SSL/TLS. By default, ClickHouse will look for the key file in the /etc/clickhouse-server directory, with the file name server.key. However, this can be customized in the ClickHouse configuration file (config.xml). This flag is useful when you are using clickhouse+native connection scheme and the secure connection flag is enabled.

{% partial file="/v1.7/connectors/database/advanced-configuration.md" /%}

{% /extraContent %}

{% partial file="/v1.7/connectors/test-connection.md" /%}

{% partial file="/v1.7/connectors/database/configure-ingestion.md" /%}

{% partial file="/v1.7/connectors/ingestion-schedule-and-deploy.md" /%}

{% /stepsContainer %}

{% partial file="/v1.7/connectors/database/related.md" /%}

Reverse Metadata

{% note %} This feature is specific to Collate and requires the Collate Enterprise License. {% /note %}

Description Management

Clickhouse supports description updates at the following levels:

• Table level
• Column level

Owner Management

❌ Owner management is not supported for Clickhouse.

Tag Management

❌ Tag management is not supported for Clickhouse.

Custom SQL Template

Clickhouse supports custom SQL templates for metadata changes. The template is interpreted using python f-strings.

Here are examples of custom SQL queries for metadata changes:

-- Update column description
ALTER TABLE `{schema}`.{table} MODIFY COLUMN {column} COMMENT {description};

The list of variables for custom SQL can be found here.

For more details about reverse metadata ingestion, visit our Reverse Metadata Documentation.