---
updatedAt: 2026-07-01T12:14:41.000Z
agentTools:
projectIndex: https://docs.validio.io/llms.txt
---
# ClickHouse
Connect Validio to ClickHouse for data quality monitoring.
ClickHouse is an open-source column-oriented database management system that uses SQL queries to generate reports.
This integration supports the following semi-structured datatypes from ClickHouse: Tuple (and named tuples), Nested, and Array. For more information, see Tuple, Nested data structures, and Array in the ClickHouse SQL reference.
# Prerequisites for Integrating with ClickHouse
Any ClickHouse user account with permissions granted to access the relevant databases and tables. For more information about credentials in Validio, see [Credentials](https://docs.validio.io/docs/credentials). For more information about access rights, see ClickHouse documentation.
**Credential Permission Requirements**
Validio Credentials **require** `VIEWER` access rights when connecting to sources to read and access data. Admins must ensure that they do not provide `EDITOR` access rights to their credentials.
You can use the following SQL script to set up a ClickHouse User and Role and grant the necessary permissions for the Source in Validio.
* The user profile has readonly permissions, which means that the user can only execute read queries (such as SELECT).
* The role is also granted remote permissions to fetch the query logs needed to build the lineage relationships.
```sql
CREATE ROLE IF NOT EXISTS validio_role;
CREATE USER IF NOT EXISTS validio_user
IDENTIFIED WITH sha256_password BY '**************'
SETTINGS PROFILE 'readonly'
DEFAULT ROLE validio_role;
GRANT SELECT, SHOW ON mydatabase.* TO validio_role;
GRANT SELECT ON system.query_log TO validio_role;
GRANT SELECT ON system.clusters TO validio_role;
GRANT REMOTE ON *.* to validio_role;
```
For more information about ClickHouse permissions for queries, seeClickHouse documentation.
Relative entropy validators may require more resources to execute on ClickHouse `dev` environments. For example, if you plan to use a relative entropy validator, you might see errors due to limited RAM.
# Add a ClickHouse Credential
To add a credential for ClickHouse,
1. Navigate to **Credentials** and click **+ New credential**.
2. Under **Namespace**, select a namespace where the resources will be created.
3. For **Credential Type**, select **ClickHouse Credential**.
4. Fill in the **Configuration** parameter fields. Refer to the [ClickHouse Credential Parameters](#clickhouse-credential-parameters) table.
5. (Optional) Click **Test credential** to validate that Validio can successfully access the ClickHouse account. If validation fails, check that you provided the correct parameter values.
6. (Optional) Check **Use for catalog and schema checks** to automatically discover assets from this credential and add them to the Catalog page.
7. Click **Create credential**.
Validio will automatically start fetching data and you will be able to view ClickHouse assets and their relationships in the [Catalog](https://docs.validio.io/docs/about-data-catalog) (if selected) and [Lineage](https://docs.validio.io/docs/intro-to-lineage) pages.
Once the credential is created, you can add a [source](https://docs.validio.io/docs/sources) to monitor ClickHouse data.
## ClickHouse Credential Parameters
| Field | Description |
| :--------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Name | The identifier for the credential, which will be used when adding sources. |
| Protocol | Select the ClickHouse client interface: Native (ClickHouse binary), HTTP, or HTTPS. |
| Host | DNS hostname or IP address to the ClickHouse server. |
| Port | Port number of the Clickhouse server. Depending on the protocol, the defaults ports are: 9000 (Native), 8123 (HTTP), 8443 (HTTPS). See the list of default network ports in ClickHouse documentation. |
| Username | Username of the ClickHouse user account with adequate permissions to access the specified database. See creating users and roles in ClickHouse documentation. |
| Password | Password for the ClickHouse user account. |
| Default Database | Name of the default ClickHouse database where the table to read is included. The default database is required for creating the credential, but you can reference another database when creating a ClickHouse source. |
# Add a ClickHouse Source
To add a source for **ClickHouse**,
1. Navigate to **Sources** and click **+ New source**.
2. Under Source type, select **ClickHouse**.
3. Under **Config**,
1. Select the valid **Credential** or create a new credential to authenticate your connection to the data warehouse.
2. You have two options for specifying the dataset and tables to monitor:
1. **Select an existing table** -- Enter the **Database**, **Schema**, and **Table** to specify where the data comes from. Selecting more than one table will create a new source for each table.
2. **Use Custom SQL** -- Write a valid SQL query to specify the tables to monitor.
3. Set the **Polling schedule**, which is how frequently the validators on the source will check for changes.
4. Under **Schema**, click **Continue** to automatically infer the schema fields from the tables you selected. If you select many tables, this operation can take a few minutes to complete.
5. Under **Source details**,
1. Add **Tags** to help group related sources or to use for routing notifications.
2. Add an **Owner** who will be the contact for incident notifications.
3. Assign a **Priority**, which indicates the importance of incidents detected on this source.
6. Click **Continue** to create the source.
Source names are generated automatically and will be displayed when the source creation completes. If there are more than 5 sources, you will see the names for the first five and a count of the remaining sources.