Connect to ClickHouse (Beta)

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This documentation describes one or more private beta features that are in development. Beta features are subject to quick, iterative changes; therefore the current user experience in the Sigma service can differ from the information provided in this page.
This page should not be considered official published documentation until Sigma removes this notice and the beta flag on the corresponding feature(s) in the Sigma service. For the full beta feature disclaimer, see Beta features.
If you are interested in joining a limited test group and enabling this feature in your Sigma organization, contact Support or reach out to your Account Executive.

Sigma supports secure connections to ClickHouse. This document explains how to connect your Sigma organization to your ClickHouse server, and describes relevant feature limitations.

User requirements

You must be assigned the Admin account type.
Your ClickHouse version should be actively supported by ClickHouse (stable or lts versions). See the ClickHouse documentation on ClickHouse releases. Your ClickHouse version must be v24.2 or above.
Your ClickHouse server must be accessible over the public internet using basic authentication (username and password).

Create a ClickHouse connection

Click the user icon at the top right of your screen. The user icon is usually composed of your initials.
In the drop-down menu, select Add connection. The Add new connection page appears.
In the Connection Details section, specify the following:


Name	Enter a Name for the new connection. Sigma displays this name in the connection list.
Type	Select ClickHouse.

In the Connection credentials section, specify the following:


Host	The address of your ClickHouse server as an IP address or URL.
Port	The port through which Sigma should connect to your ClickHouse server. The default is `8443`. Connections are only supported for ports `8443` (if you want to use HTTPS with TLS enabled), or `8123` (if you want to use HTTP with TLS disabled).
User	The username for connecting to your ClickHouse server.
Password	The password for connecting to your ClickHouse server.
Enable TLS	Turn the toggle on or off to enable or disable TLS (transport layer security) encryption for your ClickHouse connection. TLS is recommended for all connections. You cannot disable TLS if you are using port `8443`, or the connection will be unsuccessful.

In the Connection features section, specify the following:


Connection timeout	The time before timeout (or cancellation), in seconds, that Sigma waits for the query to return results. The default is 120, or 2 minutes. The maximum is 600, or 10 minutes.
Connection queue size	The number of interactive queries Sigma can run on this connection concurrently. The default is 8.
Use friendly names	Turn the toggle on or off. Friendly names make column names from the data source more readable. For example, a database column ORDER_NUMBER or OrderNumber appears as Order Number.

Select Create.
Once your connection has been created, select Browse Connection. You can then select Add permission to grant data access for users in your organization. See Data access overview.

Limitations

Currently, ClickHouse connections don’t support the following features:

OAuth and SAML authentication
Private link connections
OAuth connections
Secure Shell (SSH) protocol connections
Input table and write back functionality, including: CSV uploads, use of input tables, running Python code
Stored procedures
Dataset warehouse views
Export to cloud storage
Sigma result IDs cache
User attributes for role and warehouse switching
Sample connections
The following functions:
- All Geography functions
- All Array functions
- The following Date functions: DateParse and ConvertTimezone. Date functions may not work as expected for timestamps before 1970.

Updated 1 day ago