How to Connect ClickHouse to Looker

Galaxy Glossary

How do I connect ClickHouse to Looker?

Configure Looker to query ClickHouse through a JDBC connection string, set up SSL, and verify schema access.

Sign up for the latest in SQL knowledge from the Galaxy Team!
Welcome to the Galaxy, Guardian!
You'll be receiving a confirmation email

Follow us on twitter :)
Oops! Something went wrong while submitting the form.

Description

Table of Contents

What connection settings does Looker require for ClickHouse?

Provide Host, Port (default 8123 for HTTP or 9000 for native), Database, Username, Password, and JDBC Parameters. Set Dialect to clickhouse in Looker’s Admin → Connections panel.

How do I write the JDBC URL?

Use jdbc:clickhouse://HOST:PORT/DATABASE?user=USER&password=PWD&ssl=true&sslmode=none. Replace placeholders with actual values. ssl=true avoids plain-text credentials.

Should I use HTTP or Native port?

Pick 8123 (HTTP) for ease or 9440 for HTTPS. Use 9000 only if Looker’s dialect supports native port in your version.Always match protocol and port.

How do I test the connection?

Click “Test” in Looker. A green check means Looker can authenticate, open the schema, and run SELECT 1 on ClickHouse.

How do I model ClickHouse tables in LookML?

Create a view for each fact or dimension. Reference ClickHouse tables directly, e.g., sql_table_name: Orders ;;. Use LookML derived tables for aggregates.

What performance tweaks help?

Set connect_timeout and socket_timeout JDBC parameters to 30 000 ms. Enable max_execution_time for runaway queries.Use materialized views in ClickHouse for Looker Explores.

.

Why How to Connect ClickHouse to Looker is important

How to Connect ClickHouse to Looker Example Usage


SELECT customer_id,
       sum(total_amount)        AS lifetime_value,
       count()                  AS order_count
FROM Orders
GROUP BY customer_id
ORDER BY lifetime_value DESC
LIMIT 10;

How to Connect ClickHouse to Looker Syntax


jdbc:clickhouse://<HOST>:<PORT>/<DATABASE>?user=<USERNAME>&password=<PASSWORD>[&ssl=<true|false>][&sslmode=<mode>]

-- Example
jdbc:clickhouse://analytics.myshop.com:9440/production?user=looker&password=s3cret&ssl=true&sslmode=none

Common Mistakes

Frequently Asked Questions (FAQs)

Does Looker support ClickHouse array and nested types?

Looker can read them as strings. Use arrayJoin or JSONExtract in derived tables for analysis.

Can I use SSL certificates instead of passwords?

Yes. Point JDBC parameters to sslkey, sslcert, and sslrootcert files on the Looker host.

How do I limit Looker’s query time?

Add max_execution_time=30 (seconds) in the JDBC string or set it globally in ClickHouse.

Want to learn about other SQL terms?

Trusted by top engineers on high-velocity teams
Aryeo Logo
Assort Health
Curri
Rubie Logo
Bauhealth Logo
Truvideo Logo
Welcome to the Galaxy, Guardian!
You'll be receiving a confirmation email

Follow us on twitter :)
Oops! Something went wrong while submitting the form.