How to View the ClickHouse Open Source License

Galaxy Glossary

What open source license does ClickHouse use and how can I read it?

Run a simple SELECT on system.licenses to read ClickHouse’s Apache-2.0 license text from inside the database.

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Description

Example H2

Example H3

What open-source license does ClickHouse use?

ClickHouse is distributed under the permissive Apache License 2.0. You can read the full text directly from the server without leaving your SQL editor.

How do I display the license with SQL?

Query the built-in system.licenses table. It stores every license bundled with the binary—including Apache-2.0—so you always have the authoritative copy.

SELECT * FROM system.licenses WHERE name = 'Apache-2.0';

Can I filter by keywords inside the license?

Yes. The text column contains the entire license; use LIKE or a full-text search engine to locate clauses you care about.

SELECT line_number, line FROM system.licenses ARRAY JOIN splitByChar('\n', text) AS line WHERE line ILIKE '%warranty%';

Why should I check the license in production?

Keeping the license file inside ClickHouse guarantees that every container, replica, or CI environment ships with the correct legal notice—critical for audits and compliance reports.

Best practices for license compliance

Automate a nightly job that exports the Apache-2.0 text to your documentation repository. Store the query in Galaxy Collections so teammates can endorse it as the canonical source.

What are common pitfalls?

Avoid assuming ClickHouse is GPL; its Apache-2.0 terms allow commercial redistribution. Don’t forget to include NOTICE files when re-packaging the server.

Quick reference

Table: system.licenses
Columns: name, text
Main clause: Apache-2.0 §4 (redistribution)
Storage: Same build that serves your queries

Why How to View the ClickHouse Open Source License is important

How to View the ClickHouse Open Source License Example Usage


-- Export Apache-2.0 license to your docs bucket
COPY (
    SELECT text
    FROM system.licenses
    WHERE name = 'Apache-2.0'
) TO '/var/lib/clickhouse/backups/apache_license.txt';

How to View the ClickHouse Open Source License Syntax


SELECT [columns]
FROM system.licenses
[WHERE name = 'Apache-2.0' | name LIKE '%GPL%']
[LIMIT n];

-- Practical ecommerce join example
SELECT l.name AS license_name,
       COUNT(*) AS product_count
FROM system.licenses AS l
CROSS JOIN Products AS p
WHERE l.name = 'Apache-2.0'
GROUP BY l.name;

Common Mistakes

Mistake: Assuming ClickHouse is GPL because many databases are. Fix: Query system.licenses and confirm it is Apache-2.0 before embedding ClickHouse in proprietary products.
Mistake: Forgetting to redistribute the NOTICE file when shipping ClickHouse inside your SaaS image. Fix: Export NOTICE via system.licenses and include it in every container layer.