Settings

This page describes the RawTree engine binary used to generate this reference. It does not define Query API support. Descriptions retain upstream ClickHouse terminology. See SQL interface scope.

Session settings control one query or a role's defaults. MergeTree settings control table storage and data parts. Server settings control database server behavior.

Set a session setting in a query with the SETTINGS clause.

SELECT 1 SETTINGS max_threads = 1

Use a settings profile to assign supported defaults to database roles. See settings profile statements and the settings profile guide.

The SQL engine sets table-scoped settings in CREATE TABLE ... SETTINGS.

The Query API accepts CREATE TABLE ... SETTINGS, except on databases with custom S3 storage. See the CREATE TABLE reference.

• Session settings
• MergeTree settings
• Server settings
• CREATE TABLE
• SELECT statements