Settings

Settings are configured in layers, so each subsequent layer redefines the previous settings.

Ways to configure settings, in order of priority:

• Settings in the server configuration file.

• Query settings.

  • When starting the ClickHouse console client in non-interactive mode, set the startup parameter .
  • Make settings in the SETTINGS clause of the SELECT query. The setting value is applied only to that query and is reset to default or previous value after the query is executed.

In addition to the common , users can define custom settings.

A custom setting name must begin with one of predefined prefixes. The list of these prefixes must be declared in the custom_settings_prefixes parameter in the server configuration file.

To define a custom setting use command:

See Also