# Settings (/docs/reference/sql/settings)



Settings [#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](/docs/reference/clickhouse-compatibility#service-interfaces).

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.

```sql test
SELECT 1 SETTINGS max_threads = 1
```

Use a settings profile to assign supported defaults to database roles.
See [settings profile statements](/docs/reference/sql/statements/settings-profile) and the [settings profile guide](/docs/guides/operate/settings-profiles).

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](/docs/reference/sql/statements/create-table).

* [Session settings](/docs/reference/sql/settings)
* [MergeTree settings](/docs/reference/sql/settings)
* [Server settings](/docs/reference/sql/settings)
* [CREATE TABLE](/docs/reference/sql/statements/create-table)
* [SELECT statements](/docs/reference/sql/statements/select)