mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-11 17:02:25 +00:00
32 lines
1.5 KiB
Markdown
32 lines
1.5 KiB
Markdown
---
|
|
slug: /en/sql-reference/statements/truncate
|
|
sidebar_position: 52
|
|
sidebar_label: TRUNCATE
|
|
---
|
|
|
|
# TRUNCATE Statements
|
|
|
|
## TRUNCATE TABLE
|
|
``` sql
|
|
TRUNCATE TABLE [IF EXISTS] [db.]name [ON CLUSTER cluster]
|
|
```
|
|
|
|
Removes all data from a table. When the clause `IF EXISTS` is omitted, the query returns an error if the table does not exist.
|
|
|
|
The `TRUNCATE` query is not supported for [View](../../engines/table-engines/special/view.md), [File](../../engines/table-engines/special/file.md), [URL](../../engines/table-engines/special/url.md), [Buffer](../../engines/table-engines/special/buffer.md) and [Null](../../engines/table-engines/special/null.md) table engines.
|
|
|
|
You can use the [alter_sync](../../operations/settings/settings.md#alter-sync) setting to set up waiting for actions to be executed on replicas.
|
|
|
|
You can specify how long (in seconds) to wait for inactive replicas to execute `TRUNCATE` queries with the [replication_wait_for_inactive_replica_timeout](../../operations/settings/settings.md#replication-wait-for-inactive-replica-timeout) setting.
|
|
|
|
:::note
|
|
If the `alter_sync` is set to `2` and some replicas are not active for more than the time, specified by the `replication_wait_for_inactive_replica_timeout` setting, then an exception `UNFINISHED` is thrown.
|
|
:::
|
|
|
|
## TRUNCATE DATABASE
|
|
``` sql
|
|
TRUNCATE DATABASE [IF EXISTS] [db.]name [ON CLUSTER cluster]
|
|
```
|
|
|
|
Removes all tables from a database but keeps the database itself. When the clause `IF EXISTS` is omitted, the query returns an error if the database does not exist.
|