mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-14 03:25:15 +00:00
62 lines
1.4 KiB
Markdown
62 lines
1.4 KiB
Markdown
---
|
|
slug: /en/sql-reference/statements/alter/setting
|
|
sidebar_position: 38
|
|
sidebar_label: SETTING
|
|
---
|
|
|
|
# Table Settings Manipulations
|
|
|
|
There is a set of queries to change table settings. You can modify settings or reset them to default values. A single query can change several settings at once.
|
|
If a setting with the specified name does not exist, then the query raises an exception.
|
|
|
|
**Syntax**
|
|
|
|
``` sql
|
|
ALTER TABLE [db].name [ON CLUSTER cluster] MODIFY|RESET SETTING ...
|
|
```
|
|
|
|
:::note
|
|
These queries can be applied to [MergeTree](../../../engines/table-engines/mergetree-family/mergetree.md) tables only.
|
|
:::
|
|
|
|
## MODIFY SETTING
|
|
|
|
Changes table settings.
|
|
|
|
**Syntax**
|
|
|
|
```sql
|
|
MODIFY SETTING setting_name=value [, ...]
|
|
```
|
|
|
|
**Example**
|
|
|
|
```sql
|
|
CREATE TABLE example_table (id UInt32, data String) ENGINE=MergeTree() ORDER BY id;
|
|
|
|
ALTER TABLE example_table MODIFY SETTING max_part_loading_threads=8, max_parts_in_total=50000;
|
|
```
|
|
|
|
## RESET SETTING
|
|
|
|
Resets table settings to their default values. If a setting is in a default state, then no action is taken.
|
|
|
|
**Syntax**
|
|
|
|
```sql
|
|
RESET SETTING setting_name [, ...]
|
|
```
|
|
|
|
**Example**
|
|
|
|
```sql
|
|
CREATE TABLE example_table (id UInt32, data String) ENGINE=MergeTree() ORDER BY id
|
|
SETTINGS max_part_loading_threads=8;
|
|
|
|
ALTER TABLE example_table RESET SETTING max_part_loading_threads;
|
|
```
|
|
|
|
**See Also**
|
|
|
|
- [MergeTree settings](../../../operations/settings/merge-tree-settings.md)
|