mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-14 03:25:15 +00:00
55 lines
4.6 KiB
Markdown
55 lines
4.6 KiB
Markdown
---
|
||
slug: /en/operations/system-tables/settings
|
||
---
|
||
# settings
|
||
|
||
Contains information about session settings for current user.
|
||
|
||
Columns:
|
||
|
||
- `name` ([String](../../sql-reference/data-types/string.md)) — Setting name.
|
||
- `value` ([String](../../sql-reference/data-types/string.md)) — Setting value.
|
||
- `changed` ([UInt8](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Shows whether a setting is changed from its default value.
|
||
- `description` ([String](../../sql-reference/data-types/string.md)) — Short setting description.
|
||
- `min` ([Nullable](../../sql-reference/data-types/nullable.md)([String](../../sql-reference/data-types/string.md))) — Minimum value of the setting, if any is set via [constraints](../../operations/settings/constraints-on-settings.md#constraints-on-settings). If the setting has no minimum value, contains [NULL](../../sql-reference/syntax.md#null-literal).
|
||
- `max` ([Nullable](../../sql-reference/data-types/nullable.md)([String](../../sql-reference/data-types/string.md))) — Maximum value of the setting, if any is set via [constraints](../../operations/settings/constraints-on-settings.md#constraints-on-settings). If the setting has no maximum value, contains [NULL](../../sql-reference/syntax.md#null-literal).
|
||
- `readonly` ([UInt8](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Shows whether the current user can change the setting:
|
||
- `0` — Current user can change the setting.
|
||
- `1` — Current user can’t change the setting.
|
||
|
||
**Example**
|
||
|
||
The following example shows how to get information about settings which name contains `min_i`.
|
||
|
||
``` sql
|
||
SELECT *
|
||
FROM system.settings
|
||
WHERE name LIKE '%min_i%'
|
||
```
|
||
|
||
``` text
|
||
┌─name────────────────────────────────────────┬─value─────┬─changed─┬─description───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┬─min──┬─max──┬─readonly─┐
|
||
│ min_insert_block_size_rows │ 1048576 │ 0 │ Squash blocks passed to INSERT query to specified size in rows, if blocks are not big enough. │ ᴺᵁᴸᴸ │ ᴺᵁᴸᴸ │ 0 │
|
||
│ min_insert_block_size_bytes │ 268435456 │ 0 │ Squash blocks passed to INSERT query to specified size in bytes, if blocks are not big enough. │ ᴺᵁᴸᴸ │ ᴺᵁᴸᴸ │ 0 │
|
||
│ read_backoff_min_interval_between_events_ms │ 1000 │ 0 │ Settings to reduce the number of threads in case of slow reads. Do not pay attention to the event, if the previous one has passed less than a certain amount of time. │ ᴺᵁᴸᴸ │ ᴺᵁᴸᴸ │ 0 │
|
||
└─────────────────────────────────────────────┴───────────┴─────────┴───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┴──────┴──────┴──────────┘
|
||
```
|
||
|
||
Using of `WHERE changed` can be useful, for example, when you want to check:
|
||
|
||
- Whether settings in configuration files are loaded correctly and are in use.
|
||
- Settings that changed in the current session.
|
||
|
||
<!-- -->
|
||
|
||
``` sql
|
||
SELECT * FROM system.settings WHERE changed AND name='load_balancing'
|
||
```
|
||
|
||
**See also**
|
||
|
||
- [Settings](../../operations/settings/index.md#session-settings-intro)
|
||
- [Permissions for Queries](../../operations/settings/permissions-for-queries.md#settings_readonly)
|
||
- [Constraints on Settings](../../operations/settings/constraints-on-settings.md)
|
||
- [SHOW SETTINGS](../../sql-reference/statements/show.md#show-settings) statement
|