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145 lines
6.0 KiB
Markdown
145 lines
6.0 KiB
Markdown
---
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slug: /en/operations/system-tables/settings
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---
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# settings
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Contains information about session settings for current user.
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Columns:
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- `name` ([String](../../sql-reference/data-types/string.md)) — Setting name.
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- `value` ([String](../../sql-reference/data-types/string.md)) — Setting value.
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- `changed` ([UInt8](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Shows whether a setting is changed from its default value.
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- `description` ([String](../../sql-reference/data-types/string.md)) — Short setting description.
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- `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).
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- `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).
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- `readonly` ([UInt8](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Shows whether the current user can change the setting:
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- `0` — Current user can change the setting.
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- `1` — Current user can’t change the setting.
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- `default` ([String](../../sql-reference/data-types/string.md)) — Setting default value.
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- `is_obsolete` ([UInt8](../../sql-reference/data-types/int-uint.md#uint-ranges)) - Shows whether a setting is obsolete.
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- `tier` ([Enum8](../../sql-reference/data-types/enum.md)) — Support level for this feature. ClickHouse features are organized in tiers, varying depending on the current status of their development and the expectations one might have when using them. Values:
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- `'Production'` — The feature is stable, safe to use and does not have issues interacting with other **production** features. .
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- `'Beta'` — The feature is stable and safe. The outcome of using it together with other features is unknown and correctness is not guaranteed. Testing and reports are welcome.
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- `'Experimental'` — The feature is under development. Only intended for developers and ClickHouse enthusiasts. The feature might or might not work and could be removed at any time.
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- `'Obsolete'` — No longer supported. Either it is already removed or it will be removed in future releases.
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**Example**
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The following example shows how to get information about settings which name contains `min_i`.
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``` sql
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SELECT *
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FROM system.settings
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WHERE name LIKE '%min_insert_block_size_%'
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FORMAT Vertical
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```
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``` text
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Row 1:
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──────
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name: min_insert_block_size_rows
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value: 1048449
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changed: 0
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description: Sets the minimum number of rows in the block that can be inserted into a table by an `INSERT` query. Smaller-sized blocks are squashed into bigger ones.
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Possible values:
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- Positive integer.
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- 0 — Squashing disabled.
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min: ᴺᵁᴸᴸ
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max: ᴺᵁᴸᴸ
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readonly: 0
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type: UInt64
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default: 1048449
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alias_for:
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is_obsolete: 0
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tier: Production
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Row 2:
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──────
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name: min_insert_block_size_bytes
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value: 268402944
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changed: 0
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description: Sets the minimum number of bytes in the block which can be inserted into a table by an `INSERT` query. Smaller-sized blocks are squashed into bigger ones.
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Possible values:
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- Positive integer.
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- 0 — Squashing disabled.
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min: ᴺᵁᴸᴸ
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max: ᴺᵁᴸᴸ
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readonly: 0
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type: UInt64
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default: 268402944
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alias_for:
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is_obsolete: 0
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tier: Production
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Row 3:
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──────
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name: min_insert_block_size_rows_for_materialized_views
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value: 0
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changed: 0
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description: Sets the minimum number of rows in the block which can be inserted into a table by an `INSERT` query. Smaller-sized blocks are squashed into bigger ones. This setting is applied only for blocks inserted into [materialized view](../../sql-reference/statements/create/view.md). By adjusting this setting, you control blocks squashing while pushing to materialized view and avoid excessive memory usage.
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Possible values:
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- Any positive integer.
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- 0 — Squashing disabled.
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**See Also**
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- [min_insert_block_size_rows](#min-insert-block-size-rows)
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min: ᴺᵁᴸᴸ
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max: ᴺᵁᴸᴸ
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readonly: 0
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type: UInt64
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default: 0
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alias_for:
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is_obsolete: 0
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tier: Production
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Row 4:
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──────
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name: min_insert_block_size_bytes_for_materialized_views
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value: 0
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changed: 0
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description: Sets the minimum number of bytes in the block which can be inserted into a table by an `INSERT` query. Smaller-sized blocks are squashed into bigger ones. This setting is applied only for blocks inserted into [materialized view](../../sql-reference/statements/create/view.md). By adjusting this setting, you control blocks squashing while pushing to materialized view and avoid excessive memory usage.
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Possible values:
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- Any positive integer.
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- 0 — Squashing disabled.
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**See also**
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- [min_insert_block_size_bytes](#min-insert-block-size-bytes)
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min: ᴺᵁᴸᴸ
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max: ᴺᵁᴸᴸ
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readonly: 0
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type: UInt64
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default: 0
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alias_for:
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is_obsolete: 0
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tier: Production
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```
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Using of `WHERE changed` can be useful, for example, when you want to check:
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- Whether settings in configuration files are loaded correctly and are in use.
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- Settings that changed in the current session.
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<!-- -->
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``` sql
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SELECT * FROM system.settings WHERE changed AND name='load_balancing'
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```
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**See also**
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- [Settings](../../operations/settings/index.md#session-settings-intro)
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- [Permissions for Queries](../../operations/settings/permissions-for-queries.md#settings_readonly)
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- [Constraints on Settings](../../operations/settings/constraints-on-settings.md)
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- [SHOW SETTINGS](../../sql-reference/statements/show.md#show-settings) statement
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