mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-11 08:52:06 +00:00
6.0 KiB
6.0 KiB
slug |
---|
/en/operations/system-tables/settings |
settings
Contains information about session settings for current user.
Columns:
name
(String) — Setting name.value
(String) — Setting value.changed
(UInt8) — Shows whether a setting is changed from its default value.description
(String) — Short setting description.min
(Nullable(String)) — Minimum value of the setting, if any is set via constraints. If the setting has no minimum value, contains NULL.max
(Nullable(String)) — Maximum value of the setting, if any is set via constraints. If the setting has no maximum value, contains NULL.readonly
(UInt8) — Shows whether the current user can change the setting:0
— Current user can change the setting.1
— Current user can’t change the setting.
default
(String) — Setting default value.is_obsolete
(UInt8) - Shows whether a setting is obsolete.tier
(Enum8) — 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:'Production'
— The feature is stable, safe to use and does not have issues interacting with other production features. .'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.'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.'Obsolete'
— No longer supported. Either it is already removed or it will be removed in future releases.
Example
The following example shows how to get information about settings which name contains min_i
.
SELECT *
FROM system.settings
WHERE name LIKE '%min_insert_block_size_%'
FORMAT Vertical
Row 1:
──────
name: min_insert_block_size_rows
value: 1048449
changed: 0
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.
Possible values:
- Positive integer.
- 0 — Squashing disabled.
min: ᴺᵁᴸᴸ
max: ᴺᵁᴸᴸ
readonly: 0
type: UInt64
default: 1048449
alias_for:
is_obsolete: 0
tier: Production
Row 2:
──────
name: min_insert_block_size_bytes
value: 268402944
changed: 0
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.
Possible values:
- Positive integer.
- 0 — Squashing disabled.
min: ᴺᵁᴸᴸ
max: ᴺᵁᴸᴸ
readonly: 0
type: UInt64
default: 268402944
alias_for:
is_obsolete: 0
tier: Production
Row 3:
──────
name: min_insert_block_size_rows_for_materialized_views
value: 0
changed: 0
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.
Possible values:
- Any positive integer.
- 0 — Squashing disabled.
**See Also**
- [min_insert_block_size_rows](#min-insert-block-size-rows)
min: ᴺᵁᴸᴸ
max: ᴺᵁᴸᴸ
readonly: 0
type: UInt64
default: 0
alias_for:
is_obsolete: 0
tier: Production
Row 4:
──────
name: min_insert_block_size_bytes_for_materialized_views
value: 0
changed: 0
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.
Possible values:
- Any positive integer.
- 0 — Squashing disabled.
**See also**
- [min_insert_block_size_bytes](#min-insert-block-size-bytes)
min: ᴺᵁᴸᴸ
max: ᴺᵁᴸᴸ
readonly: 0
type: UInt64
default: 0
alias_for:
is_obsolete: 0
tier: Production
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.
SELECT * FROM system.settings WHERE changed AND name='load_balancing'
See also