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5.9 KiB
5.9 KiB
slug |
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/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(UInt8) - Shows whether a setting is obsolete.
Example
The following example shows how to get information about settings which name contains min_i
.
SELECT *
FROM system.settings
WHERE name LIKE '%min_i%'
┌─name───────────────────────────────────────────────_─value─────_─changed─_─description───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────_─min──_─max──_─readonly─_─type─────────_─default───_─alias_for─_─is_obsolete─┐
│ min_insert_block_size_rows │ 1048449 │ 0 │ Squash blocks passed to INSERT query to specified size in rows, if blocks are not big enough. │ ____ │ ____ │ 0 │ UInt64 │ 1048449 │ │ 0 │
│ min_insert_block_size_bytes │ 268402944 │ 0 │ Squash blocks passed to INSERT query to specified size in bytes, if blocks are not big enough. │ ____ │ ____ │ 0 │ UInt64 │ 268402944 │ │ 0 │
│ min_insert_block_size_rows_for_materialized_views │ 0 │ 0 │ Like min_insert_block_size_rows, but applied only during pushing to MATERIALIZED VIEW (default: min_insert_block_size_rows) │ ____ │ ____ │ 0 │ UInt64 │ 0 │ │ 0 │
│ min_insert_block_size_bytes_for_materialized_views │ 0 │ 0 │ Like min_insert_block_size_bytes, but applied only during pushing to MATERIALIZED VIEW (default: min_insert_block_size_bytes) │ ____ │ ____ │ 0 │ UInt64 │ 0 │ │ 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. │ ____ │ ____ │ 0 │ Milliseconds │ 1000 │ │ 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.
SELECT * FROM system.settings WHERE changed AND name='load_balancing'
See also