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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  • is_obsolete (UInt8) - Shows whether a setting is obsolete.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