> ## Documentation Index
> Fetch the complete documentation index at: https://clickhouse.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# allow_statistics_* session settings

> ClickHouse session settings in the allow_statistics_* generated group.

export const SettingsInfoBlock = ({type, default_value, changeable_without_restart}) => {
  return <div className="not-prose" style={{
    display: "flex",
    flexWrap: "wrap",
    alignItems: "baseline",
    columnGap: "0.5rem",
    rowGap: "0.125rem",
    margin: "0.375rem 0",
    fontSize: "0.8125rem",
    lineHeight: "1.125rem"
  }}>
      <div style={{
    fontWeight: 600,
    opacity: 0.72
  }}>Type</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{type}</div>
      <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>Default</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{default_value}</div>
      {changeable_without_restart && <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>
          Changeable without restart
        </div>}
      {changeable_without_restart && <div style={{
    overflowWrap: "anywhere"
  }}>
          {changeable_without_restart}
        </div>}
    </div>;
};

These settings are available in [system.settings](/docs/reference/system-tables/settings) and are autogenerated from [source](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp).

<h2 id="allow_statistics">
  allow\_statistics
</h2>

**Aliases**: `allow_experimental_statistics`

<SettingsInfoBlock type="Bool" default_value="1" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.3"},{"label": "1"},{"label": "Column statistics are now GA"}]}]} />

Allows defining columns with [statistics](/docs/reference/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-creating-a-table) and [manipulate statistics](/docs/reference/engines/table-engines/mergetree-family/mergetree#column-statistics).

<h2 id="allow_statistics_optimize">
  allow\_statistics\_optimize
</h2>

**Aliases**: `allow_statistic_optimize`

<SettingsInfoBlock type="Bool" default_value="1" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.12"},{"label": "1"},{"label": "Enable this optimization by default."}]}, {"id": "row-2","items": [{"label": "24.6"},{"label": "0"},{"label": "The setting was renamed. The previous name is `allow_statistic_optimize`."}]}]} />

Allows using statistics to optimize queries