> ## 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_* 会话设置

> ClickHouse 中 allow_statistics_* 自动生成分组里的会话设置。

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
  }}>类型</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{type}</div>
      <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>默认值</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{default_value}</div>
      {changeable_without_restart && <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>
          无需重启即可更改
        </div>}
      {changeable_without_restart && <div style={{
    overflowWrap: "anywhere"
  }}>
          {changeable_without_restart}
        </div>}
    </div>;
};

这些设置可在 [system.settings](/docs/zh/reference/system-tables/settings) 中查看，由 [源代码](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp) 自动生成。

<div id="allow_statistics">
  ## allow\_statistics
</div>

**别名**: `allow_experimental_statistics`

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.3"},{"label": "1"},{"label": "列统计信息现已正式可用"}]}]} />

允许在定义列时使用[统计信息](/docs/zh/reference/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-creating-a-table)，并可[操作统计信息](/docs/zh/reference/engines/table-engines/mergetree-family/mergetree#column-statistics)。

<div id="allow_statistics_optimize">
  ## allow\_statistics\_optimize
</div>

**别名**: `allow_statistic_optimize`

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.12"},{"label": "1"},{"label": "默认启用此优化。"}]}, {"id": "row-2","items": [{"label": "24.6"},{"label": "0"},{"label": "此设置已重命名，之前的名称为 `allow_statistic_optimize`。"}]}]} />

允许使用统计信息来优化查询。