> ## 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.

# min_free_* 会话设置

> ClickHouse 中 min_free_* 自动生成分组下的会话设置。

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，并由 [源代码](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp) 自动生成。

<div id="min_free_disk_bytes_to_perform_insert">
  ## min\_free\_disk\_bytes\_to\_perform\_insert
</div>

<SettingsInfoBlock type="UInt64" default_value="0" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "24.9"},{"label": "0"},{"label": "在仍允许临时写入的情况下，为 插入 预留一定的空闲磁盘空间（字节）。"}]}, {"id": "row-2","items": [{"label": "24.10"},{"label": "0"},{"label": "新设置。"}]}]} />

执行 插入 所需的最小空闲磁盘空间 (字节) 。

<div id="min_free_disk_ratio_to_perform_insert">
  ## min\_free\_disk\_ratio\_to\_perform\_insert
</div>

<SettingsInfoBlock type="Float" default_value="0" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "24.9"},{"label": "0"},{"label": "在仍允许临时写入的情况下，按总磁盘空间的占比为插入操作保留一部分空闲磁盘空间。"}]}, {"id": "row-2","items": [{"label": "24.10"},{"label": "0"},{"label": "新设置。"}]}]} />

执行插入所需的最小空闲磁盘空间占比。

<div id="min_free_disk_space_for_temporary_data">
  ## min\_free\_disk\_space\_for\_temporary\_data
</div>

<SettingsInfoBlock type="UInt64" default_value="0" />

写入用于外部排序和聚合的临时数据时，需保留的最小磁盘空间。