> ## 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.

# zero_copy_* MergeTree 表设置

> 自动生成的 zero_copy_* 组中的 ClickHouse MergeTree 表设置。

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.merge\_tree\_settings](/docs/zh/reference/system-tables/merge_tree_settings) 中查看，且由 ClickHouse 源代码自动生成。

<div id="zero_copy_concurrent_part_removal_max_postpone_ratio">
  ## zero\_copy\_concurrent\_part\_removal\_max\_postpone\_ratio
</div>

<SettingsInfoBlock type="Float" default_value="0.05" />

为获得更小的独立范围，可延后删除的顶层 parts 的最大百分比。
建议不要修改。

<div id="zero_copy_concurrent_part_removal_max_split_times">
  ## zero\_copy\_concurrent\_part\_removal\_max\_split\_times
</div>

<SettingsInfoBlock type="UInt64" default_value="5" />

将独立的过期分区片段范围拆分为
更小子范围时的最大递归深度。建议不要修改。

<div id="zero_copy_merge_mutation_min_parts_size_sleep_before_lock">
  ## zero\_copy\_merge\_mutation\_min\_parts\_size\_sleep\_before\_lock
</div>

<SettingsInfoBlock type="UInt64" default_value="1073741824" />

如果启用了零拷贝复制，则会在尝试加锁前，根据用于合并或变更的 parts 大小随机等待一段时间

<div id="zero_copy_merge_mutation_min_parts_size_sleep_no_scale_before_lock">
  ## zero\_copy\_merge\_mutation\_min\_parts\_size\_sleep\_no\_scale\_before\_lock
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.3"},{"label": "0"},{"label": "新增设置"}]}]} />

如果启用了零拷贝复制，则在尝试为合并或变更加锁之前，会先随机休眠一段最长 500ms 的时间。