> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-postgresql-tls-support.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# replicated_fetches_* MergeTree 表设置

> 归入 replicated_fetches_* 自动生成分组的 ClickHouse MergeTree 表设置。

export const VersionHistory = ({rows = []}) => {
  if (rows.length === 0) {
    return null;
  }
  const headers = ["版本", "默认值", "注释"];
  const border = "1px solid rgba(128, 128, 128, 0.3)";
  const cell = {
    border,
    padding: "0.25rem 0.5rem",
    textAlign: "start",
    verticalAlign: "top"
  };
  return <details className="not-prose" style={{
    border,
    borderRadius: "0.5rem",
    margin: "0.5rem 0",
    padding: "0.5rem 0.75rem",
    fontSize: "0.8125rem",
    lineHeight: "1.125rem"
  }}>
      <summary style={{
    cursor: "pointer",
    fontWeight: 600,
    opacity: 0.72
  }}>
        版本历史
      </summary>
      <table style={{
    borderCollapse: "collapse",
    width: "100%",
    margin: "0.5rem 0 0"
  }}>
        <thead>
          <tr>
            {headers.map(header => <th key={header} style={{
    ...cell,
    fontWeight: 600,
    opacity: 0.72
  }}>
                {header}
              </th>)}
          </tr>
        </thead>
        <tbody>
          {rows.map((row, row_index) => <tr key={row.id ?? row_index}>
              {(row.items ?? []).map((item, item_index) => <td key={item_index} style={{
    ...cell,
    overflowWrap: "anywhere"
  }}>
                  {item?.label}
                </td>)}
            </tr>)}
        </tbody>
      </table>
    </details>;
};

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](/zh/reference/system-tables/merge_tree_settings) 中查看，由 ClickHouse 源代码自动生成。

<div id="replicated_fetches_http_connection_timeout">
  ## replicated\_fetches\_http\_connection\_timeout
</div>

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

已废弃，不起任何作用。

<div id="replicated_fetches_http_receive_timeout">
  ## replicated\_fetches\_http\_receive\_timeout
</div>

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

已废弃，不起任何作用。

<div id="replicated_fetches_http_send_timeout">
  ## replicated\_fetches\_http\_send\_timeout
</div>

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

已废弃，无任何作用。

<div id="replicated_fetches_min_part_level">
  ## replicated\_fetches\_min\_part\_level
</div>

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

从其他副本拉取的最小 分片 级别。低于此阈值的 分片s 会被延后处理
(即保留在复制队列中，并在每个调度周期重新评估，而不是被永久跳过) 。
将其设为 1 可延后拉取 level-0 (未合并) 的 分片s，从而在高强度摄取期间降低复制开销。
默认值：0 (无论级别如何都会拉取所有 分片s) 。

<div id="replicated_fetches_min_part_level_timeout_seconds">
  ## replicated\_fetches\_min\_part\_level\_timeout\_seconds
</div>

<SettingsInfoBlock type="UInt64" default_value="300" />

超过该超时时间 (秒) 后，即使低于 replicated\_fetches\_min\_part\_level 的 分片s，也仍会被拉取。
使用 0 可禁用此超时 (低于最小级别的 分片s 将被无限期推迟，直到合并) 。
默认值：300 (5 分钟后强制拉取) 。