> ## 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.

# max_number_* MergeTree 表设置

> ClickHouse MergeTree 表设置中归入 max_number_* 分组的设置。

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，且是根据 ClickHouse 源代码自动生成的。

<div id="max_number_of_merges_with_ttl_in_pool">
  ## max\_number\_of\_merges\_with\_ttl\_in\_pool
</div>

<SettingsInfoBlock type="UInt64" default_value="2" />

当池中包含生存时间 (TTL) 条目的合并数量
超过指定值时，不再分配
新的包含生存时间 (TTL) 的合并。这样可以为常规合并保留空闲线程，并
避免出现 "parts 过多"

<div id="max_number_of_mutations_for_replica">
  ## max\_number\_of\_mutations\_for\_replica
</div>

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

将每个副本的 part mutations 数量限制为指定值。
零表示每个副本的 mutations 数量不受限制 (执行
仍可能受到其他设置的约束) 。