> ## 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.

# distributed_index_analysis_* 会话设置

> 属于自动生成的 distributed_index_analysis_* 组的 ClickHouse 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>;
};

export const ExperimentalBadge = () => {
  return <div className="experimentalBadge">
            <div className="experimentalIcon">
            <svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
                <path strokeWidth="1.25" d="M5.5 2H10.5" stroke="currentColor" strokeLinecap="round" strokeLinejoin="round" />
                <path strokeWidth="1.25" d="M9.50015 2V6.19625L13.4283 12.7425C13.4738 12.8183 13.4985 12.9049 13.4996 12.9934C13.5008 13.0818 13.4785 13.169 13.435 13.246C13.3914 13.323 13.3283 13.3871 13.2519 13.4317C13.1755 13.4764 13.0886 13.4999 13.0002 13.5H3.00015C2.91164 13.5 2.8247 13.4766 2.74822 13.432C2.67174 13.3874 2.60847 13.3233 2.56487 13.2463C2.52126 13.1693 2.49889 13.082 2.50004 12.9935C2.50119 12.905 2.52582 12.8184 2.5714 12.7425L6.50015 6.19625V2" stroke="currentColor" strokeLinecap="round" strokeLinejoin="round" />
                <path strokeWidth="1.25" d="M4.47656 9.56754C5.30344 9.41254 6.47656 9.47942 7.99969 10.25C10.0153 11.2707 11.4216 11.0569 12.2184 10.7282" stroke="currentColor" strokeLinecap="round" strokeLinejoin="round" />
            </svg>
        </div>
            Experimental 功能。 <u><a href="/docs/docs/beta-and-experimental-features#experimental-features">了解详情。</a></u>
        </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="distributed_index_analysis">
  ## distributed\_index\_analysis
</div>

<ExperimentalBadge />

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.1"},{"label": "0"},{"label": "新的实验性设置"}]}]} />

分布式索引分析将在各副本之间分布式执行。
这对共享存储以及 cluster 中海量数据的场景尤为有利。
使用来自 cluster\_for\_parallel\_replicas 的副本。

**另请参见**

* [distributed\_index\_analysis\_for\_non\_shared\_merge\_tree](/docs/zh/reference/settings/session-settings/distributed-index-analysis#distributed_index_analysis_for_non_shared_merge_tree)
* [distributed\_index\_analysis\_min\_parts\_to\_activate](/docs/zh/reference/settings/merge-tree-settings#distributed_index_analysis_min_parts_to_activate)
* [distributed\_index\_analysis\_min\_indexes\_bytes\_to\_activate](/docs/zh/reference/settings/merge-tree-settings#distributed_index_analysis_min_indexes_bytes_to_activate)

<div id="distributed_index_analysis_for_non_shared_merge_tree">
  ## distributed\_index\_analysis\_for\_non\_shared\_merge\_tree
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.1"},{"label": "0"},{"label": "新增设置"}]}]} />

即使是非 SharedMergeTree (仅 Cloud 提供的引擎) ，也启用分布式索引分析。

<div id="distributed_index_analysis_only_on_coordinator">
  ## distributed\_index\_analysis\_only\_on\_coordinator
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.4"},{"label": "0"},{"label": "新设置。"}]}]} />

如果启用，分布式索引分析将仅在协调器上执行。
这样可以避免在谓词包含子查询时 (例如 `IN (SELECT ...)`) 生成 O(N^2) 个查询，
因为否则每个 follower 副本都会各自独立触发自己的分布式索引分析；
但如果子查询中使用了大型表，则会降低分布式索引分析的效率。