> ## 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.

# join_runtime_* 会话设置

> ClickHouse 的 join_runtime_* 组会话设置。

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

<div id="join_runtime_bloom_filter_bytes">
  ## join\_runtime\_bloom\_filter\_bytes
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="UInt64" default_value="524288" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.10"},{"label": "524288"},{"label": "新增设置"}]}]} />

用作 JOIN 运行时过滤器的布隆过滤器大小 (以字节为单位)  (参见 enable\_join\_runtime\_filters 设置) 。

<div id="join_runtime_bloom_filter_hash_functions">
  ## join\_runtime\_bloom\_filter\_hash\_functions
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="UInt64" default_value="3" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.10"},{"label": "3"},{"label": "新设置"}]}]} />

用作 JOIN 运行时过滤器的布隆过滤器中的哈希函数数量 (参见 enable\_join\_runtime\_filters 设置) 。

<div id="join_runtime_bloom_filter_max_ratio_of_set_bits">
  ## join\_runtime\_bloom\_filter\_max\_ratio\_of\_set\_bits
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Double" default_value="0.7" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.1"},{"label": "0.7"},{"label": "新增设置"}]}]} />

如果运行时布隆过滤器中的置位比例超过该比率，则会完全禁用该过滤器，以降低开销。

<div id="join_runtime_filter_blocks_to_skip_before_reenabling">
  ## join\_runtime\_filter\_blocks\_to\_skip\_before\_reenabling
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="UInt64" default_value="30" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.1"},{"label": "30"},{"label": "新设置"}]}]} />

在尝试动态重新启用先前因过滤比率不佳而被禁用的运行时过滤器之前，需要跳过的块数。

<div id="join_runtime_filter_exact_values_limit">
  ## join\_runtime\_filter\_exact\_values\_limit
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="UInt64" default_value="10000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.10"},{"label": "10000"},{"label": "新设置"}]}]} />

运行时过滤器中以原样形式存储在集合中的元素最大数量；超过此阈值时，将切换为布隆过滤器。

<div id="join_runtime_filter_from_fixed_hash_table">
  ## join\_runtime\_filter\_from\_fixed\_hash\_table
</div>

<SettingsInfoBlock type="Bool" default_value="1" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.6"},{"label": "1"},{"label": "新设置。"}]}]} />

当 hash join 的构建侧被转换为 FixedHashMap (参见 `enable_join_fixed_hash_table_conversion`) 时，直接将该哈希表用作运行时过滤器。

<div id="join_runtime_filter_pass_ratio_threshold_for_disabling">
  ## join\_runtime\_filter\_pass\_ratio\_threshold\_for\_disabling
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Double" default_value="0.7" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.1"},{"label": "0.7"},{"label": "新设置"}]}]} />

如果通过的行数与已检查行数的比率高于此阈值，则会认为运行时过滤器效果不佳，并在接下来的 `join_runtime_filter_blocks_to_skip_before_reenabling` 个块内将其禁用，以减少开销。

<div id="join_runtime_filter_size_from_hash_table_stats">
  ## join\_runtime\_filter\_size\_from\_hash\_table\_stats
</div>

<SettingsInfoBlock type="Bool" default_value="1" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.7"},{"label": "1"},{"label": "使用从之前执行中收集的哈希表大小统计信息来确定 JOIN 运行时过滤器的大小。禁用后，将回退到固定的 `join_runtime_bloom_filter_bytes`。"}]}]} />

使用从之前执行中收集的哈希表大小统计信息来确定 JOIN 运行时过滤器的大小。禁用后，将回退到固定的 `join_runtime_bloom_filter_bytes`。