> ## 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_* session settings

> ClickHouse session settings in the join_runtime_* generated group.

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
  }}>Type</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{type}</div>
      <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>Default</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{default_value}</div>
      {changeable_without_restart && <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>
          Changeable without restart
        </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 feature. <u><a href="/docs/docs/beta-and-experimental-features#experimental-features">Learn more.</a></u>
        </div>;
};

These settings are available in [system.settings](/docs/reference/system-tables/settings) and are autogenerated from [source](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp).

<h2 id="join_runtime_bloom_filter_bytes">
  join\_runtime\_bloom\_filter\_bytes
</h2>

<ExperimentalBadge />

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

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

Size in bytes of a bloom filter used as JOIN runtime filter (see enable\_join\_runtime\_filters setting).

<h2 id="join_runtime_bloom_filter_hash_functions">
  join\_runtime\_bloom\_filter\_hash\_functions
</h2>

<ExperimentalBadge />

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

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

Number of hash functions in a bloom filter used as JOIN runtime filter (see enable\_join\_runtime\_filters setting).

<h2 id="join_runtime_bloom_filter_max_ratio_of_set_bits">
  join\_runtime\_bloom\_filter\_max\_ratio\_of\_set\_bits
</h2>

<ExperimentalBadge />

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

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

If the number of set bits in a runtime bloom filter exceeds this ratio the filter is completely disabled to reduce the overhead.

<h2 id="join_runtime_filter_blocks_to_skip_before_reenabling">
  join\_runtime\_filter\_blocks\_to\_skip\_before\_reenabling
</h2>

<ExperimentalBadge />

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

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

Number of blocks that are skipped before trying to dynamically re-enable a runtime filter that previously was disabled due to poor filtering ratio.

<h2 id="join_runtime_filter_exact_values_limit">
  join\_runtime\_filter\_exact\_values\_limit
</h2>

<ExperimentalBadge />

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

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

Maximum number of elements in runtime filter that are stored as is in a set, when this threshold is exceeded it switches to bloom filter.

<h2 id="join_runtime_filter_from_fixed_hash_table">
  join\_runtime\_filter\_from\_fixed\_hash\_table
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.6"},{"label": "1"},{"label": "New setting."}]}]} />

When the hash join build side was converted to a FixedHashMap (see `enable_join_fixed_hash_table_conversion`), use that hash map directly as the runtime filter.

<h2 id="join_runtime_filter_pass_ratio_threshold_for_disabling">
  join\_runtime\_filter\_pass\_ratio\_threshold\_for\_disabling
</h2>

<ExperimentalBadge />

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

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

If ratio of passed rows to checked rows is greater than this threshold the runtime filter is considered as poorly performing and is disabled for the next `join_runtime_filter_blocks_to_skip_before_reenabling` blocks to reduce the overhead.

<h2 id="join_runtime_filter_size_from_hash_table_stats">
  join\_runtime\_filter\_size\_from\_hash\_table\_stats
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.7"},{"label": "1"},{"label": "Use hash table size statistics collected from previous executions to size the JOIN runtime filter. When disabled, fall back to the fixed `join_runtime_bloom_filter_bytes`."}]}]} />

Use hash table size statistics collected from previous executions to size the JOIN runtime filter. When disabled, fall back to the fixed `join_runtime_bloom_filter_bytes`.