> ## 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.

# joined_* session settings

> ClickHouse session settings in the joined_* 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>;
};

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="joined_block_split_single_row">
  joined\_block\_split\_single\_row
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.10"},{"label": "0"},{"label": "New setting"}]}]} />

Allow to chunk hash join result by rows corresponding to single row from left table.
This may reduce memory usage in case of row with many matches in right table, but may increase CPU usage.
Note that `max_joined_block_size_rows != 0` is mandatory for this setting to have effect.
The `max_joined_block_size_bytes` combined with this setting is helpful to avoid excessive memory usage in case of skewed data with some large rows having many matches in right table.

<h2 id="joined_subquery_requires_alias">
  joined\_subquery\_requires\_alias
</h2>

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

Force joined subqueries and table functions to have aliases for correct name qualification.