> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-vortex-format.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# use_query_* session settings

> ClickHouse session settings in the use_query_* generated group.

export const VersionHistory = ({rows = []}) => {
  if (rows.length === 0) {
    return null;
  }
  const headers = ["Version", "Default value", "Comment"];
  const border = "1px solid rgba(128, 128, 128, 0.3)";
  const cell = {
    border,
    padding: "0.25rem 0.5rem",
    textAlign: "start",
    verticalAlign: "top"
  };
  return <details className="not-prose" style={{
    border,
    borderRadius: "0.5rem",
    margin: "0.5rem 0",
    padding: "0.5rem 0.75rem",
    fontSize: "0.8125rem",
    lineHeight: "1.125rem"
  }}>
      <summary style={{
    cursor: "pointer",
    fontWeight: 600,
    opacity: 0.72
  }}>
        Version history
      </summary>
      <table style={{
    borderCollapse: "collapse",
    width: "100%",
    margin: "0.5rem 0 0"
  }}>
        <thead>
          <tr>
            {headers.map(header => <th key={header} style={{
    ...cell,
    fontWeight: 600,
    opacity: 0.72
  }}>
                {header}
              </th>)}
          </tr>
        </thead>
        <tbody>
          {rows.map((row, row_index) => <tr key={row.id ?? row_index}>
              {(row.items ?? []).map((item, item_index) => <td key={item_index} style={{
    ...cell,
    overflowWrap: "anywhere"
  }}>
                  {item?.label}
                </td>)}
            </tr>)}
        </tbody>
      </table>
    </details>;
};

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

<h2 id="use_query_cache">
  use\_query\_cache
</h2>

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

If turned on, `SELECT` queries may utilize the [query cache](/concepts/features/performance/caches/query-cache). Parameters [enable\_reads\_from\_query\_cache](/reference/settings/session-settings/enable#enable_reads_from_query_cache)
and [enable\_writes\_to\_query\_cache](/reference/settings/session-settings/enable#enable_writes_to_query_cache) control in more detail how the cache is used.

Possible values:

* 0 - Disabled
* 1 - Enabled

<h2 id="use_query_condition_cache">
  use\_query\_condition\_cache
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.4"},{"label": "1"},{"label": "A new optimization"}]}, {"id": "row-2","items": [{"label": "25.3"},{"label": "0"},{"label": "New setting."}]}]} />

Enable the [query condition cache](/concepts/features/performance/caches/query-condition-cache). The cache stores ranges of granules in data parts which do not satisfy the condition in the `WHERE` clause,
and reuse this information as an ephemeral index for subsequent queries.

Possible values:

* 0 - Disabled
* 1 - Enabled

<h2 id="use_query_condition_cache_for_top_k">
  use\_query\_condition\_cache\_for\_top\_k
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.8"},{"label": "0"},{"label": "New setting to gate the query condition cache for `ORDER BY ... LIMIT n` (TopK) reads; disabled by default."}]}]} />

Enable the [query condition cache](/concepts/features/performance/caches/query-condition-cache) for queries that use the `ORDER BY <column> LIMIT n` (TopK) optimization (dynamic filtering or skip-index based). When disabled, such reads neither consult nor populate the cache.

Such queries can drop granules during execution depending on the running threshold, so their cache entries are partitioned by the TopK plan parameters and by the set of parts read. This setting is disabled by default while the soundness of these cache entries is being established; it has no effect unless `use_query_condition_cache` is also enabled.

Possible values:

* 0 - Disabled
* 1 - Enabled