> ## 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.

# use_skip_indexes_* session settings

> ClickHouse session settings in the use_skip_indexes_* 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="use_skip_indexes">
  use\_skip\_indexes
</h2>

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

Use data skipping indexes during query execution.

Possible values:

* 0 — Disabled.
* 1 — Enabled.

<h2 id="use_skip_indexes_for_disjunctions">
  use\_skip\_indexes\_for\_disjunctions
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.12"},{"label": "1"},{"label": "New setting"}]}]} />

Evaluate WHERE filters with mixed AND and OR conditions using skip indexes. Example: WHERE A = 5 AND (B = 5 OR C = 5).
If disabled, skip indexes are still used to evaluate WHERE conditions but they must only contain AND-ed clauses.

Possible values:

* 0 — Disabled.
* 1 — Enabled.

<h2 id="use_skip_indexes_for_top_k">
  use\_skip\_indexes\_for\_top\_k
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.5"},{"label": "1"},{"label": "Enable using data skipping indexes for TopK filtering by default"}]}, {"id": "row-2","items": [{"label": "25.12"},{"label": "0"},{"label": "New setting."}]}]} />

Enable using data skipping indexes for TopK filtering.

When enabled, if a minmax skip index exists on the column in `ORDER BY <column> LIMIT n` query, optimizer will attempt to use the minmax index to skip granules that are not relevant for the final result . This can reduce query latency.

Possible values:

* 0 — Disabled.
* 1 — Enabled.

<h2 id="use_skip_indexes_if_final">
  use\_skip\_indexes\_if\_final
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.6"},{"label": "1"},{"label": "Change in default value of setting"}]}]} />

Controls whether skipping indexes are used when executing a query with the FINAL modifier.

Skip indexes may exclude rows (granules) containing the latest data, which could lead to incorrect results from a query with the FINAL modifier. When this setting is enabled, skipping indexes are applied even with the FINAL modifier, potentially improving performance but with the risk of missing recent updates. This setting should be enabled in sync with the setting use\_skip\_indexes\_if\_final\_exact\_mode (default is enabled).

Possible values:

* 0 — Disabled.
* 1 — Enabled.

<h2 id="use_skip_indexes_if_final_exact_mode">
  use\_skip\_indexes\_if\_final\_exact\_mode
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.6"},{"label": "1"},{"label": "Change in default value of setting"}]}, {"id": "row-2","items": [{"label": "25.5"},{"label": "0"},{"label": "This setting was introduced to help FINAL query return correct results with skip indexes"}]}]} />

Controls whether granules returned by a skipping index are expanded in newer parts to return correct results when executing a query with the FINAL modifier.

Using skip indexes may exclude rows (granules) containing the latest data which could lead to incorrect results. This setting can ensure that correct results are returned by scanning newer parts that have overlap with the ranges returned by the skip index. This setting should be disabled only if approximate results based on looking up the skip index are okay for an application.

Possible values:

* 0 — Disabled.
* 1 — Enabled.

<h2 id="use_skip_indexes_on_data_read">
  use\_skip\_indexes\_on\_data\_read
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.2"},{"label": "1"},{"label": "The text index is now GA"}]}, {"id": "row-2","items": [{"label": "26.1"},{"label": "0"},{"label": "Default enable"}]}, {"id": "row-3","items": [{"label": "25.9"},{"label": "0"},{"label": "New setting"}]}]} />

Enable using data skipping indexes during data reading.

When enabled, skip indexes are evaluated dynamically at the time each data granule is being read, rather than being analyzed in advance before query execution begins. This can reduce query startup latency.

Possible values:

* 0 — Disabled.
* 1 — Enabled.