> ## 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.

# refresh_* MergeTree table settings

> ClickHouse MergeTree table settings in the refresh_* 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.merge\_tree\_settings](/docs/reference/system-tables/merge_tree_settings) and are autogenerated from ClickHouse source.

<h2 id="refresh_parts_interval">
  refresh\_parts\_interval
</h2>

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

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

If it is greater than zero - refresh the list of data parts from the underlying filesystem to check if the data was updated under the hood.
It can be set only if the table is located on readonly disks (which means that this is a readonly replica, while data is being written by another replica).

<h2 id="refresh_statistics_interval">
  refresh\_statistics\_interval
</h2>

<SettingsInfoBlock type="Seconds" default_value="300" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.2"},{"label": "300"},{"label": "Enable statistics cache"}]}, {"id": "row-2","items": [{"label": "25.11"},{"label": "0"},{"label": "New setting"}]}]} />

The interval of refreshing statistics cache in seconds. If it is set to zero, the refreshing will be disabled.