> ## 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.

# zero_copy_* MergeTree table settings

> ClickHouse MergeTree table settings in the zero_copy_* 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="zero_copy_concurrent_part_removal_max_postpone_ratio">
  zero\_copy\_concurrent\_part\_removal\_max\_postpone\_ratio
</h2>

<SettingsInfoBlock type="Float" default_value="0.05" />

Max percentage of top level parts to postpone removal in order to get
smaller independent ranges. Recommended not to change.

<h2 id="zero_copy_concurrent_part_removal_max_split_times">
  zero\_copy\_concurrent\_part\_removal\_max\_split\_times
</h2>

<SettingsInfoBlock type="UInt64" default_value="5" />

Max recursion depth for splitting independent Outdated parts ranges into
smaller subranges. Recommended not to change.

<h2 id="zero_copy_merge_mutation_min_parts_size_sleep_before_lock">
  zero\_copy\_merge\_mutation\_min\_parts\_size\_sleep\_before\_lock
</h2>

<SettingsInfoBlock type="UInt64" default_value="1073741824" />

If zero copy replication is enabled sleep random amount of time before trying
to lock depending on parts size for merge or mutation

<h2 id="zero_copy_merge_mutation_min_parts_size_sleep_no_scale_before_lock">
  zero\_copy\_merge\_mutation\_min\_parts\_size\_sleep\_no\_scale\_before\_lock
</h2>

<SettingsInfoBlock type="UInt64" default_value="0" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.3"},{"label": "0"},{"label": "New setting"}]}]} />

If zero copy replication is enabled sleep random amount of time up to 500ms
before trying to lock for merge or mutation.