> ## 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.

# parts_to_* MergeTree table settings

> ClickHouse MergeTree table settings in the parts_to_* 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="parts_to_delay_insert">
  parts\_to\_delay\_insert
</h2>

<SettingsInfoBlock type="UInt64" default_value="1000" />

If the number of active parts in a single partition exceeds the
`parts_to_delay_insert` value, an `INSERT` is artificially slowed down.

Possible values:

* Any positive integer.

ClickHouse artificially executes `INSERT` longer (adds 'sleep') so that the
background merge process can merge parts faster than they are added.

<h2 id="parts_to_throw_insert">
  parts\_to\_throw\_insert
</h2>

<SettingsInfoBlock type="UInt64" default_value="3000" />

If the number of active parts in a single partition exceeds the
`parts_to_throw_insert` value, `INSERT` is interrupted with the `Too many
parts (N). Merges are processing significantly slower than inserts`
exception.

Possible values:

* Any positive integer.

To achieve maximum performance of `SELECT` queries, it is necessary to
minimize the number of parts processed, see [Merge Tree](/docs/resources/develop-contribute/introduction/architecture#merge-tree).

Prior to version 23.6 this setting was set to 300. You can set a higher
different value, it will reduce the probability of the `Too many parts`
error, but at the same time `SELECT` performance might degrade. Also in case
of a merge issue (for example, due to insufficient disk space) you will
notice it later than you would with the original 300.