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

# delta_lake_* session settings

> ClickHouse session settings in the delta_lake_* 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="delta_lake_enable_engine_predicate">
  delta\_lake\_enable\_engine\_predicate
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.8"},{"label": "1"},{"label": "New setting"}]}]} />

Enables delta-kernel internal data pruning.

<h2 id="delta_lake_enable_expression_visitor_logging">
  delta\_lake\_enable\_expression\_visitor\_logging
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.8"},{"label": "0"},{"label": "New setting"}]}]} />

Enables Test level logs of DeltaLake expression visitor. These logs can be too verbose even for test logging.

<h2 id="delta_lake_insert_max_bytes_in_data_file">
  delta\_lake\_insert\_max\_bytes\_in\_data\_file
</h2>

<SettingsInfoBlock type="NonZeroUInt64" default_value="1073741824" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.9"},{"label": "1073741824"},{"label": "New setting."}]}]} />

Defines a bytes limit for a single inserted data file in delta lake.

<h2 id="delta_lake_insert_max_rows_in_data_file">
  delta\_lake\_insert\_max\_rows\_in\_data\_file
</h2>

<SettingsInfoBlock type="NonZeroUInt64" default_value="1000000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.9"},{"label": "1000000"},{"label": "New setting."}]}]} />

Defines a rows limit for a single inserted data file in delta lake.

<h2 id="delta_lake_log_metadata">
  delta\_lake\_log\_metadata
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.10"},{"label": "0"},{"label": "New setting."}]}]} />

Enables logging delta lake metadata files into system table.

<h2 id="delta_lake_reload_schema_for_consistency">
  delta\_lake\_reload\_schema\_for\_consistency
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.3"},{"label": "0"},{"label": "New setting to control whether DeltaLake reloads schema before each query for consistency."}]}]} />

If enabled, schema is reloaded from the DeltaLake metadata before each query execution to ensure
consistency between the schema used during query analysis and the schema used during execution.

<h2 id="delta_lake_snapshot_end_version">
  delta\_lake\_snapshot\_end\_version
</h2>

<SettingsInfoBlock type="Int64" default_value="-1" />

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

End version of delta lake snapshot to read. Value -1 means to read latest version (value 0 is a valid snapshot version).

<h2 id="delta_lake_snapshot_start_version">
  delta\_lake\_snapshot\_start\_version
</h2>

<SettingsInfoBlock type="Int64" default_value="-1" />

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

Start version of delta lake snapshot to read. Value -1 means to read latest version (value 0 is a valid snapshot version).

<h2 id="delta_lake_snapshot_version">
  delta\_lake\_snapshot\_version
</h2>

<SettingsInfoBlock type="Int64" default_value="-1" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.8"},{"label": "-1"},{"label": "New setting"}]}]} />

Version of delta lake snapshot to read. Value -1 means to read latest version (value 0 is a valid snapshot version).

<h2 id="delta_lake_throw_on_engine_predicate_error">
  delta\_lake\_throw\_on\_engine\_predicate\_error
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.8"},{"label": "0"},{"label": "New setting"}]}]} />

Enables throwing an exception if there was an error when analyzing scan predicate in delta-kernel.