```
CREATE TABLE t (x UInt8, PROJECTION p (SELECT x GROUP BY x)) ENGINE = MergeTree ORDER BY ();
INSERT INTO t VALUES (0);

SET group_by_overflow_mode = 'any', max_rows_to_group_by = 1000, totals_mode = 'after_having_auto';
SELECT x FROM t GROUP BY x WITH TOTALS;
```
const String & name, const MutableDataPartStoragePtr & data_part_storage, const IMergeTreeDataPart * parent_part) const
{
    return createPart(name, MergeTreePartInfo::fromPartName(name, format_version), data_part_storage, parent_part);
}
MergeTreeData::MutableDataPartPtr MergeTreeData::createPart(
    const String & name, const MergeTreePartInfo & part_info,
    const MutableDataPartStoragePtr & data_part_storage, const IMergeTreeDataPart * parent_part) const
{
    MergeTreeDataPartType type;
    auto mrk_ext = MergeTreeIndexGranularityInfo::getMarksExtensionFromFilesystem(*data_part_storage);
    if (mrk_ext)
    {
        type = MarkType(*mrk_ext).part_type;
    }
    else
    {
        
        type = choosePartTypeOnDisk(0, 0);
    }
    return createPart(name, type, part_info, data_part_storage, parent_part);
}
void MergeTreeData::changeSettings(