```
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;
```
part->getFileNamesWithoutChecksums(),
            data_path_in_backup,
            backup_entries_from_part,
            make_temporary_hard_links,
            &temp_dirs);
        auto projection_parts = part->getProjectionParts();
        for (const auto & [projection_name, projection_part] : projection_parts)
        {
            projection_part->getDataPartStorage().backup(
                projection_part->checksums,
                projection_part->getFileNamesWithoutChecksums(),
                fs::path{data_path_in_backup} / part->name,
                backup_entries_from_part,
                make_temporary_hard_links,
                &temp_dirs);
        }
        if (hold_storage_and_part_ptrs)
        {
            
            
            auto storage_and_part = std::make_pair(shared_from_this(), part);
            if (hold_table_lock)
                wrapBackupEntriesWith(backup_entries_from_part, std::make_pair(storage_and_part, table_lock));
            else
                wrapBackupEntriesWith(backup_entries_from_part, storage_and_part);
        }
        insertAtEnd(backup_entries, std::move(backup_entries_from_part));
    }
    return backup_entries;
}