```
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;
```
{
    if (disk->getLastModified(directory_path).epochTime() >= threshold)
        return false;
    for (auto it = disk->iterateDirectory(directory_path); it->isValid(); it->next())
        if (disk->getLastModified(it->path()).epochTime() >= threshold)
            return false;
    return true;
}
size_t MergeTreeData::clearOldTemporaryDirectories(size_t custom_directories_lifetime_seconds, const NameSet & valid_prefixes)
{
    
    std::unique_lock lock(clear_old_temporary_directories_mutex, std::defer_lock);
    if (!lock.try_lock())
        return 0;
    const auto settings = getSettings();
    time_t current_time = time(nullptr);
    ssize_t deadline = current_time - custom_directories_lifetime_seconds;
    size_t cleared_count = 0;
    
    for (const auto & disk : getDisks())
    {
        if (disk->isBroken())
            continue;
        for (auto it = disk->iterateDirectory(relative_data_path); it->isValid(); it->next())
        {
            const std::string & basename = it->name();
            bool start_with_valid_prefix = false;
            for (const auto & prefix : valid_prefixes)
            {
                if (startsWith(basename, prefix))