Statistics
https://play.clickhouse.com/play?user=play#c2VsZWN0IAp0b1N0YXJ0T2ZIb3VyKGNoZWNrX3N0YXJ0X3RpbWUpIGFzIGQsCmNvdW50KCksICBncm91cFVuaXFBcnJheShwdWxsX3JlcXVlc3RfbnVtYmVyKSwgIGFueShyZXBvcnRfdXJsKQpmcm9tIGNoZWNrcyB3aGVyZSAnMjAyMi0wNi0wMScgPD0gY2hlY2tfc3RhcnRfdGltZSBhbmQgdGVzdF9uYW1lIGxpa2UgJyUwMjQ5MV9wYXJ0X2xvZ19oYXNfdGFibGVfdXVpZCUnIGFuZCB0ZXN0X3N0YXR1cyBpbiAoJ0ZBSUwnLCAnRkxBS1knKSBncm91cCBieSBkIG9yZGVyIGJ5IGQgZGVzYw==

Some times there are not output from requests.
}
        need_remove_parts_in_order = has_zero_copy_disk;
    }
    std::vector<DataPartIteratorByStateAndInfo> parts_to_delete;
    std::vector<MergeTreePartInfo> skipped_parts;
    auto has_skipped_mutation_parent = [&skipped_parts, need_remove_parts_in_order] (const DataPartPtr & part)
    {
        if (!need_remove_parts_in_order)
            return false;
        for (const auto & part_info : skipped_parts)
            if (part->info.isMutationChildOf(part_info))
                return true;
        return false;
    };
    auto time_now = time(nullptr);
    {
        auto parts_lock = lockParts();
        auto outdated_parts_range = getDataPartsStateRange(DataPartState::Outdated);
        for (auto it = outdated_parts_range.begin(); it != outdated_parts_range.end(); ++it)
        {
            const DataPartPtr & part = *it;
            
            if (!part->version.canBeRemoved())
            {
                skipped_parts.push_back(part->info);
                continue;
            }
            
            if (!part.unique())
            {