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

Some times there are not output from requests.
const MergeTreePartInfo & part_info,
    DataPartState state,
    DataPartsLock & ) const
{
    PartHierarchy result;
    
    auto it_middle = data_parts_by_state_and_info.lower_bound(DataPartStateAndInfo{state, part_info});
    auto committed_parts_range = getDataPartsStateRange(state);
    
    DataPartIteratorByStateAndInfo begin = it_middle;
    while (begin != committed_parts_range.begin())
    {
        auto prev = std::prev(begin);
        if (!part_info.contains((*prev)->info))
        {
            if ((*prev)->info.contains(part_info))
            {
                result.covering_parts.push_back(*prev);
            }
            else if (!part_info.isDisjoint((*prev)->info))
            {
                result.intersected_parts.push_back(*prev);
            }
            break;
        }
        begin = prev;