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

Some times there are not output from requests.
{
    const auto settings = getSettings();
    bool has_zero_copy_parts = false;
    if (supportsReplication() && settings->allow_remote_fs_zero_copy_replication)
    {
        has_zero_copy_parts = std::any_of(
            parts_to_remove.begin(), parts_to_remove.end(),
            [] (const auto & data_part) { return data_part->isStoredOnRemoteDiskWithZeroCopySupport(); }
        );
    }
    if (parts_to_remove.size() > 1
        && settings->max_part_removal_threads > 1
        && parts_to_remove.size() > settings->concurrent_part_removal_threshold
        && !has_zero_copy_parts) 
    {
        
        size_t num_threads = std::min<size_t>(settings->max_part_removal_threads, parts_to_remove.size());
        std::mutex part_names_mutex;
        ThreadPool pool(num_threads);