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

Some times there are not output from requests.
settings.max_threads,
                max_added_blocks);
            if (!normal_result_ptr->error())
            {
                selected_candidate = &*minmax_count_projection_candidate;
                selected_candidate->merge_tree_normal_select_result_ptr = normal_result_ptr;
                min_sum_marks = query_info.minmax_count_projection_block.rows() + normal_result_ptr->marks();
            }
        }
    };
    
    if (minmax_count_projection_candidate)
        prepare_min_max_count_projection();
    
    if (!selected_candidate || !selected_candidate->complete)
        for (const auto & projection : metadata_snapshot->projections)
            add_projection_candidate(projection);
    
    if (!candidates.empty())
    {
        query_info.merge_tree_select_result_ptr = reader.estimateNumMarksToRead(
            parts,
            query_info.prewhere_info,
            analysis_result.required_columns,
            metadata_snapshot,
            metadata_snapshot,
            query_info,
            added_filter_nodes,
            query_context,
            settings.max_threads,