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

Some times there are not output from requests.
original_active_part->force_keep_shared_data = true;
            }
            modifyPartState(original_active_part, DataPartState::DeleteOnDestroy);
            data_parts_indexes.erase(active_part_it);
            auto part_it = data_parts_indexes.insert(part_copy).first;
            modifyPartState(part_it, DataPartState::Active);
            ssize_t diff_bytes = part_copy->getBytesOnDisk() - original_active_part->getBytesOnDisk();
            ssize_t diff_rows = part_copy->rows_count - original_active_part->rows_count;
            increaseDataVolume(diff_bytes, diff_rows,  0);
            
            
            lockSharedData(*part_copy);
            preparePartForRemoval(original_active_part)->writeDeleteOnDestroyMarker();
            return;
        }
    }
    throw Exception("Cannot swap part '" + part_copy->name + "', no such active part.", ErrorCodes::NO_SUCH_DATA_PART);
}
MergeTreeData::DataPartPtr MergeTreeData::getActiveContainingPart(const MergeTreePartInfo & part_info) const
{
    auto lock = lockParts();
    return getActiveContainingPart(part_info, DataPartState::Active, lock);
}
MergeTreeData::DataPartPtr MergeTreeData::getActiveContainingPart(const String & part_name) const
{
    auto part_info = MergeTreePartInfo::fromPartName(part_name, format_version);
    return getActiveContainingPart(part_info);
}
MergeTreeData::DataPartsVector MergeTreeData::getVisibleDataPartsVectorInPartition(ContextPtr local_context, const String & partition_id) const