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

Some times there are not output from requests.
{
    DataTypePtr partition_value_type = getPartitionValueType();
    return {
        ColumnWithTypeAndName(ColumnString::create(), std::make_shared<DataTypeString>(), "_part"),
        ColumnWithTypeAndName(ColumnString::create(), std::make_shared<DataTypeString>(), "_partition_id"),
        ColumnWithTypeAndName(ColumnUUID::create(), std::make_shared<DataTypeUUID>(), "_part_uuid"),
        ColumnWithTypeAndName(partition_value_type->createColumn(), partition_value_type, "_partition_value")};
}
Block MergeTreeData::getBlockWithVirtualPartColumns(const MergeTreeData::DataPartsVector & parts, bool one_part, bool ignore_empty) const
{
    auto block = getSampleBlockWithVirtualColumns();
    MutableColumns columns = block.mutateColumns();
    auto & part_column = columns[0];
    auto & partition_id_column = columns[1];
    auto & part_uuid_column = columns[2];
    auto & partition_value_column = columns[3];
    bool has_partition_value = typeid_cast<const ColumnTuple *>(partition_value_column.get());
    for (const auto & part_or_projection : parts)
    {
        if (ignore_empty && part_or_projection->isEmpty())
            continue;
        const auto * part = part_or_projection->isProjectionPart() ? part_or_projection->getParentPart() : part_or_projection.get();
        part_column->insert(part->name);
        partition_id_column->insert(part->info.partition_id);
        part_uuid_column->insert(part->uuid);
        Tuple tuple(part->partition.value.begin(), part->partition.value.end());
        if (has_partition_value)
            partition_value_column->insert(tuple);
        if (one_part)