```
create table test_lc(a LowCardinality(String)) Engine = MergeTree order by tuple();

insert into test_lc values ('abcd');

select * from test_lc format Parquet;

Exception on client:
Code: 50. DB::Exception: The type "LowCardinality" of a column "a" is not supported for conversion into a Parquet data format

Connecting to localhost:9000 as user default.
Connected to ClickHouse server version 20.3.12 revision 54433.
```

Shorter version of the test:
```
select toLowCardinality('abcd') format Parquet;

Exception on client:
Code: 50. DB::Exception: The type "LowCardinality" of a column "toLowCardinality('abcd')" is not supported for conversion into a Parquet data format

Connecting to localhost:9000 as user default.
Connected to ClickHouse server version 20.3.12 revision 54433.
```

<s>P.S. Insert works ok.</s>
```
# clickhouse-client --query="select 'ab' as a format Parquet" | clickhouse-client --query="insert into test_lc format Parquet"
```

UPD: not ok with `LowCardinality(Nullable(String))` (see comment). 
#    undef DISPATCH
                    
                    
                    
                default:
                    throw Exception
                    {
                            "Unsupported " + format_name + " type \"" + arrow_column->type()->name() + "\" of an input column \""
                            + header_column.name + "\"",
                            ErrorCodes::UNKNOWN_TYPE
                    };
            }
            if (column.type->isNullable())
            {
                MutableColumnPtr null_bytemap = DataTypeUInt8().createColumn();
                fillByteMapFromArrowColumn(arrow_column, null_bytemap);
                column.column = ColumnNullable::create(std::move(read_column), std::move(null_bytemap));
            }
            else
                column.column = std::move(read_column);
            column.column = castColumn(column, column_type);
            column.type = column_type;
            num_rows = column.column->size();
            columns_list.push_back(std::move(column.column));
        }
        res.setColumns(columns_list, num_rows);
    }
}
#endif