```
milovidov-desktop :) CREATE TABLE perf_lc_num(　        num UInt8,　        arr Array(LowCardinality(Int64)) default [num]　        ) ENGINE = TinyLog

CREATE TABLE perf_lc_num
(
    `num` UInt8,
    `arr` Array(LowCardinality(Int64)) DEFAULT [num]
)
ENGINE = TinyLog

Query id: e95f9a71-5795-4dea-8d80-4729fc8016b9

Ok.

0 rows in set. Elapsed: 0.002 sec. 

milovidov-desktop :) INSERT INTO perf_lc_num (num)
:-]         SELECT toUInt8(number)
:-]         FROM numbers(100000000)

INSERT INTO perf_lc_num (num) SELECT toUInt8(number)
FROM numbers(100000000)

Query id: 1101fd75-a545-4809-acb5-8afa2fae80c0


Received exception from server (version 20.13.1):
Code: 49. DB::Exception: Received from localhost:9000. DB::Exception: Got empty stream for DataTypeLowCardinality keys.: While executing SinkToOutputStream. 

0 rows in set. Elapsed: 0.045 sec. 

milovidov-desktop :) INSERT INTO perf_lc_num (num)　        SELECT toUInt8(number)　        FROM numbers(100000000)

INSERT INTO perf_lc_num (num) SELECT toUInt8(number)
FROM numbers(100000000)

Query id: 0ad8532a-5c6e-4590-84cd-7e00759d152d


Received exception from server (version 20.13.1):
Code: 49. DB::Exception: Received from localhost:9000. DB::Exception: Got empty stream for DataTypeLowCardinality keys.: While executing SinkToOutputStream. 

0 rows in set. Elapsed: 0.033 sec.
```

plain(disk->writeFile(data_path, max_compress_block_size, WriteMode::Append)),
            compressed(*plain, std::move(codec), max_compress_block_size)
        {
        }
        std::unique_ptr<WriteBuffer> plain;
        CompressedWriteBuffer compressed;
        void finalize()
        {
            compressed.next();
            plain->finalize();
        }
    };
    using FileStreams = std::map<String, std::unique_ptr<Stream>>;
    FileStreams streams;
    using SerializeState = IDataType::SerializeBinaryBulkStatePtr;
    using SerializeStates = std::map<String, SerializeState>;
    SerializeStates serialize_states;
    using WrittenStreams = std::set<String>;
    IDataType::OutputStreamGetter createStreamGetter(const String & name, WrittenStreams & written_streams);
    void writeData(const String & name, const IDataType & type, const IColumn & column, WrittenStreams & written_streams);
};
IDataType::OutputStreamGetter TinyLogBlockOutputStream::createStreamGetter(