RawBLOB

Description {#description}

The RawBLOB formats reads all input data to a single value. It is possible to parse only a table with a single field of type String or similar. The result is output as a binary format without delimiters and escaping. If more than one value is output, the format is ambiguous, and it will be impossible to read the data back.

Raw formats comparison {#raw-formats-comparison}

Below is a comparison of the formats RawBLOB and TabSeparatedRaw.

RawBLOB:

• data is output in binary format, no escaping;
• there are no delimiters between values;
• no new-line at the end of each value.

TabSeparatedRaw:

• data is output without escaping;
• the rows contain values separated by tabs;
• there is a line feed after the last value in every row.

The following is a comparison of the RawBLOB and RowBinary formats.

RawBLOB:

• String fields are output without being prefixed by length.

RowBinary:

• String fields are represented as length in varint format (unsigned [LEB128] (https://en.wikipedia.org/wiki/LEB128)), followed by the bytes of the string.

When empty data is passed to the RawBLOB input, ClickHouse throws an exception:

Code: 108. DB::Exception: No data to insert

Example usage {#example-usage}

$ clickhouse-client --query "CREATE TABLE {some_table} (a String) ENGINE = Memory;"
$ cat {filename} | clickhouse-client --query="INSERT INTO {some_table} FORMAT RawBLOB"
$ clickhouse-client --query "SELECT * FROM {some_table} FORMAT RawBLOB" | md5sum

f9725a22f9191e064120d718e26862a9  -

Format settings {#format-settings}