ROWS_EVENT_V1/V2, ROWS_COMPRESSED_EVENT_V1

A ROWS_EVENT_V1 is written for row-based replication if data is inserted, deleted or updated.

A ROWS_EVENT (version 2) is written for row based replication if data is inserted, deleted or updated. MariaDB Server doesn't send version 2 row events.

Event types

Header

• WRITE_ROWS_EVENT_V1: Event Type is 23 (0x17).

• UPDATE_ROWS_EVENT_V1: Event Type is 24 (0x18).

• DELETE_ROWS_EVENT_V1: Event Type is 25 (0x19).

Fields

• The table id.

• Flags.

• If rows_event is version 2:

  • Extra data length.

Table id

Table id refers to a table defined by . The special value 0xFFFFFF should have "end of statement flag" (0x0001) set and indicates that table maps can be freed.

Flags

Extra data length (version 2)

The length of extra data.

Extra data (version 2)

Extra data, length is extra data length -2.

Column Data Formats

The row data is stored in a packed format where each field is encoded in a particular format. The encoding is almost identical to the binary protocol but there are a few differences.

The field metadata is stored in the metadata block of the . The metadata is required to decode the events. The following list shows number of bytes a field uses from the metadata block.

• 2 bytes

  • MYSQL_TYPE_BIT

  • MYSQL_TYPE_ENUM

  • MYSQL_TYPE_SET

The types that aren't listed here do not store data in the metadata block.

Simple Types

MYSQL_TYPE_BLOB and other blob types

Stored as a length-encoded string where the string is preceded by a variable-sized integer that stores the length of the blob. The size of the preceding integer in bytes is stored as a one byte integer in the table metadata that is a part of the table map event.

For example, if the value 4 is stored in the table metadata, the length is stored as a 4 byte integer (for instance, uint32_t) followed by the data.

The exact column_type can be determined by the metadata length:

MYSQL_TYPE_STRING, MYSQL_TYPE_SET and MYSQL_TYPE_ENUM

Stored as a fixed-length string with the length of the string stored in the second byte of the table metadata. All three of these types are stored as MYSQL_TYPE_STRING in the binlog and the real type of the field is stored in the first byte of the metadata.

MYSQL_TYPE_VARCHAR and other variable length string types

Stored as a length-encoded string where the string is preceded by a variable-sized integer that stores the length of the string. The field length is stored as a two byte integer in the table metadata.

If the field length is larger than 255, the string length is stored as a two byte integer. If the value is equal to or less than 255, the string length is stored as a one byte integer.

MYSQL_TYPE_DATETIME

This field type is only used in MariaDB if the global variable mysql56_temporal_format is set to OFF. Stored as an 8 byte value with the values stored as multiples of 100. This means that the stored value is in the format YYYYMMDDHHMMSS , and can be extracted by repeatedly calculating the remainder of dividing the value by 100 and dividing the value by 100. The following pseudo-code demonstrates extracting the value.

MYSQL_TYPE_TIME

This field type is only used in MariaDB if the global variable mysql56_temporal_format is set to OFF. Stored as a 3 byte value with the values stored as multiples of 100. This means that the stored value is in the format HHMMSS and can be extracted in the same way a MYSQL_TYPE_DATETIME is extracted. The following pseudo-code demonstrates extracting the value.

MYSQL_TYPE_DATETIME2

Stored as 4-byte value The number of decimals for the fractional part is stored in the table metadata as a one byte value. The number of bytes that follow the 5 byte datetime value can be calculated with the following formula: (decimals + 1) / 2 .

MYSQL_TYPE_TIME2

Stored as 3-byte value. The number of decimals for the fractional part is stored in the table metadata as a one byte value. The number of bytes that follow the 3 byte time value can be calculated with the following formula: (decimals + 1) / 2 .

MYSQL_TYPE_TIMESTAMP2

Stored as a 4 byte UNIX timestamp (number of seconds since 00:00, Jan 1 1970 UTC) followed by the fractional second parts. The number of decimals for the fractional part is stored in the table metadata as a one byte value. The number of bytes that follow the 4 byte timestamp can be calculated with the following formula: (decimals + 1) / 2

Microseconds for MYSQL_TYPE_DATETIME2, MYSQL_TYPE_TIME2 , and MYSQL_TYPE_TIMESTAMP .

MYSQL_TYPE_DATE

Stored as a 3 byte value where bits 1 to 5 store the day, bits 6 to 9 store the month and the remaining bits store the year.

MYSQL_TYPE_TIMESTAMP

Stored as a 4 byte UNIX timestamp (number of seconds since 00:00, Jan 1 1970 UTC).

Example From mysqlbinlog Utility, CRC32

Example Event as Written to the Binlog File

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