The Ultimate Guide to High Availability with MariaDB

TABLE_MAP_EVENT

Used for row-based binary logging beginning (binlog_format=ROW or MIXED)

This event precedes each row operation event and maps a table definition to a number, where the table definition consists of database and table names.

  • Event Type is 19 (0x13)

Fields

Fixed data part:

Variable data part:

  • uint<1> Database name length.
  • string<NUL> The database name (null-terminated).
  • uint<1> Table name length.
  • string<NUL> The table name (null-terminated).
  • int<lenenc> The number of columns in the table.
  • byte<n> An array of 'n' column types, one byte per column.
  • int<lenenc> The length of the metadata block.
  • byte<n> The metadata block;
  • byte<n> Bit-field indicating whether each column can be NULL, one bit per column.
  • if (more_data_available)

Metadata block

The metadata block contains type specific metadata information for each column

TypeLengthDescription
MYSQL_TYPE_BLOB1Number of bytes for length: e.g. 4 bytes means length is stored in a 4 byte integer)
MYSQL_TYPE_DATETIME21Length of microseconds
MYSQL_TYPE_DECIMAL2Not in use anymore
MYSQL_TYPE_DOUBLE ,MYSQL_TYPE_FLOAT1length (4 or 8 bytes
MYSQL_TYPE_STRING21st byte contains type (MYSQL_TYPE_STRING, MYSQL_TYPE_ENUM, or MYSQL_TYPE_SET, 2nd byte contains length
MYSQL_TYPE_NEWDECIMAL2Precision, Scale
MYSQL_TYPE_TIME21Length of microseconds
MYSQL_TYPE_TIMESTAMP21Length of microseconds
MYSQL_TYPE_VARCHAR, MYSQL_TYPE_VAR_STRING2Defined varchar length. If the value is > 255, length is stored in 2 bytes, otherwise 1 byte

Optional metadata block

Optional metadata will be available if global server variable BINLOG_ROW_METADATA was set to values MIN or FULL.

The metadata block consists of one or more of the following blocks:

Optional metadata types:

NameValueModeDescription
SIGNEDNESS1MINData contains a bitmap indicating which integer columns are signed
DEFAULT_CHARSET2MINCharacter set of string columns, used if most columns have the same result. Columns with other character sets will follow as pair (column_index, collation number).
COLUMN_CHARSET3MINCharacter set of columns, used if columns have different character sets. Returned as a sequence of collation numbers.
COLUMN_NAME4FULLList of Column names, the first byte specifies the length of the column name
SET_STR_VALUE5FULLList of set values: First byte is the number of different values, followed by length/value pairs.
ENUM_STR_VALUE6FULLSame as SET_STR_VALUE. Since ENUM values might have up to 0xFFFF members, the number of values is a length encoded integer.
GEOMETRY_TYPE7FULLA sequence of bytes repesenting the type of GEOMETRY columns: 0 = GEOMETRY, 1 = POINT, 2 = LINESTRING, 3 = POLYGON, 4=MULTIPOINT, 5 = MULTILINESTRING, 6 = MULTIPOLYGON, 7 = GEOMETRYCOLLECTION
SIMPLE_PRIMARY_KEY8FULLA sequence of length encoded column indexes.
PRIMARY_KEY_WITH_PREFIX9FULLA sequence of length encoded column indexes and prefix lengths.
ENUM_AND_SET_DEFAULT_CHARSET10FULLThe default character set number used for ENUM and SET columns
ENUM_AND_SET_COLUMN_CHARSET11FULLCharacter set of ENUM and SET columns, used if these columns have different character sets. Returned as a sequence of collation numbers.

Example From mysqlbinlog

# at 847
#171206 13:43:00 server id 10124  end_log_pos 892 CRC32 0xbe3c6b05 	Table_map: `test`.`t4` mapped to number 33
# at 892

Complete Event

d4 e5 27 5a 13 8c 27 00  00 2d 00 00 00 7c 03 00  ..'Z..'..-...|..
00 00 00 21 00 00 00 00  00 01 00 04 74 65 73 74  ...!........test
00 02 74 34 00 01 03 01  01 05 6b 3c be           ..t4......k<.

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