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WL#4078: Document binary format of binlog entries 

Documented Table_map_log_event and packed integer format. Improved
other documentation. No change outside comments.


sql/log_event.h:
  Documented Table_map_log_event and packed integer format. Improved
  other documentation. No change outside comments.
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sql/log_event.h
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......@@ -667,34 +667,35 @@ typedef struct st_print_event_info
@section Log_event_binary_format Binary Format
Any Log_event saved on disk consists of the following three
Any @c Log_event saved on disk consists of the following three
components.
@li Common-Header
@li Post-Header
@li Body
* Common-Header
* Post-Header
* Body
The Common-Header, documented below, always has the same form and
length within one version of MySQL. Each event type specifies a
form and length of the Post-Header common to all events of the type.
The Body may be of different form and length even for different
events of the same type. The binary formats of Post-Header and Body
are documented separately in each subclass. The binary format of
Common-Header is as follows.
The Common-Header, documented in the table @ref Table_common_header
"below", always has the same form and length within one version of
MySQL. Each event type specifies a form and length of the
Post-Header common to all events of the type. The Body may be of
different form and length even for different events of the same
type. The binary formats of Post-Header and Body are documented
separately in each subclass. The binary format of Common-Header is
as follows.
<table>
<caption>Common-Header</caption>
<tr>
<th>Name</th>
<th>Format<br/></th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
<td>timestamp</td>
<td>4 byte unsigned integer</td>
<td>The number of seconds since 1970.
<td>The time when the query started, in seconds since 1970.
</td>
</tr>
......@@ -705,14 +706,14 @@ typedef struct st_print_event_info
</tr>
<tr>
<td>master_id</td>
<td>4 byte integer</td>
<td>server_id</td>
<td>4 byte unsigned integer</td>
<td>Server ID of the server that created the event.</td>
</tr>
<tr>
<td>total_size</td>
<td>4 byte integer</td>
<td>4 byte unsigned integer</td>
<td>The total size of this event, in bytes. In other words, this
is the sum of the sizes of Common-Header, Post-Header, and Body.
</td>
......@@ -720,9 +721,12 @@ typedef struct st_print_event_info
<tr>
<td>master_position</td>
<td>4 byte integer</td>
<td>4 byte unsigned integer</td>
<td>The position of the next event in the master binary log, in
bytes from the beginning of the file.
bytes from the beginning of the file. In a binlog that is not a
relay log, this is just the position of the next event, in bytes
from the beginning of the file. In a relay log, this is
the position of the next event in the master's binlog.
</td>
</tr>
......@@ -736,13 +740,55 @@ typedef struct st_print_event_info
Summing up the numbers above, we see that the total size of the
common header is 19 bytes.
@subsection Log_event_endianness_and_string_formats Endianness and String Formats
@subsection Log_event_format_of_atomic_primitives Format of Atomic Primitives
- All numbers, whether they are 16-, 24-, 32-, or 64-bit numbers,
are stored in little endian, i.e., the least significant byte first,
unless otherwise specified.
@anchor packed_integer
- Some events use a special format for efficient representation of
unsigned integers, called Packed Integer. A Packed Integer has the
capacity of storing up to 8-byte integers, while small integers
still can use 1, 3, or 4 bytes. The first byte indicates how many
bytes are used by the integer, according to the following table:
<table>
<caption>Format of Packed Integer</caption>
<tr>
<th>First byte</th>
<th>Format</th>
</tr>
<tr>
<td>0-250</td>
<td>The first byte is the number (in range 0-250), and no more
bytes are used.</td>
</tr>
<tr>
<td>252</td>
<td>Two more bytes are used. The number is in the range
251-0xffff.</td>
</tr>
All numbers, whether they are 16-, 32-, or 64-bit, are stored in
little endian, i.e., the least significant byte first.
<tr>
<td>253</td>
<td>Three more bytes are used. The number is in the range
0xffff-0xffffff.</td>
</tr>
Strings are stored in various formats. The format of each string is
documented separately.
<tr>
<td>254</td>
<td>Eight more bytes are used. The number is in the range
0xffffff-0xffffffffffffffff.</td>
</tr>
</table>
- Strings are stored in various formats. The format of each string
is documented separately.
*/
class Log_event
{
......@@ -1123,7 +1169,8 @@ protected:
/**
@class Query_log_event
Logs SQL queries.
A @c Query_log_event is created for each query that modifies the
database, unless the query is logged row-based.
@section Query_log_event_binary_format Binary format
......@@ -1134,60 +1181,49 @@ protected:
<tr>
<th>Name</th>
<th>Size<br/></th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
<td>slave_proxy_id</td>
<td>4 byte unsigned integer</td>
<td>An integer identifying the client thread, which is unique on
the server. (Note, however, that two threads on different servers
may have the same slave_proxy_id.) This is used when a client
thread creates a temporary table. Temporary tables are local to
the client, and the slave_proxy_id is used to distinguish
temporary tables belonging to different clients.
<td>An integer identifying the client thread that issued the
query. The id is unique per server. (Note, however, that two
threads on different servers may have the same slave_proxy_id.)
This is used when a client thread creates a temporary table local
to the client. The slave_proxy_id is used to distinguish
temporary tables that belong to different clients.
</td>
</tr>
<tr>
<td>exec_time</td>
<td>4 byte integer</td>
<td>???TODO</td>
<td>4 byte unsigned integer</td>
<td>The time from when the query started to when it was logged in
the binlog, in seconds.</td>
</tr>
<tr>
<td>db_len</td>
<td>1 byte integer</td>
<td>The length of the name of the currently selected
database.
</td>
<td>The length of the name of the currently selected database.</td>
</tr>
<tr>
<td>error_code</td>
<td>2 byte integer</td>
<td>2 byte unsigned integer</td>
<td>Error code generated by the master. If the master fails, the
slave will fail with the same error code, except for the error
codes ER_DB_CREATE_EXISTS==1007 and ER_DB_DROP_EXISTS==1008.
codes ER_DB_CREATE_EXISTS == 1007 and ER_DB_DROP_EXISTS == 1008.
</td>
</tr>
<tr>
<td>status_vars_len</td>
<td>2 byte integer</td>
<td>2 byte unsigned integer</td>
<td>The length of the status_vars block of the Body, in bytes. See
<a href="#query_log_event_status_vars">below</a>.
</td>
</tr>
<tr>
<td>Post-Header-For-Derived</td>
<td>0 bytes</td>
<td>This field is only written by the subclass
Execute_load_query_log_event. In this base class, it takes 0
bytes. See separate documentation for
Execute_load_query_log_event.
@ref query_log_event_status_vars "below".
</td>
</tr>
</table>
......@@ -1199,19 +1235,19 @@ protected:
<tr>
<th>Name</th>
<th>Size<br/></th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
<td><a name="query_log_event_status_vars" /> status_vars</td>
<td>variable length</td>
<td>@anchor query_log_event_status_vars status_vars</td>
<td>status_vars_len bytes</td>
<td>Zero or more status variables. Each status variable consists
of one byte identifying the variable stored, followed by the value
of the variable. The possible variables are listed separately in
the table below. MySQL always writes events in the order defined
below; however, it is capable of reading them in any order.
</td>
the table @ref Table_query_log_event_status_vars "below". MySQL
always writes events in the order defined below; however, it is
capable of reading them in any order. </td>
</tr>
<tr>
......@@ -1237,13 +1273,14 @@ protected:
The following table lists the status variables that may appear in
the status_vars field.
@anchor Table_query_log_event_status_vars
<table>
<caption>Status variables for Query_log_event</caption>
<tr>
<th>Status variable</th>
<th>1-byte identifier</th>
<th>Size<br/></th>
<th>1 byte identifier</th>
<th>Format</th>
<th>Description</th>
</tr>
......@@ -1251,13 +1288,13 @@ protected:
<td>flags2</td>
<td>Q_FLAGS2_CODE == 0</td>
<td>4 byte bitfield</td>
<td>The flags in thd->options, binary AND-ed with
OPTIONS_WRITTEN_TO_BIN_LOG. The thd->options bitfield contains
options for SELECT. OPTIONS_WRITTEN identifies those options that
need to be written to the binlog (not all do). Specifically,
OPTIONS_WRITTEN_TO_BIN_LOG equals (OPTION_AUTO_IS_NULL |
OPTION_NO_FOREIGN_KEY_CHECKS | OPTION_RELAXED_UNIQUE_CHECKS |
OPTION_NOT_AUTOCOMMIT), or 0x0c084000 in hex.
<td>The flags in @c thd->options, binary AND-ed with @c
OPTIONS_WRITTEN_TO_BIN_LOG. The @c thd->options bitfield contains
options for "SELECT". @c OPTIONS_WRITTEN identifies those options
that need to be written to the binlog (not all do). Specifically,
@c OPTIONS_WRITTEN_TO_BIN_LOG equals (@c OPTION_AUTO_IS_NULL | @c
OPTION_NO_FOREIGN_KEY_CHECKS | @c OPTION_RELAXED_UNIQUE_CHECKS |
@c OPTION_NOT_AUTOCOMMIT), or 0x0c084000 in hex.
These flags correspond to the SQL variables SQL_AUTO_IS_NULL,
FOREIGN_KEY_CHECKS, UNIQUE_CHECKS, and AUTOCOMMIT, documented in
......@@ -1271,8 +1308,8 @@ protected:
<tr>
<td>sql_mode</td>
<td>Q_SQL_MODE_CODE == 1</td>
<td>8 byte integer</td>
<td>The sql_mode variable. See the section "SQL Modes" in the
<td>8 byte bitfield</td>
<td>The @c sql_mode variable. See the section "SQL Modes" in the
MySQL manual, and see mysql_priv.h for a list of the possible
flags. Currently (2007-10-04), the following flags are available:
<pre>
......@@ -1310,10 +1347,10 @@ protected:
MODE_PAD_CHAR_TO_FULL_LENGTH==0x80000000
</pre>
All these flags are replicated from the server. However, all
flags except MODE_NO_DIR_IN_CREATE are honored by the slave; the
slave always preserves its old value of MODE_NO_DIR_IN_CREATE.
For a rationale, see comment in Query_log_event::do_apply_event in
log_event.cc.
flags except @c MODE_NO_DIR_IN_CREATE are honored by the slave;
the slave always preserves its old value of @c
MODE_NO_DIR_IN_CREATE. For a rationale, see comment in
@c Query_log_event::do_apply_event in @c log_event.cc.
This field is always written to the binlog.
</td>
......@@ -1327,7 +1364,7 @@ protected:
</td>
<td>Stores the client's current catalog. Every database belongs
to a catalog, the same way that every table belongs to a
database. Currently, there is only one catalog, 'std'.
database. Currently, there is only one catalog, "std".
This field is written if the length of the catalog is > 0;
otherwise it is not written.
......@@ -1343,7 +1380,7 @@ protected:
auto_increment_offset, in that order. For more information, see
"System variables" in the MySQL manual.
This field is written if auto_increment>1; otherwise it is not
This field is written if auto_increment > 1. Otherwise, it is not
written.
</td>
</tr>
......@@ -1351,14 +1388,14 @@ protected:
<tr>
<td>charset</td>
<td>Q_CHARSET_CODE == 4</td>
<td>three 2-byte unsigned integers (i.e., 6 bytes)</td>
<td>three 2 byte unsigned integers, totally 2+2+2=6 bytes</td>
<td>The three variables character_set_client,
collation_connection, and collation_server, in that order.
`character_set_client' is a code identifying the character set and
character_set_client is a code identifying the character set and
collation used by the client to encode the query.
`collation_connection' identifies the character set and collation
collation_connection identifies the character set and collation
that the master converts the query to when it receives it; this is
useful when comparing literal strings. `collation_server' is the
useful when comparing literal strings. collation_server is the
default character set and collation used when a new database is
created.
......@@ -1396,9 +1433,9 @@ protected:
<td>Q_LC_TIME_NAMES_CODE == 7</td>
<td>2 byte integer</td>
<td>A code identifying a table of month and day names. The
mapping from codes to languages is defined in sql_locale.cc.
mapping from codes to languages is defined in @c sql_locale.cc.
This field is written if it is != 0, i.e., if the locale is not
This field is written if it is not 0, i.e., if the locale is not
en_US.
</td>
</tr>
......@@ -1409,14 +1446,14 @@ protected:
<td>2 byte integer</td>
<td>The value of the collation_database system variable (in the
source code stored in thd->variables.collation_database), which
source code stored in @c thd->variables.collation_database), which
holds the code for a (character set, collation) pair as described
above (see Q_CHARSET_CODE).
`collation_database' was used in old versions (???WHEN). Its
value was loaded when issuing a "use db" command and could be
changed by issuing a "SET collation_database=xxx" command. It
used to affect the "LOAD DATA INFILE" and "CREATE TABLE" commands.
collation_database was used in old versions (???WHEN). Its value
was loaded when issuing a "use db" query and could be changed by
issuing a "SET collation_database=xxx" query. It used to affect
the "LOAD DATA INFILE" and "CREATE TABLE" commands.
In newer versions, "CREATE TABLE" has been changed to take the
character set from the database of the created table, rather than
......@@ -1433,17 +1470,17 @@ protected:
@subsection Query_log_event_notes_on_previous_versions Notes on Previous Versions
@li Status vars were introduced in version 5.0. To read earlier
* Status vars were introduced in version 5.0. To read earlier
versions correctly, check the length of the Post-Header.
@li The status variable Q_CATALOG_CODE == 2 existed in MySQL 5.0.x,
* The status variable Q_CATALOG_CODE == 2 existed in MySQL 5.0.x,
where 0<=x<=3. It was identical to Q_CATALOG_CODE, except that the
string had a trailing '\0'. The '\0' was removed in 5.0.4 since it
was redundant (the string length is stored before the string). The
Q_CATALOG_CODE will never be written by a new master, but can still
be understood by a new slave.
@li See Q_CHARSET_DATABASE_NUMBER in the table above.
* See Q_CHARSET_DATABASE_NUMBER in the table above.
*/
class Query_log_event: public Log_event
......@@ -1576,7 +1613,8 @@ public: /* !!! Public in this patch to allow old usage */
/**
@class Muted_query_log_event
Pretends to log SQL queries, but doesn't actually do so.
Pretends to log SQL queries, but doesn't actually do so. This is
used internally only and never written to any binlog.
@section Muted_query_log_event_binary_format Binary Format
......@@ -1603,7 +1641,7 @@ public:
@class Slave_log_event
Note that this class is currently not used at all; no code writes a
Slave_log_event (though some code in repl_failsafe.cc reads
@c Slave_log_event (though some code in @c repl_failsafe.cc reads @c
Slave_log_event). So it's not a problem if this code is not
maintained.
......@@ -1617,7 +1655,7 @@ public:
<tr>
<th>Name</th>
<th>Size<br/></th>
<th>Format</th>
<th>Description</th>
</tr>
......@@ -1717,26 +1755,27 @@ private:
<tr>
<th>Name</th>
<th>Size<br/></th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
<td>slave_proxy_id</td>
<td>4 byte unsigned integer</td>
<td>An integer identifying the client thread, which is unique on
the server. (Note, however, that the same slave_proxy_id may
appear on different servers.) This is used when a client thread
creates a temporary table. Temporary tables are local to the
client, and the slave_proxy_id is used to distinguish temporary
tables belonging to different clients.
<td>An integer identifying the client thread that issued the
query. The id is unique per server. (Note, however, that two
threads on different servers may have the same slave_proxy_id.)
This is used when a client thread creates a temporary table local
to the client. The slave_proxy_id is used to distinguish
temporary tables that belong to different clients.
</td>
</tr>
<tr>
<td>exec_time</td>
<td>4 byte unsigned integer</td>
<td>???TODO</td>
<td>The time from when the query started to when it was logged in
the binlog, in seconds.</td>
</tr>
<tr>
......@@ -1773,7 +1812,7 @@ private:
<tr>
<th>Name</th>
<th>Size<br/></th>
<th>Format</th>
<th>Description</th>
</tr>
......@@ -1813,7 +1852,7 @@ private:
<li> In the old format, we know that each string has length 0 or
1. Therefore, only the first byte of each string is stored. The
order of the strings is the same as in the new format. These five
bytes are followed by the same 1-byte bitfield as in the new
bytes are followed by the same 1 byte bitfield as in the new
format. Finally, a 1 byte bitfield called empty_flags is stored.
The low 5 bits of empty_flags indicate which of the five strings
have length 0. For each of the following flags that is set, the
......@@ -1831,7 +1870,7 @@ private:
<tr>
<td>field_lens</td>
<td>num_fields 1-byte unsigned integers</td>
<td>num_fields 1 byte unsigned integers</td>
<td>An array of num_fields integers representing the length of
each field in the query. (num_fields is from the Post-Header).
</td>
......@@ -1992,11 +2031,13 @@ extern char server_version[SERVER_VERSION_LENGTH];
Start_log_event_v3 is the Start_log_event of binlog format 3 (MySQL 3.23 and
4.x).
Format_description_log_event derives from Start_log_event_v3; it is the
Start_log_event of binlog format 4 (MySQL 5.0), that is, the event that
describes the other events' header/postheader lengths. This event is sent by
MySQL 5.0 whenever it starts sending a new binlog if the requested position
is >4 (otherwise if ==4 the event will be sent naturally).
Format_description_log_event derives from Start_log_event_v3; it is
the Start_log_event of binlog format 4 (MySQL 5.0), that is, the
event that describes the other events' Common-Header/Post-Header
lengths. This event is sent by MySQL 5.0 whenever it starts sending
a new binlog if the requested position is >4 (otherwise if ==4 the
event will be sent naturally).
@section Start_log_event_v3_binary_format Binary Format
*/
......@@ -2150,7 +2191,9 @@ protected:
/**
@class Intvar_log_event
Logs special variables related to auto_increment values.
An Intvar_log_event will be created just before a Query_log_event,
if the query uses one of the variables LAST_INSERT_ID or INSERT_ID.
Each Intvar_log_event holds the value of one of these variables.
@section Intvar_log_event_binary_format Binary Format
......@@ -2161,12 +2204,12 @@ protected:
<tr>
<th>Name</th>
<th>Size<br/></th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
<td>Type</td>
<td>type</td>
<td>1 byte enumeration</td>
<td>One byte identifying the type of variable stored. Currently,
two identifiers are supported: LAST_INSERT_ID_EVENT==1 and
......@@ -2182,7 +2225,6 @@ protected:
</table>
*/
class Intvar_log_event: public Log_event
{
public:
......@@ -2228,15 +2270,34 @@ private:
written in 4.1.1 for PASSWORD() (but the fact that it is written is just a
waste, it does not cause bugs).
The state of the random number generation consists of 128 bits,
which are stored internally as two 64-bit numbers.
@section Rand_log_event_binary_format Binary Format
This event type has no Post-Header. The Body of this event type has
two components:
@li seed1 (8 bytes): 64 bit random seed1.
@li seed2 (8 bytes): 64 bit random seed2.
<table>
<caption>Post-Header for Intvar_log_event</caption>
The state of the random number generation consists of 128 bits,
which are stored internally as two 64-bit numbers.
<tr>
<th>Name</th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
<td>seed1</td>
<td>8 byte unsigned integer</td>
<td>64 bit random seed1.</td>
</tr>
<tr>
<td>seed2</td>
<td>8 byte unsigned integer</td>
<td>64 bit random seed2.</td>
</tr>
</table>
*/
class Rand_log_event: public Log_event
......@@ -2423,14 +2484,14 @@ private:
<tr>
<th>Name</th>
<th>Size<br/></th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
<td>pos</td>
<td>position</td>
<td>8 byte integer</td>
<td>???TODO</td>
<td>The position within the binlog to rotate to.</td>
</tr>
</table>
......@@ -2442,17 +2503,17 @@ private:
<tr>
<th>Name</th>
<th>Size<br/></th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
<td>new_log_ident</td>
<td>new_log</td>
<td>variable length string without trailing zero, extending to the
end of the event (determined by the length field of the
Common-Header)
</td>
<td>???TODO</td>
<td>Name of the binlog to rotate to.</td>
</tr>
</table>
......@@ -2841,10 +2902,316 @@ char *str_to_hex(char *to, const char *from, uint len);
/**
@class Table_map_log_event
Create a mapping from a (database name, table name) couple to a table
identifier (an integer number).
In row-based mode, every row operation event is preceded by a
Table_map_log_event which maps a table definition to a number. The
table definition consists of database name, table name, and column
definitions.
@section Table_map_log_event_binary_format Binary Format
The Post-Header has the following components:
<table>
<caption>Post-Header for Table_map_log_event</caption>
<tr>
<th>Name</th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
<td>table_id</td>
<td>6 bytes unsigned integer</td>
<td>The number that identifies the table.</td>
</tr>
<tr>
<td>flags</td>
<td>2 byte bitfield</td>
<td>Reserved for future use; currently always 0.</td>
</tr>
</table>
The Body has the following components:
<table>
<caption>Body for Table_map_log_event</caption>
<tr>
<th>Name</th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
<td>database_name</td>
<td>one byte string length, followed by null-terminated string</td>
<td>The name of the database in which the table resides. The name
is represented as a one byte unsigned integer representing the
number of bytes in the name, followed by length bytes containing
the database name, followed by a terminating 0 byte. (Note the
redundancy in the representation of the length.) </td>
</tr>
<tr>
<td>table_name</td>
<td>one byte string length, followed by null-terminated string</td>
<td>The name of the table, encoded the same way as the database
name above.</td>
</tr>
<tr>
<td>column_count</td>
<td>@ref packed_integer "Packed Integer"</td>
<td>The number of columns in the table, represented as a packed
variable-length integer.</td>
</tr>
<tr>
<td>column_type</td>
<td>List of column_count 1 byte enumeration values</td>
<td>The type of each column in the table, listed from left to
right. Each byte is mapped to a column type according to the
enumeration type enum_field_types defined in mysql_com.h. The
mapping of types to numbers is listed in the table @ref
Table_table_map_log_event_column_types "below" (along with
description of the associated metadata field). </td>
</tr>
<tr>
<td>metadata_length</td>
<td>@ref packed_integer "Packed Integer"</td>
<td>The length of the following metadata block</td>
</tr>
<tr>
<td>metadata</td>
<td>list of metadata for each column</td>
<td>For each column from left to right, a chunk of data who's
length and semantics depends on the type of the column. The
length and semantics for the metadata for each column are listed
in the table @ref Table_table_map_log_event_column_types
"below".</td>
</tr>
<tr>
<td>null_bits</td>
<td>column_count bits, rounded up to nearest byte</td>
<td>For each column, a bit indicating whether data in the column
can be NULL or not. The number of bytes needed for this is
int((column_count+7)/8). The flag for the first column from the
left is in the least-significant bit of the first byte, the second
is in the second least significant bit of the first byte, the
ninth is in the least significant bit of the second byte, and so
on. </td>
</tr>
</table>
The table below lists all column types, along with the numerical
identifier for it and the size and interpretation of meta-data used
to describe the type.
@anchor Table_table_map_log_event_column_types
<table>
<caption>Table_map_log_event column types: numerical identifier and
metadata</caption>
<tr>
<th>Name</th>
<th>Identifier</th>
<th>Size of metadata in bytes</th>
<th>Description of metadata</th>
</tr>
<tr>
<td>MYSQL_TYPE_DECIMAL</td><td>0</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td>MYSQL_TYPE_TINY</td><td>1</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td>MYSQL_TYPE_SHORT</td><td>2</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td>MYSQL_TYPE_LONG</td><td>3</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td>MYSQL_TYPE_FLOAT</td><td>4</td>
<td>1 byte</td>
<td>1 byte unsigned integer, representing the "pack_length", which
is equal to sizeof(float) on the server from which the event
originates.</td>
</tr>
<tr>
<td>MYSQL_TYPE_DOUBLE</td><td>5</td>
<td>1 byte</td>
<td>1 byte unsigned integer, representing the "pack_length", which
is equal to sizeof(double) on the server from which the event
originates.</td>
</tr>
<tr>
<td>MYSQL_TYPE_NULL</td><td>6</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td>MYSQL_TYPE_TIMESTAMP</td><td>7</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td>MYSQL_TYPE_LONGLONG</td><td>8</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td>MYSQL_TYPE_INT24</td><td>9</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td>MYSQL_TYPE_DATE</td><td>10</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td>MYSQL_TYPE_TIME</td><td>11</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td>MYSQL_TYPE_DATETIME</td><td>12</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td>MYSQL_TYPE_YEAR</td><td>13</td>
<td>0</td>
<td>No column metadata.</td>
</tr>
<tr>
<td><i>MYSQL_TYPE_NEWDATE</i></td><td><i>14</i></td>
<td>&ndash;</td>
<td><i>This enumeration value is only used internally and cannot
exist in a binlog.</i></td>
</tr>
<tr>
<td>MYSQL_TYPE_VARCHAR</td><td>15</td>
<td>2 bytes</td>
<td>2 byte unsigned integer representing the maximum length of
the string.</td>
</tr>
<tr>
<td>MYSQL_TYPE_BIT</td><td>16</td>
<td>2 bytes</td>
<td>A 1 byte unsigned int representing the length in bits of the
bitfield (0 to 64), followed by a 1 byte unsigned int
representing the number of bytes occupied by the bitfield. The
number of bytes is either int((length+7)/8) or int(length/8).</td>
</tr>
<tr>
<td>MYSQL_TYPE_NEWDECIMAL</td><td>246</td>
<td>2 bytes</td>
<td>A 1 byte unsigned int representing the precision, followed
by a 1 byte unsigned int representing the number of decimals.</td>
</tr>
<tr>
<td><i>MYSQL_TYPE_ENUM</i></td><td><i>247</i></td>
<td>&ndash;</td>
<td><i>This enumeration value is only used internally and cannot
exist in a binlog.</i></td>
</tr>
<tr>
<td><i>MYSQL_TYPE_SET</i></td><td><i>248</i></td>
<td>&ndash;</td>
<td><i>This enumeration value is only used internally and cannot
exist in a binlog.</i></td>
</tr>
<tr>
<td>MYSQL_TYPE_TINY_BLOB</td><td>249</td>
<td>&ndash;</td>
<td><i>This enumeration value is only used internally and cannot
exist in a binlog.</i></td>
</tr>
<tr>
<td><i>MYSQL_TYPE_MEDIUM_BLOB</i></td><td><i>250</i></td>
<td>&ndash;</td>
<td><i>This enumeration value is only used internally and cannot
exist in a binlog.</i></td>
</tr>
<tr>
<td><i>MYSQL_TYPE_LONG_BLOB</i></td><td><i>251</i></td>
<td>&ndash;</td>
<td><i>This enumeration value is only used internally and cannot
exist in a binlog.</i></td>
</tr>
<tr>
<td>MYSQL_TYPE_BLOB</td><td>252</td>
<td>1 byte</td>
<td>The pack length, i.e., the number of bytes needed to represent
the length of the blob: 1, 2, 3, or 4.</td>
</tr>
<tr>
<td>MYSQL_TYPE_VAR_STRING</td><td>253</td>
<td>2 bytes</td>
<td>This is used to store both strings and enumeration values.
The first byte is a enumeration value storing the <i>real
type</i>, which may be either MYSQL_TYPE_VAR_STRING or
MYSQL_TYPE_ENUM. The second byte is a 1 byte unsigned integer
representing the field size, i.e., the number of bytes needed to
store the length of the string.</td>
</tr>
<tr>
<td>MYSQL_TYPE_STRING</td><td>254</td>
<td>2 bytes</td>
<td>The first byte is always MYSQL_TYPE_VAR_STRING (i.e., 253).
The second byte is the field size, i.e., the number of bytes in
the representation of size of the string: 3 or 4.</td>
</tr>
<tr>
<td>MYSQL_TYPE_GEOMETRY</td><td>255</td>
<td>1 byte</td>
<td>The pack length, i.e., the number of bytes needed to represent
the length of the geometry: 1, 2, 3, or 4.</td>
</tr>
</table>
*/
class Table_map_log_event : public Log_event
{
......@@ -3410,7 +3777,7 @@ protected:
<caption>Incident event format</caption>
<tr>
<th>Symbol</th>
<th>Size<br/>(bytes)</th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
......
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