When running in MIXED
mode, automatic
switching from statement-based to row-based replication takes
place under the following conditions:
When a DML statement updates an
NDBCLUSTER
table.
When a function contains
UUID()
.
Prior to MySQL 5.1.40, when two or more tables with
AUTO_INCREMENT
columns are updated. As of
5.1.40, when one or more tables with
AUTO_INCREMENT
columns are updated and a
trigger or stored function is invoked. Unlike other unsafe
statements, this does not generate a warning if
binlog_format = STATEMENT
.
When any INSERT DELAYED
is
executed.
When the body of a view requires row-based replication, the
statement creating the view also uses it — for
example, this occurs when the statement creating a view uses
the UUID()
function.
When a call to a UDF is involved.
If a statement is logged by row and the client that executed the statement has any temporary tables, logging by row is used for all subsequent statements (except for those accessing temporary tables) until all temporary tables in use by that client are dropped.
This is true whether or not any temporary tables are actually logged.
Temporary tables cannot be logged using the row-based format; thus, once row-based logging is used, all subsequent statements using that table are unsafe, and we approximate this condition by treating all statements made by that client as unsafe until the client no longer holds any temporary tables.
Beginning with MySQL 5.1.23:
When FOUND_ROWS()
or
ROW_COUNT()
is used.
(Bug#12092, Bug#30244)
When USER()
,
CURRENT_USER()
, or
CURRENT_USER
is used.
(Bug#28086)
Beginning with MySQL 5.1.24, when a statement refers to one or more system variables. (Bug#31168)
Exception. The following system variables, when used with session scope (only), do not cause the logging format to switch:
For information about determining system variable scope, see Section 5.1.6, “Using System Variables”.
For information about how replication treats
sql_mode
, see
Section 16.4.1.31, “Replication and Variables”.
Beginning with MySQL 5.1.30, when one of the tables involved
is a log table in the mysql
database.
Beginning with MySQL 5.1.34, when the
LOAD_FILE()
function is used.
(Bug#39701)
Starting with MySQL 5.1.20, a warning is generated if you try
to execute a statement using statement-based logging that
should be written using row-based logging. The warning is
shown both in the client (in the output of
SHOW WARNINGS
) and through the
mysqld error log. A warning is added to the
SHOW WARNINGS
table each time
such a statement is executed. However, only the first
statement that generated the warning for each client session
is written to the mysqld
error log to
prevent flooding the log.
Starting with MySQL 5.1.20, in addition to the decisions above, individual engines can also determine the logging format used when information in a table is updated. The following table lists the logging formats supported by each storage engine.
Storage Engine | Row Logging Supported | Statement Logging Supported |
---|---|---|
ARCHIVE |
Yes | Yes |
BLACKHOLE |
Yes | Yes |
CSV |
Yes | Yes |
EXAMPLE |
Yes | No |
FEDERATED |
Yes | Yes |
HEAP |
Yes | Yes |
InnoDB |
Yes | Yes when the transaction isolation level is
REPEATABLE READ or
SERIALIZABLE ; No
otherwise. |
MyISAM |
Yes | Yes |
MERGE |
Yes | Yes |
NDBCLUSTER |
Yes | No |
A given storage engine can support either or both logging formats; the logging capabilities of an individual engine can be further defined as follows:
If an engine supports row-based logging, the engine is said to be row-logging capable.
If an engine supports statement-based logging, the engine is said to be statement-logging capable.
When determining the logging mode to be used, the capabilities of all the tables affected by the event are combined. The set of affected tables is then marked according to these rules:
A set of tables is defined as row logging restricted if the tables are row logging capable but not statement logging capable.
A set of tables is defined as statement logging restricted if the tables are statement logging capable but not row logging capable.
Once the determination of the possible logging formats required
by the statement is complete it is compared to the current
binlog_format
setting. The
following table is used to decide how the information is
recorded in the binary log or, if appropriate, whether an error
is raised. In the table, a safe operation is defined as one that
is deterministic.
Several rules decide whether the statement is deterministic or not, as shown in the following table, where SLR stands for “statement-logging restricted” and RLR stands for “row-logging restricted”. A statement is statement-logging restricted if one or more of the tables it accesses is not statement-logging capable. Similarly, a statement is row-logging restricted if any table accessed by the statement is not row-logging capable.
Condition | Action | ||||
---|---|---|---|---|---|
Safe/unsafe | binlog_format |
SLR | RLR | Error/Warning | Logged as |
Safe | STATEMENT |
Yes | Yes | Error: not loggable | |
Safe | STATEMENT |
Yes | No | STATEMENT |
|
Safe | STATEMENT |
No | Yes | Error: not loggable | |
Safe | STATEMENT |
No | No | STATEMENT |
|
Safe | MIXED |
Yes | Yes | Error: not loggable | |
Safe | MIXED |
Yes | No | STATEMENT |
|
Safe | MIXED |
No | Yes | ROW |
|
Safe | MIXED |
No | No | STATEMENT |
|
Safe | ROW |
Yes | Yes | Error: not loggable | |
Safe | ROW |
Yes | No | Error: not loggable | |
Safe | ROW |
No | Yes | ROW |
|
Safe | ROW |
No | No | ROW |
|
Unsafe | STATEMENT |
Yes | Yes | Error: not loggable | |
Unsafe | STATEMENT |
Yes | No | Warning: unsafe | STATEMENT |
Unsafe | STATEMENT |
No | Yes | Error: not loggable | |
Unsafe | STATEMENT |
No | No | Warning: unsafe | STATEMENT |
Unsafe | MIXED |
Yes | Yes | Error: not loggable | |
Unsafe | MIXED |
Yes | No | Error: not loggable | |
Unsafe | MIXED |
No | Yes | ROW |
|
Unsafe | MIXED |
No | No | ROW |
|
Unsafe | ROW |
Yes | Yes | Error: not loggable | |
Unsafe | ROW |
Yes | No | Error: not loggable | |
Unsafe | ROW |
No | Yes | ROW |
|
Unsafe | ROW |
No | No | ROW |
When a warning is produced by the determination, a standard
MySQL warning is produced (and is available using
SHOW WARNINGS
). The information
is also written to the mysqld error log. Only
one error for each error instance per client connection is
logged. The log message will include the SQL statement that was
attempted.
If a slave server was started with
--log-warnings
enabled, the slave
prints messages to the error log to provide information about
its status, such as the binary log and relay log coordinates
where it starts its job, when it is switching to another relay
log, when it reconnects after a disconnect, and so forth.
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