When running in MIXED logging format,
automatic switching from statement-based to row-based logging
takes place under the following conditions:
When a function contains
UUID().When one or more tables with
AUTO_INCREMENTcolumns are updated and a trigger or stored function is invoked. Like all other unsafe statements, this generates a warning ifbinlog_format = STATEMENT.For more information, see Section 17.4.1.1, “Replication and
AUTO_INCREMENT”.When any
INSERT DELAYEDis 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 session 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 session are dropped.
This is true whether or not any temporary tables are actually logged.
Temporary tables cannot be logged using row-based format; thus, once row-based logging is used, all subsequent statements using that table are unsafe. The server approximates this condition by treating all statements executed during the session as unsafe until the session no longer holds any temporary tables.
When
FOUND_ROWS()orROW_COUNT()is used. (Bug#12092, Bug#30244)When
USER(),CURRENT_USER(), orCURRENT_USERis used. (Bug#28086)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 5.1.5, “Using System Variables”.
For information about how replication treats
sql_mode, see Section 17.4.1.32, “Replication and Variables”.When one of the tables involved is a log table in the
mysqldatabase.When the
LOAD_FILE()function is used. (Bug#39701)
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 error log to prevent flooding the
log.
In addition to the decisions above, individual engines can also determine the logging format used when information in a table is updated. The logging capabilities of an individual engine can be 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.
A given storage engine can support either or both logging formats. The following table lists the formats supported by each 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 |
In MySQL 5.5.3 and later, whether a statement is to be logged
and the logging mode to be used is determined according to the
type of statement (safe, unsafe, or binary injected), the binary
logging format (STATEMENT,
ROW, or MIXED), and the
logging capabailities of the storage engine (statement capable,
row capable, both, or neither). Statements may be logged with or
without a warning; failed statements are not logged, but
generate errors in the log. This is shown in the following
decision table.
| Condition | Action | ||||
|---|---|---|---|---|---|
| Type | binlog_format | SLC | RLC | Error / Warning | Logged as |
| * | * | No | No | Error: Cannot execute statement: Binary logging is impossible since at least one engine is involved that is both row-incapable and statement-incapable. | - |
| Safe | STATEMENT | Yes | No | - | STATEMENT |
| Safe | MIXED | Yes | No | - | STATEMENT |
| Safe | ROW | Yes | No | Error: Cannot execute statement: Binary logging
is impossible since BINLOG_FORMAT =
ROW and at least one table uses a storage
engine that is not capable of row-based logging. | - |
| Unsafe | STATEMENT | Yes | No | Warning: Unsafe statement binlogged in statement
format, since BINLOG_FORMAT =
STATEMENT | STATEMENT |
| Unsafe | MIXED | Yes | No | Error: Cannot execute statement: Binary logging
of an unsafe statement is impossible when the storage
engine is limited to statement-based logging, even if
BINLOG_FORMAT = MIXED. | - |
| Unsafe | ROW | Yes | No | Error: Cannot execute statement: Binary logging
is impossible since BINLOG_FORMAT =
ROW and at least one table uses a storage
engine that is not capable of row-based logging. | - |
| Row Injection | STATEMENT | Yes | No | Error: Cannot execute row injection: Binary logging is not possible since at least one table uses a storage engine that is not capable of row-based logging. | - |
| Row Injection | MIXED | Yes | No | Error: Cannot execute row injection: Binary logging is not possible since at least one table uses a storage engine that is not capable of row-based logging. | - |
| Row Injection | ROW | Yes | No | Error: Cannot execute row injection: Binary logging is not possible since at least one table uses a storage engine that is not capable of row-based logging. | - |
| Safe | STATEMENT | No | Yes | Error: Cannot execute statement: Binary logging
is impossible since BINLOG_FORMAT =
STATEMENT and at least one table uses a
storage engine that is not capable of statement-based
logging. | - |
| Safe | MIXED | No | Yes | - | ROW |
| Safe | ROW | No | Yes | - | ROW |
| Unsafe | STATEMENT | No | Yes | Error: Cannot execute statement: Binary logging
is impossible since BINLOG_FORMAT =
STATEMENT and at least one table uses a
storage engine that is not capable of statement-based
logging. | - |
| Unsafe | MIXED | No | Yes | - | ROW |
| Unsafe | ROW | No | Yes | - | ROW |
| Row Injection | STATEMENT | No | Yes | Error: Cannot execute row injection: Binary
logging is not possible since BINLOG_FORMAT =
STATEMENT. | - |
| Row Injection | MIXED | No | Yes | - | ROW |
| Row Injection | ROW | No | Yes | - | ROW |
| Safe | STATEMENT | Yes | Yes | - | STATEMENT |
| Safe | MIXED | Yes | Yes | - | ROW |
| Safe | ROW | Yes | Yes | - | ROW |
| Unsafe | STATEMENT | Yes | Yes | Warning: Unsafe statement binlogged in statement
format since BINLOG_FORMAT =
STATEMENT. | STATEMENT |
| Unsafe | MIXED | Yes | Yes | - | ROW |
| Unsafe | ROW | Yes | Yes | - | ROW |
| Row Injection | STATEMENT | Yes | Yes | Error: Cannot execute row injection: Binary
logging is not possible because BINLOG_FORMAT =
STATEMENT. | - |
| Row Injection | MIXED | Yes | Yes | - | ROW |
| Row Injection | ROW | Yes | Yes | - | ROW |
The decision-making process for binary logging changed in MySQL 5.5.3, due to the fix for Bug#39934. Prior to MySQL 5.5.3, when determining the logging mode to be used, the capabilities of all the tables affected by the event are combined, and 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, 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 row-logging capable. Similarly, a statement is row-logging restricted if any table accessed by the statement is not statement-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 to prevent flooding the log. The log message includes 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.