7.4.4.3 Mixed Binary Logging Format

When running in MIXED logging format, the server automatically switches from statement-based to row-based logging under the following conditions:

• When a function contains UUID().

• When one or more tables with AUTO_INCREMENT columns are updated and a trigger or stored function is invoked. Like all other unsafe statements, this generates a warning if binlog_format = STATEMENT.

  For more information, see Section 19.5.1.1, “Replication and AUTO_INCREMENT”.

• 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 loadable function is involved.

• When FOUND_ROWS() or ROW_COUNT() is used. (Bug #12092, Bug #30244)

• When USER(), CURRENT_USER(), or CURRENT_USER is used. (Bug #28086)

• When one of the tables involved is a log table in the mysql database.

• When the LOAD_FILE() function is used. (Bug #39701)

• 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:

  • auto_increment_increment

  • auto_increment_offset

  • character_set_client

  • character_set_connection

  • character_set_database

  • character_set_server

  • collation_connection

  • collation_database

  • collation_server

  • foreign_key_checks

  • identity

  • last_insert_id

  • lc_time_names

  • pseudo_thread_id

  • sql_auto_is_null

  • time_zone

  • timestamp

  • unique_checks

  For information about determining system variable scope, see Section 7.1.9, “Using System Variables”.

  For information about how replication treats sql_mode, see Section 19.5.1.39, “Replication and Variables”.

In releases prior to MySQL 8.0, when mixed binary logging format was in use, if a statement was logged by row and the session that executed the statement had any temporary tables, all subsequent statements were treated as unsafe and logged in row-based format until all temporary tables in use by that session were dropped. In MySQL 8.4, operations on temporary tables are not logged in mixed binary logging format, and the presence of temporary tables in the session has no impact on the logging mode used for each statement.

Note

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
NDB	Yes	No

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 capabilities of the storage engine (statement capable, row capable, both, or neither). (Binary injection refers to logging a change that must be logged using ROW format.)

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. Type, binlog_format, SLC, and RLC columns outline the conditions, and Error / Warning and Logged as columns represent the corresponding actions. SLC stands for “statement-logging capable”, and RLC stands for “row-logging capable”.

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	-	STATEMENT
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

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 replica has log_error_verbosity set to display warnings, the replica 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, statements that are unsafe for statement-based logging, and so forth.