MySQL 5.5 Release Notes
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Replication works because events written to the binary log are read from the master and then processed on the slave. The events are recorded within the binary log in different formats according to the type of event. The different replication formats used correspond to the binary logging format used when the events were recorded in the master's binary log. The correlation between binary logging formats and the terms used during replication are:
Replication capabilities in MySQL originally were based on propagation of SQL statements from master to slave. This is called statement-based replication (often abbreviated as SBR), which corresponds to the standard statement-based binary logging format. In older versions of MySQL (5.1.4 and earlier), binary logging and replication used this format exclusively.
Row-based binary logging logs changes in individual table rows. When used with MySQL replication, this is known as row-based replication (often abbreviated as RBR). In row-based replication, the master writes events to the binary log that indicate how individual table rows are changed.
The server can change the binary logging format in real time according to the type of event using mixed-format logging.
When the mixed format is in effect, statement-based logging is used by default, but automatically switches to row-based logging in particular cases as described later. Replication using the mixed format is often referred to as mixed-based replication or mixed-format replication. For more information, see Section 5.4.4.3, “Mixed Binary Logging Format”.
In MySQL 5.5, statement-based format is the default.
NDB Cluster.
The default binary logging format in all MySQL NDB Cluster 7.2
releases, beginning with MySQL NDB Cluster 7.2.1, is
STATEMENT. (This is a change from previous
versions of NDB Cluster.) You should note that NDB Cluster
Replication always uses row-based replication, and that the
NDB storage engine is incompatible
with statement-based replication. This means that you must
manually set the format to ROW prior to
enabling NDB Cluster Replication. See
Section 18.6.2, “General Requirements for NDB Cluster Replication”, for more
information.
When using MIXED format, the binary logging
format is determined in part by the storage engine being used and
the statement being executed. For more information on mixed-format
logging and the rules governing the support of different logging
formats, see Section 5.4.4.3, “Mixed Binary Logging Format”.
The logging format in a running MySQL server is controlled by
setting the binlog_format server
system variable. This variable can be set with session or global
scope. The rules governing when and how the new setting takes
effect are the same as for other MySQL server system variables.
Setting the variable for the current session lasts only until the
end of that session, and the change is not visible to other
sessions. Setting the variable globally takes effect for clients
that connect after the change, but not for any current client
sessions, including the session where the variable setting was
changed. To make the global system variable setting permanent so
that it applies across server restarts, you must set it in an
option file. For more information, see
Section 13.7.4.1, “SET Syntax for Variable Assignment”.
There are conditions under which you cannot change the binary logging format at runtime or doing so causes replication to fail. See Section 5.4.4.2, “Setting The Binary Log Format”.
Changing the global binlog_format
value requires privileges sufficient to set global system
variables. Changing the session
binlog_format value requires
privileges sufficient to set restricted session system variables.
See Section 5.1.8.1, “System Variable Privileges”.
The statement-based and row-based replication formats have different issues and limitations. For a comparison of their relative advantages and disadvantages, see Section 17.1.2.1, “Advantages and Disadvantages of Statement-Based and Row-Based Replication”.
With statement-based replication, you may encounter issues with replicating stored routines or triggers. You can avoid these issues by using row-based replication instead. For more information, see Section 20.7, “Binary Logging of Stored Programs”.