If a master server does not write a statement to its binary log, the statement is not replicated. If the server does log the statement, the statement is sent to all slaves and each slave determines whether to execute it or ignore it.
On the master, you can control which databases to log changes for
by using the --binlog-do-db and
--binlog-ignore-db options to
control binary logging. For a description of the rules that
servers use in evaluating these options, see
Section 17.2.3.1, “Evaluation of Database-Level Replication and Binary Logging Options”. You should not use
these options to control which databases and tables are
replicated. Instead, use filtering on the slave to control the
events that are executed on the slave.
On the slave side, decisions about whether to execute or ignore
statements received from the master are made according to the
--replicate-* options that the slave was started
with. (See Section 17.1.3, “Replication and Binary Logging Options and Variables”.)
In the simplest case, when there are no
--replicate-* options, the slave executes all
statements that it receives from the master. Otherwise, the result
depends on the particular options given.
Database-level options
(--replicate-do-db,
--replicate-ignore-db) are checked
first; see Section 17.2.3.1, “Evaluation of Database-Level Replication and Binary Logging Options”, for a
description of this process. If no matching database-level options
are found, option checking proceeds to any table-level options
that may be in use, as discussed in
Section 17.2.3.2, “Evaluation of Table-Level Replication Options”.
To make it easier to determine what effect an option set will
have, it is recommended that you avoid mixing “do”
and “ignore” options, or wildcard and nonwildcard
options. An example of the latter that may have unintended effects
is the use of --replicate-do-db and
--replicate-wild-do-table together,
where --replicate-wild-do-table
uses a pattern for the database name that matches the name given
for --replicate-do-db. Suppose a
replication slave is started with
--replicate-do-db=dbx
--replicate-wild-do-table=db%.t1.
Then, suppose that on the master, you issue the statement
CREATE DATABASE
dbx. Although you might expect it, this statement is not
replicated because it does not reference a table named
t1.
If any --replicate-rewrite-db
options were specified, they are applied before the
--replicate-* filtering rules are tested.
In MySQL 5.5, database-level filtering options are
case-sensitive on platforms supporting case sensitivity in
filenames, whereas table-level filtering options are not
(regardless of platform). This is true regardless of the value
of the lower_case_table_names
system variable.