Replication of AUTO_INCREMENT
,
LAST_INSERT_ID()
, and
TIMESTAMP
values is done
correctly, subject to the following exceptions.
INSERT DELAYED ...
VALUES(LAST_INSERT_ID())
inserts a different value
on the master and the slave. (Bug#20819) This is fixed in
MySQL 5.1 when using row-based or mixed-format
binary logging. For more information, see
Replication Formats.
Before MySQL 5.0.26, a stored procedure that uses
LAST_INSERT_ID()
does not
replicate properly.
When a statement uses a stored function that inserts into an
AUTO_INCREMENT
column, the generated
AUTO_INCREMENT
value is not written into
the binary log, so a different value can in some cases be
inserted on the slave. This is also true of a trigger that
causes an INSERT
into an
AUTO_INCREMENT
column.
An insert into an AUTO_INCREMENT
column
caused by a stored routine or trigger running on a master
that uses MySQL 5.0.60 or earlier does not replicate
correctly to a slave running MySQL 5.1.12 through 5.1.23
(inclusive). (Bug#33029)
Adding an AUTO_INCREMENT
column to a
table with ALTER TABLE
might
not produce the same ordering of the rows on the slave and
the master. This occurs because the order in which the rows
are numbered depends on the specific storage engine used for
the table and the order in which the rows were inserted. If
it is important to have the same order on the master and
slave, the rows must be ordered before assigning an
AUTO_INCREMENT
number. Assuming that you
want to add an AUTO_INCREMENT
column to a
table t1
that has columns
col1
and col2
, the
following statements produce a new table
t2
identical to t1
but
with an AUTO_INCREMENT
column:
CREATE TABLE t2 LIKE t1; ALTER TABLE t2 ADD id INT AUTO_INCREMENT PRIMARY KEY; INSERT INTO t2 SELECT * FROM t1 ORDER BY col1, col2;
To guarantee the same ordering on both master and slave,
the ORDER BY
clause must name
all columns of t1
.
The instructions just given are subject to the limitations
of CREATE TABLE ... LIKE
: Foreign key
definitions are ignored, as are the DATA
DIRECTORY
and INDEX DIRECTORY
table options. If a table definition includes any of those
characteristics, create t2
using a
CREATE TABLE
statement that
is identical to the one used to create
t1
, but with the addition of the
AUTO_INCREMENT
column.
Regardless of the method used to create and populate the
copy having the AUTO_INCREMENT
column,
the final step is to drop the original table and then rename
the copy:
DROP t1; ALTER TABLE t2 RENAME t1;
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