No matter what, I can't batch MySQL INSERT statements in Hibernate

Solution 1:

It's likely your queries are being rewritten but you wouldn't know if by looking at the Hibernate SQL logs. Hibernate does not rewrite the insert statements - the MySQL driver rewrites them. In other words, Hibernate will send multiple insert statements to the driver, and then the driver will rewrite them. So the Hibernate logs only show you what SQL Hibernate sent to the driver, not what SQL the driver sent to the database.

You can verify this by enabling MySQL's profileSQL parameter in connection url:

<b:property name="jdbcUrl" value="jdbc:mysql://server:3306/db?autoReconnect=true&amp;rewriteBatchedStatements=true&amp;profileSQL=true" />

Using an example similar to yours, this is what my output looks like:

insert into Person (firstName, lastName, id) values (?, ?, ?)
insert into Person (firstName, lastName, id) values (?, ?, ?)
insert into Person (firstName, lastName, id) values (?, ?, ?)
insert into Person (firstName, lastName, id) values (?, ?, ?)
insert into Person (firstName, lastName, id) values (?, ?, ?)
insert into Person (firstName, lastName, id) values (?, ?, ?)
insert into Person (firstName, lastName, id) values (?, ?, ?)
insert into Person (firstName, lastName, id) values (?, ?, ?)
insert into Person (firstName, lastName, id) values (?, ?, ?)
insert into Person (firstName, lastName, id) values (?, ?, ?)
Wed Feb 05 13:29:52 MST 2014 INFO: Profiler Event: [QUERY]  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) duration: 1 ms, connection-id: 81, statement-id: 33, resultset-id: 0, message: insert into Person (firstName, lastName, id) values ('person1', 'Name', 1),('person2', 'Name', 2),('person3', 'Name', 3),('person4', 'Name', 4),('person5', 'Name', 5),('person6', 'Name', 6),('person7', 'Name', 7),('person8', 'Name', 8),('person9', 'Name', 9),('person10', 'Name', 10)

The first 10 lines are being logged by Hibernate though this not what is actually being sent to MySQL database. The last line is coming from MySQL driver and it clearly shows a single batch insert with multiple values and that is what is actually being sent to the MySQL database.