How Hibernate Batch insert works?

Question

Can some one explain me how

hibernate.jdbc.batch_size=1000 

and

if (i % 100 == 0 && i>0) {
                           


        

Answer 1

Batch Processing allows you to group related SQL statements into a batch and submit them with one call to the database.

Why we need

It is important to keep in mind, that each update added to a Statement or PreparedStatement is executed separately by the database. That means, that some of them may succeed before one of them fails. All the statements that have succeeded are now applied to the database, but the rest of the updates may not be. This can result in an inconsistent data in the database.

To avoid this, you can execute the batch update inside a transaction. When executed inside a transaction you can make sure that either all updates are executed, or none are. Any successful updates can be rolled back, in case one of the updates fail.

What is Batch and Flushing

Batch size and flushing is different thing. when you set hibernate.jdbc.batch_size to 1000 it means hibernate will do batch inserts or update upto 1000 entities.flush operation can be used the write all changes to the database before the transaction is committed

if your batch size is set to 1000, and you flush every 100 entity, Hibernate will execute lots of small batches of 100 insert or update statements for 10 times.

Please read more below this link:

http://docs.jboss.org/hibernate/orm/3.3/reference/en/html/batch.html

Why number of objects being flushed should be equal to hibernate.jdbc.batch_size?