Motivation:
This article is useful if you want to vary the batching size per Hibernate Session. While global (application-level) batching size can be easily set via the hibernate.jdbc.batch_size property in application.properties, starting with Hibernate 5.2, we can programatically set a different value for batch size for each batch.
Description:
This application is an example of batch inserts via Hibernate session-level batching (Hibernate 5.2 or higher) against MySQL (of course, you can use any other database). The implementation from this example commits the database transaction after each batch execution. This way, we avoid long-running transactions and, in case of a failure, we rollback only the failed batch and don't lose the previous batches. Moreover, for each batch, the Persistence Context is flushed and cleared, therefore we maintain a thin Persistence Context. Keeping a small Persistence Context is one of the top practice to maintain a high-performance persistence layer. This way, the code is not prone to memory errors and performance penalties caused by slow flushes.
Key points:
The batch size is set programatically via Session#setJdbcBatchSize(Integer size) and get or obtained via Session#getJdbcBatchSize() as below:
Tam Ta Da Dam! :) The complete code is available on GitHub.
If you need a deep dive into the performance recipes exposed in this repository then I am sure that you will love my book "Spring Boot Persistence Best Practices".
