Spring Hibernate, avoid statements registering and closing repeatively

Question

I am in the process of optimizing an algorithm, and I noticed that Hibernate creates and releases update statements repetitively instead of reusing them. These are all from the same query.

15:57:31,589 TRACE [.JdbcCoordinatorImpl]:371 - Registering statement [sql : 'update ...
15:57:31,591 TRACE [.JdbcCoordinatorImpl]:412 - Releasing statement [sql : 'update ...
15:57:31,592 TRACE [.JdbcCoordinatorImpl]:525 - Closing prepared statement [sql : 'update ...
15:57:31,592 TRACE [.JdbcCoordinatorImpl]:278 - Starting after statement execution processing [ON_CLOSE]
15:57:31,594 TRACE [.JdbcCoordinatorImpl]:371 - Registering statement [sql : 'update ...
15:57:31,595 TRACE [.JdbcCoordinatorImpl]:412 - Releasing statement [sql : 'update ...
15:57:31,596 TRACE [.JdbcCoordinatorImpl]:525 - Closing prepared statement [sql : 'update ...
15:57:31,596 TRACE [.JdbcCoordinatorImpl]:278 - Starting after statement execution processing [ON_CLOSE]
15:57:31,597 TRACE [.JdbcCoordinatorImpl]:371 - Registering statement [sql : 'update ...
15:57:31,599 TRACE [.JdbcCoordinatorImpl]:412 - Releasing statement [sql : 'update ...
15:57:31,600 TRACE [.JdbcCoordinatorImpl]:525 - Closing prepared statement [sql : 'update ...
15:57:31,601 TRACE [.JdbcCoordinatorImpl]:278 - Starting after statement execution processing [ON_CLOSE]

The algorithm's main method has a @Scope and a @Transactional annotation. The expected behavior is that, if anything goes wrong, the algorithm's updates are ROLLBACK.

Beneath, the algorithm uses a @Service which has a different @Scope and is also @Transactional. The service is the one using Hibernate to update the database, with session.update(entity). The documentation says that, by default, nested transactions reuse the transaction if it exists.

• Is that affirmation above correct?
• Can the scope change create problems?
• How can I have Hibernate reuse the statement during the transaction?

Thanks for your attention

Answer 1

Your understanding is correct. The scope is not related to how transactions are propagated, Spring should wrap your beans with proxies that control transactions regardless of scope.

There is no way to reuse statements when using Hibernate. Even when writing JDBC code manually it is not recommended approach, due to entanglement of code that such approach forces. Common answer to this is to use prepared statement cache on JDBC connection pool. For example with Apache DBCP pool you can use poolPreparedStatements and maxOpenPreparedStatements to control that. Pools bundled with application servers have similar settings.