Felix König ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=5a4bad5... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiNzQ4MDAzYTFl... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16249?atlOrigin=eyJpIjoiNzQ4MD... ) HHH-16249 ( https://hibernate.atlassian.net/browse/HHH-16249?atlOrigin=eyJpIjoiNzQ4MD... ) StatelessSession does not flush when using jdbc batch_size > 1 ( https://hibernate.atlassian.net/browse/HHH-16249?atlOrigin=eyJpIjoiNzQ4MD... ) Issue Type: Bug Affects Versions: 6.1.7 Assignee: Unassigned Attachments: hibernate-stateless-session-flush-bug-repro-HHH-4042.zip Components: hibernate-core Created: 03/Mar/2023 04:34 AM Priority: Major Reporter: Felix König ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=5a4bad5... ) This is a duplicate of https://hibernate.atlassian.net/browse/HHH-4042 ( https://hibernate.atlassian.net/browse/HHH-4042 ) , but that one was closed and I was asked to create a new issue, so here it is 🙂 I have attached a reproducer. Here’s also a minimal snippet to reproduce the issue: session.doWork(connection -> { try (StatelessSession statelessSession = session.getSessionFactory().openStatelessSession(connection)) { statelessSession.setJdbcBatchSize(2); statelessSession.insert( new TestEntity(1)); statelessSession.insert( new TestEntity(2)); statelessSession.insert( new TestEntity(3)); } }); session.flush(); List<TestEntity> entities = session.createQuery( "select t from TestEntity t" , TestEntity.class).getResultList(); Assert.assertEquals( "All 3 entities were persisted" , 3, entities.size()); ( https://hibernate.atlassian.net/browse/HHH-16249#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16249#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100217- sha1:65be9f2 )