Hibernate what is flush

Flush operation order. Obtaining Hibernate 2. Architecture 2. Domain Model 3. Bootstrap 4. Schema generation 5. Persistence Context 6. Flushing 7. Database access 8. Transactions and concurrency control 9. JNDI Locking Fetching Batching Caching Interceptors and events Criteria Native SQL Queries Spatial Multitenancy OSGi One common case for explicitly flushing is when you create a new persistent entity and you want it to have an artificial primary key generated and assigned to it, so that you can use it later on in the same transaction.

In that case calling flush would result in your entity being given an id. Another case is if there are a lot of things in the 1st-level cache and you'd like to clear it out periodically in order to reduce the amount of memory used by the cache but you still want to commit the whole thing together. This is the case that Aleksei's answer covers. Both the EntityManager and the Hibernate Session define a flush method that, when called, triggers a manual flush.

This mode is useful when using multi-request logical transactions and only the last request should flush the persistence context. These actions are scheduled by the persist operation, either explicitly or through cascading the PersistEvent from a parent to a child entity. The dirty checking mechanism is responsible for determining if a managed entity has been modified since it was first loaded. Hibernate does not execute the SQL statements in the order of their associated entity state operations.

The order in which SQL statements are executed is given by the ActionQueue and not by the order in which entity state operations have been previously defined. Flushing Flushing is the process of synchronizing the state of the persistence context with the underlying database. AUTO flush on commit In the following example, an entity is persisted and then the transaction is committed.

Example 1. Automatic flushing on commit. Example 2. Example 3. Example 4. Example 5.