About FlushModeType



Flush mode setting.(Enum of JPA)


Performance in large transactions

Hello, we have a performance problem when we use a large transaction. Let's do exactly the same in several transactions the ObjectDB works much faster. In our use case, we create many new entities and between the creations we call a select query. The execution of the query becomes slower at each iteration. (In the query, we search for an item of type Entity2. However, there is only one entity.)   Pseudocode for the fast and the slow solution FAST: ... ; entityManager. setFlushMode ( FlushModeType . AUTO ) ; EntityTransaction ... ) ; entityManager. setFlushMode ( FlushModeType . AUTO ) ; EntityTransaction transaction ...


Setting and Tuning of JPA Queries

Explains various JPA query settings - result range, flush and lock.... Flush policy in JPA is represented by the FlushModeType javax.persistence.FlushModeType JPA enum Flush mode setting. See JavaDoc Reference ...


JPA Miscellaneous

Reference (JavaDoc) of JPA API, including PersistenceUtil, PersistenceUnitUtil, Cache, CacheRetrieveMode, CacheStoreMode, FlushModeType, LockModeType, PessimisticLockScope.... of various JPA operations: javax.persistence.FlushModeType javax.persistence.LockModeType ...



Returns an array containing the constants of this enum type.(Static Method of javax.persistence.FlushModeType)


Performance and memory usage of queries

Hello, we can't understand why the performance of queries is not the best and the execution requires so much memory. In the implementation of our UnitTests we have used "DELETE FROM Object" to delete the database. That did not work because we often get an "out of memory" exception. What's all done in the execution of queries? Why is so much memory is required, although from the application point of view, no object is loaded. ... ; import javax. persistence . FlushModeType ; import javax. persistence . OneToMany ; ... ( ) ; em. setFlushMode ( FlushModeType . AUTO ) ; em. getTransaction ( ...


Database(*.odb) file size on disk

Hello, we have questions about the file size of ObjectDB database on disk. Can you tell us something about how the deleting of entities affects the size of *.odb files on disk? -Will the released memory always used by new entities? -Will be the database file automatically reduced?   We have created a small test, in which we create and delete entities. It looks like that the released memory are reused but the the file not resized. The database is at the end empty again, but larger than the initial size. ... ; import javax. persistence . FlushModeType ; import javax. persistence . Id ; ... ( ) ; em. setFlushMode ( FlushModeType . AUTO ) ;   int objects = 1000 ...


Merge with Parent/Child entities not possible

Can you please tell me why the following unit test ends with "[ObjectDB 2.5.7_02] javax.persistence.RollbackException"? ... FetchType ; import javax. persistence . FlushModeType ; import javax. persistence . GeneratedValue ... ) ; entityManager. setFlushMode ( FlushModeType . AUTO ) ;   return entityManager ; ...


Entity has be persistended,but query not fetched?

I create a new entity T newT and persistend it,then I create a query "select t from T t" to fetch all T entities.But  then the newT is not contain in the query result. Why? ... code order: query. setFlushMode ( FlushModeType . AUTO ) ;   query. getResultList ( ... ) ; query. setFlushMode ( FlushModeType . AUTO ) ; System. out . println ...


remove() and persist() in same transaction => Attempt to reuse an existing primary key value

Hello Support, in our configuration (FlushModeType.AUTO) is the execution of  em.find(Entity.class, <id>) much faster than an equivalent query. To optimize the Performance we define a special Entity (A) with additional data that use an existing ID of another Entity (B) from another class (another table). On this point we get no conflicts. If we remove additional data for Entity (B) and then the special Entity (A) is empty, we remove the special Entity (A). ... Hello Support, in our configuration (FlushModeType.AUTO) is the execution of  em.find(Entity.class, <id>) ... ; import javax. persistence . FlushModeType ; import javax. persistence . Id ; ...