About persistence

forum_thread

Entity Management Config questions

Hi, the manual states the following regarding config of Entities: http://www.objectdb.com/java/jpa/setting/entities  : <cache ref="weak" level2="0mb" /> The <cache> element specifies settings of the two cache mechanisms for entities:... reference type for holding non dirty entities in the persistence context of the EntityManager javax.persistence.EntityManager JPA interface Interface used to interact with the persistence context. See JavaDoc Reference Page... (which serves ...

 
forum_thread

How to use JOIN FETCH?

The ObjectDB manual (http://www.objectdb.com/java/jpa/query/jpql/from) gives an example of using JOIN FETCH to avoid excessive round trips to the database: ... java. util . Map ;   import javax. persistence . Entity ; import javax. persistence . EntityManager ; import javax. persistence . ...

 
api-jpa

getPersistenceType()

Return the persistence type.(Method of javax.persistence.metamodel.Type)

 
forum_thread

Left join fetch behaviour doesn't retrieve children?

Hello support, I'm a little bit confused about a left join fetch behaviour. In this test case, i try to fetch my 3 children using a left join fetch. But my collection is null after closing the em. It was expected to be fetched before closing the em, no ? In fact, that is the objective of the fetch purpose (i guess ?). ... java. util . Set ;   import javax. persistence . CascadeType ; import javax. persistence . Entity ; import javax. persistence . ...

 
forum_thread

EntityManager JPA or JDO impl and different behavior

Hi, I have an issue with the EntityManager. My persistance XML looks like: <?xml version="1.0" encoding="UTF-8"?> <persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"> ... = "1.0" encoding = "UTF-8" ?> <persistence version = "2.0" xmlns = "http://java.sun.com/xml/ns/persistence" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation = "http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" > ...

 
forum_thread

Run out of memory

Hi, I've been looking into ObjectDB for our use, where everything has been great apart from I'm stuck on the following problem.   I am trying to load a large file (> 1GB), process certain information and store it back in the database to access / modify later. I require to be able to rollback changes as well, where there can be massive amount of changes.   ... the batch shown at http://www.objectdb.com/java/jpa/persistence/store#Batch_Store_ . However the problem is that it seems that ...

 
api-jpa

javax.persistence.Embedded

Specifies a persistent field or property of an entity whose value is an instance of an embeddable class.(Annotation of JPA)

 
api-jdo

javax.jdo.spi.StateManager

This interface is the point of contact between managed instances of PersistenceCapable classes and the JDO implementation.(Interface of JDO)

 
api-jpa

javax.persistence.PersistenceUnitUtil

Utility interface between the application and the persistence provider managing the persistence unit.(Interface of JPA)

 
api-jdo

javax.jdo.spi.StateInterrogation

This interface is implemented by a non-binary-compatible JDO implementation to provide state interrogation for non-enhanced persistent classes.(Interface of JDO)