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forum_thread

Several parallel threads to speed up query on one DB

Hi, I have an application: producer (from a DB) to a consumer. The current bottleneck is the producer from DB (based on a query) and I would like to speed it up. I have tried using several entity managers (same DB instance) to benefit from the parallelisation - but it looks like I don't get much benefit from doing that.  ... each query - The lock contention disappears when I removed the "em.clear()" - Obviously I need to clear the entity managers - it ...

 
forum_thread

Problem persisting a TreeSet field

Hello, I am getting a "java.lang.IllegalArgumentException: Can not set java.util.TreeSet field Message.children to java.util.HashSet" when persisting a Message object with a parent/children relationship: @ManyToOne private Message parent; @OneToMany(mappedBy = "parent") private TreeSet<Message> children; Seems that objectdb is converting TreeSet into HashSet? Why? http://www.objectdb.com/java/jpa/entity/types says TreeSet is supported... #1 2011-07-17 16:09 Hello, I am getting a "java.lang.IllegalArgumentException: Can not set java.util.TreeSet field Message.ch ...

 
forum_thread

Performance question

Hello, suppose you have an entity that holds a reference to another entity which in turn contains e.g. a date field you want to query for. Is there an improvement in performance if I create a "mirror" date field in the original entity, removing the need to traverse through the referenced other entity? So, querying for "all objects with object.otherobject.date > 1.1.1980" is slower than "all objects with object.date > 1.1.1980"? Or doesn't this matter, using proper indexing? Thanks, Benjamin #1 2011-10-20 19:01 Hello, suppose you have an entity that holds a reference to another entity which in turn contains e.g. a ...

 
forum_thread

Usage of Inherited Class

Hi, I found a problem in ObjectDB which may be incompatible with EclipseLink and JPA. Here's the codes: // Nodes.java #1 2011-05-22 16:00 Hi, I found a problem in ObjectDB which may be incompatible with EclipseLink and JPA. The type nodes2 der ...

 
forum_thread

Problem to use find method on an abstract Class: AbstractMethodError is thrown

Hi, I'm using JBoss AS 7 WildFly with ObjectDB installed as a module ( also Java 7, Eclipse Juno) In my db there are objects of type SentenceStatement which inherit from type LogicalObject  When I use find method mentioning SentenceStatement everything works just fine but when I use this method mentioning LogicalObject I get AbstractMethodError Please see services.Tester class with the 2 options for a better ease    this is the stack trace when I try to find LogicalObject: #1 2013-10-26 00:17 Hi, I'm using JBoss AS 7 WildFly with ObjectDB installed as a module ( also Java 7, Eclipse Juno) ...

 
forum_thread

Missing atificat for ObjectDB?

Hello! I am testing the Spring MVC and JPA tutorial, and always got an error in the POM file: <dependency>             <groupId>com.objectdb</groupId>             <artifactId>objectdb</artifactId>             <version>2.0.4</version>         </dependency>   #1 2013-11-11 22:49 Hello! I am testing the Spring MVC and JPA tutorial, and always got an error in the POM file: <depend ...

 
api-jpa

groupBy(grouping)

Specify the expressions that are used to form groups over the subquery results.(Method of javax.persistence.criteria.Subquery)

 
forum_thread

Exception while accessing the Persistence unit ...?

Hi, I am new to ObjectDB I was trying your eclipse/jee6/glassfish tutorial. I am getting the following exception: #1 2012-04-09 04:39 Hi, I am new to ObjectDB I was trying your eclipse/jee6/glassfish tutorial. I am getting the following ex ...

 
forum_thread

Heap Limit reached although the option 'objectdb.temp.page-file' is activated

We persisted many entities in a transaction, unfortunately the heap reached its limit at any time although the flush and the GC were invoked regularly. The attachments show the memory heap dump of the biggest consumer. Which objects you would actually expect to remove by the garbage collector? Why the option objectdb.temp.page-file does not perform?   Options: <temp path="$temp" threshold="512mb" /> #1 2016-02-18 07:48 We persisted many entities in a transaction, unfortunately the heap reached its limit at any time although the fl ...

 
forum_thread

Uninitialized primary key (id = 0)

Exception in thread "main" [ObjectDB 2.2.9_04] javax.persistence.RollbackException Failed to commit transaction: Attempt to reuse an existing primary key value (image.Meta:0) (error 613) at com.objectdb.jpa.EMImpl.commit(EMImpl.java:277) I check the db by explorer.jar, and find the only one record is id=0. What situation will be id=0? TIA #1 2011-08-26 05:26 Exception in thread "main" [ ObjectDB 2.2.9_04 ] javax. persistence . RollbackException Fai ...