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One transaction or two?

If I have a large number of objects to delete and then add to a PersistenceManager is it more efficient to do everything in one transaction or two? Currently my code looks like this: ... you are asking about add/remove operations rather than read operation (in which the L1 cache is important) - performance gain, if any, ... Reply Please read carefully the posting instructions - before posting to ...

 
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Multitenancy with discriminator

Hello, I have a very large business application that makes use of the Hibernate "Filters" feature and of the EclipseLink "Single Table Multitenancy with discriminator" feature in order to implement entities filtering based on a discriminator. Here is an example of one of my business objects: public class BusinessPartner {     protected String id;     protected Domain domain;     ... } ... database. The ObjectDB query engine should be able to read some configuration data and when filtering is required for a given entity ... Reply Please read carefully the posting instructions - before posting to ...

 
issue

EOFException

Not sure if you'll be able to help with this but I've had an application get into a state where it cannot access anything from the database - queries fail with the following exception: ... 2.3.3_06] javax.persistence.PersistenceException Failed to read from file ... by: com.objectdb.o.UserException: Failed to read from file ... Reply Please read carefully the posting instructions - before posting to ...

 
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Optimistic Locking

We are having problems with optimistic locking.  I made a simple test case to try to induce an optimistic lock.... I have two users logged on to our system.  They both read and display the same data.  Then I change the data with user 1 and ... Reply Please read carefully the posting instructions - before posting to ...

 
forum_thread

Broken @ManyToOne reference

Hi, I have objects of type A belonging to objects of type B, defined as follows: @MappedSuperclass public abstract class A {   @Id   @ManyToOne(fetch = FetchType.EAGER, cascade=CascadeType.ALL, optional=false)   private B b;   @Id   @Column(length = 36)   private String stringId; } @MappedSuperclass public abstract class B {   @Id   private String name; } ... : testobjectdb. Parent @ e425743 Parent reference read back : null Regards, Vladimir ... written: testobjectdb.Parent @ 76a9b9c Parent reference read back: testobjectdb.Parent @ 6ab30913   ...

 
forum_thread

using DbUnit with ObjectDb

Are there any examples about how to use DbUnit with ObjectDB? DbUnit requires access to a jdbc connection .. with other providers it's possible to extract the jdbc connection from the EntityManager, e.g. for Eclipselink / Postgres combination you can use the rather long-winded: IDatabaseConnection connection = new DatabaseConnection(((EntityManagerImpl) (em2.getDelegate())).getServerSession().getAccessor().getConnection(), "PUBLIC"); but with objectDb this gives: ... attribute names vary from table to table .. not so easy to read via JAXB?? b) Entity driven approach: JPA entity classes ... to xml file should be easy - a generic mechanism to read / unmarshall those files into lists of entities for writing to database ...

 
issue

NullPointer when accessing entity field

Hello, following exception occurs when using objectdb: ... using EntityManagers in following way: for single read/write/update/delete: - we create new EntityManager, do the ... Reply Please read carefully the posting instructions - before posting to ...

 
forum_thread

'DROP TABLE' in ODB?

Let's say I no longer need some entity in my project and after deleting all the objects of this type in database I want to remove this type from schema. How can I do this? Is there something like SQL 'drop table' in ODB? ... --> Class Management There I also read that you can load new kind of compiled classes into the schema? But under ... Reply Please read carefully the posting instructions - before posting to ...

 
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Modifier operations

Hi, Today I was reading about different NoSQL databases. One of those database - MongoDB - has a very nice feature, especially for web applications - modifier operations. The whole trick for those operations is to change some value in object without pulling this object from database. So for example we have class: public class WebVisit { public String url; // key public int visitsCount; } As for now I have to pull this class from database: ... Reply Please read carefully the posting instructions - before posting to ...

 
forum_thread

java.io.IOException: Illegal seek

The Exception throws between whiles, is a bug?(ObjectDB 2.3.4_05) ... Caused by: com.objectdb.o.UserException: Failed to read from file ... Reply Please read carefully the posting instructions - before posting to ...