About reference

forum_thread

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: #1 2015-03-03 15:07 Hello, we have a performance problem when we use a large transaction. Let's do exactly the same i ...

 
forum_thread

Merge Issue: Attempt to reuse an existing primary key value

Hello, I have just updated my objectdb version from 2.4.6 to 2.5.5. I observed a new bug or a feature on an ordinary merge operation. This is the test case ( work in 2.4.6 version ) : 2 parents object share the same child on a ManyToMany relationship with Cascade.ALL constraint. ... ( tested with 2.4.5 ) : "Attempt to persist a reference to a non managed F799y$B instance". I was waiting to have 3 ...

 
manual

[ODB1] Chapter 8 - ObjectDB Server

An ObjectDB server can manage one or more databases. Databases that are managed by a server can be accessed by multiple processes simultaneously. In addition, the server supports accessing these databases from remote machines by TCP/IP. More details about client server mode vs. embedded database mode are discussed in Section 1.2. An ObjectDB server can manage one or more databases. Databases that are managed by a server can be accessed by multiple processes simultaneously. In addition, the server supports accessing these databases from remote machines by TCP/IP. More details abo ...

 
issue

[ObjectDB 2.5.5_03] Unexpected exception (Error 990)

Hello! When I run this query SELECT t FROM Unit t WHERE t.lastGeocodedPosition IS NULL OR t.lastGeocodedPosition.receiveTime < :lastGeocodedPosition.receiveTime I get the following exception: ... spec. I think that accessing a value field using a NULL reference is evaluated to either NULL or UNKNOWN,  Accessing an entity is ...

 
forum_thread

Type ... is not defined as an entity (@Entity is missing) (error 302)

Hello, I am using ObjectDB 2.2.8_08 with eclipse 3.6 and Groovy objects. I am attempting to persist an instance of CultureRqst in the project com.epimss.lab by using a Connection class imported from the project com.epimss.admin.   I can access the database OK, but attempting to persist the CultureRqst leads to the following exceptions: #1 2011-08-01 19:12 Hello, I am using ObjectDB 2.2.8_08 with eclipse 3.6 and Groovy objects. I am attempting to persi ...

 
forum_thread

locks on pure query activities

analyzing the dynamic behavior we can see from the thread dump that a lot of our threads that are just doing simple queries show locks like these (question is: why there are locks and how could we get rid of that):   log1:   #1 2017-04-28 09:28 analyzing the dynamic behavior we can see from the thread dump that a lot of our threads that are just doing simp ...

 
forum_thread

@Convert is not supported?

Does objectdb jpa implementation support @Convert annotation? (convertion of property before persistance and vice versa)   for example @Convert(converter = MyConverter.class) private Date date;   I've wrote a test on this, and seems that my Converters methods are not executed at all (like annotation doesent exist) ... one... meanwhile if DB did that before returning the reference I'd have no such problem please correct me if i'm ...

 
manual

[ODB1] Chapter 2 - A Quick Tour

Demonstrates basic database programming using ObjectDB. This chapter introduces basic ObjectDB and JDO concepts, using two sample programs. We start with the HelloWorld sample program, which is not JDO portable because it uses some ObjectDB extensions, but it is a good sample to start with because of its ...

 
forum_thread

Should I be able to persist a JFrame (or gui components in general)?

    I did the following: 1. (using Netbeans 8.02 & last available java 7 sdk) I sort of follow your tutorial(s) while applying the ideas to a sample that came with the IDE called GUIFormExamples (under samples). #1 2015-10-20 13:36     I did the following: 1. (using Netbeans 8.02 & last available java 7 sdk) I sort of fol ...

 
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: ... load the data set in packs, what happens with you have a reference to an entity object in a future pack that has not been handled yet? ...