About @Entity

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Caching/Paging Questions...

Greetings ObjectDB team, All below questions assume a very large database (~1,000,000,000 objects): Q1: Two queries with a big overlap between their result sets. If I query the first set and hold the results in memory somehow, would that speed up the execution of the second query since many of its result objects already created and reside in memory ? #1 2011-01-02 04:12 Greetings ObjectDB team, All below questions assume a very large database (~1,000,000,000 objects): Q1: ...

 
tutorial

Step 4: Add a Controller Class

Explains how to add a servlet to a NetBeans Spring MVC JPA web application project. In this step we will add a Spring Controller to manage guestbook web requests: Open the [New Java Class] dialog box by right clicking the guest package node (in the [Projects] window) and selecting New > Java Class ... Enter Gu ...

 
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Non Embedded byte[]

I am trying to understand the "embedded=false" for JDO byte[] as described in ObjectDB 1.0 Manual, sections 4.3 and 4.4.   I desire to store an image as a byte[] but I don't want the byte[] to be loaded on the loading of the persistent object that has my image's attributes.  The byte[] would only be loaded from the datastore if my image's attribute evaluation deemed that it need to be loaded.   Can you give a JDO example of how to achieve this?   For example: #1 2016-07-28 15:25 I am trying to understand the "embedded=false" for JDO byte[] as described in ObjectDB 1.0 Manual, sections 4.3 a ...

 
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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 ...

 
tutorial

Step 4: Add a Controller Class

Explains how to add a servlet to an Eclipse Spring MVC JPA web application project. In this step we will add a Spring Controller to manage guestbook web requests: Open the [New Java Class] dialog box by right clicking the guest package node (in the [Package Explorer] window) and selecting  New > Class . The package n ...

 
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How to delete M2M relationship?

In user model class I have the following: public class User implements Serializable { #1 2013-08-06 19:19 In user model class I have the following: public class User implements Serializable { ...

 
forum_thread

Null Exception

An user reported me this exception. I am not sure how to reproduce it, but maybe it can help you somehow to solve it.  Object DB 2.4.4_05, embedded The important part is: #1 2012-11-04 09:43 An user reported me this exception. I am not sure how to reproduce it, but maybe it can help you to solve it some ...

 
forum_thread

DB Doctor sets type to "unknown" for new fields

Hi, we are using ObjectDB 2.5.4_04 on Linux. We added two new Boolean fields to a persistable type and run DB Doctor on the exiting DB file in order to update the schema. The fields are added to the schema as expected, however their type is set to unknown - we were expecting Boolean. The attached DB file is what was produced by DB Doctor after adding the emergency and broadcast fields. If you run in DB Explorer #1 2014-05-29 03:04 Hi, we are using ObjectDB 2.5.4_04 on Linux. We added two new Boolean fields to a persistable typ ...

 
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Out of memory

Hi, Today in the middle of the night ODB just crashed leaving this on console screen: #1 2012-09-18 07:06 Hi, Today in the middle of the night ODB just crashed leaving this on console screen: ObjectDB Serv ...

 
forum_thread

Deadlock in objectdb code

Running multi-threaded access to an embedded database using JDO, I'm getting a deadlock in objectdb code.  Thread dump attached. #1 2013-05-22 17:15 Running multi-threaded access to an embedded database using JDO, I'm getting a deadlock in objectdb code. &nb ...