About @Entity

forum_thread

JRebel integration feature

#1 2010-05-22 19:11 Feature request: Dynamic class enhancement during development compatible with JRebel. ...

 
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performance limit

Hi, can someone share expirience with performance limits of ObjectDB especialy when quering tables with large records sets. Our issue is with tables with 100.000+ records. Everything was OK when we had few thousand records. We have a simple SELECT statement which selects from a table with 100.000+ records by UserID atribute, tables have from 5 to 20 atributes. Usualy the results range from few hundred to few thousand records. This query takes up to 12 seconds. Is this normal, what when we will have few milion records, how to handle this. #1 2014-09-09 21:33 Hi, can someone share expirience with performance limits of ObjectDB especialy when quering tables with large rec ...

 
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Occasionally slow requests in load testing

We are running load testing against objectdb version 2.3.7_18. The performance is generally OK, however there are quite a few "spikes" in the performance where we are getting a lot of very slow response times from the DB, around 10 - 15 seconds. Looking at the DB server process with AppDynamics we can see that most of the requests get stuck in one of 2 places: com.objectdb.o.PGC:w: line number 232 com.objectdb.o.LFL:U: line number 1068 Please see the attached callgraph examples for full stack trace examples. #1 2012-04-26 12:56 We are running load testing against objectdb version 2.3.7_18. The performance is generally OK, however there are ...

 
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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 ...

 
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Enhancer problem

During development, I have used the enhancer API in a static block in the code that creates the EntityManagerFactory, ie. #1 2011-09-02 13:42 During development, I have used the enhancer API in a static block in the code that creates the EntityManagerFact ...

 
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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 ...

 
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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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: ...