About @Version

forum_thread

Eager Fetch is not stable for collection or map types?

Hi, thanks very much for your helpful software. The problem is the storage of collection or map types is not stable, we lost them sometimes after JVM restarted. Eager fetch is properly set.And we still found that the storage is stable when we not use generic, such as "private List users = new ArrayList();" instead of "private List<User> users = new ArrayList<User>();".   The code about entity and fetch is: #1 2011-11-22 12:19 Hi, thanks very much for your helpful software. The problem is the storage of collection or map types is not ...

 
forum_thread

Should I use ObjectDB and JDO?

My application is not meeting required performance because JavaDB appears to be my bottleneck.  I require a faster DB.  Surveying the Internet lead me to believe that ObjectDB might be just what I am looking for (to achieve MUCH faster database access).  But, I have a few concerns.   #1 2016-07-09 15:19 My application is not meeting required performance because JavaDB appears to be my bottleneck.  I require a ...

 
manual

Index Definition

Describes how to define indexes in JPA entity classes and explains how indexes are used in JPQL queries. Querying without indexes requires iteration over entity objects in the database one by one. This may take a significant amount of time if many entity objects have to be examined. Using proper indexes the iteration can be avoided and complex queries ov ...

 
manual

Logical Operators in JPQL and Criteria API

Explains how to use AND, OR and NOT in JPQL queries. Logical operators in JPQL and in JPA criteria queries enable composition of complex JPQL boolean expressions out of simple JPQL boolean expressions. This page covers the following topics: Logical Operators ...

 
forum_thread

mappedBy problem

If I put the mappedBy element to the @OneToMany, the owned side (the many side) will never persist ! for example @Entity public class Employee { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) public Long id; public String name; @OneToMany(targetEntity=Address.class,mappedBy="employee") public List<Address> addresses; }   @Entity #1 2010-06-12 18:03 If I put the mappedBy element to the @OneToMany, the owned side (the many side) will never persist ! for exa ...

 
forum_thread

java.lang.NullPointerException when using ORDER BY

We are using ObjectDB 2.5.1_04. The following query causes an internal null pointer exception: SELECT r FROM RecordingMetaData AS r WHERE ((r.mapToCli != '192.168.10.200:9085' AND r.callDirection == 0)) ORDER BY r.startDateTime DESC If we remove the ORDER BY part, the query completes OK and returns the records from the DB, but obviously not in order. Here is the stack trace of the exception: #1 2014-02-20 00:59 We are using ObjectDB 2.5.1_04. The following query causes an internal null pointer exception: SELECT ...

 
forum_thread

In memory processing for ObjectDB

Hi there ! We are building a platform for trades processing where we want to keep our processing speeds very high. We like ObjectDb because its simplicity and the performance benchmarks, but to take it to next level really we wanted to check whether is there any In memory mode available for ObjectDB where recovery is possible, something like prevalyer etc. #1 2013-09-25 08:33 Hi there ! We are building a platform for trades processing where we want to keep our processing speeds v ...

 
forum_thread

100% CPU when using multiple BETWEEN

Hi, we are evaluating ObjectDB 2.5.1_03 in embedded mode. We have a DB of about 2800 instances of a class that has two java.lang.String members: toExtension and fromExtension. There are other members in the class, but not relevant to the problem.   A query like this cause the java process to start running at 100% CPU (endless loop) and it never recovers: #1 2013-07-17 03:49 Hi, we are evaluating ObjectDB 2.5.1_03 in embedded mode. We have a DB of about 2800 instances of ...

 
forum_thread

Configuration and Activation Code in ObjectDB 2.x

Hi ,   I would like to update the ObjectDB from 1.0 to 2.3.7_25. I used the License key for activating the odbee.jar file and got the activation code.It is mentioned in the side that i need to use the activation code using <activation> tag in the objectdb.conf file. In 1.x objectDB, we are not using any objectDB.conf file, we are just using setProperty method to set the different property e.g. properties.setProperty("javax.jdo.PersistenceManagerFactoryClass","com.objectdb.jdo.PMF"); #1 2012-05-16 14:58 Hi, I would like to update the ObjectDB from 1.0 to 2.3.7_25. I used the License key for activating the o ...

 
forum_thread

Is 2 level cache in use?

Hi, Is there any way to check, if 2 level cache is in use? Right now I've done two things: 1. objectdb.conf with cache size is placed in WEB-INF directory of my web application. 2. persistence.xml was modified with: #1 2011-05-06 11:55 Hi, Is there any way to check, if 2 level cache is in use? Right now I've done two things: 1. ...