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How to do multithreading with embedded ObjectDB

Hi, I've tried to implement a counter with ObjectDB, but the following code doesn't work as expected: #1 2014-04-22 07:57 Hi, I've tried to implement a counter with ObjectDB, but the following code doesn't work as expec ...

 
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A few questions on object database design

I've been trying to model a database that stores data in an MMORPG. With ObjectDB, a lot of things are easier to perform. Intuitively, I created an entity class called player and stored everything about the player as embeddable classes. However, my colleague questions about this structure, since we would be looking at persisting data from the server every minute or two per player. He has stability issues with the ObjectDB if we are accessing the same table all the time.... performance by eliminating the need to persist and retrieve small pieces of data separately. On the other hand, if the entity ...

 
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How to add minutes to a Date with JPA2

Hi,  I have to sum to a date of minutes, and check the date obtained is greater than the current date. My idea is as follows: Calendar currentTime = Calendar.getInstance(); Date currenteDate = currentTime.getTime(); Expression<Date> dateCapture = root.get(Counter_.dateCapture); Expression<Integer> samplingPeriod = root.get(Counter_.samplingPeriod); Expression<Integer> delayMinutes  = cb.prod(samplingPeriod,3); //minutes to be added ... I decided to write a function on the database and retrieve it with the data function . This will not be a portable ...

 
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Lazy Init / Eager / Join Fetch collection strategy ? What to choose ?

Hello, I'm doing some tests to choose the best collection fetch strategy. I have entities with many lazy collections and i don't want to load them all. In JPA / Hibernate world it exist some tests demonstrating how to choose the best strategy. For example : http://zeroturnaround.com/rebellabs/how-to-use-jpa-correctly-to-avoid-complaints-of-a-slow-application/ In this article,join fetch seems to be the right choice. What about ObjectDb ? The implementation is totally different. #1 2015-06-09 21:12 Hello, I'm doing some tests to choose the best collection fetch strategy. I have entities wit ...

 
tutorial

Step 5: Add a JSP Page

Explains how to add a JSP to an Eclipse Spring MVC JPA web application project. In this step we will add the JSP that generates the guestbook HTML output: Open the [New JSP File] dialog box by right clicking WEB-INF under src/main/webapp (in the [Package Explorer] window), selecting  New > Other... > Web > JSP F ...

 
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ObjectDb Supports Clustering of Servers?

Hi,     I am new to ObjectDb. we have a scenario where we deploy the same application in more than one linux (Jobss) servers. In this case user request can go to any server depends on the availability of the servers (This is for load balancing ). As of now we are using Oracle + Hibernate + JPA , as Oracle is shared data there was no problem. ... Object db server in my local too.  But when i retrieve objects from my local DB it was too fast where as it is taking so much ...

 
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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. #1 2014-06-10 08:02 Hello, I have just updated my objectdb version from 2.4.6 to 2.5.5. I observed a new bug or a fea ...

 
tutorial

Step 5: Add a JSP Page

Explains how to add a JSP to a NetBeans Spring MVC JPA web application project. In this step we will add the JSP that generates the guestbook HTML output: Open the [New JSP File] dialog box by right clicking the WEB-INF node under the Web Pages node (in the [Projects] window) and selecting New > JSP ... En ...

 
tutorial

Step 3: Add a Context Listener Class

Explains how to add a servlet context listener (to manage an application scope EntityManagerFactory) in an Eclipse Web Application. The Guest entity objects will be stored in an ObjectDB database, which will be represented by a JPA's EntityManagerFactory javax.persistence.EntityManagerFactory JPA interface Interface used to interact with the entity manager ...

 
issue

Internal exception

Hello. We got the following stacktrace. Can you explain me what this internal exception means and why it was thrown? It only happens when the entities are enhanced. Best regards BTC ES   ... query (due to changes since last commit/flush) in order to retrieve the mapped by instances. The stack trace indicates a failure to ...