About Persistence Context

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Listing large number of complicated objects with paging.

Hi, For last few hours I was working on a problem with bad performance and memory problems with such a simple query: select prod from Product prod order by prod.id ASC Right now I have 55541 'Product' (attached to this post) entities in database and I'm trying to speed listing them with paging. The problem is, that running code that looks like this: ... javax. jdo . annotations . *; import javax. persistence . *;   public class F294 { public ... Use ctrl + right click to open the browser context menu in the editing area (e.g. for using a browser spell ...

 
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Fetching Collections Puzzle

I am working on a project where I need to travel through a massive graph of objects. One of the main entity is the Node which is shown below. class Node { Node parent List<Node> children Node rightSibling Node leftSibling int rank } I have the following issues/doubts ... root Node. I have been looking for an optimum persistence solution for my project for quite some time now. I have tried every ... Use ctrl + right click to open the browser context menu in the editing area (e.g. for using a browser spell ...

 
issue

Exception in thread "ODB-StoreHandler-5094" java.lang.NullPointerException

Hi, ... Are transactions failing and receiving a a JPA Persistence exception?  Is there any risk of database corruption or data ... Use ctrl + right click to open the browser context menu in the editing area (e.g. for using a browser spell ...

 
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Query problem after transaction commit

I have a machine running the objectdb server and the client on another machine connect to it. The client program can connect to the server and query to get all the records. However, after transaction.begin ... persist(p) .. commit of a new object, my client program can no longer retrieve the old records but only the latest stored record. I tried to run database explorer on the server machine and able to see all the records including the new stored record.... Use ctrl + right click to open the browser context menu in the editing area (e.g. for using a browser spell ...

 
issue

NoResultException: No matching results for a unique query

I am very often getting a "com.objectdb.o._NoResultException: No matching results for a unique query" when modifying my already persisted entities within a transaction. I cannot replicate it however because it happens infrequently. The weird thing is that the entity nevertheless gets comitted perfectly right and all data is correctly written so I have no clue what's going on!?? Here's the stacktrace (copy+paste from debug output): ... Use ctrl + right click to open the browser context menu in the editing area (e.g. for using a browser spell ...

 
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Optimization Question

One of our uses for your ObjectDB software is in maintaining the current state of a large number of data objects called tracks. These tracks change very frequently over time (every 10-15 seconds is not unreasonable), but they are also very large complex data structures so it's extremely difficult to identify exactly what fields have changed from one update to the next. Currently the following sequence executes when a track update comes in: - If it’s a new track simply add it to the database.... Use ctrl + right click to open the browser context menu in the editing area (e.g. for using a browser spell ...

 
issue

Unable to stop server after starting in SSL mode

ObjectDB server starts & stops fine in non-SSL mode using start & stop shell scripts. ObjectDB server starts fine in SSL mode using start script but throws error and does not stop using stop shell script. Non-SSL mode server start/stop output: ObjectDB Server started on port 7032. ObjectDB Server stopped. SSL mode server start output: ObjectDB Server (SSL) started on port 7032. SSL mode server stop output: ... Use ctrl + right click to open the browser context menu in the editing area (e.g. for using a browser spell ...

 
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internal object DB locking in an embedded multi threaded application

Hi, we are using Embeded objectDB 2.4.4_06 in a highly multithreaded concurrent manner and we have noticed a performance problem in our application that seems to be attributed to ObjectDb's internal locking. When profiling our app in JVisualVm we notice a large number of threads are blocked and when doing a threaddump we notice that they are all blocked in the same place: ... Use ctrl + right click to open the browser context menu in the editing area (e.g. for using a browser spell ...

 
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lockfiles in client/server mode

i have an objectdb server running on localhost as user "objectdb", spawned like so: java -server -cp /usr/local/share/objectdb/objectdb.jar: com.objectdb.Server -conf /etc/objectdb/objectdb.conf start it has naturally created and taken ownership of /tmp/ObjectDB. ... machine where the objectdb server has done it. a persistence unit is defined in src/main/webapp/META-INF/persistence.xml with a ... Use ctrl + right click to open the browser context menu in the editing area (e.g. for using a browser spell ...

 
issue

Eager load Map

I'm having an issue eager loading a nested map. I've attached @ManyToMany(fetch=FetchType.EAGER) attributes to no avail. If the map is viewed in the debugger or force iterated in the code it loads ok. The attached code attempts to replicate the scenario. Its not an exact match but is the best I could come up with without replicating the whole system. The test creates an object, persists it to a db and re-loads it. The EntityManager is closed before accesing any fields. Finally the nested map is accessed and printed to screen. ... Use ctrl + right click to open the browser context menu in the editing area (e.g. for using a browser spell ...