About HAVING

forum_thread

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.... any given time, but then that defeats the whole point of having multiple threads. So yeah, without some intense analysis (we're ...

 
forum_thread

Is it possible to remove parent/child entities without refresh?

We have a big object tree in our project. If I use the entityManage.remove method a entityManager.refresh is necessary in order to have an updated object tree in memory. But entityManager.refresh is too slow for our project. Do you know a possibilty to remove parent/child entities without entityManager.refresh after the entityManager.remove operation? I have searched for a solution with the following unit test (See testRemoveVariant2()). But my approach works correctly. Do you have an idea? #1 2015-01-13 07:41 We have a big entity object tree in our project. If I use the entityManager.remove(childEntity) method to remove ...

 
issue

ArrayIndexOutOfBoundsException on flush

The following exception was thrown when my app attempted to flush an objectdb database: Bug Version: 1.04 Priority: Normal Status: Closed Replies: 11 Type:  Bug ...

 
forum_thread

How Should I Configure objectdb.conf to Obtain 256KB Disk IO Requests and Maximize Shared PersistenceManager Entity Cache?

These are questions asked in the context of the proposed architecture described in the forum thread titled, "Sample JDO Architecture for Follow Up Questions".   I tried to configure my objectdb.conf to give 256KB disk accesses and use PersistenceManager L1 ref=soft caching and datastore pagefile caching 1 MB (4 256KB sized pages).  The goal is to have frequent PersistenceManager L1 cache hit, then less frequent datastore pagefile cache hit, then when absolutely necessary, read/write from/to the disk, but in a 256 KB sized IO packets. ... 2016-07-26 07:56 Having larger database pages may have other effects (e.g. searching for an ... max performance at that size and reduces monetary fees by having fewer accesses). edit ...

 
forum_thread

@AttributeOverrides , and postgresql + own TYPE

Hello,  first of all i want to thank for this is site. I'm begginer in Java and also in JPA and this site is very helpful for me. Now What is my problem. Unfortunately  i have to work with postgresql + JPA + eclipselink, because is my school project. Database is final and i can't do any changes even if i wanted to. In structure of DB  is this. -- -- Name: address; Type: TYPE; Schema: artio; Owner: facman --   ... die in front my keyboard with trying. It is only one file, having 135 line. Very much thank you for your help and I hope for ...

 
forum_thread

using DbUnit with ObjectDb

Are there any examples about how to use DbUnit with ObjectDB? DbUnit requires access to a jdbc connection .. with other providers it's possible to extract the jdbc connection from the EntityManager, e.g. for Eclipselink / Postgres combination you can use the rather long-winded: IDatabaseConnection connection = new DatabaseConnection(((EntityManagerImpl) (em2.getDelegate())).getServerSession().getAccessor().getConnection(), "PUBLIC"); but with objectDb this gives: ... } I couldn't find a way around having to include the name of the entity as the XmlElement name .. but, ...

 
forum_thread

find() delay

Hi, I tried objectdb in following steps: 1, for 1 to 30 {trans.begin(); create typeC o; em.persist(o); trans.commit();} 2, for 1 to 30 {p = em.find(typeC.class, i); print(p)} So simple a test, there is no result in one go; I have to disable step 1 and run again, then Step 2 output the expected results. I tried em.flush(), em.clear(), etc.. that do not work. Any idea? TIA #1 2011-05-23 09:54 Hi, I tried objectdb in following steps: 1, for 1 to 30 {trans.begin(); create typeC o; em.persist(o); tr ...

 
forum_thread

OptimisticLockException

Have read read the documentation on optimistic locks, still not sure how to deal with these exceptions: [ObjectDB 2.2.5_04] javax.persistence.RollbackException Failed to commit transaction: Optimistic lock failed for object   ... have thought that would be done automatically. Having used objectdb for nearly 10 years now, all in embedded mode, I'm a ...

 
issue

Use temporary files to enable very large transactions

We have transactions in which many objects are created. These objects are no longer needed in the current transaction after creation. Unfortunately, we will receive an OutOfMemory exception because the objects are kept in the first level cache of ObjectDB. In the forum thread http://www.objectdb.com/database/forum/921 on post #4 you wrote, that ObjectDB should support very large transactions in further version. Can you implement it that ObjectDB used temporary files? Bug Version: 1.04 Priority: Critical Status: Fixed Replies: 27 Type:  Bug ...

 
forum_thread

Reading 1.x odb files in ObjectDB 2.x without upgrading

Hi, We have a problem in the backward compatibilty in our software as once we have migrated object db odb file from version 1.x to 2.x, user is unable to open the odb files in the application which is having object db 1.x installed. Is there any way to read odb files from 1.x in object db 2.x without upgrading it ? Or user can see the content in read only mode without upgrading it ? Thanks ... unable to open the odb files in the application which is having object db 1.x installed. Is there any way to read odb files ... result. Once i found that objectdb 1.x was having one row but after converting to objectdb 2.x, no row was present the odb ...