About find

forum_thread

Drop the entire database, Change the schema

I am trying to port and example app to ObjectDb. As part of the tests I drop the database and reload it with the new schema automatically between test cycles. Is there a simple way to do this with ObjectDb, or is the only way to delete the database file everytime? Thanks ... and keeping the .odb allows the explorer to find the database more easily.       ...

 
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): ... enough - my fault after all. I am implementing my own find() function which was causing the failure because of a filter.. sorry!! ...

 
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 ...

 
issue

Issue with DISTINCT Select

It is getting more and more frustrating :( We've introduced distinct select instead of regular selection in our code (no changes else) and suddenly receive invalid identifiers in queries exceptions in various queries. Here's the stacktrace: ... $2 . lastName ) And attached you can find the according database for it. Try the query (without the TYPE($1)..() ...

 
forum_thread

Performance tuning, best practices

we have a system where we serve from a host process around 200 clients connected via webSockets (Jetty). The core process is running on a dedicated Windows 2012 server with 16 GByte RAM and 8 processor cores.  What is strange for us is that max 20% of the cpu resources are used and the IO subsystem is at maximum 30% of activity under heavy load but database queries are let's say not at the speed we would expect. We have currently 20.000.000 objects in the database, our configuration settings are: ... usually more complex and sometimes limited. If you find that a particular query is slow - the best way to improve performance is ...

 
forum_thread

Embedding ObjectDB on server application

I'm trying to integrate ObjectDB as part of a server software I am developing. I'm a little lost at the connection file path for the persistent factory. So if I want to pass in the database file path, with relative path, where exactly is it relative to? So I did a test and just wrote: EntityManagerFactory emf = Persistence.createEntityManagerFactory("test.odb"); But I got: Exception: javax.persistence.PersistenceException Message: No Persistence provider for EntityManager named test.odb #1 2014-06-02 13:11 I'm trying to integrate ObjectDB as part of a server software I am developing. I'm a little lost at the c ...

 
forum_thread

objectdb-2.6.9_02 (with "objectdb.temp.no-enhancement-crc-check") vs. generic classes with interfaces: detailed investigation

objectdb-2.6.9_02 (with "objectdb.temp.no-enhancement-crc-check" system property) The following is a detailed report on investigation of multiple issues that have been mentioned in the following forum postings and issue reports (but please do not visit them from here now, the diagnostics there are now obsolete): - Issue #282 - ObjectDB-2.6.9: Failed to commit transaction: Failed to set numeric value of field property Element.id using reflection ... for generics than the now-obsolete JAD. You can also find out about other Java decompilers (including a cloud-based service here ...

 
forum_thread

JPA vs JDO - which is more efficient for OneToMany queries?

I'm curious about the trade offs between JDO and JPA. Seems to me that JDO will perform better and be statically typed. For example: Assume there are Customers and Orders.... field has no value in the database, yet I can find all the orders thus: customerX.orders () instead of: "SELECT o FROM Order ...

 
forum_thread

Externalising persistence.xml properties in Glassfish?

Hi, ... you are using  but you should easily be able to find the start up script. This is the same place where heap size ect gets set. ...

 
issue

auto-generated uuid fields

Hello, we're porting a JDO application to ObjectDB which uses uuid-hex generated values. However the page on generated values in your JPA tutorial only mentions numeric generated values, and when we try to use it the error message seems to imply that auto-generating strings isn't supported. Could you confirm whether this is the case? If so it seems an odd omission, given that it's part of both the JPA and JDO standards (JPA Generator.UUID_HEX and JDO value-strategy="uuid-hex") and that the Java language itself supports it (java.util.UUID). ... was created). Thank you for your comments. If you find additional issues in supporting JDO please file issues using the "JDO ...