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forum_thread

Can you implement fastest Native JPA for MySQL by ClusterJ like?

Hello , I've read some docs : http://biemond.blogspot.com/2010/04/super-fast-jpa-with-mysql-cluster-and.html http://dev.mysql.com/doc/ndbapi/en/mccj-using-jpa.html   ... Hello , I've read some docs : ... Reply Please read carefully the posting instructions - before posting to ...

 
forum_thread

Understanding limitations of schema evolution

Hi, I am trying to understand the limitations of schema evolution and have read the material on http://www.objectdb.com/java/jpa/entity/schema as well as the link therein regarding manual schema update when changing a field’s name Yet, i am confused regarding how to handle the case where one re-factors a class by moving one if it's Fields to a different class. Is this case managable? Thanks... to understand the limitations of schema evolution and have read the material on http://www.objectdb.com/java/jpa/entity/schema as well as ... Reply Please read carefully the posting instructions - before posting to ...

 
issue

How to change properties in urls2.xml ?

Hello, I am using objectdb in an embedded case with network private access to each database. I see it exists a file name "urls2.xml". <url><main>/var/lib/tomcat7/db/myDb.odb;user=admin;password=admin</main><alt>objectdb://127.0.0.1:38059/;user=$code;password=a2e54ea3-d889-41a7-953c-dabc42877742</alt></url> This file is autogenerated by objectdb. And it describes the locals databases url and their port / user / password properties. ... forum and not to the issue tracking system. Please read and follow the posting instructions . The post was moved to the ... Reply Please read carefully the posting instructions - before posting to ...

 
forum_thread

Debuging query before execution

Hi, Is is possible in any way to get string representation of a query right before execution, after setting parameters? Of course it's easy to print out query string when we build it by concatenating many strings, but even then we miss attributes. ... On the other hand multi line query can be tough to read from log files. I was thinking about this functionality in context of ... Reply Please read carefully the posting instructions - before posting to ...

 
issue

Typo in ObjectDB 1.0 Manual

Support > Knowledge Base > ObjectDB 1.0 Manual > Chapter 7 "JDOQL Queries" > Section 7.2 "Query Filter Syntax" > Subsection "Fields" > Second to last sentence Remove "not" from that sentence.   "An attempt to access a field or invoke a method using a null reference results in a false evaluation for the containing expression but no exception is not thrown."   ... manual.  It is very good and better than a JDO book I read because it focuses on giving essential information and not overloading the ... Reply Please read carefully the posting instructions - before posting to ...

 
forum_thread

Open several objectdb databases the same time

We tried to open objectdb databases from application and got following error: ... 4 more Is it possible to open object db files in read only mode from several application instances? ... What about database access performance (read/write speed) after re-configuring open a database with socket model? Do ...

 
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ClassCastException on closing PersistenceManager

Hi, I am using ObjectDB 2.6.3.b03 via JDO. Today I got the following exception while closing the PersistenceManager after reading the DB: ... 14:38 I just read ur answer. Once the bug appeared, it was coming also after restart of the ... Reply Please read carefully the posting instructions - before posting to ...

 
forum_thread

How to configure where the ODB is stored?

Hi, The documentation is lacking in this respect. How do I configure where the ObjectDB database file is stored. I need to know where it is so I can inspect it with 'database explorer'. The docs say to set it to "$objectdb/db/points.odb" and that this defaults to "the installation directory of ObjectDB". BUT... I DIDN'T INSTALL OBJECTDB - my maven build downloaded it and embeded it. So, where is this file stored??? Also, the contents of the DB don't seem to be persisted between AppServer restarts.  ... manual page . On that manual page you can also read how to change the ObjectDB Home. ObjectDB Support ... Reply Please read carefully the posting instructions - before posting to ...

 
forum_thread

find repeated records by JPQL

Hi, I know a single command in MySQL can find repeated records: Select * from TTT t where id in (select id from TTT s group id having count(id)>1) I dont know how to do this using JPQL, but I use query from 430,000 records and put them into hashmap, finally it cost one hour and failed: ... javax. persistence . PersistenceException Failed to read the value of field field image. URI . baURI using reflection ... com. objectdb . o . UserException : Failed to read the value of field field image. URI . baURI using reflection at ...

 
forum_thread

Multithreading Test and Deadlock

I move on to testing the multi threaded part of ObjectDB. From the same code (MyMain.java), I set the thread count from 1 to 4 and not only do I found it's slower overall (each thread only needs to insert 250K entities) but the threads are stuck with a deadlock. All threads share the same EntityManagerFactory but they have their own EntityManager. The stack trace is attached. ... Reply Please read carefully the posting instructions - before posting to ...