About performance

forum_thread

Source control of database

Hi, I'm new with ObjectDB. I want to know how I can evolve my model, adding new fields, new classes, perform refactors between versions, etc... There is something like http://www.liquibase.org that can I use over ObjectDB? #1 2017-09-28 19:18 Hi, I'm new with ObjectDB. I want to know how I can evolve my model, adding new fields, new classes, ...

 
forum_thread

mapping file is not being loaded

Hi, I am evaluating ObjectDB by using it with an in-house developed library in order to prototype its capabilities / performance. I am having a problem in that the in-house library in question reads a simple configuration file to determine available persistence units, and then bootstraps them using the JPA Persistance.createEntityManagerFactory() method and passing in the persistence unit name (again, obtained from the configuration file ). ... developed library in order to prototype its capabilities / performance. I am having a problem in that the in-house library in ...

 
forum_thread

Convert embedded database to server

Hello, What is the right way to convert an embedded database to a server one ? As a result, will a file "db.odb" exist ?  If no, where will be located db files ? Regards, Xirt   ... benefit of the embedded-server mode is of course better performance of the main application that accesses the database in embedded ...

 
tutorial

Step 3: Define a Spring DAO Component

Explains how to define a JPA DAO component (bean) in a NetBeans Spring MVC JPA web application project. Operations on the database will be performed by an instance of a Data Access Object (DAO) that we will define in this step as a Spring MVC component: Open the [New Java Class] dialog box by right clicking the guest packa ...

 
forum_thread

Strange behaviour with ORDER BY and IN

Hi, after trying out objectdb for a while now and being quite impressed by its speed and overall performance I noticed a strange behaviour where an ORDER BY - directive isn't executed as it should be (and usually is, except in this special combination-case). ... now and being quite impressed by its speed and overall performance I noticed a strange behaviour where an ORDER BY - directive ...

 
api-jpa

javax.persistence.Version

Specifies the version field or property of an entity class that serves as its optimistic lock value.(Annotation of JPA)

 
api-jdo

setSynchronization(sync)

The user can specify a Synchronization instance to be notified on transaction completions.(Method of javax.jdo.Transaction)

 
issue

Bulk load of eager mapped by (inverse) relationships

When a collection of objects is retrieved by ObjectDB (e.g. by a query) ordinary referenced objects and collection of objects that have to be loaded eagerly are loaded in bulk for better performance. However, inverse (mapped by) references that have to be loaded eagerly currently do not participate in a bulk load, which means that every reference requires running a separate query and doing a separate client-server round trip. Future versions of ObjectDB should load eager mapped by (inverse) fields in bulk as well. ... have to be loaded eagerly are loaded in bulk for better performance. However, inverse (mapped by) references that have to be ...

 
forum_thread

Cascading merge() leading to "Attempt to persist a reference to a non managed instance" error

Dear Support Using Objectdb 2.3.4_02 I ran into an exception while performing some tests with a parent/child relationship and cascading merge() operations. The parent has an application defined id, while the child's id is generated, but I don't know if this is of concern. The following "test case" reproduces the error: #1 2011-12-09 09:00 Dear Support Using Objectdb 2.3.4_02 I ran into an exception while performing some tests with a parent/ch ...

 
api-jdo

registerClass(pcClass, fieldNames, fieldTypes, fieldFlags, persistenceCapableSuperclass, pc)

Register metadata by class.(Static Method of javax.jdo.spi.JDOImplHelper)