About performance

manual

[ODB1] Chapter 5 - JDO Connections

The PersistenShows how to use database connections and transactions in JDO. ceManagerFactory interface represents a factory of database connections. Its main role is to provide PersistenceManager instances. The PersistenceManager interface represents a database connection. Every operation on a database requires a PersistenceManager instance. The Transaction interface represents a transaction on a database. Every operation that modifies the content of the database requires an active transaction.[toc hidden:1]... Usually the only difference between the two modes is in performance, where the default true value is expected to be slightly more ... Usually the only difference between the two modes is in performance. If rollback() is not so common, turning this flag off (using ...

 
manual

SELECT clause (JPQL / Criteria API)

Explains how to use the SELECT clause and projections in a JPA/JPQL query.... the required query results more precisely can improve performance and in some cases can also reduce the amount of Java code needed. ... Filtering duplicate results might have some effect on performance, depending on the size of the query result list and other factors. ...

 
manual

Locking in JPA

Explains how to use optimistic locking and pessimistic locking in JPA. JPA 2 supports both optimistic locking and pessimistic locking . Locking is essential to avoid update collisions resulting from simultaneous updates to the same data by two concurrent users. Locking in ObjectDB (and in JPA) is always at the da ...

 
forum_thread

@Convert is not supported?

Does objectdb jpa implementation support @Convert annotation? (convertion of property before persistance and vice versa)   for example @Convert(converter = MyConverter.class) private Date date;   I've wrote a test on this, and seems that my Converters methods are not executed at all (like annotation doesent exist) #1 2014-08-25 14:06 Does objectdb jpa implementation support @Convert annotation? (convertion of property before persistance and vice ...

 
manual

Database Connection using JPA

Describes the main JPA interfaces: EntityManagerFactory, EntityManager and EntityTransaction. Working with the Java Persistence API (JPA) consists of using the following interfaces: This page covers the following topics: Overview EntityManagerFactory EntityManager EntityTransac ...

 
forum_thread

Indexing a field results in internal Exception

I have an application that I have been converting from JPA/MySQL to JDO/ObjectDB and I have hit a problem with indexing. An index on a String field is required to give good performance but if I add the @Index annotation to the field I eventually end up with an ObjectDB internal exception.  This is reproducible, as is the program running to completion (slowly) if I remove the @Index annotation.  Is there anything I can look for that might result in this exception? ... An index on a String field is required to give good performance but if I add the @Index annotation to the field I eventually end up ...

 
release

2.0.5

... also inactive (new) indexes. Improved performance of database insert/update/delete operations. Changed default configuration (for improved performance). Added support for running a server with no tray ...

 
forum_thread

Object DB vs EclipseLink/TopLink: Unloaded relationships in detached entities

This topic is for those considering migrating from EclipseLink JPA or TopLink to ObjectDB JPA. ... desired collections (which requires some re-coding and has performance consequences when large relationship hierarchies are involved) to ...

 
release

2.0.3

... also inactive (new) indexes. Improved performance of database insert/update/delete operations. Changed default configuration (for improved performance). Added support for running a server with no tray ...

 
forum_thread

Connection performace after upgrade to objectdb 2

Hi, I have a problem with objectdb 2 when I tried to get the PersistenceManagerFactory and PersistenceManager : In objectdb 1 : PersistenceManagerFactory pmf = JDOHelper.getPersistenceManagerFactory(getProperties(physicalPath, objectName), JDOHelper.class.getClassLoader()); takes only 3ms PersistenceManager pm = pmf.getPersistenceManager(); takes 40ms However, with objectdb 2, the same instructions take respectively : 257ms and 238ms which is very expensive. ... Hi, I have performance problems with objectdb 2 when I tried to get the ... annotations for JPA/JDO, etc.) affect initialization performance (more files to look for and analyze), but without a realistic test ...