About contains

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. ... also be loaded?  Or, perhaps the datastore file contains key-value pairs (an entities field and value) so an entity request ...

 
release

2.2.0

Release date: 2011-04-03 Download (3.99 MB) Binary:  objectdb-2.2.0.zip You should start by following a  tutorial or reading the manual ...

 
forum_thread

JSON serialization and __odbHidden members

Hi.. Building a REST API (Jersey-based one) I noticed that object object I serialize to JSON has a clone field with "__odbHidden" suffix, e.g.there's  "id" and "id__odbHidden" is also (unwantenly) present with the same value. In general, we can annotate fields to include/exclude them from JSON serialization, but since these fields are not declared in my classes, I have no idea how to tell marshaller to avoid them. ... (auto-generated) The LoginInfo class contains just 2 fields (String eMail & password with relevant ...

 
manual

Running JPA Queries

Explains how to use JPA to run Java Persistence Query Language (JPQL) queries.... depends on the content of the database. If the database contains multiple Country objects with the name 'Canada' (e.g. due ...

 
forum_thread

exception thrown when try to run explorer again?

hello , when i try to launch explorer.jar i got this error: #1 2012-08-23 15:52 hello , when i try to launch explorer.jar i got this error: /Users/apple/Downloads/objectdb-2.4.2_02/bin Ka ...

 
forum_thread

On initialisation of lists: impact on migration from EclipseLink to ObjectDB

I would like to draw the attention of those assessing migration from EclipseLink ORM to ObjectDB to a significant difference in the initialization of persistent lists, namely that EclipseLink injects a List implementation into the List field to be initialise it during EntityManager.persist(). So in EclipseLink the following works: public class HasListOfBlocks { .. ... The EclipseLink forums and many Java forums contains some quite heated debates on whether one should init an @OneToMany ...

 
forum_thread

ClassCastException of same object type

I have ObjectDB partially working with my project. At the moment it seems to be saving objects and retrieving objects ok in the main project. However, when I make a plugin for the project, the new objects are persisted but not retrieved. I get the following error: java.lang.ClassCastException: org.sportscoring.ssv.xc.core.XCCompetitorCount cannot be cast to org.sportscoring.ssv.xc.core.XCCompetitorCount ... When the query is run, debugging shows that "list" contains the XCCompetitorCount objects I persisted earlier. The ... if (!this.XCCompetitorCounts.contains(obj)) { ...

 
release

2.3.7

Release date: 2012-02-06 Download (5.38 MB) Binary:  objectdb-2.3.7.zip You should start by following a  tutorial or reading the manual ...

 
forum_thread

collection of embedded objects

1. In general, are there any restrictions of the use of @Embedded objects in collections, compared to @Entity? 2. If you have a large nested collection of @Embedded objects, and you remove the parent @Entity, does the remove cascade through the whole collection? 3. Is searching through collections of @Embedded objects more expensive (time) than searching through collections of @Entity? #1 2011-05-14 21:23 1. In general, are there any restrictions of the use of @Embedded objects in collections, compared to @Enti ...

 
manual

Database Schema Evolution

Explains how ObjectDB handles automatically schema changes. Modifications to entity classes that do not change their persistent field definitions (their schema) are transparent to ObjectDB. This includes adding, removing and modifying constructors, methods and non persistent fields. However, additions, deleti ...