About optimistic


Transaction isolation support?

I am looking at using ObjectDB for our new project, and its looking good so far. But I have been unable to find any documentation about how transaction isolation is handled. For example: What happens If I am reading data in transaction A, and then transaction B commits while A is reading. (Especially if using LAZY fetch sub object). Do I always just get the list of objects as it looks when the fetch start? Martin   ... object using the first EntityManager , due the default optimistic locking (unless disabled in the configuration). You can ...


getObjectById(oid, validate)

This method locates a persistent instance in the cache of instances managed by this PersistenceManager.(Method of javax.jdo.PersistenceManager)



This interface is the point of contact between managed instances of PersistenceCapable classes and the JDO implementation.(Interface of JDO)


Pessimistic Lock Timeouts setting

Hi,   I realise that JPA2 doesn't necessarily define a standard API way for Lock Timeouts. However, there is a standardised query 'hint' that can be setup to make the underlying DB lock a record for a specific time. The hint property is: "javax.persistence.lock.timeout" ... for the prompt answers. In the meantime, I'll use an optimistic lock and fail on stale updates. ...


Criteria query error: Unexpected query token

Using JPA2, I can save entities now in JBoss, and also fetch them uniquely by id. However, if I try to fetch it by getting back all instances (e.g. findAll, I get the following error:   ... ;   /** * Version of object, supporting optimistic lock */ @ Column ( name = ...


Replication error on slave restart

I'm trying to enable replication on master server that was running with "recovery" enabled previously. I have copied database file to slave... and so on by manual. It worked fine. But if I restart slave server: ... on slave after step 3: com.objectdb.o.UserException: Optimistic lock failed (see multiple nested exceptions) at ...


Updating Entities

Hello, I'm currently writing a program using JavaFX and ObjectDB and I'm encountering a problem with Entities not sending their updates to each other. I have two Entities in question at the moment: Employee and Paygrade. ... Caused by: com.objectdb.o._OptimisticLockException: Optimistic lock failed for object application.model.Paygrade#184 (object has ...


[ODB1] Chapter 9 - ObjectDB Explorer

Explains how to view and manipulate database files in the database explorer. ... the Explorer starts. Transaction type (datastore or optimistic) on the open database (see Section 5.3 ). Whether or not ...



The Query interface allows applications to obtain persistent instances, values, and aggregate data from the data store.(Interface of JDO)