About READ
Locking in JPA
Explains how to use optimistic locking and pessimistic locking in JPA.... pessimistic lock modes are: PESSIMISTIC_READ LockModeType.PESSIMISTIC_READ enum constant Pessimistic read lock. See JavaDoc Reference ...
Failing to read entities under load in multithreaded tests
Hi, We are experiencing an issue in our application that only occurs under load - we sometimes fail to read entities from the database. ... that only occurs under load - we sometimes fail to read entities from the database. I've isolated this ... in multithreaded application it sometimes fails to read them from the DB with "No matching results for a unique query" error. ...
Error 363 - Failed to read value of inverse relationship
I've got two objects: @Entity public class EEvent { @Id @GeneratedValue(strategy = GenerationType.AUTO) private long id; @ManyToOne(optional=false) private ETown town; public ETown getTown() { return town; } public void setTown(ETown town) { this.town = town; } } And: ... expected in the Object DB Explorer, however when I try to read the Event type, I'm getting the following exception. As far as I can ... 2.2.0] javax.persistence.PersistenceException Failed to read the value of field com.pvdc.model.entity.EEvent.town using reflection ...
Error reading UTF string (Serialized Objects in Explorer)
This is the message I get for attached db and this query: ... have the serializable class, which is needed during read. Please check this query (and accessing that instance in general) ... Reply Please read carefully the posting instructions - before posting to ...
InternalException - error reading field from "queue" database
I trying to use an objectdb database as a persitent queue but have started getting the following error on the receiver side: ... by: com.objectdb.o._PersistenceException: Failed to read the value of field field ... 6 more Caused by: com.objectdb.o.UserException: Failed to read the value of field field ... Reply Please read carefully the posting instructions - before posting to ...
Optimistic locking failure
Optimistic locking failure: I am using a Semaphore to force this execution of concurrents transactions T1 and T2 that cause parallel updates to A/B but it does not throw an OptimisticLockException and roll back. ... READ ( A ) version = 1 value = 0 | READ ( B ) version = 1 value = 0 | | READ ( A ) version = 1 value = 0 ...
ObjectDB 2.3 Developer's Guide
Welcome to ObjectDB for Java/JPA Developer's Guide. Here you can learn how to develop database applications using ObjectDB and JPA (Java Persistence API). The main purpose of this guide is to make you productive with ObjectDB and JPA in a ...
What's next?
References to further reading about JPA and ObjectDB. This chapter introduced the basic principles of using JPA with ObjectDB. You can dive into the details by reading the other chapters of this manual. If you prefer to get started using ObjectDB right away you can follow one of these tutorials to creat ...
CacheStoreMode.USE
Insert/update entity data into cache when read from database and when committed into database: this is the default behavior.(Enum Constant of javax.persistence.CacheStoreMode)
