About PESSIMISTIC_WRITE
Locking in JPA
Explains how to use optimistic locking and pessimistic locking in JPA.... - which represents a shared lock. PESSIMISTIC_WRITE LockModeType.PESSIMISTIC_WRITE enum constant Pessimistic write lock. See ...
LockModeType.PESSIMISTIC_WRITE
Pessimistic write lock.(Enum Constant of javax.persistence.LockModeType)
javax.persistence.LockModeType
Lock modes can be specified by means of passing a LockModeType argument to one of the javax.persistence.EntityManager methods that take locks (lock, find, or refresh) or to the Query.setLockMode() or TypedQuery.setLockMode() method.(Enum of JPA)
Setting and Tuning of JPA Queries
Explains various JPA query settings - result range, flush and lock.... method. See JavaDoc Reference Page... . PESSIMISTIC_WRITE LockModeType.PESSIMISTIC_WRITE enum constant Pessimistic write lock. See ...
Pessimistic lock timeout - blocks indefinitely
I've attached a simple test which creates an object then kicks off several threads which each try to update the object. I'm using a pessimistic lock with timeout as follows: ... ( MyEntity. class , 1 , LockModeType . PESSIMISTIC_WRITE , properties ) ; One thread manages to do ...
InternalException during producer/consumer scenario
Hi, I'm trying to use objectdb in a producer/consumer scenario. Producer threads put message objects into a table while consumer threads remove the objects based on age, priority, etc. There are 2 main motivations for using objectdb for this purpose rather than a queue or similar data structure: 1) The consumer can select the "next" object based on a range of potentially complex criteria. 2) The number of objects produced can be potentially exceed available memory so can be held on disk within the objectdb file. ... on a query with MaxResults set to 1 and LockMode set to PESSIMISTIC_WRITE. This results in the exceptions below. Could you ...
Threaded Test - Failed to commit transaction: Unexpected internal exception
Hi I'm trying to create a simple producer-consumer queue scenario but am getting the followin exception: ... ( LockModeType . PESSIMISTIC_WRITE ) . getSingleResult ( ) ; ...
