About execute

forum_thread

Performance and memory usage of queries

Hello, we can't understand why the performance of queries is not the best and the execution requires so much memory. In the implementation of our UnitTests we have used "DELETE FROM Object" to delete the database. That did not work because we often get an "out of memory" exception. What's all done in the execution of queries? Why is so much memory is required, although from the application point of view, no object is loaded. #1 2015-03-10 09:22 Hello, we can't understand why the performance of queries is not the best and the execution requires ...

 
api-jpa

setLockMode(lockMode)

Set the lock mode type to be used for the query execution.(Method of javax.persistence.Query)

 
doc

java.lang.RuntimeException

(Exception of java.langException RuntimeException)

 
api-jdo

javax.jdo.JDODataStoreException

This class represents data store exceptions that can be retried.(Exception of JDO)

 
api-jdo

setRange(fromIncl, toExcl)

Set the range of results to return.(Method of javax.jdo.Query)

 
forum_thread

impossible to drop a table with 50 million objects

when trying to execute in explorer (max heap size 1GByte) delete from LogEntry l it comes up with a Java heap error after 20 minutes of executing. How to empty such a table ?     ... 05:49 when trying to execute in explorer (max heap size 1GByte) delete from LogEntry l ...

 
api-jpa

javax.persistence.EntityExistsException

Thrown by the persistence provider when EntityManager.persist(Object) is called and the entity already exists.(Exception of JPA)

 
api-jpa

javax.persistence.QueryTimeoutException

Thrown by the persistence provider when a query times out and only the statement is rolled back.(Exception of JPA)

 
api-jdo

javax.jdo.JDOOptimisticVerificationException

This class represents optimistic verification failures.(Exception of JDO)

 
api-jpa

construct(resultClass, selections)

Create a selection item corresponding to a constructor.(Method of javax.persistence.criteria.CriteriaBuilder)