Description of problem:

Attempt to delete huge number of partition events (more then 1 million events in the database) fails with error:
*******************************
10:29:07,685 ERROR [org.jboss.as.controller.management-operation] (http-/0.0.0.0:7080-72) JBAS014612: Operation ("read-attribute") failed - address: ([("deployment" => "rhq.ear")]): java.lang.OutOfMemoryError: GC overhead limit exceeded
    at java.util.LinkedHashMap.newNode(LinkedHashMap.java:256) [rt.jar:1.8.0_66]
    at java.util.HashMap.putVal(HashMap.java:630) [rt.jar:1.8.0_66]
    at java.util.HashMap.put(HashMap.java:611) [rt.jar:1.8.0_66]
    at java.util.HashSet.add(HashSet.java:219) [rt.jar:1.8.0_66]
    at org.jboss.as.controller.registry.AbstractModelResource.getChildren(AbstractModelResource.java:115) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.OperationContextImpl.readResourceFromRoot(OperationContextImpl.java:680) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.OperationContextImpl.readResource(OperationContextImpl.java:628) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.operations.global.ReadAttributeHandler.doExecuteInternal(ReadAttributeHandler.java:153) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.operations.global.ReadAttributeHandler.doExecute(ReadAttributeHandler.java:96) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.operations.global.GlobalOperationHandlers$AbstractMultiTargetHandler.execute(GlobalOperationHandlers.java:249) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.AbstractOperationContext.executeStep(AbstractOperationContext.java:702) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.AbstractOperationContext.doCompleteStep(AbstractOperationContext.java:537) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.AbstractOperationContext.completeStepInternal(AbstractOperationContext.java:338) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.AbstractOperationContext.executeOperation(AbstractOperationContext.java:314) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.OperationContextImpl.executeOperation(OperationContextImpl.java:1144) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.ModelControllerImpl.internalExecute(ModelControllerImpl.java:331) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.ModelControllerImpl.execute(ModelControllerImpl.java:188) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.jboss.as.controller.ModelControllerImpl$3.execute(ModelControllerImpl.java:563) [jboss-as-controller-7.5.3.Final-redhat-2.jar:7.5.3.Final-redhat-2]
    at org.rhq.common.jbossas.client.controller.JBossASClient.execute(JBossASClient.java:283) [rhq-jboss-as-dmr-client-4.12.0.JON330GA.jar:4.12.0.JON330GA]
    at org.rhq.common.jbossas.client.controller.DeploymentJBossASClient.getDeploymentPath(DeploymentJBossASClient.java:99) [rhq-jboss-as-dmr-client-4.12.0.JON330GA.jar:4.12.0.JON330GA]
    at org.rhq.enterprise.server.core.CoreServer.getEarDeploymentDir(CoreServer.java:187) [rhq-server.jar:4.12.0.JON330GA-redhat-4]
    at sun.reflect.GeneratedMethodAccessor156.invoke(Unknown Source) [:1.8.0_66]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.8.0_66]
    at java.lang.reflect.Method.invoke(Method.java:497) [rt.jar:1.8.0_66]
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71) [rt.jar:1.8.0_66]
    at sun.reflect.GeneratedMethodAccessor120.invoke(Unknown Source) [:1.8.0_66]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.8.0_66]
    at java.lang.reflect.Method.invoke(Method.java:497) [rt.jar:1.8.0_66]
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275) [rt.jar:1.8.0_66]
    at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:112) [rt.jar:1.8.0_66]
    at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:46) [rt.jar:1.8.0_66]
    at com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(MBeanIntrospector.java:237) [rt.jar:1.8.0_66]
*******************************

Version-Release number of selected component (if applicable):
RHQ 4.12

How reproducible:
Always

Steps to Reproduce:
1. Make sure that RHQ database - rhq_partition_event table contains more then a million events.
2. Attempt to delete partition events by clicking on "Purge All" button in RHQ UI -> Administration -> Partition Events page;
3.

Actual results:
Deletion of partition events fails.

Expected results:
Partition events are properly deleted.

Additional info:
"Purge All" - delete of partition events should be done using smaller batches.