I am getting outofmemory error in my java application. On analyzing heapdump of the application , I find that presistent set object of hibernate is consuming nearly 1 GB heapspace.

Following are the mapping files I am using. EMSDataRecord class holds above mentioned set containing objects of EventRecords( Mapping file for this is pasted below EMSDataRecord). Primary key for EMSDataRecord is RECORD_ID. There is one to many relation in EMSDataRecord and EventRecord. I checked in the database. For one entry of EMSDataRecord , there are not more than 2 entries of EventRecords. So there is no reason why the set should be so huge.

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping>

<class
name="EMSDataRecord"
table="EM1_RECORD"
dynamic-update="true"
>

<id
name="RecordId"
type="java.lang.Long"
column="RECORD_ID"
>
<generator class="assigned" />
</id>

<!-- Please do not change the order of the fields CR005-->
<property
name="StreamName"
type="java.lang.String"
column="STREAM_NAME"
update="false"
/>

<property
name="OriginatingSystem"
type="java.lang.String"
column="ORIGINATING_SYSTEM"
update="false"
/>

<property
name="DestinationSystem"
type="java.lang.String"
column="DESTINATION_SYSTEM"
update="false"
/>

<property
name="LayoutName"
type="java.lang.String"
column="LAYOUT_NAME"
update="false"
/>

<property
name="ErrorCode"
type="java.lang.String"
column="ERROR_CODE"
update="false"
/>

<property
name="ErrorDesc"
type="java.lang.String"
column="ERROR_DESC"
update="false"
/>

<property
name="ErrorTimestamp"
type="java.util.Date"
column="ERROR_TIMESTAMP"
update="false"
/>

<property
name="EventTimestamp"
type="java.util.Date"
column="EVENT_TIMESTAMP"
update="false"
/>

<property
name="ResolutionStatus"
type="java.lang.Integer"
column="RESOLUTION_STATUS"
/>

<property
name="ResolutionReason"
type="java.lang.Integer"
column="RESOLUTION_REASON"
/>

<property
name="RecordStatus"
type="java.lang.Integer"
column="RECORD_STATUS"
/>

<property
name="LockStatus"
type="java.lang.Integer"
column="LOCK_STATUS"
/>

<property
name="RejectionRemark"
type="java.lang.String"
column="REJECTION_REMARK"
/>

<property
name="AssignmentRuleId"
column="ASSIGNMENT_RULE_ID"
type="java.lang.Long"
/>

<property
name="CorrectionRuleId"
column="CORRECTION_RULE_ID"
type="java.lang.Long"
/>

<property
name="GroupId"
type="java.lang.Long"
column="GROUP_ID"
/>

<property
name="UserId"
type="java.lang.Long"
column="USER_ID"
/>

<property
name="TeamId"
type="java.lang.Long"
column="TEAM_ID"
/>

<property
name="RecordType"
type="java.lang.Integer"
column="RECORD_TYPE"
/>
<!-- Performance Improvement - Save Without BLOB Change - Added additional attribute to make the attribute read only-->
<property
name="FieldsMap"
type="binary"
column="FIELD_MAP"
update="false"
/>

<property
name="LastUpdTimeStamp"
type="java.util.Date"
column="LAST_UPD_TIMESTAMP"
insert="false"
/>

<set name="EventRecords" lazy="false" cascade="none" inverse = "true" where = "event_type=504">
<key>
<column name="RECORD_ID" />
</key>

<one-to-many class="EventRecord"/>
</set>
</class>
</hibernate-mapping>

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping>

<class
name="EventRecord"
table="EM1_EVENT"
>
<id
name="EventId"
type="java.lang.Long"
column="EVENT_ID"
unsaved-value="any"
>
<generator class="sequence">
<param name="sequence">SEQ_EVENT_ID</param>
</generator>
</id>

<property
name="RecordId"
type="java.lang.Long"
column="RECORD_ID"
update="false"
/>

<property
name="EventType"
type="java.lang.Integer"
column="EVENT_TYPE"
update="false"
/>

<property
name="ChangedField"
type="java.lang.String"
column="CHANGED_FIELD"
update="false"
/>

<property
name="OldValue"
type="java.lang.String"
column="OLD_VALUE"
update="false"
/>

<property
name="NewValue"
type="java.lang.String"
column="NEW_VALUE"
update="false"
/>

<property
name="ChangeTimestamp"
type="java.util.Date"
column="CHANGE_TIMESTAMP"
update="false"
insert="false"
/>

<property
name="UserId"
type="java.lang.Long"
column="USER_ID"
update="false"
/>

<property
name="ChangeReason"
type="java.lang.Integer"
column="CHANGE_REASON"
update="false"
/>

</class>
</hibernate-mapping>