OutOfMemory hibernate scroll with 2M records | Postgresql 8.4 DB

Hi

I am running a Criteria.scroll() on postgresql on a DB containing 2M
records. The memory keeps increasing and finally it generates an
OutOfMemoryException. Please can you advice how to fix this.

*Postgresql DB version:* 8.4
*Postgresql Driver Used:* postgresql-8.4-701.jdbc4.jar

Some forums do mention that "/scroll/" is slow on Postgresql.

Is this a known issue or we need to do something specific to make scroll
work on Postgresql?

It appears the driver class is loading all entity objects in memory and
not releasing them as expected in a scroll operation.

Appreciate any guidance/suggestion.

*Exception StackTrace*:
java.lang.OutOfMemoryError: Java heap space
at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Class.java:2291)
at java.lang.Class.getDeclaredField(Class.java:1880)
at
java.util.concurrent.atomic.AtomicReferenceFieldUpdater$AtomicReferenceFieldUpdaterImpl.<init>(AtomicReferenceFieldUpdater.java:181)
at
java.util.concurrent.atomic.AtomicReferenceFieldUpdater.newUpdater(AtomicReferenceFieldUpdater.java:65)
at java.sql.SQLException.<clinit>(SQLException.java:353)
at
org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1777)
at
org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257)
at
org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:479)
at
org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:367)
at
org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:271)
at
org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:93)
at
org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:186)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1787)
at org.hibernate.loader.Loader.scroll(Loader.java:2286)
at
org.hibernate.loader.criteria.CriteriaLoader.scroll(CriteriaLoader.java:89)
at org.hibernate.impl.SessionImpl.scroll(SessionImpl.java:1533)
at org.hibernate.impl.CriteriaImpl.scroll(CriteriaImpl.java:297)
at org.hibernate.impl.CriteriaImpl.scroll(CriteriaImpl.java:291)
at
com.hi.openname.dao.impl.HibernateKnowledgeItemDao.loadAllCommitted(HibernateKnowledgeItemDao.java:104)
at
com.hi.openname.dao.impl.HibernateKnowledgeItemDao.loadAllCommitted(HibernateKnowledgeItemDao.java:1)

Regards
Ankit