EntityManager in EJB3 CMT

Question

Hi
I'm getting a List of Entitys by
String _selectStr = "SELECT a FROM " + GNebenengGruppenverwEntity.class.getSimpleName() + "  a";
Query query = getEntityManager().createQuery(_selectStr);
return (Collection<GNebenengGruppenverwEntityIF>) query.getResultList();I'm getting them for read only purposes. But by getting them in this way they are managed by the entity manager. Every time about 13'000 Entitys are created and managed. If a User opens and closes the screan 3 times in a row the EntityManager tries to get these 13'000 Entitys parallel.
Is there a possibility to stop the entityManager from getting the List or at least say him he should get the list but do not manage them (whould at least save some memory).

Answer 1

If I use EntityManager.createNativeQuery(String) then I get results which are of course not bound in the entityManager but I have problems to Map all the returned Types like BigDecimal to something useful like Long. If I whould use EntityManager.createNativeQuery(String sql, String resultSetName) then this whould be handled, but is the returned Entity then again handled by the EntityManager?
And 2nd what I'm doing wrong? On the Entity I declared:
@SqlResultSetMapping(name="getList", entities={
    @EntityResult(entityClass = GNebenengGruppenverwEntity.class, fields = {
      @FieldResult(name = "NEG_KEY", column = "key")
      @FieldResult(name = "NEG_BEZEICHNUNG", column = "bezeichnung")
    })})and in the Bean I use:
String _selectStr = "SELECT kn.NEG_KEY key, kn.NEG_BEZEICHNUNG bezeichnung FROM re_nebenengagement kn";
final Query query = getEntityManager().createNativeQuery(_selectStr, "getList");
List result = query.getResultList();I always get
java.sql.SQLException: Ung�ltiger Spaltenname
and on the Output from JBoss I have:
DEBUG 2007-10-25 11:18:41,083 [AbstractBatcher] about to open PreparedStatement (open PreparedStatements: 0, globally: 0)
DEBUG 2007-10-25 11:18:41,083 [ConnectionManager] opening JDBC connection
DEBUG 2007-10-25 11:18:41,099 [SQL] SELECT kn.NEG_BEZEICHNUNG bezeichnung FROM kre_nebenengagement kn
DEBUG 2007-10-25 11:18:41,099 [AbstractBatcher] about to open ResultSet (open ResultSets: 0, globally: 0)
INFO 2007-10-25 11:18:41,099 *[LongType] could not read column value from result set: NEG1_39_0_; Ung�ltiger Spaltenname*DEBUG 2007-10-25 11:18:41,099 [AbstractBatcher] about to close ResultSet (open ResultSets: 1, globally: 1)
DEBUG 2007-10-25 11:18:41,099 [AbstractBatcher] about to close PreparedStatement (open PreparedStatements: 1, globally: 1)
DEBUG 2007-10-25 11:18:41,099 [ConnectionManager] aggressively releasing JDBC connection
DEBUG 2007-10-25 11:18:41,115 [ConnectionManager] releasing JDBC connection [ (open PreparedStatements: 0, globally: 0) (open ResultSets: 0, globally: 0)]
DEBUG 2007-10-25 11:18:41,115 [JDBCExceptionReporter] could not execute query [SELECT kn.NEG_BEZEICHNUNG bezeichnung FROM kre_nebenengagement kn]