@Transactional
  public int removeByCategory(String categoryName) {
    TypedQuery<AmbariConfigurationEntity> query = entityManagerProvider.get().createNamedQuery(
        "AmbariConfigurationEntity.deleteByCategory", AmbariConfigurationEntity.class);
    query.setParameter("categoryName", categoryName);
    return query.executeUpdate();
  }
Removes the Ambari configuration properties with the requested category name from the database.

@param categoryName the configuration category name
@return the number of items removed
ambari-server/src/main/java/org/apache/ambari/server/orm/dao/AmbariConfigurationDAO.java