需要帮助优化使用Restrictions.In(..)的NHibernate条件查询吗

我试图找出是否有一种方法可以严格使用Criteria和DetachedCriteria,通过子查询或其他更优化的方法来执行以下操作。NameGuidDto只不过是一个具有字符串和Guid属性的轻量级对象。

public IList<NameGuidDto> GetByManager(Employee manager)
{
    // First, grab all of the Customers where the employee is a backup manager.
    // Access customers that are primarily managed via manager.ManagedCustomers.
    // I need this list to pass to Restrictions.In(..) below, but can I do it better?
    Guid[] customerIds = new Guid[manager.BackedCustomers.Count];

    int count = 0;
    foreach (Customer customer in manager.BackedCustomers)
    {
        customerIds[count++] = customer.Id;
    }

    ICriteria criteria = Session.CreateCriteria(typeof(Customer))
                                .Add(Restrictions.Disjunction()
                                                 .Add(Restrictions.Eq("Manager", manager))
                                                 .Add(Restrictions.In("Id", customerIds)))
                                .SetProjection(Projections.ProjectionList()
                                                          .Add(Projections.Property("Name"), "Name")
                                                          .Add(Projections.Property("Id"), "Guid"))

    // Transform results to NameGuidDto
    criteria.SetResultTransformer(Transformers.AliasToBean(typeof(NameGuidDto)));

    return criteria.List<NameGuidDto>();
}