是否有某种回收Crystal Reports数据集的方法？

我正在尝试编写一个Crystal Report，该报告的汇总与主报表的分组方式不同。到目前为止，我唯一能够做到这一点的方法是对总计使用子报告，但这意味着必须再次击中数据源才能检索相同的数据，这似乎是胡说八道。这是一个简化的示例：

date   name   earnings   source          location
-----------------------------------------------------------
12-AUG-2008   Tom      $50.00   washing cars    uptown
12-AUG-2008   Dick    $100.00   washing cars    downtown     { main report }
12-AUG-2008   Harry    $75.00   mowing lawns    around town

                    total earnings for washing cars: $150.00 { subreport }
                    total earnings for mowing lawns:  $75.00

       date   name   earnings   source          location
-----------------------------------------------------------
13-AUG-2008   John     $95.00   dog walking     downtown
13-AUG-2008   Jane    $105.00   washing cars    around town  { main report }
13-AUG-2008   Dave     $65.00   mowing lawns    around town

                    total earnings for dog walking:   $95.00
                    total earnings for washing cars: $105.00 { subreport }
                    total earnings for mowing lawns:  $65.00

在此示例中，主报告按“日期”分组，但总计按“来源”分组。我查看了使用运行总计的示例，但它们并没有真正满足我的需求。是否没有某种存储结果集并使主报表和子报表都引用相同数据的方法？