不推荐在分配语句句柄之后设置SQL_ATTR_REOPT属性。
It is not recommended to set SQL_ATTR_REOPT attribute after statement handle is allocated.
我们还注意到，在两个服务调用之前存在分配语句，该语句可能非常复杂。
We also note that there are assignment statements prior to the two service invocations, which may be arbitrarily complex. This leads to another requirement.
正如您在前面例子的屏幕快照中可以看到的，一些语句没有成本分配。
As you may have seen in the screenshots of the previous examples, some statements have no costs assigned to them.
应用推荐