我有一个类似以下两个示例事件的json结构：
事件1

{
      "event":{
             "type" : "FooBarEvent"
             "kv":{
                "key1":"value1",
                "key2":"value2",
                "3":"three",
                "d":"4"
             }
      }
    }

事件2

{
      "event":{
             "type" : "FooBarEvent"
             "kv":{
                "key1":"value1",
                "key2":"value2000",
                "e": "4"
             }
      }
    }

请注意，我不知道哪些键和值是预先进来，我想聚合（计数）他们。两个事件的输出如下所示：

+-----------+------+-----------+--------+
| EventType | Key  | Value     | Amount |
+-----------+------+-----------+--------+
| Foobar    | key1 | value1    | 2      |
+-----------+------+-----------+--------+
| Foobar    | key2 | value1    | 1      |
+-----------+------+-----------+--------+
| Foobar    | key2 | value2000 | 1      |
+-----------+------+-----------+--------+
| Foobar    | 3    | three     | 1      |
+-----------+------+-----------+--------+
| Foobar    | d    | 4         | 1      |
+-----------+------+-----------+--------+
| Foobar    | e    | 4         | 1      |
+-----------+------+-----------+--------+

在雅典娜，有没有一种不改变json结构的方法来实现这一点？如何最好地Map和展平/查询结构？