我如何在Elasticsearch中获得确切的总和？前参考我目前正在使用elasticsearch 5.6，我的索引映射如下所示：

{
  "my-index":{
    "mappings":{
      "my-type":{
        "properties":{
          "id":{
            "type":"keyword"
          },
          "fieldA":{
            "type":"double"
          },
          "fieldB":{
            "type":"double"
          },
          "fieldC":{
            "type":"double"
          },
          "version":{
            "type":"long"
          }
        }
      }
    }
  }
}

生成的搜索查询（使用Java客户端）为：

{
 /// ... some filters here
 "aggregations" : {
       "fieldA" : {
         "sum" : {
           "field" : "fieldA"
         }
       },
       "fieldB" : {
         "sum" : {
           "field" : "fieldB"
         }
       },
       "fieldC" : {
         "sum" : {
           "field" : "fieldC"
         }
       }
     }
}

但是，我的结果点击产生以下内容：

{
    "took": 10,
    "timed_out": false,
    "_shards": {
        "total": 3,
        "successful": 3,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": 5,
        "max_score": 3.8466966,
        "hits": [
            {
                "_index": "my-index",
                "_type": "my-type",
                "_id": "25a203b63e264fd2be13db006684b06d",
                "_score": 3.8466966,
                "_source": {
                    "fieldC": 108,
                    "fieldA": 108,
                    "fieldB": 0
                }
            },
            {
                "_index": "my-index",
                "_type": "my-type",
                "_id": "25a203b63e264fd2be13db006684b06d",
                "_score": 3.8466966,
                "_source": {
                    "fieldC": -36,
                    "fieldA": 108,
                    "fieldB": 144
                }
            },
            {
                "_index": "my-index",
                "_type": "my-type",
                "_id": "25a203b63e264fd2be13db006684b06d",
                "_score": 3.8466966,
                "_source": {
                    "fieldC": -7.2,
                    "fieldA": 1.8,
                    "fieldB": 9
                }
            },
            {
                "_index": "my-index",
                "_type": "my-type",
                "_id": "25a203b63e264fd2be13db006684b06d",
                "_score": 3.8466966,
                "_source": {
                    "fieldC": 14.85,
                    "fieldA": 18.9,
                    "fieldB": 4.05
                }
            },
            {
                "_index": "my-index",
                "_type": "my-type",
                "_id": "25a203b63e264fd2be13db006684b06d",
                "_score": 3.8466966,
                "_source": {
                    "fieldC": 36,
                    "fieldA": 36,
                    "fieldB": 0
                }
            }
        ]
    },
    "aggregations": {
        "fieldA": {
            "value": 272.70000000000005
        },
        "fieldB": {
            "value": 157.05
        },
        "fieldC": {
            "value": 115.64999999999999
        }
    }
}

为什么我得到：

115.64999999999999而不是字段C中的115.65 272.70000000000005而不是字段A中的272.7

我应该使用float而不是double？还是有一种方法可以更改查询而无需使用无痛脚本并使用具有指定精度和舍入模式的Java BigDecimal？