缓慢的top_hits聚合

Question

我有一个非常基本的top_hits聚合，但是如果结果集中的命中次数过多，则表现不佳（与返回大约一百次命中的平均命中集的搜索相比，这是另外一秒左右）。这是查询。

{
  "aggs": {
    "hits": {
      "aggs": {
        "children": {
          "top_hits": {
            "_source": "preview",
            "size": 3
          }
        },
        "top_score": {
          "max": {
            "script": "_score"
          }
        }
      },
      "terms": {
        "field": "rollupId",
        "size": 10,
        "order": {
          "top_score": "desc"
        }
      }
    }
  },
  "query": {
    "multi_match": {
      "query": "states",
      "fields": [
        "title^3",
        "nameText^2.5",
        "placeText^2",
        "allText"
      ],
      "type": "cross_fields",
      "operator": "and"
    }
  },
  "from": 0,
  "size": 0
}

我只想要10个结果，每个结果只有3次点击。为什么这么慢？