聚合数据分析global bucket:单个品牌与所有品牌销量对比

aggregation scope,一个聚合操作,必须在query的搜索结果范围内执行
出来两个结果,一个结果,是基于query搜索结果来聚合的;一个结果,是对所有数据执行聚合的

GET /tvs/sales/_search
{
  "size": 0,
  "query": {
    "term": {
      "brand": "长虹"
    }
  },
  "aggs": {
    "single_brand_avg_price": {
      "avg": {
        "field": "price"
      }
    },
    "all":{
      "global": {},
      "aggs": {
        "all_brand_avg_price": {
          "avg": {
            "field": "price"
          }
        }
      }
    }
  }
}

global: 就是global bucket,就是将所有数据纳入聚合的scope,而不管之前的query

{
  "took": 14,
  "timed_out": false,
  "_shards": {
    "total": 3,
    "successful": 3,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 3,
    "max_score": 0,
    "hits": []
  },
  "aggregations": {
    "all": {
      "doc_count": 8,
      "all_brand_avg_price": {
        "value": 2650
      }
    },
    "single_brand_avg_price": {
      "value": 1666.6666666666667
    }
  }
}

single_brand_avg_price: 就是针对query搜索结果执行的,拿到的就是长虹品牌的平均价格
all_brand_avg_price: 拿到所有品牌的平均价格