ES extended_stats 函数

在进行ES聚合分析的时候，发现了一个非常有用的函数,extended_stats，可以对聚合的结果进行更近一步的分析 ，常见的 count sum avg  min max 等都可以一目了然

GET cars/transactions/_search
{
  "size": 0,
  "aggs": {
    "makes": {
      "terms": {
        "field": "make",
        "size": 10
      },
      "aggs": {
        "stats": {
          "extended_stats": {
            "field": "price"
          }
        }
      }
    }
  }
}

结果如下

 {
   "took": 87,
   "timed_out": false,
   "_shards": {
     "total": 5,
     "successful": 5,
     "failed": 0
   },
   "hits": {
     "total": 8,
     "max_score": 0,
     "hits": []
   },
   "aggregations": {
     "makes": {
       "doc_count_error_upper_bound": 0,
       "sum_other_doc_count": 0,
       "buckets": [
         {
           "key": "honda",
           "doc_count": 3,
           "stats": {
             "count": 3,
             "min": 10000,
             "max": 20000,
             "avg": 16666.666666666668,
             "sum": 50000,
             "sum_of_squares": 900000000,
             "variance": 22222222.22222221,
             "std_deviation": 4714.045207910315,
             "std_deviation_bounds": {
               "upper": 26094.757082487296,
               "lower": 7238.5762508460375
             }
           }
         },
         {
           "key": "ford",
           "doc_count": 2,
           "stats": {
             "count": 2,
             "min": 25000,
             "max": 30000,
             "avg": 27500,
             "sum": 55000,
             "sum_of_squares": 1525000000,
             "variance": 6250000,
             "std_deviation": 2500,
             "std_deviation_bounds": {
               "upper": 32500,
               "lower": 22500
             }
           }
         },
         {
           "key": "toyota",
           "doc_count": 2,
           "stats": {
             "count": 2,
             "min": 12000,
             "max": 15000,
             "avg": 13500,
             "sum": 27000,
             "sum_of_squares": 369000000,
             "variance": 2250000,
             "std_deviation": 1500,
             "std_deviation_bounds": {
               "upper": 16500,
               "lower": 10500
             }
           }
         },
         {
           "key": "bmw",
           "doc_count": 1,
           "stats": {
             "count": 1,
             "min": 80000,
             "max": 80000,
             "avg": 80000,
             "sum": 80000,
             "sum_of_squares": 6400000000,
             "variance": 0,
             "std_deviation": 0,
             "std_deviation_bounds": {
               "upper": 80000,
               "lower": 80000
             }
           }
         }
       ]
     }
   }
 }