对 Elasticsearch 字段进行汇总和计数

Posted 2023-03-29

【中文标题】对 Elasticsearch 字段进行汇总和计数

【英文标题】：Sum and count aggregations over Elasticsearch fields

【发布时间】：2018-06-26 19:32:42

【问题描述】：

我是 Elasticsearch 的新手，我希望对 Elasticsearch 5.x 索引中的字段执行某些聚合。我有一个索引，其中包含具有字段langs（具有嵌套结构）和docLang 的文档。这些是动态映射的字段。以下是示例文档

文档 1：

   "_index":"A",
   "_type":"document",
   "_id":"1",
   "_source":
      "text":"This is a test sentence.",
      "langs":
         "X":
            "en":1,
            "es":2,
            "zh":3
         ,
        "Y":
            "en":4,
            "es":5,
            "zh":6
          
      ,
      "docLang": "en"
   

文档 2：

   "_index":"A",
   "_type":"document",
   "_id":"2",
   "_source":
      "text":"This is a test sentence.",
      "langs":
         "X":
            "en":1,
            "es":2
         ,
         "Y":
            "en":3,
            "es":4
          
      ,
      "docLang": "es"
   

文档 3：

   "_index":"A",
   "_type":"document",
   "_id":"2",
   "_source":
      "text":"This is a test sentence.",
      "langs":
         "X":
            "en":1
         ,
         "Y":
            "en":2
          
      ,
      "docLang": "en"
   

我想对 langs 字段执行求和聚合，这样对于每个键 (X/Y) 和每种语言，我都可以获得索引中所有文档的总和。另外，我想从docLang 字段中生成每种语言的文档数。

例如：对于以上 3 个文档，langs 字段的总和聚合如下所示：

"langs":  
      "X":  
         "en":3,
         "es":4,
         "zh":3
      ,
      "Y":  
         "en":9,
         "es":9,
         "zh":6
      
   

docLang 计数如下所示：

 "docLang":
    "en" : 2,
    "es" : 1
   

另外，由于一些生产环境限制，我无法在 Elasticsearch 中使用脚本。所以，我想知道是否可以对上述字段仅使用 field 聚合类型？

【参考方案1】：

  "size": 0,
  "aggs": 
    "X": 
      "nested": 
        "path": "langs.X"
      ,
      "aggs": 
        "X_sum_en": 
          "sum": 
            "field": "langs.X.en"
          
        ,
        "X_sum_es": 
          "sum": 
            "field": "langs.X.es"
          
        ,
        "X_sum_zh": 
          "sum": 
            "field": "langs.X.zh"
          
        
      
    ,
    "Y": 
      "nested": 
        "path": "langs.Y"
      ,
      "aggs": 
        "Y_sum_en": 
          "sum": 
            "field": "langs.Y.en"
          
        ,
        "Y_sum_es": 
          "sum": 
            "field": "langs.Y.es"
          
        ,
        "Y_sum_zh": 
          "sum": 
            "field": "langs.Y.zh"
          
        
      
    ,
    "sum_docLang": 
      "terms": 
        "field": "docLang.keyword",
        "size": 10
      
    
  

因为你没有提到，但我认为这很重要。我将X 和Y 设为nested 字段：

    "langs": 
      "properties": 
        "X": 
          "type": "nested",
          "properties": 
            "en": 
              "type": "long"
            ,
            "es": 
              "type": "long"
            ,
            "zh": 
              "type": "long"
            
          
        ,
        "Y": 
          "type": "nested",
          "properties": 
            "en": 
              "type": "long"
            ,
            "es": 
              "type": "long"
            ,
            "zh": 
              "type": "long"
            
          
        
      
    

但是，如果您的字段根本不是 nested，而这里我的意思实际上是 Elasticsearch 中的 nested 字段类型，那么像这样的简单聚合就足够了：

  "size": 0,
  "aggs": 
    "X_sum_en": 
      "sum": 
        "field": "langs.X.en"
      
    ,
    "X_sum_es": 
      "sum": 
        "field": "langs.X.es"
      
    ,
    "X_sum_zh": 
      "sum": 
        "field": "langs.X.zh"
      
    ,
    "Y_sum_en": 
      "sum": 
        "field": "langs.Y.en"
      
    ,
    "Y_sum_es": 
      "sum": 
        "field": "langs.Y.es"
      
    ,
    "Y_sum_zh": 
      "sum": 
        "field": "langs.Y.zh"
      
    ,
    "sum_docLang": 
      "terms": 
        "field": "docLang.keyword",
        "size": 10