json - Elasticsearch聚合过滤结果无法正常工作

Question

两个样本文件

POST / aggstest / test / 1

{
    "categories": [
        {
            "type": "book",
            "words": [
                {"word":"storm","count":277},
                {"word":"pooh","count":229}
            ]
        },
        {
            "type": "magazine",
            "words": [
                {"word":"vibe","count":100},
                {"word":"sunny","count":50}
            ]
        }
    ]
}

开机自检/ aggstest / test / 2

{
    "categories": [
        {
            "type": "book",
            "words": [
                {"word":"rain","count":160},
                {"word":"jurassic park","count":150}
            ]
        },
        {
            "type": "megazine",
            "words": [
                {"word":"tech","count":200},
                {"word":"homes","count":30}
            ]
        }
    ]
}

aggs查询

GET / aggstest / test / _search

{
  "size": 0,
  "query": {
    "filtered": {
      "filter": {
        "bool": {
          "must": [
            {
              "term": {
                "categories.type": "book"
              }
            },
            {
              "term": {
                "categories.words.word": "storm"
              }
            }
          ]
        }
      }
    }
  },
  "aggs": {
    "filtered": {
      "filter": {
        "bool": {
          "must": [
            {
              "term": {
                "categories.type": "book"
              }
            }
          ]
        }
      },
      "aggs": {
        "book_category": {
          "terms": {
            "field": "categories.words.word",
            "size": 10
          }
        }
      }
    }
  },
  "post_filter": {
    "term": {
      "categories.type": "book"
    }
  }
}

结果

{  
   "took": 5,  
   "timed_out": false,
   "_shards": {
      "total": 5,
      "successful": 5,
      "failed": 0
   },
   "hits": {
      "total": 1,
      "max_score": 0,
      "hits": []
   },
   "aggregations": {
      "filtered": {
         "doc_count": 1,
         "book_category": {
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [
               {
                  "key": "pooh",
                  "doc_count": 1
               },
               {
                  "key": "storm",
                  "doc_count": 1
               },
               {
                  "key": "sunny",
                  "doc_count": 1
               },
               {
                  "key": "vibe",
                  "doc_count": 1
               }
            ]
         }
      }
   }
}

========================

预期的aggs结果集不应包含“sunny”和“vibe”，因为它是“magazine”类型。

我使用了过滤器查询和post_filter，但我无法仅获得“book”类型的aggs结果。

Answer 1

您应用的所有过滤器(查询中和聚合中)仍将返回整个categories文档。本文档包含所有四个词，是汇总的范围。因此，您将始终获得所有4个存储桶。
据我了解，Elasticsearch 2.0版中的reducers将介绍一些在服务器端操作存储桶的方法。

您现在可以使用的是更改映射，以便categories为nested object。因此，您将能够独立查询它们，并使用嵌套聚合进行相应的聚合。将对象类型更改为嵌套需要重新索引。

另外请注意，post-filters不会应用于聚合。当您需要在比返回的匹配更大的范围内进行聚合时，它们可用于过滤原始查询而不会影响聚合。

还有一件事，如果查询中已经有过滤器，则无需将其放在聚合中，作用域已被过滤。