具有分层类别、子类别的 Elasticsearch 聚合；限制水平

Question

我有类别字段的产品。使用聚合，我可以获得包含所有子类别的完整类别。我想限制 facet 中的级别。

例如我有这样的方面:

auto, tools & travel    (115)
auto, tools & travel > luggage tags (90)
auto, tools & travel > luggage tags > luggage spotters  (40)
auto, tools & travel > luggage tags > something else    (50)
auto, tools & travel > car organizers   (25)

像这样使用聚合

"aggs": {
    "cat_groups": {
      "terms": {
        "field": "categories.keyword",
        "size": 10,
       "include": "auto, tools & travel > .*"
      }
    }
}

我得到像这样的水桶

"buckets": [
        {
          "auto, tools & travel > luggage tags",
          "doc_count": 90
        },
        {
          "key": "auto, tools & travel > luggage tags > luggage spotters",
          "doc_count": 40
        },
        {
          "key": "auto, tools & travel > luggage tags > something else",
          "doc_count": 50
        },
        {
          "key": "auto, tools & travel > car organizers",
          "doc_count": 25
        }
]

但是我想限制等级。例如我只想获取 auto, tools & travel > luggage tags 的结果。我怎样才能限制级别？顺便说一句，"exclude": ".* > .* > .*" 对我不起作用。

我需要根据搜索获取不同级别的桶。有时是一级，有时是二级或三级。当我想要第一层时，我不希望第二层出现在桶上；以此类推。

Elasticsearch 6.4 版

Answer 1

我终于想出了下面的技术。

我已经使用 Path Hierarchy Tokenizer 实现了一个自定义分析器并且我创建了名为 categories 的多字段，以便您可以使用 categories.facets 进行聚合/构面，并使用 categories 进行普通文本搜索。

自定义分析器只适用于categories.facets

请注意我的字段 categories.facet

的属性 "fielddata": "true"

映射

PUT myindex
{
  "settings": {
    "analysis": {
      "analyzer": {
        "my_analyzer": {
          "tokenizer": "my_tokenizer"
        }
      },
      "tokenizer": {
        "my_tokenizer": {
          "type": "path_hierarchy",
          "delimiter": ">"
        }
      }
    }
  },
  "mappings": {
    "mydocs": {
      "properties": {
        "categories": {
          "type": "text",
          "fields": {
            "facet": { 
              "type":  "text",
              "analyzer": "my_analyzer",
              "fielddata": "true"
            }
          }
        }
      }
    }
  }
}

示例文档

POST myindex/mydocs/1
{
    "categories" : "auto, tools & travel > luggage tags > luggage spotters"
}

POST myindex/mydocs/2
{
    "categories" : "auto, tools & travel > luggage tags > luggage spotters"
}

POST myindex/mydocs/3
{
    "categories" : "auto, tools & travel > luggage tags > luggage spotters"
}

POST myindex/mydocs/4
{
    "categories" : "auto, tools & travel > luggage tags > something else"
}

查询

您可以尝试以下您正在寻找的查询。我再次实现了 Filter Aggregation因为您只需要特定的单词以及 Terms Aggregation .

{
  "size": 0,
  "aggs":{
    "facets": {
      "filter": { 
          "bool": {
            "must": [
              { "match": { "categories": "luggage"} }
            ]
         }
      },
      "aggs": {
        "categories": {
          "terms": {
            "field": "categories.facet"
          }
        }
      }
    }
  }
}

响应

{
    "took": 43,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": 11,
        "max_score": 0,
        "hits": []
    },
    "aggregations": {
        "facets": {
            "doc_count": 4,
            "categories": {
                "doc_count_error_upper_bound": 0,
                "sum_other_doc_count": 0,
                "buckets": [
                    {
                        "key": "auto, tools & travel ",
                        "doc_count": 4
                    },
                    {
                        "key": "auto, tools & travel > luggage tags ",
                        "doc_count": 4
                    },
                    {
                        "key": "auto, tools & travel > luggage tags > luggage spotters",
                        "doc_count": 3
                    },
                    {
                        "key": "auto, tools & travel > luggage tags > something else",
                        "doc_count": 1
                    }
                ]
            }
        }
    }
}

聊天讨论后的最终答案

POST myindex/_search
{
  "size": 0,
  "aggs":{
    "facets": {
      "filter": { 
          "bool": {
            "must": [
              { "match": { "categories": "luggage"} }
          ]
        }
      },
      "aggs": {
        "categories": {
          "terms": {
            "field": "categories.facet",
            "exclude": ".*>{1}.*>{1}.*"
          }
        }
      }
    }
  }
}

请注意，我添加了带有 正则表达式 的 exclude，这样它就不会考虑任何不止一次出现 的方面>

如果有帮助，请告诉我。