Elasticsearch - 对没有特定字段的文档给予负面提升

Question

我正在处理一个查询，基本的过滤多重匹配查询按计划工作，它返回我想要的文档。

问题是想要提升具有 ex 的特定字符串字段的结果。 0.5，或者在本例中给出没有此字段“traded_as”的结果 1.0 的负提升。

无法让过滤器 - 提升 - 必须 - 存在/缺失才能按我的意愿工作。

这是解决这个问题的正确方法吗？

使用 Elasticsearch 1.5.2

{
"query": {
    "filtered": {
        "query": {
           "multi_match": {
               "query": "something",
               "fields": ["title", "url", "description"]
           }
        },
        "filter": {
           "bool": {
                "must": {
                    "missing": {
                        "field": "marked_for_deletion"
                    }
                }
            }
        }
    }
},
"boosting": {
    "positive": {
        "filter": {
            "bool": {
                "must": {
                    "exists": {
                        "field": "traded_as"                            
                    }
                }
            }
        }
    },
    "negative": {
        "filter": {
           "bool": {
                "must": {
                    "missing": {
                        "field": "traded_as"
                    }
                }
            }
        }
    },
    "negative_boost": 1.0
}
}

Answer 1

你不可能得到想要的结果。正如提升查询的文档中所述:

Unlike the "NOT" clause in bool query, this still selects documents that contain undesirable terms, but reduces their overall score.

{
  "query": {
    "boosting": {
      "positive": [{
        "filtered": {
          "query": {
            "multi_match": {
              "query": "something",
              "fields": ["title", "url", "description"]
            }
          },
          "filter": {
            "bool": {
              "must": [{
                "missing": {
                  "field": "marked_for_deletion"
                }
              }]
            }
          }
        }
      }],
      "negative": [{
        "filtered": {
          "filter": {
            "missing": {
              "field": "traded_as"
            }
          }
        }
      }],
      "negative_boost": 1.0
    }
  }
}

所以你仍然会有一些不相关的文档，但是匹配的文档会有更好的分数。那样的话，您不会对 traded_as 存在有任何提升。为此，您应该查看函数得分 http://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-function-score-query.html#_using_function_score

你会得到类似的东西

{
  "query": {
    "function_score": {
      "query": {
        "filtered": {
          "query": {
            "multi_match": {
              "query": "something",
              "fields": ["title", "url", "description"]
            }
          },
          "filter": {
            "bool": {
              "must": {
                "missing": {
                  "field": "marked_for_deletion"
                }
              }
            }
          }
        }
      },
      "functions": [{
        "filter": {
          "exists": {
            "field": "traded_as"
          }
        },
        "boost_factor": 2
      }, {
        "filter": {
          "missing": {
            "field": "traded_as"
          }
        },
        "boost_factor": 0.5
      }],
      "score_mode": "first",
      "boost_mode": "multiply"
    }
  }
}