弹性搜索中的范围与术语提升

时间:2012-06-08 09:02:38

标签: full-text-search elasticsearch

我正在努力按照我想要的方式在弹性搜索中提升工作量。

假设我有一些索引包含性别,兴趣和年龄的个人资料,让我们说我发现性别匹配最相关,那么兴趣和最不重要的标准就是用户的年龄。我期待下面的查询导致根据刚刚提到的原则对匹配的配置文件进行排序,但是当我执行它时,我首先得到一些男性,然后我得到50岁的女性安娜,然后是喜欢汽车的女性玛丽亚...为什么玛丽亚没有得到比安娜更高的分数?

{
    "query": {
        "bool" : {
            "should" : [
                { "term"  : { "gender" : { "term": "male", "boost": 10.0 } } },
                { "term"  : { "likes"  : { "term": "cars", "boost" : 5.0 } } },
                { "range" : { "age"    : { "from" : 50,    "boost" : 1.0 } } }
            ],
            "minimum_number_should_match" : 1
        }
    }    
}

提示将不胜感激,

斯坦


这些是执行的curl命令:

$ curl -XPUT http://localhost:9200/users/profile/1 -d '{
    "nickname" : "bob",
    "gender" : "male",
    "age" : 48,
    "likes" : "airplanes"
}'

$ curl -XPUT http://localhost:9200/users/profile/2 -d '{
    "nickname" : "carlos",
    "gender" : "male",
    "age" : 24,
    "likes" : "food"
}'

$ curl -XPUT http://localhost:9200/users/profile/3 -d '{
    "nickname" : "julio",
    "gender" : "male",
    "age" : 18,
    "likes" : "ladies"
}'

$ curl -XPUT http://localhost:9200/users/profile/4 -d '{
    "nickname" : "maria",
    "gender" : "female",
    "age" : 25,
    "likes" : "cars"
}'

$ curl -XPUT http://localhost:9200/users/profile/5 -d '{
    "nickname" : "anna",
    "gender" : "female",
    "age" : 50,
    "likes" : "clothes"
}'

$ curl -XGET http://localhost:9200/users/profile/_search -d '{
    "query": {
        "bool" : {
            "should" : [
                { "term" : { "gender" : { "term": "male", "boost": 10.0 } } },
                { "term" : { "likes" : { "term": "cars", "boost" : 5.0 } } },
                { "range" : { "age" : { "from" : 50, "boost" : 1.0 } } }
            ],
            "minimum_number_should_match" : 1
        }
    }    
}'

1 个答案:

答案 0 :(得分:13)

boost值不是绝对的 - 确定每个字词的相关性为combined with other factors

你有两个“性别”(我会假设),但有很多不同的“喜欢”。因此male被认为几乎无关紧要,因为它在您的数据中经常发生。但是,cars可能只会发生几次,因此被认为更具相关性。

此逻辑对于全文搜索非常有用,但对于枚举而言则不适用于枚举,这些枚举主要用作过滤器。

幸运的是,您可以使用omit_term_freq_and_positionsomit_norms在每个字段的基础上停用此功能。

尝试按如下方式设置映射:

curl -XPUT 'http://127.0.0.1:9200/test/?pretty=1'  -d '
{
   "mappings" : {
      "test" : {
         "properties" : {
            "likes" : {
               "index" : "not_analyzed",
               "omit_term_freq_and_positions" : 1,
               "omit_norms" : 1,
               "type" : "string"
            },
            "gender" : {
               "index" : "not_analyzed",
               "omit_term_freq_and_positions" : 1,
               "omit_norms" : 1,
               "type" : "string"
            },
            "age" : {
               "type" : "integer"
            }
         }
      }
   }
}
'

更新:完整的工作示例:

删除现有索引:

curl -XDELETE 'http://127.0.0.1:9200/users/?pretty=1'

使用新映射创建索引:

curl -XPUT 'http://127.0.0.1:9200/users/?pretty=1'  -d '
{
   "mappings" : {
      "profile" : {
         "properties" : {
            "likes" : {
               "index" : "not_analyzed",
               "omit_term_freq_and_positions" : 1,
               "type" : "string",
               "omit_norms" : 1
            },
            "age" : {
               "type" : "integer"
            },
            "gender" : {
               "index" : "not_analyzed",
               "omit_term_freq_and_positions" : 1,
               "type" : "string",
               "omit_norms" : 1
            }
         }
      }
   }
}
'

索引测试文档:

curl -XPOST 'http://127.0.0.1:9200/users/profile/_bulk?pretty=1'  -d '
{"index" : {"_id" : 1}}
{"nickname" : "bob", "likes" : "airplanes", "age" : 48, "gender" : "male"}
{"index" : {"_id" : 2}}
{"nickname" : "carlos", "likes" : "food", "age" : 24, "gender" : "male"}
{"index" : {"_id" : 3}}
{"nickname" : "julio", "likes" : "ladies", "age" : 18, "gender" : "male"}
{"index" : {"_id" : 4}}
{"nickname" : "maria", "likes" : "cars", "age" : 25, "gender" : "female"}
{"index" : {"_id" : 5}}
{"nickname" : "anna", "likes" : "clothes", "age" : 50, "gender" : "female"}
'

刷新索引(以确保搜索时可以看到最新的文档):

curl -XPOST 'http://127.0.0.1:9200/users/_refresh?pretty=1' 

搜索:

curl -XGET 'http://127.0.0.1:9200/users/profile/_search?pretty=1'  -d '
{
   "query" : {
      "bool" : {
         "minimum_number_should_match" : 1,
         "should" : [
            {
               "term" : {
                  "gender" : {
                     "boost" : 10,
                     "term" : "male"
                  }
               }
            },
            {
               "term" : {
                  "likes" : {
                     "boost" : 5,
                     "term" : "cars"
                  }
               }
            },
            {
               "range" : {
                  "age" : {
                     "boost" : 1,
                     "from" : 50
                  }
               }
            }
         ]
      }
   }
}
'

结果:

# {
#    "hits" : {
#       "hits" : [
#          {
#             "_source" : {
#                "nickname" : "bob",
#                "likes" : "airplanes",
#                "age" : 48,
#                "gender" : "male"
#             },
#             "_score" : 0.053500723,
#             "_index" : "users",
#             "_id" : "1",
#             "_type" : "profile"
#          },
#          {
#             "_source" : {
#                "nickname" : "carlos",
#                "likes" : "food",
#                "age" : 24,
#                "gender" : "male"
#             },
#             "_score" : 0.053500723,
#             "_index" : "users",
#             "_id" : "2",
#             "_type" : "profile"
#          },
#          {
#             "_source" : {
#                "nickname" : "julio",
#                "likes" : "ladies",
#                "age" : 18,
#                "gender" : "male"
#             },
#             "_score" : 0.053500723,
#             "_index" : "users",
#             "_id" : "3",
#             "_type" : "profile"
#          },
#          {
#             "_source" : {
#                "nickname" : "anna",
#                "likes" : "clothes",
#                "age" : 50,
#                "gender" : "female"
#             },
#             "_score" : 0.029695695,
#             "_index" : "users",
#             "_id" : "5",
#             "_type" : "profile"
#          },
#          {
#             "_source" : {
#                "nickname" : "maria",
#                "likes" : "cars",
#                "age" : 25,
#                "gender" : "female"
#             },
#             "_score" : 0.015511602,
#             "_index" : "users",
#             "_id" : "4",
#             "_type" : "profile"
#          }
#       ],
#       "max_score" : 0.053500723,
#       "total" : 5
#    },
#    "timed_out" : false,
#    "_shards" : {
#       "failed" : 0,
#       "successful" : 5,
#       "total" : 5
#    },
#    "took" : 4
# }

更新:替代方法

在这里,我提出了一个替代查询,虽然更详细,但却能为您提供更可预测的结果。它涉及使用custom filters score query。首先,我们将文档过滤到与至少一个条件匹配的文档。由于我们使用constant score查询,因此所有文档的初始得分均为1。

自定义过滤器分数允许我们在每个文档与过滤器匹配时对其进行提升:

curl -XGET 'http://127.0.0.1:9200/_all/_search?pretty=1'  -d '
{
   "query" : {
      "custom_filters_score" : {
         "query" : {
            "constant_score" : {
               "filter" : {
                  "or" : [
                     {
                        "term" : {
                           "gender" : "male"
                        }
                     },
                     {
                        "term" : {
                           "likes" : "cars"
                        }
                     },
                     {
                        "range" : {
                           "age" : {
                              "gte" : 50
                           }
                        }
                     }
                  ]
               }
            }
         },
         "score_mode" : "total",
         "filters" : [
            {
               "boost" : "10",
               "filter" : {
                  "term" : {
                     "gender" : "male"
                  }
               }
            },
            {
               "boost" : "5",
               "filter" : {
                  "term" : {
                     "likes" : "cars"
                  }
               }
            },
            {
               "boost" : "1",
               "filter" : {
                  "range" : {
                     "age" : {
                        "gte" : 50
                     }
                  }
               }
            }
         ]
      }
   }
}
'

您将看到与每个文档相关联的分数是很好的整数,可以很容易地追溯到匹配的子句:

# [Fri Jun  8 21:30:24 2012] Response:
# {
#    "hits" : {
#       "hits" : [
#          {
#             "_source" : {
#                "nickname" : "bob",
#                "likes" : "airplanes",
#                "age" : 48,
#                "gender" : "male"
#             },
#             "_score" : 10,
#             "_index" : "users",
#             "_id" : "1",
#             "_type" : "profile"
#          },
#          {
#             "_source" : {
#                "nickname" : "carlos",
#                "likes" : "food",
#                "age" : 24,
#                "gender" : "male"
#             },
#             "_score" : 10,
#             "_index" : "users",
#             "_id" : "2",
#             "_type" : "profile"
#          },
#          {
#             "_source" : {
#                "nickname" : "julio",
#                "likes" : "ladies",
#                "age" : 18,
#                "gender" : "male"
#             },
#             "_score" : 10,
#             "_index" : "users",
#             "_id" : "3",
#             "_type" : "profile"
#          },
#          {
#             "_source" : {
#                "nickname" : "maria",
#                "likes" : "cars",
#                "age" : 25,
#                "gender" : "female"
#             },
#             "_score" : 5,
#             "_index" : "users",
#             "_id" : "4",
#             "_type" : "profile"
#          },
#          {
#             "_source" : {
#                "nickname" : "anna",
#                "likes" : "clothes",
#                "age" : 50,
#                "gender" : "female"
#             },
#             "_score" : 1,
#             "_index" : "users",
#             "_id" : "5",
#             "_type" : "profile"
#          }
#       ],
#       "max_score" : 10,
#       "total" : 5
#    },
#    "timed_out" : false,
#    "_shards" : {
#       "failed" : 0,
#       "successful" : 20,
#       "total" : 20
#    },
#    "took" : 6
# }