match查询会将查询词分词,然后对分词的结果进行term查询。

bool查询原理

然后默认是将每个分词term查询之后的结果求交集,所以只要分词的结果能够命中,某条数据就可以被查询出来,而分词是在新建索引时指定的,只有text类型的数据才能设置分词策略。

新建索引,并指定分词策略:

PUT mail_test3
{
  "settings": {
    "index": {
      "refresh_interval": "30s",
      "number_of_shards": "1",
      "number_of_replicas": "0"
    }
  },
  "mappings": {
    "default": {
      "_all": {
        "enabled": false
      },
      "_source": {
        "enabled": true
      },
      "properties": {
        "addressTude": {
          "type": "text",
          "analyzer": "ik_max_word",
          "search_analyzer": "ik_smart",
          "copy_to": [
            "commonText"
          ],
          "fielddata": true
        },
        "captureTime": {
          "type": "long"
        },
        "commonText": {
          "type": "text",
          "analyzer": "ik_max_word",
          "search_analyzer": "ik_smart",
          "fielddata": true
        },
        "commonNum":{
          "type": "text",
          "analyzer": "ik_max_word",
          "search_analyzer": "ik_smart",
          "fielddata": true
        },
        "imsi": {
          "type": "keyword",
          "copy_to": ["commonNum"]
        },
        "uuid": {
          "type": "keyword"
        }
      }
    }
  }
}

analyzer 指的是在建索引时的分词策略,search_analyzer 指的是在查询时的分词策略。ik分词器还有一种ik_smart 的分词策略,可以比较两种分词策略的差别:

ik_smart分词策略:

GET mail_test3/_analyze
{
  "analyzer": "ik_smart",
  "text": "湖南省湘潭市江山路96号-11-8"
}

结果:

{
  "tokens": [
    {
      "token": "湖南省",
      "start_offset": 0,
      "end_offset": 3,
      "type": "CN_WORD",
      "position": 0
    },
    {
      "token": "湘潭市",
      "start_offset": 3,
      "end_offset": 6,
      "type": "CN_WORD",
      "position": 1
    },
    {
      "token": "江",
      "start_offset": 6,
      "end_offset": 7,
      "type": "CN_CHAR",
      "position": 2
    },
    {
      "token": "山路",
      "start_offset": 7,
      "end_offset": 9,
      "type": "CN_WORD",
      "position": 3
    },
    {
      "token": "96号",
      "start_offset": 9,
      "end_offset": 12,
      "type": "TYPE_CQUAN",
      "position": 4
    },
    {
      "token": "11-8",
      "start_offset": 13,
      "end_offset": 17,
      "type": "LETTER",
      "position": 5
    }
  ]
}

ik_max_word分词策略:

GET mail_test1/_analyze
{
  "analyzer": "ik_max_word",
  "text": "湖南省湘潭市江山路96号-11-8"
}

分词结果:

 {
  "tokens": [
    {
      "token": "湖南省",
      "start_offset": 0,
      "end_offset": 3,
      "type": "CN_WORD",
      "position": 0
    },
    {
      "token": "湖南",
      "start_offset": 0,
      "end_offset": 2,
      "type": "CN_WORD",
      "position": 1
    },
    {
      "token": "省",
      "start_offset": 2,
      "end_offset": 3,
      "type": "CN_CHAR",
      "position": 2
    },
    {
      "token": "湘潭市",
      "start_offset": 3,
      "end_offset": 6,
      "type": "CN_WORD",
      "position": 3
    },
    {
      "token": "湘潭",
      "start_offset": 3,
      "end_offset": 5,
      "type": "CN_WORD",
      "position": 4
    },
    {
      "token": "市",
      "start_offset": 5,
      "end_offset": 6,
      "type": "CN_CHAR",
      "position": 5
    },
    {
      "token": "江山",
      "start_offset": 6,
      "end_offset": 8,
      "type": "CN_WORD",
      "position": 6
    },
    {
      "token": "山路",
      "start_offset": 7,
      "end_offset": 9,
      "type": "CN_WORD",
      "position": 7
    },
    {
      "token": "96",
      "start_offset": 9,
      "end_offset": 11,
      "type": "ARABIC",
      "position": 8
    },
    {
      "token": "号",
      "start_offset": 11,
      "end_offset": 12,
      "type": "COUNT",
      "position": 9
    },
    {
      "token": "11-8",
      "start_offset": 13,
      "end_offset": 17,
      "type": "LETTER",
      "position": 10
    },
    {
      "token": "11",
      "start_offset": 13,
      "end_offset": 15,
      "type": "ARABIC",
      "position": 11
    },
    {
      "token": "8",
      "start_offset": 16,
      "end_offset": 17,
      "type": "ARABIC",
      "position": 12
    }
  ]
}

ik_max_word分词器的分词结果更多,分词的粒度更细,而ik_smart的分词结果粒度更粗,但较为智能。一般的策略是建立索引使用ik_max_word,查询时使用ik_smart,这样就能尽可能多的查到结果,而且上文提到,match查询最终是转化为term查询,因此只要某个分词结果命中,结果中就会有该条数据。

如果对搜索结果的精度较高,可以在查询中加入operator参数,然后让分词结果的每个term查询结果之间求交集,这样能尽可能地提高精度。

这里的operator设置为or和and的差别较大,可以测试进行比较:

GET mail_test3/_search
{
  "query": {
    "match": {
      "commonText": {
         "query": "湖北省宜昌市天台东二街",
         "operator": "and"
      }
    }
  }
}

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