ElasticSearch 使用filter時不對查詢關鍵字做分分詞，而query會。

這個可以通過以下實驗驗證。

DELETE /student
#創建student索引，並指定分詞器。這個分詞器看上去會同時應用於倒排索引建立時分詞和查詢關鍵字分詞。不##需要再指定缺省查詢分詞器：
#        "default_search": {
#          "type": "ik_max_word"
#        }
#但是官方文檔有提到可以單獨設置缺省查詢分詞器。
#https://www.elastic.co/guide/en/elasticsearch/reference/current/specify-analyzer.html
 
#創建student索引
PUT student
{
  "settings": {
    "analysis": {
      "analyzer": {
        "default": {
          "type": "ik_max_word"
        }
      }
    }
  }
}
 
#插入數據
 
POST /student/_doc/1
{
  "name":"徐小小",
  "address":"杭州",
  "age":3,
  "interests":"唱歌 畫畫  跳舞",
  "birthday":"2017-06-19"
}
 
POST /student/_doc/2
{
  "name":"劉德華",
  "address":"香港",
  "age":28,
  "interests":"演戲 旅遊 小",
  "birthday":"1980-06-19"
}
 
 
POST /student/_doc/3
{
  "name":"張小斐",
  "address":"北京",
  "age":28,
  "interests":"小品 旅遊 小米手機",
  "birthday":"1990-06-19"
}
 
POST /student/_doc/4
{
  "name":"王小寶",
  "address":"德州",
  "age":63,
  "interests":"演戲 小品 打牌 小米電視",
  "birthday":"1956-06-19"
}
 
POST /student/_doc/5
{
  "name":"向華強",
  "address":"香港",
  "age":31,
  "interests":"演戲",
  "birthday":"1958-06-19"
}
 
#通過query查詢"小米電器"，可以得到正確結果
 
GET student/_search
{
  "query": {
    "match": {
      "interests": "小米"
    }
  }
}
{
  "took": 15,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 2,
    "max_score": 0.6288345,
    "hits": [
      {
        "_index": "student",
        "_type": "_doc",
        "_id": "4",
        "_score": 0.6288345,
        "_source": {
          "name": "王小寶",
          "address": "德州",
          "age": 63,
          "interests": "演戲 小品 打牌 小米電視",
          "birthday": "1956-06-19"
        }
      },
      {
        "_index": "student",
        "_type": "_doc",
        "_id": "3",
        "_score": 0.2876821,
        "_source": {
          "name": "張小斐",
          "address": "北京",
          "age": 28,
          "interests": "小品 旅遊 小米手機",
          "birthday": "1990-06-19"
        }
      }
    ]
  }

而如果使用filter，則沒有任何結果。

GET /student/_search
{
  "query": {
    "bool": {
      "filter": {
        "term": {
         
          "interests": "小米電器"
        }
      }
    }
  }
}

{
  "took": 2,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 0,
    "max_score": null,
    "hits": []
  }
}

而查詢"小米"纔有結果

GET /student/_search
{
  "query": {
    "bool": {
      "filter": {
        "term": {
         
          "interests": "小米"
        }
      }
    }
  }
}

{
  "took": 2,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 2,
    "max_score": 0,
    "hits": [
      {
        "_index": "student",
        "_type": "_doc",
        "_id": "4",
        "_score": 0,
        "_source": {
          "name": "王小寶",
          "address": "德州",
          "age": 63,
          "interests": "演戲 小品 打牌 小米電視",
          "birthday": "1956-06-19"
        }
      },
      {
        "_index": "student",
        "_type": "_doc",
        "_id": "3",
        "_score": 0,
        "_source": {
          "name": "張小斐",
          "address": "北京",
          "age": 28,
          "interests": "小品 旅遊 小米手機",
          "birthday": "1990-06-19"
        }
      }
    ]
  }
}