ES全文檢索之intervals查詢_9_2_1

1、intervals查詢

intervals查詢使用了匹配規則,這些規則將會使用在指定字段的對應詞(term)上;
這些規則定義將產生橫跨文本的最小化的間隔(interval),這些間隔可以被父級間隔(interval)組合或過濾;

intervals查詢示例

//請求參數
GET software/_search
{
  "query": {
    "intervals": {
      "desc": {
        "all_of": {
          "ordered": true,
          "intervals": [
            {
              "match": {
                "query": "distributed search",
                "max_gaps": 0,
                "ordered": true
              }
            },
            {
              "any_of": {
                "intervals": [
                  {
                    "match": {
                      "query": "analytics engine"
                    }
                  },
                  {
                    "match": {
                      "query": "Elastic Stack"
                    }
                  }
                ]
              }
            }
          ]
        }
      }
    }
  }
}

intervals查詢頂級參數

序號	參數	描述
1	<field>	(必須)—希望搜索的文檔字段;該參數對應着規則對象,基於詞(term)、順序(order)以及相互間距離來匹配文檔;

2、intervals查詢關鍵字

合法的規則關鍵詞有以下幾類

序號	關鍵字	描述
1	match
2	prefix
3	wildcard
4	fuzzy
5	all_of
6	any_of

2.1、match規則參數說明

match規則匹配被分詞後的文本

具體匹配參數

序號	參數	描述
1	query	(必須,字符串類型)–指定需要查詢的文本信息
2	max_gaps	(可選,數值類型)—匹配詞(term)之間最大間隔,默認爲-1;未指定或指定爲-1則匹配無間隔限制,設置爲0則匹配詞必須要在已匹配詞的下個詞開始匹配(連續)
3	ordered	(可選,布爾類型)—值爲true表示匹配詞必須按照指定順序出現,默認爲false
4	analyzer	(可選,字符串類型)—指定查詢的分詞器,默認爲指定查詢字段對應的分詞器
5	filter	(可選,規則對象)—對應一個interval filter
6	use_field	(可選,字符串類型)—若指定該字段,則intervals查詢不使用上層轉而以該字段進行查詢,查詢使用的分詞器也是該字段對應的搜索分詞器;

2.2、prefix規則參數說明

prefix規則匹配的詞要以指定的字符串開頭,若prefix參數指定的字符串匹配超過128個詞(term)則ES將報錯,
這可以通過設置字段參數index_prefix來接觸該限制;

具體匹配參數

序號	參數	描述
1	prefix	(必須,字符串類型)—指定匹配詞(term)開頭的字符串
2	analyzer	(可選,字符串類型)—分詞器用於對前綴字符串進行normalize處理,默認爲上層指定的分詞器
3	use_field	(可選,字符串類型)—若指定該字段,則intervals查詢不使用上層轉而以該字段進行查詢

2.3、wildcard規則參數說明

wildcard規則使用通配符進行匹配,指定的通配符匹配超過128個則ES將報錯;

具體匹配參數

序號	參數	描述
1	pattern	(必須,字符串類型)—指定通配符;參數支持兩類通配符: ? 匹配單個字符; * 匹配零或多個字符,包括空字符
2	analyzer	(可選,字符串類型)—分詞器用於對通配符進行normalize處理,默認爲上層指定的分詞器
3	use_field	(可選,字符串類型)—若指定該字段,則intervals查詢不使用上層轉而以該字段進行查詢

2.4、fuzzy規則參數說明

fuzzy規則匹配與給定詞(term)相似詞(可編輯距離內的term)的匹配結果,若模糊匹配的詞(term)超過128個則ES將報錯;

具體匹配參數

序號	參數	描述
1	term	(必須,字符串類型)—需要匹配的詞
2	prefix_length	(可選,字符串類型)—創建擴展時起始字符數保持不變,默認起始字符數爲0
3	transpositions	(可選,布爾類型)—確定編輯時是否包括兩個相鄰字符的換位(ab->ba),默認爲true
4	fuzziness	(可選,字符串類)—匹配允許的最大編輯距離,默認爲auto
5	analyzer	(可選,字符串類型)—分詞器用於對term進行normalize處理,默認爲上層指定的分詞器
6	use_field	(可選,字符串類型)—若指定該字段,則intervals查詢不使用上層轉而以該字段進行查詢

2.5、all_of規則參數說明

all_of規則返回的匹配結果是跨越多個組合規則而得到的;

具體匹配參數

序號	參數	描述
1	intervals	(必須,對象數組)—需要組合的規則數組;所有規則都必須在文檔中產生匹配項以使最終有匹配文檔
2	max_gaps	(可選,數值類型)—匹配詞(term)之間最大間隔,默認爲-1;未指定或指定爲-1則匹配無間隔限制,設置爲0則匹配詞必須要在已匹配詞的下個詞開始匹配(連續)
3	ordered	(可選,布爾類型)—值爲true表示匹配詞必須按照指定順序出現,默認爲false
4	filter	(可選,規則對象)—對應一個interval filter

2.6、any_of規則參數說明

any_of規則匹配任何子規則的文檔;

具體匹配參數

序號	參數	描述
1	intervals	(必須,對象數組)—需要任一匹配的規則數組;
2	filter	(可選,規則對象)—對應一個interval filter

2.6、filter規則參數說明

filter規則是基於查詢返回intervals;

具體匹配參數

序號	參數	描述
1	after	(可選,查詢對象)—query的interval在filter的interval之後
2	before	(可選,規則對象)—query的interval在filter的interval之前
3	contained_by	(可選,查詢對象)—filter中的interval包含query的interval
4	containing	(可選,查詢對象)—query的interval包含filter的interval
5	not_contained_by	(可選,查詢對象)—filter中的interval不包含query的interval
6	not_containing	(可選,查詢對象)—query的interval不包含filter的interval
7	not_overlapping	(可選,查詢對象)—filter中的interval與query的interval不重疊
8	overlapping	(可選,查詢對象)—filter中的interval與query的interval相互重疊
9	script	(可選,腳本對象)—腳本用於返回匹配的文檔

//以下查詢包含filter規則,有兩個限制條件:
//1、要求desc字段查詢時指定的query字段中兩個詞相隔不得超過3個位置(max_gaps)
//2、在匹配詞'distributed engine'之間不允許包含'redis'字段
POST software/_search
{
  "query": {
    "intervals":{
      "desc":{
        "match":{
          "query":"distributed engine",
          "max_gaps": 3,
          "filter":{
            "not_containing":{
              "match":{
                "query": "redis"
              }
            }
          }
        }
      }
    }
  }
}

//結果返回,可結合不同情況分別測試
{
  "took" : 0,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 0.19999999,
    "hits" : [
      {
        "_index" : "software",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 0.19999999,
        "_source" : {
          "title" : "elasticsearch",
          "desc" : "Elasticsearch is the distributed search and analytics engine at the heart of the Elastic Stack"
        }
      },
      {
        "_index" : "software",
        "_type" : "_doc",
        "_id" : "4",
        "_score" : 0.19999999,
        "_source" : {
          "title" : "elasticsearch",
          "desc" : "distributed search and analytics engine at the heart of the Elastic Stack"
        }
      }
    ]
  }
}


//查詢的字段'distributed engine'要在'redis'之前
GET software/_search
{
  "query": {
    "intervals":{
      "desc":{
        "match":{
          "query":"distributed engine",
          "max_gaps": 3,
          "filter":{
            "before":{
              "match":{
                "query": "redis"
              }
            }
          }
        }
      }
    }
  }
}

//結果返回
{
  "took" : 0,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 0.19999999,
    "hits" : [
      {
        "_index" : "software",
        "_type" : "_doc",
        "_id" : "5",
        "_score" : 0.19999999,
        "_source" : {
          "title" : "elasticsearch",
          "desc" : "distributed search redis analytics engine redis"
        }
      }
    ]
  }
}



GET software/_search
{
  "query": {
    "intervals":{
      "desc":{
        "match":{
          "query":"distributed engine",
          "filter":{
            "script":{
              "source":"interval.start > 1 && interval.end < 10 && interval.gaps == 3"
            }
          }
        }
      }
    }
  }
}


{
  "took" : 0,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 0.19999999,
    "hits" : [
      {
        "_index" : "software",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 0.19999999,
        "_source" : {
          "title" : "elasticsearch",
          "desc" : "Elasticsearch is the distributed search and analytics engine at the heart of the Elastic Stack"
        }
      }
    ]
  }
}

最小化
intervals查詢總是最小化間隔(interval)以保證查詢時間在線性範圍內;這在有時候會出現令人不解的情況,尤其是在使用了max_gaps參數或filter的情況下;例如以下查詢希望’library API’短語中包含code的查詢:

//
GET software/_search
{
  "query": {
    "intervals":{
      "desc":{
        "match":{
          "query":"library API",
          "filter":{
            "contained_by":{
              "match":{
                "query":"code"
              }
            }
          }
        }
      }
    }
  }
}

以上的查詢語句並不與短語but rather a code library and API that can easily be used匹配,可以將contained_by改成after進行匹配;

另外的一個限制是在any_of子規則查詢當中出現的重疊短語;即當一個較短短語匹配則較長短語將永遠無法匹配到,這在組合使用max_gaps時返回令人不解的結果,考慮以下的查詢:

GET software/_search
{
  "query": {
    "intervals": {
      "desc": {
        "all_of": {
          "intervals": [
            {
              "match": {
                "query": "add"
              }
            },
            {
              "any_of": {
                "intervals": [
                  {
                    "match": {
                      "query": "search"
                    }
                  },
                  {
                    "match": {
                      "query": "search capabilities"
                    }
                  }
                ]
              }
            },
            {
              "match": {
                "query": "to"
              }
            }
          ],
          "max_gaps": 0,
          "ordered": true
        }
      }
    }
  }
}

以上這個查詢將永遠也不會匹配add search capabilities to,因爲any_of的規則只會產生search,在這種情況下就需要重寫上面的查詢條件,重寫之後的條件如下:

GET software/_search
{
  "query": {
    "intervals": {
      "desc": {
        "any_of": {
          "intervals": [
            {
              "match": {
                "query": "add search capabilities to",
                "max_gaps": 0,
                "ordered": true
              }
            },
            {
              "match": {
                "query": "add search to",
                "max_gaps": 0,
                "ordered": true
              }
            }
          ]
        }
      }
    }
  }
}


//以上兩個查詢條件結果相同
{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 0.3333333,
    "hits" : [
      {
        "_index" : "software",
        "_type" : "_doc",
        "_id" : "6",
        "_score" : 0.3333333,
        "_source" : {
          "title" : "lucene",
          "desc" : "Lucene is not a complete application, but rather a code library and API that can easily be used to add search capabilities to applications"
        }
      }
    ]
  }
}

以下爲查詢的索引文檔信息

PUT software/_doc/1
{
  "title":"elasticsearch",
  "desc":"Elasticsearch is the distributed search and analytics engine at the heart of the Elastic Stack"
}

PUT software/_doc/2
{
  "title":"redis",
  "desc":"Redis is an open source, in-memory data structure store, used as a database, cache and message broker"
}

PUT software/_doc/3
{
  "title":"Luence",
  "desc":"Lucene Core is a Java library providing powerful indexing and search features, as well as spellchecking, hit highlighting and advanced analysis/tokenization capabilities"
}

PUT software/_doc/4
{
  "title":"elasticsearch",
  "desc":"distributed search and analytics engine at the heart of the Elastic Stack"
}

PUT software/_doc/5
{
  "title":"elasticsearch",
  "desc":"distributed search redis analytics engine redis"
}


PUT software/_doc/6
{
  "title":"lucene",
  "desc":"Lucene is not a complete application, but rather a code library and API that can easily be used to add search capabilities to applications"
}